MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Computer Methods and Programs in Biomedicine' source. Thu, 09 Feb 2012 22:12:27 +0100 http://www.medworm.com/index.php?rid=5625345&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002665%2Fabstract%3Frss%3Dyes Abstract: This paper describes feature extraction methods using higher order statistics (HOS) of wavelet packet decomposition (WPD) coefficients for the purpose of automatic heartbeat recognition. The method consists of three stages. First, the wavelet package coefficients (WPC) are calculated for each different type of ECG beat. Then, higher order statistics of WPC are derived. Finally, the obtained feature set is used as input to a classifier, which is based on k-NN algorithm. The MIT-BIH arrhythmia database is used to obtain the ECG records used in this study. All heartbeats in the arrhythmia database are grouped into five main heartbeat classes. The classification accuracy of the proposed system is measured by average sensitivity of 90%, average selectivity of 92% and average specifici... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5625345 Wed, 25 Jan 2012 04:50:49 +0100 5625345 http://www.medworm.com/index.php?rid=5625344&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002446%2Fabstract%3Frss%3Dyes Abstract: Cone Beam Computed Tomography (CBCT) is widely used in radiation therapy for verifying treatment areas, since it provides three-dimensional image reconstruction of those tumour regions under inspection. However, organ motion is problematic during the scanning process, it causes motion artefacts on the CBCT image and can lead to mispositioning for the subsequent treatment. Moreover, patient dose is also considerable and there is a need for methods which yield acceptable image quality with as few X-ray images as possible. Although methods have been developed to handle limited projection data, such as the Algebraic Reconstruction Technique (ART); Simultaneous ART (SART); and Ordered-Subset SART (OS-SART), this study applied motion compensation to these reconstruction techniques. Roo... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5625344 Wed, 25 Jan 2012 04:50:49 +0100 5625344 http://www.medworm.com/index.php?rid=5625343&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002434%2Fabstract%3Frss%3Dyes Abstract: Uncomplicated urinary tract infection (uUTI) is a bacterial infection that affects individuals with normal urinary tracts from both structural and functional perspective. The appropriate antibiotics and treatment suggestions to individuals suffer of uUTI is an important and complex task that demands a special attention. How to decrease the unsafely use of antibiotics and their consumption is an important issue in medical treatment. Aiming to model medical decision making for uUTI treatment, an innovative and flexible approach called fuzzy cognitive maps (FCMs) is proposed to handle with uncertainty and missing information. The FCM is a promising technique for modeling knowledge and/or medical guidelines/treatment suggestions and reasoning with it. A software tool, namely FCM-uUTI... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5625343 Wed, 25 Jan 2012 04:50:49 +0100 5625343 http://www.medworm.com/index.php?rid=5625342&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002574%2Fabstract%3Frss%3Dyes Abstract: The temporomandibular joint (TMJ) is one of the most important and complex joints of the body and its pathologies affect a great percentage of the human population. The simulation of the TMJ behavior during opening, closing and chewing movements can be very useful to the understanding of this articulation by physicians, helping them to prevent or fix problems due to accidents or diseases. This work proposes a model to simulate the human TMJ behavior based on the concept of two interdependent joints. The model was conceived using multimodal information acquired from CT and MRI images of a live person, as well as motion data acquired from this same person with a magnetic motion capture device. Simulation of movement of other TMJs, based on different morphology of bones and teeth, i... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5625342 Wed, 25 Jan 2012 04:50:49 +0100 5625342 http://www.medworm.com/index.php?rid=5625341&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002586%2Fabstract%3Frss%3Dyes Abstract: In the clinical practice of psychiatry, presence or absence of particular symptoms is based on the subjective interpretation, by the clinician, of mental and behavioural descriptions offered by the patient. However, this subjectivity that characterizes the diagnostic decision making process may limit the reliability of diagnosis. In this current study, the pairwise comparisons (PC) method is used to investigate whether the psychometric properties of a medical screening questionnaire can be improved. The pilot data described herein did indeed demonstrate that modest improvements in diagnostic accuracy could be achieved using PC, and provides early evidence that the inconsistency produced by subjective clinical ratings can be reduced using this method, thus providing impetus for fu... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5625341 Wed, 25 Jan 2012 04:50:49 +0100 5625341 http://www.medworm.com/index.php?rid=5625340&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002690%2Fabstract%3Frss%3Dyes Abstract: Predicting significant fibrosis or cirrhosis in patients with hepatitis C virus has persistently preoccupied the research agenda of many specialized research centers. Many studies have been conducted to evaluate the use of readily available laboratory tests to predict significant fibrosis or cirrhosis with the purpose to substantially reduce the number of biopsies performed. Although many of them reported significant predictive values of several serum markers for the diagnosis of cirrhosis, none of these diagnostic techniques was successful in accurately predicting early stages of liver fibrosis. Therefore, in this study a single stage classification model and a multistage stepwise classification model based on Neural Network, Decision Tree, Logistic Regression, and Nearest Neigh... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5625340 Wed, 25 Jan 2012 04:50:49 +0100 5625340 http://www.medworm.com/index.php?rid=5625339&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002562%2Fabstract%3Frss%3Dyes In conclusion, the results of this study indicate that the proposed classifiers may contribute to easy the diagnostic of COPD by using forced oscillation measurements. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5625339 Wed, 25 Jan 2012 04:50:49 +0100 5625339 http://www.medworm.com/index.php?rid=5625338&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260712000193%2Fabstract%3Frss%3Dyes (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5625338 Wed, 25 Jan 2012 04:50:49 +0100 5625338 http://www.medworm.com/index.php?rid=5557063&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000708%2Fabstract%3Frss%3Dyes Abstract: Texture analysis provides a means to quantify complex changes in microscope images. We previously showed that cytoplasmic poly-adenylated mRNAs form mRNA granules in post-ischemic neurons and that these granules correlated with protein synthesis inhibition and hence cell death. Here we utilized the texture analysis software MaZda to quantify mRNA granules in photomicrographs of the pyramidal cell layer of rat hippocampal region CA3 around 1h of reperfusion after 10min of normothermic global cerebral ischemia. At 1h reperfusion, we observed variations in the texture of mRNA granules amongst samples that were readily quantified by texture analysis. Individual sample variation was consistent with the interpretation that animal-to-animal variations in mRNA granules reflected the time... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5557063 Sun, 01 Jan 2012 05:00:00 +0100 5557063 http://www.medworm.com/index.php?rid=5557062&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002051%2Fabstract%3Frss%3Dyes Abstract: In teleconsultation sessions, a critical dependency exists between the image contents and the type and sequential order of the image processing commands used by the various participants. Accordingly, for re-entrant/late users, a significant challenge exists in restoring the image contents of the teleconsultation session in such a way that all the participants maintain a consistent view of the medical images. In this paper, this problem is resolved using a novel recovery mechanism comprising two major components, namely an enhanced content-recording scheme designated as three-level indexing hierarchy (TIH) and a prioritized recovery policy. TIH maintains a record of all the commands which affect the appearance of each of medical images such that when a restoration process is requi... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5557062 Sun, 01 Jan 2012 05:00:00 +0100 5557062 http://www.medworm.com/index.php?rid=5557061&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002063%2Fabstract%3Frss%3Dyes Abstract: Considering the difficulty in selecting correct insulin doses and the problem of hyper- and hypoglycemia episodes in type 1 diabetes, dosage-aid systems are very useful for these patients. A model-based approach to this problem must unavoidably consider uncertainty sources such as large intra-patient variability and food intake. In the present study, postprandial glucose is predicted considering this uncertain information using modal interval analysis. This approach calculates a safer prediction of possible hyper- and hypoglycemia episodes induced by insulin therapy for an individual patient's parameters and integrates this information into a dosage-aid system. Predictions of a patient's postprandial glucose at 5-h intervals are used to predict the risk for a given therapy. Then ... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5557061 Sun, 01 Jan 2012 05:00:00 +0100 5557061 http://www.medworm.com/index.php?rid=5557060&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS016926071000204X%2Fabstract%3Frss%3Dyes Abstract: Feature test–retest reliability is proposed as a useful criterion for the selection/exclusion of features in time series classification tasks. Three sets of physiological time series are examined, EEG and ECG recordings together with measurements of neck movement. Comparisons of reliability estimates from test–retest studies with measures of feature importance from classification tasks suggest that low reliability can be used to exclude irrelevant features prior to classifier training. By removing features with low reliability an unnecessary degradation of the classifier accuracy may be avoided. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5557060 Sun, 01 Jan 2012 05:00:00 +0100 5557060 http://www.medworm.com/index.php?rid=5557059&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001987%2Fabstract%3Frss%3Dyes Abstract: In this paper, an effective paroxysmal atrial fibrillation (PAF) prediction algorithm is presented, which is based on analysis of the heart rate variability (HRV) signal. The proposed method consists of a preprocessing step for QRS detection and HRV signal extraction. In the next step, several features which can be used as markers for the prediction of PAF are extracted from the HRV signal. These features consist of spectrum features, bispectrum features, and non-linear features including sample entropy and Poincaré plot-extracted features. The spectrum features are able to discriminate the sympathetic and parasympathetic contents of the HRV signal, which are affected before PAF attacks. The bispectrum features are used in order to reveal information not presented on the spectra... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5557059 Sun, 01 Jan 2012 05:00:00 +0100 5557059 http://www.medworm.com/index.php?rid=5557058&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001999%2Fabstract%3Frss%3Dyes Abstract: Single-photon emission computed tomography (SPECT) images alone are difficult to understand in diagnosis, since anatomical structures are absent from the data. Studies on combination attempt to locate functional changes of the SPECT image by the magnetic resonance (MR) image. Due to the low similarity between original images, fused results are always darkened, obscured or loss some crucial anatomical structures. This paper has solved these problems by the variable-weight matrix which is estimated by minimizing the cost function using the simplex method. Under the generalized intensity-hue-saturation (GIHS) framework, the multiscaled analysis is presented for a better detail preservation. Besides, interactive approaches are discussed for the gradual variation between original imag... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5557058 Sun, 01 Jan 2012 05:00:00 +0100 5557058 http://www.medworm.com/index.php?rid=5557057&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001768%2Fabstract%3Frss%3Dyes Abstract: There are relatively few institutions that have developed clinical data warehouses, containing patient data from the point of care. Because of the various care practices, data types and definitions, and the perceived incompleteness of clinical information systems, the development of a clinical data warehouse is a challenge.In order to deal with managerial and clinical information needs, as well as educational and research aims that are important in the setting of a university hospital, Erasmus Medical Center Rotterdam, The Netherlands, developed a data warehouse incrementally. In this paper we report on the in-house development of an integral part of the data warehouse specifically for the intensive care units (ICU-DWH). It was modeled using Atos Origin Metadata Frame method. The... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5557057 Sun, 01 Jan 2012 05:00:00 +0100 5557057 http://www.medworm.com/index.php?rid=5557056&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS016926071000177X%2Fabstract%3Frss%3Dyes Abstract: The purpose of this study was to compare the accuracy of the estimated innervation zone (IZ) locations obtained from cross-correlation, the minimum amplitude, and maximum center frequency criteria. Eight healthy men (mean±SD age=23.0±4.3 yrs) performed isometric muscle actions of the leg extensors, and 15 separate bipolar surface electromyographic (EMG) signals were detected from the vastus lateralis. A custom software program was used to estimate the location of the IZ based on: (1) the EMG channel that demonstrated the lowest amplitude, (2) the EMG channel that showed the highest mean frequency, and (3) the EMG channel that demonstrated the lowest peak cross-correlation between the signals from adjacent channels. The IZ location estimates from the lowest amplitude and highest... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5557056 Sun, 01 Jan 2012 05:00:00 +0100 5557056 http://www.medworm.com/index.php?rid=5557055&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001653%2Fabstract%3Frss%3Dyes Abstract: Model reduction techniques have shown to constitute a valuable tool for real-time simulation in surgical environments and other fields. However, some limitations, imposed by real-time constraints, have not yet been overcome. One of such limitations is the severe limitation in time (established in 500Hz of frequency for the resolution) that precludes the employ of Newton-like schemes for solving non-linear models as the ones usually employed for modeling biological tissues. In this work we present a technique able to deal with geometrically non-linear models, based on the employ of model reduction techniques, together with an efficient non-linear solver. Examples of the performance of the technique over some examples will be given. (Source: Computer Methods and Programs in Biomedi... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5557055 Sun, 01 Jan 2012 05:00:00 +0100 5557055 http://www.medworm.com/index.php?rid=5557054&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711003312%2Fabstract%3Frss%3Dyes (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5557054 Sun, 01 Jan 2012 05:00:00 +0100 5557054 http://www.medworm.com/index.php?rid=5397668&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000289%2Fabstract%3Frss%3Dyes Abstract: This paper presents the application of multidimensional scaling (MDS) analysis to data emerging from noninvasive lung function tests, namely the input respiratory impedance. The aim is to obtain a geometrical mapping of the diseases in a 3D space representation, allowing analysis of (dis)similarities between subjects within the same pathology groups, as well as between the various groups. The adult patient groups investigated were healthy, diagnosed chronic obstructive pulmonary disease (COPD) and diagnosed kyphoscoliosis, respectively. The children patient groups were healthy, asthma and cystic fibrosis. The results suggest that MDS can be successfully employed for mapping purposes of restrictive (kyphoscoliosis) and obstructive (COPD) pathologies. Hence, MDS tools can be furthe... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397668 Fri, 11 Nov 2011 16:39:29 +0100 5397668 http://www.medworm.com/index.php?rid=5397667&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000666%2Fabstract%3Frss%3Dyes Abstract: The paper discusses the application of a direct adaptive controller to a pressure controlled artificial ventilation problem. In pressure controlled ventilators, the manipulated variable is the maximum flow applied to the patient during the active phase (inspiration), and the regulated variable is the peak pressure at end-inspiration. This simulation case study focuses on patients diagnosed with Chronic Obstructive Pulmonary Disease (COPD), which require artificial/mechanical ventilation. An adaptive PID controller ensures peak pressures below critical values, by manipulating the flow delivered by the ventilator. The simulation study is performed on fractional-order models of the respiratory impedance identified from lung function data obtained from 21 COPD patients. Additional si... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397667 Fri, 11 Nov 2011 16:39:29 +0100 5397667 http://www.medworm.com/index.php?rid=5397666&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002033%2Fabstract%3Frss%3Dyes Abstract: Normal and abnormal brains can be segmented by registering the target image with an atlas. Here, an atlas is defined as the combination of an intensity image (template) and its segmented image (the atlas labels). After registering the atlas template and the target image, the atlas labels are propagated to the target image. We define this process as atlas-based segmentation. In recent years, researchers have investigated registration algorithms to match atlases to query subjects and also strategies for atlas construction. In this paper we present a review of the automated approaches for atlas-based segmentation of magnetic resonance brain images. We aim to point out the strengths and weaknesses of atlas-based methods and suggest new research directions. We use two different criter... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397666 Fri, 11 Nov 2011 16:39:29 +0100 5397666 http://www.medworm.com/index.php?rid=5397665&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000447%2Fabstract%3Frss%3Dyes We present a method to derive the AIF on the middle cerebral artery (MCA). The algorithm draws a region of interest (ROI) where the MCA is located. Then, it uses a recursive cluster analysis on the ROI to select the arterial voxels. The algorithm had been compared on simulated data to literature state of art automatic algorithms and on clinical data to the manual procedure. On in silico data, our method allows to reconstruct the true AIF and it is less affected by partial volume effect bias than the other methods. In clinical data, automatic AIF provides CBF and MTT maps with a greater contrast level compared to manual AIF ones. Therefore, AIF obtained with the proposed method improves the estimate reliability and provides a quantitatively reliable physiological picture. (Source: Computer ... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397665 Fri, 11 Nov 2011 16:39:29 +0100 5397665 http://www.medworm.com/index.php?rid=5397664&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000691%2Fabstract%3Frss%3Dyes In this study, we introduced a new method of employing a clustering algorithm to develop a diagnostic model that can differentially diagnose a single unknown subject in a disease with well-defined group boundaries. We used three tests to assess the suitability and the accuracy required for diagnostic purposes of the four clustering algorithms we investigated (K-means, Fuzzy, Hierarchical, and Medoid Partitioning). To accomplish this goal, we studied the striatal metabolomic profile of R6/2 Huntington disease (HD) transgenic mice and that of wild type (WT) mice using high field in vivo proton NMR spectroscopy (9.4T). We tested all four clustering algorithms (1) with the original R6/2 HD mice and WT mice, (2) with unknown mice, whose status had been determined via genotyping, and (3) with th... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397664 Fri, 11 Nov 2011 16:39:29 +0100 5397664 http://www.medworm.com/index.php?rid=5397663&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711001544%2Fabstract%3Frss%3Dyes Abstract: Correlated ordinal data are common in many areas of research. The data may arise from longitudinal studies in biology, medical, or clinical fields. The prominent characteristic of these data is that the within-subject observations are correlated, whilst between-subject observations are independent. Many methods have been proposed to analyze correlated ordinal data. One way to evaluate the performance of a proposed model or the performance of small or moderate size data sets is through simulation studies. It is thus important to provide a tool for generating correlated ordinal data to be used in simulation studies. In this paper, we describe a macro program on how to generate correlated ordinal data based on R language and SAS IML. (Source: Computer Methods and Programs in Biomedi... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397663 Fri, 11 Nov 2011 16:39:29 +0100 5397663 http://www.medworm.com/index.php?rid=5397662&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711001490%2Fabstract%3Frss%3Dyes Abstract: Cohort studies are becoming essential tools in epidemiological research. In these studies, measurements are not restricted to single variables but can be seen as trajectories. Thus, an important question concerns the existence of homogeneous patient trajectories.KmL is an R package providing an implementation of k-means designed to work specifically on longitudinal data. It provides several different techniques for dealing with missing values in trajectories (classical ones like linear interpolation or LOCF but also new ones like copyMean). It can run k-means with distances specifically designed for longitudinal data (like Frechet distance or any user-defined distance). Its graphical interface helps the user to choose the appropriate number of clusters when classic criteria are n... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397662 Fri, 11 Nov 2011 16:39:29 +0100 5397662 http://www.medworm.com/index.php?rid=5397661&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710003020%2Fabstract%3Frss%3Dyes This study describes a portable computer-based handwriting assessment tool to objectively measure MHA quality scores and to detect handwriting difficulties in children. Several measures are proposed based on spatial, temporal, and grip force measurements obtained from a custom-built handwriting instrument. Thirty-five first and second grade students participated in the study, nine of whom exhibited handwriting difficulties. Students performed the MHA test and were subjectively scored based on speed and handwriting quality using five primitives: legibility, form, alignment, size, and space. Several spatial parameters are shown to correlate significantly (p (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397661 Fri, 11 Nov 2011 16:39:29 +0100 5397661 http://www.medworm.com/index.php?rid=5397660&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000678%2Fabstract%3Frss%3Dyes Abstract: Classification analysis of microarray data is widely used to reveal biological features and to diagnose various diseases, including cancers. Most existing approaches improve the performance of learning models by removing most irrelevant and redundant genes from the data. They select the marker genes which are expressed differently in normal and tumor tissues. These techniques ignore the importance of the complex functional-dependencies between genes. In this paper, we propose a new method for cancer classification which uses distinguished variations of gene–gene correlation in two sample groups. The cancer specific genetic network composed of these gene pairs contains many literature-curated prostate cancer genes, and we were successful in identifying new candidate prostate can... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397660 Fri, 11 Nov 2011 16:39:29 +0100 5397660 http://www.medworm.com/index.php?rid=5397659&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001744%2Fabstract%3Frss%3Dyes Abstract: The paper presents results of our long-term study on using image processing and data mining methods in a medical imaging. Since evaluation of modern medical images is becoming increasingly complex, advanced analytical and decision support tools are involved in integration of partial diagnostic results. Such partial results, frequently obtained from tests with substantial imperfections, are integrated into ultimate diagnostic conclusion about the probability of disease for a given patient. We study various topics such as improving the predictive power of clinical tests by utilizing pre-test and post-test probabilities, texture representation, multi-resolution feature extraction, feature construction and data mining algorithms that significantly outperform medical practice. Our lon... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397659 Fri, 11 Nov 2011 16:39:29 +0100 5397659 http://www.medworm.com/index.php?rid=5397658&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000198%2Fabstract%3Frss%3Dyes Abstract: Articular cartilage (AC) is a biological tissue that allows the distribution of mechanical loads and movement of joints. The presence of these mechanical loads influences the behavior and physiological condition of AC. The loads may cause damaged by fatigue through injuries due to repeated accumulated stresses. The aim of this work is to introduce a phenomenological mathematical model of damage caused by mechanical action. It is considered that tissue failure is a consequence of chondrocyte death and matrix loss, taking into account factors modifying fatigue resistance such as age, body mass index (BMI) and metabolic activity. The model was numerically implemented using the finite elements method and the results obtained allowed us to predict tissue failure at different loading f... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397658 Fri, 11 Nov 2011 16:39:29 +0100 5397658 http://www.medworm.com/index.php?rid=5397657&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002713%2Fabstract%3Frss%3Dyes Abstract: The rapidly increasing performance of graphics processors, improving programming support and excellent performance-price ratio make graphics processing units (GPUs) a good option for a variety of computationally intensive tasks. Within this survey, we give an overview of GPU accelerated image registration. We address both, GPU experienced readers with an interest in accelerated image registration, as well as registration experts who are interested in using GPUs. We survey programming models and interfaces and analyze different approaches to programming on the GPU. We furthermore discuss the inherent advantages and challenges of current hardware architectures, which leads to a description of the details of the important building blocks for successful implementations. (Source: Comp... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397657 Fri, 11 Nov 2011 16:39:29 +0100 5397657 http://www.medworm.com/index.php?rid=5397656&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000940%2Fabstract%3Frss%3Dyes Abstract: Active shape models (ASMs) are popular and sophisticated methods of extracting features in (especially medical) images. Here we analyse the error in placing ASM points on the boundary of the feature. By using replications, a corrected covariance matrix is presented that should reduce the effects of placement error. We show analytically and via simulations that the cumulative variability for a given number of eigenvalues retained in principal components analysis (PCA) ought to be reduced by increasing levels of point-placement error. Results for predicted errors are in excellent agreement with the set-up parameters of two simulated shapes and with anecdotal evidence from the trained experts for real data taken from the OSTEODENT project. We derive an equation for the reliability o... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397656 Fri, 11 Nov 2011 16:39:29 +0100 5397656 http://www.medworm.com/index.php?rid=5397655&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002816%2Fabstract%3Frss%3Dyes Abstract: The present study quantitatively analyzes the EEG characteristics during activations (Act) that occur during NREM sleep, and constitute elements of sleep microstructure (i.e. the Cyclic Alternating Pattern). The fractal dimension (FD) and the sample entropy (SampEn) measures were used to study the different sleep stages and the Act that build up the sleep structure. Polysomnographic recordings from 10 good sleepers were analyzed. The complexity indexes of the Act were compared with the non-activation (NAct) periods during non-REM sleep. In addition, complexity measures among the different Act subtypes (A1, A2 and A3) were analyzed. A3 presented a quite similar complexity independently of the sleep stage, while A1 and A2 showed higher complexity in light sleep than during deep sle... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397655 Fri, 11 Nov 2011 16:39:29 +0100 5397655 http://www.medworm.com/index.php?rid=5397654&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001690%2Fabstract%3Frss%3Dyes Abstract: The skin cancer was analyzed by dermoscopy helpful for dermatologists. The classification of melanoma and carcinoma such as basal cell, squamous cell, and merkel cell carcinomas tumors can be increased the sensitivity and specificity. The detection of an automated border is an important step for the correctness of subsequent phases in the computerized melanoma recognition systems. The artifacts such as, dermoscopy-gel, specular reflection and outline (skin lines, blood vessels, and hair or ruler markings) were also contained in the dermoscopic images. In this paper, we present an unsupervised approach for multiple lesion segmentation, modification of Region-based Active Contours (RACs) as well as artifact diminution steps. Iterative thresholding is applied to initialize level set... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397654 Fri, 11 Nov 2011 16:39:29 +0100 5397654 http://www.medworm.com/index.php?rid=5397653&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002422%2Fabstract%3Frss%3Dyes This study proposes a model to improve the patients’ medication compliance by reducing medication frequency.Published studies have shown that, based on the patients’ lifestyle, simplification of the medication frequency and remodeling of the medication schedule is able to help improve medication adherence. Therefore, this study tried to simplify medication frequency by combining therapies. Moreover, by adjusting according to lifestyle, the study also tries to remodel medication timing in relation to mealtimes to create personal medication schedules.In this study, we used 19,393,452 outpatient prescriptions from the National Health Insurance Research Database to verify our system (algorithm optimized). At the same time, we examined the differences between the frequency summarized by gen... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397653 Fri, 11 Nov 2011 16:39:29 +0100 5397653 http://www.medworm.com/index.php?rid=5397652&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711001155%2Fabstract%3Frss%3Dyes The objective of this work was to investigate the factors influencing the quality of empirical Bayes estimates (EBEs) of individual random effects of a mixed-effects Markov model for ordered categorical data. It was motivated by an attempt to develop a model-based dose adaptation tool for clinical use in colorectal cancer patients receiving capecitabine, which induces severe hand-and-foot syndrome (HFS) toxicity in more than a half of the patients. This simulation-based study employed a published mixed-effects model for HFS. The quality of EBEs was assessed in terms of accuracy and precision, as well as shrinkage. Three optimization algorithms were compared: simplex, quasi-Newton and adaptive random search. The investigated factors were amount of data per patient, distribution of categorie... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397652 Fri, 11 Nov 2011 16:39:29 +0100 5397652 http://www.medworm.com/index.php?rid=5397651&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002240%2Fabstract%3Frss%3Dyes This study provides us a new perspective on the analysis of acupuncture and may give potential helps on clinical treatment. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397651 Fri, 11 Nov 2011 16:39:29 +0100 5397651 http://www.medworm.com/index.php?rid=5397650&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711001891%2Fabstract%3Frss%3Dyes This article describes how a phenomenological model was developed by describing the formation pattern for the gyri occurring in the cerebral cortex by reaction diffusion equations with Turing space parameters. Numerical examples for simplified geometries of a brain were solved to study pattern formation. The finite element method was used for the numerical solution, in conjunction with the Newton–Raphson method. The numerical examples showed that the model can represent cerebral cortex fold formation and reproduce pathologies related to gyri formation, such as polymicrogyria and lissencephaly. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397650 Fri, 11 Nov 2011 16:39:29 +0100 5397650 http://www.medworm.com/index.php?rid=5397649&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002264%2Fabstract%3Frss%3Dyes Highlights: ► An evaluation of the wavelet-based de-noising efficiency for various mother wavelets. ► Parameters: SNR, image contrast and intensity of the intensity gradient of MR images. ► A brief overview of how to choose the optimum parameters of wavelet analysis.Abstract: The paper deals with techniques for the enhancement of magnetic resonance (MR) images using the wavelet analysis, which is assessed from the viewpoint of choosing the mother wavelet and the thresholding technique. Three parameters are used as objective criteria of the quality of image enhancement: the signal-to-noise ratio (SNR), image contrast, and linear approximation of edge steepness. Unlike most of the standard methods, which work exclusively with image magnitude, we also examined the influence of image pha... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397649 Fri, 11 Nov 2011 16:39:29 +0100 5397649 http://www.medworm.com/index.php?rid=5397648&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002324%2Fabstract%3Frss%3Dyes Abstract: This paper presents an intuitive nose surgery planning and simulation system, using 3D laser scan image and lateral X-ray image, to provide high quality prediction of the postoperative appearance, and design the patient specific prosthesis model automatically. After initial registration, the internal surface of soft tissue at the nose region was generated by the statistical data for soft tissue thickness adapted by the individual thickness information from the X-ray image. Then, the sketch contour of the 3D scan data on the lateral X-ray image was modified manually or adjusted automatically according to some aesthetic statistical data, to drive the simulation in real time by the state-of-the-art Laplacian surface deformation method. When satisfied with the 3D postoperative appear... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397648 Fri, 11 Nov 2011 16:39:29 +0100 5397648 http://www.medworm.com/index.php?rid=5397647&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000812%2Fabstract%3Frss%3Dyes Abstract: Population pharmacokinetic (PopPK) modeling has become increasing important in drug development because it handles unbalanced design, sparse data and the study of individual variation. However, the increased complexity of the model makes it more of a challenge to diagnose the fit. Graphics can play an important and unique role in PopPK model diagnostics. The software described in this paper, PKgraph, provides a graphical user interface for PopPK model diagnosis. It also provides an integrated and comprehensive platform for the analysis of pharmacokinetic data including exploratory data analysis, goodness of model fit, model validation and model comparison. Results from a variety of modeling fitting software, including NONMEM, Monolix, SAS and R, can be used. PKgraph is programmed... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397647 Fri, 11 Nov 2011 16:39:29 +0100 5397647 http://www.medworm.com/index.php?rid=5397646&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002269%2Fabstract%3Frss%3Dyes Abstract: This work presents a computer program for computing the 3D fractal dimension (3DFD) from magnetic-resonance images of the brain. The program is based on an algorithm that calculates the 3D box counting of the entire volume of the brain, and also of its 3D skeletonization. The validity and accuracy of the software has been confirmed using solids with well-known 3DFD values. The usefulness of the program developed is demonstrated by its successful characterization of several neurodegenerative diseases. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397646 Fri, 11 Nov 2011 16:39:29 +0100 5397646 http://www.medworm.com/index.php?rid=5397645&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000836%2Fabstract%3Frss%3Dyes In this study, we construct rotation forest (RF) ensemble classifiers of 30 machine learning algorithms to evaluate their classification performances using Parkinson's, diabetes and heart diseases from literature.While making experiments, first the feature dimension of three datasets is reduced using correlation based feature selection (CFS) algorithm. Second, classification performances of 30 machine learning algorithms are calculated for three datasets. Third, 30 classifier ensembles are constructed based on RF algorithm to assess performances of respective classifiers with the same disease data. All the experiments are carried out with leave-one-out validation strategy and the performances of the 60 algorithms are evaluated using three metrics; classification accuracy (ACC), kappa error... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397645 Fri, 11 Nov 2011 16:39:29 +0100 5397645 http://www.medworm.com/index.php?rid=5397644&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002282%2Fabstract%3Frss%3Dyes Conclusion: RFID-initiate surgical workflow control is valuable to meet the safety, quality, efficiency requirements in operation theater. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397644 Fri, 11 Nov 2011 16:39:29 +0100 5397644 http://www.medworm.com/index.php?rid=5397643&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000460%2Fabstract%3Frss%3Dyes In this study, we devised a modified iterative kurtosis-based detector algorithm, in order to enhance the de-noising performance of BS signals, and an estimation algorithm of bowel motility based on the regression modeling of the jitter and shimmer of BS signals obtained by auscultation. The correlation coefficient, coefficient of determination and errors between the colon transit times measured by a conventional radiograph and the corresponding values estimated by our method were 0.987, 0.974 and 3.5±3.3h, respectively. These results demonstrated that our method could be used as a complementary tool for the non-invasive diagnosis and monitoring of bowel motility, instead of conventional radiography. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397643 Fri, 11 Nov 2011 16:39:29 +0100 5397643 http://www.medworm.com/index.php?rid=5397642&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002270%2Fabstract%3Frss%3Dyes Abstract: This paper presents a novel digital watermarking framework using electrocardiograph (ECG) and demographic text data as double watermarks. It protects patient medical information and prevents mismatching diagnostic information. The watermarks are embedded in selected texture regions of a PET image using multi-resolution wavelet decomposition. Experimental results show that modifications in these locations are visually imperceptible. The robustness of the watermarks is verified through measurement of peak signal to noise ratio (PSNR), cross-correlation (CC%), structural similarity measure (SSIM) and universal image quality index (UIQI). Their robustness is also computed using pixel-based metrics and human visual system metrics. Additionally, beta factor (β) as an edge preservation... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397642 Fri, 11 Nov 2011 16:39:29 +0100 5397642 http://www.medworm.com/index.php?rid=5397641&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002646%2Fabstract%3Frss%3Dyes Abstract: In this paper, a novel P300-based concealed information test (CIT) method was proposed to improve the efficiency of differentiating deception and truth-telling. Thirty subjects including the guilty and innocent performed the paradigm based on three types of stimuli. In order to reduce the influence from the occasional variability of cognitive states on the CIT, several single-trials from Pz in probe stimuli within each subject were first averaged. Then the three groups of features were extracted from these averaged single-trials. Finally, two classes of feature samples were used to train a support vector machine (SVM) classifier. Meanwhile, the optimal number of averaged Pz waveforms and some other parameter values in the classifiers were determined by the cross validation proced... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397641 Fri, 11 Nov 2011 16:39:29 +0100 5397641 http://www.medworm.com/index.php?rid=5397640&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001938%2Fabstract%3Frss%3Dyes Abstract: In this work, we present a new fovea center detection method for color eye fundus images. This method is based on known anatomical constraints on the relative locations of retina structures, and mathematical morphology. The detection of this anatomical feature is a prerequisite for the computer aided diagnosis of several retinal diseases, such as Diabetic Macular Edema. The proposed method is adaptive to local illumination changes, and it is robust to local disturbances introduced by pathologies in digital color eye fundus images (e.g. exudates). Our experimental results using the DRIVE image database indicate that our method is able to detect the fovea center in 37 out of 37 images (i.e. with a success rate of 100%). Using the DIARETDB1 database, our method was able to detect th... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397640 Fri, 11 Nov 2011 16:39:29 +0100 5397640 http://www.medworm.com/index.php?rid=5397639&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002956%2Fabstract%3Frss%3Dyes Abstract: Both sample entropy and approximate entropy are measurements of complexity. The two methods have received a great deal of attention in the last few years, and have been successfully verified and applied to biomedical applications and many others. However, the algorithms proposed in the literature require O(N2) execution time, which is not fast enough for online applications and for applications with long data sets. To accelerate computation, the authors of the present paper have developed a new algorithm that reduces the computational time to O(N3/2)) using O(N) storage. As biomedical data are often measured with integer-type data, the computation time can be further reduced to O(N) using O(N) storage. The execution times of the experimental results with ECG, EEG, RR, and DNA sig... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397639 Fri, 11 Nov 2011 16:39:29 +0100 5397639 http://www.medworm.com/index.php?rid=5397638&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000745%2Fabstract%3Frss%3Dyes Abstract: Epilepsy is one of the most common neurological disorders characterized by transient and unexpected electrical disturbance of the brain. The electroencephalogram (EEG) is an invaluable measurement for the purpose of assessing brain activities, containing information relating to the different physiological states of the brain. It is a very effective tool for understanding the complex dynamical behavior of the brain. This paper presents the application of empirical mode decomposition (EMD) for analysis of EEG signals. The EMD decomposes a EEG signal into a finite set of bandlimited signals termed intrinsic mode functions (IMFs). The Hilbert transformation of IMFs provides analytic signal representation of IMFs. The area measured from the trace of the analytic IMFs, which have circu... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397638 Fri, 11 Nov 2011 16:39:29 +0100 5397638 http://www.medworm.com/index.php?rid=5397637&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002907%2Fabstract%3Frss%3Dyes Abstract: This paper presents a new approach called clustering technique-based least square support vector machine (CT-LS-SVM) for the classification of EEG signals. Decision making is performed in two stages. In the first stage, clustering technique (CT) has been used to extract representative features of EEG data. In the second stage, least square support vector machine (LS-SVM) is applied to the extracted features to classify two-class EEG signals. To demonstrate the effectiveness of the proposed method, several experiments have been conducted on three publicly available benchmark databases, one for epileptic EEG data, one for mental imagery tasks EEG data and another one for motor imagery EEG data. Our proposed approach achieves an average sensitivity, specificity and classification ac... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397637 Fri, 11 Nov 2011 16:39:29 +0100 5397637 http://www.medworm.com/index.php?rid=5397636&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000654%2Fabstract%3Frss%3Dyes Abstract: The performance of eight machine learning classifiers were compared with three aphasia related classification problems. The first problem contained naming data of aphasic and non-aphasic speakers tested with the Philadelphia Naming Test. The second problem included the naming data of Alzheimer and vascular disease patients tested with Finnish version of the Boston Naming Test. The third problem included aphasia test data of patients suffering from four different aphasic syndromes tested with the Aachen Aphasia Test. The first two data sets were small. Therefore, the data used in the tests were artificially generated from the original confrontation naming data of 23 and 22 subjects, respectively. The third set contained aphasia test data of 146 aphasic speakers and was used as suc... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397636 Fri, 11 Nov 2011 16:39:29 +0100 5397636 http://www.medworm.com/index.php?rid=5397635&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002804%2Fabstract%3Frss%3Dyes Abstract: Optimizing the orthopaedic screws can greatly improve their biomechanical performances. However, a methodical design optimization approach requires a long time to search the best design. Thus, the surrogate objective functions of the orthopaedic screws should be accurately developed. To our knowledge, there is no study to evaluate the strengths and limitations of the surrogate methods in developing the objective functions of the orthopaedic screws. Three-dimensional finite element models for both the tibial locking screws and the spinal pedicle screws were constructed and analyzed. Then, the learning data were prepared according to the arrangement of the Taguchi orthogonal array, and the verification data were selected with use of a randomized selection. Finally, the surrogate ob... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397635 Fri, 11 Nov 2011 16:39:29 +0100 5397635 http://www.medworm.com/index.php?rid=5397634&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002045%2Fabstract%3Frss%3Dyes Conclusion: This simulation study encourages the use of Poisson regression models in estimating the peak-to-trough ratio of seasonal variation as opposed to the geometrical model. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397634 Fri, 11 Nov 2011 16:39:29 +0100 5397634 http://www.medworm.com/index.php?rid=5397633&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002075%2Fabstract%3Frss%3Dyes Abstract: In this paper, the problem of tackling uncertainty in the prediction of postprandial blood glucose is analyzed. Two simulation approaches, Monte Carlo and interval models, are studied and compared. Interval simulation is carried out using modal interval analysis. Simulation of a glucoregulatory model with uncertainty in insulin sensitivities, glucose absorption and food intake is carried out using both methods. Interval simulation is superior in predicting all severe and mild hyper- and hypoglycemia episodes. Furthermore, much less computational time is required for interval simulation than for Monte Carlo simulation. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397633 Fri, 11 Nov 2011 16:39:29 +0100 5397633 http://www.medworm.com/index.php?rid=5397632&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711001167%2Fabstract%3Frss%3Dyes Highlights: ► By using the wavelet analysis, we study normal and pathological a-wave ERG component. ► Achromatopsia, a photoreceptoral disease affecting the cones, is investigated. ► The aim is to obtain frequency-temporal features useful in clinical diagnosis. ► The number of stable frequencies measures the photoreceptoral functional integrity.Abstract: Most biomedical signals are non-stationary. The knowledge of their frequency content and temporal distribution is then useful in a clinical context. The wavelet analysis is appropriate to achieve this task. The present paper uses this method to reveal hidden characteristics and anomalies of the human a-wave, an important component of the electroretinogram since it is a measure of the functional integrity of the photoreceptors. We h... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397632 Fri, 11 Nov 2011 16:39:29 +0100 5397632 http://www.medworm.com/index.php?rid=5397631&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000721%2Fabstract%3Frss%3Dyes Abstract: In the present study, an adaptation of the Markov Random Field (MRF) segmentation model, by means of the stationary wavelet transform (SWT), applied to complementary DNA (cDNA) microarray images is proposed (WMRF). A 3-level decomposition scheme of the initial microarray image was performed, followed by a soft thresholding filtering technique. With the inverse process, a Denoised image was created. In addition, by using the Amplitudes of the filtered wavelet Horizontal and Vertical images at each level, three different Magnitudes were formed. These images were combined with the Denoised one to create the proposed SMRF segmentation model. For numerical evaluation of the segmentation accuracy, the segmentation matching factor (SMF), the Coefficient of Determination (r2), and the co... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397631 Fri, 11 Nov 2011 16:39:29 +0100 5397631 http://www.medworm.com/index.php?rid=5397630&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002756%2Fabstract%3Frss%3Dyes (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5397630 Fri, 11 Nov 2011 16:39:29 +0100 5397630 http://www.medworm.com/index.php?rid=5322030&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000241%2Fabstract%3Frss%3Dyes Abstract: In this paper, we present a mathematical model, which mimics the bronchial resistances of human's lung in an expiratory act. The model is implemented in Matlab. The inputs that are used in this model derive from spirometry test. This model is able to study a physiologic condition, a pathologic one and the patient's follow up after drug treatment. We split our study into two parts. The first one focuses the analysis on the gas fluido dynamic inside of the respiratory pathways. The second part takes care of the pressure equilibrium in the exchange zone. We use the outputs that derive from the second subsystem to solve the Bernoulli's equation of the first part. The model was validated with data provided from “Clinical Physiology Institute” of CNR and G. Monasterio Foundation of... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322030 Sun, 16 Oct 2011 18:10:43 +0100 5322030 http://www.medworm.com/index.php?rid=5322029&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000824%2Fabstract%3Frss%3Dyes Abstract: The purpose of this study was to compare the results of different hierarchical models in engineering analysis applied to dentistry with 2D and 3D models of a tooth and its supporting structures under 100N occlusal loading at 45° and examine the reliability of simplified 2D models in dental research. Five models were built from computed-tomography scans: four 2D models with Plane Strain and Plane Stress State with linear triangular and quadratic quadrilateral elements and one 3D model. The finite element results indicated that the stress distribution was similar qualitatively in all models but the stress magnitude was quite different. It was concluded that 2D models are acceptable when investigating the biomechanical behavior of upper central incisor qualitatively. However, quant... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322029 Sun, 16 Oct 2011 18:10:43 +0100 5322029 http://www.medworm.com/index.php?rid=5322028&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711001969%2Fabstract%3Frss%3Dyes Conclusion: A novel formulation is now available to deal with problems occurring in a clinical diagnostic decision support system with multi-domain KBs. The utilization of this formulation will help in the development of more integrated KBs with greater focused knowledge domains. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322028 Sun, 16 Oct 2011 18:10:43 +0100 5322028 http://www.medworm.com/index.php?rid=5322027&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002671%2Fabstract%3Frss%3Dyes Abstract: Observing recurrent event processes at discrete, possibly random times produces panel count data. Modeling panel count data is challenging because the event process may be associated with the observation pattern and censoring time. Various methods have been proposed to fit flexible semiparametric regression models, but no software is available to practitioners. We develop an R package spef that fits semiparametric regression models for panel count data. Existing methods in the literature are implemented as well as our recently developed estimating equations approach. Some of the implemented methods allow informative observation and censoring scheme. The package usage is illustrated with a well-known bladder tumor data set. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322027 Sun, 16 Oct 2011 18:10:43 +0100 5322027 http://www.medworm.com/index.php?rid=5322026&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002725%2Fabstract%3Frss%3Dyes Abstract: Because of the high cost and time constraints for clinical trials, researchers often need to determine the smallest sample size that provides accurate inferences for a parameter of interest. Although most experimenters have employed frequentist sample-size determination methods, the Bayesian paradigm offers a wide variety of sample-size determination methodologies. Bayesian sample-size determination methods are becoming increasingly more popular in clinical trials because of their flexibility and easy interpretation inferences. Recently, Bayesian approaches have been used to determine the sample size of a single Poisson rate parameter in a clinical trial setting. In this paper, we extend these results to the comparison of two Poisson rates and develop methods for sample-size dete... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322026 Sun, 16 Oct 2011 18:10:43 +0100 5322026 http://www.medworm.com/index.php?rid=5322025&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000174%2Fabstract%3Frss%3Dyes We describe a SAS macro that implements the 2-sample clustered logrank test for data where the entire cluster is randomized to the same treatment group. We discuss the theory and applications behind this test as well as details of the SAS code. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322025 Sun, 16 Oct 2011 18:10:43 +0100 5322025 http://www.medworm.com/index.php?rid=5322024&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000186%2Fabstract%3Frss%3Dyes This study suggests that a strict spatial cohorting might be ineffective, if it is not combined with personnel cohorting. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322024 Sun, 16 Oct 2011 18:10:43 +0100 5322024 http://www.medworm.com/index.php?rid=5322023&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000228%2Fabstract%3Frss%3Dyes Abstract: Biotin is an essential water-soluble vitamin crucial for maintaining normal body functions. The importance of biotin for human health has been under-appreciated but there is plenty of opportunity for future research with great importance for human health. Currently, carrying out predictions of biotin metabolism involves tedious manual manipulations. In this paper, we report the development of BiotinNet, an internet based program that uses Bayesian networks to integrate published data on various aspects of biotin metabolism. Users can provide a combination of values on the levels of biotin related metabolites to obtain the predictions on other metabolites that are not specified. As an inherent feature of Bayesian networks, the uncertainty of the prediction is also quantified and r... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322023 Sun, 16 Oct 2011 18:10:43 +0100 5322023 http://www.medworm.com/index.php?rid=5322022&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000964%2Fabstract%3Frss%3Dyes Abstract: The incorporation of electronic health care in medical institutions will benefit and thus further boost the collaborations in medical research among clinics and research institutions. However, privacy regulations and security concerns make such collaborations very restricted. In this paper, we propose privacy preserving models for survival curves comparison based on logrank test, in order to perform better survival analysis through the collaboration of multiple medical institutions and protect the data privacy. We distinguish two collaboration scenarios and for each scenario we present a privacy preserving model for logrank test. We conduct experiments on the real medical data to evaluate the effectiveness of our proposed models. (Source: Computer Methods and Programs in Biomedic... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322022 Sun, 16 Oct 2011 18:10:43 +0100 5322022 http://www.medworm.com/index.php?rid=5322021&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711001209%2Fabstract%3Frss%3Dyes Abstract: In the case of an unexpected high frequency of serious adverse events (SAE), statistical methods are needed to help in the decision making process as to continuation of accrual to the trial. This paper describes an R package, named SAE that implements a method recently developed by defining stopping rules after each observed SAE. The package function control for excessive toxicity either during the trial at the observation of each SAE (function SAE) or during the planning phase of a clinical trial (function DESIGN). This description and the package documentation are complementary to help the users to apply the method. The main difficulty in the implementation of the method is the choice of a priori parameters. Data from an ongoing clinical trial are presented as an example to imp... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322021 Sun, 16 Oct 2011 18:10:43 +0100 5322021 http://www.medworm.com/index.php?rid=5322020&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711001210%2Fabstract%3Frss%3Dyes In this study, we designed and implemented a distributed PACS system, namely DIPACS, for small and medium scale medical networks. DIPACS forms a virtual organization by combining the storage of health centers and providing transparent access to images. In this study, we introduce the DIPACS architecture together with the implementation details. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322020 Sun, 16 Oct 2011 18:10:43 +0100 5322020 http://www.medworm.com/index.php?rid=5322019&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711001532%2Fabstract%3Frss%3Dyes Abstract: The direct observation of cells over time using time-lapse microscopy can provide deep insights into many important biological processes. Reliable analyses of motility, proliferation, invasive potential or mortality of cells are essential to many studies involving live cell imaging and can aid in biomarker discovery and diagnostic decisions. Given the vast amount of image- and time-series data produced by modern microscopes, automated analysis is a key feature to capitalize the potential of time-lapse imaging devices. To provide fast and reproducible analyses of multiple aspects of cell behaviour, we developed TimeLapseAnalyzer. Apart from general purpose image enhancements and segmentation procedures, this extensible, self-contained, modular cross-platform package provides dedic... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322019 Sun, 16 Oct 2011 18:10:43 +0100 5322019 http://www.medworm.com/index.php?rid=5322018&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002057%2Fabstract%3Frss%3Dyes Abstract: This paper describes a web-based system for enabling remote monitoring of patients with Parkinson's disease (PD) and supporting clinicians in treating their patients. The system consists of a patient node for subjective and objective data collection based on a handheld computer, a service node for data storage and processing, and a web application for data presentation. Using statistical and machine learning methods, time series of raw data are summarized into scores for conceptual symptom dimensions and an “overall test score” providing a comprehensive profile of patient's health during a test period of about one week. The handheld unit was used quarterly or biannually by 65 patients with advanced PD for up to four years at nine clinics in Sweden. The IBM Computer System Usa... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322018 Sun, 16 Oct 2011 18:10:43 +0100 5322018 http://www.medworm.com/index.php?rid=5322017&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711001945%2Fabstract%3Frss%3Dyes Highlights: ► We used combination of fractal analysis with Independent Component Analysis for the decomposition and identification of the fractal complexity sources in snail Br neuron activity induced by static magnetic field. ► We have isolated two independent components of the empirical fractal dimension distributions which represent the sources of fractal waveforms complexity of Br neuron activity in particular experimental conditions. ► We have shown that there could be two opposite intrinsic mechanisms (plasticity and elasticity) in single snail Br neuron response to static magnetic field stimulation.Abstract: We applied a combination of fractal analysis and Independent Component Analysis (ICA) method to detect the sources of fractal complexity in snail Br neuron activity induce... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322017 Sun, 16 Oct 2011 18:10:43 +0100 5322017 http://www.medworm.com/index.php?rid=5322016&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002239%2Fabstract%3Frss%3Dyes Abstract: Optical coherence tomography (OCT) is commonly used to investigate the layers of the retina including retinal nerve fiber layer (RNFL) and retinal pigment epithelium (RPE). OCT images are altered by vessels on the retinal surface producing artefacts. We propose a new approach to compensate for these artefacts and enhance quality of OCT images. A total of 28 (20 normal and 8 glaucoma subjects) OCT images were obtained using Spectralis (Heidelberg, Germany). Shadows were detected along the image and compensated by the A-Scan intensity difference from surrounding non-affected areas. Images were then segmented and the area and thickness of RNFL and RPE were measured and compared. 10 subjects were tested twice to determine the effect of this on reproducibility of measurements. Shadow-... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322016 Sun, 16 Oct 2011 18:10:43 +0100 5322016 http://www.medworm.com/index.php?rid=5322015&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000939%2Fabstract%3Frss%3Dyes We report here that cardiac FP averaging can yield higher-quality signals than original individual FPs, and therefore promise more accurate detection of different phases and analysis of the cardiac FP signal. Averaged signals improved the signal-to-noise ratio (SNR), and obtaining reliable averages required approximately 50 cardiac cycles. We therefore propose that routine cardiac FP averaging can serve as a tool to compare the effects of different experimental conditions or stimuli on the properties of cardiac FPs. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322015 Sun, 16 Oct 2011 18:10:43 +0100 5322015 http://www.medworm.com/index.php?rid=5322014&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000794%2Fabstract%3Frss%3Dyes Abstract: A non-linear visco-elastic constitutive model is adopted to describe the relaxation phenomena of the periodontal ligament (PDL). The introduction of a non-linear formulation of visco-elasticity is necessary because experimental data from the literature referring to animal models show that the relaxation rate depends on the level of strain applied. In particular, the percentage of relaxation increases with decrease of the applied strain. The constitutive model is consistent with the non-linear elastic behavior of the PDL in the case of high rate loading and large strains attained by the tissue. A hyperelastic formulation is adopted for the elastic behavior of the PDL and this formulation is developed adopting suitable measures of stress and strain. The anisotropy of the tissue ind... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322014 Sun, 16 Oct 2011 18:10:43 +0100 5322014 http://www.medworm.com/index.php?rid=5322013&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS016926071100071X%2Fabstract%3Frss%3Dyes Abstract: Competing risks data usually arises in studies in which the death or failure of an individual or an item may be classified into one of k≥2 mutually exclusive causes. In this paper a simple competing risks distribution is proposed as a possible alternative to the Exponential or Weibull distributions usually considered in lifetime data analysis. We consider the case when the competing risks have a Lindley distribution. Also, we assume that the competing events are uncorrelated and that each subject can experience only one type of event at any particular time. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322013 Sun, 16 Oct 2011 18:10:43 +0100 5322013 http://www.medworm.com/index.php?rid=5322012&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000204%2Fabstract%3Frss%3Dyes This article concludes with an analytical example that examines the performance of the proposed tests and the confidence interval of the association coefficient. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322012 Sun, 16 Oct 2011 18:10:43 +0100 5322012 http://www.medworm.com/index.php?rid=5322011&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000216%2Fabstract%3Frss%3Dyes Abstract: The purpose of this work is to introduce the reader to an Add-in implementation, Decom. This implementation provides the whole processing requirements for analysis of dimeric spectra. General linear and nonlinear decomposition algorithms were integrated as an Excel Add-in for easy installation and usage. In this work, the results of several samples investigations were compared to those obtained by Datan. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322011 Sun, 16 Oct 2011 18:10:43 +0100 5322011 http://www.medworm.com/index.php?rid=5322010&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002841%2Fabstract%3Frss%3Dyes Abstract: Two-dimensional finite element models of cadaveric femoral stiffness were developed to study their suitability as surrogates of bone stiffness and strength, using two-dimensional representations of femoral geometry and bone mineral density distributions. If successfully validated, such methods could be clinically applied to estimate patient bone stiffness and strength using simpler and less costly radiographs. Two-dimensional femur images were derived by projection of quantitative computed tomography scans of 22 human cadaveric femurs. The same femurs were fractured in a fall on the hip configuration. Femoral stiffness and fracture load were measured, and high speed video was recorded. Digital image correlation analysis was used to calculate the strain distribution from the high ... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322010 Sun, 16 Oct 2011 18:10:43 +0100 5322010 http://www.medworm.com/index.php?rid=5322009&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002737%2Fabstract%3Frss%3Dyes In this study, we investigate how illumination-collection parameters (e.g., collection angle and source–detector separation) influence the ability to measure fluorophore lifetime and tissue layer thickness. Decay curves are simulated with a Monte Carlo TRF light propagation model. Multi-exponential iterative deconvolution is used to determine lifetimes and fractional signal contributions. The ability to detect changes in mucosal thickness is optimized by probes that selectively interrogate regions superficial to the mucosal–submucosal boundary. Optimal accuracy in simultaneous determination of lifetimes in both layers is achieved when each layer contributes 40–60% of the signal. These results indicate that depth-selective approaches to TRF have the potential to enhance disease detect... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322009 Sun, 16 Oct 2011 18:10:43 +0100 5322009 http://www.medworm.com/index.php?rid=5322008&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002634%2Fabstract%3Frss%3Dyes Conclusion: Changes in RN can be used to detect noxious stimuli during surgery. RN also predicted movement in our patients under propofol–remifentanil anaesthesia. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322008 Sun, 16 Oct 2011 18:10:43 +0100 5322008 http://www.medworm.com/index.php?rid=5322007&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002993%2Fabstract%3Frss%3Dyes Abstract: The paper is a presentation of the current state of development for the Atlas of Physiology and Pathophysiology (Atlas). Our main aim is to provide a novel interactive multimedia application that can be used for biomedical education where (a) simulations are combined with tutorials and (b) the presentation layer is simplified while the underlying complexity of the model is retained. The development of the Atlas required the cooperation of many professionals including teachers, system analysts, artists, and programmers. During the design of the Atlas, tools were developed that allow for component-based creation of simulation models, creation of interactive multimedia and their final coordination into a compact unit based on the given design. The Atlas is a freely available online ... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322007 Sun, 16 Oct 2011 18:10:43 +0100 5322007 http://www.medworm.com/index.php?rid=5322006&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001719%2Fabstract%3Frss%3Dyes Abstract: Background: Opportunistic pulmonary infections are a major cause of morbidity and mortality among solid organ transplant recipients. The diagnosis of these infections is challenging because of the broad spectrum of bacteria, fungi and viruses affecting these patients and the lack of specific signs and symptoms. Treatment directed at the offending organism started as soon as possible improves survival.Objective: To develop a decision support system for the diagnosis of pulmonary infections in solid-organ transplant recipients. The model's goal is to improve the accuracy of the diagnosis and thus the appropriateness of empirical treatment.Design: The model is built using a Bayesian network (also known as causal probabilistic network). The network is based on pathogen segments which... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322006 Sun, 16 Oct 2011 18:10:43 +0100 5322006 http://www.medworm.com/index.php?rid=5322005&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002233%2Fabstract%3Frss%3Dyes Abstract: Many mathematical models have been developed to describe glucose–insulin kinetics as a means of analysing the effective control of diabetes. This paper concentrates on the structural identifiability analysis of certain well-established mathematical models that have been developed to characterise glucose–insulin kinetics under different experimental scenarios. Such analysis is a pre-requisite to experiment design and parameter estimation and is applied for the first time to these models with the specific structures considered. The analysis is applied to a basic (original) form of the Minimal Model (MM) using the Taylor Series approach and a now well-accepted extended form of the MM by application of the Taylor Series approach and a form of the Similarity Transformation approac... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322005 Sun, 16 Oct 2011 18:10:43 +0100 5322005 http://www.medworm.com/index.php?rid=5322004&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001240%2Fabstract%3Frss%3Dyes Abstract: Microorganisms growth processes are encountered in many biotechnological applications. For an increased economic benefit, optimizing their productivity is of great interest. Often the growth is inhibited by the presence in excess of other components. Inhibition determines the occurrence of multiple equilibrium points, which makes the optimal steady state reachable only from a small region of the system state space. Thus dynamic control is needed to drive the system from an initial state (characterized by a low concentration of microorganisms) to the optimal steady state. The strategy presented in this paper relies on the solutions of two optimization problems: the problem of optimal operation for maximum productivity in steady state (steady state optimization) and the problem of ... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322004 Sun, 16 Oct 2011 18:10:43 +0100 5322004 http://www.medworm.com/index.php?rid=5322003&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002312%2Fabstract%3Frss%3Dyes Abstract: To improve our understanding of the climate process and to assess the human impact on current global warming, past climate reconstruction is essential. The chemical composition of a bivalve shell is strongly coupled to environmental variations and therefore ancient shells are potential climate archives. The nonlinear nature of the relation between environmental condition (e.g. the seawater temperature) and proxy composition makes it hard to predict the former from the latter, however. In this paper we compare the ability of three nonlinear system identification methods to reconstruct the ambient temperature from the chemical composition of a shell. The comparison shows that nonlinear multi-proxy approaches are potentially useful tools for climate reconstructions and that manifold... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322003 Sun, 16 Oct 2011 18:10:43 +0100 5322003 http://www.medworm.com/index.php?rid=5322002&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001513%2Fabstract%3Frss%3Dyes Abstract: A compartmental model for the in vitro uptake kinetics of the anti-cancer agent topotecan (TPT) has been extended from a previously published model. The extended model describes the drug activity and delivery of the pharmacologically active form to the DNA target as well as the catalysis of the aldehyde dehydrogenase (ALDH) enzyme and the elimination of drug from the cytoplasm via the efflux pump. Verification of the proposed model is achieved using scanning-laser microscopy data from live human breast cancer cells. Before estimating the unknown model parameters from the experimental in vitro data it is essential to determine parameter uniqueness (or otherwise) from this imposed output structure. This is formally performed as a structural identifiability analysis, which demonstra... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322002 Sun, 16 Oct 2011 18:10:43 +0100 5322002 http://www.medworm.com/index.php?rid=5322001&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002294%2Fabstract%3Frss%3Dyes Abstract: A mathematical model for the pharmacokinetics of Hoechst 33342 following administration into a culture medium containing a population of transfected cells (HEK293 hBCRP) with a potent breast cancer resistance protein inhibitor, Fumitremorgin C (FTC), present is described. FTC is reported to almost completely annul resistance mediated by BCRP in vitro. This non-linear compartmental model has seven macroscopic sub-units, with 14 rate parameters. It describes the relationship between the concentration of Hoechst 33342 and FTC, initially spiked in the medium, and the observed change in fluorescence due to Hoechst 33342 binding to DNA. Structural identifiability analysis has been performed using two methods, one based on the similarity transformation/exhaustive modelling approach and ... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322001 Sun, 16 Oct 2011 18:10:43 +0100 5322001 http://www.medworm.com/index.php?rid=5322000&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001963%2Fabstract%3Frss%3Dyes Abstract: An important question in Systems Biology is the design of experiments that enable discrimination between two (or more) competing chemical pathway models or biological mechanisms. In this paper analysis is performed between two different models describing the kinetic mechanism of a three-substrate three-product reaction, namely the MurC reaction in the cytoplasmic phase of peptidoglycan biosynthesis. One model involves ordered substrate binding and ordered release of the three products; the competing model also assumes ordered substrate binding, but with fast release of the three products. The two versions are shown to be distinguishable; however, if standard quasi-steady-state assumptions are made distinguishability cannot be determined. Once model structure uniqueness is ensured... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5322000 Sun, 16 Oct 2011 18:10:43 +0100 5322000 http://www.medworm.com/index.php?rid=5321999&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710000593%2Fabstract%3Frss%3Dyes Abstract: Two methods of modelling the Double Peak Phenomenon in pharmacokinetics are described; both are based on compartmental models. The first method assumes that the absorption of the drug from the gut to the systemic plasma varies with the location of the drug in the gut, with negligible absorption through the jejunum. It has the advantage of clear physiological interpretation, but there are a comparatively large number of parameters to be estimated. The second method assumes simultaneous input via two parallel pathways, and has been developed with the aim of reducing the number of parameters in the model. However, this approach lacks the direct relationship to physiology. The two methods are used to model two data sets provided by AstraZeneca and a further data set from the literatu... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5321999 Sun, 16 Oct 2011 18:10:43 +0100 5321999 http://www.medworm.com/index.php?rid=5321998&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711001994%2Fabstract%3Frss%3Dyes Abstract: The use of highly active antiretroviral therapy (HAART) for suppression of measurable levels of virus in the body has greatly contributed to restoration and preservation of the immune system in HIV positive patients. However, short and long term problems associated with HAART have led to proposals for alternative treatment strategies for controlling HIV infection. In particular, structured treatment interruptions (STIs) that consist of therapy withdrawal and re-initiation according to specific criteria have been considered. The aim of these STIs was one or both of: (i) to stimulate the immune system to react to HIV, (ii) to allow re-emergence of wild-type virus and thereby reduce problems of drug resistance. However, a number of clinical trials of STIs have shown adverse outcomes... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5321998 Sun, 16 Oct 2011 18:10:43 +0100 5321998 http://www.medworm.com/index.php?rid=5321997&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002300%2Fabstract%3Frss%3Dyes Abstract: This paper considers the outcome of a formal sensitivity analysis on a series of epidemic model structures developed to study the population level effects of maternal antibodies. The analysis is used to compare the potential influence of maternally acquired immunity on various age and time domain observations of infection and serology, with and without seasonality. The results of the analysis indicate that time series observations are largely insensitive to variations in the average duration of this protection, and that age related empirical data are likely to be most appropriate for estimating these characteristics. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5321997 Sun, 16 Oct 2011 18:10:43 +0100 5321997 http://www.medworm.com/index.php?rid=5321996&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001227%2Fabstract%3Frss%3Dyes Abstract: Mathematical modelling of infectious diseases has gained growing attention in epidemiology during the last decades. The major benefits of simulating compartmental models are the prediction of the consequences of potential interventions, a deeper understanding of epidemic dynamics and clinical decision support. The main limitation is however that several parameters are based on uncertain expert guesses (default values) and are not estimated from the study data. In this paper we build a bridge between an extension of the well-known deterministic S–I–R (Susceptible–Infectious–Removed) model which can be described with differential equations and the stochastic counterpart which can be used for statistical inference if outbreak data on an individual level are available. The po... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5321996 Sun, 16 Oct 2011 18:10:43 +0100 5321996 http://www.medworm.com/index.php?rid=5321995&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002331%2Fabstract%3Frss%3Dyes This special issue of Computer Methods and Programs in Biomedicine contains a set of papers that are based on presentations that were made at the 7th IFAC (International Federation of Automatic Control) Symposium on Modelling and Control in Biomedical Systems (including Biological Systems) that was held in Aalborg, Denmark in 2009. This interdisciplinary forum brought together experts with backgrounds in mathematics, engineering, physiology and the clinical sciences with particular interest in the mathematical modelling and control. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5321995 Sun, 16 Oct 2011 18:10:43 +0100 5321995 http://www.medworm.com/index.php?rid=5321994&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002367%2Fabstract%3Frss%3Dyes (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5321994 Sun, 16 Oct 2011 18:10:43 +0100 5321994 http://www.medworm.com/index.php?rid=5204980&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002683%2Fabstract%3Frss%3Dyes Abstract: The paper presents an overview of the 15 year long development of fetal phonocardiography including the works on the applied signal processing methods for identification of sound components. Based on the improvements achieved on this field, the paper shows that beyond the traditional CTG test the phonocardiography may be successfully applied for long-term fetal measurements and home monitoring. In addition, by indication of heart murmurs based on a comprehensive analysis of the recorded heart sound congenital heart defects can also be detected together with additional features in the third trimester. This makes an early widespread screening possible combined with the prescribed CTG test even at home using a telemedicine system. (Source: Computer Methods and Programs in Biomedicin... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5204980 Sun, 11 Sep 2011 05:29:30 +0100 5204980 http://www.medworm.com/index.php?rid=5204979&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002026%2Fabstract%3Frss%3Dyes This article describes version 2.1 of this website and shows illustration on five different real examples. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5204979 Sun, 11 Sep 2011 05:29:30 +0100 5204979 http://www.medworm.com/index.php?rid=5204978&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001781%2Fabstract%3Frss%3Dyes Abstract: In this paper we propose a new structure of the instrumentation for electrocardiographic fetal monitoring. We apply a single-channel approach to maternal electrocardiogram suppression in the recorded four abdominal bioelectric signals. Then we exploit spatial and temporal properties of the extracted four-channel fetal electrocardiogram to construct a new channel with higher signal-to-noise ratio. Finally, we perform detection of fetal QRS complexes. The proposed approach is investigated with the help of the constructed database of the maternal abdominal signals. During the detection tests, the spatio-temporal filtering allowed us to decrease significantly the number of the detection errors of different detectors applied. Moreover, we present visually that even if the fetal QRS co... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5204978 Sun, 11 Sep 2011 05:29:30 +0100 5204978 http://www.medworm.com/index.php?rid=5204977&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711002124%2Fabstract%3Frss%3Dyes (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5204977 Sun, 11 Sep 2011 05:29:30 +0100 5204977 http://www.medworm.com/index.php?rid=5048979&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS016926071000266X%2Fabstract%3Frss%3Dyes We report the development of a computer system for long-term large-scale recording and storage of multichannel physiologic signals that was built using commercial solutions (software and hardware) and existing hospital IT infrastructure. Both numeric (1Hz) and waveform (62.5–500Hz) data were captured from 24 SICU bedside monitors simultaneously and stored in a file-based vital sign data bank (VSDB) during one-year period (total DB size is 4.21TB). In total, vital signs were recorded from 1175 critically ill patients. Up to six ECG leads, all other monitored waveforms, and all monitored numeric data were recorded in most of the cases.We describe the details of building blocks of our system, provide description of three datasets exported from our VSDB and compare the contents of our VSDB w... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5048979 Fri, 22 Jul 2011 00:47:22 +0100 5048979 http://www.medworm.com/index.php?rid=5048978&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001951%2Fabstract%3Frss%3Dyes The objective of this study was to develop an online automatic DRLs management system for digital radiography (DR) with the aim of addressing the challenges of the DRLs obligation.An online automatic DRLs management system for DR composed of freeware was developed. The system was tested with 75 DR images. This pilot experience shows that the system successfully addresses the challenges in the DRLs management, i.e. resource demand for running the audit cycle by individual imaging departments and availability of DRLs. It can provide at a low cost an efficient and effective solution to the implementation of regular audits of patient doses using DR in busy clinical departments. It can also contribute to the development of DRLs at local and national levels. In this way, any unacceptable radiolo... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5048978 Fri, 22 Jul 2011 00:47:21 +0100 5048978 http://www.medworm.com/index.php?rid=5048977&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001665%2Fabstract%3Frss%3Dyes Abstract: The purpose of this research is to develop an algorithm for a feedback controlled local electrical nerve fiber stimulation system which has the purpose to stop the repetitive firing in a particular region of the nervous system. The electrophysiological behavior of the neurons (under electrical currents) is modeled by Hodgkin–Huxley (HH) type nonlinear nerve fiber dynamics. The repetitive firing of in the modeled fiber is due to the deviations in the channel parameters, which is also called as bifurcation in the nonlinear systems theory. A washout filter is augmented to the HH dynamics and then the output of the filter is fed to the external current generator through a linear gain. This gain is computed by linear projective control theory. That is a linear output feedback contro... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5048977 Fri, 22 Jul 2011 00:47:21 +0100 5048977 http://www.medworm.com/index.php?rid=5048976&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001677%2Fabstract%3Frss%3Dyes Abstract: This paper proposes the assessment of bilateral photoplethysmography (PPG) for lower limb peripheral vascular occlusive disease (PVOD) using a color relation analysis (CRA) classifier. PPG signals are non-invasively recorded from the right and left sides at the big toe sites. With the time-domain technique, the right-to-left side difference is studied by comparing the subject's PPG data. The absolute bilateral differences construct various diminishing and damping patterns. These difference patterns in amplitude and shape distortion relate to the grades of PVOD, including the normal condition, lower-grade disease, and higher-grade disease. A CRA classifier is used to recognize the various patterns for PVOD assessment. Its concept is derived from the HSV color model and uses the hu... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5048976 Fri, 22 Jul 2011 00:47:21 +0100 5048976 http://www.medworm.com/index.php?rid=5048975&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS016926071000163X%2Fabstract%3Frss%3Dyes Abstract: Dual-axis cervical accelerometry is an emerging approach for the assessment of swallowing difficulties. However, the baseline signals, i.e., vibration signals with only quiet breathing or apnea but without swallowing, are not well understood. In particular, to comprehend the contaminant effects of head motion on cervical accelerometry, we need to study the scaling behavior of these baseline signals. Dual-axis accelerometry data were collected from 50 healthy adult participants under conditions of quiet breathing, apnea and selected head motions, all in the absence of swallowing. The denoised cervical vibrations were subjected to detrended fluctuation analysis with empirically determined first-order detrending. Strong persistence was identified in cervical vibration signals in bot... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5048975 Fri, 22 Jul 2011 00:47:21 +0100 5048975 http://www.medworm.com/index.php?rid=5048974&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711001763%2Fabstract%3Frss%3Dyes (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=5048974 Fri, 22 Jul 2011 00:47:21 +0100 5048974 http://www.medworm.com/index.php?rid=4975065&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002257%2Fabstract%3Frss%3Dyes Abstract: Local motion within intra-patient biomedical images can be compensated by using elastic image registration. The application of B-spline based elastic registration during interventional treatment is seriously hampered by its considerable computation time. The graphics processing unit (GPU) can be used to accelerate the calculation of such elastic registrations by using its parallel processing power, and by employing the hardwired tri-linear interpolation capabilities in order to efficiently perform the cubic B-spline evaluation. In this article it is shown that the similarity measure and its derivatives also can be calculated on the GPU, using a two pass approach. On average a speedup factor 50 compared to a straight-forward CPU implementation was reached. (Source: Computer Method... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4975065 Tue, 28 Jun 2011 20:26:49 +0100 4975065 http://www.medworm.com/index.php?rid=4975064&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS016926071000194X%2Fabstract%3Frss%3Dyes Abstract: CAIMAN (CAncer IMage ANalysis: http://www.caiman.org.uk) is an online algorithm repository that provides specifically designed algorithms to analyse the images produced by experiments relevant to Cancer Research and Life Sciences, especially vascular biology. CAIMAN is accessed through a user-friendly website where researchers can upload their images and the results are returned by email. CAIMAN does not intend to replace more sophisticated software solutions such as ImageJ, Matlab, or commercial packages, but it will provide a first stop where any researcher can upload images and can obtain quantitative results without having to do any programming at all. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4975064 Tue, 28 Jun 2011 20:26:48 +0100 4975064 http://www.medworm.com/index.php?rid=4975063&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001471%2Fabstract%3Frss%3Dyes Conclusions: IDD Info is a practical and accurate means of managing the multifarious IDD surveillance data that can be widely used by non-statisticians in national and regional IDD surveillance. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4975063 Tue, 28 Jun 2011 20:26:48 +0100 4975063 http://www.medworm.com/index.php?rid=4975062&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001641%2Fabstract%3Frss%3Dyes In this study, DWI images are preprocessed and exponential apparent diffusion coefficient (eADC) images are produced. The eADC images are later brain extracted and normalized to a standard brain template. Subsequently, we utilized wavelets to denoise the eADC images. The images are rectified, thresholded and now conspicuous abnormal regions are subsequently identified utilizing different brain atlases. Abnormal regions constitute the features that will be used by a fuzzy relational classifier in order to categorize the diseases. A sensitivity and specificity of 60% and 93.33%, respectively, in detecting metabolic brain diseases have been achieved. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4975062 Tue, 28 Jun 2011 20:26:48 +0100 4975062 http://www.medworm.com/index.php?rid=4975061&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001525%2Fabstract%3Frss%3Dyes Abstract: Non-carious cervical lesions are characterized by the loss of dental hard tissue at the cement–enamel junction (CEJ). Exceeding stresses are therefore generated in the cervical region of the tooth that cause disruption of the bonds between the hydroxyapatite crystals, leading to crack formation and eventual loss of enamel and the underlying dentine.Damage identification was performed by image analysis techniques and allowed to quantitatively assess changes in teeth. A computerized two-step procedure was generated and applied to the first left maxillary human premolar. In the first step, dental images were digitally processed by a segmentation method in order to identify the damage. The considered morphological properties were the enamel thickness and total area, the number of f... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4975061 Tue, 28 Jun 2011 20:26:48 +0100 4975061 http://www.medworm.com/index.php?rid=4975060&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711001593%2Fabstract%3Frss%3Dyes (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4975060 Tue, 28 Jun 2011 20:26:48 +0100 4975060 http://www.medworm.com/index.php?rid=4920526&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001756%2Fabstract%3Frss%3Dyes Abstract: When the maximum likelihood approach (ML) is used during the calculation of the Discrete Hidden Markov Model (DHMM) parameters, DHMM parameters of the each class are only calculated using the training samples (positive training samples) of the same class. The training samples (negative training samples) not belonging to that class are not used in the calculation of DHMM model parameters. With the aim of supplying that deficiency, by involving the training samples of all classes in calculating processes, a Rocchio algorithm based approach is suggested. During the calculation period, in order to determine the most appropriate values of parameters for adjusting the relative effect of the positive and negative training samples, a Genetic algorithm is used as an optimization technique... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4920526 Sat, 11 Jun 2011 03:29:31 +0100 4920526 http://www.medworm.com/index.php?rid=4920525&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001458%2Fabstract%3Frss%3Dyes Abstract: In this paper we describe a software package for developing heart rate variability analysis. This package, called RHRV, is a third party extension for the open source statistical environment R, and can be freely downloaded from the R-CRAN repository. We review the state of the art of software related to the analysis of heart rate variability (HRV). Based upon this review, we motivate the development of an open source software platform which can be used for developing new algorithms for studying HRV or for performing clinical experiments. In particular, we show how the RHRV package greatly simplifies and accelerates the work of the computer scientist or medical specialist in the HRV field. We illustrate the utility of our package with practical examples. (Source: Computer Methods ... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4920525 Sat, 11 Jun 2011 03:29:31 +0100 4920525 http://www.medworm.com/index.php?rid=4920524&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001446%2Fabstract%3Frss%3Dyes Abstract: Analysis of retinal vessel tree characteristics is an important task in medical diagnosis, specially in cases of diseases like vessel occlusion, hypertension or diabetes. The detection and classification of feature points in the arteriovenous eye tree will increase the information about the structure allowing its use for medical diagnosis. In this work a method for detection and classification of retinal vessel tree feature points is presented. The method applies and combines imaging techniques such as filters or morphologic operations to obtain an adequate structure for the detection. Classification is performed by analysing the feature points environment. Detection and classification of feature points is validated using the VARIA database. Experimental results are compared to p... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4920524 Sat, 11 Jun 2011 03:29:31 +0100 4920524 http://www.medworm.com/index.php?rid=4920523&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS016926071000146X%2Fabstract%3Frss%3Dyes This study attempts to do a case comparison of the fuzzy and AHP methods in the development of medical diagnosis system, which involves basic symptoms elicitation and analysis. The results of the study indicate a non-statistically significant relative superiority of the fuzzy technology over the AHP technology. Data collected from 30 malaria patients were used to diagnose using AHP and fuzzy logic independent of one another. The results were compared and found to covary strongly. It was also discovered from the results of fuzzy logic diagnosis covary a little bit more strongly to the conventional diagnosis results than that of AHP. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4920523 Sat, 11 Jun 2011 03:29:31 +0100 4920523 http://www.medworm.com/index.php?rid=4920522&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001239%2Fabstract%3Frss%3Dyes Abstract: We analyze the effect of electrode mislocation on the electroencephalography (EEG) inverse problem using the Cramér–Rao bound (CRB) for single dipolar source parameters. We adopt a realistic head shape model, and solve the forward problem using the Boundary Element Method; the use of the CRB allows us to obtain general results which do not depend on the algorithm used for solving the inverse problem. We consider two possible causes for the electrode mislocation, errors in the measurement of the electrode positions and an imperfect registration between the electrodes and the scalp surfaces. For 120 electrodes placed in the scalp according to the 10–20 standard, and errors on the electrode location with a standard deviation of 5mm, the lower bound on the standard deviation in ... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4920522 Sat, 11 Jun 2011 03:29:31 +0100 4920522 http://www.medworm.com/index.php?rid=4920521&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711001465%2Fabstract%3Frss%3Dyes (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4920521 Sat, 11 Jun 2011 03:29:31 +0100 4920521 http://www.medworm.com/index.php?rid=4801819&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001422%2Fabstract%3Frss%3Dyes Abstract: Proton therapy is a type of particle therapy which utilizes a beam of protons to irradiate diseased tissue. The main difference with respect to conventional radiotherapy (X-rays, γ-rays) is the capability to target tumors with extreme precision, which makes it possible to treat deep-seated tumors and tumors affecting noble tissues as brain, eyes, etc. However, proton therapy needs high-energy cyclotrons and this requires sophisticated control-supervision schema to guarantee, further than the prescribed performance, the safety of the patients and of the operators. In this paper we present the modeling and simulation of the irradiation process of the PROSCAN facility at the Paul Scherrer Institut. This is a challenging task because of the complexity of the operation scenario, whic... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4801819 Mon, 09 May 2011 23:50:41 +0100 4801819 http://www.medworm.com/index.php?rid=4801818&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS016926071000115X%2Fabstract%3Frss%3Dyes Abstract: Guyton’s original integrative physiology model was a milestone in integrative physiology, combining significant physiological knowledge with an engineering perspective to develop a computational diagrammatic model. It is still used in research and teaching, with a small number of variants on the model also in circulation. However, though new research has added significantly to the knowledge represented by Guyton’s model, and significant advances have been made in computing and simulation software, an accepted common platform to integrate this new knowledge has not emerged. This paper discusses the issues in the selection of a suitable platform, together with a number of current possibilities, and suggests a graphical computing environment for modelling and simulation. By way ... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4801818 Mon, 09 May 2011 23:50:40 +0100 4801818 http://www.medworm.com/index.php?rid=4801817&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001252%2Fabstract%3Frss%3Dyes Abstract: The Institute of Medicine has identified both computerized physician order entry and electronic prescription as keys to reducing medication errors and improving safety. Many computerized clinical decision support systems can enhance practitioner performance. However, the development of such systems involves a long cycle time that makes it difficult to apply them on a wider scale. This paper presents a suite of guideline modeling and execution tools, built on Protégé, Jess and Java technologies, which are easy to use, and also capable of automatically synthesizing clinical decision support systems for clinical practice guidelines of moderate complexity. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4801817 Mon, 09 May 2011 23:50:40 +0100 4801817 http://www.medworm.com/index.php?rid=4801816&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001197%2Fabstract%3Frss%3Dyes In this study, a software program was developed for high-frequency hearing loss subjects that includes a detailed audiogram and novel enhancement methods. The software performs enhancements of the audibility of high-frequency sounds according to the subject's detailed 31-point audiogram. This provides subject-specific gains in the entire frequency spectrum, and especially for high frequencies, of sounds. Amplification, compression, and transposition are the three main processing methods used to obtain the desired enhancements for the subjects. For low frequencies, only the amplification method was used according to the dB value of the input. For mid and high frequencies, the compression and transposition methods were used together. To obtain the preliminary results of the study, 10 subject... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4801816 Mon, 09 May 2011 23:50:39 +0100 4801816 http://www.medworm.com/index.php?rid=4801815&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001173%2Fabstract%3Frss%3Dyes Abstract: Systems engineering aims to produce reliable systems which function according to specification. In this paper we follow a systems engineering approach to design a biomedical signal processing system. We discuss requirements capturing, specification definition, implementation and testing of a classification system. These steps are executed as formal as possible. The requirements, which motivate the system design, are based on diabetes research. The main requirement for the classification system is to be a reliable component of a machine which controls diabetes. Reliability is very important, because uncontrolled diabetes may lead to hyperglycaemia (raised blood sugar) and over a period of time may cause serious damage to many of the body systems, especially the nerves and blood ve... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4801815 Mon, 09 May 2011 23:50:39 +0100 4801815 http://www.medworm.com/index.php?rid=4801814&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001215%2Fabstract%3Frss%3Dyes Conclusions: The model accurately captures and predicts the fundamental dynamic behaviors of the neonatal metabolism well enough for effective clinical decision support in glycemic control. The adaptation from adult to a neonatal case is based on the data from the literature. Low prediction errors and very low fitting errors indicate that the fundamental dynamics of glucose metabolism in both premature neonates and critical care adults can be described by similar mathematical models. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4801814 Mon, 09 May 2011 23:50:38 +0100 4801814 http://www.medworm.com/index.php?rid=4801813&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001185%2Fabstract%3Frss%3Dyes Abstract: Bayesian approaches have been proposed by several functional magnetic resonance imaging (fMRI) researchers in order to overcome the fundamental limitations of the popular statistical parametric mapping method. However, the difficulties associated with subjective prior elicitation have prevented the widespread adoption of the Bayesian methodology by the neuroimaging community. In this paper, we present a Bayesian multilevel model for the analysis of brain fMRI data. The main idea is to consider that all the estimated group effects (fMRI activation patterns) are exchangeable. This means that all the collected voxel time series are considered manifestations of a few common underlying phenomena. In contradistinction to other Bayesian approaches, we think of the estimated activations ... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4801813 Mon, 09 May 2011 23:50:38 +0100 4801813 http://www.medworm.com/index.php?rid=4801812&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001148%2Fabstract%3Frss%3Dyes Abstract: The introduction of integrative approaches to biomedical research (integrative biology, physiome, Virtual Physiological Human, etc.) poses original problems to computer aided medicine: the need to operate with large amounts of data that are strongly heterogeneous in structure, format and even in the knowledge domain that generated them; the need to integrate all of these data into a coherent whole; the further complication imposed by the fact that more and more frequently these data are captured at very different dimensional and/or temporal scales. The present study describes a first attempt at providing an interactive visualisation environment for homogeneous biomedical data defined over radically different spatial or temporal scales. In particular, we describe new strategies fo... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4801812 Mon, 09 May 2011 23:50:37 +0100 4801812 http://www.medworm.com/index.php?rid=4801811&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS016926071100112X%2Fabstract%3Frss%3Dyes (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4801811 Mon, 09 May 2011 23:50:37 +0100 4801811 http://www.medworm.com/index.php?rid=4747231&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS016926071000060X%2Fabstract%3Frss%3Dyes Abstract: Contrast-enhanced ultrasound (CEU) is an ultrasound imaging technique used to assess tissue perfusion. Analysis of microvascular recruitment necessitates the definition of a region of interest (ROI) containing exclusively the tissues to be studied. Conventional ROI selection requires examining the images and drawing the ROI by hand, making the analysis of CEU images non-reproducible and analyst-dependent. We have designed a systematic ROI selection method that is both reproducible and analyst-independent. Microvascular blood volume (MBV) assessed in 21 sequences of images was used to correlate the systematic ROI selection method with the conventional method performed by two independent analysts (correlation of 0.88 and 0.87 respectively) and the MBV sample distribution from the s... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4747231 Mon, 25 Apr 2011 14:26:56 +0100 4747231 http://www.medworm.com/index.php?rid=4747230&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001434%2Fabstract%3Frss%3Dyes Abstract: The model-based Karlsburg Diabetes Management System (KADIS®) has been developed as a patient-focused decision-support tool to provide evidence-based advice for physicians in their daily efforts to optimize metabolic control in diabetes care of their patients on an individualized basis. For this purpose, KADIS® was established in terms of a personalized, interactive in silico simulation procedure, implemented into a problem-related diabetes health care network and evaluated under different conditions by conducting open-label mono- and polycentric trials, and a case–control study, and last but not least, by application in routine diabetes outpatient care. The trial outcomes clearly show that the recommendations provided to the physicians by KADIS® lead to significant improvem... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4747230 Mon, 25 Apr 2011 14:26:56 +0100 4747230 http://www.medworm.com/index.php?rid=4747229&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710003007%2Fabstract%3Frss%3Dyes This article also contains significant reference to relevant physiology and clinical literature, as well as some references to the modeling efforts in this field.Identification of critical constant population parameters was performed in two stages, thus addressing model identifiability issues. Model predictive performance is the primary factor for optimizing population parameter values. The use of population values are necessary due to the limited clinical data available at the bedside in the clinical control scenario. Insulin sensitivity, SI, the only dynamic, time-varying parameter, is identified hourly for each individual. All population parameters are justified physiologically and with respect to values reported in the clinical literature. A parameter sensitivity study confirms the val... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4747229 Mon, 25 Apr 2011 14:26:56 +0100 4747229 http://www.medworm.com/index.php?rid=4747228&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710000623%2Fabstract%3Frss%3Dyes This study presents the development of a model-based stochastic targeted controller designed to adapt insulin infusion rates to match the unique and changing metabolic state and control parameters of the neonate. Long-term usage of targeted BG control requires successfully forecasting variations in neonatal metabolic state, accounting for differences in clinical practices between units, and demonstrating robustness to errors that can occur in everyday clinical usage. Simulation studies were used to evaluate controller ability to target several common BG ranges and evaluate controller sensitivity to missed BG measurements and delays in control interventions on a virtual patient cohort of 25 infants developed from retrospective data. Initial clinical pilot trials indicated model performance ... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4747228 Mon, 25 Apr 2011 14:26:55 +0100 4747228 http://www.medworm.com/index.php?rid=4747227&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002038%2Fabstract%3Frss%3Dyes Abstract: Glucocorticoids (GCs) have been shown to reduce insulin sensitivity in healthy individuals. Widely used in critical care to treat a variety of inflammatory and allergic disorders, they may inadvertently exacerbate stress-hyperglycaemia. This research uses model-based methods to quantify the reduction in insulin sensitivity from GCs in critically ill patients, and thus their impact on glycaemic control. A model-based measure of insulin sensitivity (SI) was used to quantify changes between two matched cohorts of 40 intensive care unit (ICU) patients. Patients in one cohort received GC treatment, while patients in the control cohort did not. All patients were admitted to the Christchurch hospital ICU between 2005 and 2007 and spent at least 24h on the SPRINT glycaemic control protoc... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4747227 Mon, 25 Apr 2011 14:26:55 +0100 4747227 http://www.medworm.com/index.php?rid=4747226&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002828%2Fabstract%3Frss%3Dyes Abstract: Tight glycemic control (TGC) has emerged as a major research focus in critical care due to its potential to simultaneously reduce both mortality and costs. However, repeating initial successful TGC trials that reduced mortality and other outcomes has proven difficult with more failures than successes. Hence, there has been growing debate over the necessity of TGC, its goals, the risk of severe hypoglycemia, and target cohorts.This paper provides a review of TGC via new analyses of data from several clinical trials, including SPRINT, Glucontrol and a recent NICU study. It thus provides both a review of the problem and major background factors driving it, as well as a novel model-based analysis designed to examine these dynamics from a new perspective. Using these clinical results ... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4747226 Mon, 25 Apr 2011 14:26:54 +0100 4747226 http://www.medworm.com/index.php?rid=4747225&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710000878%2Fabstract%3Frss%3Dyes Abstract: Sepsis occurs frequently in the intensive care unit (ICU) and is a leading cause of admission, mortality, and cost. Treatment guidelines recommend early intervention, however positive blood culture results may take up to 48h. Insulin sensitivity (SI) is known to decrease with worsening condition and could thus be used to aid diagnosis. Some glycemic control protocols are able to accurately identify insulin sensitivity in real-time.Hourly model-based insulin sensitivity SI values were calculated from glycemic control data of 36 patients with sepsis. The hourly SI is compared to the hourly sepsis score (ss) for these patients (ss=0–4 for increasing severity). A multivariate clinical biomarker was also developed to maximize the discrimination between different ss groups. Receiver ... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4747225 Mon, 25 Apr 2011 14:26:54 +0100 4747225 http://www.medworm.com/index.php?rid=4747224&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001082%2Fabstract%3Frss%3Dyes Abstract: Automatic control of Type 1 Diabetes Mellitus (T1DM) with subcutaneous (SC) measurement of glucose concentration and subcutaneous (SC) insulin infusion is of great interest within the diabetes technology research community. The main challenge with the so-called “SC–SC” route to control is sensing and actuation delay, which tends to either destabilize the system or inhibit the aggressiveness of the controller in responding to meals and exercise. Model predictive control (MPC) is one strategy for mitigating delay, where optimal insulin infusions can be given in anticipation of future meal disturbances. Unfortunately, exact prior knowledge of meals can only be assured in a clinical environment and uncertainty about when and if meals will arrive could lead to catastrophic outco... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4747224 Mon, 25 Apr 2011 14:26:53 +0100 4747224 http://www.medworm.com/index.php?rid=4747223&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001501%2Fabstract%3Frss%3Dyes Abstract: Individuals with type 1 diabetes mellitus must effectively manage glycemia to avoid acute and chronic complications related to aberrations of glucose levels. Because optimal diabetes management can be difficult to achieve and burdensome, research into a closed-loop insulin delivery system has been of interest for several decades. This paper provides an overview, from a control systems perspective, of the research and development effort of a particular algorithm—the external physiologic insulin delivery system. In particular the introduction of insulin feedback, based on β-cell physiology, is covered in detail. A summary of human clinical trials is provided in the context of the evolution of this algorithm, and this paper outlines some of the research avenues that show particul... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4747223 Mon, 25 Apr 2011 14:26:53 +0100 4747223 http://www.medworm.com/index.php?rid=4747222&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002245%2Fabstract%3Frss%3Dyes Abstract: The glucose–insulin system is a challenging process to model due to the feedback mechanisms present, hence the implementation of a model-based approach to the system is an on-going and challenging research area. A new approach is proposed here which provides an effective way of characterising glycaemic regulation. The resulting model is built on the premise that there are three phases of insulin secretion, similar to those seen in a proportional-integral-derivative (PID) type controller used in engineering control problems. The model relates these three phases to a biological understanding of the system, as well as the logical premise that the homeostatic mechanisms will maintain very tight control of the system. It includes states for insulin, glucose, insulin action and a sta... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4747222 Mon, 25 Apr 2011 14:26:52 +0100 4747222 http://www.medworm.com/index.php?rid=4747221&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001720%2Fabstract%3Frss%3Dyes Abstract: Using induced L2-norm minimization, a robust controller was developed for insulin delivery in Type I diabetic patients. The high-complexity nonlinear diabetic patient Sorensen-model was considered and Linear Parameter Varying methodology was used to develop open-loop model and robust H∞ controller. Considering the normoglycaemic set point (81.1mg/dL), a polytopic set was created over the physiologic boundaries of the glucose–insulin interaction of the Sorensen-model. In this way, Linear Parameter Varying model formalism was defined. The robust control was developed considering input and output multiplicative uncertainties with two additional uncertainties from those used in the literature: sensor noise and worst-case design for meal disturbance (60g carbohydrate). Simulation ... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4747221 Mon, 25 Apr 2011 14:26:52 +0100 4747221 http://www.medworm.com/index.php?rid=4747220&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002014%2Fabstract%3Frss%3Dyes Abstract: Insulin sensitivity (SI) is useful in the diagnosis, screening and treatment of diabetes. However, most current tests cannot provide an accurate, immediate or real-time estimate. The DISTq method does not require insulin or C-peptide assays like most SI tests, thus enabling real-time, low-cost SI estimation. The method uses a posteriori parameter estimations in the absence of insulin or C-peptide assays to simulate accurate, patient-specific, insulin concentrations that enable SI identification.Mathematical functions for the a posteriori parameter estimates were generated using data from 46 fully sampled DIST tests (glucose, insulin and C-peptide). SI values found using the DISTq from the 46 test pilot cohort and a second independent 218 test cohort correlated R=0.890 and R=0.825... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4747220 Mon, 25 Apr 2011 14:26:51 +0100 4747220 http://www.medworm.com/index.php?rid=4747219&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710003160%2Fabstract%3Frss%3Dyes The mathematical modelling of blood glucose and its control systems is a subject that has a history of well over 50 years. In the early days models were devised in order to aid understand of the regulatory processes in quantitative terms. As the methodology for modelling has evolved, complemented by advances in computational technology, we have reached a stage where models not only aid physiological understanding but are also finding significant clinical application. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4747219 Mon, 25 Apr 2011 14:26:51 +0100 4747219 http://www.medworm.com/index.php?rid=4747218&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000873%2Fabstract%3Frss%3Dyes (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4747218 Mon, 25 Apr 2011 14:26:51 +0100 4747218 http://www.medworm.com/index.php?rid=4591093&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002762%2Fabstract%3Frss%3Dyes Abstract: Aspiration reflex (AspR) represents a specific inspiratory motor behavior expressed by short, powerful inspiratory activity without subsequent active expiration and characterized by the ability to interrupt strong tonic inspiratory activity, as well as hypoxic apnea and several other functional disorders. Multiresolution analysis-based determination of spectral features arising during AspR has not yet been satisfactorily investigated.The time–frequency energy distribution of phrenic nerve electrical activity was compared during the AspR, inspiratory phase of tracheobronchial cough and quiet inspiration. Data obtained from 16 adult cats anesthetized with chloralose or pentobarbital were analyzed using a wavelet transformation, a sensitive method suitable for processing of the no... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4591093 Tue, 15 Mar 2011 22:49:05 +0100 4591093 http://www.medworm.com/index.php?rid=4591092&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002786%2Fabstract%3Frss%3Dyes Abstract: The Kruskal–Wallis (KW) nonparametric analysis of variance is often used instead of a standard one-way ANOVA when data are from a suspected non-normal population. The KW omnibus procedure tests for some differences between groups, but provides no specific post hoc pair wise comparisons. This paper provides a SAS® macro implementation of a multiple comparison test based on significant Kruskal–Wallis results from the SAS NPAR1WAY procedure. The implementation is designed for up to 20 groups at a user-specified alpha significance level. A Monte-Carlo simulation compared this nonparametric procedure to commonly used parametric multiple comparison tests. (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4591092 Tue, 15 Mar 2011 22:49:05 +0100 4591092 http://www.medworm.com/index.php?rid=4591091&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002853%2Fabstract%3Frss%3Dyes Abstract: Most dental implant planning systems use a 3D representation of the CT scan of the patient under study as it provides a more intuitive view of the human jaw. The presence of metallic objects in human jaws, such as amalgam or gold fillings, provokes several artifacts like streaking and beam hardening which makes the reconstruction process difficult. In order to reduce these artifacts, several methods have been proposed using the raw data, directly obtained from the tomographs, in different ways. However, in DICOM-based applications this information is not available, and thus the need of a new method that handles this task in the DICOM domain. The presented method performs a morphological filtering in the polar domain yielding output images less affected by artifacts (even in cases... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4591091 Tue, 15 Mar 2011 22:49:05 +0100 4591091 http://www.medworm.com/index.php?rid=4591090&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002944%2Fabstract%3Frss%3Dyes Abstract: This paper presents a fully automated segmentation and classification scheme for mammograms, based on breast density estimation and detection of asymmetry. First, image preprocessing and segmentation techniques are applied, including a breast boundary extraction algorithm and an improved version of a pectoral muscle segmentation scheme. Features for breast density categorization are extracted, including a new fractal dimension-related feature, and support vector machines (SVMs) are employed for classification, achieving accuracy of up to 85.7%. Most of these properties are used to extract a new set of statistical features for each breast; the differences among these feature values from the two images of each pair of mammograms are used to detect breast asymmetry, using an one-cla... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4591090 Tue, 15 Mar 2011 22:49:04 +0100 4591090 http://www.medworm.com/index.php?rid=4591089&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710003019%2Fabstract%3Frss%3Dyes Abstract: The paper presents a method of development of a detailed network model to represent retinal capillary vasculature. The capillary model is a circular mesh consisting of concentric rings with an increasing diameter. Each of the rings has uniformly distributed bifurcation nodes to represent capillary vessels. The model is customized using the data that has been measured from confocal microscopic images of a mouse retina. The capillary model developed can be connected to networks of larger vessels of the vasculature such as arterial and venous networks to form a complete model of the retinal network. A method to automate such interface connections between capillary and other vascular networks using connecting vessels (i.e., pre-capillary and post-capillary) is also presented in the p... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4591089 Tue, 15 Mar 2011 22:49:04 +0100 4591089 http://www.medworm.com/index.php?rid=4591088&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710003147%2Fabstract%3Frss%3Dyes In this study, we show that feature values quantified on 2D sections are highly dependent on the orientation and the placement of the section, suggesting that a 3D analysis of the whole sample is of importance for a more complete judgment of the bone structure in the proximity of the implant. We propose features describing the 3D data by extending the features traditionally used for 2D-analysis. We present a method for extracting these features from 3D image data and we measure them on five 3D SRμCT image volumes.We also simulate cuts through the image volume positioned at all possible section positions. These simulations show that the measurement variations due to the orientation of the section around the center line of the implant are about 30%. (Source: Computer Methods and Programs in... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4591088 Tue, 15 Mar 2011 22:49:04 +0100 4591088 http://www.medworm.com/index.php?rid=4591087&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002890%2Fabstract%3Frss%3Dyes Abstract: In the course of 2 months, 25 repetitions of a 20min audio-visual stimulation (AVS) program with stimulations at 17, 9, 4, and 2Hz were applied to 6 volunteers. EEG data were recorded from 6 scalp locations prior, during and after AVS. In order to identify direct and transient changes in EEG under influence of AVS, total power, relative frequency band powers and magnitude-squared coherences were estimated. Intense brain wave entrainment as a direct reaction to AVS was significant through increase of spectral powers and coherences around the stimulating frequency bands in the occipital areas, spreading also to the central and frontal regions. However, these excitations were ‘short-lived’. On the other hand some signs of interhemispheric cooperation (coherences in the narrow ba... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4591087 Tue, 15 Mar 2011 22:49:04 +0100 4591087 http://www.medworm.com/index.php?rid=4591086&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710002919%2Fabstract%3Frss%3Dyes Abstract: Fluorescein angiography is an established technique for examining the functional integrity of the retinal microcirculation for early detection of changes due to retinopathy. This paper describes a new method for the registration of large Scanning Laser Ophthalmoscope sequences (SLO), where the patient has been injected with a fluorescent dye. This allows the measurement of parameters such as the arteriovenous passage time. Due to the long time needed to acquire these sequences, there will inevitably be eye movement, which must be corrected prior to the application of quantitative analysis. The algorithm described here combines mutual information-based registration and landmark-based registration. The former will allow the alignment of the darkest frames of the sequence, where the... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4591086 Tue, 15 Mar 2011 22:49:04 +0100 4591086 http://www.medworm.com/index.php?rid=4591085&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260711000496%2Fabstract%3Frss%3Dyes (Source: Computer Methods and Programs in Biomedicine) Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4591085 Tue, 15 Mar 2011 22:49:04 +0100 4591085 http://www.medworm.com/index.php?rid=4371052&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001124%2Fabstract%3Frss%3Dyes Abstract: A new algorithm is proposed for the semi-automatic segmentation of the near-end and the far-end adventitia boundary of the common carotid artery in ultrasound images. It uses the random sample consensus method to estimate the most significant cubic splines fitting the edge map of a longitudinal section. The consensus of the geometric model (a spline) is evaluated through a new gain function, which integrates the responses to different discriminating features of the carotid boundary: the proximity of the geometric model to any edge or to valley shaped edges; the consistency between the orientation of the normal to the geometric model and the intensity gradient; and the distance to a rough estimate of the lumen boundary.A set of 50 longitudinal B-mode images of the common carotid a... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4371052 Sat, 01 Jan 2011 00:00:00 +0100 4371052 http://www.medworm.com/index.php?rid=4371051&cid=s_35480_79_f&fid=35480&url=http%3A%2F%2Fwww.cmpbjournal.com%2Farticle%2FPIIS0169260710001793%2Fabstract%3Frss%3Dyes Abstract: The cumulative incidence function is commonly reported in studies with competing risks. The aim of this paper is to compute the treatment-specific cumulative incidence functions, adjusting for potentially imbalanced prognostic factors among treatment groups. The underlying regression model considered in this study is the proportional hazards model for a subdistribution function . We propose estimating the direct adjusted cumulative incidences for each treatment using the pooled samples as the reference population. We develop two SAS macros for estimating the direct adjusted cumulative incidence function for each treatment based on two regression models. One model assumes the constant subdistribution hazard ratios between the treatments and the alternative model allows each treatm... Computer Methods and Programs in Biomedicine journals http://www.medworm.com/rss/comments.php?id=4371051 Sat, 01 Jan 2011 00:00:00 +0100 4371051