SEARCH CONTENT

You are looking at 1 - 10 of 14,400 items :

  • Biomedical Engineering x
Clear All Modify Search
Models and Technologies in Cancer Research
Series: De Gruyter STEM
Chemical Design, Processing and Applications
Series: De Gruyter STEM
Series: Health Academy
Series: De Gruyter STEM
From Infancy to Young Adulthood

Abstract

Epilepsy is a persistent neurological disorder impacting over 50 million people around the world. It is characterized by repeated seizures defined as brief episodes of involuntary movement that might entail the human body. Electroencephalography (EEG) signals are usually used for the detection of epileptic seizures. This paper introduces a new feature extraction method for the classification of seizure and seizure-free EEG time segments. The proposed method relies on the empirical mode decomposition (EMD), statistics and autoregressive (AR) parameters. The EMD method decomposes an EEG time segment into a finite set of intrinsic mode functions (IMFs) from which statistical coefficients and autoregressive parameters are computed. Nevertheless, the calculated features could be of high dimension as the number of IMFs increases, the Student’s t-test and the Mann–Whitney U test were thus employed for features ranking in order to withdraw lower significant features. The obtained features have been used for the classification of seizure and seizure-free EEG signals by the application of a feed-forward multilayer perceptron neural network (MLPNN) classifier. Experimental results carried out on the EEG database provided by the University of Bonn, Germany, demonstrated the effectiveness of the proposed method which performance assessed by the classification accuracy (CA) is compared to other existing performances reported in the literature.

Abstract

In this paper, we attempt to answer the questions whether iris recognition task under the influence of diabetes would be more difficult and whether the effects of diabetes and individuals’ age are uncorrelated. We hypothesized that the health condition of volunteers plays an important role in the performance of the iris recognition system. To confirm the obtained results, we reported the distribution of usable area in each subgroup to have a more comprehensive analysis of diabetes effects. There is no conducted study to investigate for which age group (young or old) the diabetes effect is more acute on the biometric results. For this purpose, we created a new database containing 1,906 samples from 509 eyes. We applied the weighted adaptive Hough ellipsopolar transform technique and contrast-adjusted Hough transform for segmentation of iris texture, along with three different encoding algorithms. To test the hypothesis related to physiological aging effect, Welches’s t-test and Kolmogorov–Smirnov test have been used to study the age-dependency of diabetes mellitus influence on the reliability of our chosen iris recognition system. Our results give some general hints related to age effect on performance of biometric systems for people with diabetes.

Abstract

Medical laboratory accreditation becomes a trend to be trustable for diagnosis of diseases. It is always performed at regular intervals to assure competence of quality management systems (QMS) based on pre-defined standards. However, few attempts were carried out to assess the quality level of medical laboratory services. Moreover, there is no realistic study that classifies and makes analyses of laboratory performance based on a computational model. The purpose of this study was to develop an integrated system for medical laboratory accreditation that assesses QMS against ISO 15189. In addition, a deep analysis of factors that sustain accreditation was presented. The system started with establishing a core matrix that maps QMS elements with ISO 15189 clauses. Through this map, a questionnaire was developed to measure the performance. Therefore, score indices were calculated for the QMS. A fuzzy logic model was designed based on the calculated scores to classify medical laboratories according to their tendency for accreditation. Further, in case of failure of accreditation, cause-and-effect root analysis was done to realize the causes. Finally, cloud computing principles were employed to launch a web application in order to facilitate user interface with the proposed system. In verification, the system has been tested using a dataset of 12 medical laboratories in Egypt. Results have proved system robustness and consistency. Thus, the system is considered as a self-assessment tool that demonstrates points of weakness and strength.

Abstract

The aim of this study was to develop and compare techniques to increase the prediction accuracy of patient mortality and organ dysfunction in the Intensive Care Units (hereinafter ICU) of hospitals. Patient mortality was estimated with two models of artificial neural network (ANN)-backpropagation (BP) and simplified acute physiology score (SAPS). Organ dysfunction was predicted by coupled ANN self-organizing map (SOM) and logistic organ dysfunction score (LODS) method on the basis of patient conditions. Input dataset consisted of 36 features recorded for 4,000 patients in the ICU. An integrated response surface methodology (RSM) and genetic algorithm (GA) was developed to achieve the best topology of the ANN-BP model. Although mortality prediction of the best ANN-BP (MSE = 0.0036, AUC = 0.83, R2 = 0.81) was more accurate than that of the SAPS score model (MSE = 0.0056, AUC = 0.82, R2 = 0.78), the execution time of the former (=45 min) was longer than that of the latter (=20 min). Therefore, the principal component analysis (PCA) was used to reduce the input feature dimensions, which, in turn, reduced the execution time up to 50%. Data reduction also helped to increase the network accuracy up to 90%. The likelihood of organ dysfunction determined by coupled ANN and scoring method technique can be much more efficient than the LODS model alone because the SOM could successfully classify the patients in 64 classes. The primary patient classification plays a major role in increasing the efficiency of an estimator.

Abstract

The electroencephalogram (EEG) induced by steady-state visual evoked potential (SSVEP) will contain background noise. Most existing research on this problem uses signal-processing methods to enhance the EEG. The purpose of this paper is to explore another method that can be used to enhance the EEG. We creatively combined motion stimuli with light-flashing stimuli and designed a paradigm in which motion and light-flashing simultaneously will stimulate with the same frequency; this is called multi-source co-frequency stimulus. To avoid the direct stimulus of light-flashing in the human eye and ensure that the composite paradigm provided adequate comfort, the light-flashing pattern was presented in a ring form and the motion stimulus was presented in the center of that ring. Our hypothesis is that when the motion and the light-flashing are simultaneously stimulated with the same frequency, the EEG they induce will be superimposed in some way, and this will enhance the EEG. The multi-source co-frequency stimulus was found to achieve a higher signal-to-noise ratio (SNR), better accuracy, and a higher information transmission rate (ITR) than single stimulus. The experimental results showed that it is feasible to use the method proposed in this study to enhance the EEG.