WSEAS CONFERENCES. WSEAS, Unifying the Science

Main Page of the Journal                                                           Main Page of the WSEAS


 Volume 5,  2008
Print ISSN: 1109-9518
E-ISSN: 2224-2902








Issue 1, Volume 5, January 2008

Title of the Paper: Motor Control Information Extracted from Surface EMG as Muscle Force Estimation


Authors: Rok Istenic, Ales Holobar, Marco Gazzoni, Damjan Zazula

Abstract: The aim of this paper is to introduce an extension to a force estimation technique based on activity index and to compare it to two other muscle force estimation techniques that also use the motor control information on the same set of surface EMG signals. Our new method is called motor unit twitch force technique and the compared methods include motor unit action potential rate and activity index. The main difference of the three compared methods lies in the extraction of the motor control information from multi-channel surface EMG. Motor unit action potential rate and activity index measure global muscle activity as they represent the summation of innervation pulse trains of all active motor units, while twitch force technique decomposes the surface EMG and obtains the activity of all active individual motor units separately. This means a great improvement over activity index and motor unit action potential rate methods as both force regulation principles, i.e. motor unit recruitment and firing rate modulation can be observed. Surface EMG signals used in the experiment were recorded from biceps brachii muscle during elbow flexion on five subjects. Two-dimensional matrix of surface electrodes (13 rows by 5 columns) was applied. Isometric constant force contractions at three different force levels were performed, i.e. at 5, 10 and 30 % of maximal voluntary contraction. Torque produced at the elbow joint was measured simultaneously with surface EMG. The force estimation error of the methods was measured by root mean square error between the recorded and estimated force. Our new motor unit twitch force technique reduced the muscle force estimation error significantly, for 13% when compared to the motor unit action potential rate, and for 2% when compared to the activity index method.

Keywords: surface electromyography, muscle force estimation, EMG force relationship, MUAP rate, activity index, twitch force

Title of the Paper: Agreement between Multi-Layer Perceptron and a Compound Neural Network on ECG Diagnosis of Aatrioventricular Blocks


Authors: Salama Meghriche, Mohammed Boulemden, Amer Draa

Abstract: Artificial Neural Networks (ANN) are computer-based expert systems that have proved to be useful in pattern recognition tasks. ANN can be used in different phases of the decision-making process, from classification to diagnostic procedures. In this work, we develop two methods. The first one based on a compound neural network (CNN) composed of three different multilayer neural networks of the feed forward type, and the second one based on only a multi-layer perceptron (MLP). Such both of them have the capability to classify electrocardiograms (ECG) as normal or as carrying atrioventricular blocks (AVB). These networks were fed with same measurements from one lead of the ECG. A single output unit encodes the probability of AVB occurrences. The difference in performance between the two neural networks classifiers was measured as the difference in area under the receiver operating characteristic curves (ROC). The results show that the CNN and MLP have a good performance in detecting AVBs.

Keywords: Artificial neural networks, Biomedical data, Electrocardiogram (ECG), Medical diagnosis, Pattern recognition, Signal processing,

Issue 2, Volume 5, February 2008

Title of the Paper: Minimization of Tumor Volume and Endothelial Support for a System Describing Tumor Anti-Angiogenesis


Authors: Urszula Ledzewicz, Heinz Schattler

Abstract: Anti-angiogenic therapy is a novel treatment approach for cancer that aims at preventing a tumor from developing its own network of blood vessels that it needs for its supply of nutrients and thus indirectly inhibits the growth of the tumor. In this paper a mathematical model for anti-angiogenic treatment is analyzed as a 3- dimensional optimal control problem with the aim of minimizing a convex combination of tumor volume and endothelial support. The latter represents a measure for the size of the tumor’s vasculature. The results are compared with the solutions for the problem when only the tumor volume is minimized.

Keywords: Optimal control, singular controls, cancer treatments, tumor growth, anti-angiogenesis

Title of the Paper: Random Modeling of Population Dynamics with Uncertainty


Authors: Gilberto Gonzalez, Lucas Jodar, Rafael Villanueva, Fransisco Santonja

Abstract: Obesity is growing at an important rate in developed and developing countries and it is becoming a serious disease not only from the individual health point of view but also from the public socioeconomic one. In this paper it is studied the effect of uncertainty in the dynamics behavior of the overweight and obesity childhood populations. Since initial conditions and parameters appearing in a deterministic mathematical model of obesity population are subject to some degree of uncertainty, randomness in the differential equations are introduced in the initial conditions and in the most relevant parameter of the deterministic model. Additionally, in this work stochastic and random ordinary differential equations were used to study the randomness effect in the deterministic mathematical model of obesity population.
Monte Carlo simulations are performed assuming different distributions for the initial conditions and parameters of the model. Furthermore, confidence intervals and expected solutions of the random models are also obtained. To verify the consistence of the method, results are compared against numerical solutions of the deterministic mathematical model.

Keywords: Random differential equation, Population dynamics, Numerical simulation, Stochastic differential equation, Monte Carlo method.

Issue 3, Volume 5, March 2008

Title of the Paper: Minimizing the Set Up for ADL Monitoring through DTW Hierarchical Classification on Accelerometer Data


Authors: Rossana Muscillo, Silvia Conforto, Maurizio Schmid, Tommaso D’Alessio

Abstract: Systems for remote monitoring of motor activities in the elderly are becoming very popular in developed countries. In this context, recognition and classification of Activities of Daily Living (ADL) is a very important step that can open intriguing scenarios, especially if real-time techniques become available. The present work proposes a hierarchical classifier based on the Dynamic Time Warping (DTW) technique, applied on data recorded from a tri-axial accelerometer placed on the shin, to classify among different motor activities. The classifier was applied to the recognition of walking, climbing and descending stairs of five different subjects. After the calibration phase needed to extract the templates, the technique makes it possible to recognize activities by determining the distance between the signal input and a set of the previously defined templates. Signals coming from the three different channels are used in a hierarchical way, with three layers. The hierarchy has been set based on sorting channels by signal to noise ratio in descending order. The results show a classification with overall percentage of error less than 5%.

Keywords: Wearable sensors, Accelerometer, ADL , Dynamic Time Warping, Template, Classification

Title of the Paper: Comparison of Cluster Identification Methods for Selection of GO Terms related to Gene Clusters


Authors: Yoichi Yamada, Yuki Miyata, Masanori Higashihara, Kenji Satou

Abstract: The hierarchical clustering algorithm has frequently been applied to grouping genes sharing a certain characteristic from a microarray data set. Identification of clusters from a hierarchical cluster tree is generally conducted by cutting the tree at a certain level. In this method, the most parental clusters are identified as mutually correlated gene groups and their sibling clusters are ignored. However the sibling clusters have a possibility to show more significant GO term annotation than their parental clusters. To overcome this problem, Toronen developed a novel algorithm based on the calculation of each GO annotation in all the clusters that satisfy a threshold of correlation distance. However comparison of the algorithm and the general method has not been done enough yet. Therefore we compared the general method with Toronen
s proposed algorithm for identifying gene cluster-relevant GO terms. Moreover, we compared the hierarchical clustering with fuzzy k-means clustering which can group a object into more than one cluster and permit a object not to belong to any clusters. Consequently, we confirmed that Toronens algorithm is more available for identification of gene clusters and their relevant GO terms from a microarray data set than the other methods.

Keywords: Hierarchical clustering, Gene Ontology, Microarray data, Yeast cell cycle

Issue 4, Volume 5, April 2008

Title of the Paper: Stabilizing Effect of Prey Competition for Predators Exhibiting Switching Feeding Behavior


Authors: Valerio Ajraldi, Ezio Venturino

Abstract: The classical model by Tanksy on a two-level food web with a predator feeding on two kinds of prey is revisited and extended. The ecosystem with intraspecific and interspecific competition for resources among the prey is analized. Two equilibria are found: a segment of conditionally (neutrally) stable equilibrium points and the interior coexistence equilibrium, which is proven to be inconditionally stable. The predator population settles to a lower level than the one arising in the original Tansky’s model. In addition, there is inverse proportionality between the predators’ mortality and the equilibrium value. Predators’ recovery and the settling of the system toward coexistence are also allowed by a large prey carrying capacity.

Keywords: Predator-prey, switching mechanism, Tansky model, competition, stable equilibria

Title of the Paper: Blood Glucose Data Processing for Automated Diagnosis


Authors: Eugen Iancu, Ionela Iancu, Maria Mota

Abstract: The actual protocols used in diagnosis and management of the diabetes mellitus include the classical clinical trials and the physicians’ experience, but they do not account by the dynamics of the blood glucose and insulin. So, it is natural to have many diabetes patients with poor control of blood glucose values. The introduction in the medical practice of the blood glucose continuous monitoring systems has made possible the automated analyse of blood glucose dynamics. Along this paper the authors present algorithms for automatic diagnosis in the diabetic patients monitoring with applications, especially in the intensive care units and telemedicine. We have focused on the statistical analysis methods in order to detect the reliable characteristics, useful in the identification of standard aspects or stable patterns for each type and stage of the complex and long-term evolution of the disease that is diabetes mellitus. Examples of the frequency range of blood glucose dynamics of normal subjects and subjects with diabetes are presented with the help of Wigner-Ville distribution. The spectral analysis reveals the frequency band edge and offers the basic information to correct determination of Nyquist sample period. These findings may have significant clinical implication in diagnosis of the diabetes mellitus, in blood glucose monitoring and the management of the diabetes therapy.

Keywords: Statistical analysis, Diabetes mellitus, Continuous glucose monitoring, Probability distribution function, Periodogram, Correlation

Issue 5, Volume 5, May 2008

Title of the Paper: Drug Resistants Impact on Tuberculosis Transmission


Authors: Silvia Martorano Raimundo, Ezio Venturino

Abstract: In epidemiology, measures for prophilaxis of infectious diseases are taken often using mathematical methods and statistical tools to evaluate possible future scenarios of the evolution of transmissible diseases. Here we present two models for TB transitions among different stages of the disease. We analyze them assuming to have a large basin of susceptible individuals available. The models account for immigration and demographic effects. A flow of infected members into the population is assumed. Part of it is made by a specified fraction is drug-sensitive latent individuals, while the other part consists of drug-resistant latent individuals. Our aim is the description and analysis of all the possible ways the infected individuals move. In particular, from the classes of latent to infectious, and possibly back upon successful treatment, or toward acute stages of the disease for drug resistant cases due to improper, incomplete or ineffective healing measures. Some conditions for the eradication of the disease are extracted from analytical considerations and simulation results and might be useful for epidemiological implementations.

Keywords: Drug resistant, transmissible disease, tuberculosis.

Title of the Paper: Application of a Feature Selection Method to Nucleosome Data: Accuracy Improvement and Comparison with Other Methods


Authors: Masanori Higashihara, Jovan David Rebolledo-Mendez, Yoichi Yamada, Kenji Satou

Abstract: In binary classification problem, data of feature vectors with binary labels are prepared in general. However, today it is well known that using all the features for discrimination does not always the best way to achieve the highest accuracy in prediction. Feature selection is a technique to find a subset of features with the highest accuracy by eliminating features harmful in prediction. Among various methods proposed, in this study we used a method which can be divided in two steps. Firstly, along the ranked features f1,…,fn based on Gini index, the feature subsets {f1},{f1,f2},...,{f1,…,fn} are tested by SVM with RBF kernel. Secondary, variants of the best feature subset found in the first step are tested in the same way. In the application to the prediction of nucleosome occupancy and modification from genome subsequence, the method achieved a small but assured improvement from the previous study. In addition, observed ranking of features revealed some relationships between features and categories of nucleosome datasets. Finally, the method was compared with other promising methods and outperformed them.

Keywords: Epigenetics, Histone, Acetylation, Methylation, Feature selection, Support vector machine, Gini-index, Random forest

Issue 6, Volume 5, June 2008

Title of the Paper: A Fractal Approach to Pattern Formation in Biological Systems


Authors: Radu Dobrescu, Loretta Ichim, Stefan Mocanu, Stefan Popa

Abstract: The paper discusses the connection between pattern formation and nonlinear dynamics, focusing on the similarity between discrete patterns and fractal structures, and then describes different solutions to model reaction-diffusion systems as representative processes in morphogenesis. The option for a discrete model and the steps to design it as a fractal structure is argued. Construction of appropriate generic model is an important step towards understanding the bacteria. It is shown how a pattern with arbitrary complexity like a fractal pattern can be realized by a reaction-diffusion system. A specific example is the diffusion limited aggregation growth process, illustrated by the simulation of the evolution of a bacterial colony that shows the roles of instability and sensitivity in nonequilibrium pattern formation.

Keywords: morphogenesis, pattern formation, reaction-diffusion systems, fractal analysis, attractors, diffusion limited aggregation

Title of the Paper: Stationary Densities and Parameter Estimation for Delayed Stochastic Logistic Growth Laws with Application in Biomedical Studies


Authors: Petras Rupsys

Abstract: The study of nonlinear stochastic delayed process is significant for understanding nature of complex system in reductionistic viewpoints. This paper investigates the stochastic linear and logistic (Verhulst, Gompertz and Richards) models, and simulates the growth process of Ehrilch ascities tumor (EAT) in a mouse. In order to explain the oscillations of EAT growth we use a system of stochastic differential equations with time delay. We derive the exact and approximate stationary densities in the case of small time delays. For the estimation of parameters we propose the L1 distance and maximum likelihood procedures. As an illustrative experience we use a real data set from repeated measurements on Ehrilch ascities tumor in a mouse. The results are implemented in the symbolic computational language MAPLE.

Keywords: Ehrilch ascities tumor, Stochastic differential equation, Density function, Fokker-Plank equation, Numerical solution.

Issue 7, Volume 5, July 2008

Title of the Paper: Phenotypic Characteristics, Antibiotic Susceptibility and Pathogenicity of Ornithobacterium Rhinotracheale


Authors: Zaini Mohd-Zain, Tan Lin Jee, Kamaruzaman Jusoff

Abstract:- Ornithobacterium rhinotracheale (ORT) has been recently recognized as one of the respiratory pathogen in poultry. This bacterium produces clinical signs in chickens which are almost similar to the infection of Avibacterium paragallinarum, thus making diagnosis difficult. A collection of 18 isolates of O. rhinotracheale obtained from diseased chickens in
Malaysia were characterized and their pathogenicity in embryonated eggs and chickens was investigated and compared to a reference strain. Antimicrobial susceptibility pattern of these isolates against seven antibiotics were determined using Kirby-Bauer diffusion test while minimal inhibition concentration (MIC) of tylosin and tilmicosin were performed using agar dilution method following the guidelines of Clinical and Laboratory Standards Institute. Biochemical and enzymatic tests results showed that the O. rhinotracheale isolates were made up of two variants that differ from the reference strain in their fermentation of arginine and glucose. Serotyping of these isolates revealed that all of the isolates were serotype A. Antimicrobial susceptibility test performed using antimicrobial disks showed that at least two of the isolates were resistant to more than three of the antibiotics tested. High (>128 μg/ml) minimal inhibition concentration (MIC) of tylosin and tilmicosin was observed in the isolates. Two representatives from these isolates were tested for their ability to cause mortality in egg embryos and their clinical manifestations in specific-pathogen-free (SPF) chickens. When compared to uninoculated embryos, these two isolates were found to cause significantly (P<0.01) higher number of embryo mortality. Infection of these isolates in SPF chickens caused growth retardation but no respiratory symptoms were observed. The results obtained in this study have provided some basic information on the properties of O. rhinotracheale that would be useful in diagnosing the disease. The understanding of its role in poultry health provides some information that could be useful in implementing preventive measures against the disease.

Key-Words: - Ornithobacterium rhinotracheale, embryo mortality, growth retardation, chickens, antibiotic resistant, Malaysia.

Title of the Paper: Decomposition of Synthetic Surface Electromyograms Using Sequential Convolution Kernel Compensation


Authors: V. Glaser, A. Holobar, D. Zazula

Abstract: - This paper reveals a sequential decomposition method based on Convolution Kernel Compensation (CKC). It operates in real time and can decompose linear mixtures of finite-length signals. Multiple-input multiple-output (MIMO) signal model is used with finite channel responses and trains of delta pulses as inputs. Our approach compensates the channel responses and reconstructs the input pulse trains in real time, when samples of the observed signals become available. Two versions of the sequential decomposition were tested: sample-by-sample and multiple sample input. The time complexity of the two approaches, is analytically evaluated and supported by the experimental measurements. Performance tests on the synthetic surface electromyograms (sEMG) provide estimations of average rate and standard deviation of the reconstructed pulse trains for single motor units (MU).

Key-Words: – Compound signal decomposition, Surface electromyogram, Real-time signal processing, Sherman-Morrison-Woodbury matrix inversion, Sequential convolution kernel compensation, antibiotic resistant, Malaysia.

Title of the Paper: Prediction of Genomic Methylation Status on CpG Islands Using DNA Sequence Features


Authors: Yoichi Yamada, Kenji Satou

Abstract: -. In mammals, cytosines of most CpG dinucleotides in their genomes except gene promoters are subject to modification by methyl group (methylation). A number of genes in a mammal are regulated developmental- specifically or tissue-specifically by the methylation. Mammalian DNA methylation contributes to regulation of gene expression, repression of parasitic sequences, inactivation of X chromosome in female, genomic imprinting, etc. Aberrant methylation results in a part of cancers and genetic diseases in human. Therefore it is required that methylation status on human genome is comprehensively revealed in each kind of cells. However, since comprehensive methylation analyses require a lot of times and large labor, methylation status on only a part of genomic regions is revealed in mammals. Because of this, machine learning using already known methylation data and prediction of methylation status on other genomic regions are important. Moreover, since sequence differences between DNA regions showing different methylation status also remain unclear, those differences should be also determined. Therefore we conducted machine learning by support vector machine using our previously reported methylation data, and predicted methylation status on DNA sequences using DNA sequence features. Furthermore we explored different sequence features among four types of methylation using random forest. Consequently high methylation prediction accuracies were observed between two different methylation status pairs. Moreover it was revealed that sequences containing CG, CT or CA were important for discrimination between them.

 Key-Words: - CpG island, DNA methylation, Human chromosome 11, Human chromosome 21, Support vector.

Title of the Paper: Characterization and Clustering of GO Terms by Feature Importance Vectors Obtained from Microarray Data


Authors: Jovan David Rebolledo-Mendez, Masanori Higashihara, Yoichi Yamada, Kenji Satou

Abstract: - In this paper it is explained a new approach for clustering Gene Ontology (GO) terms by examining microarray data related to them. By segmenting the entire ontology in a single specific level, and applying techniques as discrimination and ranking of features to those GO terms that are contained in that level, it is produced a characterization of the contained terms, as feature importance vectors related to the gene expression patterns that are included in the microarray dataset. By utilizing data mining techniques to cluster the vectors, it is concluded that this new approach may help to obtain relations that are normally hidden among GO terms, not only the ones in the same contained ontology, but also getting a trans-ontological relationship of them.

Key-Words: - Gene Ontology, Microarray data, Random forest, Feature ranking, Hierarchical clustering, Data mining, Machine learning, Ontology clustering.

Title of the Paper: Performance Evaluation of Parallel Processing Environment for Molecular Dynamics


Authors: Kenji Satou, Kenri Konno, Osamu Ohta, Kazunori Mikami, Keita Teranishi, Yoichi Yamada, Shin-Ya Ohki

Abstract: - Molecular dynamics (MD) is one of the popular applications in the research field of high performance computing. Since it requires large amount of CPU time basically proportional to the square of the number of atoms simulated, acceleration of MD is essential to simulation of large biomolecules like proteins. Therefore, parallelization of MD has been actively studied long time. However, most of the studies of parallel MD report modified or newly developed algorithms specialized to some computer architectures like vector-parallel supercomputer, and an end-user of MD software cannot implement them to popular MD software developed by other ones. In this study, we evaluated performance of four kinds of computer architectures: 1) vector-parallel supercomputer, 2) multi-processor machine with shared memory, 3) multi-processor machine with distributed memory, and 4) PC cluster. Various compiler options for parallelization and optimization were tested. Experimental results revealed that if MD software is not parallelized nor vectorized in source level, use of normal PC cluster with maximum use of optimization options in compilation is the best way.

Key-Words: - Molecular dynamics software, Computer architecture, Parallel processing, Optimization.

Issue 8, Volume 5, August 2008

Title of the Paper: Cortical Signal Recording using an Economical Microelectrode Fabricated on Printed Circuit Board


Authors: Yao-Ming Yu, Rong-Chin Lo

Abstract: - This work presents a simple, flexible and economical microwire array electrode for extracellular cortical recordings. The proposed procedure is relatively simple, even for a novice worker to implement in-house. These main steps include design and sculpturing PCB, straightening microwires, connecting PCB pattern, arraying and soldering microwires and packaging the microelectrode. A practiced researcher can assemble the microelectrode in about two hours and implant it in approximately three. The mass of this assembled microelectrode is 1.96g. The cost of the materials in the entire array is less than US$1.5, and the array is suitable for implantation in the cortex of rats for neurophysiology studies. In this study, electrochemical impedance spectroscopy is also applied to measure the impedance and the phase between the electrode and the electrolyte, and then to obtain an equivalent circuit. The improved microwire array electrode is adopted to record the extracellular cortical signal of cerebrum. The microwire array electrode can be fabricated and used for multi-site, multiple single-unit recording experiments.

Key-Words: - Microelectrode, Printed circuit board, Flexible flat cable, Extracellular, Electrochemical impedance spectroscopy

Title of the Paper: Electronic Health Records and Decision Support Local and Global Perspectives


Authors: Jose Neves, Manuel Santos, Jose Machado, Antonio Abelha, Sollari Allegro, Maria Salazar

Abstract: Safer, less expensive, and higher-quality health care can be achieved using clinical decision support (CDS), although the use of CDS often leads to disappointing results. Various problems and limitations can be pointed being the most frequently referred by the physicians the inadequate implementation of the clinical workflow. Electronic Health Records (EHR) and Patient Health Record Systems (PHRS) can play an important role in CDS mitigating those limitations and enabling the effective use of the archived information in the support of the clinical practice and generating the right knowledge to make decisions. The availability of such knowledge is crucial either, for the hospitals and for the government institutions. This brings new requirements for the EHR and PHRS conception and for the use of the information out of the boundaries of the hospitals and health centers. Interoperation and open models constitute the greater challenges that EHR enfaces in the very next future. This paper presents a survey on the design, development and implementation of PHRS in terms of organizational, regional, national and worldwide initiatives. Finally is presented the EHR implementation in the Hospital Geral de Santo Antonio, EPE, one of the major hospitals in the North Region of Portugal.

Key-Words: Electronic Health Records, Electronic Medical Records, Electronic Patient Record System, Interoperation, Terminologies

Title of the Paper: Implementation of Extracellular Neural Recording System and Study of Evoked Signal Preprocessing Method


Authors: Yao-Ming Yu, Wen-Liang Tsai, Rong-Chin Lo

Abstract: A multichannel recording system of extracellular cortex is utilized to acquire the neural signal of primary somatosensory cortex in rats. The extracellular neural recording system includes mainly the acquisition sub-system, the monitoring sub-system and the analyzing sub-system. We use the microwire array electrode to record different signal of three types; those are from on air, from S1HL without stimulation and from S1HL with stimulation by scratching the claw of the left hind leg using a brush. A signal processing system is applied to deal with the saved data. Through the method of spectral subtraction, we can reduce the influence of noise. Beside, nonlinear energy operator algorithm is employed to detect the timestamp of evoked potential by external stimuli. The signals are according to the time interval between preceding and following of timestamp to separate apart into every section. Each section can proceed to extract the features from every small segment of the signals and classify evoked potential segments that own similar features to the same group in the future. Finally, the information of the monitor system are apply to verify the accuracy of spike detection that the information comprises the action of external stimulus, the waveform of neural signal and the voice of speaker, simultaneously. Through the result of experiments, the developed recording system is suitable for intracortical signals recording; the proposed method is feasible and effective for noise reduction and spike detection of extracellular evoked potentials.

Key-Words: Microwire array electrode, Extracellular recording, Somatosensory evoked potential, Brain machine interface, Moving average, Spectral subtraction, Nonlinear energy operator

Title of the Paper: Fast Parallelized Algorithm for ECG Analysis


Authors: M. Rizzi, M. D'Aloia, B. Castagnolo

Abstract: A new approach based on the adoption of wavelet transforms is presented for the R point localization in ECG signals. The conceived real time signal processing technique, which uses a fast parallelized algorithm, has been evaluated adopting the standard MIT-BIH Arrhythmia database which includes specially selected holter recordings with anomalous but clinically important phenomena. In the procedure a soft thresholding technique is applied to dyadic scales in which the ECG signal is decomposed. Therefore, noise contribution is reduced and then signal is easily reconstructed in the time domain for further processing. Moreover, the tool analyzes the signal on different level wavelet representation at the same time showing a great parallelism degree and an enhancement in processing time. To evaluate the algorithm noise immunity, the MIT-BIH Noise Stress Test Database has been adopted containing baseline wander, muscle artifacts and electrode motion artifacts as noise sources. The obtained performance shows the method validity in terms of algorithm speed up and characteristic parameter values. In fact, sensitivity and positive predictivity values of about 99.8% are obtained with a detection error rate of about 0.4%. Moreover, the conceived procedure gives satisfactory results also for ECG signals heavily corrupted by noise.

Key-Words: ECG, QRS, wavelet transform, parallel filter bank, signal processing, parallel computing

Issue 9, Volume 5, September 2008

Title of the Paper: RF-MW Non-Thermal Effect Enhanced Beta-Galactosidase Expression through the Induction of Dnak Synthesis in E.coli BL21 DE3


Authors: Imad Aoude, Sarah Saab, Nader Aoude, Mohamed Mortada, Fatima Jebai, Mohamed Ezzeddine

Abstract: Like most of stressful environmental factors RF/MW radiation induce a higher HSP activity in absence of any heating. A low level of RF radiation exposure can also increase other enzyme activity by stimulating their expression in cells in particular the ?-galactosidase activity. The aim of our work is to study the rate of accumulation of Dnak (HSP70) and the rate of accumulation of β-galactosidase at the level of RNA messenger. We demonstrate that Dnak and the β-galactosidase synthesis changes at the level of DNAc synthesis, using RT-PCR and detection on agarose gel by UV radiation. The exposure conditions are performed with the nominal radio GSM emitter (Base Transceiver).

Key-Words: GSM radiation, E-coli, low level exposure; Dnak synthesis, β-galactosidase activity; β-galactosidase synthesis; non-thermal effect

Title of the Paper: Modular Adaptive Bionics Structure


Authors: Nicu George Bizdoaca, Dan Tarnita, Daniela Tarnita, Anca Petrisor, Elvira Bizdoaca

Abstract: Applications of biological methods and systems found in nature to the study and design of engineering systems and modern technology are defined as BIONICS. The present paper describes a bionics application of shape memory alloy in construction of orthopedic implant. The main idea of this paper is related to design modular adaptive implants for fractured bones. In order to target the efficiency of medical treatment, the implant has to protect the fractured bone, for the healing period, undertaking much as is possible from the daily usual load of the healthy bones. After a particular stage of healing period is passed, using implant modularity, the load is gradually transferred to bone, assuring in this manner a gradually recover of bone function. The adaptability of this design is related to medical possibility of the doctor to made the implant to correspond to patient specifically anatomy. Using a CT realistic numerical bone models, the mechanical simulation of different types of loading of the fractured bones treated with conventional method are presented. The results are commented and conclusions are formulated.

Key-Words: Bionics, modularity, implants, numerical simulation

Title of the Paper: Digestive Database Evidential Clustering Based on Possibility Theory


Authors: Anas Dahabiah, John Puentes, Basel Solaiman

Abstract: A new method that aims to automatically classify a set of objects in spite of the imperfection and the uncertainty of their heterogeneously-assigned data is proposed in this paper. This method is based essentially on possibility theory to estimate the similarity among the objects, and on belief theory and multidimensional scaling methods to construct the compatible evidential class partition. This method is applied to a medical database and robust results have been obtained without knowing the key attributes of the concerned pathologies and without taking into account any a priori medical knowledge.

Key-Words: Possibility Theory, Evidence Theory, Similarity, Clustering, Partition, Multi-Dimensional Scaling

Issue 10, Volume 5, October 2008

Title of the Paper: A HHT-based Time Frequency Analysis Scheme in Clinical Alcoholic EEG Signals


Authors: Chin-Feng Lin, Shan-Wen Yeh, Yu-Yi Chien, Tsung-Ii Peng, Jung-Hua Wang, Shun-Hsyung Chang

Abstract: In this paper, a Hilbert-Huang Transformation (HHT)-based time frequency scheme is applied to the analysis of clinical alcoholic and normal control FP1 electroencephalogram (EEG) signals. The differences in the responses of the EEG signals, the intrinsic mode function (IMF), instantaneous frequency (IF), marginal frequency (MF), and the Hilbert spectrum between the simulation results of the clinical EEG signals of the alcoholic and control groups are discussed. When comparing the clinical EEG signals of the alcoholic and control groups, the EEGs of the control group of picture observers did not appear to indicate significantly larger voltage. The EEG signals of the alcoholic group in the experiment suggested that when they were exposed to the stimulus, brain cells were stimulated and emitted higher voltage. From these discussion, we can recognize IMFs, IFs, Hilbert Marginal frequency, and Hilbert spectrum of EEG signals of an alcoholic and a normal observers to define an alcoholic illness.

Key-Words: Hilbert-Huang Transformation (HHT), time frequency analysis, alcoholic EEG, clinical signals, intrinsic mode function, Hilbert spectrum

Title of the Paper: New Spectral Numerical Characterization of DNA Sequences


Authors: Igor Pesek, Janez Zerovnik

Abstract: We present new numerical characterization of DNA sequences that is based on the modified graphical representation proposed by Hamori. While Hamori embeds the sequence into Euclidean space, we use analogous embedding into the strong product of graphs, K4xPn , with weighted edges. Based on this representation, a novel numerical characterization was proposed in [14] which is based on the products of ten eigenvalues from the start and the end of the descending ordered list of the eigenvalues of the L/L matrices associated with DNA. In this paper we compare two further numerical characterizations of the same type emphasizing the robustness of the approach.

Key-Words: Numerical characterization, graph representation, graph invariant, DNA sequence

Title of the Paper: An Electronic Circuit Model on Cone Cell Pathway


Authors: Hongjie Li

Abstract: In this article, an electronic circuit model on cone cell pathway is presented when a light stimulus is given to at the center of receptive field. The circuit model can simulate potential change characteristics of corresponding classes of neurons in the retina when visual information is transferred through the cone cell pathway. These characteristics include photoelectric conversion and hyperpolarization characteristics of cone cell, depolarization and hyperpolarization characteristics of bipolar cell, and action potential generation characteristics of ganglion cell. The simulation results of the circuit model qualitatively accord with potential change characteristics of the real neurons.

Key-Words: Cone cell, bipolar cell, ganglion cell, potential, circuit model, simulation waveform

Issue 11, Volume 5, November 2008

Title of the Paper: Prognostic Factors in the Evaluation of Metastatic Breast Cancer


Authors: Man Milena Adina, Cosmina Bondor, Ioana Neagoe, Monica Pop, Antigona Trofor, Dana Alexandrescu, Ruxandra Rajnoveanu, Oana Arghir

Abstract: Breast cancer continues to be a major cause of morbidity and mortality in women worldwide, one of the most frequent neoplasia in female. The evaluation of prognostic factors and the follow-up of metastases are major research areas that enable cancer patients to have maximum therapeutic benefits, increased quality of life and survival. We conducted a survey from January 2000 to December 2005 on 120 patients admitted in Cluj-Napoca Oncology Institute and “Leon Daniello” Pneumology Clinical Hospital. We introduced in the study patients diagnosed with breast carcinoma and pulmonary metastases, we analyzed risk factor and evolution of the diseases with survival function calculated since breast cancer diagnosis, and the other calculated since pulmonary metastases. Age of the patients over 60 years (p=0.01), urban areas (p=0.048), smoking (p=0.001), time between the first symptoms and the doctor’ presentation (more than 1 year) was significant statistic in both survival (p=0.005 and p=0.003). Tumor localization (p=0,95), primary tumor size (p=0,000), number of metastatic ipsilateral axillary lymph node (p=0,0212) as prognostic factor in breast cancer. Good performance status (p=0.03), the stage of the disease at presentation (p=0.004), type of metastasis, good risk class (p=0.0004), response at the treatment (only 5% had complete response) influence the survival calculated from the breast cancer diagnosis (69.15% at 1 year, 17.02% at 5 years, 4.26% at 10 years) and the survival calculated from the moment of pulmonary metastases (32.53% at 1 year, 4.82% at 5 years, 2.41% at 10 years). Since classical prognostic factors could not be predictive for all the patients in our studied group, we aimed to identify other prognostic factors . We examined the status of estrogen and progesterone receptors as unfavorable predictive factors of treatment response and found that patients with hormone receptors had a significantly higher survival than those without the receptors (p=0.0409 for estrogen and p=0.0355 for progesteron). In order to evaluate tumor aggressiveness we carried out immunohistochemical studies to detect P53 protein(p=0,012), bcl-2 gene(p=o,678) and PDGF (p=0,637) in the attempt to demonstrate that these could have been useful in assessing the future development of breast tumors The identification of prognostic factors ( with mathematics methods) is valuable due to the following three reasons: 1. Optimum treatment may be selected for each patient 2. Various therapeutic strategies could be compared among groups of patients with similar recurrence risks and treatments 3. The knowledge that allows the identification of recurrence patterns may be improved and new treatment strategies established

Key-Words: Prognostic factor, survival, metastases, breast cancer, metastases treatment, risk factors

Title of the Paper: An Effective Method for Detecting Dental Diseases by using Fast Neural Networks


Authors: Hazem M. El-Bakry, Nikos Mastorakis

Abstract: In this paper, a new fast algorithm for dental diseases detection is presented. Such algorithm relies on performing cross correlation in the frequency domain between input image and the input weights of fast neural networks (FNNs). It is proved mathematically and practically that the number of computation steps required for the presented FNNs is less than that needed by conventional neural networks (CNNs). Simulation results using MATLAB confirm the theoretical computations. One of the limitations of Direct Digital Radiography (DDR) is noise. Some recent publications have indicated that Digital Subtraction Radiography (DSR) might significantly aid in the clinical diagnosis of dental diseases, once various clinical logistic problems limiting its widespread use have been over come. Noise in digital radiography may result from sources other than variation in projection geometry during exposure. Structure noise consists of all anatomic features other than those of diagnostic interest. Limitations of plain radiographs in detecting early, small bone lesions are also due to the presence of structure noise. This research work has been under - taken in an attempt to minimize structure noise in digital dental radiography by using digital subtraction radiography. By minimizing the structure noise, the validity of the digitized image in detecting diseases is enhanced.

Key-Words: Direct digital radiography, structure noise, dental bone lesions, digital subtraction radiography, fast neural networks, cross correlation

Issue 12, Volume 5, December 2008

Title of the Paper: Multifunctional Health Information System for the Comprehensive Management of a Sleep Clinics Franchise Chain


Authors: Edgar Daniel Acosta, Francklin Rivas-Echeverria, Solange Gonzalez, Lizmar Molina, Carlos Rivas-Echeverria

Abstract: In this paper it is presented the prototype of a multifunctional Health Information System for the Comprehensive Management of a Sleep Clinics Franchise Chain. This prototype should facilitate the process by which it obtains, uses or displays a variety of basic resources to support the objectives of a Sleep Clinic, should facilitate the decision-making process, the control of the administrative and other day-to day workflow activities and the clinical management for the diagnosis and treatment of sleep disorders and related diseases. The rationale of the project is the creation of a system to ensure the availability of highly skilled and well trained staff that takes care of patients attending a specialised centre of this kind. The system has three main sub-systems, these are: a system to manage all the administrative and (or) day-to-day workflow activities aspects of the clinic. The second, is a diagnostic and treatment (decision) support system and an electronic health record, it suggests the physician a diagnostic–therapeutic plan (following standard and updated guidelines) for each patient; this rulebased subsystem has been developed following the method for building Expert Systems (ES). The third subsystem supports an educational program and training tool for the staff to ensure that they will manage appropriately all the activities of a specialized centre for diagnosing and treating sleep disorders. The paper describes the ideas supporting the design, some comments about the system architecture, the methods that we follow to build it, some conclusions, and further research.

Key-Words: Information Systems, Expert Systems, Sleep Disorders, Medical Diagnosis, Artificial Intelligence

Title of the Paper: An Exploratory Research on the NanoVectors for Drug Delivery and for Gene Therapy


Authors: Tang Shao-Pu

Abstract: The purpose of this study is to explore the application of nanotechnology to prepare optimal vectors for drug delivery systems and for gene therapy delivery. We first review various types of drug delivery systems as vectors and then to explore nanovecotrs in gene therapy. By reviewing relative literature, we found out that nano drug vectors can be administered by all possible routes of administration and will revolutionize both gene therapy and the in vivo delivery of drugs. Three relative cases, inclusive of C Montemagno's study on a biomolecular motor in Cornell University, were explored. The findings show that applying nanotechnology will provide preparing nano vectors for both drug delivery and gene therapy another promising implication.

Key-Words: Nanotechnology, Nanovectors, Biomolecular, Drug delivery, Gene therapy

Title of the Paper: Applying Boltzmann Equation to Starch Enzymatic Hydrolysis Modeling


Authors: A. Patsioura, E. Reppas, G. Maniatis, V. Gekas

Abstract: In certain enzymatic actions, such as the case of α-amylase hydrolyzing the starch, the mode of splitting the molecule is random. Various models, mostly non-deterministic, have been applied to account for this type of action, as for example the Monte-Carlo procedure. In this paper a new approach is applied based on the Boltzmann entropy equation where the multiplicity, W, has the meaning of various possible products after a given number of hydrolysis stages. Through this analysis the probability of obtaining the desirable product, which is maltose, is estimated and compared to experimental results.

Key-Words: Enzymes, enzymatic hydrolysis, starch, α-amylase, maltose, Boltzmann equation, enzymatic modeling

[Journals], [Books], [Conferences], [Research], [Contact us], [Indexing], [Reports], [E-Library], [FAQ],
[Upcoming Conferences with Expired Deadline], [History of the WSEAS Conferences]

Copyright © WSEAS