Search

Arrhythmia refers to any change from the normal sequence of electrical impulses, causing abnormal heart rhythms. With the help of well-known Beeler - Reuter mathematical model of a cardiac cell, we demonstrate that some of the clinically observed manifestations of arrhythmia property can be simulated. In our simulation study a 60×60 network of cells is considered. The cells are coupled through resistive element. These resistive elements are similar to gap junction in real cardiac tissue. An input stimulus is presented in addition to ionic current to generate action potential continuously, since ventricle cells are not oscillatory. The input stimulus is presented in a group of cells at the left most corner of the grid of cells at specific instant of time. The selection of duration and amplitude of input stimulus plays a vital role. The presentation of input stimulus makes a regular cardiac rhythm traveling from left top most corner to right bottom corner in the grid. External signals are applied in the grid of cells to disturb a regular rhythmic pattern to simulate arrhythmia condition and leads to generation of spiral waves. This situation is clinically identified as re-entrant arrhythmia. The external signals are Gaussian in nature having a frequency same as that frequency of action potential in that region. It is observed that the location of presentation of external signal leads to different kinds of abnormalities. This above study was performed using nominal initial values for all the variables. It is further observed that increase in sodium ion conductance from nominal value does not disturb the regular rhythmic pattern even with the application of external Gaussian signal. This shows an initial step in identifying the role of sodium ions in arrhythmias. Also we have studied the similar simulation study with 90×90 grids of cells. [ABSTRACT FROM AUTHOR]

Extracortical activity play important role in generation of EEG-signal. Neuronal system in the brain seems to be specially sensitive to sources belonging to the class of functions: [Acos(αt)+Bsin(αt), exp(±αt), Bessel functions]. This representation could be reflect influence of external sources, for example electromagnetic fields, on the brain. In my previous papers I demonstrated the effect of electromagnetic field on the EEG-signal using nonlinear dynamics method - Higuchi's fractal dimension. The extracortical input from inhibitory neurons destroys the oscillatory structure of signal generated by extracortical input from excitatory neurons but do not suppresses it completely. The additional component is needed. The long-distance input from excitatory neurons take this role. The most important parameter in the model is postsynaptic neurotransmitter rate constants. It shows a biphasic effect changes for inhibitory postsynaptic potentials (IPSP) in the EEG-signals during anesthesia. The similar behavior is visible for postsynaptic rate constants but in case of excitatory postsynaptic potential (EPSP) in epileptic EEG-signals. There are two opposed processes occur. The average excitatory soma potential (he) depend on total number of excitatory and inhibitory intracortical connections. The increase of maximum value of the he occurs for bigger number of excitatory connections. The shape of the curve depend on number of inhibitory connections. [ABSTRACT FROM AUTHOR]

The most important health problem affecting large groups of people is related to the malfunction of the heart, usually caused by heart attack, rhythm disturbances and pathological degenerations. One of the main goals of health study is to predict these kinds of tragic events, and to identify the patients situated in the most dangerous states, to make it possible to apply a preventing therapy. This paper presents an event recognition study performed with ECG signal analysis and 3D heart model. The signal resource was a 192-electrode measurement (BSPM) database containing various malfunction cases like WPW syndrome, atrial and ventricular fibrillation and flutter. The preliminary ECG analyzer system (PAS) is based on detailed, a priori knowledge of human anatomy and physiology, developed by an ANN, tested and validated by physicians in clinical environment. In this study the PAS was used to obtain initial information on the site of origin of cardiac activation. The ANN output provides the initial heart model parameters. Then the BSPMs were simulated by the ECG generator unit, and the objective functions that assess the similarity between the measured and simulated signals were determined. The heart model parameters are adjusted with the aid of optimization algorithms, or physicians in certain cases. The simulation procedure is performed until the objective functions satisfy the given convergence criteria. Finally the parameters are validated. During the simulation, a parameter classification algorithm was applied to distinguish normal QRS complexes from abnormal ones, in order to determine the specific differences between the normal and abnormal parameter values. For normal cases the detection ratio was practically 100%, while in pathological cases, such as ventricular fibrillation, bypass tracts, the estimation accuracy varies from 90% to 98%. At present, the performance of personal computers does not make possible the real-time determination of parameter values. The practical application is possible only in case of strongly parallel systems. [ABSTRACT FROM AUTHOR]

Most walking assist systems reported are not available for real-world environment, where frequent perturbations are resulted from slips, uneven terrain, slopes and obstacles. On the other hand, it is evident that human beings cope with those perturbations, especially when the perturbations could not be predicted or perceived in advance, with reflexes, which cause relatively fixed muscular responsive patterns to perturbations unconsciously within several 10 ms to 200 ms. Our ultimate goal is to realize artificial reflexes to real-world walking support systems for those paralyzed people. This goal needs both qualitative and quantitative understanding of human reflexive mechanism during walking. Our approach includes 1) acquiring muscle activity profiles during normal walking and slip-perturbed walking by recording and processing Electromyographic (EMG) signals of several walking-related muscles, in a human gait experiment; 2) developing a central-pattern-generator (CPG) based neuro-musculoskeletal simulation model; 3) comparing joint trajectories of simulation model with that of human suject during normal walking to verify simulation model's conformity with human walking; 4) using muscle activity profiles of reflexive responses, to construct a rapid responding pathway. The results showed that, 1) the simulation model could present conformable behavior to human normal walking; 2) in the case of occurrence of slip-perturbation, the rapid responding pathway could improve the perturbation-resistance and maintain the balance for walking. This reveals the possibility to realize the artificial reflex for the paralyzed people. [ABSTRACT FROM AUTHOR]

We aimed at evaluating the knee-joint motion quantitatively in the knee joint diseases and after total knee replacement. In the present study, we have developed an analyzing system of the knee joint motion based on the pendulum test. The pendulum test, where the leg is dropped and the knee allowed to swing passively in the manner of a pendulum, has been recognized as a reliable measure of the knee-joint motion, which is characterized by the damped oscillation waveform determined by the inertia of the leg motion and the viscoelasticity of the quadriceps femoris, as long as there is no abnormal reflection. The system consists of measurement, processor, and display systems. The measurement system, that consists of two acceleration sensors, amplifiers and A/D converter, and a computer, determines the change in angular acceleration of the sagittal knee motion during free fall of the lifted leg. The processor system computes, angular acceleration, angular velocity, and angle data, estimating viscoelastic parameters of the knee-joint motion using the Polytope method within 10 seconds. In 33 healthy subjects (age: 18-20 yo) pendulum test was performed. The estimated amplitude of the initial 3 cycles of the velocity waveform, which is especially important of evaluation of knee-joint movement, showed good agreement with those of the measured values (r=0.99, P<.001). The newly developed analyzing system for evaluation of knee-joint motion will contribute to the real-time quantitative evaluation of the diseased and replaced knee joint. [ABSTRACT FROM AUTHOR]

Both 2D and 3D mathematical models are constructed based on the co-ordinates measurement of a six time enlarged eye model. The graphical image is developed using Pro-E before exported into the COMSOL Multiphysics 3.2. The ocular surface temperature obtained for the 2D model is 33.64°C while the 3D model gives 34.48°C. The 3D model is further simulated for conditions under microwave radiation exposure (750MHz and 1.50GHz). A peak rise in temperature can be observed which agrees well with results from open literatures. These models can be improved by including more complex boundary conditions to simulate the eye to a higher degree of accuracy. The models studied here can be further applied for simulation of diseased eye by specifying proper boundary conditions with the types of diseases. Success of such simulations with appropriate neural network system will provide options for patients with third opinion regarding to the diagnosis of a particular ocular disease. [ABSTRACT FROM AUTHOR]

The potential of thermal therapy's applications improve with the development of accurate non-invasive time-spatial temperature models. These models should represent the non-linear tissue thermal behaviour and be capable of tracking temperature at both time-instant and spatial point. An in-vitro experiment was developed based on a gel phantom, heated by a therapeutic ultrasound (TUS) device emitting continuously. The heating process was monitored by an imaging ultrasound (IUS) transducer working in pulse-echo mode, placed perpendicularly to the TUS transducer. The IUS RF-lines and temperature values were collected 60 mm distant from the TUS transducer face. Three thermocouples were aligned along the IUS transducer axial direction and across the TUS transducer radial direction (1 cm spaced). Three different TUS intensities were applied. The non-invasive time-spatial evolutionary temperature models were created making use of radial basis functions neural networks (RBFNN). The neural network input information was: the propagation time-delay between RF-line echoes and the past temperature lags from three different medium locations and three different TUS intensities. A total of nine different operating situations were studied. The best RBFNN structures were automatically determined by a multiobjective genetic algorithm, due to the enormous number of possible structures. The RBFNN temperature models were evaluated with data never used in the models, neither at the training or structural selection phases. In order to precisely evaluate the model generalisation performance these data included the nine possible operating situations. The best model presents a maximum absolute error less than 0.5 degrees Celsius (gold-standard value for hyperthermia/diathermia applications). To be mentioned also that the best model presents low computational complexity enabling future real-time implementations. Concluding, a maximum absolute error below the gold-standard value pointed for hyperthermia/diathermia applications was attained. In addition, this methodology does not require a-priori determination of physical constants and mathematical simplifications required for analytical methodologies. [ABSTRACT FROM AUTHOR]

The goal of this paper is to describe a bulk-phase convection — diffusion transport of pulmonary surfactant in two-phase free surface flow. Transport in this system can be very complex because of interactions between surfactant and mechanical properties of the system (physicochemical hydrodynamics). Once adsorbed to the air — liquid interface with a surface concentration, surfactant alters an interfacial surface tension. As an interfacial stress balance, which governs the fluid mechanics, is a function of surface tension, a strong coupling exists between the surfactant transport dynamics and the fluid mechanics. Motivation for this study was the development of an understanding of surfactant transport dynamics during respiratory distress syndrome (RDS) of premature infants, where the primary pathology is due to a low bulk surfactant concentration. In this physiologically significant case, the true physicochemical dynamics cannot be adequately understood without accounting for the bulk transport processes. To model this problem, we consider the mechanics of a semi-infinite gas bubble progression in a liquid-filled rigid-walled, axisymmetric tube with radius R under steady-state conditions. The presented model extends beyond previous models of surfactant transport in the systems that may relate to airway reopening. First, the adsorption kinetics and the equation of state are described using the non-linear Langmuir adsorption model. Most previous studies used a linear relationship between the surfactant concentration and the local surface tension. Linear models are valid only for the small departures from equilibrium. [ABSTRACT FROM AUTHOR]

This paper describes the development of sensing system of human body. The main goal of our study was to expound the principle of sensing system of human body. We put forward the diagram of the model of sense mechanism. The diagram, which shows the model of human sensory system, is the basic of the modeling. We choose olfactory system, using the technology of electronic nose to measure gas. The signals can be collected by gas transducer array. We compare the method of pattern recognition of BP neural network technology and Self-organization models. The digitizing methods of sensing system model are discussed. [ABSTRACT FROM AUTHOR]

The Wolff-Parkinson-White (WPW) syndrome is characterized by an accessory pathway (by-pass tract) between the atria and ventricles, that conducts parallel with the atrioventricular (AV) node - His bundle, but faster. Usually the WPW analysis is focused to develop and validate an accessory pathway (AcP) localization method. In this paper we present a sensibility analysis of Arruda's stepwise method, and a decomposition algorithm to improve the performance of AcP localization. Our main purpose is to detect more accurately the location of the ventricular insertion, because that can enlighten the necessary RF catheter ablation of cardiac tissue (shorter intervention due to correct localization of AcP), which is highly effective in the invasive treatment of WPW syndrome. We developed a modified Arruda localization method, which was tested and evaluated through our measurements. Although it has been statistically concluded, that the performance of the Arruda algorithm is about 90%, our study revealed that some modifications in this localization method could be beneficial. The Arruda method was tested on a total of 79 patients, and 91.1% correct localization performance was reached. With modifications in the left ventricle region, this performance reaches 94.9%. After a deeper analysis of each decision point of Arruda localization method, we considered that the lead aVF is not as relevant as other used leads (I, II, III, V1). Despite lower decision performance of aVF sign tests in the right and septal region, they cannot be wisely replaced within the scope of the 12 lead ECG. The modified algorithm significantly improves the localization performance in the left ventricle. Finally we can conclude the followings: (1) Arruda's leads used for the detection of septal and right regions seem to give optimal solution in the scope of 12-lead ECG; (2) Significant improvements are achieved in the left ventricle; (3) A more accurate analysis requires further studies and a significantly larger database. A high localization performance of non-invasive methods is relevant because it leads to easier invasive interventions, and also reduces the discomfort caused to the patient. [ABSTRACT FROM AUTHOR]

Capnography, the monitoring of exhaled CO2, has been clinically utilized as a noninvasive measure of alveolar ventilation. The shape of the capnogram is significantly altered in patients with lung disease or hemodynamic instability. Shape indices obtained from the capnogram provide an indication of dead space ventilation, ventilation/perfusion status, and the extent of rebreathing. In this study, the quantitative relationship between physical respiratory parameters and capnographic shape indices was determined using a mathematical model of CO2 exchange in a tidally ventilated lung. This relationship may provide clinicians with guidance for physiological interpretation of capnograms. [ABSTRACT FROM AUTHOR]

When a thenar muscle is performing a maximum isometric contraction and supramaximal stimulus is applied to median nerve, there is a silent period (pause in electrical activity) in the electromyogram(EMG). In this paper, a new model of EMG-signal generation including silent period in thenar muscle is proposed. This work was based on anatomical structure of spinal nerve system and characteristics of neuro-physiological data that are related on carpal tunnel syndrome. Also in this paper, to obtain real EMG-signal including silent period from normal subjects without neurological alterations and carpal tunnel syndrome patients. As a result, if there is the symptom of carpal tunnel syndrome, the EMG-signal, the summation of silent period is in normal silent period. It is possible to see that the summation of silent period is long as the symptom of carpal tunnel syndrome is severe and that there is correlation between carpal tunnel syndrome and silent period. [ABSTRACT FROM AUTHOR]

We construct a pattern recognition system by modeling the structure of the visual cortex. The complexities of the visual cortex can be simplified by understanding that the neurons of this region are distinguished by the features of input image that each neuron detects. We propose a neural network(NN) model of the simple structure based on the function and structure of the visual cortex. Moreover, a lot of ideas of manufactured products with NN were proposed. One of issues for productization is uncertainty of the behavior of nonlinearity of NN. Accordingly, it is important to analyze the internal representation of NN. In this paper, we discuss the recognition and training mechanism of a NN model by use of Alopex algorithm. Alopex algorithm, which is an iterative and stochastic processing to minimize or maximize a cost function. processing to minimize or maximize a cost function. By this method, the receptive fields of the units in the output layer are obtained. We have proposed a four-layered feed-forward NN model for pattern recognition and analyzed the recognition mechanism as well as the performance of the model. We proposed a modified Alopex algorithm and calculated the receptive fields of the output unit. In the case of simple training character set, the receptive field changes according to the values of initial weight vectors. If the initial values are large, NN uses small amounts of input values for the classification. In contrast, if the initial values are small, NN uses whole input image. Moreover, it was seen that as the complexity of the set of training patterns increased the receptive field of the output unit changed. Smaller initial values of weight vector have advantage to get the more features. Alopex algorithm is an effective method to find the characteristics of images. [ABSTRACT FROM AUTHOR]

In order to improve new materials as middle ear prostheses, a method for evaluation of transfer function of these materials had to be developed. The measurements were performed in three stages. First, a mechanical middle ear model was designed which should simulate the mechanical and acoustical characteristics of intact middle ear. In this model different commercial prostheses and newly developed implants were measured by means of Laser Doppler Velocimetry (LDV). To control the stiffness of the system, we used Tympanometry as well as Multi-Frequency Tympanometry (MFT). In the second and third stages the same evaluations were followed in fresh human temporal bones as well as in animal experiments. The measurements in the mechanical middle ear model indicated a good comparability with the transfer function of the intact middle ear, particularly up to resonance frequency of the middle ear, which was about 1200-1500 Hz. The influences of mass and stiffness could be determined appropriately using the middle ear model. The measurements with different prostheses resulted in no significant variations in the transfer functions of commercial and new implants. The results of experiments on fresh temporal bones again showed no significant variation in the transfer functions of different prostheses. A median damping of about 15 to 20 dB particularly beyond the resonance frequency was measured using implanted prostheses relative to the transfer function of the intact ossicular chain. Also the results of MFT measurements in animals on the implanted and non-implanted side (300 days postoperative) will be presented. [ABSTRACT FROM AUTHOR]

Aim of this study is intended to develop a noninvasive methodology of assignment of arterial parameters of man. In a paper there are presented the method and preliminary results of arterial parameters. The parameters were assessed using a non-linear model based on electric analogy between a transmission line and arterial tree. Parameters of the model and also of the arterial tree were identified from signals measured non-invasively on a human body — phonocardiographic signals. [ABSTRACT FROM AUTHOR]

A bond graph model for simulating cardiovascular haemodynamics is proposed. The model is given by an elastance variable description of heart, head and neck circulation, pulmonary circulation, coronary circulation, abdomen circulation and extremity circulation. Also, the carotid baroreflex control mechanism for circulation is embeded. The model responds to sympathetic and vagal activity by modifying systemic peripheral resistance, heart rate and ventricular end-systolic elastance. It is able to simulate the blood pressure and blood flow wave on arbitrary segment of circulation system, subsequently, the cardiovascular parameters such as stroke volume, cardiac output and eject fraction of heart can be computed. The simulation results under physiological condition are in agreement with human physiological experimental data. By modifying the arterial compliance and balance point of barorecpter, the hypertension is simulated and the results are consistent with the pathological features. In conclusion, the model could simulate the performance the cardiovascular system validly. [ABSTRACT FROM AUTHOR]

This paper uses a coronary arterial tree model generated by the optimization algorithm for blood volume in a two-dimensional circular region. Using the geometric data from the computed arterial tree, we analyzed the flow and pressure at each segment. The node equation algorithm to determine the flow and pressure was developed to analyze the hemodynamics in a vascular network. This simplified method was applied to a complicated vascular network. Then, we simulated what would happen to the flow and pressure in the surrounding segments if a specific segment was blocked. Computational results showed that the blood in the vessels after the blocked artery was stagnated and low pressure region was formed, inducing ischemic tissues. [ABSTRACT FROM AUTHOR]

Gene expressions are different depending on tissue types and developmental stages. It is important to analyze how each gene is expressed. One way of analyzing the gene expression pattern is to find the tissue-specific functions. It is useful to understand how vital activities go on. Nowadays, DNA microarray has been widely used to observe gene expressions exhaustively. However, it is impossible to compare the expression value of a gene to that of the other genes because the gene expression value of a condition is measured as a proportion of that of the same gene at a control condition. Therefore, we cannot determine whether one gene is more expressed than the other genes or not and what is the tissue-specific function. Cap Analysis Gene Expression (CAGE) allows high throughput analysis of gene expressions by counting the number of cDNAs of expressed genes. CAGE enables us to compare the expression value of the gene to that of the other genes in the same tissue. In this research, we propose a method for exploring tissue-specific functions by using the data measured by CAGE. To find out tissue-specificity, one of the simplest ways is to assume that the function of the most expressed gene is regarded as the most tissue-specific. However, the most expressed gene in a tissue might highly express in all tissues such as house keeping genes. Function of such genes cannot be tissue-specific. In order to remove them, we propose a measurement of tissue specificity of the functions that is based on information contents of Gene Ontology terms. We apply our method to the data of 14 tissues of human and 22 tissues of mouse. We picked up the results of mouse and human livers and that well-known functions of liver such as immune function became high rank. [ABSTRACT FROM AUTHOR]

Pair wise sequence alignment scheme has been emerged as an efficient computational tool to find region of similarity among sequences of proteins and nucleic acids. As new disease causing viruses are emerging rapidly, new alignment schemes with the advent of fast computers have gained its importance recently. In this paper, we have proposed a block based semi-global alignment scheme to evaluate the optimal alignment between any given two DNA sequences. DNA sequences are divided into blocks of equal length and alignment between the block is determined using dynamic programming. The performances are evaluated in terms of overall matrix score and percentage of similarity. It is inferred from the results, that higher the percentage of similarity between any two blocks, it may code for the same protein/amino acids. The computational complexity of the proposed algorithm is much less compared to that of the general global alignment scheme with O (M, N). [ABSTRACT FROM AUTHOR]

Homolog search is the central approach to find out the characteristics of given sequence since homologs share the similar biological role. However it is not easy to detect remote homolog because they do not show distinct sequence identity. We constructed the protein similarity network weighted by sequence and structural similarity, and utilized it to identify homologs. When comparing the ROC50 curve, our method detected twice more homologs at the SCOP superfamily level than PSI-BLAST. Our study demonstrates that exploiting protein structure similarity network improves remote homolog search by reflecting global information in protein space which cannot be detected by conventional localized search methods. [ABSTRACT FROM AUTHOR]

Protein comparison is one of the kernels on the field of bioinformatics. Although many structure alignment techniques have been developed, most of them require the implicitly incorporating sequence order constraint, which not only sacrifices the accuracy of the result but also increases the difficulty or makes the computation expensive. In this paper, we propose a new method, to improve the accuracy for protein comparison. The basic idea is to combine sequence and structure information together in the protein comparison. There are two novel aspects in this paper. One is that amino acid information is used as sequence information instead of using sequence order, which makes the computation efficient. The other is that high quality comparison between a pair of proteins can be obtained by validating sequence similarity and structure similarity mutually. The experiments are conducted on structure alignment benchmark dataset, comparison of circularly permuted proteins, comparison of protein surface patches and pockets, which demonstrate efficiency and effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Identifying interacting proteins is essential for understanding protein functions and biological signal transduction pathways. Domains as basic components of a protein are believed to be responsible for the physical interaction of a pair of proteins. Most of existing methods based on domain information are probabilistic and assume that domain interactions are independent. In this paper, we propose a new framework based on a deterministic model to infer protein interactions. The model employs a parsimony principle, i.e., the observed protein interactions are contributed by as few as possible different interacting domain pairs. It can be formulated as an integer linear programming which is in turn solved by its linear programming relaxation. We use real protein interaction data to verify our model and algorithm. Experiment results show the effectiveness of the proposed model and algorithm and demonstrate that such a parsimony principle can achieve the prediction accuracy comparable to that of maximum likelihood method. [ABSTRACT FROM AUTHOR]

We propose a computational inference of transcriptional regulatory networks from transcription start sites identified by Cap Analysis of Gene Expression (CAGE). Inference of the regulatory networks is a challenging task, and is performed by analyzing observed dependencies of transcription levels. Binding of transcription factors to an upstream sequence of a gene enables transcription initiation from a specific genomic position. The position is called Transcription Start Site (TSS). Eukaryotes have multiple TSSs for a single gene, which reflect diversity in combinatorial regulation by transcription factors. By the CAGE high-throughput profiling genome-wide identification of activated TSSs under various experimental conditions yields CAGE transcriptome datasets. To distinguish transcription responses caused by the diversity in combinatorial regulations, inference that takes multiple TSSs into account will be more effective than the conventional ones using only transcription levels of microarray dataset. In this paper we report a feasibility study of inference of transcriptional regulatory network by using CAGE dataset. This is a preliminary study for inference that takes multiple TSSs into account. To perform inference of the regulatory networks, we used Bayesian network model which is appropriate to represent distribution of TSSs observed in CAGE dataset. Using the CAGE dataset published from the FANTOM3 project in RIKEN, we applied the model to inference of the regulatory networks of Mus musculus. For the purpose of the feasibility study, we compared inferred networks from the CAGE dataset with those from microarray dataset. Based on the comparative analysis, we confirmed that network inference by using the CAGE dataset is feasible like the case of conventional inferences by using microarray dataset. Based on the confirmation we discussed what we can reveal through the inference that takes into account multiple TSSs identified by a CAGE dataset. [ABSTRACT FROM AUTHOR]

In this paper we propose a novel biological reasoning technique to find genetic palindrome using the resolution- based ATP (automated theorem proving) computing strategy. To retrieve the palindromic sequence, we apply automated deduction software with some resolution strategies to increase program performance. While the conventional reasoning or logic programming oriented method is basically top-down process, our method is bottom-up, resolution-based and also enhanced by direction and restriction reasoning strategies. Proposal method is divided into two steps. First, each element of sequence is represented as one state clause. Second, biological reasoning program resolve these states to retrieve palindrome motif from genetic sequence. Besides, to make this resolution process faster, we apply a reasoning strategy called resonance restriction. This resolution strategy blocks the biological reasoning by avoiding expression that do not mach the patterns set by researchers. This pattern is called "resonator" which is expressed by symbol patterns in automated reasoning. In our model, researcher assigns resonators to the gap between repeated regions which prevent his program from redundant search related non-symmetric parts of genetic sequence. Resonators restrict discovery process by discarding clauses generated around the gap between palindromic motifs, which enhance sharply the performance of reasoning program. In experiment, we translate whole genome sequence of Escherichia coli into clausal representation. Numerical results are presented about the retrieval of palindrome in Escherichia coli to valid the effectiveness of proposal technique. We validate that resonance restriction makes reasoning process faster with experimental output of generated clauses, CPU time. [ABSTRACT FROM AUTHOR]

The paper relates to a project on the development of advanced clinical information systems (CIS). These are capable of storing, displaying and manipulating multiple data types across the Biological Continuum (BC) — the continuum which comprises systems, viscera, tissue, cells, proteins and genes. In this context, we address the issue of multi-layer visualization of cartilage wear at the visceral, tissue and cellular levels. In many areas of application there may be a wide range of image data (both 2-D and 3-D) across the BC. In the treatment of cartilage defects, in addition to the use of minimal access surgical techniques, there have been rapid developments in tissue engineering and cell-based therapy. Imaging at all levels of the BC is important in this context in order to undertake effective diagnosis and to monitor the success of treatment. This is generally achieved using different imaging modalities. There is therefore a need to readily access and view the full range of data. This has required the development of visualization and navigation techniques across the levels. As a result, we have developed a web-based interface which allows the viewing of 2-D and 3-D image data from different levels of the BC seamlessly, despite the fact that the data may well be from different modalities. We will present a case study using porcine cadaver knee specimens which have been used to investigate cartilage wear. A number of objectives have been achieved in the study. (i) Geometrically matched sets of images have been obtained from the visceral, tissue and cellular levels of the BC using different imaging modalities (i.e. MRI, light and electron microscopy); (ii) Cartilage wear has been visualized in a manner that will aid diagnosis; (iii) The geometric framework concept has been demonstrated by visualizing the matched sets of data using our interface. [ABSTRACT FROM AUTHOR]

Echinococcus granulosus is one of the most important and widespread of the helminthes zoonoses. We collected the feces of 514 dogs, which is living 6 districts of Ulaanbaatar and sorted from feces the proglottids of E.granulosus and other taenidae parasites. Two immunodiagnostic tests (ELISA) based on genus specific coproantigen detection or serum antibody (IgG) detection were compared against immunoflourescence for the detection of E.granulosus in naturally infected dogs in Mongolia. The sensitivity of immunofluorescsence analysis was 85.7%, sensitivity was 91.6%, reality was 10.3, negativity and positivity were 90.3%. The ELISA and proglottid revealing analysis was real, sensitivity of immunofluorescsence analysis was 100%, sensitivity was 78.5%, reality was 4.7, negativity and positivity were 83.3%. We compared the above results and consider, that to diagnese of E.granulosus is useful combined with several methods especially ELISA. [ABSTRACT FROM AUTHOR]

This paper introduced the application of hot-embossing technology (HET), a particular kind of thermoplastic replication process, to the development and fabrication of piezoelectric micro-pumps with non-moving valves. Typical development adopted in fabricating micro-pump was silicon-based MEMS (micro-electronic-mechanical system) process, e.g. DRIE (deep reacting ion etching) or ASE (advanced silicon etching), to obtain a fluidic channel with vertical wall inside the silicon wafer. The piezo-disc actuator was manually mounted onto the glass membrane. A cost-effective approach for the fabrication of micropump was conducted in this study and presented. A nonmoving- part (NMP) valve micro-pump using plastic wafer was designed, and the critical wafer with micro-fluidic channels was fabricated by HET process. Critical dimensions were inspected, and optimization of the HET process was done to minimize the dimensional deviation from the design. The embossed plastic wafer and a piezoelectric actuator were then mounted and sealed on a glass membrane. Testing of the assembled micro-pump was conducted and performance, in terms of flow rate and maximum pressure head versus frequency applied to the piezoelectric disc, was evaluated. [ABSTRACT FROM AUTHOR]

We present a simple receding meniscus induced method to capture non-adherent yeast cells onto microwells inside microfluidic channels. Microwells were fabricated by capillary molding onto glass substrate using a UV curable polyurethane acrylate (PUA) solution, leading to well-defined, robust microstructures. A cell suspension of the budding yeast, Saccharomyces cerevisiae, was introduced into microfluidic channels by capillary filling and a receding meniscus was subsequently generated by evaporation. As the meniscus receded, one to five yeast cells were spontaneously captured onto microwells by lateral capillary force created at the thin region of the meniscus. Using this cell-based platform, we observed the response of yeast cells upon stimulation by a mating pheromone (α-factor) by monitoring the expression of green fluorescent protein (GFP) with time. It was observed that α- factor triggered the expression of GFP at 60 min after stimulation and the fluorescence intensity was sustained for additional 60 min without changes. [ABSTRACT FROM AUTHOR]

ZnS/CdSe/ZnS quantum dots quantum well (QDQW) were synthesized using a microfluidic reactor. The shell structure was controlled homogeneously and accurately by this system. The synthesized QDQW emitted blue fluorescence. Furthermore, we were able to tune the fluorescence wavelength by controlling the flow rate in CdSe layer deposition process. Our results demonstrate that CdSe was embedded uniformly in the ZnS core and shell by using the microreactor system. [ABSTRACT FROM AUTHOR]

Airway closure and reopening are characteristic of a variety of pulmonary diseases. Unique microscale air-liquid two-phase fluid motions during airway reopening generate large mechanical stresses, which may be deleterious to airway epithelial cells in the small airway system. Here we describe micro-engineered biomimetic in vitro airway systems and injury of pulmonary epithelial cells due to fluid mechanical stresses imposed by airway reopening. Using compartmentalized microchannel networks fabricated by soft lithography, we demonstrated long-term microfluidic culture of pulmonary epithelial cells. Airway reopening was reproduced in the microchannels by using air-liquid two-phase microfluidic systems that use air bubbles to form liquid plugs. We found that plug propagation and rupture during airway reopening cause cellular injury by exerting high levels of fluid mechanical stresses on pulmonary epithelial cells. [ABSTRACT FROM AUTHOR]

This paper reports design, fabrication and measurement results of a flexible microelectrode array for monitoring compound nerve action potential (CNAP) of a peripheral nerve. For building electrical nerve-signal-database up, the flexible microelectrode array was fabricated through a ‘polymer/metal multilayer processing technique' on a silicon wafer, and it was released by chemical ‘etch-release' scheme which results in no mechanical stress on the device. In vitro test had been conducted to examine interfacial impedance and signal transfer characteristics. The interfacial impedance was 420Ω/µm2 at 1 kHz. In vivo test had been carried out by implanting an assembly (composed of microelectrode array and a polygloycolic acid conduit) into a sciatic nerve of 10 male rats where nerve defect was 6 mm. after 3 month-implantation periods, sciatic nerve function was tested with gait analysis, and CNAP by using a bio-amplifier which was developed soley for this application. From the gait analysis, it was ascertained that nearly half of the original functions was restored, which is backed up by sciatic nerve function index (SNFI), −48.5±15.0. CNAP of the regenerated nerve through the proposed microelectrodes was examined through transmission electron microscope (TEM) images. From the TEM images, it was confirmed that proximal and distal nerve showed nearly same morphology and axon number. [ABSTRACT FROM AUTHOR]

In the present paper, we discuss the suitability of various magnetic nanoparticles for different biomedical heating applications. Several magnetic iron oxide particles in the particle size ranging from 10 nm to 100 nm were prepared by chemical precipitation and magnetically characterized with respect to their specific heating power in alternating magnetic fields. The biomedical applications of the investigated particles are focused on magnetic hyperthermia, thermoablation, and magnetically induced remote controlled drug delivery in the gastrointestinal tract. [ABSTRACT FROM AUTHOR]

In this study, a novel artificial renal replacement system is presented using a biocompatible polymeric nanofibers and MEMS technology. Usually, a classical artificial renal replacement system employs a semi-permeable membrane based hemodialyzer that replaces an ability of the kidney by removing metabolic toxins through diffusion and hydraulic pressure gradients. But, it has some limits in efficient filtration of metabolic byproducts (e.g.: urea, creatinine, and so on). We have developed PDMS based artificial renal microchips integrating biocompatible polymeric nanofibers which are utilized for the filtration of blood. Here, we demonstrate a new artificial renal chip by integrating a high efficient biocompatible polymeric nanofibers membrane with the PDMS based micro - fluidic platform. Via the optimization of PDMS micro fluidic channel network and the multiple packaging of nanofibers membrane, we will realize the portable and wearable artificial kidney system [ABSTRACT FROM AUTHOR]

This paper examines the ability to measure the velocity of both physiological saline (PS) and in vitro blood in a rectangular polydimethysiloxane (PDMS) microchannel by means of the confocal micro-PIV system. The PDMS microchannel, was fabricated by conventional soft lithography, had a microchannel near to a perfect rectangular shape (300µm wide, 45µm deep) and was optically transparent, which is suitable to measure both PS and in vitro blood using the confocal system. By using this latter combination, the measurements of trace particles seeded in the flow were performed for both fluids at a constant flow rate (Re=0.021). Generally, all the velocity profiles were found to be markedly blunt in the central region mainly due to the low aspect ratio (h/w=0.15) of the rectangular microchannel. Predictions by a theoretical model for the rectangular microchannel have showed fairly good correspondence with the experimental micro-PIV results for the PS fluid. Conversely, for the in vitro blood with 20% haematocrit, small fluctuations were found on velocity profiles. [ABSTRACT FROM AUTHOR]

Integrative micro-valve array is one of useful tools for the drug discovery, high-throughput screening. In this paper, we have developed a low-cost and easily manipulative pH-responsive micro-valve array. To prove the feasibility, we designed and fabricated the double micro-valves array, the tetrad micro-valves array and the octad micro-valves array. The platform of arrayed valve was fabricated by using polydimethylsiloxane (PDMS) and the microsphere utilized as an actuating element was produced via "on the fly" photopolymerization method. The microspheres were manually incorporated into the arrayed PDMS platform. To construct the platform of valve arrays, we stacked 3 thin (thickness: around 140µm), patterned PDMS layers (hole-layer, membrane-layer, and upper-layer) and one PDMS bas-relief plate (thickness: around 8 mm), and the top was covered with the cover slip. The actuating pH-responsive microspheres (diameter: around 140µm) were incorporated into the microvalve units and they are located in the 700µm interval. Each valve unit was controlled to be opened and be closed by changing pH solutions passing through it. The operation and the function of the fabricated micro-valve arrays were evaluated through the diverse experiments. The integrated system was operated expediently and functioned well. The closing and opening times were around 50s and 60s, respectively. Sample solution-flow rate is 0.03 ml/min when the pressure is 50kPa operated by varying the height of water column. Linear flow control was achieved over a wide range of operating flow rates. Furthermore the fabrication process of pH-responsive-actuated micro-valve arrays using PDMS is simple and its performance is suitable for a disposable lab-on-a-chip. These stimuli-responsive micro-valves do not use any electrical or mechanical components, and have many potential applications. [ABSTRACT FROM AUTHOR]

Due to the progress of Human Genome Project, microfluidic microarray has become an effective tool for genomic analysis applications such as gene expression profiling in recent years. In this setting, each single strand oligonucleotide (oDNA) that serves as a probe attached on the microarray surface can bind with its genomic counterpart with specific designed sequences in solution phase. The binding mechanism between single strand DNA probe and its target known as DNA hybridization reaction usually takes from 6 to 24 hours depending upon the testing biological samples of interest as well as the experimental conditions. In addition, hybridization efficiency is linked to binding energy barrier that is hindered by the sequence affinity. Hence, overcoming the duration and efficiency issues of DNA hybridization presents a great challenge to microarray experiments. In this study, a computational model which consists of an inlet channel, outlet channel and single reaction cell is constructed to characterize the effects of vital experimental parameters such as infusion sample flow rate, sample size and reaction kinetic constants on the efficiency and duration of oDNA hybridization. Simulation results reveal that higher infusion flow rate as well as smaller sample fragment can accelerate the hybridization process. And the reaction kinetic constants determine the binding affinity under the equilibrium condition. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new fabrication method of pH-responsive microfluidic valves and suggest the feasibility as a microminiature systems without peripheral devices. Conventionally, in-situ photopolymerization method has been employed to build the micro functional structure inside microfluidic channel. Here, we suggest a new method allowing the mass production of stimuli-responsive microsystem through the use of pre-made microstructure as actuating element like assembly of commercial products in the factory. We have massively fabricated pH-responsive microspheres that act as actuating component through the use of PDMS-based microfluidic apparatus and ‘on the fly' photopolymerization method. By the incorporation of this microsphere into the microvalve during the fabrication process, we have produced the pH-responsive microfluidic valve in a simple way. The operation and the function of the fabricated microvalve were evaluated through the diverse experiments. The microvalve was successfully fabricated, and functioned well according to the pH change. [ABSTRACT FROM AUTHOR]

In plant cell culture, the delivery of nutrition and gas (mainly oxygen) to the cells is the most important factor for viability. In this paper, we propose a poly(dimethylsiloxane) (PDMS)-based micro culture system that is designed to have good aeration. PDMS is known to have excellent air permeability, and through the experimental method, we investigated the relation between the degree of air delivery and the thickness of the PDMS sheet covering the culture chamber. We determined the proper thickness of the cover sheet, and cultured protoplasts of Nicotiana tabacum in a culture chamber covered with a PDMS sheet whose thickness 400 µm. The cells were successfully divided, and lived well inside the culture chamber for 10 days. In addition, protoplasts were cultured inside the culture chambers covered with the coverglass and the PDMS sheet respectively, and the microcolonies were formed well inside the PDMS covered chamber after 10 days. [ABSTRACT FROM AUTHOR]

In this paper, we have electrofused two cells which are P. japonicum and G. littoralis at the ‘Lab on a Chip' level. The microchannel platform was fabricated using poly(dimethylsiloxane)(PDMS) via the conventional softlithographic procedure, and the microelectrode patterns (we e-beam evaporated the titanium (as seed layer) and the gold with the thickness of 200 Å and 3000 Å and patterned by the chemical etching) were created on the surface of glass. Both the PDMS platform and electrode glass were aligned and combined via the oxygen plasma-treatment. The channel has two inlets and two types of cells were slowly introduced by using the syringe pumps and we stopped when the cells were positioned around the electrodes. We have applied 1 - 2 MHz AC field (Amplitude: 8 - 10 p-p) with rectangular wave shape to the microelectrodes to form the pearl-chain between the electrodes. Then, the cell-membranes contact closely each other. For the cell fusion, we again applied short DC pulse (amplitude: 250V/mm, duration: 10 - 100 ms) to the microelectrodes. A little pore was generated and finally two cells were fused to single cell. The fused cells were cultured in Nitsch medium containing growth regulators and some cells were cultured. We will investigate their viability with FDA (fluorescein diacetate). This results may encourage the maximum yield of 1: 1 heterologous fusion under the micro environment. [ABSTRACT FROM AUTHOR]

Recently, chip based fabrication of curved microstructures, such as microsphere, microfiber and microtube, has attracted much attention owing to their many advantages. In this paper, we have fabricated pH-responsive flexible microfiber using the microfluidic chip and ‘on the fly' photopolymerization method, and we characterized their mechanical and swelling properties. First, we have measured the swelling properties according to the pH variation. The PDMS based test apparatus was prepared, and we inserted the microfiber and measured the volume transitions. The shrinking and the swelling motions were measured according to the different sized (50, 80, 100µm) fibers to investigate the size effect. The effects of acrylic acid (AA, pH sensitive monomer) concentration were examined also. As the fibers' diameter increases, the response of volume transition was slow, and higher AA showed larger volume expansion to the application of basic solution. Second, we have measured the elasticity of microfiber according to AA concentration (weight %: 6, 11, and 22). The elasticity at the fiber having less AA concentration was larger, and this indicates that the fiber having lower AA concentration is softer. The advantages of our fabrication method are as follows; 1) the process is simple and cost effective, 2) we can functionalize the fiber and this can be applied to diverse microdevices such as sensors or actuators, 3) the size can be easily altered via the regulation of flow rate. Here, we showed the fibers' mechanical properties, and we expect that the microfiber can be applied to the fabrication of artificial muscle. [ABSTRACT FROM AUTHOR]

Recently, various micro injection pumps with different driving forces have been reported. However, attributed to the poor performance and reliability of valves in the micro scale, no micro suction pump has found a successful application thus far. In this paper, a valveless micro suction pump, using a solid chemical propellant, azobisisobutyronitrile (AIBN), is developed for the first time. This novel pump is designed based on the Bernoulli Principle applied to a Venturi tube. That is, for an incompressible fluid, a negative pressure is generated as the fluid is accelerated through a vena contracta section. In the designed pump, the width of the vena contracta section is 350 µm, and the width ratio of the input fluid inlet and the vena contracta section is approximately 8.5:1. The core of this pump is a propellant chamber with an AIBN matrix, which generates biologically inert N2 gas as it is heated by an underlying micro heater. The generated gas passes through the Venturi tube producing a negative pressure at the front section of the vena contracta in the Venturi tube. The pump and channels are fabricated by curing polydimethylsiloxane (PDMS) on a silicon mold which was patterned using the deep RIE process. The micro pump is tested for sampling porcine gastric juice. Heating the AIBN core for 3 seconds successfully pumped approximately 20 µℓ of gastric juice, showing the pump's potential applicability to various lab-on-a-chip devices and systems. [ABSTRACT FROM AUTHOR]

Electrical impedance measurement methods have been proposed to study a large number of physiological events, especially due to the simplicity, low-cost and noninvasiveness of the technique. Acupuncture (Biological active points: BAPs) research has since become a very broad active area both in Asia and the West. These points are not uniformly distributed across all parts of the human skin and investigated in various ways for the purpose of scientifically establishing their existence. This paper describes a system to measure the characteristic frequency and reactance of BAPs and surrounding skin. The method uses the three-electrode technique with a constant sinusoidal current. The measurements were taken at 50 different frequencies between 1 Hz to 1 kHz. The input peak current value was set to below 5 µA maximum in order to reduce the electrical stimulus as much as possible. We show the dependence of the reactance on frequency, measured at PC-3, PC-4, PC-7 and the surroundings skin. The BAPs measuring method is well illustrated by a simple model of an equivalent electrical circuit that correlates well with experimental results. The values of the chosen components were determined to fit the equivalent circuit using the simulation. A new BAPs measurement system has the superior characteristics of noninvasiveness measurement and easy operation. The characteristic frequencies of BAPs are 20-30 Hz higher than that of the surrounding skin, and the reactances are about 45-50 KΩ smaller than that of the surrounding skin. The reactance and characteristic frequency of BAPs and surrounding skins can be observed simultaneously, which enables objective analysis. This system has the advantage of being able to instantaneously observe the characteristic frequency and reactance of BAPs. [ABSTRACT FROM AUTHOR]

In this study, we compared the observation experiment of a liquid-liquid interface with a simulation result about the three-phase micro channel used for an extraction reaction. As a result, each flow rate ratio greatly influences the formation of the three-phase flow. And the result of computing this multiphase flow model is corresponding to the experiment well, so the development of the unit chemistry operation model will become possible with the simulation in the future. [ABSTRACT FROM AUTHOR]

We present a document imaging system which scans various types of ECG sheets and stores the scanned sheets as JPEG image files to be retrieved by cardiologists. In our implementation, we use two simple machine learning techniques: one for classifying the ECG form and the other for recognizing a required set of attribute values depending on the scanned form. In order to classify an ECG form, as a training step, we built an average histogram for each ECG form using a pre-classified set of training data. A newly scanned image is assigned to the form that is in nearest distance on its histogram. To recognize a set of important attribute values, we used a multi-layered neural network and back propagation algorithm normally used in OCR. ECG sheets differ in layout and thus attributes. We analyzed each form of ECG sheets and constructed an XML file representing a set of attributes whose values are to be recognized later on. We have tested our system with a number of sheets printed from six different ECG devices including 12-lead ECG and Treadmill. When a 12-lead ECG sheet is scanned by a high-speed scanner, for instance, its image is classified and saved into the corresponding class, and a major set of attribute values is recognized and saved in the system's database; in our case, we use the attributes such as the patient's number, test date and time, Rate, PR, QRSD, QT, QTc, Axis (P, QRS, T). [ABSTRACT FROM AUTHOR]

The use of telemedicine in speech and language pathology provides patients in rural and remote areas with access to quality rehabilitation services that are sufficient, accessible, and user-friendly leading to new possibilities in comprehensive and long-term, cost-effective diagnosis and therapy. Online collaboration environments which are used for online collaboration, communication and learning can be used for "telespeech therapy" delivering quality results while significantly reducing travel expenses and telecommunications costs. [ABSTRACT FROM AUTHOR]

In order to take all the advantage of Home Telehealth applications, it is necessary to classify the traffic of the different services and to guarantee each of them the appropriate performance parameters for multiple scenarios. In this paper we propose to use the Differentiated Services (Diff-Serv) architecture proposed by the IETF to formalize four service categories capable of supporting patient-to-doctor or patient-to-health centre secure data communication. With DiffServ, IP packets are marked in concordance with a previously agreed service classification, and nodes are configured to apply different PHBs to differently marked traffic flows. Our proposed architecture aims to guarantee network performance according to applications needs at patients' home premises and health care centers. [ABSTRACT FROM AUTHOR]

Bluetooth is a short-range radio link conceived of replacing cable connections among portable and/or fixed electronic devices. As its robustness, low complexity, low power, and low cost, it has been well applied in many fields from computers and electric equipments to household electrical appliances and even telemedicine. This paper first introduced the Bluetooth technology and its application at present and in the future, especially in the telemedicine. And then a potential application in the wireless telemedicine is introduced. That's wireless HOLTER applied by the Bluetooth technology. As HOLTER until now is only limited to do some analyze work based on electrocardiogram, small store capacity and not support long distance communication, the new HOLTER applied by Bluetooth technology can support the live communication which can do a good favor to doctor and patient. [ABSTRACT FROM AUTHOR]

More than eight million people develop active tuberculosis (TB) every year, and about two million die, with more than 90% of global TB cases and deaths occurring in the developing world. DOTS, a program to control TB based on diagnosis and treatment of infectious cases and incorporating the essential management tools has been promoted by WHO as a global strategy since the mid-1990s. While countries applying DOTS on a wide scale have witnessed remarkable results, most developing countries have been unable to expand DOTS as rapidly as needed. Several reasons cited include poor health system organization and TB managerial capability, poor quality and irregular supply of anti TB drugs, and lack of information. This paper describes the preliminary design for a community telemedicine system as an aid in TB treatment and surveillance management, especially in developing countries. The design aims to provide an integrated information system framework to assist TB treatment in accordance to DOTS. It will include software modules for (i) patient treatment surveillance data recording and reporting, (ii) general epidemiology & statistical data recording & reporting, (iii) case finding, diagnostic tool & laboratory examinations, (iv) medication-and-supplies inventory and distribution, (v) personnel training as well as (vi) community education & environment conditioning. The system will use on-location existing telecommunication networks (i.e. internet, GSM, phone line, according to location availability) and telemedicine would be utilized for transfer of healthcare report data, telediagnosis, management of medication distribution and teleeducation. We expect to conduct pilot experimentation in cooperation with the Bandung local health office and Community Health Centres, which are also implementing the DOTS program. In the future, it is hoped the information system can also be a template to develop similar integrated systems for other health issues (i.e. other disease treatment, management of outbreaks, disaster, and other healthcare issues). [ABSTRACT FROM AUTHOR]

Although there are many efforts for automated semantic web service composition, most of them are based upon the traditional AI planning techniques. Openness and dynamics of the Web environment limits the usage of previous approaches based upon the traditional AI planning techniques. This paper introduces a BDI agent system for semantic web service composition and invocation. Through some tests on healthcare web services, we found our BDI agent approach has the potential enough to improve robustness and flexibility of semantic web services. [ABSTRACT FROM AUTHOR]

In the future of super aging society, it is predicted that the problem of disuse dementia becomes more serious all over the world. The screening is very important medical procedure for recovery. In Japan, KANA Pick-out Test(KPT)1-2) have been used as the most useful method of screening. As KPT isn't suitable for internationalization and self-screening, Color Meaning and Matching Test(CMMT) was invented first3), and Color Word Pick-out Test(CWPT)4) follows as an advanced method. In this paper, the sensitivity of CWPT on the basis of KPT was measured as the first evaluation. As the second evaluation, the work of prefrontal lobe was examined during the tests using a near infrared spectroscopy. These evaluations are led to appropriateness of CWPT to the screening test of early dementia. [ABSTRACT FROM AUTHOR]