A Study on Signal Analysis of the Data Aquisition System for Photosensor

The major advantage of slip-ring technology in Spiral CT is that it facilitates continuous rotation of the x-ray tube, so that volume data can be acquired from a patient quickly. Not only for such a fast scan, but also for the dose reduction purpose, high signal-to-noise ratio and fast data acquisition system is required. In this study, we have built a multi-channel photodetector and multi-channel data acquisition system for CT application. The detector module consisted of CdWO4 crystal and Si photodiode in 16 channels. For the performance test of the preamplifier stage, both the transimpedance and switched integrator types are optimized for the photodetector modules. Switched integrator showed better noise performance in the limited bandwidth which is suitable for the current CT application. The control sequence for data acquisition and 20 bit ADC is designed with VHDL(Very High Speed Integrated Circuit Hardware Description Language) and implemented on FPGA(Field Programmable Gate Array) chip. Our Si photodiode detector module coupled to CdWO4 crystal showed comparable signal with other commercially available photodiode for CT. Switched integrator type showed higher SNR but narrower bandwidth compared to transimpedance preamplifier. Digital hardware is designed by FPGA, so that the control signal could be redesigned without hardware alteration.ope

Recognition of Negative Emotion using Long Short-Term Memory with Bio-Signal Feature Compression

Negative emotion is one reason why stress causes negative feedback. Therefore, many studies are being done to recognize negative emotions. However, emotion is difficult to classify because it is subjective and difficult to quantify. Moreover, emotion changes over time and is affected by mood. Therefore, we measured electrocardiogram (ECG), skin temperature (ST), and galvanic skin response (GSR) to detect objective indicators. We also compressed the features associated with emotion using a stacked auto-encoder (SAE). Finally, the compressed features and time information were used in training through long short-term memory (LSTM). As a result, the proposed LSTM used with the feature compression model showed the highest accuracy (99.4%) for recognizing negative emotions. The results of the suggested model were 11.3% higher than with a neural network (NN) and 5.6% higher than with SAE.ope

Evaluation Factors of Clinical Decision Support System in u_Healthcare Service

Automated intelligent, clinical decision support systems generally promote to help or to assist physicians and patients regarding to prevention of diseases or treatment of illnesses using computer represented knowledge and information. In this paper, assessment factors affecting the proper design of clinical decision support system were investigated. The required procedure steps for gathering the data from clinical trial and extracting the information from large volume of healthcare repositories were listed, which are necessary for validation and verification of evidence-based implementation of clinical decision support system. The goal of this paper is to extract useful evaluation factors affecting the quality of the clinical decision support system in the design, development, and implementation of a computer-based decision support system.ope

Web-Based Asthma Care System

Asthma is a chronic disease, which requires a successive and long-term management. In this paper, we implemented a web-based caring system for a more effective management of the asthmatics. The service of this asthmatic-caring system targeted on both the doctor and the patient. The patient connects to the asthma management server through the Internet everyday and inputs his or her daily condition and dosage. Then the doctor will give a proper comment or order to the patient according to the data that patient has filled in. By merely connecting to this web-site, doctors can manage asthmatics everyday and the patient can be under the doctor’s management without frequently visiting the hospital. The test verifying the user’s satisfaction of the implemented system has been taken by both the doctor- and the patient-groups. The doctor-group pointed out the successive management, an easy inspection of the patient condition, and the accumulation of clinical data for future researches as advantages. The patientgroup pointed out being under the daily management without visiting hospital and the active attitude they can have toward their diseases as advantages.ope

Feature Selecting Algorithm Development Based on Physiological Signals for Negative Emotion Recognition

Emotion is closely related to the life of human, so has effect on many parts such as concentration, learning ability, etc. and makes to have different behavior patterns. The purpose of this paper is to extract important features based on physiological signals to recognize negative emotion. In this paper, after acquisition of electrocardiography(ECG), electroencephalography(EEG), skin temperature(SKT) and galvanic skin response(GSR) measurements based on physiological signals, we designed an accurate and fast algorithm using combination of linear discriminant analysis(LDA) and genetic algorithm(GA), then we selected important features. As a result, the accuracy of the algorithm is up to 96.4% and selected features are Mean, root mean square successive difference(RMSSD), NN intervals differing more than 50ms(NN50) of heart rate variability(HRV), σand α frequency power of EEG from frontal region, α, β, and γfrequency power of EEG from central region, and mean and standard deviation of SKT. Therefore, the features play an important role to recognize negative emotion.ope

Spatio-Spectral Coherence Analysis of ERP signals for Attentional Visual Stimulus

In this paper, the brain function in relation with human’s visual attention was investigated by means of coherence and bicoherence methods. Throughout experimentation with attentional visual stimulus ERP (Event Related Potential) data and synthesized simulated data with different combinations of parameters, it is demonstrated that bicoherence and coherence can be useful to reveal the phase synchronies between different frequency bands at fixed scalp location, and between different scalp locations at fixed frequency band, respectively. Both methods are also affected by time interval from the onset, and the level of white noise added. The phase coupled relationships among θ, δ, and α bands, and between frontal and central lobes were observed for attentional tasks, while those were little observable for inattentional tasks, which can show brain’s functional spatio-spectral differences associated with human’s attention.ope

A study on performance evaluation for Electrocardiography signal measurement electrode based on conductive fabric

Recently, as we move toward a society with an increasingly aged population, wearable U-health devices in various shapes with smart wear have been developed in order to conveniently measure health variables without using hands in daily life or at home. However, the problem is that only supply of the wearable U-health devices is focused and its applicable devices are studied and developed, which has resulted in lack of awareness of importance of performance evaluation. In this study, two electrodes were fabricated using conductive fabric which can be used as electrode if attached to wearable U-health devices or smart wear in order to measure ECG signal. Two electrodes those were fabricated using conductive fabric were compared the correlation, impedance and CMRR with patch typed Ag-AgCl electrode-normally used for measurement of ECG signal, so that the study would find out if the fabricated electrode can be used with the wearable U-health devices by testing and evaluating performances.ope

The Design of Feature Selection Classifier based on Physiological Signal for Emotion Detection

The emotion plays a critical role in human’s daily life including learning, action, decision and communication. In this paper, emotion discrimination classifier is designed to reduce system complexity through reduced selection of dominant features from biosignals. The photoplethysmography(PPG), skin temperature, skin conductance, fontal and parietal electroencephalography(EEG) signals were measured during 4 types of movie watching associated with the induction of neutral, sad, fear joy emotions. The genetic algorithm with support vector machine(SVM) based fitness function was designed to determine dominant features among 24 parameters extracted from measured biosignals. It shows maximum classification accuracy of 96.4%, which is 17% higher than that of SVM alone. The minimum error features selected are the mean and NN50 of heart rate variability from PPG signal, the mean of PPG induced pulse transit time, the mean of skin resistance, and δ and β frequency band powers of parietal EEG. The combination of parietal EEG, PPG, and skin resistance is recommendable in high accuracy instrumentation, while the combinational use of PPG and skin conductance(79% accuracy) is affordable in simplified instrumentation.ope

Design of Wired/Wireless Integrated Medical Information Management System Based on Web Service

Objective: According to development of web service technology and mobile device supply, mobile web service becomes an essential element of ubiquitous healthcare. But there are many constraints for offering mobile web services on mobile devices. Hence, this paper propose optimal system supplying web services about medical information in wired /wireless network according to resources of device. Methods: Proposed system consists of web server, database, desktop subscriber, mobile device and mobile context server. When a mobile device requires the web service, a mobile context server rewrites and offers the equivalent contents provided from web server to suit the requiring device's resource. Our proposed system services the same medical information after its recomposition as the network and devices of user. Results: The medical staff may require patient information in wired/wireless environment, web server and mobile context server supports their correct judgment and expeditious response by servicing optimized data of the patient according to the requiring device. Conclusion: Proposed system designed the wired/wireless integrated medical information system using web service and mobile web service as the bases of ubiquitous healthcare system. Not only for web service in wired network, to provide the optimal web service in wireless network, we should know the limited resource of mobile devices and appropriately divide the web contents of wired network to fit the mobile device's screen. The future research needs dynamic division of screen according to extension of medical information data.ope

Enhancement of Evoked Potential Waveform using Delay-compensated Wiener Filtering

In this paper, the evoked potential(EP) was represented by additive delay model to comply with the variational noisy response of stimulus-event synchronization. The hybrid method of delay compensated-Wiener filtered-ensemble averaging(DWEA) was proposed to enhance the EP signal distortion occurred during averaging procedure due to synchronization timing mismatch. The performance of DWEA has been tested by surrogated simulation, which is composed of synthesized arbitrary delay and arbitrary level of added noise. The performance of DWEA is better than those of Wiener filtered-ensemble averaging and of conventional ensemble averaging. DWEA is endurable up to added noise gain of 7 for 10 % mean square error limit. Throughout the experimentation observation, it has been demonstrated that DWEA can be applied to enhance the evoked potential having the synchronization mismatch with added noise.ope