Chuang-Chien Chiu

A novel approach based on computerized image analysis for traditional Chinese medical diagnosis of the tongue

This research is aimed at building a computerized tongue examination system (CTES) based on computerized image analysis for the purpose of quantizing the tongue properties in traditional Chinese medical diagnosis. The chromatic algorithm is developed to identify the colors of the tongue and the thickness of its coating. The textural algorithm is used to detect the grimy coating. CTES is shown to be significantly consistent within itself with P > 0.05 using the Hotelling multivariate statistical test. The overall rate of correctness for CTES to identify the colors of tongue, verifying the thickness of its coating and detecting of any grimy coating exceeds 86%. Therefore, the CTES is helpful to provide the physicians a systematic and objective diagnostic standard for the tongue diagnosis in the clinical practice and research.

A Novel Personal Identity Verification Approach Using a Discrete Wavelet Transform of the ECG Signal

The purpose of this research is to develop a real time system for individual verification with the electrocardiogram (ECG) signal. The ECG signal varies from person to person and it can be used as a new biometric for individual verification. The discrete wavelet transform extract signal features by wavelet coefficients of one-lead ECG signal. Using the proposed approach on 35 normal subjects and 10 arrhythmia patients, 100% verification rate was obtained for normal subjects and 81% verification rate for arrhythmia patients. Furthermore, the performance of the ECG verification system was evaluated by the false acceptance rate (FAR) and false rejection rate (FRR). The FAR was 0.83% and FRR was 0.86%for a database containing only 35 normal subjects. When 10 arrhythmia patients were added into the database, the FAR became 12.50% and the FRR 5.11%. The experimental results demonstrate that the proposed system works very well for normal subjects.

USING CORRELATION COEFFICIENT IN ECG WAVEFORM FOR ARRHYTHMIA DETECTION

Arrhythmia is one kind of diseases that gives rise to the death and possibly forms the immedicable danger. The most common cardiac arrhythmia is the ventricular premature beat. The main purpose of this study is to develop an efficient arrhythmia detection algorithm based on the morphology characteristics of arrhythmias using correlation coefficient in ECG signal. Subjects for experiments included normal subjects, patients with atrial premature contraction (APC), and patients with ventricular premature contraction (PVC). So and Chans algorithm was used to find the locations of QRS complexes. When the QRS complexes were detected, the correlation coefficient and RR-interval were utilized to calculate the similarity of arrhythmias. The algorithm was tested using MIT-BIH arrhythmia database and every QRS complex was classified in the database. The total number of test data was 538, 9 and 24 for normal beats, APCs and PVCs, respectively. The results are presented in terms of, performance, positive predication and sensitivity. High overall performance (99.3%) for the classification of the different categories of arrhythmic beats was achieved. The positive prediction results of the system reach 99.44%, 100% and 95.35% for normal beats, APCs and PVCs, respectively. The sensitivity results of the system are 99.81%, 81.82% and 95.83% for normal beats, APCs and PVCs, respectively. Results revealed that the system is accurate and efficient to classify arrhythmias resulted from APC or PVC. The proposed arrhythmia detection algorithm is therefore helpful to the clinical diagnosis.

Design of a computer game using an eye-tracking device for eye's activity rehabilitation

An eye mouse interface that can be used to operate a computer using the movement of the eyes is described. We developed this eye-tracking system for eye motion disability rehabilitation. When the user watches the screen of a computer, a charge-coupled device will catch images of the users eye and transmit it to the computer. A program, based on a new cross-line tracking and stabilizing algorithm, will locate the center point of the pupil in the images. The calibration factors and energy factors are designed for coordinate mapping and blink functions. After the system transfers the coordinates of pupil center in the images to the display coordinate, it will determine the point at which the user gazed on the display, then transfer that location to the game subroutine program. We used this eye-tracking system as a joystick to play a game with an application program in a multimedia environment. The experimental results verify the feasibility and validity of this eye-game system and the rehabilitation effects for the users visual movement.

DISCRETE WAVELET TRANSFORM APPLIED ON PERSONAL IDENTITY VERIFICATION WITH ECG SIGNAL

The main purpose of this study is to present a novel personal authentication approach with the electrocardiogram (ECG) signal. The electrocardiogram is a recording of the electrical activity of the heart and the recorded signals can be used for individual verification because ECG signals of one person are never the same as those of others. The discrete wavelet transform was applied for extracting features that are the wavelet coefficients derived from digitized signals sampled from one-lead ECG signal. By the proposed approach applied on 35 normal subjects and 10 arrhythmia patients, the verification rate was 100% for normal subjects and 81% for arrhythmia patients. Furthermore, the performance of the ECG verification system was evaluated by the false acceptance rate (FAR) and false rejection rate (FRR). The FAR was 0.83% and FRR was 0.86% for a database containing only 35 normal subjects. When 10 arrhythmia patients were added into the database, FAR was 12.50% and FRR was 5.11%. The experimental results demonstrated that the proposed approach worked well for normal subjects. For this reason, it can be concluded that ECG used as a biometric measure for personal identity verification is feasible.

Objective assessment of blood stasis using computerized inspection of sublingual veins.

In traditional Chinese tongue diagnosis, inspection of the sublingual veins has been developed as a new diagnostic examination method especially for determining blood stasis. The main purpose of this research is to develop a computerized inspection system, used to quantitatively extract the chromatic and geometrical properties of sublingual veins. A method based on color equalization is presented to assist the image segmentation of sublingual veins. Color image analysis techniques are applied to extract the length, width, area and color information from sublingual veins. Experimental results are compared with the visual inspection of physicians. The severity of blood stasis was classified into three groups: normal, moderate and pronounced. Each group consisted of eight subjects. The overall recognition rate is 87.5% in the leaving-one-out classification using the developed system.

Assessment of cerebral autoregulation using time-domain cross-correlation analysis.

Time domain cross-correlation analysis of pre-filtered mean arterial blood pressure (MABP) and mean cerebral blood flow velocity (MCBFV) was applied to assess the cerebral autoregulation (CA). Beat-to-beat time series of spontaneous arterial blood pressure and cerebral blood flow velocity were obtained from 13 young normal volunteers with the Finapres device and the transcranial Doppler for periods of approximately 5 min in the supine position. Cross-correlation functions (CCFs) were estimated using a 64 beat wide moving window. Mean CCF patterns were obtained for each subject and for the entire population. The MABP and MCBFV signals were bandpass filtered in the very low-frequency range (VLF, 0.015-0.07 Hz), low-frequency range (LF, 0.07-0.15 Hz) and high-frequency range (HF, 0.15-0.40 Hz) before applying CCF for the purpose of studying the effect of different bandwidths on the resulting mean CCFs. Results revealed that the corresponding time lags of the peak values of the MABP-MCBFV CCFs increased significantly between the LF and HF frequency ranges (LF: -1.20+/-0.91 s, HF: -0.07+/-0.42 s,p < 0.001; paired sign test). The left-shift (negative lag) of the CCF peak between MABP and MCBFV is a result of the phase-lead property. The increasing time lag of the CCF peak indicated evidence of the autoregulatory disturbance. The CCF of pre-filtered spontaneous MABP and MCBFV could be a useful tool to estimate the CA dynamic response.

Objective auscultation for traditional Chinese medical diagnosis using novel acoustic parameters

The goal of this work is to propose novel acoustic parameters of voice for the purpose of providing a quantitative analysis of auscultation in traditional Chinese medical diagnosis. There is rare amount of available literature related to this topic. Four novel acoustic parameters, the average number of zero-crossings, the variations in local peaks and valleys, the variations in first and second formant frequencies, and the spectral energy ratio, are presented to analyze and identify the characteristics among non-vacuity, qi-vacuity, and yin-vacuity subjects. Among these acoustic parameters, two temporal parameters, the average number of zero-crossings and the variations in local peaks and valleys, outperformed other parameters in classifying both non-vacuity and deficient subjects. The spectral energy ratio was adequate for the classification between qi-vacuity and yin-vacuity patients. This research is a first step in an ongoing effort to modernize the auscultation in traditional Chinese medical diagnosis.

Variations of HRV analysis in different approaches

The analysis of normal-to-normal (NN) intervals acquired from a continuous electrocardiogram (ECG) record is a standard method to evaluate the variations in heart rate. For the advantage of responding to the pumping action of the heart, photoplethysmography (PPG) has also been used extensively in the analysis of heart rate variability (HRV). However, there is little literature available on the variation between the HRV analysis derived from ECG and PPG. In the research described here, experiments of recording short-term (les 5 minutes) ECG and PPG signals simultaneously from healthy subjects (male, N=10) under control were carried out to investigate the possibility of such variation. Automatic computer analysis is provided for the analysis of correlation coefficient and the LF/HF ratio by autoregressive (AR) spectral analysis for evenly resampled sequences. The identical results are highly expected. However, the correlation coefficient between RRI (R-R interval from ECG) and PPI (peak-to-peak interval from PPG) is 0.86plusmn0.15, which should be unity for perfectly matched patterns. In additions, the relative LF/HF ratios are 2.49plusmn1.13 (for ECG) and 2.73plusmn0.82 (for PPG) respectively. Though there is no statistical difference, the worst likelihood ratio (LR) reaches the deviation of 19.04%. From the experimental results, it can be appreciated that there is indeed variation for HRV analysis in two different approaches even for healthy subjects under well-controlled conditions. For abnormal subjects in clinical applications, such variation may be expected to become more apparent. Though the variation is minor, it is suggested to obey the standard measure of HRV proposed by Task Force for consistent conclusions.

Self-organizing arterial pressure pulse classification using neural networks: theoretical considerations and clinical applicability

A self-organizing classification system for the arterial pressure pulse based on the ART2 (adaptive resonance theory) network was developed. The system consists of a preprocessor and an ART2 recognition network. The preprocessor removes the arterial pressure pulse servo component signals from Finapres, detects the systolic pressure points and divides the acquired signals into minimal cardiac cycles. The ART2 network input is the minimal cardiac cycle detected by the preprocessor. The classification results can be used to assist physicians in evaluating the signs of abnormal and normal autonomic control and has shown its clinical applicability for the examination of the autonomic nervous system.