Hyoung-Ro Yoon

Gram-Schmidt M-Wave Canceller for the EMG Controlled FES

To use the voluntary electromyogram (EMG) as a control signal of the EMG controlled functional electrical stimulator (FES), it is required to reduce the stimulation artifact and non-voluntary contribution (M-wave). In this study, a Gram-Schmidt (GS) prediction error filter (PEF) that can effectively eliminates the M-wave from voluntary EMG is presented. Also, the presented GS PEF is implemented on the field the programmable gate array (FPGA) for real-time processing and the performance is tested with simulated and real signals. Experimental results showed that GS-PEF was effective in reducing M-wave and preserving voluntary EMG.

Upiquitous Home Healthcare Management System with Early Warning Reporting

The changes of medical environments such as the growth of a patient with a chronic disease and the elderly, and the advance of the IT technology require highly qualified medical service of new paradigm. For the reason, home health management service has been focused with much expectations and interests. Our proposed home health management system (H2MS) monitors and manages daily physiological status which is easily acquired from multiple-sensor based ubiquitous bio-signal sensor during sleeping, bathing, evacuating, and living at home. H2MS is largely consisted of four functional subsystems: multiple-sensor based ubiquitous bio-signal sensor, home health intermediary client (H2IC), home health center (H2C), and home health service provider (H2SP). Each subsystem carried out their own processes and collaborated on a work with each other. H2MS provides various home health services for the wellness, as well as the elderly, chronic patients illness, or terminal illness. Also, it is available to suggest various services: an early warning service according to the change of health status, advice service for health improvement, and appointment service for medical treatment. Moreover, this early warning service makes promptly emergency repairs as soon as occurrence of physiologically abnormal symptom. Consequently, early warning reports reduce the frequent intervention of high costed service of medical professionals.

Automatic vital signals measurement system attached in lavatory in ubiquitous healthcare environment

The system proposed in this paper has been designed to acquire and transmit vital signals from lavatory-attached acquisition device in ubiquitous healthcare environment. We focused on the system to be unconstrained and noninvasive by introducing automative measurement procedures. ECG, SpO2, BP, Bio-impedance and weight are measured and recorded. Users can check their present basic health information through the monitor beside lavatory as soon as completing each of procedures. All of the data set acquired are transmitted to main sever system located in healthcare-provider such as general hospital, public health center, etc via commercial network as well as classified and scored according to physiologically well-known criteria with a waterproof computer terminal. Early classification of individual data into normal, abnormal and emergency state just after measurement complete is very helpful to draw up in order among enormous data from many users both manageably and technically.

Development and Evaluation of an Improved Algorithm for Detection of Ventricular Fibrillation

Our study focuses on a development and evaluation of ventricular fibrillation detection algorithm included clinical considerations on electrocardiography(ECG) signals as real-time warning on ventricular fibrillation occurrence in patients, especially at ICU and CCU is most critical function of a patient monitoring system. To determine whether ECG signal contains features on ventricular fibrillation, first, bandpass filter was applied, then peaks and valleys were detected in recent 2 seconds by 0.5second interval. Finally, time-difference and amplitude variation on both peaks and valleys and mutual relation on time difference between peak and valley were computed. These computed values allow us to decide whether ventricular fibrillation occurs or not. Moreover, we separated cardiac pulsation state into heartbeat, asystole and ventricular fibrillation state respectively so as to transfer one state to another state if present state did not meet the requirements established for each state. We conducted an assessment of performance of our proposed algorithm. Test signals were taken from the AHA ECG Database Series I and MIT-BIH Arrhythmia Database. As a result, VF duration sensitivity and VF duration positive predictivity is 98.1% and 99.1% in AHA DB, 88.5% and 86.3% in MIT-BIH DB respectively.

Estimation and evaluation of whole body fat mass obtained from lavatory-attached system for ubiquitous healthcare

Measurement of body fat mass on lavatory which forms a part of U-Healthcare system based on noninvasive, unconscious, and nonrestrictive method makes it possible to supply optimal nutrition to user and prevent asthenia of muscles and hypertrophy of user body by observing changing patterns of body fat mass for a long term. Also, user can monitor his/her body fat mass and prevent diseases related to obesity and settle problems due to excessive diet. The purpose of this study was to estimate more acceptable fat mass value of whole body from the range which is obtained from lavatory-attached device. We designed lavatory seat to contain two-pairs of electrode in order to make each electrode contact right and left thigh respectively. Electrodes for right hand were included in grip-shaped armrest. To overcome limitation derived from electrodes location, in other words, to take into consideration that impedance of both calf of the leg does not measured, additional factor ‘weight of the legs’ is considered to estimate more accurate value. The estimation equation was developed and compared with conventional body impedance analyzer which electrodes are located at two wrists and two ankles. In conclusion, it was possible to estimate good fat mass of whole body from seating position on lavatory by adding ‘weight of legs’ factor.