Yongwon Jang

Wearable Respiratory Rate Monitoring using Piezo-resistive Fabric Sensor

The experimental results on respiratory rate monitoring using piezo-resistive fabric sensor under various moving environments are presented. As a basic biomedical signal for the healthcare monitoring, it is desirable to measure the respiratory rate even in the rapid running motion besides in the slow walking. We perform the experiment of respiratory rate monitoring using wearable piezo-resistive fabric sensor under various moving environments. In this paper, a preliminary measurement result is reported.

Comparison of conductive fabric sensor and Ag-AgCl sensor under motion artifacts

A wearable electrocardiogram(ECG) device using conductive fabric sensor was compared with traditional Ag-AgCl electrode ECG device. The ECG signals were measured under existence of motion artifacts on variable running speed using treadmill to verify that wearable device can substitute traditional ECG device. A signal to noise ratio (SNR) and RR interval were compared between the two devices. The SNR of wearable device was similar or higher than that of clinical device and difference of RR interval was 2ms. The results show that the wearable ECG device using conductive fabric sensor can make similar performance with ECG device using Ag-AgCl electrode even under motion artifacts.

Development of an integrated obesity management waist belt system composed of calorie tracking and waist circumference measuring module for long term monitoring

A waist belt type simple device was designed to monitor the individuals who are obese and want to maintain their consumed calories and waist circumference changes. Relatively long term monitoring with this device could help them maintain their health conditions. This devised system is composed of calorie tracking and waist circumference module. This study suggests feasible and meaningful results. If users data are collected largely with this developed system, we can reveal the relationship between obesity and daily life pattern.

A basic study for automatic waist circumference measurement using magnet with waist belt to assist obese management in daily life

Waist circumference is a very important factor in deciding if someone has the potential for obesity, but there has been no device that automatically measures waist circumference. In this study, a new waist circumference measurable belt was devised and is accurate to 5mm resolution. The system is comprised of magnets and magneto-resistive sensors to measure waist circumference. A novel algorithm was developed to distinguish the belt moving direction. This belt system can assist in obesity and overweight management and a connection with IT and communication networks may make this system a more powerful tool.Waist circumference is a very important factor in deciding if someone has the potential for obesity, but there has been no device that automatically measures waist circumference. In this study, a new waist circumference measurable belt was devised and is accurate to 5mm resolution. The system is comprised of magnets and magneto-resistive sensors to measure waist circumference. A novel algorithm was developed to distinguish the belt moving direction. This belt system can assist in obesity and overweight management and a connection with IT and communication networks may make this system a more powerful tool.

Sequential algorithm for the detection of the shockable rhythms in electrocardiogram

We suggest a sequential algorithm for the detection of the ventricular fibrillation (VF) and ventricular tachycardia (VT) of a rate above 180 bpm, so called shockable rhythms. The built-in algorithm for ECG analysis embedded in the portable bio-signal sensing module is aimed to discriminate between shockable and non-shockable rhythms and its accuracy is analyzed. An algorithm for VF/VT detection is proposed to analyze every 1 s ECG episode using the past 8 s episodes. The method is tested with 844,587 ECG episodes from the widely accepted databases. A sensitivity of 86.8 % and a specificity of 99.4 % were obtained and compared with the previous results.

Development of a patch type embedded cardiac function monitoring system using dual microprocessor for arrhythmia detection in heart disease patient

A patch type embedded cardiac function monitoring system was developed to detect arrhythmias such as PVC (Premature Ventricular Contraction), pause, ventricular fibrillation, and tachy/bradycardia. The overall system is composed of a main module including a dual processor and a Bluetooth telecommunication module. The dual microprocessor strategy minimizes power consumption and size, and guarantees the resources of embedded software programs. The developed software was verified with standard DB, and showed good performance.

A basic study for patch type ambulatory 3-electrode ECG monitoring system for the analysis of acceleration signal and the limb leads and augmented unipolar limb leads signal

A compact and portable device was designed for preliminary study of patch type ambulatory 3-electrode ECG monitoring system for limb leads and augmented unipolar limb leads signal analysis. The developed system also can measure and send the acceleration signals wirelessly during daily life to analyze the users information. The 3-electrode system is feasible to provide the information of limb leads and augmented unipolar limb leads for further arrhythmia analysis and simultaneously shows lots of issues to be more broadly applicable and more powerful device.

A basic study of activity type detection and energy expenditure estimation for children and youth in daily life using 3-axis accelerometer and 3-stage cascaded artificial neural network.

It is important to prevent obesity in childhood given that many obese adults have been obese since childhood. An activity monitor could provide an effective aid in preventing obesity if it records not only the calorie assessment but also activity detection to check how active a child is in daily life. The current study is for activity monitoring algorithm and we designed 3-stage cascaded artificial neural network. To develop the algorithm, we recruited 76 participants, made 3-axis accelerometer for them, and acquired activity data and calorie consumption data through them. Finally, we designed 3-stage cascaded network to classify the activities and to assess energy consumption. The 3-stage network classifies 4 activities of walking, running, stairs moving, and jumping rope with overall accuracy of 94.70%, and predicts calorie consumption with average accuracy of 81.91%, which is better than the results of the 2-stage network. Future work would include the enhancement of the network performance.

A preliminary study of the effect of electrode placement in order to define a suitable location for two electrodes and obtain sufficiently reliable ECG signals when monitoring with wireless system

Most countries face high and increasing rates of cardiovascular disease. Each year, heart disease kills more Americans than cancer. Therefore, there has been a promising market for portable ECG equipment and it is increasing. To use portable ECG measuring devices, it is essential to define a suitable location for the measuring as we need to reduced electrode size and distance. This research proposes to study how the inter-electrode distance affects the signal and how the electrode pair should be placed on the chest in order to obtain a sufficiently reliable ECG signal to detect heart arrhythmias in any environment, such as home or work. Therefore, we developed a compact, portable patch type ambulatory ECG monitoring system, Heart Tracker, using a microprocessor for preliminary study of signal analysis. To optimize the electrode arrangement in wireless environment, we compared HT and standard 12 lead with changing electrode position.