Seok Myung Jung

Wearable ECG Monitoring System Using Conductive Fabrics and Active Electrodes

The aim of this paper is to develop nonintrusive type ECG monitoring system based on active electrode with conductive fabric. Our developed electrode can measure ECG signal without the electrolyte gel or the adhesives causing skin trouble. For the stable measurement of ECG signal, the buffer amplifier with high input impedance and the noise bypassing shield with conductive fabric were developed. This system involves real-time ECG signal monitoring, and wireless communication using the Zigbee protocol. We show experimental results for developing wearable ECG monitoring system and demonstrate how it can be applied to the design of nonintrusive electrode with conductive fabric.

Prototype design of mobile emergency telemedicine system

High bit rate wireless cellular service using CDMA 1X-EVDO is now popular in Korea, particularly in urban areas, since it was launched commercially in 2002. This cellular service allows the real-time transmission of patient images and vital sign signals simultaneously in a moving ambulance application. In this paper, we designed a prototype emergency telemedicine system that can transfer both biological signal and patient motion video from a moving vehicle using a CDMA 1X-EVDO reverse link. To cope with the limited bandwidth of the reverse link (transmission bandwidth of cellular device) relative to the the forward link (receiving bandwidth), priority control between the vital sign and video images, frame rate control using MPEG-4 compression, and error control using automatic repeat request were incorporated into the application layer protocol of the designed prototype system. Many on-road experiments have been performed to evaluate the actual performance and to demonstrate the applicability in a real situation. In most cases, the biological signal and patient video images with reduced frame rate were successfully transmitted from the moving vehicle in urban areas.

Integrated mobile terrestrial digital multimedia broadcasting player compliant with the T-DMB, CMMB, and ISDB-T standards

In this paper, we designed an integrated mobile terrestrial Digital Multimedia Broadcasting (DMB) player. The newly designed DMB player provides audio and video displays in accordance with the T-DMB, CMMB, and ISDB-T standards. In order to support displaying audio and video stream data of these three different standards selectively, we developed a unified Transport Stream (TS) parser, implemented new DMB player applications that provide the necessary functionalities and menus. In the near future users of this new terrestrial DMB player will be able to receive mobile terrestrial DMB data as they travel in Korea, China and Japan without the need of a corrective DMB receiver device for each country.

Development of Mobile Ad Hoc Network for Emergency Telemedicine Service in Disaster Areas

Emergency Telemedicine Service (ETS) is used efficiently for treatment to the wound patient in disaster areas. However, ETS cannot be used if the primary network channel is unavailable due to unexpected damages on the communication infrastructures, and increased network traffics. We established the Mobile Ad hoc Network (MANET) based on Wireless LAN (WLAN), and developed software program implemented with the Ad hoc On-Demand Distance Vector Routing Algorithm. The results of experiment are shown that a Mobile Node (MN) in disaster areas provided the sufficient network bandwidth for ETS using MANET. Therefore, MANET is able to provide the ETS by supple configuring the secondary channel in disaster areas where the primary network channel is unavailable.

Performance evaluation of the electrode configuration in bioelectrical impedance analysis for visceral fat measurement

Excessive amount of visceral fat is considered as a crucial indicator for the metabolic syndrome (MS). Visceral fat area (VFA) at the umbilicus level measured by CT is adopted as the gold standard, but it has many limitations. Recently, Application of bioelectrical impedance analysis (BIA) for measuring VFA is widely used. However, the correlation between impedance and VFA is highly dependent on the measurement conditions. Therefore, we evaluate its measurement conditions here. In our experiment, we choose 5 different electrode configurations with changes of current and its frequency for evaluating its performance to distinguish fat and thin group with impedance. Our results indicated that electrode arrangement with fixed waist ratio is better in its performance than fixed distance electrode arrangement. Current electrode on each flank side is better than on the front and rear side. Shorter distance between current electrode and voltage electrode is better than longer distance in its performance. Our experiment results are presented.

Novel A/V synchronization method for portable T-DMB players supporting BIFS

In this study, we implemented an enhanced A/V synchronization method including BIFS processing for new portable T-DMB players. The T-DMB supports simultaneous audio, video, and BIFS transmission. However, delayed correction or non-correction of the audio and video synchronization can be annoying to the user. Here, a novel synchronization strategy is applied for video, audio, and BIFS using a control buffer. The proposed method preferentially synchronizes audio data with an internal clock system and performs resynchronization by comparing audio CTS signal with video CTS signal. The designed system could complete the synchronization of audio and video including BIFS data, thus allowing stable T-DMB services in unreliable transmission environments such as shadow regions.