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A Design of EMD-based Filter to Remove Motion artifacts in Wireless ECG Monitoring 1 Hae-KyungJung, 2 Yun-hong Noh, 3 Do-un Jeong 1, First Author Graduate School of Ubiquitous IT, Dongseo University, Busan, Korea, [email protected] 2 Division of C omputer & Information Eng ineering, Dongseo Univ ersity, Busan, Kor ea, [email protected] *3, Corresponding Author Division of C omputer & Information Eng ineering, Dongseo Uni versity, Busan, Kore a, dujeong @gdsu.dong seo.ac.kr Abstract Motion artifac t distorted EC G signal is a commonl y known issue in mobile ECG re cording. In this paper, we present a better method to replace existing filtering technique while preserving distortion free ECG si gnal. A bel t-type EC G measuremen t system to measure ECG signal in daily life has been d eveloped . A 3-axis acc eleromete r sensor is insta lled on the EC G measurement system to obtain activity data. Activity status is classified using fuzzy rule base classifier. Then an optimal adaptive filter using empirical mode decomposition, EMD is proposed for motion artifact removal. EMD is used to decompose motion artifact from the ECG signal and finally preserve a distortion free EC G signal at the end of the result . Keywords: u-Healthcare, Motion artifact, ECG, Bio-Signal Measurement System 1. Introduction In recent years, the number of elderly group is growing rapidly in South Korea and various local research efforts has been put on into medical technology to improve the life spent. The medical cost for elder people is high and therefore disease management for elderly group is seen to be a challenge. Therefore, a low cost, relax and secure medical service has become the demand for future healthcare. Nevertheless, ubiquitous healthcare t echnology will pick u p t he l eading rol e in the field of healthcare industry. ECG signal being a biometric parameter which provides essential clinical information for chronic diagnosis. ECG signal monitoring by using mobile device is therefore being extensively studies in literature. Unfortunately, motion artifact that incurred due to body movement which distorts ECG signal badly is a critical challenge in daily life ECG monitoring or recording. The most common technique used for motion artifact removal is to use a high-pass filter to absolutely reject low frequency component since motion artifact incurred at low frequency band. However, in real time practice, motion artifact underlay throughout the ECG signal band of interest but not only in low frequency band. Therefore, removing low frequency component by using high pass filter coefficient seems to be a non-optimum solution for practical motion artifact removal. In this paper, a chest- belt ECG instrumentation system mounted with 3-axis accelerometer has been designed and implemented. Activity status is classified by using fuzzy rule-based classifier. Since motion artifact is incurred at difference frequency band, we use empirical mode decomposition EMD to decompose motion artifact from ECG signal. Theoretically, noise signal (motion artifact) at difference frequency band can be extracted by using EMD and thus a clean and distortion free ECG signal can be preserved. In this paper, we proved our proposal with practice and the result is promising. In the presence of body movement, the success rate of heart beat detection has been significantly improved. 2. Method 2.1. Wearable wireless ECG measurement system A Design of EMD-based Filter to Remove Motion artifacts in Wireless ECG Monitoring Hae-KyungJung, Yun-hong Noh, Do-un Jeong Journal of Convergence Information Technology(JC IT) Volume8, Number11, June 2013 doi:10.4156/jcit.vol8.issue11.74 660
