The Journal of Korean Institute of Communications and Information Sciences (한국통신학회논문지)

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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Heartbeat Detection based on Signal Reflected from Antenna in Mobile Device

휴대기기에서의 안테나 반사 신호를 이용한 심박 신호 검출

  • 안용준 (연세대학교 전기전자공학부 ACEM(Advanced Computational Electromagnetics)연구실) ;
  • 윤기호 (성결대학교 정보통신공학부) ;
  • 육종관 (연세대학교 전기전자공학부 ACEM(Advanced Computational Electromagnetics)연구실)
  • Received : 2013.04.29
  • Accepted : 2013.07.23
  • Published : 2013.07.31
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Abstract

In this paper, human heartbeat detection using signal reflected from the antenna which is varied reflection coefficient by near field variation of the antenna. For detection reflected signal from antenna, 20 dB directional coupler is used because of not affecting transmitting signal. Variance of reflection coefficient of dipole antenna is about 0.07 dB which is too small the distinction between heartbeat and noise. Sensitivity increasing method is applied and heartbeat is clearly detected. Due to phase and magnitude errors come from discrete value components, antenna is located some points in experiments ro find optimum sensitivity position. And providing verification of using communication signal, heartbeat detection when frequency modulated signal which have 4 MHz bandwidth is applied.

본 논문에서는 무선통신기기에서 필수적으로 사용되는 안테나의 근접 전자기장 변화에 의한 반사계수의 변화를 토대로 하여 사람의 심박신호를 검출한다. 반사되는 신호를 검출하기 위하여 20 dB의 directional coupler를 사용하여 송신신호에 영향을 주지 않고 안테나의 반사계수를 검출하는 회로를 사용하였다. 사람의 심박에 의한 다이폴 안테나의 반사계수는 약 0.07 dB 가량 변하게 되어 검출하기 어려우므로, 민감도를 향상시키는 방법을 적용하여 심박신호를 깨끗하게 잡아내었다. Discrete한 소자의 사용으로 오차가 발생하는 것을 감안하여 안테나의 위치를 움직여 최적 지점에서 더 좋은 심박신호의 결과를 나타내는 것을 확인하였고, 일반적인 통신신호에서도 가능한지 확인하기 위하여 4 MHz 대역의 FM신호를 사용하여 잘 동작하는 것을 검증하였다.

Keywords

References

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