@inproceedings{c31fe858c5f141b4bace0e2fd5efe799,
title = "Sensitivity enhanced noncontact vital signal sensor using oscillation frequency deviation",
abstract = "In this paper, a 2.4 GHz wireless vital signal sensor is proposed to detect heartbeat and respiration signals. The oscillator circuit incorporates with the planar resonator, which functions as a parallel feedback element as well as a near-field radiator. The periodic movement of a body by respiration exercise could cause the input impedance variation of the radiator within near-field range. This variation results in corresponding deviation in the oscillation frequency and it has been utilized for sensing of vital signals. In addition, a SAW filter and power detector have been used to transform the frequency variation into voltage waveform. Also, the relation of the frequency deviation of oscillator and the Q value of resonator is analyzed to increase the system sensitivity. As a result, the experimental results show that the proposed sensor placed 10 mm away from a human body can detect the vital signals very accurately.",
keywords = "Parallel feedback oscillator, planar resonator, vital signal sensor, wireless sensor",
author = "Kim, {Sang Gyu} and Yoon, {Gi Ho} and Yook, {Jong Gwan}",
year = "2011",
language = "English",
isbn = "9780858259744",
series = "Asia-Pacific Microwave Conference Proceedings, APMC",
pages = "1586--1589",
booktitle = "Asia-Pacific Microwave Conference Proceedings, APMC 2011",
note = "Asia-Pacific Microwave Conference, APMC 2011 ; Conference date: 05-12-2011 Through 08-12-2011",
}