Compact vital signal sensor using oscillation frequency deviation

Sang Gyu Kim, Gi Ho Yun, Jong Gwan Yook

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

In this paper, a compact vital signal sensing method using oscillation frequency deviation at 2.4-GHz industrial-scientific-medical band is proposed to detect vital signals, such as heartbeat and respiration signal. The oscillation circuit of the proposed vital sensor system has been realized by a planar resonator, which functions as a positive feedback element, as well as a near-field radiator to sense vital signals, simultaneously. The periodic movement of a body by respiration exercise causes the impedance variation of the radiator within the near-field range. The impedance variation results in a corresponding change in the oscillation frequency, and this variation has been utilized for sensing of the vital signals. In addition, a surface acoustic wave filter and power detector have been used to increase the sensitivity of the system and to transform the frequency variation to voltage waveform. The experimental results show that the proposed vital sensor placed 20 mm from the body can detect the heartbeat waveform very accurately.

Original languageEnglish
Article number6099636
Pages (from-to)393-400
Number of pages8
JournalIEEE Transactions on Microwave Theory and Techniques
Volume60
Issue number2
DOIs
Publication statusPublished - 2012 Feb 1

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All Science Journal Classification (ASJC) codes

  • Radiation
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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