Abstract
This paper describes a novel application of the bidirectional audio microphones in mobile phones to measure biosignals for ubiquitous health monitoring. The bidirectional microphone has two pressure-detecting ports. A pressure-detecting film receives the differential pressure between the ports. We apply this idea to biosignal measurements for a mobile phone. We used the microphone as 1) a sphygmograph at the fingertip, 2) a stethoscope in which a delay time sensor of pulse wave arrivals from the neck near the carotid or chest near the heart to the fingertip, and 3) a bed sensing device for biosignals. When used as a sphygmograph, it detects the wave similar to the second derivative of the conventional optical pulse oxymeter output wave. When used as a stethoscope, it detects cardiac sound and the pulse wave and respiration. With two microphones, the delay time from the neck carotid to the fingertip is detected.
Original language | English |
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Article number | 6844849 |
Pages (from-to) | 545-550 |
Number of pages | 6 |
Journal | IEEE Transactions on Human-Machine Systems |
Volume | 44 |
Issue number | 4 |
DOIs | |
Publication status | Published - 2014 Aug |
Keywords
- Bidirectional microphone
- low-frequency microphone
- mobile phone
- noninvasive bed sensing
- sphygmograph
- stethoscope
ASJC Scopus subject areas
- Human Factors and Ergonomics
- Control and Systems Engineering
- Signal Processing
- Human-Computer Interaction
- Computer Science Applications
- Computer Networks and Communications
- Artificial Intelligence