Near-Infrared Light Sensing System for Non-Contact and Long-Distance Pulse Measurement

Abstract

This paper reports near-infrared light (NIR) sensing system for non-contact pulse measurement. Measurement of the physiological conditions such as heart beat rate (HBR) and heart rate variety (HRV) in daily life becomes important subjects in aging society. Pulse wave is considered to be important parameter to estimate the health condition. However, conventional pulse sensors constrain the body of the measured person during measurement, and is not suitable for the life logging. Although pulse measurement using CCD achieved non-contact measurement, this method is easily affected by fluctuation of ambient light intensity. We fabricated non-contact pulse measurement system using nearinfrared light for stable measurement of HBR and HRV. This sensor corrects the scattering light to improve S/N ratio. We also investigate the suitable area of pulse measurement in face by our developed unconstraint pulse sensor. Finally, we demonstrated pulse measurement and compare the HBR and LF/HF calculated by HRV with unconstraint pulse sensor.