Comparison of specifications and measurement signals of two type sensors that measure heartbeat information at the fingertip

• Published in: Measurement. Sensors 2021-12, Vol.18, p.100095, Article 100095
• Main Authors: Koyama, Shouhei, Haseda, Yuki, Kitagawa, Shota, Okazawa, Futa, Satou, Yuuki
• Format: Article
• Language: English
• Subjects: Fiber bragg grating sensor; Fingertip; Photoplethysmography sensor; Signal waveform; Systolic and diastolic peak
• ISSN: 2665-9174; 2665-9174
• DOI: 10.1016/j.measen.2021.100095

We compared and verified the signal waveforms and specifications measured by two sensors that can detect heartbeat information from the fingertips. A Photoplethysmography (PPG) sensor, which is a photo-electric volume pulse wave sensor, and an Fiber Bragg grating (FBG) sensor, which is an optical fiber type strain sensor, were used. These sensors were placed on the index and middle fingers of the subject and measured at the same time. The FBG sensor detected arterial strain in the fingertips, and the PPG sensor detected hemoglobin in the capillaries of the fingertips. The signal waveforms measured by these sensors were very similar. However, the FBG sensor detected a signal waveform in which the systole and diastole of the heart were separated. The PPG sensor and FBG sensor have different characteristics in terms of hardware and specifications, and more detailed heartbeat information can be detected by combined using or separately using them.