Estimated Results of R-R Interval Using a Small Card-Sized VHF-Band Contactless Heartbeat Sensor Module

The constant monitoring of biological data such as heart rate, heartbeat interval, and respiration rate enables the estimation of physical and psychological conditions. In our previous study, we adopted radio-wave sensors as non-contact and non-invasive sensors and developed a non-contact heart rate sensor that uses a small loop antenna in the very-high-frequency band with low radiation efficiency. In this study, we extracted peaks from heart rate waveforms obtained from 9 participants with a small card-sized (60 mm × 90 mm) heartbeat sensor module and demonstrated that the heartbeats interval can be obtained with high accuracy with an average acquisition error of R-R interval of 123 ms.