Measuring Vital Signs on Fingertip Using K-Band Spherical Dielectric Resonator

This paper presents a resonator-based sensor for vital sign detection using a spherical dielectric resonator (SDR) operating at a frequency of approximately 26 GHz. The SDR at K-band can function as a highly-sensitive sensor due to reduced conduction loss, low radiation leakage, compact size, and enhanced signal-to-interference-plus-noise ratio (SINR) compared with traditional planar metallic resonators. Based on the proposed SDR sensor, the fingertip pulse signs can be detected merely by the sole sensoring resonator without external circuits. The SINR of the heartbeat signal detected at the fingertip is improved by more than 4.2 dB, compared to a metallic resonator-based sensor.