Wrist location by wearable bracelet belt resonators

This paper presents the preliminary evaluation of a wearable 1-dimensional frequency multiplexed sensor array using microstrip-line-excited complementary split-ring resonators (CSRRs) module for detecting the location of the wrist. The sensor array was fabricated on a cylindrical structure, and a scheme was devised by which to measure relative changes in the location of the wrist within a wearable devise. Unlike previous devices that record changes in the resonant frequency as well as the depth of the transmission notch, the proposed method requires only the magnitude of the transmission coefficient (dB) at a specified frequency, thereby avoiding the need to track shifts in the resonance frequency. Experiment results demonstrate the performance of the sensor in detecting relative changes in distance (1.16 dB/mm) from 0 - 20mm.