Advancing Wearable Cardiovascular Monitoring: Integration of Flexible Piezoresistive Sensors for Robust Pulse Waveform Detection

Abstract

Wearable, flexible piezoresistive pressure sensors have diverse applications, spanning electronic skin, robotic limbs, and cardiovascular monitoring. Recent advancements in wearable health monitoring devices utilizing these sensors show promise for continuous cardiovascular monitoring. However, a substantial gap exists between laboratory development and market availability for pressure sensor based pulse monitoring. Challenges include the lack of effective testing schemes ensuring robust wearable operation and the necessity of bulky signal acquisition equipment, limiting adaptability. This study addresses these challenges by integrating the outputs of multiple flexible, skin-mountable piezoresistive sensors to create a robust wearable platform. This platform encompasses both sensing and miniaturized signal acquisition for arterial pulse waveform monitoring. The single piezoresistive sensor in our design exhibits sensitivity (1.4 kPa-1 at 2 – 8 kPa). This robust signal allows for the use of simple, compact signal collection devices mounted on a wristband. Moreover, the capability of the the system allows for detection of the three distinct peaks associated with the full pulse waveform, including the systolic, diastolic, and reflected diastolic peaks. In validation, a comparison between the wrist pulse waveform obtained with the compact signal collection device and a standard sourcemeter (Keithley 2460) confirms the capability of our wearable system to resolve the three distinct peaks. This work contributes to bridging the gap between research and practical applications, offering a potential solution for widespread adoption of continuous cardiovascular monitoring technology in diverse settings.