Wireless and Soft Pulse Wave Measurement Device with Printed Ferroelectric E-tattoo Sensor

Abstract

We propose a non-invasive pulse wave monitoring system that integrates a fully printed, partially stretchable ferroelectric electronic tattoo (e-tattoo) sensor with a soft, elastomer-encapsulated, partially stretchable data transmission unit (DTU). The DTU includes a rechargeable battery, Bluetooth-enabled wireless data transmission, and optimized signal conditioning circuitry for the e-tattoo sensor. We demonstrate: 1) a simple, printing-based fabrication process for the e-tattoo sensor and its integration with the DTU; 2) significant improvement in pulse wave index accuracy through optimized electrode material selection used in the e-tattoo sensor (e.g., reduction in relative error of relative crest time index from 56.3% to 0.2%); 3) enhanced sensitivity via integration of the e-tattoo on the DTU's soft encapsulation (increased from 25 pC/N to 1277 pC/N); and 4) successful extraction of clinically relevant pulse indices from radial artery of a human study subject.