Unobtrusive, Cuffless Blood Pressure Monitoring Using a Soft Polymer Sensor Array With Flexible Hybrid Electronics

The state-of-the-art systems for blood pressure (BP) monitoring often use cuffed-based rigid sensory systems, bulky electronics, multiple measurement sites, and intermittent measurement. Here, we introduce a new type of epidermal electronics that were specifically designed for cuffless BP-monitoring system, named multiPANI. The proposed fully integrated wearable device is equipped with a wireless-flexible hybrid electronics, a personalized flexible sensor array, and encapsulated with a thin biocompatible elastomer layer for soft-conformal contact with the complex skin surface structure. In addition, a unique capability of multiPANI to monitor multiple local pulse wave velocity (PWV) enabling us to develop a novel hybrid BP estimation algorithm that combine a selective-local PWV and high-signal-to-noise-ratio-based pulse wave analysis (PWA) for robust-cuffless BP-monitoring system. Experimental results indicate that the proposed hybrid selective PWV-PWA BP model outperform the typical single-PWV BP model by ~30%, with an acceptable root-mean-square-error performance of 3.94 ± 0.5 and 1.88 ± 0.9 mmHg, for systolic BP and diastolic BP respectively. Collectively, this study demonstrated a unique solution of fully integrated epidermal electronics and hybrid BP estimation algorithm for a robust, cuffless, and long-term BP monitoring.