Arteriosclerosis Assessment based on Single-Point Fingertip Pulse Monitoring Using a Wearable Iontronic Sensor.

Arteriosclerosis, which appears as a hardened and narrowed artery with plaque buildup, is the primary cause of various cardiovascular diseases such as the stroke. Arteriosclerosis is often evaluated by clinically measuring the pulse wave velocity (PWV) using a two-point approach that requires bulky medical equipment and a skilled operator. Although wearable photoplethysmographic sensors for PWV monitoring have been developed in recent years, likewise, this technique is often based on two-point measurement, and the signal can easily be interfered by the natural light. Here, we report a single-point strategy based on stable fingertip pulse monitoring using a flexible iontronic pressure sensor for heart-fingertip PWV (hfPWV) measurement. The iontronic sensor exhibits high pressure resolution on the order of 0.1 Pa over a wide linearity range, allowing the capture of characteristic peaks of fingertip pulse waves. We extract the forward and reflected waves of the pulse and compute the time difference between the two waves for hfPWV measurement using the Hiroshi's method. We further establish a hfPWV-based model for arteriosclerosis evaluation with an accuracy comparable to existing clinical criteria, and have verified the validity of the model clinically. The work provides a reliable technique that can be used in wearable arteriosclerosis assessment systems. This article is protected by copyright. All rights reserved.