Blood pressure assessment with in-ear photoplethysmography

In this study, we aimed to estimate blood pressure (BP) from in-ear photoplethysmography
(PPG). This novel implementation provided an unobtrusive and steady way of recording PPG, whereas
previous PPG measurements were mostly performed at the wrist, finger, or earlobe. Methods . The time
between forward and reflected PPG waves was very short at the ear site. To minimize errors
introduced by feature extraction, a multi-Gaussian decomposition of in-ear PPG was performed. Both
hand-crafted and whole-based features were extracted and the best combination of features was
selected using a backward-search wrapper method and evaluated by the Akaike information criteria.
Hemodynamic parameters such as compliance and inertance were estimated from a four-element
Windkessel (WK4) model, which was used to pre-classify PPG signals and generate different BP
estimation algorithms. Calibration was done by using previous measurements from the same class. To
validate this n...

Source: Physiological Measurement - November 3, 2021 Category: Physiology Authors: Xiaoman Xing, Zhimin Ma, Shengkai Xu, Mingyou Zhang, Wei Zhao, Mingxuan Song and Wen-Fei Dong Source Type: research