A Novel Photo-electro-mechano Sensing Array for the Visualization and Estimation of Tonoarteriogram

Existing cuffless blood pressure (BP) monitoring technologies commonly rely on single-site measurements with unimodal sensor configurations, thereby constraining the precision and visualization of the two-dimensional data. Building upon our previous observations regarding the significant influence of measurement sites on BP evaluation, and leveraging the widely acknowledged utility of electrocardiography (ECG) in BP assessment, in this study, we develop a multimodal photo-electro-mechano tonoarteriographic (TAG) imaging system, enabling continuous visualization of local BP variation and estimation of central BP. The system integrates a 3×3 photoplethysmography (PPG) sensor array, one-lead ECG, and a 2×2 pressure sensor array, allowing to collect simultaneously 15 channel physiological signals. The proposed system was tested with 20 subjects and the experimental results reveal noticeable variations in local pulse transit time (PTT)/BP across different anatomical structures at the measurement site. To further improve the system performance, we designed and tested a flexible 2×4 ultrasound sensor array and demonstrated its feasibility to augment the system's capability for central BP estimation. In summary, the proposed system can not only estimate continuously central BP but also visualize the two-dimensional local BP/PTT variation at the measurement site, holding potential to support clinical decision-making and offering geographic-dependent information for micro-circulation investigations. © 2024 IEEE.