An Arterial Stiffness Measuring Wristwatch with Flexible Tactile Sensing Dense-Array

This paper reports a wristwatch to measure the arterial stiffness (AS) for the first time. A two-dimensional flexible tactile sensing dense-array is integrated in the watch. The dense-array consists of 29 × 3 ultra-small pressure sensing chips, enabling high-resolution tactile perception. Because the AS is a property about vascular elasticity and compliance, the watch senses the pressure distribution on the radial artery, and records the pressure distribution matrixes (PDM) under different external stresses. Subsequently, a deep learning model is employed to fit the regression relationship between the PDM changes and the AS degree, so that the AS degree would be assessed non-invasively and unobtrusively. Eventually, the root mean squared error (RMSE) and mean absolute error (MAE) of the predicted results reach 0.49 and 0.39, respectively, which are superior to all of the previous works.