Accuracy Evaluation of Robotic Tonometry Pulse Sensor System Based on Radial Artery Pulse Wave Simulator

In this article, a robotic applanation tonometry pulse sensor system has been developed to easily detect the pulse pressure index (PPI) using a pulse sensor array and reduce the position errors caused by manual operation when measuring the pulsation location of the subject's wrist using a robotic manipulator with automatic localization and pressurization. The amplitude change and shift of the pulse pressure (PP) caused by the unstable measurement angle of the tonometry device with a single sensor were measured and analyzed through an experiment with varying measurement angles. To evaluate the accuracy of the robotic tonometry system, the set PPI of the pulsatile simulator, which repeatedly generates artificial radial artery pulses, was compared with the PPI values estimated by the proposed methods. Accuracy evaluation of the pulse sensor indicates a coefficient of variability for the measured signals of up to 3.2% and a minimum accuracy of 93.7%; however, the PP calculated by a curve-fitting method applied to the measured signals from the array sensor was improved to an average of less than a 1.0% coefficient of variability and 97.9% accuracy. The developed robotic tonometry system represents a contribution to the radial pulse wave research field, which requires more accurate pulse wave analyses and PP measurements.