Monte Carlo Simulated Photoplethysmography Signals for the Validation of an in Vitro Wrist Phantom

Photoplethysmography (PPG) is an optical technique used for the continuous monitoring of blood volume changes, and is integrated in a variety of medical devices and consumer wearables. Meanwhile, in silico and in vitro experiments have shown to facilitate our understanding of light-tissue interactions to assess the feasibility and accuracy of PPG-based technologies in acquiring PPG signals from the human anatomy. Therefore, this study demonstrates an approach to validate an in vitro study of a developed wrist phantom through a Monte Carlo (MC) simulation to compare PPG signals generated from experimental and computational models. The MC model simulates a PPG signal using MATLAB, and accounts for the optical and mechanical properties of the phantom and vessel in synchrony with changes in internal blood pressure. Key features of the PPG signal, such as onsets, and systolic and diastolic slopes are visually apparent. Additionally, the use of in-built MATLAB functions are recommended to improve the morphology of the PPG signal to optimise computational resources. Overall, the current study shows the applicability of Monte Carlo simulations to validate PPG data acquired from in vitro models.