AI-Controlled Closed-Loop Electrical Stimulation Implants: A Feasibility Study

Abstract

Miniaturized electrical stimulation (ES) implants show great promise in practice, but their real-time control by means of biophysical mechanistic algorithms is not feasible due to computational complexity. Here, we hypothesize machine learning methods can approximate these models while being much more computationally efficient. To prove this hypothesis, we estimate the normalized twitch force of the stimulated extensor digitorum longus muscle on n=11 Wistar rats with intra- and cross-subject calibration. After 2000 training stimulations, we reach a mean absolute error of 3% in an intra-subject setting and 20% in a cross-subject setting with a random forest regressor. To the best of our knowledge, this work is the first experiment showing the feasibility of AI to simulate complex ES mechanistic models. However, the results of cross-subject training motivate more research on error reduction methods for this setting.