Probabilistic models for prosthetic control based on EMG decomposition

Modern prosthetic control can be significantly enhanced due to the use of EMG decomposition. This technique permits to extract the activity of motor neurons that control the movement, thus giving a direct representation of neural command. This activity, being unaltered by factors non-related to motion, such as type and position of EMG electrode, is of great interest in prosthetic control. Existing real-time decomposition methods, however, provide activities of a very limited number of motor neurons (up to ten). This can be considered insufficient for intent inference. In this work, we present a probabilistic approach to intent inference that uses existing models of relations between the behavior of motor neurons and the movement. We compare our approach with a conventional one presented in the literature and show that it produces significantly better results when provided with a small number of decomposed motor neurons. To assess its performance in a fully controlled environment, we have developed a physiology-based simulation model of EMG and muscle contraction. Moreover, the analysis was also performed using experimental recordings of muscle contractions.