Real-time Dexterous Prosthesis Hand Control by Decoding Neural Information Based on EMG Decomposition

The vague interpretation of myoelectrical signals on the residual limb end makes restoring dexterous hand function in amputees still impossible. Understanding motor control between human motion intention and synaptic inputs to motor neurons also remains a significant challenge. The neural decoding methods of surface EMG signals remains challenging, which limit the application of robot hand in real life. Herein, we propose and substantiate a human-machine interface for motor control that introduces neural information of motor neurons in conjunction with the combination mechanism of muscle contraction. The interface firstly introduces a new concept of motor unit (MU) spike trains, which combines decoupling of the electrical activations on motor neuron axons with extraction of motion patterns from the discharge timings of the motor neuron pools. We realized a real-time implementation of the EMG decomposition algorithm on our developed prosthesis hand control system. The control scheme provides an accurate classification of intuitive hand motions, enabling the amputee to perform versatile finger movements of the prosthesis hand. The concept of motor neuron discharge timings was evaluated through experiments on one amputee participant and six able-bodied participants. The results show that the neuroprosthesis hand control scheme based on MU spike trains has the capacity of generating accurate and intuitive hand movements for amputees in a physical environment.