Development of an EMG-controlled Hand Rehabilitation Exoskeleton with Series Elastic Actuators

With the improvement of living standards, the increased incidence of cardiovascular disease has led to an increased likelihood of stroke in elderly people, resulting in defects of hand function. In this paper, an underactuated hand rehabilitation exoskeleton is proposed to help them regain hand function. The exoskeleton uses a series elastic actuator (SEA) to achieve bidirectional flexible drive of the joint and uses electromyographic (EMG) signal control based on muscle force estimation. Structurally, to be able to rehabilitate three joints simultaneously and reduce the heavy weight of multiple motors, a single SEA with a linear motor was used for each finger. The three joints of the hand move through a multi-link coupling mechanism. At the same time, the SEA realizes force feedback without force sensors. Exoskeletons can also reduce discomfort caused by misaligned joints. In terms of control, EMG signals are used to achieve muscle force estimation, aiming to control exoskeleton movement. Then we conducted the SEA stiffness calibration experiment, muscle force estimation experiment and adjustment tests of different admittance parameters experiment.