Pneumatic artificial muscle-based stroke rehabilitation device for upper and lower limbs

Rehabilitation of the upper and lower limbs is crucial for patients recovering from strokes, surgeries, or injuries. Traditional rehabilitation often takes place in hospitals under the guidance of a therapist, which can delay treatment due to various constraints. This paper proposes a soft robotic device designed to aid in the flexion and extension of both the elbow and knee. The device utilizes pneumatic artificial muscles, constructed from an elastomeric bladder with a threaded mesh exterior, as its actuating mechanism. It operates in two distinct modes: a continuous passive mode, where continuous, repetitive flexion, and extension of limbs are carried out, and an active intent-based assisted mode, which detects a patient's movement intention via surface electromyography (sEMG) and subsequently aids in the movement execution. To test the effectiveness of the device, sEMG electrodes were placed on upper and lower limbs of six healthy male subjects, range of motion, and muscle activity were recorded with and without the device. Also NASA task load index (NASA-TLX) was calculated for the usability of the device. The results indicate the required muscle activity and range of motions for both upper and lower limb rehabilitation are effectively generated in both the modes.