A prototype of a pneumatic device for rehabilitation of the hand was designed, built and tested. Progressive impairment of hand function may result from a prolonged condition of hemiparesis, such as resulting from stroke. Reduced daily use of the affected limb, spasticity and contracture contribute to progressive impairment. Physical therapy attenuates the impairment in many patients, but regular sessions of physical therapy are difficult to maintain due to the associated costs, limited insurance coverage, and necessity of being at the clinic for each session. Systems or devices suitable for home-based therapy sessions would widen the accessibility of physical therapy to more patients. However, reported therapeutic systems appear to be expensive, heavy and complicated, thus limiting their suitability for widespread application in home settings. Recent reports of pneumatic based hand therapy systems suggest a platform for hand rehabilitation that would be simpler, lighter, less expensive, and have a lower risk of safety concerns. The design utilized in this project has the affected hand encased in a glove apparatus that has an embedded air bladder positioned ventral to each of the five digits on the palmer side of the hand, such that the bladder acts to assist extension of each finger and thumb as internal air pressure increases. Several alternative designs of glove-bladder combinations were designed, fabricated and tested. An electro-pneumatic regulator (SMC Corp. of America, Noblesville, IN) controlled the pressure of air to the bladders from an air compressor. The pneumatic regulator was controlled by a custom designed and assembled microcontroller (Arduino, open source) based control system. The microcontroller controlled solenoids that functioned as valves for the passage of air to the bladders from the pneumatic regulator, one solenoid for each of the 5 bladders in a glove. Tests were done to compare alternative glove-bladder designs. For a bladder corresponding to one digit, the relations between air pressure and the resulting torque were explored using a system of weights. Moreover, for constant pressure levels, the relations between angle of a digit and torque were explored. The pneumatic hand rehabilitation system developed in this project shows promise toward development of pneumatic hand therapy systems that would be suitable for home-based therapy.
The effectiveness of home-based therapy on functional outcome, self-efficacy and anxiety among discharged stroke survivors