Development of Finger Rehabilitation Device using Pneumatic Actuator made of Nylon Film

Abstract

This paper presents our study on a development of a finger rehabilitation device, especially a prototype of pneumatic actuator we newly designed for a finger rehabilitation. Because the actuator made from nylon film can be actuated under low air pressure, a a-little-volume pump can even actuate the nylon-film actuator. The finger rehabilitation device including the nylon-film actuator and the air pump driven by a DC motor will be suitable for the rehabilitation at home for people who want to carry it anywhere and anytime because the actuator and the air pump are small and light. The nylon-film actuator is designed for two kinds of finger motions. One is for the extension that is most important to people with hand paralysis. Another is for the flexion, which each joint angle and the actuator's lengths between joints can be adjusted for individuals. The actuator is activated under low air pressure and assists finger motions even if a little volume air pump driven by a low power DC motor is used for a drive unit. Before we made a prototype of the nylon-film actuator, we considered using one of the existing soft pneumatic actuators made from elastomer for the rehabilitation device. However, it was not activated at under low air pressure drive unit. In contrast to the weight of the previous elastomer actuator that is approximately 30g, the nylon-film one we developed is approximately 10g. So, the device consisted of the actuators will give less stress for people's bodies and allow them to continue finger rehabilitation for extended periods of time. The rehabilitation device consisted of the nylon-film actuator with small drive unit will be also portable and wearable. Moreover, because the nylon film is cheap and the actuator can be easily made, it is more accessible than the elastomer actuator.