Functional test of a training device for moving fingers and wrist joints using soft pneumatic actuator

Abstract:
In this study, we developed a finger and wrist motion support device for preventing joint contracture using a slide table that can adjust to the size of the user's hand and a pneumatic soft actuator whose length can vary. By directly applying the pneumatic soft actuator to the hand, flexion and extension movements are performed at each joint to prevent contracture. To investigate the performance characteristics of the actuators used in the prototype device, experiments measuring force generation were conducted. The experiments revealed that the box-type actuator ceased to increase its generated force when it approached a certain distance, while the laminated-type actuator, which inflated in a fan-shaped manner, increased linearly. This result is attributed to the fact that the box-type actuator allows force to escape from surfaces other than the contact surface and the fixed surface. Additionally, the operation of the device was verified with one male participant in his twenties. The flexion motion achieved a success rate of around 90% of the target value, but the wrist extension motion resulted significantly lower compared to other movements.