Development of pneumatic bellows myoelectric hand with tactile feedback

Of the 82 thousand upper-extremity amputees in our country, the majority use prosthetic hands. Recently, research and development of myoelectric hand have come to the forefront. However, due to the usage of multiple electric actuators, the myoelectric hand is heavy, structurally complicated and expensive. Thus, the authors propose a pneumatically-driven prosthetic hand with bellows incorporated in the joint. A remarkable point of the proposed prosthetic hands is grip force, averaging 11.0 N with 5 fingers. This grip force exceeds that of general pneumatically-driven prosthetic hands. Also it is lightweight of 240 g, reducing user fatigue. The hands basic control performance showed quick response to the reference angle and pressure. In the next grasping experiment using EMG envelope, the test subject with this prosthetic hand was able to grasp a 500 ml (500 g) PET bottle. The test subject could grasp an eraser, a flexible rubber ball, and a paper cup. Moreover, this prosthetic hand is equipped with tactile feedback functions enabling users to perceive contact or reactive force from physical objects.