Development of the myoelectric prosthetic hand with sensory feedback system using electrotactile stimulation

本研究的目的是开发高可靠性、便携式的肌电假手及其电触觉刺激感觉反馈系统。(1)假手控制电路在原有电路的基础上，研制出便携式低功耗的假手电路。(2)感觉反馈系统新型人工触觉系统作为肌电假手感觉反馈系统。这个系统被传递了几个词(口头信息)，其中两个通道的电触觉刺激能够产生明显的运动到前臂。提供了关于握持物体的状态和手指角度的语言信息。为了展示该系统的有效性，我们对一名健康受试者进行了抓取实验。(3)人工指尖为了研制肌电假手用的柔软人工指尖，对指尖的静态力学性能进行了研究。以力学性能为指标，研究了皮肤和组织的应力应变关系。受试者是四名正常男性和一名正常女性。结果表明，随着应变的增加，应力呈非线性增加。根据所获得的性能，用两种氨基甲酸酯树脂制成了人造指尖。结果表明，戴上人工指尖的手可以稳定地抓取玻璃。

The purpose of this research was to development of the high reliability and portable myoelectric prosthetic hand and its sensory feedback system using electrotactile stimulation.(1) Control circuits for prosthetic handThe portable and low powered electric circuit for prosthetic hand was developed based on the previous version of the circuits.(2) Sensory feedback systemThe novel artificial tactile system was developed as sensory feedback system for the myoelectric prosthetic hand. This system was transmitted a few words (verbal information) in which two channel electrotactile stimulation capable of generating apparent movements was applied to the forearm. The verbal information was provided regarding the state of grasping objects and the finger angle. In order to show the usefulness of this system, we executed grasping experiments with one healthy subject. It was shown that the subject could grasp the object for shorter periods with this system than without system.(3) Artificial fingertipsThe static mechanical properties of the fingertips were investigated in order to develop the soft artificial fingertips for the myoelectric prosthetic hand. The relationships between the strain and stress of the skin and tissue were investigated as the mechanical properties. The subjects were four normal men and one normal woman. It was shown that the stress was increased non-linearly with increasing of the strain. The artificial fingertips based on the obtained properties were made from two kinds of urethane resin. It was shown that the glass could be grasped stably with the hand attached the artificial fingertips.