Development of myoelectric hand with sensory feedback system

本研究的目的是开发一种新型的肌电感觉反馈系统，并评价感觉反馈系统的实用性。感觉反馈系统信息传递方式的确定本研究开发的感觉反馈系统通过振动触觉刺激将肌电手的拍击力信息传递给使用者。调制方法采用调幅，刺激部位为上臂内侧中心部位，屈从于前臂假手的凹槽内。振动触觉刺激频率的确定。对于振动触觉刺激频率，有必要选择最敏感的频率。我们对三名健康男性的上臂进行了频率范围为1~700赫兹的振动触觉刺激。对于每个频率，我们测量了受试者能感觉到的最小刺激幅度。振动触觉刺激阈值在250~350赫兹范围内较低。然而，在该频率下，振动声发生，并使肌电手部使用者不悦。因此，我们采用10赫兹作为刺激频率，因为该频率的刺激在小于可听频率的范围内显示出最低的振动触觉刺激阈值。带感觉反馈系统的肌电手的制作为了便于日常生活携带，研制了一种微型化的肌电手电子控制电路。

The purpose of this study was to develop a new myoelectric hand with sensory feedback system and to evaluate the usefulness of the sensory feedback system.1. Decision of an information transmission method of sensory feedback systemThe sensory feedback system developed in this study transmittedan information about prasping force of myoelectrictric hand to its user with vibrotactile stimulus. The modulation method adopted an amplitude modulation and the stimulating position was the central part on the inner side of upper arm yielding to being contained inside a socket of a front arm artificial hand.2. Decision of vibrotactile stimulus frequency.It is necessary to choose themost sensitive frequency for thevibrotactile stimulus frequency. We presented vibrotactile stimulus with the range of frequency from 1 to 700 Hz to the upper arm of three health men. For each frequency, we measured the smallest amplitude of stimulation which the subjects could sense. Threshold for vibrotactile stimulus showed low at the frequency of 250-350 Hz. However with this frequency, a vibration sound occurs and displeases a myoelectric hand user. Therefore we adopted 10 Hz for the stimulation frequency because the stimulation with this frequency shows the lowest threshold for vibrotactile stimulus in the range less than audible frequency.3. Production of myoelectric hand with sensory feedback systemAn electronic control circuit for the myoelectrichand was miniaturized in order to be carried during daily life.Object grasping experimentUsefulness of the sensory feedback system was shown by the experiment, where a healthy subject was grasping soft objects with the myoelectric hand.