上海交通大学精密仪器系康复工程研究室专门为上臂截肢者(即肘关节以上,肩关节以下截肢者)研制JM-I型和JM-II型三自由度电动上臂假手。于1987年10月通过鉴定。这两种型号的假手都具有三个自由度,能完成六个基本动作,即假手手指的开闭、前臂或腕部的旋转,肘关节的伸屈等。JM-I型是用二个开关逻辑来控制六个动作,每一个开关闭合一次手指开闭、闭合二次前臂旋转、闭合三次肘部伸屈。两个开关的动作方向相反。JM-II型的控制采用以人为主体的 Shanghai Jiao Tong University Department of Precision Instrument Rehabilitation Engineering Laboratory specifically for the upper arm amputees (ie above the elbow, shoulder amputation below the amputees) developed JM-I and JM-II type three-degree-of-freedom electric arm artificial hand. In 1987 October passed the appraisal. Both types of prosthetic hand have three degrees of freedom, to complete the six basic movements, namely the opening and closing of false fingers, forearm or wrist rotation, elbow flexion and so on. JM-I type uses two switching logic to control six movements, each opening and closing a finger to open and close, close the second forearm rotation, closing elbow flexion three times. The two switches move in the opposite direction. JM-II type of control using people as the main body