Development of biomimetic prosthesic hand with sensory aid

本研究的目的是制造出截肢者可在日常生活中使用的肌电假肢原型。研究结果如下：电子控制电路针对用户可携带的电池驱动，我们生产了电子控制电路。控制电路由电机控制电路、肌电图处理电路和电机驱动电路组成。为了节省电子控制电路的电力，我们更换了一个中央处理单元。通过对中央处理器的改进，我们开发了一种新的控制程序。由于完成了整个控制电路的设计，我们进行了第一次小型化电路板的试验设计，并考察了小型化的可能性。我们开发了一种力检测电路的自动偏置调节电路。通过实验确定了调制方式、电刺激位置和刺激点个数。因此，我们设计了一种不会对受试者造成伤害的方法。我们证实了这三个阶段的信息可以通过四个电极传输。在感官辅助方面，我们研究了两种电刺激方法。一种是将两种不同相位的电流送入人体，产生的电流刺激人体的方法。通过这种方法，我们可以在低电压下刺激身体。我们证实了通过改变两个刺激电流的相位，我们可以用固定电极改变刺激的位置，并且在施加刺激时可以测量到肌电信号。另一种方法是连续给予身体两种刺激。利用该方法，我们可以以95%左右的准确率传输假手的状态。

The purpose of this study is to produce the prototype myoelectrical hand prosthesis which amputee can use in everyday life. The results of the study are shown as follows.Electronic control circuitWe produced electronic control circuit aiming at the battery drive that the user could carry. The control circuit consists of a motor control circuit, electromyogram processing circuit, and a motor drive circuit. We changed a central processing unit for power-saving of electronic control circuit. With modification of a central processing unit, we developed a new control program. Because a design of the whole control circuit was finished, we made the first trial circuit board design for miniaturization and examined possibility of miniaturization. We developed the automatic offset regulation circuit of the force detecting circuit in hand.Sensory aid unitThe experiments were carried out to decide the modulation method, the position of electrical stimulation, and the number of stimulus point. As the result, we devised the method that did not inflict on subjects. And we confirmed that the three phases of information could be transmitted with four electrodes.For the sensory aid, we examined two kinds of electric stimulation method. One is the method that two different current of phase fed to the body and that the created beat current stimulated the body. By using this method, we could stimulate body in low voltage. And we confirmed that we could change the stimulus position with the fixed electrode by changing phase of two stimulus current and that the myoelectrical signal could be measured when this stimulation was applied. Another method is to give two kinds of stimulus to the body in succession. With this method, we could transmit the state of the hand prosthesis in accuracy of around 95%.