Application of Flexible Micro-Actuator to Medical Precision-Work

将机械臂应用于医疗手术中，执行机构必须具有对机体的适应性和不受感染的处理能力。与全身麻醉一样，吸入法是通过肺部吸收和排泄的气体控制，使患者停止意识、疼痛和活动。这项工作的问题是如何在不损伤粘膜的情况下将气管插入支气管。通常操作者设法通过会厌和声门将硬内窥镜插入肺部，接受来自软膜的反作用力。内窥镜有时难以应用于肥胖的成人和儿童。本研究从医院的仪器、气体、管道和操作工作入手，提出了一种新型的柔性执行器——FMA的构想，该执行器具有空心传感机构。首先，制作了一个直径5mm，长度50mm的小尺寸FMA，具有三个3自由度的内腔。在FMA中间还有两根直径0.2毫米的光纤，用于感知支气管的中空。其工作原理是通过气动压力控制FMA的姿态角，气动压力由光学传感开/关信号所需的3端口开关阀组合控制。FMA在0.4MPa压力下在0.4s内弯曲90度。采用新设计的二维气管咽声门塑料模型，从手术时间上评价其性能。与传统手写笔操作相比，工作时间由110秒缩短至34秒。

Applying a robotic manipulator to a medical operation, it is important for an actuator to have adaptability to organism and to be disposal for being free from infection. As general anesthesia, inhalation method is appropriate for a patient to stop the consciousness, pain and mobility by the gas-control of absorption and excretion through lung. The issue for this work is how to insert the gas-pipe into the bronchus without injuring the mucous membrane. Usually the operator manages to insert the hard endoscope to the lung through the epiglottis and glottis receiving the feeling of reaction force from the soft membrane. The endoscope is sometimes difficult to be applied to fat adults and children. The research started to study the instrument, gas, tubes and operation-work in the hospital, which presents an idea to make a new flexible actuator, called FMA,with hollow-sensing mechanism.Firstly a small size FMA of 5mm in diameter and 50mm in length with three internal chambers for 3 degrees of freedom is made. It has also two optical fibers of 0.2mm in diameter in the middle of FMA for sensing the hollow of the bronchus. The working principle is to control the attitude angle of the FMA by pneumatic pressure which is controlled by a combination of 3-port switching-valve demanded by the optical sensing on/off signal. The FMA bends 90 degrees at 0.4MPa pressure within 0.4s. The performance is evaluated from the operating time by using a newly designed plastic-model of two-dimensional trachea and pharynx with glottis. The working time is shorten from 110s to 34s compared to conventional operation by stylus.