Development of Medical System for Diagnosis and Treatment with Internal Robots

研究小组开发了一种不与组织接触就能在人体内驱动医疗设备的新技术。该方法利用电磁微电机驱动螺旋带肋圆柱时，由于黏液的流体动力作用产生推力。根据数值分析和试验结果，对叶轮和肋部进行了优化设计。(2)研究了在乙烯管中运动的装置的推力与阻力的关系。阐明了曲率和分支对推力的影响。(3)我们尝试在犬消化管中驱动一个连接镍钛合金丝的叶轮。经口前推可达十二指肠，经肛门后推可达升结肠，不损伤组织壁。(4)制作了微型机器人，在透明管内测量了机器人的运动速度和推力，研究了曲率、分支和内半径变化对机器人推进力的影响。(5)当天然黏液不足时，可通过提供黏液来保证黏液的稳定发展。(6)发现振动降低了粘性流体膜的摩擦。通过这种方法，降低了医疗器械的电阻。此外，如果在振动中加入振荡，则可以实现主动驱动。(7)利用体外电磁铁磁场控制导尿管导航的新技术。通过控制磁体内的电流和磁体的排列，将器件引导到绕组或分支区。

(1)The research team developed a new technology to drive medical devices in a human body without contacting with tissues. By this method, thrust force arises due to hydrodynamic effect of mucus when a spiral ribbed cylinder is driven by an electromagnetic micro-motor. The optimal design for the impeller and ribs was found according to results of numerical analysis and experiment.(2)The relation between thrust force and resistance was investigated for the device that moves in vinyl tube. Effects of curvature and branch on thrust were clarified.(3)We tried to drive an impeller attached to wire of Ni-Ti alloy in canine digestive tube. The device reached the duodenum in the case of frontward driving through mouth and it reached the ascending colon in the case of backward driving through anus, easily without any injury of the tissue wall.(4)We fabricated a micro-robot and measured moving velocity and thrust in transparent tube, and investigated the effect of curvature, branch and change of internal radius on propulsion.(5)When natural mucus is insufficient, steady advance was assured by supplying glutinous starch, origo or nectar as artificial mucus.(6)We found that friction in viscous fluid film is reduced by vibration. By this method, resistance of a medical device was reduced. Further, active driving was possible if oscillation was added to vibration.(7)A new technology to navigate catheters by control of magnetic field of electromagnets locate outside of the body. The device was guided at winding or branching region by control of electric current in the magnets and their arrangement.