An inchworm-like capsule robot(ILCR) is a promising device for a minimally invasive diagnosis and treatment of colon diseases. It consists of two expanders and one extensor, the former provides a traction force by exp...An inchworm-like capsule robot(ILCR) is a promising device for a minimally invasive diagnosis and treatment of colon diseases. It consists of two expanders and one extensor, the former provides a traction force by expanding the colon and the latter can elongate and retract to enable active locomotion. However, the locomotion efficiency of the ILCR can be seriously lowered by the complex colon environment featuring slippery, viscoelastic, and suspend properties, which has been a main obstacle to its clinical application. This paper aims at improving the locomotion efficiency of the ILCR by optimizing its extensor design. To do this, the locomotion resistance of the ILCR in the colon is analyzed, and complying with a requirement that the traction force must be larger than the locomotion resistance to avoid slipping, a restriction on the extensor design is obtained. Then under the restriction and with reference to the Hyperelastic model which correlates stress and strain of colon tissue, a model for analyzing the influence of the design parameters of the extensor on the locomotion efficiency of the ILCR is built. With this model, the extensor has been optimized and the optimized results have been used to guide the development of a novel extensor, which employs two pairs of lead-screws and nuts and is actuated by one motor. Ex-vivo experiment has shown that the novel extensor can improve the locomotion efficiency of an ILCR prototype by 57%, without changing its total length.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.61803347,61673271&81601631)the Shanxi Province Science Foundation for Youths(Grant No.201801D221201)+3 种基金the Youth Academic Leader Support Project of North University of China(Grant No.QX201808)the Opening Foundation of Shanxi Key Laboratory of Advanced Manufacturing Technology(Grant No.XJZZ201803)the Science and Technology Commission of Shanghai Municipality(Grant No.15441903100)the Science and Technology on Electronic Test and Measurement Laboratory,North University of China(Grant No.WD614200104011804)
文摘An inchworm-like capsule robot(ILCR) is a promising device for a minimally invasive diagnosis and treatment of colon diseases. It consists of two expanders and one extensor, the former provides a traction force by expanding the colon and the latter can elongate and retract to enable active locomotion. However, the locomotion efficiency of the ILCR can be seriously lowered by the complex colon environment featuring slippery, viscoelastic, and suspend properties, which has been a main obstacle to its clinical application. This paper aims at improving the locomotion efficiency of the ILCR by optimizing its extensor design. To do this, the locomotion resistance of the ILCR in the colon is analyzed, and complying with a requirement that the traction force must be larger than the locomotion resistance to avoid slipping, a restriction on the extensor design is obtained. Then under the restriction and with reference to the Hyperelastic model which correlates stress and strain of colon tissue, a model for analyzing the influence of the design parameters of the extensor on the locomotion efficiency of the ILCR is built. With this model, the extensor has been optimized and the optimized results have been used to guide the development of a novel extensor, which employs two pairs of lead-screws and nuts and is actuated by one motor. Ex-vivo experiment has shown that the novel extensor can improve the locomotion efficiency of an ILCR prototype by 57%, without changing its total length.