Science China Technological Sciences

, Volume 62, Issue 11, pp 1930–1938 | Cite as

Optimization design of extensor for improving locomotion efficiency of inchworm-like capsule robot

  • JinYang GaoEmail author
  • GuoZheng Yan
  • YunBo Shi
  • HuiLiang Cao
  • Kun Huang
  • Jun Liu


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.


inchworm-like capsule robot extensor design locomotion resistance locomotion efficiency 


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  1. 1.
    Iddan G, Meron G, Glukhovsky A, et al. Wireless capsule endoscopy. Nature, 2000, 405: 417CrossRefGoogle Scholar
  2. 2.
    Ciuti G, Caliò R, Camboni D, et al. Frontiers of robotic endoscopie capsules: A review. J Micro-Bio Robot, 2016, 11: 1–18CrossRefGoogle Scholar
  3. 3.
    Neumann H, Fry L C, Nägel A, et al. Wireless capsule endoscopy of the small intestine. Curr Opin Gastroenterol, 2014, 30: 463–471CrossRefGoogle Scholar
  4. 4.
    Gao M Y, Hu C Z, Chen Z Z, et al. Design and fabrication of a magnetic propulsion system for self-propelled capsule endoscope. IEEE Trans Biomed Eng, 2010, 57: 2891–2902CrossRefGoogle Scholar
  5. 5.
    Yim S, Sitti M. Design and rolling locomotion of a magnetically actuated soft capsule endoscope. IEEE Trans Robot, 2012, 28: 183–194CrossRefGoogle Scholar
  6. 6.
    Rey J F, Ogata H, Hosoe N, et al. Blinded nonrandomized comparative study of gastric examination with a magnetically guided capsule endoscope and standard videoendoscope. Gastrointest Endosc, 2012, 75: 373–381CrossRefGoogle Scholar
  7. 7.
    Mahoney A W, Abbott J J. Five-degree-of-freedom manipulation of an untethered magnetic device in fluid using a single permanent magnet with application in stomach capsule endoscopy. Int J Robot Res, 2016, 35: 129–147CrossRefGoogle Scholar
  8. 8.
    Zhu S, Wang J, Qian Y, et al. The application value of magnetic-controlled capsule endoscopy for gastric diseases in physical examination of asymptomatic population. Chin J Dig Endosc, 2017, 34: 309–313Google Scholar
  9. 9.
    Zhou H, Alici G, Than T D, et al. Modeling and experimental investigation of rotational resistance of a spiral-type robotic capsule inside a real intestine. IEEE/ASME Trans Mechatron, 2013, 18: 1555–1562CrossRefGoogle Scholar
  10. 10.
    Zhang Y S, Wang N, Du C Y, et al. Control theorem of a universal uniform-rotating magnetic vector for capsule robot in curved environment. Sci China Tech Sci, 2013, 56: 359–368CrossRefGoogle Scholar
  11. 11.
    Ye B, Zhang W, Sun Z, et al. Study on a magnetic spiral-type wireless capsule endoscope controlled by rotational external permanent magnet. J Magn Magn Mater, 2015, 395: 316–323CrossRefGoogle Scholar
  12. 12.
    Zhang Y, Chi M, Su Z. Critical coupling magnetic moment ofa petal-shaped capsule robot. IEEE Trans Magn, 2016, 52: 1–9Google Scholar
  13. 13.
    Valdastri P, Webster R J, Quaglia C, et al. A new mechanism for mesoscale legged locomotion in compliant tubular environments. IEEE Trans Robot, 2009, 25: 1047–1057CrossRefGoogle Scholar
  14. 14.
    Kim H M, Yang S, Kim J, et al. Active locomotion of a paddling-based capsule endoscope in an in vitro and in vivo experiment (with videos). Gastrointest Endosc, 2010, 72: 381–387CrossRefGoogle Scholar
  15. 15.
    Kim Y T, Kim D E. Novel propelling mechanisms based on frictional interaction for endoscope robot. Tribol Trans, 2010, 53: 203–211CrossRefGoogle Scholar
  16. 16.
    Sliker L J, Kern M D, Rentschler M E. An automated traction measurement platform and empirical model for evaluation of rolling micropatterned wheels. IEEE/ASME Trans Mechatron, 2015, 20: 1854–1862CrossRefGoogle Scholar
  17. 17.
    Phee L, Accoto D, Menciassi A, et al. Analysis and development of locomotion devices for the gastrointestinal tract. IEEE Trans Biomed Eng, 2002, 49: 613–616CrossRefGoogle Scholar
  18. 18.
    Chen W, Yan G, He S, et al. Wireless powered capsule endoscopy for colon diagnosis and treatment. Physiol Meas, 2013, 34: 1545–1561CrossRefGoogle Scholar
  19. 19.
    Gao J, Yan G, Wang Z, et al. Design and testing of a motor-based capsule robot powered by wireless power transmission. IEEE/ASME Trans Mechatron, 2016, 21: 683–693CrossRefGoogle Scholar
  20. 20.
    Dario P, Ciarletta P, Menciassi A, et al. Modeling and experimental validation of the locomotion of endoscopic robots in the colon. Int J Robot Res, 2004, 23: 549–556CrossRefGoogle Scholar
  21. 21.
    Kwon J, Park S, Park J, et al. Evaluation of the critical stroke of an earthworm-like robot for capsule endoscopes. Proc Inst Mech Eng H, 2007, 221: 397–405CrossRefGoogle Scholar
  22. 22.
    Zarrouk D, Sharf I, Shoham M. Analysis of wormlike robotic locomotion on compliant surfaces. IEEE Trans Biomed Eng, 2011, 58: 301–309CrossRefGoogle Scholar
  23. 23.
    Zarrouk D, Sharf I, Shoham M. Conditions for worm-robot locomotion in a flexible environment: Theory and experiments. IEEE Trans Biomed Eng, 2012, 59: 1057–1067CrossRefGoogle Scholar
  24. 24.
    Gao J, Yan G. Locomotion analysis ofan inchworm-like capsule robot in the intestinal tract. IEEE Trans Biomed Eng, 2016, 63: 300–310CrossRefGoogle Scholar
  25. 25.
    Chen W, Yan G, Wang Z, et al. A wireless capsule robot with spiral legs for human intestine. Int J Med Robot Comput Assist Surg, 2014, 10: 147–161CrossRefGoogle Scholar
  26. 26.
    Zhang C, Liu H, Tan R, et al. Modeling of velocity-dependent frictional resistance of a capsule robot inside an intestine. Tribol Lett, 2012, 47: 295–301CrossRefGoogle Scholar
  27. 27.
    Ciarletta P, Dario P, Tendick F, et al. Hyperelastic model of aniso-tropic fiber reinforcements within intestinal walls for applications in medical robotics. Int J Robot Res, 2009, 28: 1279–1288CrossRefGoogle Scholar
  28. 28.
    Gao P, Yan G, Wang Z, et al. Microgroove cushion of robotic endoscope for active locomotion in the gastrointestinal tract. Int J Med Robotics Comput Assist Surg, 2012, 8: 398–406CrossRefGoogle Scholar
  29. 29.
    Cao H, Zhang Y, Han Z, et al. Pole-zero-temperature compensation circuit design and experiment for dual-mass MEMS gyroscope bandwidth expansion. IEEE/ASME Trans Mechatron, 2019, 1Google Scholar
  30. 30.
    Zhang C, Liu H, Li H. Experimental investigation of intestinal frictional resistance in the starting process of the capsule robot. Tribol Int, 2014, 70: 11–17CrossRefGoogle Scholar
  31. 31.
    Jensen M D, Kanaley J A, Reed J E, et al. Measurement of abdominal and visceral fat with computed tomography and dual-energy X-ray absorptiometry. Am J Clinical Nutrition, 1995, 61: 274–278CrossRefGoogle Scholar

Copyright information

© Science China Press and Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • JinYang Gao
    • 1
    • 2
    Email author
  • GuoZheng Yan
    • 3
  • YunBo Shi
    • 1
  • HuiLiang Cao
    • 1
  • Kun Huang
    • 1
  • Jun Liu
    • 1
  1. 1.Science and Technology on Electronic Test and Measurement LaboratoryNorth University of ChinaTaiyuanChina
  2. 2.Shanxi Key Laboratory of Advanced Manufacturing TechnologyNorth University of ChinaTaiyuanChina
  3. 3.Department of Instrument Science and EngineeringShanghai Jiaotong UniversityShanghaiChina

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