Tribology Letters

, Volume 47, Issue 2, pp 295–301 | Cite as

Modeling of Velocity-dependent Frictional Resistance of a Capsule Robot Inside an Intestine

  • Cheng Zhang
  • Hao LiuEmail author
  • Renjia Tan
  • Hongyi Li
Original Paper


A model is first built for predicting the velocity-dependent frictional resistance of a capsule robot that moves inside the intestine in the paper. The capsule robot plays a more and more important role in checking diseases in the intestine. This study aims to optimize the locomotion mechanism and the control strategy of the capsule robot. The model consists of three parts: environmental resistance, viscous friction, and Coulomb friction. Environmental resistance is induced by the stress due to the viscoelastic deformation of the intestinal wall. Viscous friction is analyzed according to the apparent viscosity of intestinal mucus. Coulomb friction is a product of the local contact pressure and the Coulomb friction coefficient. In order to analyze the effects of the intestinal deformation, a five-element model is used to describe the stress relaxation of the intestinal material. Experimental investigation is used to identify the model parameters with homemade physical simulation measurement system and fixtures. Finally, the model’s validity is verified by experimental results. It is shown that the model predicting results can fit the experimental results well when the moving velocity of the capsule is lower than 20 mm/s. The R 2 of these two sets of data is 0.8769. But at a higher velocity, there are significant differences between the two results and the R 2 declines to 0.1666. The friction model is expected to be useful in the development of the medical equipment in the intestine and the study of biomechanics of the intestine.


Friction model Velocity-dependent Intestine Viscoelasticity 



This study was supported by the National Technology R&D Program of China, under the Contract Number 2012BAI14B03 and Project 61105099 supported by National Natural Science Foundation of China.


  1. 1.
    Munoz-Navas, M.: Capsule endoscopy. World J. Gastroenterol. 15(13), 1584–1586 (2009)CrossRefGoogle Scholar
  2. 2.
    Saruta, M., Papadakis, K.A.: Capsule endoscopy in the evaluation and management of inflammatory bowel disease: a future perspective. Expert Rev. Mol. Diagn. 9(1), 31–36 (2009)CrossRefGoogle Scholar
  3. 3.
    Carey, E.J., Leighton, J.A., Heigh, R.I., Shiff, A.D., Sharma, V.K., Post, J.K., Fleischer, D.E.: A single-center experience of 260 consecutive patients undergoing capsule endoscopy for obscure gastrointestinal bleeding. Am. J. Gastroenterol. 102(1), 89–95 (2007)CrossRefGoogle Scholar
  4. 4.
    Wang, K., Wang, Z., Zhou, Y., Yan, G.: Squirm robot with full bellow skin for colonoscopy. In: Proceedings of the 2010 IEEE International Conference on Robotics and Biomimetics, pp. 53–57 (2010)Google Scholar
  5. 5.
    Quaglia, C., Buselli, E., Webster, R.J., Valdastri, P., Menciassi, A., Dario, P.: An endoscopic capsule robot: a meso-scale engineering case study. J. Micromech. Microeng. 19(10), 11 (2009)CrossRefGoogle Scholar
  6. 6.
    Yang, W.A., Hu, C., Meng, M.Q.H., Dai, H.D., Chen, D.M.: A new 6D magnetic localization technique for wireless capsule endoscope based on a rectangle magnet. Chin. J. Electron. 19(2), 360–364 (2010)Google Scholar
  7. 7.
    Gao, M., Hu, C., Chen, Z., Zhang, H., Liu, S.: Design and fabrication of a magnetic propulsion system for self-propelled capsule endoscope. IEEE Trans. Biomed. Eng. 57(12), 2891–2902 (2010)CrossRefGoogle Scholar
  8. 8.
    Wang, X., Meng, Q.H., Chen, X.: A locomotion mechanism with external magnetic guidance for active capsule endoscope. In: Engineering in Medicine and Biology Society (EMBC), 2010 Annual International Conference of the IEEE, pp. 4375–4378 (2010)Google Scholar
  9. 9.
    Kim, B., Park, S., Park, J.O., IEEE: Microrobots for a capsule endoscope. In: IEEE ASME International Conference on Advanced Intelligent Mechatronics, pp. 729–734 (2009)Google Scholar
  10. 10.
    Hoeg, H.D., Slatkin, A.B., Burdick, J.W., Grundfest, W.S.: Biomechanical modeling of the small intestine as required for the design and operation of a robotic endoscope. In: Proceedings of IEEE International Conference on Robotics and Automation, pp. 1599–1606 (2000)Google Scholar
  11. 11.
    Li, J., Huang, P., Luo, H.D.: Experimental study on friction of micro machines sliding in animal intestines. Lubr. Eng. 175(3), 119–122 (2006)Google Scholar
  12. 12.
    Baek, N.K., Sung, I.H., Kim, D.E.: Frictional resistance characteristics of a capsule inside the intestine for microendoscope design. Proc. Inst. Mech. Eng. H 218(3), 193–201 (2004)CrossRefGoogle Scholar
  13. 13.
    Kim, J.S., Sung, I.H., Kim, Y.T., Kwon, E.Y., Kim, D.E., Jang, Y.H.: Experimental investigation of frictional and viscoelastic properties of intestine for microendoscope application. Tribol. Lett. 22(2), 143–149 (2006)CrossRefGoogle Scholar
  14. 14.
    Kim, J.S., Sung, I.H., Kim, Y.T., Kim, D.E., Jang, Y.H.: Analytical model development for the prediction of the frictional resistance of a capsule endoscope inside an intestine. Proc. Inst. Mech. Eng. H 221(H8), 837–845 (2007)Google Scholar
  15. 15.
    Wang, X., Meng, M.Q.H.: An experimental study of resistant properties of the small intestine for an active capsule endoscope. Proc. Inst. Mech. Eng. H 224(H1), 107–118 (2010)Google Scholar
  16. 16.
    Wang, K.D., Yan, G.Z.: Research on measurement and modeling of the gastro intestine’s frictional characteristics. Meas. Sci. Technol. 20(1), 015803.1–015803.6 (2009)CrossRefGoogle Scholar
  17. 17.
    Li, H., Katsuhisa, F., Chernousko, F.L.: Motion generation of the capsubot using internal force and static friction. In: 45th IEEE Conference on Decision and Control, pp. 6575–6580 (2006)Google Scholar
  18. 18.
    Gregersen, H.: Biomechanics of the Gastrointestinal Tract: New Perspectives in Motility Research and Diagnostics, 1st edn. Springer, New York (2003)Google Scholar
  19. 19.
    Tan, R., Liu, H., Su, G., Zhang, C., Li, H., Wang, Y.: Experimental investigation of the small intestine’s viscoelasticity for the motion of capsule robot. In: IEEE International Conference on Mechatronics and Automation, ICMA 2011, pp. 249–253 (2011)Google Scholar
  20. 20.
    Wu, J.H., Cheng, X.Y., Wei, Y.L., Zhou, Y.S., Zhu, Y.Q.: Rheological behavior of dog’s small intestinal mucus. J Chongqing Univ (Natural Science Edition) 23(2), 10–12 (2000)Google Scholar
  21. 21.
    Varum, F.J.O., Veiga, F., Sousa, J.S., Basit, A.W.: An investigation into the role of mucus thickness on mucoadhesion in the gastrointestinal tract of pig. Eur. J. Pharm. Sci. 40(4), 335–341 (2010)CrossRefGoogle Scholar
  22. 22.
    Zhang, C., Su, G., Tan, R., Li, H.: Experimental investigation of the intestine’s friction characteristic based on “internal force-static friction” capsubot. In: IASTED International Conference on Biomedical Engineering, Biomed 2011, pp. 117–123 (2011)Google Scholar
  23. 23.
    Ciarletta, P., Dario, P., Tendick, F., Micera, S.: Hyperelastic model of anisotropic fiber reinforcements within intestinal walls for applications in medical robotics. Int. J. Robot. Res. 28(10), 1279–1288 (2009)CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  1. 1.State Key Laboratory of RoboticsShenyang Institute of Automation (SIA)ShenyangChina
  2. 2.Graduate University of the Chinese Academy of SciencesBeijingChina

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