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Development of an Efficient Locomotion Mechanism for Wireless Active Capsule Endoscope Sponsored by Shun Hing Institute of Advanced Engineering Max Q.-H. Meng*, James Y.-W. Lau#, and Xiaona Wang* |
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Introduction Diseases of the Gastrointestinal (GI) tract, such as stomach and colon cancers and ulcerative colitis, are common in most countries. According to the statistics of the Hong Kong Cancer Registry in 2007, the bowel cancer caseload in Hong Kong ranked second of all and it’s approaching the highest. In 2005, there were 3706 individuals that newly developed cancer in the large bowel. Most GI related cancers can be cured if they are detected at their early stages. Endoscopy is the most popular method for GI tract examination because it enables diagnosis based on analysis of real images and biopsy samples. Wireless capsule endoscope, which is equipped with a micro-camera and wireless communication capability, eliminates the patients’ pain and provides a relatively effective way to examine the small intestine. However, since the movement of the passive capsule is not controlled, missing diagnosis is possible and extended observation of interested spots along the GI tract is impossible. To tackle the problems associated with current wireless capsule endoscopes, we will design the next generation wireless active capsule endoscope with a locomotion mechanism for controlled interactive GI tract examination. The developed device can be controlled to examine and stop at any interested spots of the GI tract and can be guided to move through unimportant areas of the GI tract in a much faster pace than the passive natural human peristaltic GI movement, so that it will have the advantages of both the conventional wired endoscopes and the wireless passive ones. It is a better endoscopy that is easy, safe, and comfortable to use, controllable and precise, with less examination time and with significantly reduced missing spots. The overall objective of this proposed research is to develop a new wireless active capsule endoscope with active locomotion capability for controlled interactive examination and diagnosis of the human GI tract. The active capsule endoscope will also serve as a platform for related future development, such as active devices for internal surgical operations, internal medicine delivery and application, and biopsy, among many others.
Objectives 1. Study on next-generation active capsule endoscopeThe swallowable capsule endoscope represented by the M2A (now PillCam) capsule is easy and safe. However, due to its passive and uncontrollable movement, it usually takes 8-24 hours to go through the entire GI tract and it is possible for it to miss diseased spots on the GI tract. To tackle the problem, in the proposed project we will develop a locomotion mechanism for the capsule endoscope. The proposed active capsule endoscope with a locomotion mechanism can be controlled by the doctor to interactively examine and arbitrarily orient the capsule at any interested spots of the human GI tract. 2. Investigation of the resistant properties of the small intestine This is necessary for the design of an internal actuator that can propel itself inside the GI tract efficiently. The intestinal tissue is flexible and there are mucous substances on the inner wall of the intestinal tract, which makes its resistant properties quite different from a solid material. The shape of the capsule and pattern of the surface material will be studied to reduce the drag or increase the friction as appropriate. Mathematical models will be developed and parameters will be identified. 3. Development of an actuator for the locomotion mechanism An integrated actuator will provide driving force for the capsule endoscope to move. Because of the constraints of the capsule size and the internal power supply, the locomotion system should be miniaturized and integrated on-board the capsule. In addition to the internal actuation, the design will also take advantage of external magnetic force from the available external capsule localization magnetic field to further expand the actuation capability. 4. Development of a clamper for the locomotion mechanism Because of the slippery inner surface of the small intestine, a locomotion mechanism without a clamper will be very difficult to move forward. The clamper will work with the friction to assist the actuator to generate a forward force. The clamper will be developed using patterned materials with increased friction coefficient and controlled via the external magnetic field to save internal energy. 5. Development of a working prototype of the self-actuated capsule The proposed project will develop a self-actuated active wireless capsule endoscope prototype for further experimental study. The working prototype will contain a miniaturized on-board integrated locomotion system with a control system. In addition, extensive in-vitro experimental studies will be carried out for possible future in-vivo animal tests.
Impact This project will lead to an efficient locomotion system for next-generation active capsule endoscopes. The developed system will enable the capsule endoscopy with easier, safer, more comfortable, and controlled interactive examination with less time and reduced missing spots. The technologies and prototypes developed from this project will offer Hong Kong and China medical devices and equipment industries the unique opportunity to manufacture and market the wireless active capsule endoscopes and will help to better equip China health care communities to provide painless, state-of-the-art services to the needy patients in China.
Members of the research team: Max Q.-H. Meng - Professor, Department of Electronic Engineering, CUHK James Y.-W. Lau - Professor, Department of Surgery, CUHK Xiaona Wang - Post-Doctoral Fellow, Department of Electronic Engineering, CUHK Li-Sheng Xu - Post-Doctoral Fellow, Department of Electronic Engineering, CUHK |