Low powered uni-directional actuator for wireless active enteroscopy

Wireless capsule endoscopy (WCE) has become the key investigation for early diagnosis of small bowel disorders, displacing all other imaging modalities. However, despite considerable technical progress, the most advanced pills still lack intrinsic controllable locomotion and require large external equipment for magnetic propulsion. Most of the WCE devices simply rely on gravity assisted by peristaltic contraction for transit, thereby incurring the risks of impaction, retention and intestinal obstruction requiring active clinical intervention. The major obstacles to provision of intrinsic of WCE pills stem from size, rigidity, and limited on-board power supply. In this study, we propose the use of vibrations by unidirectional actuator (VIBU) to achieve controlled skid on the slippery small bowel mucosal lining. The VIBU rubber legs are designed and optimized to follow the path in tube or cylindrical internal environment of the small bowel (SB) that provides controlled intrinsic active locomotion. Eventually this concept will replace the rigid WCE pill by a segmented soft highly flexible robot, significantly narrower but longer than current WCE pills. In developing the soft robotic device, two different vibratory mechanisms have been explored. In this paper the micro eccentric rotating mass vibration motor (ERM) is used to demonstrate VIBU functionality by transiting throughout PVC tube and air-filled nylon shelve. The result confirmed that the combination of vibratory mechanism and fixed rubber legs, provide the VIBU with unidirectional propulsion in cylindrical environment.