Untethered Robotic Motion and Rotating Blade Mechanism for Actively Locomotive Biopsy Capsule Endoscope

Capsule endoscopy (CE) is a convenient and promising alternative endoscopic method for the gastrointestinal diagnostics on clinical sites; however, multifunctional utilization with active targeting locomotion is still challenging due to internal power limitations and micro-size manipulation mechanisms. The biopsy is one of the most demanding functions of intestinal CE, and successful developments could significantly improve the intestinal diagnostics for precise decisions and comfortable usage. In this paper, we present a novel active locomotive robotic biopsy capsule endoscope using an externally driven electromagnetic actuation (EMA) system and a battery-free wireless rotating blade mechanism. The external magnetic field from the EMA system controls both locomotion and biopsy operation, and thus, the proposed mechanism does not consume the internal power of the CE. We prototyped the proposed biopsy module and integrated it into an active locomotive capsule endoscope. Simulations were conducted to design the module and analyze the magnetic responses. We performed experiments with the biopsy capsule endoscope both in vitro and ex vivo to demonstrate its feasibility. In conclusion, the prototyped robotic biopsy capsule endoscope could successfully perform the necessary movements for the capsule in the small intestine and perform a biopsy at the target lesion with sufficient force. The amount of biopsy tissue was sufficient for a histological examination.