Fabrication of Magnetically Driven Biopsy Mechanism Applicable to Capsule-Type Medical Device.

This article proposes two kinds of magnetic rotary actuators applicable to a next-generation capsule endoscope that can conduct a small intestinal biopsy. One actuator is for an anchoring mechanism that can stop the capsule in a specific place against the peristaltic movement of the small intestine, and press a biopsy instrument on a lesion. The other actuator is for a biopsy mechanism that can project a circular blade while rotating, and obtain a tissue sample. Both actuators have the same basic structure, which is composed of a bolt with a permanent magnet and a nut, and can be driven by a rotating magnetic field. Because they are arranged orthogonally to each other in the capsule, they can be individually operated by the corresponding rotating magnetic field. Given the results of an operational test similar to an actual environment in a porcine small intestine, these actuators could successfully perform the desired operation.