Research on anchoring and actuation of a novel magnetically driven laparoscopic robot

This article introduces a new prototype of a magnetic-driven capsule robot. The design utilizes the idea of nonlinear magnetic field motion coupling to achieve four degrees of freedom motion of the capsule robot. Transmission of force and torque between an external driving device and an internal camera device through magnetic field coupling and the internal camera's anchoring and rotation functions are achieved by an external rotating magnetic field. As the motion and posture control of the capsule robot are entirely controlled by six permanent magnets, we use a 3D printer to print a resin shell to hold two square permanent magnets, and an external stepper motor is used to control the rotational motion of the annular permanent magnet in the external device to drive the posture control of the capsule robot's head movement device. The overall width and length of the capsule robot are 25mm and 108mm, respectively, meeting the minimum incision size for laparoscopic minimally invasive surgery. To validate the feasibility of the capsule robots, we used a nylon board as the human abdominal cavity (their magnetic permeability is approximately 1). We completed a four-degree-of-freedom control experiment of capsule robots in an open environment and verified the stable tilt angle error of the capsule robot to be within 0.1°. This demonstrated the feasibility of the new magnetic-controlled robot in obtaining stable images during actual single-port laparoscopic surgery.