Capsule type medical robot with magnetic drive in abdominal cavity

This paper describes the development of a medical robot that remains in the abdominal cavity in order to monitor sites of medical interest, and discusses robot travel operations and specifications. A long and narrow piece of ferromagnetic material was placed inside the robot, after which an external magnetic field was used to set the robot in motion. We developed a prototype robot, and conducted experiments in order to verify our proposed concept and the drive principles of the robot. In vivo experiments in a rabbit model showed that solenoids produced sufficient magnetic force to enable the robot to travel through the abdominal cavity, verifying the motion principles. The appropriate shape of the robot was confirmed in the experiments, and the friction between the robot and the organs and the abdominal wall was measured. Using a modified prototype of the robot, we conducted clinical experiments in the rabbit model in which a surgeon operated the XYZ axis stages in order to adjust the position of the subject for the experiment and moved the robot to the liver. Robot travel from the insertion point to the liver was verified on X-rays. The long travel distance of the robot was enabled by its improved shape and through the use of accurate magnetic field imaging.