Earthworm-based miniature robot for intestinal inspection

As a part of MIS (Minimally Invasive Surgery), the endoscope plays an important role in the field of diagnosis and treatment. To combine a miniature robot with an endoscope is a new dimension in the field of medical robotics in recent years. Overcoming the shortcomings of the traditional endoscope, robotic endoscope applies new materials and technologies into the design of a endoscope and booms the development of a new type of endoscope. In this paper, an earthworm based electromagnetic robotic endoscope system is introduced whose structure and locomotion mechanism are analyzed. The motion characteristics in time and frequency domain of a single component are also discussed in detail and a modified waveform and a suitable driving frequency are put forward through which an effective movement control can be achieved and the heat generation of the robot reduced. The robot, 7mm in diameter, 64mm in length and 9.8g in weight, is small enough to pass through the neck of intestine easily and flexible enough (gimbal mounts of 2 degree of freedom) to wind through the intestine. Though the running of the robot is good, there are still problems, such as heat generation and locomotion mechanism on the inner intestinal surface, to be solved.