Kinematic Modeling and Visual Servo Control of a Soft-Bodied Magnetic Anchored and Guided Endoscope

In minimally invasive surgery (MIS), a number of instruments are inserted into the surgical cavity via the trocar(s), which makes the surgical site crowded and instruments tend to fence with each other. In addition, the motion of the endoscope is restricted by the trocar, which limits the field of view of the endoscope. To alleviate these problems, magnetic anchored and guided systems (MAGSs) have been proposed. Conventional MAGSs are built from rigid materials with small actuators and sensors. As a result, these MAGSs tend to be heavy, complex, difficult to make, and costly. In this article, we first present a soft-bodied MAGS endoscope weighing 13 g, which is made up of printable silicon rubber with embedded magnets and a camera module. The usage of soft 3-D printable material significantly reduces the complexity of the MAGS endoscope. The soft-bodied MAGS endoscope can be anchored and steered by an external magnet controlled by a serial-link robot arm. The kinematic modeling of the soft-bodied MAGS endoscope is developed. Visual servo based automatic instruments tracking of the soft-bodied MAGS endoscope is achieved for the first time. Experimental results validate that the soft-bodied MAGS endoscope can guide surgical instruments, showing its high potentials in MIS.