Design and optimization of soft colonoscopy robot with variable cross section

Background Colonoscopy is the best choice for detecting bowel cancer; its effectiveness and early screening can significantly reduce the incidence rate of bowel cancer. However, the existing colonoscopy procedure is very technically demanding for doctors and painful for patients due to the difficult maneuver of long and slender colonoscope inside human colon. This paper will be focused on designing flexible robots with high dexterity to improve the performance of current colonoscopy. Methods This article optimizes and simulates the shape and layout of the driving cavity of the soft robot, as well as the multi-stage structure. This paper presents a design scheme of the soft robot with variable cross-section. The robot comprises two cross-sections in serial connection, with the outer diameter of the upper section 14mm and the outer diameter of the lower part 16mm. The bending angle and direction of the soft robot can be controlled by adjusting the pressure of the cavity. The soft robot is placed at the end of the traditional colonoscopy, replacing the standard manual operation for guidance during colonoscopy surgery. The relationship between the end position of the actuator and air pressure is calculated by the piecewise constant curvature (PCC) method and verified by subsequent experiments. At the same time, the motion trajectory of the soft robot is further simulated by finite element analysis. Results Experimental verification shows that the bending performance of the newly designed soft robot has significantly improved compared to the old design. Conclusion An improvement was made to address the design shortcomings of traditional actuators, and a new actuator was obtained. The performance of the latest and old actuators was compared through experiments, and it was ultimately known that the new actuator had significantly improved performance compared to the old actuator.