Design and Preliminary Evaluation of an Electromagnetically Actuated Soft-Tethered Colonoscope

Colorectal cancer (CRC) incidence has been steadily rising worldwide. Early screening and treatment by colonoscopy are critical in reducing both the incidence and mortality rate of CRC. The conventional flexible colonoscope (FC) requires high skills of the physicians and may lead to patient discomfort. Many novel techniques for colonoscopy have been developed, each of which has its own pros and cons. This paper proposes an electromagnetically actuated soft-tethered (EAST) colonoscope system to provide an alternative solution. The EAST colonoscope is competent in achieving complete functions of FC and reducing patient discomfort owing to the gentle interaction between the colonoscope and colon wall. Physical experimentation is conducted with a proof-of-concept actuation prototype to validate the feasibility of the EAST colonoscope. The experimental results show that the orientation can be controlled to follow the desired trajectories with a mean absolute error of 0.302 mm. Moreover, the system is demonstrated to achieve active locomotion and orientation in a colon phantom, while other operations such as insufflation, biopsy, and drug delivery are performed using a porcine colon, which indicates that the EAST colonoscope delivers high potentials in medical application.