Soft Colonoscopy Robot Could Revolutionize Routine Screening

A new study describes how a prototype robotic probe that adapts to the colon’s anatomy could enable hospitals to perform screening colonoscopies without expert supervision.

Developed at the University of Nebraska Lincoln (UNL, USA), the semi-autonomous colonoscopic robot uses a minimally invasive locomotion approach that takes advantage of longitudinal expansion of an inflatable latex tube in order to propel the robot’s tip along the colon. Similar to an inflating balloon, the tube adjusts itself and makes its way into the colon as it expands out of a fixture placed in the anus. The robot creates less than 6 Newton of normal force at its tip when pressurized at 90 kPa, generating a maximum force of just 44.17 mmHg, significantly lower than the safe intraluminal human colonic pressure of 80 mmHg.

The robot design inherently prevents loop formation in the colon, which is recognized as the main cause of post procedural pain in patients. In ex-vivo experiments, the robot successfully advanced 1.5 meters inside an excised curvilinear porcine colon with average speed of 28 mm/sec, traversing four 90-degree curves to reach the cecum in just 54.2 seconds, compared to 15.9 minutes using traditional colonoscopy, and a minimum of 4.9 minutes by an experienced colonoscopist. The study was published in the April 2017 issue of Journal of Medical Engineering & Technology.

“In traditional colonoscopy, the colonoscope deforms the colon; it’s really hard to navigate something inside the colon from outside the body. Our robot is self-propelling, self-steering and it complies itself with the shape of the colon,” said lead author biomedical engineer Hossein Dehghani, PhD. “The proposed robotic approach allows physicians to concentrate mainly on the diagnosis, rather than the mechanics of the procedure.”

Colonoscopy is the endoscopic examination of the colon and the distal part of the small bowel with a video or fiber optic camera on a flexible tube passed through the anus. It may provide a visual diagnosis (e.g. ulceration, polyps) and grants the opportunity for biopsy or removal of suspected lesions. Virtual colonoscopy, which uses imagery reconstructed from computed tomography (CT) scans or from nuclear magnetic resonance (MR) scans, is also possible, although it is not standard and still under investigation regarding its diagnostic abilities.

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