In vitro evaluation of forces exerted by a new computer-assisted colonoscope (the NeoGuide Endoscopy System)

Background: The NeoGuide Endoscopy System (NES) utilizes a fully articulated, computer-controlled insertion tube that allows proximal segments of the colonoscope to follow the path taken by the tip as it is manually advanced through the colon. The system was designed to eliminate looping and scope displacement during colonoscopy. Material and methods: Using in vitro testing, an inanimate flexible model of the colon incorporating four force transducers located at the key flexure points was employed to measure the axial forces on the colon wall during colonoscopy. In the second part of the study, 10 gastroenterologists performed colonoscopies, using a training latex-based simulator, with the NES and-with a standard colonoscope. Colonic displacement was independently assessed by six gastroenterologists, with each evaluating endoscopist assigning a score between 0 and 5 corresponding to the maximum colonic displacement observed at any location. Results: The average measured forces (in lbs) at three of the four flexure points were significantly lower (P < 0.05) when the NES was used. The mean colonic displacement was significantly lower for procedures performed with the NES compared with the standard colonoscope (2.36 vs. 4.26, P < 0.001). Interobserver agreement regarding the degree of colonic displacement due to looping was moderate (weighted kappa = 0.45, P < 0.01). Conclusions: Colonoscopy with the NES was associated with significantly less looping and lateral force required for advancement than procedures with a standard colonoscope. The reduced amount of looping suggests that use of the NES in patients might be associated with less discomfort and thus require less sedation.