Gastroenterology

Background: The Colonoscopy Force Monitor (CFM) is a wireless handheld device that continually measures linear and rotational forces applied to the colonoscope insertion tube during a colonoscopy. Previous studies demonstrated significant variation among endoscopists in magnitude and pattern of force application in humans. The purpose of this study was to determine if the Kyoto-Kagaku colonoscopy training model could be used to identify differences in force application patterns between attending and trainee endoscopists using a simple or complex colon loop case model. Methods: Eight endoscopists, attending, 1st, 2nd and 3rd yr trainees, performed colonoscopy with a newly designed CFM4 on the Kyoto-Kagaku training model. This model allows for the creation of colonoscopy training scenarios of increased complexity: case 1 represents an introductory level without loop and case 5 a secondary level with a redundant sigmoid and alpha loop. Each physician performed a total of 6 procedures with 3 consecutive replicates for each case model. Continuous CFM4 data were recorded and the following force parameters calculated for each procedure: maximum and average push, pull, clockwise and counter clockwise torque; average push, pull, clockwise and counter-clockwise torque rate; maximum combined force and clockwise and counter-clockwise torque vector; and exam time. Results: Increasing case difficulty resulted in a significant increase in applied force and exam time. For example, average pull force was Ϫ7.1 Ϯ 2 . 4Nv sϪ9.9 Ϯ 3 . 5N( p Ͻ0.01), average clockwise force torque rate was 0.19 Ϯ 0.03 N/s vs 0.23 Ϯ 0.03 N/s (pϽ0.001), and exam time was 137 vs 229 sec (pϽ0.005) for case 1(Easy) and case 5(Difficult), respectively. ANOVA of case replicates demonstrated significant differences in selected force parameters including maximum push force (pϽ0.01) maximum clockwise and counterclockwise torque (pϽ0.02), average counter-clockwise torque (pϽ0.003) as the endoscopist repeated the procedure on the same case model. For example,