A Validation Study of a Computerized Movement Analysis of the Colonoscope in Simulated Colonoscopy

24 physicians are recruited on a voluntarily basis, and will be divided into two groups, based on experience;

1. 12 Novices (0-50 colonoscopies)
2. 12 Experienced (> 140 colonoscopies). The groups are to perform twice on the Endoscopy Training System that is based on four tasks; Scope manipulation, tool targeting, loop management and mucosal inspection. Data for 3D-Colonoscopy Retraction Score (3D-CoRS) will be gathered during the task of mucosal inspection and data for 3D-Colonoscopy Progression Score (3D-CoPS) are collected during loop management.

Novice group:

Any physician who has no experience of endoscopies or has done no more than 50 colonoscopies.

Experienced group:

Includes any physician who have succeeded more than 140 colonoscopies. Professional backgrounds include surgeons and gastroenterologists.

Demographic data will gathered from all three groups as follows:

• Age
• Sex
• Speciality
• Total number of colonoscopies
• Total number of colonoscopies the last year
• Time since graduation
• Experience in simulated endoscopy/colonoscopy The Endoscopy Training System is a simulation system and an assessment tool and includes five different performance metrics and a scoring system. The system is used in combination with an Olympus colonoscope (Olympus Medical Systems Corp. Tokyo, Japan).

Performance metrics:

1. Scope Manipulation (SM) - The use of torque and tip deflection to move a shape in the colon to the 6 o´clock position and align the same shape within an outline placed upon the monitor screen. Before continuing to the next shape, alignment must be held for 5 seconds.
2. Tool Targeting (TT) - 10 targets located around the colon must be found. With a biopsy forceps, each target has to been touched for at least 5 seconds before moving to the next target.
3. Loop Management (LM) - The management of a standard alfa-loop. If during insertion from anus until cecum a loop is formed, it must be first recognised and then unlooped successfully to continue advancing the colonoscope. The Colonoscopy Training Model begin in the left lateral position, but on request, the model can be repositioned in the supine, prone, or right lateral decubitus position. On request, abdominal pressure can be provided when directed by the participant.
4. Mucosal Inspection (MI) - Randomly placed polyps inside the rubber colon have to be found during withdrawal, requiring inspection and retroflexion in the rectum.
5. Retroflexion (RF) - 5 targets located around the anus must be found. With a biopsy forcep, each target has to been touched while the colonoscope is retroflexed in the rectum and touched for at least 5 seconds before moving to the next target.

The 3D-Colonoscopy Progression Score (3D-CoPS) and the 3D-Colonoscopy Retraction Score (3D-CoRS) are movement analysis. Electromagnetic coils are built in along the length of the Olympus colonoscopes. They generate a pulsed low-intensity magnetic field that is picked up a receiver coil. The data-points for each coil are inserted into an algorithm for movement analyzing. This analysis is done as a change between the tip of the scope, and the next tracked magnetic coil. The result is a relative movement of the colonoscope in relation to the previous position, and how much the movement is deflected according to the direction the tip points in. This movement analysis is used for distinction between the progression- and retraction phase, and as the basis for the 3D-CoPS and 3D-CoRS analysis, which is essential, such that the 3D-CoRS measurements is performed during withdrawal of the colonoscope.