Comparing endoscopic systems on two simulated tasks.

Endoscopes are slender instruments for performing medical procedures\ud through small incisions or natural body orifices. Three experiments examined\ud the performance effects of various endoscope systems when naive participants\ud executed tasks in a bladder-like environment. The systems involved a direct\ud endoscope, requiring the user to look through a lens at the outer part of the\ud endoscope, and a video endoscope that picks up the image via a camera\ud attached to the endoscope and displays it on a video monitor. The results\ud indicate that the participants performed the tasks better with video than with\ud direct endoscopes, and showed more transfer of practice with video\ud endoscopic surgery from a small to a large task environment than vice versa.\ud The optimal position of the monitor with video endoscopic surgery appeared\ud to involve a reasonable angle relative to the operating area (458 was used).\ud Performance was less at a greater angle (908), but also at a small angle (108).\ud It did not matter whether the monitor was located left, right or above the\ud operating area. As performance did not fully transfer to differently sized task\ud environments, endoscopists should initially train with task environments of\ud different, and especially small, sizes