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A
New Endoscopic Simulator Trainees need to perform a certain number of endoscopic procedures to achieve competence. Training on simulators is advantageous because it reduces the number of potentially life-threatening critical mistakes. The change in medical practice that limits education time and patient availability, and the increase in medical legal awareness, have contributed to the greater use of simulators in medical training and education. Simulators are of three types: mechanical, animal, and computer based. Progress in computer technology is expected to promote computer-based simulators. At present, the computer-based simulator is helpful in teaching upper and lower gastrointestinal endoscopy, for diagnostic and some therapeutic procedures. It has been used at workshops and live demonstrations performed during endoscopic meetings. It is predicted that with further technological improvement, training on simulators will become obligatory before performing on humans. Introduction The concept of the simulator as a training tool is well established, notably in aviation [1]. It is also used for the annual evaluation of pilots prior to their final approval by the authorities. The airline industry has demonstrated that the use of such simulators has improved pilot skill [2]. Pilots are trained on simulators in order to reduce mistakes which may be critical and cost lives. It is therefore natural that simulators should be used for training in the medical field as well. In recent years advanced simulation technology has been introduced into medicine in several fields such as laparoscopy [3], cardiology [4, 5], and anesthesiology [6, 7]. Performing an endoscopy requires skill and training. For each type of procedure there is a minimum number of attempts necessary to achieve competence. Different organizations have their recommendations as to the minimal number of procedures needed for competence. It ranges between 100 and 300 for esophagogastroduodenoscopy, 100 - 180 for colonoscopy, and is 100 - 200 for endoscopic retrograde cholangiopancreatography (ERCP) [8 - 11]. Many supervising physicians find that they have insufficient time to spend overseeing procedures. Any device which saves time would be valuable. The most obvious example of such a device would be an endoscopic simulator, which would enable the trainee to learn and be tested quickly and safely. Mechanical Simulators Historically, the first endoscopic simulators were mechanical models. Particular interest has focused on flexible Sigmoidoscopy and colonoscopy [12 - 13]. Devices used have ranged from a simple slide-projection system to a rubber model of the colon. The most advanced mechanical model available at the present time is the model developed by the university hospital of Tübingen. Unfortunately, most models of the upper and lower gastrointestinal tract have been inappropriate for training, and the level of trainee interaction has been negligible. Animal Models Animal models are more realistic, but they require a continuous search for animals, and ethical objection is likely to limit their availability. It is for those reasons that the exteriorized dog colon used for colonoscopy [14] and the porcine models used for ERCP and sphincterotomy [15, 16] have not gained popularity. An exception is the Erlangen model known as EASIE (Erlangen Active Simulator for Interventional Endoscopy) or the Erlangen Endo-Trainer [17] in which the gastro-intestinal tract and the pancreaticobiliary system are obtained from slaughtered pigs. An ingenious perfusion system generates realistic bleeding episodes. It allows the performance of most gastrointestinal procedures in a realistic fashion, in conditions very similar to those encountered in a human. Computer-Based Simulators There is presently only one computer-based simulator
of the gastrointestinal tract, the GI-Mentor, which was developed
by a company by the name of Simbionix (Tel Hashomer, Israel). HT
Medical Systems (Gaithersburg, Mary-land, USA) is another company
that has developed a computer-based simulator for bronchoscopy and
plans to enter the field of gastroenterology as well. |
Figure 1 The GI-Mentor, showing
the mannequin, the endo-scope,
the computer with the shape of a light source, and the screen
The Simbionix simulator is based on the production of a three-dimensional
geometric model. The texture of the gastrointestinal tract is videotaped
during a real endoscopic procedure and manipulated by computer as needed.
There is global and local deformity, i. e. a change either in the entire
configuration of the gastrointestinal tract due to the insertion of the
endoscope, or in the gastrointestinal wall due to local pressure from
an endoscope or tools. The computer stores information related to the
movement of the endo-scope from the beginning of the procedure. Information
about the location of the endoscope is transmitted from sensors located
on the endoscope. The force feedback (the resistance encountered) is based
on both the motion model and the characteristics of the gastrointestinal
tract [18].
The Simbionix simulator is a real-time interactive computerized
simulator that replicates both diagnostic and therapeutic procedures.
The procedure is performed on a mannequin using a real Pentax endoscope.
Steering and torque of the endoscope is therefore possible and there are
suction and inflation buttons as well (Figure 1). Hardware and soft-ware
are combined to simulate the sensation of performing real endoscopic procedures.
The endoscope (customized by Simbionix) is inserted into the mannequin,
equipped with a special controlled force-feedback device. This device
provides trainees with realistic sensations that replicate actual endoscopic
examinations. Trainees receive the force-feed-back sensations with simultaneous
visual feedback displayed on an attached monitor. The simulator includes
upper and lower gastrointestinal cases, with a gradual increase in difficulty
of performance as the anatomy becomes more difficult and the pathology
rarer. These cases represent realistic scenarios of patient situations
(Figures 2, 3).
Figure 2 A colon with a polyp
Figure
3 Ischemic colitis of the sigmoid
colon
Simbionix offers a collection of patient cases that can be organized into customized tutorials. These cases are designed to reflect real-life situations that could be encountered in a hospital environment. Each case begins with a case history and allows the trainees to practice examinations and operations appropriate for the case. Once a trainee has completed an assigned tutorial session, instructors can view the events recorded during the performance. Comments can be entered in the trainee file and special notes can be sent to the trainee using a message facility.
A special Internet connection allows instructors to connect to the simulator from any remote location, as long as the application is installed and the computer is equipped with a modem. This allows the instructor to monitor trainee performance, assign programs, and send messages in real time from any location at his convenience. In addition, the Simbionix Internet site offers new case modules which can be downloaded directly into the system for immediate use.
The Simbionix simulator has been used at exhibitions and workshops during the last year. At endoscopic workshops, it has been used by experts in live demonstrations for teaching purposes, and by less experienced endoscopists during training sessions.
In the last two workshops held in Nice and in Hamburg (Endo club Nord), 71 gastroenterologists with more than 1 year's experience in performing endoscopy filled out evaluation questionnaires following their time on the GI-Mentor simulator. 96 % felt that the simulator met their expectations and 83 % considered that it would be advantageous to be trained in an institution where such a simulator existed. 81 % would use the simulator in their next training program if it were available, and 90 % felt that prior training on the GI-Mentor would reduce potential risk to patients. The simulator was considered user friendly by 97 %, and 88 % would recommend it to others. A validation study is on its way, in which trainees will be randomly allocated to two groups, one trained using a simulator and the other trained without a simulator.
The Future
Bearing in mind the simulators already available, the increased public awareness of medical legal issues, and the limited time of supervising physicians, endoscopic training is likely to undergo changes. Trainees will start their training on a computer-based simulator. Since it is always available, the trainee can practice for as long as is needed and at the time convenient for him. The virtual mentor that exists in such a simulator will constantly improve the trainee's performance. The Simbionix simulator is ideal for this purpose.
More advanced training in therapeutic procedures can be done with the Erlangen model. However, the use of such a model requires early planning. The pig stomach or colon needs to be obtained and prepared. It is therefore expected that such training will be integrated into special workshops. In the very near future the computer-based simulator will provide the option for therapeutic procedures as well. Once this happens, the need for animal models is expected to decline. In addition, as with flight simulators, computer-based simulators will make continuous monitoring of competence possible. Accurate recording of successes and failures throughout professional life would help individuals recognize areas where they need improvement, and would also help healthcare organizations to identify impaired practitioners.
Acknowledgments
The author thanks Ms Edna Chosack and Dr Mira Barki for their help in preparing the manuscript.
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18 Simbionix Inc. Product brochure. 1999 Corresponding Author S. Bar-Meir,
M.D. Dept. of Gastroenterology Chaim Sheba Medical Center Tel Hashomer
and Sackler School of Medicine 52621 Tel Hashomer, Israel Fax: + 972-3-530-2913
E-mail: barmeir@netvision.net
Endoscopy 2000; 32 Bar-Meir S 900
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