Evaluation of a virtual endoscopy simulator for training in gastrointestinal endoscopy

Lessons learned from the operating room about procedure efficiency

The driving force for increasing efficiency in most endoscopy suites is to accommodate the flood of patients requiring screening colonoscopy. It is likely that in the next 5 to 10 years, another, less invasive screening test, will replace this demand. This article reviews some of the lessons learned from surgeon's and anesthesiologist's efforts to improve operating room (OR) efficiency and suggests ways to apply this information to running the endoscopy suite.

Learning curves and impact of psychomotor training on performance in simulated colonoscopy: a randomized trial using a virtual reality endoscopy trainer

BACKGROUND

The aim of this study was to analyze the learning curve for the GI Mentor II endoscope trainer and to determine whether psychomotor training can contribute to an improvement in the performance of virtual colonoscopy.

METHODS

To analyze the learning curve, 28 subjects were divided into three groups on the basis of their experience with gastrointestinal (GI) endoscopy: experienced surgeons (group 1, performed > 200 endoscopic procedures, (n = 8)) residents (group 2, performed < 50 endoscopic procedures, (n = 10)); and medical students (group 3, never performed GI endoscopy, (n = 10)). The participants were tested on the GI Mentor II virtual reality simulator 10 consecutive times. Assessment of the learning curve was based on the following three parameters: time used, number of punctured balloons, and number of wall collisions. In the second part of the study, 20 subjects who had never performed GI endoscopy were included. After performing a virtual colonoscopy, they were randomized to a group that received psychomotor training and a control group. Finally, all subjects performed a virtual colonoscopy. Assessment of endoscopic skills during the colonoscopy was based on nine parameters dealing with psychomotor skills.

RESULTS

The learning curve for time expended reached a plateau after the second repetition for group 1 (Friedman's test, p < 0.05), after the fifth repetition for group 2 (p < 0.05), and after the seventh repetition for group 3 (p < 0.05). Experienced surgeons did not improve their scores for regarding number of balloons punctured or number of wall collisions (p > 0.05), indicating the absence of a learning curve for these parameters. Group 2 improved their scores up to the fourth and fifth repetitions, respectively (p < 0.05), and group 3 up to the fifth and seventh repetitions, respectively (p < 0.05). Experienced surgeons achieved the best performance, followed by group 2 and then group 3. The surgeons who had received psychomotor training performed the second virtual colonoscopy significantly faster than the control group (Mann-Whitney test, p < 0.001) and made significantly greater improvement in all other parameters as well.

CONCLUSIONS

There were different learning curves for surgeons depending on their endoscopic background. The familiarization rate on the simulator was proportional to the endoscopic experience of the surgeons. Psychomotor training had a significant effect on the performance of a simulated colonoscopy.

Training with a computer-based simulator achieves basic manual skills required for upper endoscopy: a randomized controlled trial

BACKGROUND

Changes in medical practice have constrained the time available for education and the availability of patients for training. Computer-based simulators have been devised that can be used to achieve manual skills without patient contact. This study prospectively compared, in a clinical setting, the efficacy of a computer-based simulator for training in upper endoscopy.

METHODS

Twenty-two fellows with no experience in endoscopy were randomly assigned to two groups: one group underwent 10 hours of preclinical training with a computer-based simulator, and the other did not. Each trainee performed upper endoscopy in 19 or 20 patients. Performance parameters evaluated included the following: esophageal intubation, procedure duration and completeness, and request for assistance. The performance of the trainees also was evaluated by the endoscopy instructor.

RESULTS

A total of 420 upper endoscopies were performed; the computer pretrained group performed 212 and the non-pretrained group, 208. The pretrained group performed more complete procedures (87.8% vs. 70.0%; p < 0.0001), required less assistance (41.3% vs. 97.9%; p < 0.0001), and the instructor assessed performance as "positive" more often for this group (86.8% vs. 56.7%; p < 0.0001). The length of procedures was comparable for the two groups.

CONCLUSIONS

The computer-based simulator is effective in providing novice trainees with the skills needed for identification of anatomical landmarks and basic endoscopic maneuvers, and in reducing the need for assistance by instructors.

Computer-assisted diagnosis system in digestive endoscopy

The purpose of this paper is to present an intelligent atlas of indexed endoscopic lesions that could be used in computer-assisted diagnosis as reference data. The development of such a system requires a mix of medical and engineering skills for analyzing and reproducing the cognitive processes that underlie the medical decision-making process. The analysis of both endoscopists experience and endoscopic terminologies developed by professional associations shows that diagnostic reasoning in digestive endoscopy uses a scene-object approach. The objects correspond to the endoscopic findings and the medical context of examination and the scene to the endoscopic diagnosis. According to expert assessment, the classes of endoscopic findings and diagnoses, their primitive characteristics (or indices), and their relationships have been listed. Each class describes an endoscopic finding or diagnosis in an intensive way. The retrieval method is based on a similarity metric that estimates the membership value of the case under investigation and the prototype of the class. A simulation test with randomized objects demonstrates a good classification of endoscopic findings. The correct class is the unique response in 68% of the tested objects, the first of multiple responses in 28%. Four descriptors are shown to be of major importance in the classification algorithm: anatomic location, shape, color, and relief. At the present time, the application database contains approximately 150 endoscopic images and is accessible via Internet. Experiments are in progress with endoscopists for the validation of the system and for the understanding of the similarity between images. The next step will integrate the system in a learning tool for junior endoscopists.

VIRTUAL VITREORETINAL SURGICAL SIMULATOR AS A TRAINING TOOL

OBJECTIVE

To demonstrate the feasibility and potential applicability of a virtual reality simulator for vitreoretinal surgery as a training and/or assessment tool.

METHODS

The subjects of this study included medical students, ophthalmologic residents, and trained vitreoretinal surgeons. There were three study groups. Group I comprised 22 subjects who performed a navigation task. The time to complete the task was recorded. The relationship between the completion time, experience, and stereopsis was evaluated. Group II included 6 subjects who consecutively performed the navigation task to evaluate their learning curve. Group III included 16 subjects who performed the membrane peeling task. The number of retinal contacts and the completion time were recorded. The relationship between experience and stereopsis with the number of contacts and the completion time were evaluated.

RESULTS

The average completion time in Group I for students, residents, and trained surgeons was 121.6, 92.5, and 70.6 seconds. There was a significant difference between students and trained surgeons (P = 0.004). In Group II, there was a significant decrease in the completion time with training (P = 0.001). In Group III, the average completion time for students, residents, and trained surgeons was 197, 144, and 118.2 seconds; the respective number of retinal contacts was 14, 8, and 3. There was a significant difference between students and residents (P = 0.05) and between residents and trained surgeons (P = 0.003) for the average completion time in Group III. There was a significant difference between students and trained surgeons (P = 0.003) for the number of contacts per average time and between students and residents (P = 0.05). There was a significant inverse correlation between stereopsis vision score and completion time in Group I and number of contacts per average time (P = 0.0004 and P = 0.01, respectively).

CONCLUSIONS

This study demonstrates potential applications of a vitreoretinal surgical simulator as a training and skills assessment tool for novice, inexperienced, and trained surgeons. A simulator can be used to teach specific techniques and train surgeons.

Computed tomographic virtual cardioscopy in a case of left atrial myxoma

Computed tomographic virtual cardioscopy was used to provide clear and precise visualisation of a myxoma with a stalk arising from the interatrial septum. This technique permits the safe, reliable, and non-invasive diagnosis of intracardiac lesions. This case is presented to assist the cardiovascular surgeon in preoperative planning or in developing a simulation of robotic cardiac surgery.

Objective psychomotor skills assessment of experienced and novice flexible endoscopists with a virtual reality simulator

The objective of this study was to determine whether the GI Mentor II virtual reality simulator can distinguish the psychomotor skills of intermediately experienced endoscopists from those of novices, and do so with a high level of consistency and reliability. A total of five intermediate and nine novice endoscopists were evaluated using the EndoBubble abstract psychomotor task. Each subject performed three repetitions of the task. Performance and error data were recorded for each trial. The intermediate group performed better than the novice group in each trial. The differences were significant in trial 1 for balloons popped (P=.001), completion time (P=.04), and errors (P=.03). Trial 2 showed significance only for balloons popped (P=.002). Trial 3 showed significance for balloons popped (P=.004) and errors (P=.008). The novice group showed significant improvement between trials 1 and 3 (P<0.05). No improvement was noted in the intermediate group. Measures of consistency and reliability were greater than 0.8 in both groups with the exception of novice completion time where test-retest reliability was 0.74. The GI Mentor II simulator can distinguish between novice and intermediate endoscopists. The simulator assesses skills with levels of consistency and reliability required for high-stakes assessment.