The learning curve on the Xitact LS 500 laparoscopy simulator: profiles of performance

Background: This study assesses the acquisition of skill and the learning curve associated with the performance of the clip-and-cut task on the Xitact LS 500 virtual reality (VR) simulator in laparoscopic cholecystectomy.Methods: A group of 33 residents and interns with no previous laparoscopic experience participated in the study. All participants received a 1-h familiarization tour on the simulator. Thirty participants completed a full course of 30 simulation runs over 3 days (10 runs per day). The outcome parameters were a previously validated sum-score and time to complete performance. Results: Group demographics were similar. Of the participants who completed the full study, 16.7% appeared to have such a high level of innate psychomotor abilities that they were considered proficient in the task immediately after the initial familiarization tour. Most participants (63.3%) had a moderate level of innate abilities, and their performance improved through repetitive VR training. In our study, 20% of the participants had such a low level of innate abilities that they were unable to achieve an acceptable performance in our minimal-access surgery (MAS) simulation.Conclusions: Learning curves cannot be assessed by examining the repetitive training of only one person. There seem to be four different performance profiles, reflecting the fact that some people are more adept than others to be trained by MAS procedural VR simulation. For participants receptive to training—63.3% in this study—proficiency in the task occurs after ~25 simulative runs.     

Ergonomic testing of two different types of handles via virtual reality simulation

Background Ergonomics in laparoscopic surgery is an unsolved problem. Deficiencies of the instrument handles are well-known and described in several reports and studies. Today, virtual training modules for laparoscopic surgery are available. The aim of this study was to evaluate the ability of a virtual reality (VR) simulator to determine the ergonomic properties of two different laparoscopic instrument handles. Methods Two different types of handles, a ring and an axial handle from Richard Wolf, were used to perform the short clip and cut task of the Xitact 500 LS simulator. The task was repeated every 2 days for a period of 5 weeks. After every trial the volunteers were asked structured questions about their preferences while using the two handles. Results The axial handle was superior or equal to the ring handle in all criteria. Learning curves over the entire time and day by day were similar. No differences were found for travel distances and error rates, but task times were different for both handles. The subjects preferred the axial handle at the end of the study. Conclusion It is possible to determine differences in ergonomics of handle design with a VR trainer. In this study, the Richard Wolf axial handle was superior to the ring handle.     

Performance on a Virtual Reality Angled Laparoscope Task Correlates with Spatial Ability of Trainees

The aim of the present study was to investigate whether trainees’ performance on a virtual reality angled laparoscope navigation task correlates with scores obtained on a validated conventional test of spatial ability. 56 participants of a surgery workshop performed an angled laparoscope navigation task on the Xitact LS 500 virtual reality Simulator. Performance parameters were correlated with the score of a validated paper-and-pencil test of spatial ability. Performance at the conventional spatial ability test significantly correlated with performance at the virtual reality task for overall task score (p < 0.001), task completion time (p < 0.001) and economy of movement (p = 0.035), not for endoscope travel speed (p = 0.947). In conclusion, trainees’ performance in a standardized virtual reality camera navigation task correlates with their innate spatial ability. This VR session holds potential to serve as an assessment tool for trainees.     

Can skills assessment on a virtual reality trainer predict a surgical trainee’s talent in laparoscopic surgery?

Background A number of studies have investigated several aspects of feasibility and validity of performance assessments with virtual reality surgical simulators. However, the validity of performance assessments is limited by the reliability of such measurements, and some issues of reliability still need to be addressed. This study aimed to evaluate the hypothesis that test subjects show logarithmic performance curves on repetitive trials for a component task of laparoscopic cholecystectomy on a virtual reality simulator, and that interindividual differences in performance after considerable training are significant. According to kinesiologic theory, logarithmic performance curves are expected and an individual’s learning capacity for a specific task can be extrapolated, allowing quantification of a person’s innate ability to develop task-specific skills. Methods In this study, 20 medical students at the University of Basel Medical School performed five trials of a standardized task on the LS 500 virtual reality simulator for laparoscopic surgery. Task completion time, number of errors, economy of instrument movements, and maximum speed of instrument movements were measured. Results The hypothesis was confirmed by the fact that the performance curves for some of the simulator measurements were very close to logarithmic curves, and there were significant interindividual differences in performance at the end of the repetitive trials. Conclusions Assessment of perceptual motor skills and the innate ability of an individual with no prior experience in laparoscopic surgery to develop such skills using the LS 500 VR surgical simulator is feasible and reliable.     

Validation of a new basic virtual reality simulator for training of basic endoscopic skills

BACKGROUND: The aim of this study was to establish content, face, concurrent, and the first step of construct validity of a new simulator, the SIMENDO, in order to determine its usefulness for training basic endoscopic skills. METHODS: The validation started with an explanation of the goals, content, and features of the simulator (content validity). Then, participants from eight different medical centers consisting of experts (> or =100 laparoscopic procedures performed) and surgical trainees (<100) were informed of the goals and received a "hands-on tour" of the virtual reality (VR) trainer. Subsequently, they were asked to answer 28 structured questions about the simulator (face validity). Ratings were scored on a scale from 1 (very bad/useless) to 5 (excellent/very useful). Additional comments could be given as well. Furthermore, two experiments were conducted. In experiment 1, aimed at establishing concurrent validity, the training effect of a single-handed hand-eye coordination task in the simulator was compared with a similar task in a conventional box trainer and with the performance of a control group that received no training. In experiment 2 (first step of construct validity), the total score of task time, collisions, and path length of three consecutive runs in the simulator was compared between experts (>100 endoscopic procedures) and novices (no experience). RESULTS: A total of 75 participants (36 expert surgeons and 39 surgical trainees) filled out the questionnaire. Usefulness of tasks, features, and movement realism were scored between a mean value of 3.3 for depth perception and 4.3 for appreciation of training with the instrument. There were no significant differences between the mean values of the scores given by the experts and surgical trainees. In response to statements, 81% considered this VR trainer generally useful for training endoscopic techniques to residents, and 83% agreed that the simulator was useful to train hand-eye coordination. In experiment 1, the training effect for the single-handed task showed no significant difference between the conventional trainer and the VR simulator (concurrent validity). In experiment 2, experts scored significantly better than novices on all parameters used (construct validity). CONCLUSION: Content, face, and concurrent validity of the SIMENDO is established. The simulator is considered useful for training eye-hand coordination for endoscopic surgery. The evaluated task could discriminate between the skills of experienced surgeons and novices, giving the first indication of construct validity.     

Learning rate for laparoscopic surgical skills on MIST VR, a virtual reality simulator: quality of human-computer interface

Acquiring laparoscopic surgical skills involves initial learning of cognitive and motor skills followed by refinement of those skills. The successful use of a virtual reality simulator depends on the quality of the interface for the human-computer interaction and this can be determined by the initial learning rate. MIST VR, a part-task virtual reality laparoscopic simulator, provides objective assessment of psychomotor skills and can generate an overall score for performance, based upon errors made and time taken for six different tasks. This study analysed the rate of early task/instrument/computer familiarization on consecutive scores achieved by surgically experienced and naive individuals. Eleven surgeons, 18 medical students and seven non-medical personnel were tested on the simulator up to ten consecutive times, within a 2-week period. Performance data from every task and repetition were analysed to obtain individual scores of task performance. The calculation of overall score penalized errors far more heavily than total time taken, with high scores indicating poor performance. The surgeon-computer interface generated a rapid and significant early familiarization curve up to the third session on the simulator, with significant reductions in both time taken and total contact errors made. These results suggest that MIST VR represents a high quality interface. Surgeons scored consistently and significantly better than other subjects on all tasks. For surgically naive individuals, it was possible to predict the level of laparoscopic skills performance that would be attained after overcoming initial simulator learning curve, by studying their initial score. Overall scores reflected surgical experience and suggest that the simulator is measuring surgically relevant parameters. MIST VR provides a validated and much needed method for objective assessment of laparoscopic skills, for a variety of surgical disciplines.     

Augmented versus Virtual Reality Laparoscopic Simulation: What Is the Difference?

BACKGROUND: Virtual reality (VR) is an emerging new modality for laparoscopic skills training; however, most simulators lack realistic haptic feedback. Augmented reality (AR) is a new laparoscopic simulation system offering a combination of physical objects and VR simulation. Laparoscopic instruments are used within an hybrid mannequin on tissue or objects while using video tracking. This study was designed to assess the difference in realism, haptic feedback, and didactic value between AR and VR laparoscopic simulation. METHODS: The ProMIS AR and LapSim VR simulators were used in this study. The participants performed a basic skills task and a suturing task on both simulators, after which they filled out a questionnaire about their demographics and their opinion of both simulators scored on a 5-point Likert scale. The participants were allotted to 3 groups depending on their experience: experts, intermediates and novices. Significant differences were calculated with the paired t-test. RESULTS: There was general consensus in all groups that the ProMIS AR laparoscopic simulator is more realistic than the LapSim VR laparoscopic simulator in both the basic skills task (mean 4.22 resp. 2.18, P < 0.000) as well as the suturing task (mean 4.15 resp. 1.85, P < 0.000). The ProMIS is regarded as having better haptic feedback (mean 3.92 resp. 1.92, P < 0.000) and as being more useful for training surgical residents (mean 4.51 resp. 2.94, P < 0.000). CONCLUSIONS: In comparison with the VR simulator, the AR laparoscopic simulator was regarded by all participants as a better simulator for laparoscopic skills training on all tested features.     

How to select aspirant laparoscopic surgical trainees: establishing concurrent validity comparing Xitact LS500 index performance scores with standardized psychomotor aptitude test battery scores

BACKGROUND: Although a controversial topic in medical education, the selection of aspirant surgical trainees is a subject that needs to be addressed. In the view of preventing surgical trainee drop-outs and of appropriate allocation of limited resources, it is an issue critical to the profession. Traditional methods of selection are often subjective, and do not seem to correlate with skill needed for surgery. Standardized neuropsychometric test batteries may be useful in helping to select aspirant laparoscopic surgeons. Our study attempts to link surgical novices' psychometric ability test battery data with actual performance outcome on an objective, validated, and reproducible surgical laparoscopic task using virtual-reality simulation. MATERIALS AND METHODS: Thirty-three novices with no laparoscopic surgical experience participated. Each participant performed the Xitact LS500 Virtual Reality cholecystectomy clip-and-cut module 30 times. Individual learning curves were computed and patterns were assessed. Participants were examined using the aptitude test battery including the Abstract Reasoning test, the Space Relations test, the Gibson Spiral Maze test, and the Crawford Small Parts Dexterity tester. RESULTS: Over 900 virtual-reality simulation tasks were generated and assessed. Of the participants, 93.3% were able to complete the virtual-reality simulation 30 times and all elements of our aptitude test battery. The abstract reasoning test is the only test correlating significantly to Xitact test outcome. This test is highly correlated to the space relations test. Both tests have discriminative power, comparing groups of performers. CONCLUSIONS: The present study addresses the concurrent validity in aptitude testing, comparing scores of surgical novices on the Xitact LS500 laparoscopic cholecystectomy virtual-reality simulation with performance scores on a battery of standardized psychometric aptitude tests. The abstract reasoning and the space-relation test have predictive and selective value, identifying individuals who have good laparoscopic surgical virtual-reality performance. Aspiring laparoscopic surgeons who score below 25 on either test, that is, an expected 36%, would have to be further assessed using Xitact surgical task performance. The group of participants scoring above 35 on the Abstract Reasoning test and above 45 on the Space Relations test, that is, an expected 18% of the population, is unlikely to mal-perform on Xitact. The other 46% could very well benefit from Xitact simulation and assessment when the opportunity is present.     

Virtual reality training leads to faster adaptation to the novel psychomotor restrictions encountered by laparoscopic surgeons

BACKGROUND: The fulcrum effect of the body wall on instrument handling poses a major obstacle to the mastery of instrument coordination for junior laparoscopic surgeons. This study evaluated three types of laparoscopic simulator training to assess their ability to promote the user's adaptation to the fulcrum effect. METHODS: Thirty-two participants with no previous experience in laparoscopic surgery were randomly assigned to one of four groups representing different training conditions. One group was assigned to use a virtual reality simulator (MIST VR); two others were given a laparoscopic Z or U maze-tracking task. The control group received no training. Subjects were asked to perform a 2-min laparoscopic cutting task under normal laparoscopic imaging conditions first before and then after training. RESULTS: In the test trial, subjects who trained on MIST VR made significantly more correct incisions (p < 0.0001) and fewer incorrect incisions (p < 0.0001). CONCLUSION: Training on a virtual reality simulator such as MIST VR helps laparoscopic novices adapt to the fulcrum effect faster.     

Face-, expert,and referent validity of the Xitact LS500 laparoscopy simulator

Background: This study was undertaken to establish face-, expert, and referent validity of the Xitact LS500; a virtual reality laparoscopic cholecystectomy simulator. Methods: A four-page, 20-item structured questionnaire was presented to 120 surgeons attending a surgical convention. Participants received an instructed hands-on "tour" on the Xitact simulator. Data were analyzed according to the level of experience of the surgeon, resulting in an "expert group opinion" of 87 surgeons and a "referent group opinion" of 33 surgeons. Results: The majority of respondents believe Xitact has the potential to become a useful tool in teaching (93.1%) and measuring performance assessment (79.3%) in laparoscopic cholecystectomy. Expert- and referent-group opinion does not differ significantly on any of the presented statements. The opinion regarding the realism of the virtual laparoscopic cholecystectomy environment is favorable among both groups, although it is considered not yet perfect. The "haptic feedback" sensation of the Xitact is a parameter that needs further development. Conclusions: Both expert- and referent surgeons value Xitact to be an important and useful tool in the laparoscopic teaching setting. Further studies need to be performed to establish the construct validity of the simulator (e.g., to what extent is the simulator logically encompassed into a theoretical framework of acquiring skills, needed for the laparoscopic cholecystectomy) to measure shortening of learning curves on the laparoscopic cholecystectomy procedure, and ultimately to justify its use in the surgical curriculum.     

Validated robotic laparoscopic surgical training in a virtual-reality environment

Background  A robotic virtual-reality (VR) simulator has been developed to improve robot-assisted training for laparoscopic surgery and to enhance surgical performance in laparoscopic skills. The simulated VR training environment provides an effective approach to evaluate and improve surgical performance. This study presents our findings of the VR training environment for robotic laparoscopy. Methods  Eight volunteers performed two inanimate tasks in both the VR and the actual training environment. The tasks were bimanual carrying (BC) and needle passing (NP). For the BC task, the volunteers simultaneously transferred two plastic pieces in opposite directions five times consecutively. The same volunteers passed a surgical needle through six pairs of holes in the NP task. Both tasks require significant bimanual coordination that mimics actual laparoscopic skills. Data analysis included time to task completion, speed and distance traveled of the instrument tip, as well as range of motion of the subject’s wrist and elbow of the right arm. Electromyography of the right wrist flexor and extensor were also analyzed. Paired t-tests and Pearson’s r were used to explore the differences and correlations between the two environments. Results  There were no significant differences between the actual and the simulated VR environment with respect to the BC task, while there were significant differences in almost all dependent parameters for the NP task. Moderate to high correlations for most dependent parameters were revealed for both tasks. Conclusions  Our data shows that the VR environment adequately simulated the BC task. The significant differences found for the NP task may be attributed to an oversimplification in the VR environment. However, they do point to the need for improvements in the complexity of our VR simulation. Further research work is needed to develop effective and reliable VR environments for robotic laparoscopic training.     

The importance of haptic feedback in laparoscopic suturing training and the additive value of virtual reality simulation

Introduction Previous studies on the difference between physical, augmented and virtual reality (VR) simulation state that haptic feedback is an important feature in laparoscopic suturing simulation. Objective assessment is important to improve skills during training. This study focuses on the additive value of VR simulation for laparoscopic suturing training. Methods All participants of several European Association for Endoscopic Surgery (EAES)-approved laparoscopic skills courses (N = 45) filled out a questionnaire on their opinion on laparoscopic suturing training. Additionally, participants with little or no laparoscopic suturing experience were allotted to two groups: group A (N = 10), who started training on the box trainer and subsequently the VR simulator (SimSurgery), and group B (N = 10), who began on the VR simulator followed by the box. Finally, suturing and knot-tying skills were assessed by an expert observer, using a standard evaluation form (eight items on five-point-Likert scale). The same was done after the initial training on the box in group A, as a control. Significant differences were calculated with the independent-sample t-test and the paired t-test. Results The total score of group A was higher than both group B and control (means of 30.80, 27.60, 28.20, respectively), but not significantly. The only tendency to a significant difference between group A and B was found in ‘taking proper bites’ (mean 4.10 versus 3.60, p = 0.054). All the participants scored the features of the box trainer significantly higher than those of the VR simulator (p < 0.001), 46.7% was of the opinion that the box alone would be sufficient for laparoscopic suturing training. Conclusion From this study we can conclude that VR simulation does not have a significant additional value in laparoscopic suturing training, over traditional box trainers. One should consider that the future development in VR simulation should focus on basic skills and component tasks of procedural training in laparoscopic surgery, rather than laparoscopic suturing.     

Short-duration virtual reality simulation training positively impacts performance during laparoscopic colectomy in animal model: results of a single-blinded randomized trial

Background

Several studies have demonstrated skills transfer after virtual reality (VR) simulation training in laparoscopic surgery. However, the impact of VR simulation training on transfer of skills related to laparoscopic colectomy remains not investigated. The present study aimed at determining the impact of VR simulation warm-up on performance during laparoscopic colectomy in the porcine model.

Methods

Fourteen residents naive to laparoscopic colectomy as surgeons were randomly assigned in block to two groups. Seven trainees completed a 2-h VR simulator training in the laparoscopic sigmoid colectomy module (study group). The remaining seven surgeons (control group) underwent no intervention. On the same day, all participants performed a sigmoid colectomy with anastomosis on a pig. All operations were video recorded. Two board-certified expert colorectal surgeons independently assessed performance during the colectomy on the swine. Examiners were blinded to group assignment. The two examiners used a previously validated clinical instrument specific to laparoscopic colectomy. The primary outcome was the generic and specific skills score values.

Results

Surgeons undergoing short-duration training on the VR simulator performed significantly better during laparoscopic colectomy on the pig regarding general and specific technical skills evaluation. The average score of generic skills was 17.2 (16.5–18) for the control group and 20.1 (16.5–22) for the study group (p = 0.002). The specific skills average score for the control group was 20.2 (19–21.5) and 24.2 (21–27.5) for the study group (p = 0.001). There was acceptable concordance (Kendall’s W) regarding the video assessment of generic (W = 0.78) and specific skills (W = 0.84) between the two examiners.

Conclusions

A single short-duration VR simulator practice positively impacted surgeons’ generic and specific skills performance required to accomplish laparoscopic colectomy in the swine model.     

Proficiency training on a virtual reality robotic surgical skills curriculum

Introduction

The clinical application of robotic surgery is increasing. The skills necessary to perform robotic surgery are unique from those required in open and laparoscopic surgery. A validated laparoscopic surgical skills curriculum (Fundamentals of Laparoscopic Surgery or FLS?) has transformed the way surgeons acquire laparoscopic skills. There is a need for a similar skills training and assessment tool for robotic surgery. Our research group previously developed and validated a robotic training curriculum in a virtual reality (VR) simulator. We hypothesized that novice robotic surgeons could achieve proficiency levels defined by more experienced robotic surgeons on the VR robotic curriculum, and that this would result in improved performance on the actual daVinci Surgical System?.

Methods

25 medical students with no prior robotic surgery experience were recruited. Prior to VR training, subjects performed 2 FLS tasks 3 times each (Peg Transfer, Intracorporeal Knot Tying) using the daVinci Surgical System? docked to a video trainer box. Task performance for the FLS tasks was scored objectively. Subjects then practiced on the VR simulator (daVinci Skills Simulator) until proficiency levels on all 5 tasks were achieved before completing a post-training assessment of the 2 FLS tasks on the daVinci Surgical System? in the video trainer box.

Results

All subjects to complete the study (1 dropped out) reached proficiency levels on all VR tasks in an average of 71 (± 21.7) attempts, accumulating 164.3 (± 55.7) minutes of console training time. There was a significant improvement in performance on the robotic FLS tasks following completion of the VR training curriculum.

Conclusions

Novice robotic surgeons are able to attain proficiency levels on a VR simulator. This leads to improved performance in the daVinci surgical platform on simulated tasks. Training to proficiency on a VR robotic surgery simulator is an efficient and viable method for acquiring robotic surgical skills.     

Randomized clinical trial of virtual reality simulation for laparoscopic skills training

BACKGROUND: This study examined the impact of virtual reality (VR) surgical simulation on improvement of psychomotor skills relevant to the performance of laparoscopic cholecystectomy. METHODS: Sixteen surgical trainees performed a laparoscopic cholecystectomy on patients in the operating room (OR). The participants were then randomized to receive VR training (ten repetitions of all six tasks on the Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR)) or no training. Subsequently, all subjects performed a further laparoscopic cholecystectomy in the OR. Both operative procedures were recorded on videotape, and assessed by two independent and blinded observers using predefined objective criteria. Time to complete the procedure, error score and economy of movement score were assessed during the laparoscopic procedure in the OR. RESULTS: No differences in baseline variables were found between the two groups. Surgeons who received VR training performed laparoscopic cholecystectomy significantly faster than the control group (P=0.021). Furthermore, those who had VR training showed significantly greater improvement in error (P=0.003) and economy of movement (P=0.003) scores. CONCLUSION: Surgeons who received VR simulator training showed significantly greater improvement in performance in the OR than those in the control group. VR surgical simulation is therefore a valid tool for training of laparoscopic psychomotor skills and could be incorporated into surgical training programmes.     

Virtual reality laparoscopic skill assessment in microgravity

BACKGROUND: The objective of the study was to assess if performance of basic laparoscopic skills on a virtual reality (VR) simulator is impaired in microgravity relative to normal gravitational influences. MATERIALS AND METHODS: Fourteen subjects with various educational backgrounds underwent basic laparoscopy skill training for five consecutive days on the ground before flying aboard NASA's KC-135 zero-gravity laboratory. The participants performed basic laparoscopic exercises (clip applying, grasping, cutting, and suturing) on a VR laparoscopy simulator, both on the ground and during 25-s microgravity windows in parabolic flight. Skill levels after ground training were compared with skill levels in performing the same tasks in microgravity. Blinded reviewers measured the number of tasks successfully completed, tissue damage number, left and right hand path lengths during task execution, and percentage of task attempts that resulted in successful completion. RESULTS: A significant increase in tissue injury (t test, P < 0.05) and task erosion were seen in clip applying, cutting, and grasping in microgravity (45%, 20% and 57% decrease in task attempts that resulted in a successful completion, respectively). However, there was no significant difference in the left and right hand path lengths, and the total number of tasks successfully completed on the ground versus in microgravity, for any of the four laparoscopic exercises (t test, P > 0.05). CONCLUSION: This study demonstrates decreased efficiency and increased injury to the simulated tissues in performing laparoscopic skills during microgravity as compared to performing these skills in standard gravitational influence. Additional experiments are indicated to further develop and validate VR microgravity surgical simulation.     

Incorporation of proficiency criteria for basic laparoscopic skills training: how does it work?

Background  It is desirable that surgical trainees are proficient in basic laparoscopic motor skills (eye–hand coordination). The present study evaluated the use of predefined proficiency criteria on a basic virtual reality (VR) simulator in preparation for a laparoscopic course on animal models. Methods  Twenty-eight surgical trainees who enrolled for a basic laparoscopic course were trained on a basic (VR) simulator until their performance met predefined criteria. Two different criteria were defined, based on the performance of experienced laparoscopic surgeons on the simulator. In the first group (n = 10), the criteria were set at the 75th percentile of the laparoscopic surgeons’ performance on the simulator and in the second group, at the 50th percentile (n = 18). Training time and number of attempts needed until the performance criteria were met were measured. Results  In the first group, training time needed to pass the test ranged from 29 to 77 min (median: 63 min) with a range of 43–90 attempts (median 61 attempts). In the second group, training time ranged from 38 to 180 min (median 80 min) with a range of 55–233 attempts (median 95 attempts). Experience with assisting or performing laparoscopic procedures varied widely and was not correlated with the training time and number of attempts needed to pass the criteria. Conclusions  The performance criteria for training laparoscopic motor skills on a (VR) simulator resulted in wide variation between surgical trainees in time and number of attempts needed to pass the criteria. This demands training courses with a flexible time span tailored to the individual level of the trainee.     

A prospective randomized study to test the transfer of basic psychomotor skills from virtual reality to physical reality in a comparable training setting

OBJECTIVE: To test whether basic skills acquired on a virtual endoscopic surgery simulator are transferable from virtual reality to physical reality in a comparable training setting. SUMMARY BACKGROUND DATA: For surgical training in laparoscopic surgery, new training methods have to be developed that allow surgeons to first practice in a simulated setting before operating on real patients. A virtual endoscopic surgery trainer (VEST) has been developed within the framework of a joint project. Because of principal limitations of simulation techniques, it is essential to know whether training with this simulator is comparable to conventional training. METHODS: Devices used were the VEST system and a conventional video trainer (CVT). Two basic training tasks were constructed identically (a) as virtual tasks and (b) as mechanical models for the CVT. Test persons were divided into 2 groups each consisting of 12 novices and 4 experts. Each group carried out a defined training program over the course of 4 consecutive days on the VEST or the CVT, respectively. To test the transfer of skills, the groups switched devices on the 5th day. The main parameter was task completion time. RESULTS: The novices in both groups showed similar learning curves. The mean task completion times decreased significantly over the 4 training days of the study. The task completion times for the control task on Day 5 were significantly lower than on Days 1 and 2. The experts' task completion times were much lower than those of the novices. CONCLUSIONS: This study showed that training with a computer simulator, just as with the CVT, resulted in a reproducible training effect. The control task showed that skills learned in virtual reality are transferable to the physical reality of a CVT. The fact that the experts showed little improvement demonstrates that the simulation trains surgeons in basic laparoscopic skills learned in years of practice.     

A comparison between randomly alternating imaging, normal laparoscopic imaging, and virtual reality training in laparoscopic psychomotor skill acquisition

OBJECTIVES: To evaluate virtual reality as a laparoscopic training device in helping surgeons to automate to the "fulcrum effect" by comparing it to time-matched training programs using randomly alternating images (ie, y-axis inverted and normal laparoscopic) and normal laparoscopic viewing conditions. METHODS: Twenty-four participants (16 females and 8 males), were randomly assigned to minimally invasive surgery virtual reality (MIST VR), randomly alternating (between y-axis inverted and normal laparoscopic images), and normal laparoscopic imaging condition. Participants were requested to perform a 2-minute laparoscopic cutting task before and after training. RESULTS: In the test trial participants who trained on the MIST VR performed significantly better than those in the normal laparoscopic and randomly alternating imaging conditions. CONCLUSION: The results show that virtual reality training may provide faster skill acquisition with particular reference to automation of the fulcrum effect. MIST VR provides a new way of training laparoscopic psychomotor surgical skills.     

Virtual ureteroscopy predicts ureteroscopic proficiency of medical students on a cadaver

PURPOSE: Training on a virtual reality (VR) simulator has been shown to improve the performance of VR endoscopic tasks by novice endoscopists. However, to our knowledge the translation of VR skills into clinical endoscopic proficiency has not been demonstrated. We established criterion validity for a VR ureteroscopy simulator by evaluating VR trained subjects in a cadaver model. MATERIALS AND METHODS: A total of 32 participants, including 16 medical students and 16 urology residents, were evaluated at baseline on a VR ureteroscopy simulator (Uromentor, Simbionix, Lod, Israel), performing simple diagnostic ureteroscopy. The students then underwent 5 hours of supervised training on the simulator. Two weeks later all participants were reevaluated (VR2) on the simulator when repeating the initial task. Each participant was then assessed on the performance of a similar diagnostic ureteroscopy in a male cadaver. RESULTS: In medical students VR2 and cadaver performances correlated closely for several measured parameters (total time for task completion and overall global ratings score). In contrast, there was little correlation between the 2 performances in residents. Indeed, performance on the cadaver correlated more closely with the training level than VR2 scores. Despite VR training medical students were unable to perform cadaver ureteroscopy comparably to residents. CONCLUSIONS: For novice endoscopists performance on the simulator after training predicted operative (cadaver) performance and, thus, it may be useful for the education and assessment of physicians in training. However, VR training is unable to override the impact of clinical training, although it may help shorten the learning curve early in training.