Richard M. Satava

Virtual Reality Training Improves Operating Room Performance: Results of a Randomized, Double-Blinded Study

ObjectiveTo demonstrate that virtual reality (VR) training transfers technical skills to the operating room (OR) environment. Summary Background DataThe use of VR surgical simulation to train skills and reduce error risk in the OR has never been demonstrated in a prospective, randomized, blinded study. MethodsSixteen surgical residents (PGY 1–4) had baseline psychomotor abilities assessed, then were randomized to either VR training (MIST VR simulator diathermy task) until expert criterion levels established by experienced laparoscopists were achieved (n = 8), or control non-VR-trained (n = 8). All subjects performed laparoscopic cholecystectomy with an attending surgeon blinded to training status. Videotapes of gallbladder dissection were reviewed independently by two investigators blinded to subject identity and training, and scored for eight predefined errors for each procedure minute (interrater reliability of error assessment r > 0.80). ResultsNo differences in baseline assessments were found between groups. Gallbladder dissection was 29% faster for VR-trained residents. Non-VR-trained residents were nine times more likely to transiently fail to make progress (P < .007, Mann-Whitney test) and five times more likely to injure the gallbladder or burn nontarget tissue (chi-square = 4.27, P < .04). Mean errors were six times less likely to occur in the VR-trained group (1.19 vs. 7.38 errors per case;P < .008, Mann-Whitney test). ConclusionsThe use of VR surgical simulation to reach specific target criteria significantly improved the OR performance of residents during laparoscopic cholecystectomy. This validation of transfer of training skills from VR to OR sets the stage for more sophisticated uses of VR in assessment, training, error reduction, and certification of surgeons.

Virtual reality simulation for the operating room: proficiency-based training as a paradigm shift in surgical skills training.

Summary Background Data:To inform surgeons about the practical issues to be considered for successful integration of virtual reality simulation into a surgical training program. The learning and practice of minimally invasive surgery (MIS) makes unique demands on surgical training programs. A decade ago Satava proposed virtual reality (VR) surgical simulation as a solution for this problem. Only recently have robust scientific studies supported that vision Methods:A review of the surgical education, human-factor, and psychology literature to identify important factors which will impinge on the successful integration of VR training into a surgical training program. Results:VR is more likely to be successful if it is systematically integrated into a well-thought-out education and training program which objectively assesses technical skills improvement proximate to the learning experience. Validated performance metrics should be relevant to the surgical task being trained but in general will require trainees to reach an objectively determined proficiency criterion, based on tightly defined metrics and perform at this level consistently. VR training is more likely to be successful if the training schedule takes place on an interval basis rather than massed into a short period of extensive practice. High-fidelity VR simulations will confer the greatest skills transfer to the in vivo surgical situation, but less expensive VR trainers will also lead to considerably improved skills generalizations. Conclusions:VR for improved performance of MIS is now a reality. However, VR is only a training tool that must be thoughtfully introduced into a surgical training curriculum for it to successfully improve surgical technical skills.

Surgical robotics: the early chronicles: a personal historical perspective.

The use of robotics has been emerging for approximately 75 years, but only during the past 5 years has the potential of robotics been recognized by the surgical community as a whole. This personal perspective chronicles the development of robotics for the general surgical community, the role of the military medical research effort, and many of the major programs that contributed to the current success of robotics.

Virtual reality surgical simulator

SummaryThe virtual-reality surgical simulator signals the beginning of an era of computer simulation for surgery. The surgical resident of the future will learn new perspectives on surgical anatomy and repeatedly practice surgical procedures until they are perfect before performing surgery on patients. Primitive though these initial steps are, they represent the foundation for an educational base that will be as important to surgery as the flight simulator is to aviation. It is anticipated that the full development of the surgical simulator will take less than the 40 years which was required for flight simulators to become an indispensable ingredient of pilot training. As the system evolves, many new and yet-to-be-imagined applications will arise, but we must have understanding and patience as we wait for computer power to improve to a point where VR surgical simulation can emerge from its PacMan era.

Fundamental principles of validation, and reliability: rigorous science for the assessment of surgical education and training

Surgery has always been a dynamic discipline. It has a long history of groundbreaking innovations that dramatically improved the way patients were treated and surgery was practiced. However, nothing could have prepared the surgical community for the revolutionary advances of the last 2 decades. Almost overnight, the traditional open approach to surgery was replaced by a minimally invasive surgery (MIS) approach [2]. Practitioners quickly realized that this novel approach would require new types of training. Suddenly, the directors of surgical residency programs had to deal with faculty members who were questioning the training paradigm that had served surgery well for a century. The traditional Halsteadian method did not seem to be suitable for the new types of skills required for MIS. To make matters worse, the length of time allocated to training residents was contracting. In the European Union in 2001 the European Working time Directive was extended to include physicians in training and this year in the United States of America the mandatory 80 hour work week restriction has been instituted, both dramatically reducing work/training hours for residents. At the same time, the practice of surgery came under scrutiny in another, apparently unrelated area when the value and relevance of surgical research became an issue of controversy. In an unprecedented attack, the editor of the Lancet [6] publically called into question the quality of current surgical research. In an editorial entitled ‘‘Surgical Research or Comic Opera?’’ Dr. Horton expressed grave reservations about its utility, validity, and usefulness. Although the editorial was met by the surgical community with the predictable indignant response, Horton did make some valid points. Not necessarily in response to this editorial but certainly contiguous to it, surgical research appears to be moving away from reliance on retrospective data to prospective, randomized, and—where possible— blinded data. It is our contention that these two issues, i.e., MIS skills and surgical research, have now converged around the very essence of our surgical heritage—the stringent use of the ‘‘scientific method’’ and objective assessment. Perhaps this is best exemplified by the relatively new editorial practice of prioritizing prospective, randomized, blinded surgical trials for publication. Although blinded, randomized, controlled trial design can be employed to answer definitively many surgical research questions, we must remember that this design is only one of a quiver full of research methodologies, and may not always be the experimental design of choice. The function of good science is to show clear cause-and-effect relationships, and this does not always require a prospective, randomized, double-blind experimental design. Indeed the optimal method may not even be experimental, but statistical, such as Structural Equation Models [3]. This methodology will almost certainly be required to answer the question of which fundamental psychological abilities predict MIS skills/performance or what factors predict obesity or treatment outcomes in obesity. In both of these examples the answer will be multifactorial, which precludes the use of traditional experimental design. The control exerted with traditional experimental design will be replaced with the equally powerful (but methodologically more sophisticated) ‘‘statistical’’ control. The point we want to make here is that there is no ‘‘magic bullet’’ experimental methodology for surgical research; instead, there is a range of experimental designs that should be applied appropriately to answer the pertinent research question. Research design should therefore vary depending on the circumstances. An eloquent example can be found in a report form the Dundee MIS group, who used four subjects and, in essence, a single-subject design to evaluate the utility of three-dimensional camera systems [5]. The research design they used answered the question unequivocally, but Correspondence to: A. G. Gallagher Surg Endosc (2003) 17: 1525–1529 DOI: 10.1007/s00464-003-0035-4

Virtual reality as a metric for the assessment of laparoscopic psychomotor skills. Learning curves and reliability measures.

Background: The objective assessment of the psychomotor skills of surgeons is now a priority; however, this is a difficult task because of measurement difficulties associated with the assessment of surgery in vivo. In this study, virtual reality (VR) was used to overcome these problems. Methods: Twelve experienced (>50 minimal-access procedures), 12 inexperienced laparoscopic surgeons (<10 minimal-access procedures), and 12 laparoscopic novices participated in the study. Each subject completed 10 trials on the Minimally Invasive Surgical Trainer; Virtual Reality (MIST VR). Results: Experienced laparoscopic surgeons performed the tasks significantly (p < 0.01) faster, with less error, more economy in the movement of instruments and the use of diathermy, and with greater consistency in performance. The standardized coefficient alpha for performance measures ranged from a = 0.89 to 0.98, showing high internal measurement consistency. Test–retest reliability ranged from r = 0.96 to r = 0.5. Conclusion: VR is a useful tool for evaluating the psychomotor skills needed to perform laparoscopic surgery.

A consensus document on robotic surgery

“Robotic surgery” originated as an imprecise term, but it has been widely used by both the medical and lay press and is now generally accepted by the medical community. The term refers to surgical technology that places a computer-assisted electromechanical device in the path between the surgeon and the patient. A more scientifically accurate term for current devices would be “remote telepresence manipulators” because available technology does not generally function without the explicit and direct control of a human operator. For the purposes of the document, we define robotic surgery as a surgical procedure or technology that adds a computer technology–enhanced device to the interaction between a surgeon and a patient during a surgical operation and assumes some degree of control heretofore completely reserved for the surgeon. For example, in laparoscopic surgery, the surgeon directly controls and manipulates tissue, albeit at some distance from the patient and through a fulcrum point in the abdominal wall. This differs from the use of current robotic devices, whereby the surgeon sits at a console, typically in the operating room but outside the sterile field, directing and controlling the movements of one or more robotic arms. Although the surgeon still maintains control over the operation, the control is indirect and effected from an increased distance. This definition of robotic surgery encompasses micromanipulators, remotely controlled endoscopes, and console-manipulator devices. The key elements are enhancements of the surgeon’s abilities—be they vision, tissue manipulation, or tissue sensing—and alteration of the traditional direct local contact between surgeon and patient.

Discriminative validity of the Minimally Invasive Surgical Trainer in Virtual Reality (MIST-VR) using criteria levels based on expert performance

Background: Increasing constraints on the time and resources needed to train surgeons have led to a new emphasis on finding innovative ways to teach surgical skills outside the operating room. Virtual reality training has been proposed as a method to both instruct surgical students and evaluate the psychomotor components of minimally invasive surgery ex vivo. Methods: The performance of 100 laparoscopic novices was compared to that of 12 experienced (>50 minimally invasive procedures) and 12 inexperienced (<10 minimally invasive procedures) laparoscopic surgeons. The values of the experienced surgeons’ performance were used as benchmark comparators (or criterion measures). Each subject completed six tasks on the Minimally Invasive Surgical Trainer—Virtual Reality (MIST-VR) three times. The outcome measures were time to complete the task, number of errors, economy of instrument movement, and economy of diathermy. Results: After three trials, the mean performance of the medical students approached that of the experienced surgeons. However, 7–27% of the scores of the students fell more than two SD below the mean scores of the experienced surgeons (the criterion level). Conclusions: The MIST-VR system is capable of evaluating the psychomotor skills necessary in laparoscopic surgery and discriminating between experts and novices. Furthermore, although some novices improved their skills quickly, a subset had difficulty acquiring the psychomotor skills. The MIST-VR may be useful in identifying that subset of novices.

Accomplishments and challenges of surgical simulation.

For nearly a decade, advanced computer technologies have created extraordinary educational tools using three-dimensional (3D) visualization and virtual reality. Pioneering efforts in surgical simulation with these tools have resulted in a first generation of simulators for surgical technical skills. Accomplishments include simulations with 3D models of anatomy for practice of surgical tasks, initial assessment of student performance in technical skills, and awareness by professional societies of potential in surgical education and certification. However, enormous challenges remain, which include improvement of technical fidelity, standardization of accurate metrics for performance evaluation, integration of simulators into a robust educational curriculum, stringent evaluation of simulators for effectiveness and value added to surgical training, determination of simulation application to certification of surgical technical skills, and a business model to implement and disseminate simulation successfully throughout the medical education community. This review looks at the historical progress of surgical simulators, their accomplishments, and the challenges that remain.

Evaluation of structured and quantitative training methods for teaching intracorporeal knot tying

Background: We evaluated the effectiveness of five training methods-four structured and one unstructured-for teaching intracorporeal knot tying. Methods: Forty-three graduate students without prior laparoscopic experience were randomly assigned to one of five training groups, and their performance in 10 intracorporeal knot tying trials was evaluated, using time to complete a knot as the outcome measure. Results: The average knot tying times for the four structured groups were significantly faster than the unstructured group (p < 0.0001). AMONG THE FOUR STRUCTURED GROUPS, THE MINIMALLY INVASIVE SURGICAL TRAINER-VIRTUAL REALITY (MIST-VR) AND THE BOX TRAINER DRILLS SHOWED THE MOST RAPID IMPROVEMENTS. THE MIST-VR IMPROVED AVERAGE SUTURING TIME FROM TRIAL ONE TO TRIAL TWO (P = 0.05), THE BOX TRAINER DRILLS GROUP IMPROVED FROM TRIAL ONE TO TRIAL FOUR (P = 0.01), AND THE OTHER TWO GROUPS SHOWED SLOWER IMPROVEMENTS. STATISTICALLY SIGNIFICANT CORRELATIONS WERE OBSERVED BETWEEN SCORES ON MIST-VR TASKS AND AVERAGE KNOT TYING TIMES (R > 0.7, p < 0.05). Conclusion: Structured training can be useful for the development of laparoscopic skills. MIST-VR is a valuable part of this training, particularly in the objective evaluation of performance.