Task sequencing effects for open and closed loop laparoscopic skills.

The present study examined laparoscopic skill acquisition on a simulator for different sequences of open and closed loop tasks. Sixteen medical students were divided into four groups distinguished by their initial training task and subsequent transfer task. Group 1 practiced instrument navigation, an open loop task, and then transferred to grasping, a closed loop task. Group 2 practiced grasping, and then transferred to the instrument navigation task. Group 3 practiced instrument navigation and then transferred to a complex cutting task that involved both open and closed loop components. Group 4 practiced grasping and then transferred to the cutting task. The results showed distinct task sequencing effects in favor of initial practice on a closed loop task. Specifically, task completion times declined significantly when participants practiced the closed loop task followed by the open loop task. The benefits of initial practice on a closed loop task, however, were limited primarily to accuracy measures when participants transferred to the complex cutting task. The findings indicate that task order is important and that training on one task can either facilitate or impede skill acquisition on a subsequent task and that these differences reflect fundamental psychomotor characteristics of the tasks.

Comparison of a virtual reality simulator and simulated limbs for phlebotomy training.

The current study compared the CathSim virtual reality simulator with simulated limbs for phlebotomy training. In the first experiment, medical students completed two 1-hour training sessions using 1 of the 2 methods. Afterward, the students' performance was assessed with both simulated limbs and genuine patients. The results showed that students trained with the simulated limbs achieved higher scores on both the posttest and the field test with actual patients than those trained on the CathSim system. In the second study, graduate students practiced with the CathSim system for 5 hours. The results showed a significant improvement in scores from pretest to posttest for these students. However, even after extended practice, their final scores did not differ from those of the medical students in the first experiment. Critical differences in design characteristics between the 2 systems may explain these findings. Although the authors observed a clear advantage for simulated limbs over the CathSim system, neither system faithfully represents all of steps needed to perform the procedure. Thus, training decisions may require that the unique advantages afforded by each system be considered.

The efficacy of a medical virtual reality simulator for training phlebotomy.

OBJECTIVE: The present study compared the effectiveness of a virtual reality (VR) simulator for training phlebotomy with that of a more traditional approach using simulated limbs. BACKGROUND: Phlebotomy, or drawing blood, is one of the most common medical procedures; yet, there are no universal standards for training and assessing performance. The absence of any standards can lead to injuries and inaccurate test results if the procedure is improperly performed. METHOD: Twenty 3rd-year medical students were trained under one of the two methods and had their performance assessed with a 28-item checklist. RESULTS: The results showed that performance improvements were limited to those who trained with the simulated limbs, and a detailed comparison of the two systems revealed several functional and physical differences that may explain these findings. CONCLUSION: Participants trained with simulated limbs performed better than those trained with a VR simulator; however, the metrics recorded by the VR system may address some aspects of performance that could eventually prove beneficial. APPLICATION: The present study highlights the potential for medical simulators to improve patient safety by enabling trainees to practice procedures on devices instead of patients. Applications of this research include training, performance assessment, and design of simulator systems.

A simulation-based training system for surgical wound debridement.

A simulation-based training system for surgical wound debridement was developed and comprises a multimedia introduction, a surgical simulator (tutorial component), and an assessment component. The simulator includes two PCs, a haptic device, and mirrored display. Debridement is performed on a virtual leg model with a shallow laceration wound superimposed. Trainees are instructed to remove debris with forceps, scrub with a brush, and rinse with saline solution to maintain sterility. Research and development issues currently under investigation include tissue deformation models using mass-spring system and finite element methods; tissue cutting using a high-resolution volumetric mesh and dynamic topology; and accurate collision detection, cutting, and soft-body haptic rendering for two devices within the same haptic space.

Assessing surgical skill training under hazardous conditions in a virtual environment.

The present study examined the performance of a surgical procedure under simulated combat conditions. Eleven residents performed a cricothyroidotomy on a mannequin-based simulator in a fully immersive virtual environment running a combat simulation with a virtual sniper under both day and night time lighting conditions. The results showed that completion times improved between the first and second attempt and that differences between day and night time conditions were minimal. However, three participants were killed by the virtual sniper before completing the procedure. These results suggest that some participants' ability to allocate attention to the task and their surroundings was inappropriate even under simulated hazardous conditions. Further, this study shows that virtual environments offer the chance to study a wider variety of medical procedures performed under an unlimited number of conditions.

A comparison of the CathSim system and simulated limbs for teaching intravenous cannulation.

The present study describes a comparison between the CathSim VR simulator and simulated limbs for training IV cannulation. Two groups of physician assistant students underwent 2 hours of training on either method. Performance was assessed before and after training with a standardized assessment form. The results showed that all students improved after training, but the degree of improvement was greater for those trained with the simulated limbs. These findings may be due to differences between the two training methods as well as the methodology adopted in the present study.