The Role of Haptic Feedback in Laparoscopic Simulation Training

Introduction

Laparoscopic virtual reality simulators are becoming a ubiquitous tool in resident training and assessment. These devices provide the operator with various levels of realism, including haptic (or force) feedback. However, this feature adds significantly to the cost of the devices, and limited data exist assessing the value of haptics in skill acquisition and development. Utilizing the Laparoscopy VR (Immersion Medical, Gaithersburg, MD), we hypothesized that the incorporation of force feedback in the simulated operative environment would allow superior trainee performance compared with performance of the same basic skills tasks in a non-haptic model.

Methods

Ten medical students with minimal laparoscopic experience and similar baseline skill levels as proven by performance of two fundamentals of laparoscopic surgery (FLS) tasks (peg transfer and cutting drills) voluntarily participated in the study. Each performed two tasks, analogous to the FLS drills, on the Laparoscopy VR at 3 levels of difficulty, based on the established settings of the manufacturer. After achieving familiarity with the device and tasks, the students completed the drills both with and without force feedback. Data on completion time, instrument path length, right and left hand errors, and grasping tension were analyzed. The scores in the haptic-enhanced simulation environment were compared with the scores in the non-haptic model and analyzed utilizing Student's t-test.

Results

The peg transfer drill showed no difference in performance between the haptic and non-haptic simulations for all metrics at all three levels of difficulty. For the more complex cutting exercise, the time to complete the tasks was significantly shorter when force feedback was provided, at all levels of difficulty (158 ± 56 versus 187 ± 51 s, 176 ± 49 versus 222 ± 68 s, and 275 ± 76 versus 422 ± 220 s, at levels 1, 2, and 3, respectively, P < 0.05). Data on instrument path length, grasping tension, and errors showed a trend toward a benefit from haptics at all difficulty levels, but this difference did not achieve statistical significance.

Conclusions

In the more advanced tasks, haptics allowed superior precision, resulting in faster completion of tasks and a trend toward fewer technical errors. In the more basic tasks, haptic-enhanced simulation did not demonstrate an appreciable performance improvement among our trainees. These data suggest that the additional expense of haptic-enhanced laparoscopic simulators may be justified for advanced skill development in surgical trainees as simulator technology continues to improve.

Introduction

Laparoscopic virtual reality simulators are becoming a ubiquitous tool in resident training and assessment. These devices provide various levels of realism, including haptic (or force) feedback. The cost of these useful training tools is a significant deterrent to their acquisition for many programs, and the presence of force feedback adds significantly to the expense. Laparoscopy VR (Immersion Medical, Gaithersburg, MD) is a new generation of haptic-enhanced virtual reality simulator, which offers basic skills similar to the FLS drills, as well as full procedure simulation. The tasks preinstalled in the device can be adjusted over a wide range of scenarios to help focus the training experience. The simulator software also tracks multiple relevant performance metrics, including time to perform tasks, instrument path length, dexterity, missed objects, tissue damage, and grasping tension. Previous work demonstrated that performance on the Laparoscopy VR simulator correlated with surgical skill level as measured by two basic FLS tasks [1].

Limited data exist assessing the value of haptics in skill development. Utilizing the Laparoscopy VR, we hypothesized that the presence of force feedback in the simulated environment would allow superior trainee performance compared with performance of the same basic skills tasks in a non-haptic model.