Objectives: The aim of our study was to evaluate the face and construct validity of VBLaST (Virtual Basic Laparoscopic Skills Trainer), a virtual reality simulator version of Fundamentals of Laparoscopic Surgery (FLS).
Methods: 31 subjects were categorized into 2 groups: 14 experts (PGY 5/fellows/faculty) & 17 novices (PGY 1-4). Subjects were randomized to perform 3 basic tasks (peg transfer, pattern cutting, and loop ligature) in both FLS box trainer and VBLaST haptics simulator. Questionnaire used a 5 point Likert scale to establish face validity and assess overall realism of tools and images, quality of force feedback, and the subjects’ ability to trust the simulator for performance measures. For construct validity, the FLS scoring system was utilized for both the FLS and VBLaST. Proctors calculated the FLS score, while software automatically scored for VBLaST tasks.
Results: For face validity, the quality of images were rated high (mean of 4.0), followed by realism of equipment (mean of 3.67). Quality of force feedback rating was at 2.64 and trust in the simulator at 2.83. Mann-Whitney U test between the 2 groups showed no significant difference of opinion between the expert and novice groups (p>0.51).
Construct validity scores from peg transfer and loop ligature tasks showed that VBLaST differentiated the 2 groups (p= 0.028). FLS did not differentiate between the 2 groups with just 2 tasks (p>0.2) but did when pattern cutting was included (p=0.004). VBLaST peg transfer alone was able to differentiate between the 2 groups (p=0.027).
Conclusions: Face validity scores demonstrated excellent image quality and overall realism. Higher fidelity is needed in force feedback quality to make this simulator acceptable as a scoring device. Construct validity results demonstrated that this VBLaST prototype is capable of differentiating between novices and experts but not at the fine resolution of FLS. Differences may be due to experts adapting more successfully to the VBLaST system. This is a significant first step towards a virtual reality FLS system.
Program Number: P245