Face Validation of a Virtual Translumenal Endoscopic Surgery Trainer (VTEST(TM))

Kurt Roberts, MD, FACS1, Denis Dorozhkin, PhD2, Woojin Ahn, PhD2, Tansel Halic, PhD3, Ganesh Sankaranarayanan, PhD2, Suvranu De, ScD2. 1Yale School of Medicine, 2Rensselaer Polytechnic Institute, 3University of Central Arkansas


Virtual Translumenal Endoscopic Surgical Trainer (VTEST™) is the first virtual reality simulator for the Natural Orifice Translumenal Endoscopic Surgery (NOTES). VTEST™ was developed to train surgeons in the hybrid transvaginal NOTES cholecystectomy procedure. The initial version of the simulator was face validated at the 2013 Natural Orifice Surgery Consortium for Assessment and Research (NOSCAR) summit. Several areas of improvement were identified as a result, and the corresponding modifications were implemented in the simulator. A subsequent evaluation study to assess the face validity of the latest VTEST™ version was performed.


A total of twelve subjects with varying NOTES experience (6 experts and 6 novices) participated in this Institutional Review Board (IRB) approved study. The study took place at the 2014 NOSCAR summit. The subjects were asked to perform the hybrid transvaginal NOTES cholecystectomy procedure on VTEST™. The subjects were then asked to answer a 5-point Likert scale feedback questionnaire consisting of fifteen questions: (1) realism of the anatomy, (2) realism in identification of the Calot's triangle, (3) simulator interface realism, (4) rigid scope navigation realism, (5) instrument handling realism, (6) overall realism of the blunt dissection task, (7) overall realism of the gallbladder removal task, (8) overall realism compared to the traditional laparoscopic tasks, (9) force feedback quality, (10) usefulness of the force feedback in performing the tasks (11) usefulness in learning hand-eye coordination (12) usefulness in learning ambidexterity skills, (13) overall usefulness in learning the fundamental NOTES skills (14) trustworthiness of the simulator in quantifying accurate measures of performance (15) trustworthiness of the simulator in providing different hand-eye coordination compared to traditional two-port laparoscopic approach.


Overall subjects rated 9 of the questions above 3 or greater (60%), including the realism of the anatomical features, interface and the tasks (Table 1). However, the results also show that further improvements are needed in blunt dissection and the force feedback quality. The corresponding functionality was newly developed for the 2014 NOSCAR summit, so a certain level of criticism was expected. These points are being addressed in the next iteration of the simulator.

Table 1: Descriptive statistics obtained from the questionnaire study


The face validity of the latest version of the virtual reality NOTES simulator VTEST™ was successfully established on many aspects of the simulation. Further refinements are currently taking place in order to improve the VTEST™ simulator based on the face validation feedback.

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