Face Validity Study of an Artificial Temporal Bone for Simulation Surgery

Abstract

Using the rapid prototype (RP) technology, a physical construct of a human temporal bone was developed based on cadaveric tissue to permit simulated surgical training. The objective of the study was to test the face validity of the model. The cost and access to human cadaveric temporal bones is becoming increasingly challenging, particularly if there are religious and regulatory restrictions. There is a need to develop alternative strategies to improve accessibility. Ultra high-resolution computed tomography (CT) images (0.15-mm resolution) were obtained from a cadaver temporal bone. Manual segmentation and conversion into a stereolithography file format permitted printing on a RP stereolithography printer. A 3-dimensional physical model was hardened to achieve the desired consistency. Eight practicing otologists were recruited to evaluate this model. Respondents were asked to drill the artificial bone and complete a rating survey upon completion. In using a Likert scale between 1 and 5, results for anatomic accuracy were favorable, with the best scores for overall morphology (4.63) and for lateral structures within the bone (4.5). The poorest scores were for the semicircular canals (3.75) and chorda tympani (3.25). Scores for haptic realism were good as well. The average score for the question "overall, how valuable is the model as a surgical simulator" was 4.1. The experts felt that junior residents (PGY 1-3) would benefit most from this surgical education model. The outer structures of the RP artificial temporal bone can be considered to have face validity. Improvements will continue to be made to address some of the deficiencies in the anatomic and haptic realism of this model.