Functional endoscopic sinus surgery training simulator.

OBJECTIVE/HYPOTHESIS: To determine the efficacy of a haptic (force feedback) device and to compare isosurface and volumetric models of a functional endoscopic sinus surgery (FESS) training simulator. STUDY DESIGN: A pilot study involving faculty and residents from the Department of Otolaryngology at The Ohio State University. METHODS: Objective trials evaluated the haptic device's ability to perceive three-dimensional shapes (stereognosis) without the aid of image visualization. Ethmoidectomy tasks were performed with both isosurface and volumetric FESS simulators, and surveys compared the two models. RESULTS: The haptic device was 77% effective for stereognosis tasks. There was a preference toward the isosurface model over the volumetric model in terms of visual representation, comfort, haptic-visual fidelity, and overall performance. CONCLUSIONS: The FESS simulator uses both visual and haptic feedback to create a virtual reality environment to teach paranasal sinus anatomy and basic endoscopic sinus surgery techniques to ear, nose, and throat residents. The results of the current study showed that the haptic device was accurate in and of itself, within its current physical limitations, and that the isosurface-based simulator was preferred.

Validation of the Madigan ESS simulator.

The Madigan Endoscopic Sinus Surgery (ESS) Simulator, developed by a multi-institution team led by Lockheed Martin, includes force-feedback instrument and virtual endoscope interaction with three-dimensional paranasal anatomy models derived from the Visible Human dataset, supplemented by a variety of graphical and auditory instructional aids embedded in the model. Our formal evaluation of Version 1.2 of the system focused on its validity as an ESS simulator. Run-time and survey data were collected for three groups of subjects on a common protocol progressing through the three basic ESS subtasks: navigation, injection, and dissection. Non-MD subjects performed the tasks on a simplified abstract virtual model with instructional aids (hoops for the navigation path, injection targets, dissection spheres, auditory feedback about task completion, and simulated patient heart rhythm). Non-ENT MDs progressed from this "novice" model to a simulated anterior ethmoidectomy on an "intermediate" model with the aids embedded in the reconstructed and segmented paranasal anatomy. Otolaryngologists ranging from second-year ENT residents through senior staff progressed through both the abstract and intermediate models, and then performed the simulated surgical procedure on an "advanced" model, consisting of the anatomy with no instructional aids. The procedural validity of the simulator is supported by a strong correlation between performance on the simulator and degree of prior ESS experience, by convergent correlation among independent measures of subject task performance, and by subjective evaluations by experienced ESS surgeons.

ENT endoscopic surgical training simulator.

This paper describes work in progress on the design and development of a prototype simulator for minimally invasive otolaryngology surgical training. The anatomy of the paranasal sinuses is geometrically complex and dangerously close to the brain and orbits, making this procedure challenging to practice and difficult to learn. We discuss the potential role of computer simulation to enhance and accelerate acquisition of surgical skills. The design goals of the prototype include high-fidelity simulation of the endoscopic imagery and haptic cues of surgical palpation. The prototype enables endoscopic navigation and limited interactive tissue manipulation and dissection tasks on a virtual patient using realistic replicas of surgical tools. We present an overview of the system architecture with a discussion of the technological challenges, design issues and current status of the efforts.