Gregory J. Wiet

Virtual temporal bone dissection: An interactive surgical simulator

OBJECTIVE: Our goal was to integrate current and emerging technology in virtual systems to provide a temporal bone dissection simulator that allows the user interactivity and realism similar to the cadaver laboratory. STUDY DESIGN: Iterative design and validation of a virtual environment for simulating temporal bone dissection. SETTING: University otolaryngology training program with interdisciplinary interaction in a high-performance computer facility. RESULTS: The system provides visual, force feedback (haptic), and aural interfaces. Unlike previous “fly through” virtual systems, this environment provides a richer emulation of surgical experience. CONCLUSION: The system provides a high level of functional utility and, through initial evaluations, demonstrates promise in adding to traditional training methods. SIGNIFICANCE: The system provides an environment to learn temporal bone surgery in a way similar to the experience with cadaver material where the subject is able to interact with the data without constraints (nondeterministic). Eventually, it may provide the “front end” to a large repository of various temporal bone pathologies that can be accessed through the Internet.

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 devices 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. Laryngoscope, 108:1643–1647, 1998

Percutaneous treatment of lymphatic malformations.

OBJECTIVE: The aim of this study is to investigate a new treatment regimen for macrocystic and microcystic lymphatic malformations (LM) of the head and neck. STUDY DESIGN: The study represents a retrospective review of outcomes from new percutaneous treatments for lymphatic malformations. SUBJECTS AND METHODS: Thirty-one patients (age range, 2 days to 51 years of age) underwent percutaneous treatment for LM of the head and neck from 2001 to 2007. The LM involved the orbit, ear, parotid gland, face, and neck. Twenty-seven patients underwent primary treatment of LM; 4 were treated for recurrence after operative resection. Macrocysts ≥1 cm) were treated with dual-drug chemoablation (sequential intracystic sodium tetradecyl sulfate and ethanol); doxycycline was used for microcysts. Macrocysts and microcysts were treated after complete cyst aspiration with sonographic guidance. Fifty-four macrocysts and 125 microcysts were treated. The goal of treatment was complete cyst ablation documented by sonography or MR imaging. RESULTS: Mean number of treatments was 1.7 per patient; mean number of treatments for macrocysts was 1.1; mean treatments for microcysts was 1.7. Ablation efficacy was 179 of 179 (100%) cysts. Effective cyst ablation achieved effective clinical control with resolution of the external mass appearance. Treatments included massive head and neck mixed LM and cysts surrounding the facial nerve and brachial plexus. Infection occurred in 2 (6%) of 31 patients. No patient experienced postprocedural pain, skin necrosis, neuropathy, skin retraction, or myoglobinuria. CONCLUSION: Percutaneous sclerotherapy provides effective treatment for macrocystic and microcystic LM as primary treatment or for recurrence after surgical resection.

Virtual temporal bone dissection: a case study

The Temporal Bone Dissection Simulator is an ongoing research project for the construction of a synthetic environment suitable for virtual dissection of human temporal bone and related anatomy. Funded by the National Institute on Deafness and Other Communication Disorders (NIDCD), the primary goal of this project is to provide a safe, robust, and cost-effective virtual environment for learning the anatomy and surgical procedures associated with the temporal bone. Direct volume visualization has been indispensable for the necessary level of realism and interactivity that is vital to the success of this project. This work is being conducted by the Ohio Supercomputer Center in conjunction with the Department of Otolaryngology at the Ohio State University, and NIDCD.

Reliability of the Welling Scale (WS1) for Rating Temporal Bone Dissection Performance

Objective: To determine the inter‐ and intrarater reliability of using a new scale (Welling scale) for resident evaluation of temporal bone dissection performance.

Use of ultra-high-resolution data for temporal bone dissection simulation

OBJECTIVES: For the past 5 years, our group has been developing a virtual temporal bone dissection environment for training otologic surgeons. Throughout the course of our development, a recurring challenge is the acquisition of high-resolution, multimodal, and multi-scale data sets that are used for the visual as well as haptic (sense of touch) display. This study presents several new techniques in temporal bone imaging and their use as data for surgical simulation. METHODS: At our institution (OSU), we are fortunate to have a high-field (8 Tesla) magnetic resonance imaging (MRI) research magnet that provides an order of magnitude higher resolution compared to clinical 1.5T MRI scanners. Magnetic resonance imaging has traditionally been superb at delineating soft tissue structure, and certainly, the 8T unit does indeed do this at a resolution of 100-200 μm3. To delineate the bony structure of the mastoid and middle ear, computed tomography (CT) has traditionally been used because of the high signal-to-noise ratio delineating bone signal from air and soft tissue. We have partnered with researchers at other institutions (CCF) to make use of a “microCT” that provides a resolution of 214 × 214 × 390 micrometers of bony structure. RESULTS: This report provides a description of the 2 methodologies and presentation of the striking image data capable of being generated. See images presented. CONCLUSIONS: Using these 2 new and innovative imaging modalities, we provide an order of magnitude greater resolution to the visual and haptic display in our temporal bone dissection simulation environment.

Training and Simulation in Otolaryngology

This article focuses on key issues surrounding the needs and application of simulation technologies for technical skills training in otolaryngology. The discussion includes an overview of key topics in training and learning, the application of these issues in simulation environments, and the subsequent applications of these simulation environments to otolaryngology. Examples of past applications are presented, with discussion of how the interplay of cultural changes in surgical training in general along with the rapid advancements in technology have shaped and influenced their adoption and adaptation. The authors conclude with emerging trends and potential influences advanced simulation and training will have on technical skills training in otolaryngology.

Epitope mapping immunodominant regions of the PilA protein of nontypeable Haemophilus influenzae (NTHI) to facilitate the design of two novel chimeric vaccine candidates.

We designed and tested three PilA-derived vaccine candidates in a chinchilla model of ascending nontypeable Haemophilus influenzae (NTHI)-induced otitis media (OM). Delivery of antiserum directed against each immunogen conferred varying degrees of protection. Presentation of a B-cell epitope derived from the OMP P5 adhesin at the N-terminus of recombinant soluble PilA protein (as opposed to the C-terminus), resulted in a protective chimeric immunogen that combined epitopes from two distinct NTHI adhesins (type IV pili and OMP P5). Incorporating protective epitopes derived from two NTHI adhesins/virulence determinants into a single pediatric vaccine candidate to prevent OM has multiple potential inherent advantages.

Building a virtual environment for endoscopic sinus surgery simulation

Abstract Advanced display technologies have made the virtual exploration of relatively complex models feasible in many applications. Unfortunately, only a few human interfaces allow natural interaction with the environment. Moreover, in surgical applications, such realistic interaction requires real-time rendering of volumetric data—placing an overwhelming performance burden on the system. We report on our advances towards developing a virtual reality system that provides intuitive interaction with complex volume data by employing real-time realistic volume rendering and convincing forece feedback (haptic) sensations. We describe our methods for real-time volume rendering, model deformation, interaction, and the haptic devices, and demonstrate the utilization of this system in the real-world application of Endoscopic Sinus Surgery (ESS) simulation.

Virtual temporal bone dissection system: OSU virtual temporal bone system: development and testing.

The objective of this project was to develop a virtual temporal bone dissection system that would provide an enhanced educational experience for the training of otologic surgeons.