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Biomedical subjects

Gregory J Wiet

Publications and source records attributed to Gregory J Wiet.

6 recordsLinked to original sources
PubMed2005

Emphatic, interactive volume rendering to support variance in user expertise.

Various levels of representation, from abstract to schematic to realistic, have been exploited for millennia to facilitate the transfer of information from one individual to another. Learning complex information, such as that found in biomedicine, proves specifically problematic to many, and requires incremental, step-wise depictions of the information to clarify structural, functional, and procedural relationships.Emerging volume-rendering technique, such as non-photorealistic representation, coupled with advances in computational speeds, especially new graphical processing units, provide unique capabilities to explore the use of various levels of representation in interactive sessions. We have developed a system that produces images that simulate pictorial representations for both scientific and biomedical visualization. The system combines traditional and novel volume illustration techniques. We present examples from our efforts to distill representational techniques for both creative exploration and emphatic presentation for clarity. More specifically, we present our efforts to adapt these techniques for interactive simulation sessions being developed in a concurrent project for resident training in temporal bone dissection simulation. The goal of this effort is to evaluate the use of emphatic rendering to guide the user in an interactive session and to facilitate the learning of complex biomedical information, including structural, functional, and procedural information.

Computational Biology↗
PubMed2003

The role of airway fluoroscopy in the evaluation of stridor in children.

OBJECTIVE: To determine the role of airway fluoroscopy in comparison with other diagnostic modalities in diagnosing the site of partial airway obstruction in children with stridor. DESIGN: Prospective study comparing direct laryngoscopy and bronchoscopy with nasopharyngoscopy, airway fluoroscopy, and plain films. Children with stridor or partial airway obstruction were evaluated by the Department of Otolaryngology at Columbus Children's Hospital, Columbus, Ohio. A history review and physical examination, including flexible fiberoptic laryngoscopy, plain films, airway fluoroscopy, and direct laryngoscopy and bronchoscopy, were performed for all children. SETTING: Tertiary care children's hospital. PATIENTS: From November 1996 to September 1999, 64 children aged 1 week to 12 years, with a mean age of 1.8 years and male-female ratio of 3:2, were evaluated for stridor. MAIN OUTCOME MEASURES: The sensitivity and specificity of airway fluoroscopy in diagnosing the site of partial airway obstruction in comparison with nasopharyngoscopy and plain films. RESULTS: Airway fluoroscopy had a sensitivity of 80% for subglottic, 73% for tracheal, and 80% for bronchial sites of obstruction. It was less sensitive for supraglottic and glottic sites-33% and 14%, respectively. Nasopharyngoscopy was more sensitive for supraglottic and glottic sites of obstruction. Overall, airway fluoroscopy was far more sensitive than plain films for diagnosing site of obstruction. CONCLUSIONS: Airway fluoroscopy is a quick, noninvasive, and dynamic study of the entire airway that provides important additional information to the history review and physical examination and is a valuable adjunct to flexible fiberoptic laryngoscopy. It was far superior to plain films and may serve as a cost-effective screening tool in the evaluation of stridor in children, especially for lesions of the lower airway.

Airway Obstruction↗
PubMed2002

Maxillary removal and reinsertion in pediatric patients.

OBJECTIVE: To examine outcomes after the maxillary removal and reinsertion (MRR) approach for the treatment of anterior cranial base tumors in pediatric patients. DESIGN: Eligible patients were identified by medical record review. Consenting patients were studied via rhinoscopy, fiberoptic endoscopy, standard facial photographs, and cephalometric radiographs. SETTING: A tertiary care otolaryngology clinic. PATIENTS: Inclusion criteria were age younger than 16 years at time of initial procedure and a follow-up period of at least 6 months. Nine patients were eligible, and 5 enrolled. All were male patients (mean age, 13.8 years; age range, 11-15 years) treated for juvenile nasopharyngeal angiofibroma. MAIN OUTCOME MEASURES: History and examination were performed to evaluate occlusion, vision, facial growth, and tumor status. Cephalograms were used to calculate 3 standard cephalometric measurements: sella to A point, basion to A point, and condylion to A point. Cephalograms were examined for plate migration and bony resorption. RESULTS AND CONCLUSIONS: No major long-term complications were identified in the patients after MRR. Cephalometric analysis revealed minor abnormalities in 2 children, but no plate migration or bony resorption was identified in the removed and reinserted maxillae. No abnormal development patterns were detected on physical examination or when cephalometric measurements were compared with age- and race-matched normative data. Although further study is warranted, MRR seems safe and effective for treatment of pediatric patients with anterior cranial base tumors.

Angiofibroma↗
PubMed2002

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.

Algorithms↗
PubMed2002

Temporal bone dissection simulation--an update.

We report on our continued development of a virtual simulation for temporal bone dissection that provides stereoscopic display, haptic feedback, and aural simulation into a straightforward, comprehensive learning environment. The multimodal interface provides a seamless simulation for non-deterministic drilling and cutting of bone in the surgical context, as well as an intuitive interface for the intelligent tutor for learning regional anatomy. We present novel methodologies for integrating multimodal and multiresolution data sets, including extension to functional and structural segmentation. We will present our initial efforts to validate this environment. Through continued iterations, it is our hope that the system will provide a valuable tool for training future otologic surgeons as well as an environment for the quantitative evaluation of surgical skill.

Aged↗