Mary Rasmussen

Virtual temporal bone: Creation and application of a new computer-based teaching tool☆☆☆

The human temporal bone is a 3-dimensionally complex anatomic region with many unique qualities that make anatomic teaching and learning difficult. Current teaching tools have proved only partially adequate for the needs of the aspiring otologic surgeon in learning this anatomy. We used a variety of computerized image processing and reconstruction techniques to reconstruct an anatomically accurate 3-dimensional computer model of the human temporal bone from serial histologic sections. The model is viewed with a specialized visualization system that allows it to be manipulated easily in a stereoscopic virtual environment. The model may then be interactively studied from any viewpoint, greatly simplifying the task of conceptualizing and learning this anatomy. The system also provides for simultaneous computer networking that can bring distant participants into a single shared virtual teaching environment. Future directions of the project are discussed.

Three dimensional virtual reality model of the normal female pelvic floor

The anatomy of the pelvic floor is complex and difficult to visualize from conventional two-dimensional anatomy pictures. The goal of this project was to establish the methods necessary to develop a static three-dimensional virtual reality model of the normal female pelvic floor from high-resolution magnetic resonance imaging (MRI) scans. An asymptomatic nulliparous 23-year-old female with no urinary incontinence symptoms underwent a high-resolution pelvic floor MRI scan. Selected pelvic floor structures were manually segmented: bladder, urethra, vagina, uterus, cervix, levator ani, obturator externus, obturator internus, and pubic bone. With high-resolution scans, accurate segmentation of the structures was possible. The completed models were displayed on an ImmersaDesk Virtual Reality system and three clinicians verified their accuracy. Stereovision glasses were used to enhance the model while a receiver tracked head position. Three-dimensional virtual reality models of the female pelvic floor can enhance our understanding of anatomy and physiology of this complex part of the body. They can be used as tools for both research and teaching, facilitating improved treatment of pelvic floor pathologies.

Virtual reality: new method of teaching anorectal and pelvic floor anatomy.

AbstractPURPOSE: A clear understanding of the intricate spatial relationships among the structures of the pelvic floor, rectum, and anal canal is essential for the treatment of numerous pathologic conditions. Virtual-reality technology allows improved visualization of three-dimensional structures over conventional media because it supports stereoscopic-vision, viewer-centered perspective, large angles of view, and interactivity. We describe a novel virtual reality-based model designed to teach anorectal and pelvic floor anatomy, pathology, and surgery. METHODS: A static physical model depicting the pelvic floor and anorectum was created and digitized at 1-mm intervals in a CT scanner. Multiple software programs were used along with endoscopic images to generate a realistic interactive computer model, which was designed to be viewed on a networked, interactive, virtual-reality display (CAVE® or ImmersaDesk®). A standard examination of ten basic anorectal and pelvic floor anatomy questions was administered to third-year (n = 6) and fourth-year (n = 7) surgical residents. A workshop using the Virtual Pelvic Floor Model was then given, and the standard examination was readministered so that it was possible to evaluate the effectiveness of the Digital Pelvic Floor Model as an educational instrument. RESULTS: Training on the Virtual Pelvic Floor Model produced substantial improvements in the overall average test scores for the two groups, with an overall increase of 41 percent (P = 0.001) and 21 percent (P = 0.0007) for third-year and fourth-year residents, respectively. Resident evaluations after the workshop also confirmed the effectiveness of understanding pelvic anatomy using the Virtual Pelvic Floor Model. CONCLUSION: This model provides an innovative interactive educational framework that allows educators to overcome some of the barriers to teaching surgical and endoscopic principles based on understanding highly complex three-dimensional anatomy. Using this collaborative, shared virtual-reality environment, teachers and students can interact from locations world-wide to manipulate the components of this model to achieve the educational goals of this project along with the potential for virtual surgery.

The virtual temporal bone, a tele-immersive educational environment

Abstract This paper describes the development of the virtual temporal bone, a new method of teaching the complex anatomy of the middle and inner ear utilizing virtual reality and current networking technology. Virtual reality technology allows a better visualization of these three-dimensional structures than conventional media because it supports stereo vision, viewer-centered perspective, large angles of view, and interactivity. Two or more ImmersaDeskTM systems, drafting table format virtual reality displays, are networked together providing an environment where teacher and student share a high quality three-dimensional anatomical model, and are able to converse and to point in three dimensions to indicate areas of interest. This project was realized by the teamwork of otologic surgeons, medical artists and sculptors, computer scientists and computer visualization experts.

Computer-aided forensic facial reconstruction

The reconstruction of facial features on the human skull for identification purposes has, in the past, utilized either two-dimensional drafting or three-dimensional sculpting techniques. We have developed two- and three-dimensional computer-aided routines to minimize errors introduced by limits of artistic ability or by inconsistencies in the application of techniques. These routines allow generalized facial features to be manipulated to conform to the size and shape of a specific skull. Subtle alterations of the surface form, texture, and color, based on age, sex, and race, enhance the individuality of the generated facial form.

Radiological Tele-immersion

It is important to make patient-specific data quickly available and usable to many specialists at different geographical sites. A tele-immersive radiological system has been developed for remote consultation, surgical preplanning, postoperative evaluation, and education. Tele-immersive devices include personal augmented reality immersive system, configurable wall, physician’s personal virtual reality display, ImmersaDesk, volume rendering, cluster-based visualization of large-scale volumetric data, tele-immersive collaboration, and system implementation.

Biomedical Modeling in Tele-Immersion

The major goal of this research is to develop a networked collaborative surgical system for tele-immersive consultation, surgical pre-planning, implant design, post operative evaluation and education. Tele-immersion enables users in different locations to collaborate in a shared, virtual, or simulated environment as if they are in the same room. The process of implant design begins with CT data of the patient and the Personal Augmented Reality Immersive System (PARISTM). The implant is designed by medical professionals in tele-immersive collaboration. In the PARIS augmented reality system the users hands and the virtual images appear superimposed in the same volume so the user can see what he is doing. A haptic device supplies the sense of touch by applying forces to a stylus that the medical modeler uses to form the implant. After the virtual model of the implant is designed, the data is sent via network to a stereolithography rapid prototyping system that creates the physical implant model. After implant surgery, the patient undergoes a postoperative CT scan and results are evaluated and reviewed over the tele-immersive consultation system.

Methods of development of a three dimensional model of the normal female pelvic floor

The anatomy of the pelvic floor is complex and the structures interact in non-obvious ways to maintain continence. Thus, a visualizable model would help our understanding of this part of the body. The goal of this project was to establish the methods necessary to develop a static three-dimensional (3D) model of the normal female pelvic floor. An asymptomatic nulliparous twenty-three year old female with no urinary incontinence symptoms underwent a pelvic floor MRI scan. Manual segmentations were done of selected pelvic floor structures: bladder, urethra, vagina, uterus, cervix, levator ani, obturator externus, obturator internus, and pubic bone (Mimics, Materialise). 3 clinicians verified accuracy of the 3D models. With high-resolution scans, accurate segmentation of the structures was possible. Three-dimensional models of the female pelvic floor could enhance our understanding of anatomy. They can be used as tools for research and teaching, facilitating improved treatment of pelvic floor pathologies.

Development of a virtual reality model of the normal female pelvic floor

The anatomy of the pelvic floor is complex and difficult to visualize. Thus, a virtual reality (VR) model could be useful both for teaching and research. The aim of this project was to develop a static three-dimensional (3-D) VR model of the normal female pelvic floor. An asymptomatic nulliparous twenty-three year old female with no urinary incontinence symptoms underwent a high resolution pelvic floor magnetic resonance imaging (MRI) scan. Manual segmentation of selected pelvic floor structures were performed. 3-D models were then created and edited. The completed models were displayed on an ImmersaDesk VR system. Stereovision glasses were used to enhance the model while a receiver tracked head position. The VR models accurately displayed the anatomy of the female pelvic floor. A 3-D VR model of the female pelvic floor could be used to enhance our understanding of anatomy and physiology of this complex part of the body. It could be used as a tool for both teaching and research, promoting improved treatment of pelvic floor pathologies.