Developing a virtual reality environment in petrous bone surgery: a state-of-the-art review.
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Ear, Inner↗
Biomedical subjects
N W John
Publications and source records attributed to N W John.
Modelling concepts of proton eye radiotherapy.
Information concerning the application of proton beams in radiotherapy of ocular tumours is provided using conventional website technology by a number of treatment facilities around the world. We hypothesized, however, that many of the key concepts would be better conveyed by an interactive computer model utilizing virtual reality technology. We describe the implementation, using Virtual Reality Modelling Language (VRML), of such a model, the Proton Therapy Concepts Demonstrator (PTCD). The World-Wide-Web-accessible PTCD is intended to provide information useful both to trainee and to qualified clinical staff and also to patients. A model was created of the radiotherapy room that was linked to an interactive model depicting a simple explanation of the process of proton eye radiotherapy. This model also allows the user to explore specific elements of the treatment planning and delivery process, such as beam collimation and range modulation. A further level of detail has been provided by a dynamic model demonstrating how a specific modulated dose distribution is achieved as the time integration of discrete modulated Bragg peaks. We believe this VR-based model has the potential of enabling users to gain more rapid insight into the proton therapy process. Its development as an educational tool is continuing, following feedback collected from clinical staff and patients.
Computer-Assisted Instruction↗
Web-based surgical educational tools.
This paper describes work being undertaken as part of the WebSET (Web-based Standard Educational Tools) project. The project is producing a standardised suite of interactive three-dimensional educational tools, delivered across the WWW. The major focus will be the use of open technology and standards, and the production of learning components that can be used as building blocks for further development in a wide range of application areas. Two learning disciplines have been selected for the development of the WebSET tools: surgical training, and physiological education. A high quality consortium from across Europe has been assembled with complementary skills in the technologies needed by the project. The project is partly funded by the European Commission.
Curriculum↗
An integrated simulator for surgery of the petrous bone.
This paper describes work being undertaken as part of the IERAPSI (Integrated Environment for the Rehearsal and Panning of Surgical Intervention) project. The project is focussing on surgery for the petrous bone, and brings together a consortium of European clinicians and technology providers working in this field. The paper presents the results of a comprehensive user task analysis that has been carried out in the first phase of the IERAPSI project, and details the current status of development of a pre operative planning environment and a physically-based surgical simulator.
Cochlear Implantation↗
Force-feedback in Web-based surgical simulators.
There is a growing requirement in the field of surgical training to allow trainees to practice procedures in a way that does not place patients in any risk. Computer based simulators allow students to gain experience and develop three-dimensional awareness in a safe and controlled environment. Typically systems that have been developed to perform this task are, due to their specialist nature, expensive to buy. With the increasing availability of Force-Feedback devices for the gaming market, is there now a cost-effective alternative for surgical simulations? In this paper we investigate the possibility of using such a device as a haptic input tool for surgical simulations.
Computer Simulation↗
Web-based surgical simulation for ventricular catheterization.
We have used new developments in computer technology and the Internet to create a small program that simulates catheterization of the lateral ventricle. The program can run on most personal computers connected to the Internet. The program allows trainee surgeons to practice the technique with varying degrees of visual feedback--and no risk to the patient. It allows them to learn both the technique and the associated anatomy. The trainees can be assessed while performing the procedure. This is a small, early-stage application of virtual reality in surgical education. There is a demand for surgical training techniques that expose the patient to no risk; the use of computers is appropriate to meet this demand. The technique presented here requires further development; in particular, it needs a standardized assessment element that will allow it to be tested by established surgeons and trainees. The real test of a good training technique is how well it discriminates between trainee and trainer.
Cerebral Ventricles↗
Surgical simulators using the WWW.
This paper will describe a suite of surgical simulators that we have designed and implemented to run on the WWW. The procedures that have been modelled include simulations of ventricular catheterisation, and lumbar puncture. We will present a detailed overview of implementation and operation of these simulators, and indicate results from early use. The advantages and disadvantages of our approach will be discussed.
Catheterization↗
Noninvasive 3-D ultrasound of atherosclerotic plaques in the Watanabe rabbit.
We have investigated the ability to quantitate atherosclerosis in the aortic arch of the Watanabe rabbit using noninvasive 3-D ultrasound. Our methodology utilizes postprocessing of videotaped freehand 2-D interrogations to form a compound 3-D data block. Structures may then be segmented on the attributed grey-scale level and volumes measured. Analysis of 3-D reconstructions revealed a low echo structure in the aortic arch of atherosclerotic rabbits, absent in nonatherosclerotic rabbits, at recognized sites of plaque predilection. This structure volume correlated closely with fatty streak volume determined from histology (r = 0.890). During a 30-week study, this structure volume increased in untreated animals, but was blocked by treatment with the antiatherosclerotic agent probucol. Thus, a new 3-D ultrasound methodology has been used noninvasively to detect and quantitate a low echo structure corresponding to fatty streaks in the Watanabe rabbit aortic arch. This new methodology could potentially aid plaque burden quantification in human peripheral arteries.
Algorithms↗
Medical volume rendering over the WWW using VRML and JAVA.
The rapid growth of the World Wide Web (WWW) enables access to huge amounts of data and applications. The diversity of data-structures and applications has led to the concept of network computing where the data is encapsulated within the application. The end-user does not have to worry about tools for data manipulation as they are bundled together with the data itself. However, the user usually has to pay a price in the form of degraded performance. While JAVA is gradually taking its place as the network cross platform programming language, it is clear that it currently does not support high-performance visualization. The purpose of this paper is to demonstrate that high performance volume rendering, traditionally reserved for high-end visual computing, can now be made widely available in a cross-platform fashion using VRML and JAVA.
Algorithms↗
Three-dimensional freehand ultrasound: image reconstruction and volume analysis.
A system is described that rapidly produces a regular 3-dimensional (3-D) data block suitable for processing by conventional image analysis and volume measurement software. The system uses electromagnetic spatial location of 2-dimensional (2-D) freehand-scanned ultrasound B-mode images, custom-built signal-conditioning hardware, UNIX-based computer processing and an efficient 3-D reconstruction algorithm. Utilisation of images from multiple angles of insonation, "compounding," reduces speckle contrast, improves structure coherence within the reconstructed grey-scale image and enhances the ability to detect structure boundaries and to segment and quantify features. Volume measurements using a series of water-filled latex and cylindrical foam rubber phantoms with volumes down to 0.7 mL show that a high degree of accuracy, precision and reproducibility can be obtained. Extension of the technique to handle in vivo data sets by allowing physiological criteria to be taken into account in selecting the images used for construction is also illustrated.
Algorithms↗