Nigel John

University of Chester, Computer Science, Faculty Member

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Papers by Nigel John

Medical visualization and virtual environments

Eurographics, 2004

Advanced graphics behind medical virtual reality: evolution of algorithms, hardware, and software interfaces

Proceedings of the IEEE, 1998

in medicine require real-time visualization and modeling of large three-dimensional data sets. Co... more

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Chemical education using feelable molecules

Proceedings of the 14th International Conference on 3D Web Technology - Web3D '09, 2009

Two different approaches for the preparation of novel cost-effective molecular haptic application... more Two different approaches for the preparation of novel cost-effective molecular haptic applications ( ) are described. The former utilises Perl scripting within a commercial molecular modelling package to generate static / animated H3D scene graphs for haptic CPK space-filling atomic perception. Within the second approach, key chemical concepts such as reactivity, aciditity and periodicity can be investigated using prototype H3D user interfaces.

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Quantizing the void: extending Web3D for space-filling haptic meshes

Studies in health technology and informatics, 2011

In this paper we summarize the progress of the Web3D scene graph model, and associated standards,... more In this paper we summarize the progress of the Web3D scene graph model, and associated standards, specifically Extensible 3D (X3D) in the domain of medical simulation. Historically, the Web3D nodesets have focused on the representation and rendering of point, line or surface geometry. More recently, significant progress in X3D Volume rendering has been made available through the co-operative DICOM work item, n-Dimensional Presentation States. However, here we outline the need for a standard for simulation meshes and review several related approaches. As a result, we propose preliminary requirements for a simulation mesh standard and provide several use case scenarios of how Web3D and haptic technologies can aid the fulfillment of these requirements. We conclude with an X3D proposal to describe simulation meshes for soft (deformable) bodies.

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Augmented reality for anatomical education

Journal of visual communication in medicine, 2010

The use of Virtual Environments has been widely reported as a method of teaching anatomy. General... more The use of Virtual Environments has been widely reported as a method of teaching anatomy. Generally such environments only convey the shape of the anatomy to the student. We present the Bangor Augmented Reality Education Tool for Anatomy (BARETA), a system that combines Augmented Reality (AR) technology with models produced using Rapid Prototyping (RP) technology, to provide the student with stimulation for touch as well as sight. The principal aims of this work were to provide an interface more intuitive than a mouse and keyboard, and to evaluate such a system as a viable supplement to traditional cadaver based education.

Modelling concepts of proton eye radiotherapy

Physiological Measurement, 2001

Information concerning the application of proton beams in radiotherapy of ocular tumours is provi... more 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.

Visualizing the Surface of a Living Human Brain

IEEE Computer Graphics and Applications, 2000

A proposed method visualizes the surface appearance of living human brain tissue. The goal is to ... more A proposed method visualizes the surface appearance of living human brain tissue. The goal is to investigate whether realistic models of living anatomy are possible and, if so, whether they provide added value to anatomy education and training simulators. From calibrated photography of exposed brain tissue and suitable alternatives, experiments provided data for a bidirectional reflectance distribution function, which was then used for rendering. Employing a GPU, real-time visualization of the brain&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s surface supported ambient occlusion, advanced texturing, subsurface scattering, and specularity.

Principles and Applications of Computer Graphics in Medicine

Computer Graphics Forum, 2006

The medical domain provides excellent opportunities for the application of computer graphics, vis... more The medical domain provides excellent opportunities for the application of computer graphics, visualization, and virtual environments, with the potential to help improve healthcare and bring benefits to patients. This survey paper provides a comprehensive overview of the state-of-the-art in this exciting field. It has been written from the perspective of both computer scientists and practising clinicians and documents past and current successes together with the challenges that lie ahead. The article begins with a description of the software algorithms and techniques that allow visualization of and interaction with medical data. Example applications from research projects and commercially available products are listed, including educational tools; diagnostic aids; virtual endoscopy; planning aids; guidance aids; skills training; computer augmented reality; and use of high performance computing. The final section of the paper summarises the current issues and looks ahead to future developments.

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Touching the invisible-molecular haptics

A visualization system for the clinical evaluation of cerebral aneurysms from mra data

The software has been designed to meet the specific needs of interventional neuro-radiologists ev... more The software has been designed to meet the specific needs of interventional neuro-radiologists evaluating the suitability of intracranial aneurysms for endovascular coiling and also when planning the procedure. Providing rapid (real-time) interaction with high resolution iso-surfaces derived from Time-of Flight (ToF) Magnetic Resonance Angiography (MRA) data will enable the clinician to quickly assess the ability of the aneurysm to accept a coil, with greater reliability than exisiting, 2D film techniques. Simulating the interface of the C-arm angiography system, used during the procedure, allows the clinician to evaluate various surgical strategies, potentially reducing procedure times and therefore patient radiation dosage. The first release of the software is currently under-going clinical evaluation.

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Adaptive infrastructure for visual computing

Recent hardware and software advances have demonstrated that it is now practicable to run large v... more Recent hardware and software advances have demonstrated that it is now practicable to run large visual computing tasks over heterogeneous hardware with output on multiple types of display devices. As the complexity of the enabling infrastructure increases, then so too do the demands upon the programmer for task integration as well as the demands upon the users of the system. This places importance on system developers to create systems that reduce these demands. Such a goal is an important factor of autonomic computing, aspects of which we have used to influence our work. In this paper we develop a model of adaptive infrastructure for visual systems. We design and implement a simulation engine for visual tasks in order to allow a system to inspect and adapt itself to optimise usage of the underlying infrastructure. We present a formal abstract representation of the visualization pipeline, from which a user interface can be generated automatically, along with concrete pipelines for the visualization. By using this abstract representation it is possible for the system to adapt at run time. We demonstrate the need for, and the technical feasibility of, the system using several example applications. * K.W. Brodlie and J.D. Wood are with University of Leeds; J. Brooke, M. Turner and M. Riding are with University of Manchester; M. Chen, D. Chisnall, M.W. Jones and N. Roard are with Swansea University; and C. Hughes and N.W. John are with Bangor University

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Efficacy of a Virtual Environment for Training Ball Passing Skills in Rugby

by Daniel Mestre, Gavin Lawrence, Nigel John, and kenton morgan

Segmentation of Radiological Images

Medical Radiology, 2008

Page 1. Segmentation of Radiological Images 45 NW John, PhD Professor of Computing, School of Com... more

Volume Rendering

Medical Radiology, 2002

Visualization of molecular quantum dynamics

Proceedings of the tenth international conference on 3D Web technology - Web3D '05, 2005

The Department of Chemistry and the School of Informatics at the University of Wales, Bangor are ... more The Department of Chemistry and the School of Informatics at the University of Wales, Bangor are working together to create tools for the visualization of molecular quantum dynamics. This paper presents the results of our initial work. A prototype Molecular Visualiser (MV) application has been developed based on Web3D standards, plus extensions for support of haptic interaction. MV provides the user with visualizations of molecular systems, potential energy surfaces, and wavepacket dynamics. These can be displayed in a web browser using VRML, or be delivered to a virtual environment in which haptic properties have been assigned based on the molecular dynamics of the system. The use of MV for both research and teaching is discussed.

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Using stereoscopy for medical virtual reality

Studies in health technology and informatics, 2002

The use of stereoscopy to enhance the immersive experience obtained from a virtual environment is... more The use of stereoscopy to enhance the immersive experience obtained from a virtual environment is well known, and many medical applications can benefit from this technology. The stereoscopic projection sessions at the last two MMVR conferences contain many excellent examples. Stereoscopy need not be expensive to implement, and can easily be provided on a desktop PC. This paper looks at the different options available today, from active stereo, to passive stereo, to autostereoscopic displays, and their deployment on both high-end and low-end systems. The potential benefits of these different approaches are illustrated with examples from medical visualisation projects currently being carried out at the Manchester Visualization Centre (MVC).

An integrated simulator for surgery of the petrous bone

by Nigel John, Andrea Giachetti, and G. Zanetti

Studies in health technology and informatics, 2001

This paper describes work being undertaken as part of the IERAPSI (Integrated Environment for the... more 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.

Mastoidectomy simulation with combined visual and haptic feedback

by Nigel John and Andrea Giachetti

Studies in health technology and informatics, 2002

Mastoidectomy is one of the most common surgical procedures relating to the petrous bone. In this... more Mastoidectomy is one of the most common surgical procedures relating to the petrous bone. In this paper we describe our preliminary results in the realization of a virtual reality mastoidectomy simulator. Our system is designed to work on patient-specific volumetric object models directly derived from 3D CT and MRI images. The paper summarizes the detailed task analysis performed in order to define the system requirements, introduces the architecture of the prototype simulator, and discusses the initial feedback received from selected end users.

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Cybermedicine Tools for Communication and Learning

Journal of Visual Communication in Medicine, 2007

The medical domain provides excellent opportunities for communication and teaching of healthcare ... more The medical domain provides excellent opportunities for communication and teaching of healthcare issues using computer graphics, visualization techniques, and virtual environments. Possible applications include anatomical educational tools; patient education; diagnostic aids; virtual autopsies; planning and guidance aids; skills training; and computer augmented reality. Both clinicians and patients can benefit from the appropriate use of tools that make use of these technologies. This paper provides an overview of the state-of-the-art technologies in this exciting field, including detailed examples from our research. The term cybermedicine is discussed and issues for effective cybermedicine are highlighted.

Noninvasive 3-D ultrasound of atherosclerotic plaques in the Watanabe rabbit

Ultrasound in medicine & biology, 1999

We have investigated the ability to quantitate atherosclerosis in the aortic arch of the Watanabe... more 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.

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