The Visual Display of Quantitative Information

This paper presents a new reflectance model for rendering computer synthesized images. The model accounts for the relative brightness of different materials and light sources in the same scene. It describes the directional distribution of the reflected light and a color shift that occurs as the reflectance changes with incidence angle. The paper presents a method for obtaining the spectral energy distribution of the light reflected from an object made of a specific real material and discusses a procedure for accurately reproducing the color associated with the spectral energy distribution. The model is applied to the simulation of a metal and a plastic.

A reflectance model for computer graphics

Barney Dalgarno is a research fellow with the Centre for Research in Complex Systems (CRiCS), Charles Sturt University, and an associate professor with the School of Education at the same university. His research interests lie in desktop virtual reality learning environments, as well as constructivist computerassisted learning theories, techniques and tools. Dalgarno’s PhD work examined the characteristics of 3-D environments and their potential contributions to spatial learning, and he is now studying the application of brain imaging though Functional Magnetic Resonance Imaging (fMRI) to interactive multimedia research. Mark J. W. Lee is an adjunct senior lecturer with the School of Education, Charles Sturt University. Previously, he worked in a variety of teaching, instructional design, and managerial roles within the private vocational education and higher education sectors. He has published approximately 50 refereed book chapters, journal articles, and conference papers in the areas of educational technology, e-learning, and innovative pedagogy in tertiary education. Lee is the Chair of the New South Wales Chapter of the IEEE Education Society and serves as founding Editor-in-Chief of Impact:Journal of Applied Research in Workplace E-learning, in addition to being on the editorial boards of a number of international journals. Address for correspondence: Mark J. W. Lee, School of Education, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia. Email: malee@csu.edu.au

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1467-8535.2009.01038.x

What are the learning affordances of 3-D virtual environments?

Medical Image Computing and Computer-Assisted Intervention

In this paper, we describe the state of the art in continuum robot manipulators and systems intended for application to interventional medicine. Inspired by biological trunks, tentacles, and snakes, continuum robot designs can traverse confined spaces, manipulate objects in complex environments, and conform to curvilinear paths in space. In addition, many designs offer inherent structural compliance and ease of miniaturization. After decades of pioneering research, a host of designs have now been investigated and have demonstrated capabilities beyond the scope of conventional rigid-link robots. Recently, we have seen increasing efforts aimed at leveraging these qualities to improve the frontiers of minimally invasive surgical interventions. Several concepts have now been commercialized, which are inspiring and enabling a current paradigm shift in surgical approaches toward flexible access routes, e.g., through natural orifices such as the nose. In this paper, we provide an overview of the current state of this field from the perspectives of both robotics science and medical applications. We discuss relevant research in design, modeling, control, and sensing for continuum manipulators, and we highlight how this work is being used to build robotic systems for specific surgical procedures. We provide perspective for the future by discussing current limitations, open questions, and challenges.

Continuum Robots for Medical Applications: A Survey

This review paper discusses the role of haptics within virtual medical training applications, particularly, where it can be used to aid a practitioner to learn and practice a task. The review summarizes aspects to be considered in the deployment of haptics technologies in medical training. First, both force/torque and tactile feedback hardware solutions that are currently produced commercially and in academia are reviewed, followed by the available haptics-related software and then an in-depth analysis of medical training simulations that include haptic feedback. The review is summarized with scrutiny of emerging technologies and discusses future directions in the field.

The Role of Haptics in Medical Training Simulators: A Survey of the State of the Art

Technical Section: A review of virtual environments for training in ball sports

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.

Three-dimensional freehand ultrasound: Image reconstruction and volume analysis

This paper presents a virtual environment for training femoral palpation and needle insertion, the opening steps of many interventional radiology procedures. A novel augmented reality simulation called PalpSim has been developed that allows the trainees to feel a virtual patient using their own hands. The palpation step requires both force and tactile feedback. For the palpation haptics effect, two off-the-shelf force feedback devices have been linked together to provide a hybrid device that gives five degrees of force feedback. This is combined with a custom built hydraulic interface to provide a pulse like tactile effect. The needle interface is based on a modified PHANTOM Omni end effector that allows a real interventional radiology needle to be mounted and used during simulation. While using the virtual environment, the haptics hardware is masked from view using chroma-key techniques. The trainee sees a computer generated patient and needle, and interacts using their own hands. This simulation provides a high level of face validity and is one of the first medical simulation devices to integrate haptics with augmented reality.

Integrating Haptics with Augmented Reality in a Femoral Palpation and Needle Insertion Training Simulation

This paper provides a survey of medical applications that make use of Web3D technologies, covering the period from 1995 to 2005. We assess the impact that Web3D has made on medical education and training during this time and highlight current and future trends. The applications identified are categorized into: general education tools; tools for diagnosis; procedures training; and collaborative training. A summary of work that has been carried out to validate these tools is also included in the survey.

Nigel W. John

Papers

The Role of Haptics in Medical Training Simulators: A Survey of the State of the Art

Technical Section: A review of virtual environments for training in ball sports

Three-dimensional freehand ultrasound: Image reconstruction and volume analysis

Integrating Haptics with Augmented Reality in a Femoral Palpation and Needle Insertion Training Simulation

The impact of Web3D technologies on medical education and training