Chris J. Hughes

Visual Supercomputing: Technologies, Applications and Challenges

If we were to have a Grid infrastructure for visualization, what technologies would be needed to build such an infrastructure, what kind of applications would benefit from it, and what challenges are we facing in order to accomplish this goal? In this survey paper, we make use of the term ‘visual supercomputing’ to encapsulate a subject domain concerning the infrastructural technology for visualization. We consider a broad range of scientific and technological advances in computer graphics and visualization, which are relevant to visual supercomputing. We identify the state‐of‐the‐art technologies that have prepared us for building such an infrastructure. We examine a collection of applications that would benefit enormously from such an infrastructure, and discuss their technical requirements. We propose a set of challenges that may guide our strategic efforts in the coming years.

Real-time Seldinger technique simulation in complex vascular models

PurposeCommercial interventional radiology vascular simulators emulate instrument navigation and device deployment, though none supports the Seldinger technique, which provides initial access to the vascular tree. This paper presents a novel virtual environment for teaching this core skill.MethodsOur simulator combines two haptic devices: vessel puncture with a virtual needle and catheter and guidewire manipulation. The simulation software displays the instrument interactions with the vessels. Instruments are modelled using a mass-spring approximation, while efficient collision detection and collision response allow real time interactions.ResultsExperienced interventional radiologists evaluated the haptic components of our simulator as realistic and accurate. The vessel puncture haptic device proposes a first prototype to simulate the Seldinger technique. Our simulator presents realistic instrument behaviour when compared to real instruments in a vascular phantom.ConclusionThis paper presents the first simulator to train the Seldinger technique. The preliminary results confirm its utility for interventional radiology training.

ImaGiNe Seldinger: First simulator for Seldinger technique and angiography training

In vascular interventional radiology, procedures generally start with the Seldinger technique to access the vasculature, using a needle through which a guidewire is inserted, followed by navigation of catheters within the vessels. Visual and tactile skills are learnt in a patient apprenticeship which is expensive and risky for patients. We propose a training alternative through a new virtual simulator supporting the Seldinger technique: ImaGiNe (imaging guided interventional needle) Seldinger. It is composed of two workstations: (1) a simulated pulse is palpated, in an immersive environment, to guide needle puncture and (2) two haptic devices provide a novel interface where a needle can direct a guidewire and catheter within the vessel lumen, using virtual fluoroscopy. Different complexities are provided by 28 real patient datasets. The feel of the simulation is enhanced by replicating, with the haptics, real force and flexibility measurements. A preliminary validation study has demonstrated training effectiveness for skills transfer.

Adaptive Infrastructure for Visual Computing

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.

Storyboarding for visual analytics

Analysts wish to explore different hypotheses, organize their thoughts into visual narratives and present their findings. Some developers have used algorithms to ascertain key events from their data, while others have visualized different states of their exploration and utilized free-form canvases to enable the users to develop their thoughts. What is required is a visual layout strategy that summarizes specific events and allows users to layout the story in a structured way. We propose the use of the concept of ‘storyboarding’ for visual analytics. In film production, storyboarding techniques enable film directors and those working on the film to pre-visualize the shots and evaluate potential problems. We present six principles of storyboarding for visual analytics: composition, viewpoints, transition, annotability, interactivity and separability. We use these principles to develop epSpread, which we apply to VAST Challenge 2011 microblogging data set and to Twitter data from the 2012 Olympic Games. We present technical challenges and design decisions for developing the epSpread storyboarding visual analytics tool that demonstrate the effectiveness of our design and discuss lessons learnt with the storyboarding method.

epSpread - Storyboarding for visual analytics

We present epSpread, an analysis and storyboarding tool for geolocated microblogging data. Individual time points and ranges are analysed through queries, heatmaps, word clouds and streamgraphs. The underlying narrative is shown on a storyboard-style timeline for discussion, refinement and presentation. The tool was used to analyse data from the VAST Challenge 2011 Mini-Challenge 1, tracking the spread of an epidemic using microblogging data. In this article we describe how the tool was used to identify the origin and track the spread of the epidemic.

Using a Kinect Interface to Develop an Interactive 3D Tabletop Display

Since the release of the motion picture ’Minority Report’ in 2002, which depicts Tom Cruise interacting with a video display using only hand gestures, there has been a significant interest in the development of intelligent display technology, that users are able to interact with using gestures. In the real world it is common place for us to use gestures and body language to re-enforce our communication. It therefore becomes very natural for us to want to interact with our virtual media in the same way. Traditional methods for pose recognition involve using cameras to track the position of the user. However this can be very challenging to complete acurately in a variety of environments where camera can become occluded or the lighting conditions can change. In this research we prototyped a 3D tabletop display and explored the Kinect game controller as a possible solution to tracking the pose and gesture of a user whilst interacting with our display.

A Flexible Approach to High Performance Visualization Enabled Augmented Reality

Traditionally registration and tracking within Augmented Reality (AR) applications have been built around limited bold markers, which allow for their orientation to be estimated in real-time. All attempts to implement AR without specific markers have increased the computational requirements and some information about the environment is still needed. In this paper we describe a method that not only provides a generic platform for AR but also seamlessly deploys High Performance Computing (HPC) resources to deal with the additional computational load, as part of the distributed High Performance Visualization (HPV) pipeline used to render the virtual artifacts. Repeatable feature points are extracted from known views of a real object and then we match the best stored view to the users viewpoint using the matched feature points to estimate the objects pose. We also show how our AR framework can then be used in the real world by presenting a markerless AR interface for Transcranial Magnetic Stimulation (TMS).