A smoothed particle hydrodynamics algorithm for haptic rendering of dental filling materials

Using haptic interfaces to assist the training of skills within the curriculum of undergraduate dentists provides a unique opportunity to advance rendering algorithms and engineering of haptic devices. In this paper we use the dental context to explore a rendering technique called smoothed particle hydrodynamics (SPH) as a potential method to train students on appropriate techniques for insertion of filling material into a previously prepared (virtual) dental cavity. The paper also considers how problems of haptic rendering might be implemented on a Graphical Processing Unit (GPU) that operates in the haptics control loop. The filling simulation used 3000 particles to represent the cavity boundary (approx. 1400 particles), tool (approx. 42 particles) and filling material (approx. 1600 particles), running at an average of 447Hz. Novel smoothing function in SPH was developed and its flexibility is presented

Real-time hybrid cutting with dynamic fluid visualization for virtual surgery

It is widely accepted that a reform in medical teaching must be made to meet today's high volume training requirements. Virtual simulation offers a potential method of providing such trainings and some current medical training simulations integrate haptic and visual feedback to enhance procedure learning. The purpose of this project is to explore the capability of Virtual Reality (VR) technology to develop a training simulator for surgical cutting and bleeding in a general surgery

Simulating molecular docking with haptics

Intermolecular binding underlies various metabolic and regulatory processes of the cell, and the therapeutic and pharmacological properties of drugs. Molecular docking systems model and simulate these interactions in silico and allow the study of the binding process. In molecular docking, haptics enables the user to sense the interaction forces and intervene cognitively in the docking process. Haptics-assisted docking systems provide an immersive virtual docking environment where the user can interact with the molecules, feel the interaction forces using their sense of touch, identify visually the binding site, and guide the molecules to their binding pose. Despite a forty-year research e�ort however, the docking community has been slow to adopt this technology. Proprietary, unreleased software, expensive haptic hardware and limits on processing power are the main reasons for this. Another signi�cant factor is the size of the molecules simulated, limited to small molecules. The focus of the research described in this thesis is the development of an interactive haptics-assisted docking application that addresses the above issues, and enables the rigid docking of very large biomolecules and the study of the underlying interactions. Novel methods for computing the interaction forces of binding on the CPU and GPU, in real-time, have been developed. The force calculation methods proposed here overcome several computational limitations of previous approaches, such as precomputed force grids, and could potentially be used to model molecular exibility at haptic refresh rates. Methods for force scaling, multipoint collision response, and haptic navigation are also reported that address newfound issues, particular to the interactive docking of large systems, e.g. force stability at molecular collision. The i ii result is a haptics-assisted docking application, Haptimol RD, that runs on relatively inexpensive consumer level hardware, (i.e. there is no need for specialized/proprietary hardware)

Advances in Human-Protein Interaction - Interactive and Immersive Molecular Simulations

International audienc

Six Degree-of Freedom Haptic Rendering for Dental Implantology Simulation

International audienceDental implantology procedures are among the most com- plex surgical procedures executed by dentists. During the critical part of the procedure, the jawbone is drilled at the location of the missing tooth (or the missing group of teeth). This asks for specic skills from the dentists, who need to be well trained. In this paper we present a virtual reality based training system for im- plantology and we mainly focus on the simulation of drilling. We have two main contributions: The rst one is a method for precise haptic rendering of contacts between the drilling tool and the jawbone model issued from a CT-scan. The second one is the real-time simulation of the jawbone erosion during drilling which is compatible with the haptic rendering of contacts

Ambient occlusion and shadows for molecular graphics

Computer based visualisations of molecules have been produced as early as the 1950s to aid researchers in their understanding of biomolecular structures. An important consideration for Molecular Graphics software is the ability to visualise the 3D structure of the molecule in a clear manner. Recent advancements in computer graphics have led to improved rendering capabilities of the visualisation tools. The capabilities of current shading languages allow the inclusion of advanced graphic effects such as ambient occlusion and shadows that greatly improve the comprehension of the 3D shapes of the molecules. This thesis focuses on finding improved solutions to the real time rendering of Molecular Graphics on modern day computers. The methods of calculating ambient occlusion and both hard and soft shadows are examined and implemented to give the user a more complete experience when navigating large molecular structures

Design and development of a VR system for exploration of medical data using haptic rendering and high quality visualization

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