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Title: Efficient haptic and visual soft tissue deformation using a particle-based approach
Author: Buckley, Oliver
ISNI:       0000 0004 2681 183X
Awarding Body: Bangor University
Current Institution: Bangor University
Date of Award: 2009
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As the performance level of personal computers increases so does the desire for ever more realistic and immersive simulation experiences. An application area where high fidelity virtual environments are especially beneficial is that of medical procedures training simulation. In recent years there has been an increased desire to create more realistic and immersive training simulators to supplement traditional training methods. The latter relies heavily on fixed anatomy models, methods that use synthetic materials, to replicate specific training models and situations. The main problems with the use of fixed anatomy models is that they will degrade over time, they will not produce a consistent challenge and may only offer rigid training simulations that provide focus on a single area of training. The use of computer graphics and haptics technologies provides the opportunity to create a training experience that is both infinitely configurable and will not degrade over time. A large contributor to the fidelity of many medical procedure simulations is realistic soft object (anatomy) modelling. Existing methods usually make a trade off between performance and accuracy. For example the Finite Element Modelling approach will produce very accurate results but at a high computational cost, whereas the Mass Spring Model approach will produce less accurate but efficient and real-time results. Added to this the inclusion of haptic response, however, will increase further computational overheads. This thesis presents a particle-based approach to soft tissue modelling with force feedback that will run in real-time on a standard desktop PC and provide haptic feedback. To our knowledge this is the first particle-based approach that also supports haptics. This is achieved using a novel Charged Particles approach to control the haptic rendering. Particles are modelled as having an electromagnetic charge, and the Haptic Interaction Points, HIPs, are also modelled with the opposite electromagnetic charge. The system obeys the rules of electromagnetic interaction, and as a HIP gets closer to the soft tissue a repulsive force is generated to give the feeling of a continuous surface. The Charged Particles provide a relatively low-resolution haptic surface, and these points will act as control points for a high-resolution visual representation. This model also provides provision to cut or restructure the objects modelled, as well as being able to load generic model files. The resulting simulation is capable of running in real-time, both visually and haptically, on a low-end desktop machine at frame rates that compare favourably to existing methods.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available