Title
A Physics-driven Neural Networks-based Simulation System (PhyNNeSS) for multimodal interactive virtual environments involving nonlinear deformable objects.
Abstract
BACKGROUND: While an update rate of 30 Hz is considered adequate for real time graphics, a much higher update rate of about 1 kHz is necessary for haptics. Physics-based modeling of deformable objects, especially when large nonlinear deformations and complex nonlinear material properties are involved, at these very high rates is one of the most challenging tasks in the development of real time simulation systems. While some specialized solutions exist, there is no general solution for arbitrary nonlinearities. METHODS: In this work we present PhyNNeSS - a Physics-driven Neural Networks-based Simulation System - to address this long-standing technical challenge. The first step is an off-line pre-computation step in which a database is generated by applying carefully prescribed displacements to each node of the finite element models of the deformable objects. In the next step, the data is condensed into a set of coefficients describing neurons of a Radial Basis Function network (RBFN). During real-time computation, these neural networks are used to reconstruct the deformation fields as well as the interaction forces. RESULTS: We present realistic simulation examples from interactive surgical simulation with real time force feedback. As an example, we have developed a deformable human stomach model and a Penrose-drain model used in the Fundamentals of Laparoscopic Surgery (FLS) training tool box. CONCLUSIONS: A unique computational modeling system has been developed that is capable of simulating the response of nonlinear deformable objects in real time. The method distinguishes itself from previous efforts in that a systematic physics-based pre-computational step allows training of neural networks which may be used in real time simulations. We show, through careful error analysis, that the scheme is scalable, with the accuracy being controlled by the number of neurons used in the simulation. PhyNNeSS has been integrated into SoFMIS (Software Framework for Multimodal Interactive Simulation) for general use.
Year
DOI
Venue
2011
10.1162/PRES_a_00054
Presence
Keywords
Field
DocType
neural network,interactive surgical simulation,multimodal interactive virtual environment,physics-driven neural,real-time simulation system,real-time computation,real-time force feedback,real-time graphics,real-time simulation,deformable human stomach model,deformable object,next step,nonlinear deformable object,bioinformatics,virtual environment,software framework,real time computing,real time,computer model,biomedical research,finite element model,force feedback,radial basis function network,multimodal interaction,material properties
Radial basis function network,Nonlinear system,Precomputation,Simulation,Computer science,Artificial neural network,Haptic technology,Software framework,Computation,Scalability
Journal
Volume
Issue
ISSN
20
4
1054-7460
Citations 
PageRank 
References 
3
0.41
33
Authors
4
Name
Order
Citations
PageRank
Suvranu De121934.31
Dhannanjay Deo230.41
Ganesh Sankaranarayanan317524.85
Venkata S. Arikatla4153.84