Cynthia Bruyns

Real-time simulation of deformable objects: tools and application

Presents algorithms for animating deformable objects in real time. We focus on computing the deformation of an object subject to external forces and detecting collisions among deformable and rigid objects. The targeted application domain is surgical training. This application relies more on visual realism than exact, patient-specific deformation, but requires that computations be performed in real time. This is in contrast with pre-operative surgical planning, where computations may be done offline but must provide accurate results. To achieve real-time performance, the proposed algorithms take advantage of the fact that most deformations are local, human-body tissues are well damped, and motions of surgical instruments are relatively slow. They have been integrated into a virtual reality system for simulating the suturing of small blood vessels (microsurgery).

Interactive cutting of 3D surface meshes

Abstract Engineers and scientists from many fields are using three-dimensional reconstruction for visualization and analysis of physical and abstract data. Beyond observing the recreated objects in artificial space, it is desirable to develop methods that allow one to interactively manipulate and alter the geometry in an intuitive and efficient manner. In the case of medical data, a baseline interactive task would be to simulate cutting, removal and realignment of tissue. In order to provide for operational realism, the underlying mathematical calculations and topological changes need to be invisible to the user so that the user feels as though they are performing the task just as they would on the real world counterpart of the reconstructed object. We have developed a method that allows the user to directly sketch the desired cut contour on a three-dimensional surface in a manner that simulates dragging scissors through fabric. This new method can be employed interactively, allowing the user to perform the task in an intuitive, natural manner.

A virtual environment for simulated rat dissection: a case study of visualization for astronaut training

Animal dissection for the scientific examination of organ subsystems is a delicate procedure. Performing this procedure under the complex environment of microgravity presents additional challenges because of the limited training opportunities available that can recreate the altered gravity environment. Traditional astronaut crew training often occurs several months in advance of experimentation, provides limited realism, and involves complicated logistics. We have developed an interactive virtual environment that can simulate several common tasks performed during animal dissection. In this paper, we describe the imaging modality used to reconstruct the rat, provide an overview of the simulation environment and briefly discuss some of the techniques used to manipulate the virtual rat.

Virtual reality extensions into surgical training and teleoperation

Virtual reality simulation of surgery and scientific experiments help in preparation, training, and assessment. These benefits can be further extended with the integration of robotics for teleoperation and assistance. We describe our efforts to build a realistic and useable simulation for astronaut training and experiment planning. During development we focused on extending the simulation to real world interaction by adding registration and robotic components. Accurate registration, calibration, and robotic integration helped build a foundation for a useable simulation for astronaut training on ground and avenues of robotic assistance during flight.

Simulated Animal Dissection

We have developed a flexible, multi-user, remote-capable virtual environment system that can be used to simulate rat dissection training. This paper will discuss the technologies required to create a virtual environment for the simulation of a rat dissection procedure incorporating haptic feedback.