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Endovascular neurosurgery has gained acceptance as the best method of treatment of vascular abnormalities like cerebral aneurysms. However, the procedure is associated with difficulties in tool/tissue manipulation. Navigation of stent, catheter and, guide wire through complex arteries without any force information often causes stent snagging, plaque dislocations and formation of thrombosis caused by the damage of the arterial wall. Currently, there is no haptic device available which can provide the surgeons with the force information, related to stent placement procedure. The goal of this work is to create a data base for a fast synthetic endovascular force simulator, which will provide the surgeon with force information during tool-artery interaction, based on the various combinations of tool sizes and vessel complexity, [1, 2] to facilitate better preoperative planning, safer interventions, and advanced training of new surgeons.

Realistic trocar insertion simulator requires reliable and reproducible tissue data. This paper looks at using synthetic surrogate tissue to facilitate creation of data covering a wide range of pathological cases. Furthermore, we propose to map the synthetic puncture force data to the puncture force data obtained on animal/human tissue to create a simulation model of the procedure. We have developed an experimental setup to collect data from surrogate synthetic tissue using a bladeless trocar.

Subsurface modeling of deformable objects, such as soft tissues and organs, involves the use of non-destructive methods of determining the properties of an object encased by a material. Some of the properties that can be determined from subsurface modeling include: shape, hardness, texture and possibly material. The ability to determine these properties is based on the accuracy of the method used and the properties of the surface encasing the object. As computers become more powerful and are able to produce even more realistic graphics, it will be possible to store and re-create precise duplicates of the original for later analysis. This paper will present a method of approximately modeling both the surface and an object below the surface of the skin by a method of palpation and then present this data in an interactive 3-D model.

This paper describes our efforts at creating a system with real time acquisition and geometric processing of the patients vascular anatomy, supplemented by a framework to simulate catheter vasculature interaction. Our system uses biplane angiograms coupled with an algorithm for generation of 3D vascular trees for patient data acquisition. Surface reconstruction and processing of this data is performed to provide novel decision aids to the interventionalist. The processed data can be loaded in a virtual environment to simulate guidance of the catheter through the patient's vasculature. With our combination of techniques, a patient specific visualization and simulation environment can be prepared within the narrow time window available for this procedure.

The aim of computer haptics is to enable the user to touch, feel and maneuver virtual objects using a haptic interface. As the user "feels" the virtual object by applying force through the interface, complex calculations have to be done in real-time to generate a feedback force appropriate to the material properties of the object being "touched". In this paper we propose a method for modeling soft bodies, which incorporate non-linear, viscoelastic, anisotropic behavior that will enable real-time user interaction and still satisfy the high force-feedback frequency requirements. In this paper, we restrict the user interaction with virtual objects to palpation.