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Biomedical subjects

Suvranu De

Publications and source records attributed to Suvranu De.

6 recordsLinked to original sources
PubMed2006

Use of surgical videos for realistic simulation of surgical procedures.

One of the major challenges in the development of virtual environments for medical simulations is photorealistic rendering, permitting high fidelity visual effects and user interaction. Digitized videos recorded from the laparoscopic camera are a rich source of information about surgical scenarios. How to fully utilize the information is important for improving the realism of the simulated scenarios. In reality, the camera viewpoint changes frequently and even for the same viewpoint, the scene is dynamic due to rhythmic heartbeat. Hence, the results of classical texture mapping are usually visually unappealing as they fail to capture the pulsatile effect, as well as other global illumination properties of the scene. In this paper we present a hybrid technique to improve the photorealistic rendering of the virtual surgery scenarios by spatio-temporally utilizing videos recorded during actual surgical procedures.

Computer Simulation↗
PubMed2006

Measurement of the mechanical response of intra-abdominal organs of fresh human cadavers for use in surgical simulation.

Determination of soft tissue properties is essential for the realism of the virtual scenarios. The major challenge is that soft tissues exhibit complicated mechanical properties including viscoelastic, nonlinear, inhomogeneous, and rate dependent behaviors. Measurements on live human patients present significant risks, thus making the use of cadavers a logical alternative. Cadavers are widely used in present day surgical training, are relatively easy to procure through excellent donor programs and have the right anatomy, which makes them better candidates for training than the porcine model. To investigate the static and dynamic properties of soft tissue, we have developed a high precision tactile stimulator by modifying an existing haptic interface device, the Phantom, and used it to record the force-displacement behavior of intra-abdominal organs of fresh human cadavers at the US Surgical facility in Connecticut and Albany Medical College.

Abdomen↗
PubMed2005

Improving the visual realism of virtual surgery.

In this work we focus our attention on improving the visual realism of virtual surgery. A synthetic solution by innovative use of various image-based rendering methods is presented for realistic rendering of virtual surgery scenes. We have, for the first time, developed a methodology for generating virtual surgery scenes with realistic glistening effects by a combination of various image-based rendering techniques, including image mosaicing and view-dependent texture mapping. Realistic examples are presented to showcase the results.

Computer Simulation↗
PubMed2005

Improved virtual surgical cutting based on physical experiments.

Simulation of surgical cutting is one of the most challenging tasks in the development of a surgery simulator. Changes in topology during simulation make any precomputed data meaningless. Moreover, the process is nonlinear and given the complexity of soft tissue mechanics, the underlying physics is not well understood. Therefore, fully realistic procedures for the simulation of surgical cutting at real time rates on single processor machines is possibly out of reach. We developed a geometry-based algorithm that is capable of simulating progressive cutting without increasing the number of primitives and have coupled it to a meshfree physically based simulation scheme. In this paper we enhance a geometrically efficient cutting algorithm by including physical information from actual cutting experiments.

Algorithms↗
PubMed2004

Realistic simulation of surgical cutting of soft tissues in real time with force feedback.

In this paper we present a geometrically efficient algorithm coupled with a physically based numerical scheme using a meshfree approach for the simulation of surgical procedures including surgical cutting in multimodal virtual environments. Progressive cutting, without the generation of new primitives, is achieved by snapping the nearest nodes to the interaction point between the cutting tool and the underlying polygon edge. The realism of the simulations is enhanced by employing a local subdivision algorithm in the vicinity of the tool-tissue interaction region and a cutting gutter to display the interior structure of the soft tissue as the cut opens up. A meshfree method is used to compute the deformation fields and interaction forces.

Algorithms↗