Biomedical subjects

Matthias Teschner

Publications and source records attributed to Matthias Teschner.

4 recordsLinked to original sources

PubMed2004

Interactive blood simulation for virtual surgery based on smoothed particle hydrodynamics.

In this paper, we propose an interactive method based on Smoothed Particle Hydrodynamics (SPH) to simulate blood as a fluid with free surfaces. While SPH was originally designed to simulate astronomical objects, we gear the method towards fluid simulation by deriving the force density fields directly from the Navier-Stokes equation and by adding a term to model surface tension effects. In contrast to Eulerian grid-based approaches, the particle-based approach makes mass conservation equations and convection terms dispensable which reduces the complexity of the simulation. In addition, the particles can directly be used to render the surface of the fluid. Our method can be used in interactive surgical training systems with models of up to 3000 particles.

Aneurysm↗

PubMed2004

Collision handling of deformable anatomical models for real-time surgery simulation.

Efficient collision handling of dynamically deforming anatomical models is a very challenging problem in real-time surgery simulation. In this paper, we present a new, efficient approach that detects collisions and self-collisions of deformable models. Our algorithm is integrated in a simulation framework for multiple interacting objects. This framework consists of three components. The first one computes the dynamic behavior of deformable structures using an efficient and robust approach with distance- and volume-preserving constraints. The second component detects collisions and self-collisions of deformable models. A novel image-space technique is employed that detects volumetric intersections. This allows to compute the penetration depth which is used to resolve collisions in the third component of our framework. Our system handles volumetric deformable models of up to several thousand surface triangles and tetrahedra in real-time and can be used in surgical training systems.

Algorithms↗

PubMed2002

Estimation of soft-tissue model parameters using registered pre- and postoperative facial surface scans.

Computer-based techniques for the simulation of craniofacial surgical procedures and for the prediction of the surgical outcome have been shown to be very useful. However, the assessment of the accuracy of the simulated surgical outcome is difficult. In this paper, a technique is described which allows to compare the simulated surgical outcome and the actual surgical result. The simulated postoperative patient's appearance is compared to a second surface scan which is obtained postoperatively. The pre- and postoperative surface scans, which are different due to the surgery, are registered employing a robust registration method which minimizes distances of corresponding points. Parameters of the soft-tissue model can be adapted with respect to minimized differences of corresponding points of the simulated postoperative and the actual postoperative surface of a patient's face.

Artifacts↗

PubMed2001

Computer-aided 3-D simulation and prediction of craniofacial surgery: a new approach.

Background: In plastic and reconstructive craniofacial surgery, careful preoperative planning is essential. In complex cases of craniofacial synostosis, rapid prototyping models are used to simulate the surgery and reduce operating time. Recently, 3-D CT model surgery has been introduced for presurgical planning and prediction of the postoperative result. Objective: For simulation of craniofacial surgery a computer-based system was developed that allows visualization and manipulation of CT-data using computer graphics techniques. Surgical procedures in all areas of the bony skull can be performed interactively. Results: The case of a child with scaphocephalus is presented. Surgery is planned using the craniofacial surgery simulator described above. Conclusion: The computer-based interactive surgery simulation systems presented here allow precise visualization of craniofacial surgery. The accurate computer-aided 3-D simulation of bone displacements is also the prerequisite for transfer of the simulated surgery using a navigation system for surgery. Thus the preoperatively planned procedure could be transferred directly to the operating table. Copyright 2001 European Association for Cranio-Maxillofacial Surgery.

Journal Article↗