Biomedical subjects

Yunhe Shen

Publications and source records attributed to Yunhe Shen.

3 recordsLinked to original sources

PubMed2006

Selective tessellation algorithm for modeling interactions between surgical instruments and tissues.

We present a selective spatial tessellation algorithm that is specifically optimized for instrument-to-tissue and instrument-to-instrument collision detection cases, which are the essential part of interaction modeling in surgery simulation with haptic feedback. Virtual surgeries demand haptic rate collision solutions only when instruments are involved in collisions. Other collision cases can be processed at slower rates. The proposed selective tessellation algorithm is capable of differentiating among various collision cases and assigning different priorities to their processing. Without making assumptions about any object movement, the algorithm derives clipping volume as collision detection regions which tightly enclose the objects of interest. Results of implementation of the algorithm in a surgical simulation are provided.

Algorithms↗

PubMed2006

Physically accurate mesh simulation in a laparoscopic hernia surgery simulator.

In this paper we use the 2D angular spring based mass-spring-damper (AMSD) model to simulate the plastic mesh in a laparoscopic hernia surgery simulator. We propose a physically based method to systematically derive the optimal parameters of the 2D AMSD model. While the traditional 2D MSD model lacks resistance against bending, the 2D AMSD model with optimized parameters can provide correct bending resistance as well as stretching resistance. The simulated mesh is demonstrated to be much more realistic.

Algorithms↗

PubMed2005

Haptic herniorrhaphy simulation with robust and fast collision detection algorithm.

Collision detection and soft tissue deformation are two major research challenges in real time VR based simulation, especially when haptic feedback is required. We have developed a real time collision detection algorithm for a prototype laparoscopic surgery trainer. However, this algorithm makes no assumptions about its applications and thus can be a generic solution to complicated collision detection problems. For soft tissue modeling, we use the mass-spring model enhanced with volume constraint and, stability control methods. We use both the new collision detection and tissue modeling algorithms in a bimanual hernia repair simulator which performs a mesh prosthesis stapling operation in real time.

Algorithms↗