Suturing simulation based on complementarity constraints

This paper introduces a new method, based on complementarity constraints, for simulating virtual sutures in soft tissues. Complementarity constraints are known for the modeling of contacts with friction between solid objects, however they can be used for other types of interactions. We focus on modeling the physical nature of the interactions between a soft anatomical structure and a needle or surgical thread during a suturing task. In particular we model needle puncture through soft tissues, followed by the friction that occurs when sliding through the tissue, the cutting forces associated to different tissue layers, and the collision with boundary membranes. A common iterative solver is used for all constraints, in combination with an implicit integration scheme, providing fast and stable simulations even for complex scenarios.