THE FRICTIONAL CONTACT ANALYSIS BETWEEN A TACTILE SENSOR AND ATRIAL TISSUE IN VISCOELASTICITY

摘要

This paper discusses the effect of friction in tool–tissue interaction of surgical simulation. The focus of this research is on mitral valve repair by robot-assisted surgery (RAS) method with tactile feedback. Heart tissue is considered to be touched by a tactile sensor with considering the friction effect. A regularized Coulomb law analogous to elastoplastic theory is used to represent the friction. Since the heart tissue is subjected to repeated loading condition, a generalized standard solid chain is chosen for modeling the heart tissue. To implement the generalized standard solid chain in finite element analysis (FEA), a new splitting strategy is presented. The splitting strategy avoids the complicated conversion procedure from creep function to relaxation function by dividing the total problem into several subproblems. The penalty method is used in the derivation of continuum model for the interaction between the tactile sensor and the tissue. By performing linearization for the continuum model, the discrete model for the FEA is obtained. Numerical results are obtained by using the constitutive parameters of tissue and friction coefficient, which were found experimentally.