3D Cohesive Finite Element Minimum Invasive Surgery Simulation Based on Kelvin Voigt Model

Minimum Invasive Surgery is an important means of cytopathological examination. At present, there are few researches on three dimensional (3D) puncture simulation model base on suitable constitutive model, so a reasonable three dimensional puncture simulation model can reveal the internal deformation state of the tissue at the micro level. In this paper, a new viscoelastic constitutive equation suitable for muscle tissue and a method to define the fracture characteristics of muscle tissue material in the simulation process are proposed. The fracture of muscle tissue in contact with puncture needle is simulated by using the cohesive zone model, and a 3D puncture finite element model is established to analyze the deformation of muscle tissue. The stress nephogram and reaction force under different parameters were compared and analyzed to study the deformation of biological soft tissue, so as to guide the actual operation process and reduce pain.

Static Deflection Behavior of a Piezoelectric Forceps

A model is described for predicting quasi-static behavior of a piezoelectric forceps actuator (PFA), which consists of two slightly curved composite beams with bonded piezoelectric layers. The PFA is an innovative medical device that is potentially useful for minimum invasive surgery. The PFA model is compared to the deflection measurements made by a curvature sensor in experiments. This model, with a slight modification, can also be applied to other types of piezoelectric actuators with curved structural components.