Investigation of biological tissue cutting for minimal tissue damage using finite element simulation

In surgical cutting procedures for biological soft tissues, it is crucial to minimize tissue damage. However, before cut initiation, tissues undergo significant deformation due to their elastomeric properties. This deformation can cause tissue damage and increase the risk of complications, particularly in neurosurgery and ophthalmic surgery. The cut-initiation ability of a process must be improved to reduce the depth of the blade indentation required for cut initiation. Adding a slicing motion to the blade indentation has been found to enhance the cut initiation; however, the specific advantages of this method over pure indentation are not fully understood. This study aims to analyze the effects of cutting parameters, including blade motion, on the initiation of cuts in elastomeric solids, such as biological soft tissues, by examining the strain states beneath the blade that trigger cut initiation. During cutting, deep indentation by a sharp blade causes significant geometric nonlinearity, displacing the workpiece surface along the blade surface. These blade–workpiece interfacial interactions likely affect the strain states beneath the blade. Therefore, this study uses finite element simulations to examine the blade–workpiece interfacial interactions and their relation to the strain states, focusing on the influence of interfacial friction. The results indicate that the distribution of in-plane stretch along the blade surface of the workpiece is crucial for determining the strain states and the resulting cut-initiation ability. The improved cut initiation achieved by introducing a slicing motion to blade indentation can be attributed to the enhanced distribution of in-plane surface stretch.