LS-DYNA Simulation of in vivo Surgical Robot Mobility

In vivo surgical robot wheels were studied to develop a better wheel design using finite element analysis. A liver material model, derived from component testing, was implemented as a viscoelastic material. LS-DYNA simulation of this testing confirmed the accuracy of the liver material model. This material model was then used as the tissue model to study wheel performance. A helical wheel moving on the liver model was used to replicate laboratory experiments. Drawbar forces required to move the wheel across the liver for various slip ratios produced in simulation showed good agreement with the physical tests. The wheel design was then adjusted in the simulation to study how changes in the wheel diameter and the pitch of the helical tread affected the drawbar force. Results showed that an increased diameter and decreased pitch angle increased drawbar force. These results will be used in future surgical robot wheel designs.