Biomechanical Finite Element Simulation of Cochlear Implant Surgical Robot Drilling Through Direct Cochlear Access

Robotic drilling through direct cochlear access for cochlear implantation (CI) is currently a prominent area in the field of CI surgery. However, the safety of drilling remains an issue due to the limited space within the facial recess. Estimation and control of drilling force are critical to prevent drill-bit breakthrough, excessive heat generation, and mechanical damage to the facial nerve. The bone drilling process presents a favorable application scenario for finite element (FE) analysis. In this study, a 3D FE model of temporal bone drilling is established for the first time to predict the drilling force. The self-developed CI surgical robot validates these findings through experimental drilling. The experimental results show that the drilling process can be divided into three stages, and the corresponding force curve can be divided into six zones. The overall trend of temporal bone drilling is two force peaks and one trough in the middle. The drilling force is positively correlated with the feed rate. The FE results found to be in good agreement with the experimental results. Numerical simulation can be utilized as an invaluable tool for assisting in predicting the position of drilling tools and optimizing drilling parameters in the future.