A hyperelastic-plastic damage model for puncture analysis of tympanic membrane using finite-element method.

The puncture and damage behaviour of the tympanic membrane (TM) during needle insertion, a common procedure for accessing the middle and inner ear, is critical for advancing treatments for hearing and balance disorders. This study presents a novel 3D finite-element (FE) model of TM puncture, capturing both the geometric complexity of the needle and the middle ear and the nonlinear material properties of the TM, including its high-strain deformation, damage accumulation, and crack propagation. By calibrating damage-related mechanical properties, including fracture strain and yield stress, the presented model accurately replicated experimental puncture forces (2.6% error) and predicted a maximum von Mises stress of 1.0 MPa at the puncture instance. The model also enabled analysis of the effects of insertion location, needle inclination, needle tip geometry, and TM thickness on puncture force. Additionally, it allowed for the evaluation of both axial and lateral forces, offering insights for the development of haptic devices, surgical robots, and virtual-reality medical training systems.