Subject-specific non-linear biomechanical model of needle insertion into brain

• Published in: Computer methods in biomechanics and biomedical engineering Vol. 11; no. 2; p. 135
• Main Authors: Wittek, A, Dutta-Roy, T, Taylor, Z, Horton, A, Washio, T, Chinzei, K, Miller, K
• Format: Journal Article
• Language: English
• Published: England 01.04.2008
• Subjects: Biomechanical Phenomena - methods; Brain - physiology; Computer Simulation; Elasticity; Hardness; Humans; Models, Biological; Needles; Prosthesis Implantation - methods; Punctures - instrumentation; Punctures - methods; Stress, Mechanical; Viscosity
• ISSN: 1025-5842
• DOI: 10.1080/10255840802296665

The previous models for predicting the forces acting on a needle during insertion into very soft organs (such as, e.g. brain) relied on oversimplifying assumptions of linear elasticity and specific experimentally derived functions for determining needle-tissue interactions. In this contribution, we propose a more general approach in which the needle forces are determined directly from the equations of continuum mechanics using fully non-linear finite element procedures that account for large deformations (geometric non-linearity) and non-linear stress-strain relationship (material non-linearity) of soft tissues. We applied these procedures to model needle insertion into a swine brain using the constitutive properties determined from the experiments on tissue samples obtained from the same brain (i.e. the subject-specific constitutive properties were used). We focused on the insertion phase preceding puncture of the brain meninges and obtained a very accurate prediction of the needle force. This demonstrates the utility of non-linear finite element procedures in patient-specific modelling of needle insertion into soft organs such as, e.g. brain.