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

Abstract

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.

Keywords:

• Needle insertion
• Brain
• Finite element model
• Non-linear finite element procedures
• Subject-specific constitutive properties
• Hyperviscoelastic constitutive model

Acknowledgements

This research work has been supported by funds provided by the Australian Research Council (Linkage Grant No. LX0560460) and The University of Western Australia (UWA) 2005 Research Grant Scheme.

Notes

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Additional information

Notes on contributors

T. Washio

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