Modelling and simulation of impact waves in brain matter

Project Information

TBI-WAVES

Grant agreement ID: 101023950

DOI

10.3030/101023950

Project closed

EC signature date 22 March 2021

Start date 1 October 2021

End date 30 September 2023

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 184 590,72

EU contribution

€ 184 590,72

Coordinated by

UNIVERSITY OF GALWAY
Ireland

Periodic Reporting for period 1 - TBI-WAVES (Modelling and simulation of impact waves in brain matter)

Reporting period: 2021-10-01 to 2023-09-30

Summary of the context and overall objectives of the project

The past decade has seen the emergence of numerous studies aimed at understanding the function of the brain and its behaviour. An important challenge lies in the prediction and the treatment of Traumatic Brain Injury (TBI), which is a major source of death and disability with huge human and financial costs. Using mechanics, consequential efforts have been dedicated to the mathematical description of the response of brain matter to forces. Huge resources have also been invested in the computer simulation of head injury scenarios. Further progress in these directions is of utmost importance to biomedical engineering, forensic science, and medicine, where numerical simulation is used to design new products and surgery techniques, and to understand the brain’s evolution after trauma.

Experimental results suggest that head trauma could be linked to the development of shear shock waves in the brain, or to the focusing of shear waves at the centre of the brain. To better understand the mechanical processes behind brain damage, further research in this area is needed. To this end, precise knowledge of the mechanical response of brain tissue to dynamic loading is a key prerequisite. Reaching this goal requires in-depth study of wave propagation in soft solids.

In this context, the TBI-WAVES project aimed at improving the mechanical and computational models of brain tissue, by
• studying the influence of the fluid content on the motion of brain tissue based on the theory of porous media
• investigating the mechanical causes of brain damage by following the phenomenology of TBI
• developing advanced numerical methods for wave propagation simulations in brain matter
These steps will pave the way towards the development of a high-performance computational framework for the simulation of head trauma.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The main results of the TBI-WAVES project are new mathematical and computational models that predict the mechanical response of brain tissue under dynamic loading. I developed
• wave equations that describe the propagation of nonlinear shear waves in soft viscous tissues
• exact nonlinear wave solutions that travel at constant speed in viscoelastic soft tissues
• fractional and anisotropic viscoelastic models for soft tissues that predict the evolution of the shear wave speed with applied pre-stress
• computer simulations of the torsion of soft porous media
• a computational method that predicts the propagation of nonlinear shear waves in soft viscoelastic tissues

I contributed six journal papers: one published in the Journal of the Acoustical Society of America, one published in the European Journal of Mechanics - A/Solids, and four other manuscript that are currently undergoing peer-review in various scientific journals. All are high impact factor journals in Acoustics, Applied Mathematics, and Engineering. I also co-organized a mini-symposium on nonlinear waves at the 11th European Solid Mechanics Conference (July 2022), one of the major conferences in mechanics.

I disseminated my results at several international conferences:
• 10th International Congress on Industrial and Applied Mathematics, August 2023, Tokyo (Japan)
• 15th International Conference on Mathematical and Numerical Aspects of Wave Propagation, July 2022, Palaiseau (France)
• International Workshop on The Evolving Nonlinear Continuum Panorama, July 2022, Castro Urdiales (Spain)
• 11th European Solid Mechanics Conference, July 2022, Galway (Ireland)

To further communicate my research results to a wider audience, I delivered several talks and seminars and participated in the following outreach activities:
• Bright Club Ireland, November 2022, with a 9-minute talk entitled “Here comes the sound”
• I’m a Mathematician Ireland, October 2022, whose online forum allowed me to answer questions by Irish primary school students

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The TBI-WAVES project addresses a global health issue (UN Sustainable Development Goal 3), whose understanding is a key for a better future. In addition, through outreach, the project has raised awareness of the importance of mathematics teaching and research in our society.

The proposed mathematical and computational models of brain tissue will be of great use for the analysis and simulation of head trauma, safety devices, protective gear, and surgery techniques. Based on the project’s results, ongoing and future works will contribute to the development of high-performance computational frameworks for the simulation of head trauma.

We note in passing that the study of wave propagation in soft solids has found many applications beyond brain mechanics. Therefore, other sectors could benefit from the project outcomes. For instance, the simulation of material testing techniques and medical imaging problems (echography, tomography, elastography, etc.) could benefit from the proposed models and computer methods.

Wave propagation in brain tissue: theory and simulations