A Novel Method for Quantifying Human In Situ Whole Brain Deformation under Rotational Loading Using Sonomicrometry

Area of Science:

• Biomechanics
• Neuroscience
• Medical Imaging

Background:

• Traumatic brain injuries (TBI) are poorly understood.
• Existing finite element (FE) models for concussion research lack sufficient experimental validation data.
• Accurate brain deformation data is needed to improve TBI models and develop mitigation strategies.

Purpose of the Study:

• To develop and demonstrate a methodology for measuring in situ 3D brain deformation.
• To utilize sonomicrometry for capturing dynamic brain movement under pure rotational head loading.
• To provide experimental data for the validation of computational TBI models.

Main Methods:

• A human cadaveric head-neck specimen was instrumented with 32 sonomicrometry crystals (24 in the brain, 8 on the skull).
• The head was subjected to dynamic pure rotational loading using a closed-loop test device.
• Sonomicrometry was used to measure dynamic distances between crystals, capturing 3D brain deformation.

Main Results:

• The combined experimental and sonomicrometry approach reliably captured 3D dynamic brain deformation.
• The methodology demonstrated repeatability in measuring deformation across different rotational severities and axes.
• The study successfully acquired multidimensional experimental data of an intact human brain's deformation.

Conclusions:

• Sonomicrometry provides a viable framework for acquiring essential experimental data for FE model development and validation.
• The developed methods offer insights into the complex deformations the brain undergoes during impact.
• This research advances the understanding of TBI mechanics and supports the creation of more accurate predictive models.