Frequency and time dependent viscoelastic characterization of pediatric porcine brain tissue in compression

Area of Science:

• Biomechanical Engineering
• Pediatric Traumatology
• Materials Science

Background:

• Understanding pediatric brain tissue mechanics is vital for accurate head injury simulations.
• Limited data on pediatric brain tissue viscoelasticity hinders the biofidelity of computational models.
• Characterizing these properties is essential for developing effective pediatric head protection.

Purpose of the Study:

• To investigate the viscoelastic behavior of pediatric porcine brain tissue under compression.
• To determine frequency-dependent and time-dependent viscoelastic properties.
• To identify suitable constitutive models for pediatric brain tissue.

Main Methods:

• Dynamic mechanical analysis was used to assess frequency-dependent properties (0.1–40 Hz).
• Compression tests and stress relaxation were performed at varying strain rates (0.01/s, 1/s, 10/s) up to 0.3 strain.
• Pediatric porcine brain tissue was utilized for experimental characterization.

Main Results:

• The loss modulus increased continuously above 20 Hz, while the storage modulus plateaued.
• Increasing strain rate significantly elevated mean stress at different strain levels (0.1, 0.2, 0.3).
• Pediatric brain tissue's compressive response demonstrated sensitivity to both strain rate and frequency.

Conclusions:

• The characterized viscoelastic properties offer valuable insights into pediatric brain injury mechanisms.
• This data is crucial for enhancing the biofidelity of computational models for pediatric head injuries.
• Findings will aid in the development of advanced head protection systems for children.