Dynamic compressive response of bovine liver tissues

Area of Science:

• Biomechanical engineering
• Soft tissue mechanics
• Materials science

Background:

• Understanding the mechanical properties of biological tissues is crucial for medical device design and surgical planning.
• The strain rate-dependent behavior of soft tissues significantly influences their response to dynamic loading conditions.

Purpose of the Study:

• To experimentally determine the strain rate effects on the compressive stress-strain behavior of bovine liver tissue.
• To characterize the mechanical response of liver tissue across a wide range of strain rates.

Main Methods:

• Specimens of fresh bovine liver were subjected to compressive loading at quasi-static (0.01, 0.1 s⁻¹), intermediate (1, 10, 100 s⁻¹), and high (1000, 2000, 3000 s⁻¹) strain rates.
• High strain rate experiments utilized a modified Kolsky bar system with a hollow transmission bar and semiconductor strain gages.
• Quartz-crystal force transducers monitored testing validity.

Main Results:

• Bovine liver tissue displays a non-linear compressive stress-strain response.
• The tissue exhibits significant rate sensitivity, particularly at higher strain rates.
• Liver tissue stiffens considerably as strain rate increases.
• Mechanical responses were consistent along and perpendicular to the liver surface.

Conclusions:

• Bovine liver tissue is highly sensitive to strain rate in compression.
• The observed stiffening effect with increasing strain rate is a key characteristic of liver biomechanics.
• The isotropic nature of the tissue's mechanical response simplifies its modeling and application in biomechanical studies.