Assessing the mechanical properties of anisotropic soft tissues using guided wave elastography: Inverse method and...

Area of Science:

• Biomechanics
• Materials Science
• Medical Imaging

Background:

• Determining the mechanical properties of soft biological tissues is crucial for understanding their function and pathology.
• Many soft tissues, like the human Achilles tendon, exhibit anisotropic material behavior due to their microstructure.
• Accurate characterization of tissue mechanics is essential for medical diagnostics and treatment planning.

Purpose of the Study:

• To propose and validate an inverse approach using guided wave elastography for determining anisotropic elastic and hyperelastic parameters.
• To characterize thin-walled, transversely isotropic biological soft tissues.
• To assess the accuracy and sensitivity of the proposed method to data errors.

Main Methods:

• Development of an inverse approach based on theoretical solutions for guided wave dispersion relations.
• Utilizing a constitutive model tailored for the deformation behavior of anisotropic soft tissues.
• Incorporating the condition number to evaluate sensitivity to data errors.
• Validation through numerical experiments of guided wave elastography on simulated tissues.

Main Results:

• The proposed inverse approach successfully determines anisotropic elastic and hyperelastic parameters.
• Four constitutive parameters, excluding the tensile modulus along the fiber direction (E_L), were identified with good accuracy.
• The method's robustness to data errors was investigated using the condition number.

Conclusions:

• Guided wave elastography offers a viable method for characterizing anisotropic mechanical properties of soft biological tissues.
• The developed inverse approach provides accurate determination of key constitutive parameters.
• This technique holds promise for non-invasive assessment of tissue mechanics in clinical applications.