An inverse fitting strategy to determine the constrained mixture model parameters: application in patient-specific...

Area of Science:

• Biomechanics and Mechanobiology
• Computational Solid Mechanics
• Biomaterials Science

Background:

• The Constrained Mixture Model (CMM) offers a framework for arterial wall mechanics based on a reference physiological state.
• Existing CMM applications have limited exploration of patient-specific modeling using experimental data.
• Arterial wall is viewed as a mixture of constituents with distinct mass fractions, material properties, and deposition stretches.

Purpose of the Study:

• To develop and validate an iterative numerical-experimental procedure for fitting the CMM to experimental data.
• To determine patient-specific material parameters and deposition stretch values for arterial wall constituents.
• To establish a link between CMM parameters and experimentally measurable residual strains.

Main Methods:

• Implementation of the CMM within a finite element framework.
• Development of an iterative fitting procedure combining numerical simulations and experimental data.
• Calibration of the model using reported experimental data from the descending thoracic aorta.

Main Results:

• Successful determination of material parameters for each constituent of the arterial wall.
• Numerical proof of a relationship between deposition stretches and residual strain measurements (opening angle, axial stretch).
• Demonstration of strong consistency between the CMM predictions and experimental data.

Conclusions:

• The proposed iterative numerical-experimental procedure effectively calibrates the CMM for arterial wall mechanics.
• The study establishes a robust link between the CMM's deposition stretches and experimentally observed residual strains.
• This approach enhances the potential for patient-specific modeling of arterial biomechanics.