Noninvasive estimation of central blood pressure through fluid-structure interaction modeling

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology
• Computational Fluid Dynamics

Background:

• Central blood pressure (cBP) is a better cardiovascular health indicator than brachial blood pressure (bBP).
• Brachial blood pressure (bBP) overestimates cBP due to pulse wave amplification during propagation.
• Accurate cBP estimation is crucial for cardiovascular risk assessment.

Purpose of the Study:

• To develop an individualized transfer function for estimating central blood pressure (cBP) from brachial blood pressure (bBP).
• To enhance understanding of the physical mechanisms underlying pulse wave amplification and cBP estimation.

Main Methods:

• Constructed patient-specific 3D models of the upper limb arterial system using fluid-structure interaction simulations.
• Incorporated variable material properties and complex boundary conditions into the models.
• Developed an analytical brachial-aortic transfer function validated against numerical simulations.

Main Results:

• The transfer function accurately estimated cBP from bBP, reproducing pulse wave propagation and amplification.
• Central blood pressure (cBP) was found to be a linear combination of bBP and aortic flow rate in the frequency domain.
• Lumen radius was identified as the most influential parameter for accurate cBP estimation.

Conclusions:

• The developed transfer function improves understanding of the physics of pulse wave dynamics.
• Aortic flow rate and lumen radius are critical factors for accurate central blood pressure estimation.
• The findings can guide the development of more clinically applicable transfer functions for cBP measurement.