Physical basis of pressure transfer from periphery to aorta: a model-based study

Area of Science:

• Cardiovascular physiology
• Biomedical engineering
• Hemodynamics

Background:

• Accurate measurement of central aortic pressure is crucial for cardiovascular health assessment.
• Current methods often require invasive procedures.
• Non-invasive techniques are highly desirable for routine clinical use.

Purpose of the Study:

• To develop and validate a novel time-domain method for deriving central aortic pressure from peripheral pressure and velocity measurements.
• To assess the accuracy of the method in reconstructing aortic pressure and wave shape.
• To investigate the influence of arterial properties on the derived pressure.

Main Methods:

• A time-domain approach was employed to separate peripheral pressure into forward and backward components.
• These components were time-shifted using a delay time (wave speed/distance) and recombined to reconstruct aortic pressure.
• The method was validated using a distributed model of the human systemic arterial tree, with data from carotid and brachial arteries.

Main Results:

• Aortic systolic and diastolic pressures were predicted with high accuracy (within 0.3-1.0 mmHg).
• Central aortic pressure wave shape was accurately reconstructed (RMSE: 1.07-1.56 mmHg).
• The pressure transfer function was found to depend on wave speed and reflection coefficients, with minimal dependence on vasoactive state.

Conclusions:

• Central aortic pressure and its transfer function can be accurately derived from peripheral pressure and velocity measurements using the proposed time-domain method.
• This technique offers a promising non-invasive alternative for assessing central hemodynamics.
• The method's robustness to changes in vasoactive state suggests clinical applicability.