A new model-based method of reconstructing central aortic pressure from peripheral arterial pressure

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology
• Medical Imaging

Background:

• The transfer function between central aortic and radial arterial pressure can be modeled using an elastic tube and Windkessel.
• Previous work suggests central pressure reconstruction by summing time-shifted forward and backward pressure waves.

Purpose of the Study:

• To test the hypothesis that central pressure can be reconstructed by adding time-shifted forward and backward pressure components derived from a model.
• To evaluate a model-based method for central pressure reconstruction against the generalized transfer function method.

Main Methods:

• Simultaneous measurement of central micromanometric and radial arterial tonometric pressure in eight patients.
• Estimation of radial arterial flow by imposing tonometric pressure to a modified Windkessel model.
• Separation of tonometric pressure into forward and backward components, followed by time-shifting and summation for central pressure reconstruction.

Main Results:

• Initial correlation between tonometric and central pressure was poor (r(2) 0.264–0.765).
• Both generalized transfer function (0.887–0.974) and model-based methods (0.849–0.979) significantly improved this correlation.
• Sensitivity analysis identified transmission delay as the critical parameter for central pressure reconstruction.

Conclusions:

• The model-based method accurately reconstructs central pressure, comparable to the generalized transfer function method.
• Individualizing the transmission delay allows for personalized transfer function estimation.
• This approach offers a precise and adaptable method for non-invasive central pressure assessment.