A Novel Method for Cardiac Output and Vascular Parameters Estimation Using Peripheral Arterial Waveforms: Integrating...

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Medical Device Technology

Background:

• Conventional cardiac output (CO) estimation methods often lack physiological interpretability and generalizability due to reliance on calibration or black-box models.
• Accurate and interpretable CO monitoring is crucial for effective perioperative and critical care management.

Purpose of the Study:

• To develop and validate a structurally identifiable model for simultaneous estimation of CO and vascular parameters from peripheral arterial pressure waveforms.
• To provide a physiologically interpretable, data-efficient, and calibration-free alternative to existing CO estimation techniques.

Main Methods:

• A four-element Windkessel model was reformulated using alpha-parameters (αC, αR, αL, ατ) to represent arterial properties.
• Peripheral arterial pressure waveforms were processed and fitted to the model to extract alpha-parameters, which then informed a generalized linear model for CO estimation.
• Estimated CO was used to derive arterial compliance (C), characteristic impedance (Rz), distal resistance (Rdis), and inertance (L).

Main Results:

• Internal validation demonstrated R²=0.82 and percentage error (PE)=26.17%, meeting clinical interchangeability criteria (PE < 30%).
• External validation on an independent dataset yielded R²=0.72 and PE=28.41% without retraining, confirming model robustness.
• The model successfully estimated CO and key vascular parameters (C, Rz, Rdis, L) with high accuracy and consistency.

Conclusions:

• The alpha-parameterized Windkessel framework offers a physiologically grounded, calibration-free approach for CO estimation.
• This method simultaneously quantifies multiple hemodynamic parameters, providing a comprehensive profile from a single arterial pressure signal.
• The framework is suitable for real-time integration into critical care monitoring systems, enhancing patient management.