Global sensitivity analysis informed model reduction and selection applied to a Valsalva maneuver model

TL;DR

This paper introduces a novel global sensitivity analysis-based approach for model reduction and selection, applied to a cardiovascular model of the Valsalva maneuver, demonstrating the importance of including both aortic and carotid regions.

Contribution

It develops a new time-varying sensitivity analysis method called limited-memory SIs and applies it to optimize a physiological model for better accuracy and simplicity.

Findings

Both aortic and carotid regions are necessary for accurate modeling.

Limited-memory SIs effectively identify influential parameters over time.

Model selection favors including both regions based on information criteria.

Abstract

In this study, we develop a methodology for model reduction and selection informed by global sensitivity analysis (GSA) methods. We apply these techniques to a control model that takes systolic blood pressure and thoracic tissue pressure data as inputs and predicts heart rate in response to the Valsalva maneuver (VM). The study compares four GSA methods based on Sobol' indices (SIs) quantifying the parameter influence on the difference between the model output and the heart rate data. The GSA methods include standard scalar SIs determining the average parameter influence over the time interval studied and three time-varying methods analyzing how parameter influence changes over time. The time-varying methods include a new technique, termed limited-memory SIs, predicting parameter influence using a moving window approach. Using the limited-memory SIs, we perform model reduction and selection to analyze the necessity of modeling both the aortic and carotid baroreceptor regions in response to the VM. We compare the original model to three systematically reduced models including (i) the aortic and carotid regions, (ii) the aortic region only, and (iii) the carotid region only. Model selection is done quantitatively using the Akaike and Bayesian Information Criteria and qualitatively by comparing the neurological predictions. Results show that it is necessary to incorporate both the aortic and carotid regions to model the VM.