Delay-Dependent Output-Feedback Control for Blood Pressure Regulation Using LPV Techniques

TL;DR

This paper develops a delay-dependent LPV control method for automated blood pressure regulation, effectively handling time-varying delays and parameters to maintain stable MAP levels in critical care scenarios.

Contribution

It introduces a novel LPV-based output-feedback control design using LMIs for blood pressure regulation with delay considerations, improving stability and tracking performance.

Findings

Effective MAP regulation in simulations

Robustness to parameter variations

Smooth drug injection achieved

Abstract

This paper presents a delay-dependent parameter-varying control design approach to address the automated blood pressure regulation problem in the critical patient resuscitation using closed-loop administration of vasopressors. The mean arterial pressure (MAP) response of a patient subject to the intravenous vasoactive drug treatment is modeled as a linear parameter-varying (LPV) model, where varying model parameters and varying time-delay are considered as scheduling parameters of the system. Parameter-dependent Lyapunov-Krasovskii functionals are used to design an output-feedback dynamic controller to satisfy the closed-loop stability and reference MAP tracking requirements. The synthesis conditions are formulated in terms of Linear Matrix Inequalities (LMIs) that characterize the induced $\mathcal{L}_2$-norm performance specification of the closed-loop system. The main objectives of the proposed control method in the presence of limitations posed by the time-varying model parameters and the large time-varying delay are to track the MAP reference command and maintain the blood pressure within the permissible range of commanded set-point, avoid undesirable overshoot and slow response, and to provide a smooth drug injection. Finally, to evaluate the performance of the proposed LPV blood pressure regulation approach, closed-loop simulations are conducted and the results confirm the effectiveness of the proposed control method against various simulated scenarios.