A delay recruitment model of the cardiovascular control system

Abstract

We develop a nonlinear delay-differential equation for the human cardiovascular control system, and use it to explore blood pressure and heart rate variability under short-term baroreflex control. The model incorporates an intrinsically stable heart rate in the absence of nervous control, and allows us to compare the baroreflex influence on heart rate and peripheral resistance. Analytical simplifications of the model allow a general investigation of the rôles played by gain and delay, and the effects of ageing.

The effects of performing isometric training at two exercise intensities in healthy young males

“…Research has shown that baroreflex control of resting BP occurs via modulation of sympathetic and parasympathetic nerve activity supplying the heart, and sympathetic innervation of the peripheral vasculature (Eckberg et al 1972;O'Leary and Seamans 1993;Fowler and McGuinness 2005). It was hypothesized that since MAP increases significantly during isometric exercise, repeated exposures to this pressor response may serve as a stimulus for baroreceptor resetting (Wiley et al 1992), presumably to a lower operating point (O'Leary 1996).…”

Confronting a cardiovascular system model with heart rate and blood pressure data

“…The heart and pulmonary system are effectively combined into one cardiac output term. We assume (i) a closed system with incompressible blood, thereby conserving blood volume, (ii) compliant arteries and veins, and (iii) the capillary system is like a resistance vessel [15].…”

“…The Hill function g(p) represents the pressuredependent baroreceptor control. The default values used by Fowler and McGuinness [15] were α = 1.3, β = 0.3, ε h = 0.18, ε p = 0.3, ν = 0.4, δ = 1, µ = 0.5, γ = 0.2, n = 3. The influence of respiration is controlled by the amplitudes A 1 and A 2 (dimensionless), frequency f r (s −1 ), and phase lag φ (dimensionless) of the response; we take φ = π.…”

Mathematical modeling and analysis of a cardiovascular system

“…This process is described in [1]. Mathematical modeling of this process leads to a system of differential equations with delay.…”