Cycle-Averaged Models of Cardiovascular Dynamics

Abstract Time-varying ventricular elastance models have been used extensively in the past to simulate the pulsatile nature of cardiovascular waveforms. Frequently, however, one is interested in dynamics that occur over longer timescales in which case a detailed simulation of each cardiac contraction becomes computationally burdensome. In this paper, we apply circuit-averaging techniques to a simplified lumped-parameter model of the cardiovascular system. The resultant cycle-averaged model is linear and time invariant, and greatly reduces the computational burden. It is also amenable to systemic order reduction methods that lead to further efficiencies. Despite its simplicity, the averaged model captures the dynamics relevant to the representation of a range of cardiovascular reflex mechanisms.