The cardiovascular system and its short-term control: modelling and signal analysis

摘要: The function of the circulation is to supply tissues with oxygen, nutrients and remove carbon dioxide other catabolits. Variables involved in cardiovascular regulation, such as blood flow, pressure level, oxygen concentration, are kept around their reference point by several feedback control mechanisms. These mechanisms have different dynamics we interested only short term flow which assumed autonomic nervous system through baroreceptor loops. aim these lectures relate classical discrete-time signal analysis models systems taking into account its multiple loop organisation. Cardiovascular modelling leads us definition sensitivities pratical interest an approach for estimation blood-pressure/heart-beating-period baroreflex sensitivity. Models electro-mechanical activity cardiac muscle very useful at scale well organ scale. In this later case, they used computing stress, strain action potential fields from three-dimensional image processing. We present a chemically-controlled constitutive law myofibre mechanics devoted be embedded macroscopic models. This ensues collective behaviour actin-myosin molecular motors converting chemical mechanical energy. resulting sarcomeres consistent “sliding filament hypothesis” A. F. Huxley. 1 Physiological introduction 1.1 system: organs are: lungs allow gas exchanges, heart pumps vascular carries molecules tissues, see fig. (1). regulation exchanges under hemodynamic mechanisms, tend keep physiological variables level; adapt changes (orthostatisme exercise). A strict homeostasis view reduces complexity living regulation. illustrated (15). control, about few minutes, system, more precisely part (ANS). involves fast loop, neglecting slower ones, hormonal good crucial importance life great prognostic value many diseases.