The purpose of this study was to introduce and validate a new algorithm to estimate instantaneous aortic blood flow (ABF) by mathematical analysis of arterial blood pressure (ABP) waveforms. The algorithm is based on an autoregressive with exogenous input (ARX) model. We applied this algorithm to diastolic ABP waveforms to estimate the autoregressive model coefficients by requiring the estimate...

tients with neurotrauma. ANESTHESIOLOGY 2002; 96:595–9 21. Pfitzner J: Poiseuille and his law. Anaesthesia 1976; 31:273–5 22. Wang JJ, Flewitt JA, Shrive NG, Parker KH, Tyberg JV: Systemic venous circulation. Waves propagating on a windkessel: Relation of arterial and venous windkessel to systemic vascular resistance. Am J Physiol Heart Circ Physiol 2006; 290:H154–62 23. De Piccoli B, Rigo F, R...

The aorta, as the major conduit artery of the human body, is primarily thought of as a blood vessel that provides a low-resistance path for blood flow directed from the heart to peripheral organs and tissues. However, the aorta has another central hemodynamic function, whereby the elastic nature of the aortic wall provides a significant biomechanical buffering capacity complementing the pulsati...

Various detailed models of cerebral circulation have been proposed, recently fostered by the hypothesized relationship between extracranial venous drainage impairment and neurodegenerative diseases. However, some basic model is missing, analogous to 2-element Windkessel (WK) systemic circulation. This theoretical study focuses, in simplest way, on dependence intracranial pressure (VP) pulsatili...

The Windkessel model enlarges his applicativity on the whole circulatory dynamics studies. Then, the lumped parameter models allow global representation of blood flow circulation. In the vascular tree, peripheral branches are terminated by a resistance term representing smaller vessels. Blood flow and pressure are expressed by the intensity of current and voltage in an electrical analogue based...

A windkessel model was applied on a beat-to-beat basis to evaluate the arterial mechanical characteristics in seven conscious rats. Ascending aortic arterial pressure (AP) and blood flow were recorded during steady-state in basal conditions, during infusions of isoprenaline, sodium nitroprusside, and phenylephrine, and after intravenous atenolol injection. For each cardiac cycle the exponential...

Cardiac output (CO) and stroke volume (SV) are the key hemodynamic parameters to be monitored and assessed in ambulatory and critically ill patients. The purpose of this study was to introduce and validate a new algorithm to continuously estimate, within a proportionality constant, CO and SV by means of mathematical analysis of peripheral arterial blood pressure (ABP) waveforms. The algorithm c...