background: with increasing age, some changes appeared in specifications of vessels which including dimensions and elasticity in their. the changes in parameters such as resistance, inertance and compliance vessels appear and eventually changes in the environmental pulse releases are in circulation. these changes clearly appear in specification of photoplethysmogram particularly in the size and...

This paper describes system analyze of the Windkessel models. The equations, space state and transfer functions of 2, 3 and 4 elements Windkessel models are described. The Simulink environment model schemas are presented as well. The Bode frequency and step response analyses are presented for all three models as well. Moreover the simulation of the special input signal which represents blood fl...

BACKGROUND With increasing age, some changes appeared in specifications of vessels which including dimensions and elasticity in theirs. The changes in parameters such as resistance, inertance and compliance vessels appear and eventually changes in the environmental pulse releases are in circulation. These changes clearly appear in specification of photoplethysmogram particularly in the size and...

Right ventricular (RV) afterload is commonly defined as pulmonary vascular resistance, but this does not reflect the afterload to pulsatile flow. The purpose of this study was to quantify RV afterload more completely in patients with and without pulmonary hypertension (PH) using a three-element windkessel model. The model consists of peripheral resistance (R), pulmonary arterial compliance (C),...

Windkessel and similar lumped models are often used to represent blood flow and pressure in systemic arteries. The windkessel model was originally developed by Stephen Hales (1733) and Otto Frank (1899) who used it to describe blood flow in the heart. In this paper we start with the onedimensional axisymmetric Navier-Stokes equations for time-dependent blood flow in a rigid vessel to derive lum...

OBJECTIVES Prosthetic replacement of the thoracic aorta with common Dacron prostheses impairs the aortic 'windkessel' and, in valve-sparing procedures, also aortic valve function. Elastic graft material may overcome these deficiencies. METHODS Fresh porcine aortas including the root were set up in a mock circulation before and after replacement of the ascending part with a novel vascular pros...

Proper interpretation of BOLD fMRI and other common functional imaging methods requires an understanding of neurovascular coupling. We used laser speckle-contrast optical imaging to measure blood-flow responses in rat somatosensory cortex elicited by brief (2 s) forepaw stimulation. Results show a large increase in local blood flow speed followed by an undershoot and possible late-time oscillat...

A simplified model of arterial blood pressure intended for use in model-based signal processing applications is presented. The main idea is to decompose the pressure into two components: a travelling wave which describes the fast propagation phenomena predominating during the systolic phase and a windkessel flow that represents the slow phenomena during the diastolic phase. Instead of decomposi...

3 Modelling 5 3.1 Elements of fluid mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.2 Flow in blood vessels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.3 Flow on a vessel graph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.4 One-dimensional analysis . . . . . . . . . . . . . . . . ....