CARDIOVASCULAR ENGINEERING Journal for Extracorporeal Circulation, Assist Devices,Transplantation and Artificial Organs
	Volume 3, 1998, No 1

Role and Relevancy of a Cardiovascular Simulator

P. Segers, F. Dubois, D. De Wachter, P. Verdonck

Abstract:
Background: We extended an existing pulse duplicator system of the human left heart with an elastic tube model of the arterial tree to a cardiovascular simulator. Methods: The arterial network model is made of natural latex rubber and includes the aorta, the upper and lower limb arteries, the carotid arteries and the major branches to the abdominal organs (kidneys, splanchnic tree, mesenterics). The 28 vascular beds terminating the arteries are modelled as adjustable resistances and air chambers (compliance) in parallel, allowing the simulation of physiological and pathological conditions. Results: Total arterial compliance for this specimen is 1.0 ml/mmHg, and total peripheral resistance 1.26 mmHg (ml/s). Flow distribution over the different vascular beds corresponds with in vivo data. Pressure is measured at six locations along the aorta, together with the aortic flow. The input impedance and derived characteristic impedance (0.056 mmHg/(ml/s)) are in agreement with in vivo measurements. Systolic pressure and pulse pressure are amplified over the aorta, as well as the first four pressure harmonics. The foot-to-foot wave velocity and the apparent phase velocity are derived between successive measuring locations. Aortic wave velocities range from 6 m/s (ascending aorta) to 15 m/s (abdominal aorta). The average of the high frequency components (> 5Hz) of apparent phase velocity corresponds well with the foot-to-foot velocity at the ascending aorta and lower part of the abdominal aorta. In between these locations, important reflections at the level of the renal arteries and splanchnic tree impede the determination of correct apparent phase velocity. This is in agreement with in vivo observations. Conclusions: The striking correspondence between in vivo observations and the model results shows that the physical model is an attractive tool for fundamental and applied haemodynamic research.

Keywords:
model, arterial tree, reflection, haemodynamic, aorta

Address for Correspondence:

Reference:
(CVE. 1998; 3 (1): 48-56)

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