ELEMENTARY THEORY OF SYNCHRONOUS ARTERIO-ARTERIAL BLOOD PUMPS.
AVCO EVERETT RESEARCH LAB EVERETT MASS
Pagination or Media Count:
In the technique of arterio-arterial pumping, a volume of fluid is withdrawn from the aorta during systole and reinjected during diastole, thereby reducing the systolic pressure of the heart and adding energy to the systemic circulation. It is found that an upper bound for the effectiveness of such devices is given by the formula delta Q sub hQ sub hu - delta P sub 1P sub 1u Q sub bQ sub hu P sub 1u - P sub 2uP sub 1u where Q sub hu is the stroke output of the unaided heart and delta Q sub h is the increment caused by the pump with a stroke Q sub b. P sub 1u and P sub 2u are the systolic and diastolic pressures unaided. Delta P sub 1 is normally negative and represents the reduction in ventricular pressure. The division of effort of the pump between the reduction of pressure and the increase of flow depends on the physiological-mechanical impedance of the heart. The total effect is, however, independent of the impedance. Author
- Anatomy and Physiology