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Qian, K X1; Wang, D F2; Topaz, S3; Yuan, H Y1; Ru, W M1; Zeng, P1; Kolff, W J2; Zwischenberger, J B2

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Purpose: To develop a prototype of axial flow, micro Aortic Valvo-Pump(AVP) in position of aortic valve in compliance with anatomy and physiology of native heart for long term LVAD. Description of Prototype: Current prototype of AVP is a bearing-less, nonpulsatile pump with dove egg size (24.7 mm in diameter and 12.4 mm in length at its largest point) and total weight of 40 g (rotor 11 g). The rotor has driven magnets and an impeller, and the stator consists of a motor coil and outflow guide vanes. Neither struts nor inflow and outflow tubes are necessary so that minimize the blood flow disturbance and blood resistance across the AVP. The attractive force between rotor magnet and stator coil iron core was minimized to enhance the durability without compromise of motor torque and efficiency. In vitro test: The prototype was tested in a close circuit with a pulsatile centrifugal pump to mimic native heart. Pulsatile pumping flow was generated by constantly rotating AVP, because of pulsatile inflow by mimic native heart. At 15,000 RPM, mean pulsatile pumping flow achieved more than 10 1/min and generate 100 mmHg systolic pressure. During diastole, 15,000 RPM prevents backward flow (zero blood flow cross AVP) from 80 mmHg diastolic pressure. The electricity consumption power is about 7 watts. The endurance test with saline has lasted 4 months (on going) and no mechanical wear can be detected.

Copyright © 2004 by the American Society for Artificial Internal Organs