Completely pulsatile high flow circulatory support with a constant-speed centrifugal blood pump: mechanisms and early clinical observations

A hybrid passive/active magnetic bearing system was designed for a rotary centrifugal blood pump being developed for long-term circulatory support for heart failure patients. This system consists of two axially spaced bearing combinations for complete magnetic levitation of the rotor using only a single-axis active control. Each bearing combination comprises a pair of axially oppositely polarized permanent magnet rings on the rotor and a similar pair in the stator housing for both radial support and axial bias flux, and an electromagnetic coil to actively control the rotor axial position. The design permits a relatively large radial clearance between rotor and stator, and provides sufficient radial/axial stiffness, active controllability over the desired axial travel of the rotor. The bearing characteristics were evaluated by electromagnetic finite element analysis. The prototype pump was fabricated and levitated using a PID controller with zero-force balance algorithm to stabilize the rotor in the thrust direction and minimize the power draw. The experimental results confirmed the efficacy of the proposed magnetic bearing design and associated control algorithm.

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Hydrodynamic design and performance analysis of a centrifugal blood pump for cardiopulmonary circulation

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1243/095765005x31108 ◽

2005 ◽

Vol 219 (7) ◽

pp. 525-532 ◽

Cited By ~ 5

Author(s):

H W Oh ◽

E S Yoon ◽

M R Park ◽

K Sun ◽

C M Hwang

Keyword(s):

Performance Analysis ◽

Operating Conditions ◽

Blood Pump ◽

Circulatory Support ◽

Analysis Method ◽

Pump System ◽

Centrifugal Blood Pump ◽

Mock Circulatory System ◽

High Efficient ◽

And Performance

This paper presents the hydrodynamic design and performance analysis method for a miniaturized centrifugal blood pump using three-dimensional computational fluid dynamics (CFD) code. In order to obtain the hydraulically high efficient configuration of a miniaturized centrifugal blood pump for cardiopulmonary circulation, well-established commercial CFD codes were incorporated considering detailed flow dynamic phenomena in the blood pump system. A prototype of centrifugal blood pump developed by the present design and analysis method has been tested in the mock circulatory system. Predicted results by the CFD code agree very well with in vitro hydraulic performance data for a centrifugal blood pump over the entire operating conditions. Preliminary in vivo animal testing has also been conducted to demonstrate the haemodynamic feasibility for use of centrifugal blood pump as a mechanical circulatory support. A miniaturized centrifugal blood pump developed by the hydraulic design optimization and performance prediction method, presented herein, shows the possibility of a good candidate for intra and extracorporeal cardiopulmonary circulation pump in the near future.

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