Biomedical Engineering Reference
In-Depth Information
Figure 18.11
The CorAide device for ventricular support. (With permission from Arrow International, Reading,
PA.)
et al., 1982); both had unfavorable outcome. It was in 1982 that the Jarvik-7 total artificial heart
(TAH) was implanted in Barney Clark by DeVries and colleagues (DeVries et al., 1984). This
operation attracted much public attention as a result of significant coverage in the lay media. The
New York Times went as far as calling this a ''Dracula'' of medical therapy. The following devices
are some of the clinically available TAH which have been used.
18.8.1
AbioCor Total Artificial Heart (ABIOMED, Inc, Denver, CO)
This device is composed of a high efficiency miniature centrifugal pump situated between the two
artificial ventricles; this system is implanted after removing the native heart. A two position
switching valve is used to alternate the direction of the hydraulic flow between the pumping
chambers resulting in alternate contraction of the chambers (Dowling et al., 2001, 2003). In
addition, there is a balance chamber which balances the volume between right and left sided
chambers. This device is in the initial clinical trial stage and at the time this publication went to
press, 15 patients have undergone device implantation.
18.8.2
CardioWest TAH (SynCardia Systems, Inc, Tucson, AZ)
This device is a precursor of the Jarvik-7. It is a pneumatically driven biventricular pulsatile
device (Figure 18.12) (Leprince et al., 2003). Blood collects in to a polyurethane blood sac and is
compressed by the air (Copeland, 2000; Copeland et al., 2001). There are two artificial
ventricles which are connected to the native atria. An external console delivers the compressed air.
18.8.3
Penn State TAH (ABIOMED, Inc, Denver, CO)
This device is an electromechanical TAH and consists of a titanium rigid case with blood sacs and
energy converters. The energy converter is a brushless DC electric motor. The actuation moves dual
pusher plates to both sides by a roller screw. It has low associated vibrations and minimal noise
(Weiss et al., 1999). It has a stroke volume of about 64 ml and can reach a maximum output of about
8 l/min. This device is in the preclinical testing stage.
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