RESEARCHERS DEVELOP NEXT GENERATION OF ARTIFICIAL HEARTS 

	CHARLOTTESVILLE, Va., Feb. 25 -- In the coming months,
researchers at the University of Utah and the University of Virginia
will begin testing a new generation of smaller, more sophisticated,
and longer lasting artificial hearts.
	The two teams of biomedical researchers -- including cardiac
surgeons in Utah and engineers in Virginia -- just learned they will
share a $3 million, three year, research grant from InterMountain
Health Care. InterMountain Health Care is a not-for-profit corporation
that runs a hospital system in Utah.
	Three-quarters of the grant will go to medical researchers at
the University of Utah who will begin testing a new, continuous-flow
prototype pump on animals this summer. Utah's researchers are
internationally known for their work in artificial heart development
and cardiac surgery. It was at Utah in 1982 that the Jarvik-7
artificial heart was implanted in Barney Clark, the world's first
recipient of a "permanent" artificial heart. 
	The U.Va. team will devote its share of the grant to covering
the costs of testing the model now under development and building new,
smaller, and more sophisticated prototypes of the heart assist
devices. 
	About 300,000 Americans die each year from degenerative heart
disease, but for a number of reasons -- medical, financial, logistical
-- only about 3,000 heart transplants are performed each year.
Researchers believe the unmet market demand for heart transplants is
at least 100,000 people each year -- people who could live long,
productive lives if reliable artificial hearts were available. 
	The current solution is to provide some patients -- fewer than
3,000 each year -- with artificial, bridge-to-transplant hearts. These
cumbersome, grapefruit-sized devices enable people to survive, in bed,
for six months to a year, waiting for a compatible human heart to be
found. But these artificial hearts are only a temporary solution. No
"permanent" (that is, offering a life of 10 to 20 years) artificial
hearts have been approved for routine medical use by the U.S. Food and
Drug Administration, which regulates medical devices.
	In 1989, a group of professors at U.Va.'s School of
Engineering and Applied Science founded the Center for Magnetic
Bearings, a technology development center, in connection with
Virginia's Center for Innovative Technology. Then in 1991, the Utah
artificial heart researchers sought out the U.Va. engineers because of
this expertise. 
	In a previous heart pump prototype, Utah researchers had used
ball bearings to operate the propeller-like "impeller," or rotating
blade, but the ball bearings "sheared" the blood, grinding up red
blood cells within two hours. So, the Utah team sought to create a new
prototype that used magnetic bearings. These would allow the impeller
to be suspended in the blood flow, greatly reducing friction and
eliminating damage to the blood cells as the pump operated.
	In addition, researchers wanted to reduce the number of moving
parts and chances for mechanical failure. Current pulsating heart
pumps have more than 100 moving parts and associated reliability
problems. They typically last only a year or two, according to Paul
Allaire, a professor of mechanical engineering at U.Va. In contrast,
the U.Va.-Utah prototype has only one moving part -- the pump impeller
-- which boosts the device's expected lifetime to more than 10 years,
he said. 
	The circular design of the inside of the pump and a single
moving part, the impeller, also minimize the chances of thrombosis, or
potentially fatal blood clotting.
	The U.Va.-Utah team's current prototype, the CFVAD3, is
essentially the shape and size of a hockey puck, made of
rust-resistant titanium and weighing about three pounds. A hollowed
out interior holds the impeller, a lightly fluted, concave disk that
spins on a center pin at about 2,000 rpm. The pump is operated by
eight electro-magnets that need 25 watts of power. A heart patient
with the device would supply the power through external batteries worn
in a vest.
	Engineers later this year will build four more models of
CFVAD3 (Continuous Flow Ventricular Assist Device), which is about
half the size and half the weight of its predecessor. The previous
model, the CFVAD2, was the first ever built with full magnetic bearing
suspension. It weighed about 15 pounds and was about 4 inches by 7
inches.
	The U.Va. engineers have two more experimental versions of the
heart pump on the drawing board: one that is expected to be half the
size and half the weight of CFVAD3, with an impeller that spins twice
as fast at about 4,000 rpm; and another that will use permanent
magnets instead of electro-magnets, thereby eliminating the need for
electricity, coils, wires and external batteries.
	With the number of people needing artificial hearts holding
steady, and about 10 teams around the world conducting related
research, the race to design and manufacture the next generation of
artificial hearts is on. 
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February 24, 1997
	For more information call Paul Allaire at (804) 924-6209.
Television reporters should call our TV News Office at (804) 924-7550.