Jarvik Heart, Inc.

The Best Way Usually Isn’t the Easiest
For some manufacturing sectors, pursuing the easiest means
of production is an acceptable goal. For manufacturers of
sensitive medical devices, such an approach is rarely possible,
let alone preferable. Jarvik Heart, Inc. of New York defines its
goal as pursuing the best solution and then working to make
it possible. A recent installation of a GF AgieCharmilles wire
EDM machine demonstrates the company’s constant commitment
to excellence, even when it is far from easy to accomplish.
Dr. Robert Jarvik possesses over thirty years of experience
in the field of medical device design and production. Working
with a team of researchers at the University of Utah in the
1970’s, he developed the Jarvik-7, the world’s first total artificial
heart designed to provide lifelong support. Since 1987,
he has continued his efforts to develop devices for people
with severe heart failure at a facility occupying four floors of
a building in Manhattan. Recently, this unique location presented
a significant hurdle in implementing the best available
production solution.
In April 2004, Jarvik Heart was awarded a $5 million contract
from the National Institutes of Health (NIH). The goal was to
develop a miniaturized version of the highly successful Jarvik
2000 VAD (Ventricular Assist Device) for use in children and
infants with congenital heart defects. At present, children with
such conditions face extremely dire odds.
There is a cumulative 50% mortality rate for the multiple
operations necessary in the first two years of life for children
with some of the more serious heart defects. After that, only
one in ten children receive a donor heart. Additionally, those
lucky few may spend years waiting, with a reduced quality of
life due to liver damage, fluid build-up in the abdomen and
other associated complications. The development of a permanent
VAD will have tremendously positive effects on these
children born with the cards stacked against them.
For nearly four years, Dr. Jarvik and his team worked tirelessly
to reduce the size of the Jarvik 2000 to the point where
it would be suitable for pediatric use. Unfortunately, smaller
designs created a host of problems.
“We found that we could not just shrink the existing design,”
says Dr. Jarvik. “With a smaller pump, we continually had
problems with thrombus formation within the device. This was
a severe problem, as it would eventually lead to premature
pump failure. A small thrombus would form around the bearings
and cause enough friction to stop the rotor from spinning.
The tiny motors don’t have enough torque to overcome this
binding force.”
Late in 2007, Dr. Jarvik made a breakthrough in the concept of
a pediatric VAD. While the exact details are confidential, it can
be said that the turning point involved a redesign of the bearings
used in the pump. Extensive calculations and initial prototype
testing suggested that the solution had been found and
the question became how best to machine the component.
It would require several sharp angles and levels of accuracy
and surface finish exceeding the capabilities of Jarvik Heart’s
existing equipment, so the team began examining its options.
“We found ourselves in a very tight spot,” says Dr. Jarvik. “Our
annual review with NIH was just over two months away and we
felt it was imperative that we be able to prove the benefits of
the new design in that time. Because of its size and requirements,
we knew the part would need to be machined on a wire
EDM. It was a matter of finding the right machine and proceeding
with its installation as quickly as possible.”
After some initial investigation into the capabilities of various
makes and models of machines, Jarvik Heart requested test
cuts from several EDM manufacturers. Based on the results,
the company chose the AC Classic V2 from GF AgieCharmilles.