John Bluck

Feb. 24, 2000

NASA Ames Research Center, Moffett Field, CA

Phone: 650/604-5026 or 604-9000

E-mail: jbluck@mail.arc.nasa.gov

John Ira Petty

NASA Johnson Space Center, Houston, TX

Phone: 281/483-5111


NASA computer experts have been using a supercomputer to improve the
NASA/DeBakey miniature heart assist pump, leading to on-going human trials
with patients awaiting heart transplants. The experts suggested
improvements after simulating blood flow through the pump using a NASA
computer that normally models rocket fluid flow.

To date, physicians have implanted the heart assist pump in 25 patients
during European clinical trials. MicroMed Technology, Inc., Houston, TX,
manufactures the pump, now called the DeBakey VAD.

“Johnson Space Center, Houston, TX, and DeBakey Heart Center of Baylor
College of Medicine, Houston, asked us to help them because of our
experience with simulating fluid flow through rocket engines,” said Dochan
Kwak, a researcher at NASA’s Ames Research Center in California’s Silicon
Valley. He and colleague Cetin Kiris analyzed blood flow through the
battery-powered heart pump whose blade spins as fast as 12,500 rpm. “The
speed of fluid flow through a rocket engine is faster than blood flow, but
very similar in many ways,” Kwak noted.

During initial development of the one-inch by three-inch implantable rotary
heart pump, engineers noticed two major problems. Friction damaged blood
cells because the device created turbulent flows through many pump parts;
and there were stagnant regions in the pump that caused blood clotting, a
major problem with ventricle assist devices.

Following supercomputer simulations, the NASA researchers were able to
reduce red blood cell damage to an amount comfortably below acceptable
limits. The improved blood flow pattern also reduces the tendency for
blood clots to form.

“We worked with the team to make the blood flow more smoothly through the
pump; that also removed the stagnant regions,” Kwak said. NASA Ames
scientists first began assisting the NASA/Baylor team in 1993, and will
continue to help this year and possibly for a longer period.

“Without the support of the NASA supercomputer design experts, the pump
would not function as efficiently as it has,” said Dallas Anderson,
president and CEO of MicroMed, the company to which NASA granted exclusive
rights for the pump in 1996.

In the two years after receiving the license for the pump from NASA,
MicroMed gained international quality and electronic standards
certifications, got permission to begin clinical trials in Europe and
implanted the first device. The first patient, a 56-year-old man, received
the DeBakey VAD in November 1998, in Berlin. The pump functioned normally
and to its design specifications, Anderson said.

The device can pump more than 10 liters of blood per minute, about twice a
normal heart’s pumping needs. The pump has been in patients for as long as
four months thus far. Eight of the patients have already gone on to have
heart transplants.

“MicroMed will soon submit documentation to the Food and Drug
Administration (FDA) for permission to conduct human clinical trials of the
pump in the United States,” Anderson said.

The pump is based in part on technology used in Space Shuttle fuel pumps.
Developers predict that the heart pump will not only be a long term
“bridge” to transplant, but will serve as a more permanent device to help
recovering patients lead a more normal life. The concept for the pump began
years ago with talks between Baylor College of Medicine’s Dr. Michael
DeBakey and one of his heart transplant patients, the late David Saucier, a
NASA Johnson engineer who died in 1996.

Six months after his 1984 heart transplant, Saucier was back at
work. With fellow NASA employees, as well as Dr. DeBakey, Dr. George Noon
and other Baylor staff, Saucier worked evenings and weekends on the initial
pump design.

“Since my own transplant, I have spent a lot of time visiting
people who are waiting for a donor heart,” Saucier said at the time. NASA
began funding the project in 1992.


NOTE TO TV PRODUCERS: NASA video file satellite broadcasts about this
release including animation and interviews will be distributed today on
NASA TV. The video file airs weekdays at noon (EST), with replays at 3
p.m., 6 p.m., 9 p.m. and midnight. NASA TV is broadcast on GE-2,
transponder 9C, C-Band, located at 85 degrees West longitude. The frequency
is 3880.0 MHz. Polarization is vertical and audio is monaural at 6.8 MHz.
Producers can check the NASA TV website, http://www.nasa.gov/ntv/, for
updates to the broadcast schedule.