New NC State computer models are contributing to more successful
vascular surgery, guiding the development of novel drug inhalation
therapies, and providing data for stricter federal air pollution standards.
Two such models have been created by interdisciplinary research teams
headed by Dr. Clement Kleinstreuer, a professor of mechanical and
aerospace engineering (MAE).
With funding from the National Institutes of Health through Duke
University, one team has developed and used a blood flow model
to create optimal
designs for synthetic blood vessels called grafts. Grafts are
used in femoral bypass surgeries as detours around a blockage
in the patients blood vessel, in kidney dialysis, and in
other peripheral vascular surgeries.
The newly designed, three-dimensional graft ends provide optimal
matching at the attachment to patients own blood vessels, smoothly directing
blood into the junction area. The results can be dramatic. With
the new graft end, the likelihood of a second surgery within two to
three years is significantly reduced from its current rate of 33 percent,
says Kleinstreuer. To go back on the operating table after two
to three years is not only traumatic but expensive. Team members
include Dr. P.W. Longest and doctoral student Zhonghua Li of NC States
MAE department, Dr. Joseph P. Archie of Wake Medical Center, Dr. George
A. Truskey of Duke Universitys Biomedical Engineering Department,
and Dr. Mark L. Farber of the UNC School of Medicine.
more elaborate blood flow model has provided specifications to
surgeons optimize placement of stents, grafts, and other
implants to avoid leaks and potential rupture of diseased arteries. With
optimal design, excessive blood vessel wall stresses are mitigated
or avoided, Kleinstreuer explained.
Yet another Kleinstreuer team, including Dr. Zhe Zhang, MAE
graduate students Huawei Shi and Burton Kennedy, and U.S. Environmental
Agency (EPA) collaborator Dr. C.S. Kim, has developed a computer
model of the upper respiratory system. The team has recently
model to track the way inhaled droplets and vapor of a highly
toxic military jet fuel are deposited in the lungs. That work,
the EPA, the U.S. Air Force, and the National Science Foundation,
has provided federal toxicologists with evidence of adverse
especially on children. It may also provide justification for
stringent air pollution standards proposed for 2005.
Perhaps even more dramatic, the lung aerosol transport model
and its controlled air particle stream methodology may
be applicable to development of inhaled medication, possibly
injections of drugs such as insulin for diabetics, or chemotherapy
for lung cancer patients.
With these technologies, we are not only helping to people live
longer lives, but also improving their quality of life, Kleinstreuer
said. And that translates into lower costs for society.