Associate Professor, Department of Mechanical Engineering
Research areas: unsteady fluid flows, flow-acoustic coupling, and fluid-structure interactions
Dr. Peter Oshkai brings his expertise in fluid mechanics to the biomedical field, conducting experimental research into the hydrodynamic characteristics of blood flow through replacement heart valves and cardiovascular stents.
For Oshkai, whose educational background includes both applied mathematics and mechanical engineering, transitioning into the biomedical field was simply a natural progression.
“Valves in pipeline systems and heart valves in cardiovascular systems are fundamentally similar, from the fluid mechanics perspective,” says Oshkai, “so it’s natural to extend the expertise that we develop in one area to the other.”
Quantitative flow imaging. Oshkai approaches his research from two distinct but complementary angles: experimental and theoretical. His experimental work relies heavily on quantitative imaging techniques, such as particle image velocimetry (PIV), which allow him to observe and study fluid flow patterns.
“We build scaled models of biomedical devices, such as heart valves and stents, and study them under laboratory conditions that have repeatable flow patterns,” says Oshkai.
PIV is a technique that allows researchers to capture photographs and videos of fluid as it flows through a given structure. By tracking the movement patterns of tracer particles within the fluid at distinct time points, scientists are able to calculate and map fluid velocity. These maps provide valuable information about flow dynamics, patterns and forces within the model being tested. This data can then be used to make inferences about the device ‘in vivo’, for instance, the characteristics of blood flow through an artificial cardiac valve.
Mathematical modeling. Oshkai also develops mathematical models that allow for cardiac flow simulations that generate equally valuable theoretical or predictive data. Modeling techniques allow researchers to study the effects of modifications to the system without having to make time-consuming and cumbersome adjustments to the actual experimental setup.
While Oshkai conducts research into a host of biological flow systems, two of his main projects revolve around cardiac replacement valves and cardiovascular stents. Working in collaboration with both industry and academia, Oshkai uses his expertise to help physicians make better decisions about cardiac surgeries and improve outcomes for cardiac patients.
Valves. One of Oshkai’s research projects focuses on determining which type of replacement heart valve (there are numerous different designs on the market) is optimal for different categories of cardiac disease. Oshkai is currently focusing on 2 medical conditions: stenosis, which is the unwanted narrowing of blood vessels; and insufficiency, or incomplete valve closure.
By studying the fluid dynamics associated with different valve designs, Oshkai can detect unnatural flow patterns. Unnatural flow patterns can damage blood platelets and lead to the development of dangerous blood clots. They can also result in areas of increased stress on vessels walls and cause potentially fatal aneurisms.
Currently, Oshkai is working in collaboration with ViVitro, a division of StarFish Medical, assisting with experiment design and test systems aimed at assessing the efficiency of new valve designs. He is also studying valve calcification — an accumulation of calcium deposits that can decrease valve functioning over time.
Stents. Oshkai also studies cardiac stents, little tubes that are surgically implanted within vessels to increase their strength. He’s particularly interested in changes to flow patterns that result from stent implants, as well as how stents are affected by the distinct flow patterns associated with different diseases.
He works collaboratively with research teams from both the University of British Columbia and the Polytecnico di Milano, whose goal is to develop software that will assist surgeons with effective stent placements.
“For any given stent design and location within a vessel, the software can help predict the mechanical forces on the stent, on the vessel walls, as well as the blood flow patterns,” says Oshkai. This is important because a stent that is placed in a less than ideal location could be subjected to abnormally high flow forces that might dislodge and dislocate it.
This type of interdisciplinary collaboration is exactly what draws Oshkai to biomedical engineering. Oshkai is also attracted to the “noble” nature of biomedical research; new discoveries frequently translate into tangible tools and techniques that benefit society as a whole.
“I think the potential for real advancement often lies at the interface of fields that were previously separate,” says Oshkai. “I think, fundamentally, all scientists and engineers are trying to find the answers to questions that have not yet been answered.”