CBET Award Achievements
Notable Accomplishments from CBET Awards
 

Fighting Cardiovascular Disease by Studying Arterial Flow Dynamics

Pavlos Vlachos  -  Virginia Polytechnic Institute and State University


Background:  Cardiovascular disease has been a leading cause of death in the US and accounts for approximately one third of all deaths worldwide.  Improving disease diagnostic tools and treatments requires understanding the physics of blood flow through the body.  As the heart pumps blood through the cardiovascular system it transfers nutrients and oxygen to all the tissues and organs via a very large arterial network consisting of numerous short curved flexible vessels with many branches that deform during each heartbeat.  The combination of these parameters, namely curvature, branching, flexibility and pressure pulsing, may result in flow disturbances that contribute to arterial disease.  The Vlachos Group at Virginia Tech studied via experimental methods the effect of these parameters and how flow disturbances correlate with various disease conditions.  Additionally, an educational component of this research is translating the fluids research work into engineering education.

Results:  The Vlachos Group used a holistic spatio-temporal analysis of arterial flows combining non-invasive velocity measurements and direct in-situ dynamic wall shear stress measurements.  The results demonstrate that, although arterial flows are primarily laminar, the combination of curvature, compliance and adverse pressure gradients triggers the development of random and intermittent flow structures that are inherently unstable.  Moreover, the research shows that though vascular stents open the vessel lumen, they also induce changes that promote flow structures similar to the ones observed downstream of stenosed arteries.

The educational effort to transform fluids research examples into the engineering classroom has reached over 450 students across all academic levels, from freshmen undergraduate to first-year graduate students.  Through the use of pre- and post-assessment tools, the Vlachos Group revealed that over 30% of these students do not previously appreciate the breadth of fluids applications or the educational value of research experiences until after completing the course.

The efforts so far have successfully laid the foundations for transformative research for both the technical and educational component of this project.

Pavlos Vlachos Image
 
This image depicts velocity and vorticity distributions along a curved stented artery.

Credit:  Pavlos Vlachos, Virginia Polytechnic Institute and State University


Scientific Uniqueness:  A unique combination of experimental tools will pioneer the development of a holistic framework for the approximation and analysis of flows in complex physiological systems and will deliver measurements not attainable with conventional methods.  Consequently, this effort provides new insight into the fundamental flow physics associated with cardiovascular flows and on the complex spatiotemporal dynamics of turbulence transition.

Impact on Industry and/or Society:  Understanding the fundamental complex physics of physiological flows will improve the understanding of the origin of cardiovascular disease processes and their relation to fluid flows, enabling the development of novel and improved diagnostics, treatments, and implantable devices.

Potential Economic Impact:  According to the American Heart Association cardiovascular disease direct and indirect annual costs in the US are in excess of $400 billion and are projected to exceed $1 trillion within the next decade.  Enhancing the understanding of the origin of arterial disease and improving diagnostic methods and disease treatments will have a direct impact on the cost of health care as well as on the quality of life.

This work is notable because the research will allow the development of metrics and indices that correlate fluid dynamics with the observed biological response of the cardiovascular system, providing an innovative model for interfacing between engineering and physiology.

This work is multidisciplinary.  This research involves fundamental fluid mechanics, experimental methods, optical flow diagnostics, MEMS sensors, cardiovascular physiology and pathology.

This project addresses the NSF Strategic Goals of:  (1) Discovery and (2) Learning.  The Vlachos Group has studied the physiological flows in an effort to stem cardiovascular disease.  The resulting work will lead to the development of metrics and indices relating fluid dynamics with the observed biological response of the cardiovascular system.  The results provide an innovative model for interfacing between engineering and physiology which will impact the fight against cardiovascular disease worldwide.  On an educational level, the Group exposed students to fluids research enhancing the engineering and science workforce of the future.

This Nugget represents transformative research.  This project represents high-risk research due to the high fidelity of experimental methodology adopted and due to the extremely complicated character of cardiovascular flows.



     
Program Officer:   William Schultz
     
NSF Award Numbers:   0547434
     
Award Title:   CAREER: Arterial Flow Dynamics-Effects of Pulsatility, Compliance and Curvature
     
PI Name:   Pavlos Vlachos
     
Institution Names:   Virginia Polytechnic Institute and State University
     
Program Element:   1443
     
CBET Nugget:   FY 2007
     

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This Nugget was Updated on 15 October 2008.