Fluid Dynamics Laboratory

Contact

Tina M. Morrison, Ph.D.
Matthew R. Myers, Ph.D.

FDA pump model evaluated (a) in a flow loop with blood, (b) using particle visualization, (c) using computational fluid dynamics.

Hydrodynamic performance of prosthetic heart valves evaluated using (a) in vitro simulators, and (b) computational fluid dynamics. Right - quantifying aerosol flow through electronic cigarettes.

Summary

The Fluid Dynamics Laboratory is interested in problems involving fluid flow, and the fluid interactions with medical devices and the human body. Our research primarily focuses on life-sustaining technologies and understanding the physical forces that act on different fluids. We aim to develop and validate assessment tools to assure the safety and effectiveness of medical devices in the following four areas:

1. Blood Damage Assessment in Medical Devices
   Blood-contacting medical devices such as catheters, ventricular assist devices, prosthetic heart valves, vena cava filters, oxygenators, and hemodialyzers have been widely used to treat patients suffering from cardiovascular diseases. Unfortunately, these types of devices can potentially damage blood elements (i.e., red blood cells and platelets) and may lead to life-threatening complications. Our work is intended to address how different blood properties and flow conditions within medical devices affect blood cell damage by developing different engineering models and flow systems to simulate physiologic blood flow, performing comparative testing of animal and human blood, and assessing red blood cell and platelet viability using various in vitro experimental techniques.

2. Computational Fluid Dynamics (CFD) Modeling of Medical Devices
   CFD is used as a tool for determining fundamental mechanisms of interaction between medical devices and the human physiology.  Various modeling techniques are applied to investigate emerging areas for computational modeling such as debris accumulation, platelet aggregation, aerosol transport, and imaging-phantom evaluation.

3. Experimental Quantification of Flow in Medical Devices
   Quantitative flow visualization measurements using particle image velocimetry techniques are conducted to evaluate the safety and performance of blood-contacting medical devices. In vitro flow field measurements are used to develop benchmark, inter-laboratory experimental datasets on simplified medical device models for validating CFD models. Hydrodynamic fluid performance of medical devices is quantified using in vitro physiologic models and mock circulatory loops representing both healthy and disease states. Other emergent health issues that are being investigated in our laboratory include miniaturized devices using microfluidic platforms, enteral feeding tubes, and morcellators.

4. Bio-Particulate Transport
   Bench-top experiments and mathematical models are used to study how personal protective equipment such as surgical respirators, surgical facemasks, and pediatric facemasks can reduce the risk of bio-aerosol related disease transmission to the general population. Our capabilities in this area allow for investigations of emerging regulatory issues across FDA such as e-cigarette aerosols and heater-cooler aerosolization of infectious agents.

Current funding sources

DARPA
FDA Critical Path Initiative
FDA Medical Countermeasures Initiative
FDA Center for Tobacco Products
FDA Office of Women’s Health
National Science Foundation
 

Personnel

FDA Staff:
Tina M. Morrison, Ph.D., Deputy Director
Matthew R. Myers, Ph.D., Laboratory Leader
Brent Craven, Ph.D.
Seyed Ahmad Reza Dibaji, Ph.D.
Suvajyoti Guha, Ph.D.
Prasanna Hariharan, Ph.D.
Luke Herbertson, Ph.D.
Qijin Lu, Ph.D.
Richard Malinauskas, Ph.D.
Stephen Retta, M.S., M.S.E.
Jean Rinaldi, M.S.BioE. 

Research Fellows:
Kenneth Aycock, Ph.D.
Alexander Herman, M.S.
Megan Jamiolkowski, Ph.D.
Alex Rygg, Ph.D.
Deepa Sritharan, M.S.
 

External collaborators

Ansys Inc.
GEDSA
George Washington University
Mayo Clinic
Mississippi State University
North Carolina A&T State University
Pennsylvania State University
Rochester Institute of Technology
Sandia National Laboratories
State University of New York, Binghamton
Thrombodyne Inc.
University of Cincinnati
University of Louisville
University of Maryland, Baltimore County
University of Maryland, College Park
University of Maryland School of Medicine
University of North Carolina
University of Pittsburgh
 

Resources

Blood Damage Area: microscopy, spectrophotometry, rheometry, centrifugation, flow cytometry, BSL-2 fume hood, blood gas analysis, thromboelastography, platelet activation/aggregometry, and immunological assays

Flow Visualization Area: particle image velocimetry (PIV), time-resolved PIV, high speed flow videography, pulsatile mock circulatory loops, steady flow systems, in vitro physiologic models, and pressure and flow instrumentation

Bio-Particulate Area: scanning mobility particle sizing, laser aerosol spectrometry, electrospray aerosol generation, ultrasonic aerosol generation, smoking simulator, and collision nebulizing

Public domain data & software

Experimental and CFD round-robin data from our benchmark models are available for download through Computational Fluid Dynamics at the National Cancer Institute (NCI), National Institutes of Health (NIH)

Software to calculate deposition of pathogenic bioaerosols in human lungs is available for download through MatLab Central

Relevant standards & guidance documents

Relevant Standards:

• ASME Verification & Validation 40 Standard for Assessing Credibility of Computational Models through Verification and Validation: Application to Medical Devices
• ASTM F1830-97 (2013) Standard Practice for Selection of Blood for in vitro Evaluation of Blood Pumps
• ASTM F1841-97 (2013) Standard Practice for Assessment of Hemolysis in Continuous Flow Blood Pumps
• ASTM F647-94 (2014) Standard Practice for Evaluating and Specifying Implantable Shunt Assemblies for Neurosurgical Application
• ASTM F756-13 Standard Practice for Assessment of Hemolytic Properties of Materials
• ISO 5840-1 (2015) Cardiovascular implants -- Cardiac valve prostheses -- Part 1: General requirements
• ISO 5840-2 (2015) Cardiovascular implants -- Cardiac valve prostheses -- Part 2: Surgically implanted heart valve substitutes
• ISO 5840-3 (2015) Cardiovascular implants -- Cardiac valve prostheses -- Part 3: Heart valve substitutes implanted by transcatheter techniques
• ISO 7197 (2016) Neurosurgical implants - Sterile, single-use hydrocephalus shunts and components
• ISO 10993-4 (2013) Biological evaluation of medical devices - Part 4: Selection of tests for interactions with blood
• ISO 14708-5 (2010) Implants for surgery — Active implantable medical devices Part 5: Circulatory Support Devices

Guidance

• U.S. Guidance for Industry and FDA Staff — Reporting of Computational Modeling Studies in Medical Device Submissions, September 21, 2016. 
• U.S. Guidance for Industry and FDA Staff – Use of International Standard ISO 10993-1, “Biological evaluation of medical devices - Part 1: Evaluation and testing within a risk management process”, June 16, 2016.

Selected peer-review publications

• Malinauskas et al, FDA benchmark medical device flow models for CFD validation, ASAIO Journal, 2017.
• Aycock et al, The importance of hemorheology and patient anatomy on the hemodynamics in the inferior vena cava, Annals of Biomedical Engineering, 2016.
• Morrison et al, The Role of Computational Modeling and Simulation in the Total Product Life Cycle of Peripheral Vascular Devices, Journal of Medical Devices, 2017.
• Hariharan et al, Verification benchmarks to assess the implementation of computational fluid dynamics based hemolysis prediction models, Journal of Biomechanical Engineering, 2015.
• Herbertson et al, Multilaboratory study of flow-induced hemolysis using the FDA benchmark nozzle model, Artificial Organs, 2015.
• Malinauskas et al, Working with the Food and Drug Administration’s Center for Devices to advance regulatory science and medical device innovation, Artificial Organs, 2015.
• Guha et al, Effectiveness of facemasks for pediatric populations against submicron-sized aerosols, American Journal of Infection Control, 2015.
• Lu et al, In vitro shear stress-induced platelet activation: sensitivity of human and bovine blood, Artificial Organs, 2013.