Dr. Arash Kheradvar

Dr. Arash Kheradvar speaks about KLAB and cardiovascular engineering

Dr. Arash Kheradvar established KLAB in 2007 to devise solutions in cardiovascular fundamental and translational research areas. KLAB is currently part of the Edwards Lifesciences Center for Advanced Cardiovascular Technology at UC Irvine.  Dr. Kheradvar has written extensively about flow visualization in cardiovascular systems, including Vortex Formation in the Cardiovascular System.

ViVitro Labs Senior Research Biomedical Engineer, Dev Amatya PhD, had the pleasure of attending a lecture by Dr. Kheradvar as a student in 2007 and recently spoke with him about KLAB, the transcatheter mitral valves race, ViVitro Products meeting FDA testing requirements, the importance of high speed flow visualization, and advice to medical device start-up companies.

VL:  Please tell us about your current projects.

AK: My research is focused on three different branches of cardiovascular engineering: Heart valves engineering, development of cardiovascular imaging technologies, and cardiac biomechanics mainly on congenital heart diseases.

  • In Heart Valve Engineering, we’re developing four heart valves in our pipeline and one has graduated to a start-up company.
  • For imaging, we’re working on ultrasound and MRI.  With ultrasound we have developed a technology called volumetric echo particle image velocimetry (V-Echo PIV) which looks into the flow field in 3D and trying to get the flow visualized in 3D via ultrasound.  It’s an exciting new field in PIV. We’ve already developed a 2D system   and are now working on a 3D system.
  • Our third project is mainly focused on congenital heart and our disease of interest is Tetralogy of Fallot.

VL:  V-Echo PIV is an exciting development.  Are you satisfied with 2D accuracy of V-Echo PIV? 

AK: Comparing 2D and 3D is similar to when all the phones were wired.  When wireless came in, you cannot go back to wired.  In early 90s everyone was happy with a dot matrix printer.  When laser and color printers arrived one can’t go back to dot matrix.  3D technology and imaging will be the same thing. Currently everyone is happy with 2D, but when 3D advances, no one will go back to 2D.   When you look at a 2D flow, you’re basically looking at the mirror object of a 3D structure on a 2D plane.  So many phenomena can be missed by just looking at 2D image of 3D object.  I think that will have a lot of impact in the cardiovascular field.  It will have a lot of impact in respect to better diagnosis of diseases like diastolic dysfunction, a congenital heart disease with that typical has very complicated flow structures.

VL: Does your work on V-Echo PIV indicate a move away from traditional PIV modality? 

AK:  No, traditional PIV modality are not the focus of our scientific research work, but they are critical every day tools we use for so many things.  For example, high speed PIV operating at 1000 frame per second is very important for flow visualization in our mock up heart chambers.  A heart beat of 65-80 beats per minute requires time resolution of 1 millisecond to get the proper flow features.  Anything less could result in a lot of inaccuracies and you miss out on a lot of the flow features required in understanding the time development of the cardiovascular flow.

VL:  Do you use high-speed flow visualization assessment when you are designing the heart valves in your current pipeline? 

AK: Since 2007 I’ve been using just high speed PIV.  Every development in the lab is based on high speed PIV.

VL:  Do you use any ViVitro Labs equipment in your work?

AK:  We use your SuperPump pulsatile pump with the ViVigen waveform generator and pressure transducer system.

The SuperPump pulsatile pump is pretty reliable, I really like it.  We attach it to our own system and use the pumping mode.  The pressure transducer system was accurate when it was new but now we have had it for a while and still is functional.  The overall equipment is adequate for start-up companies to do a lot of their required FDA testing.

VL: Some of our customers are interested in the programmed waveforms that come with the ViVigen waveform generator.  Could you please speak about your experience with the programmed wavforms?

I’m using the waveforms in ViViGen for most of the studies.  For Aortic flows these are fine.  It is pretty accurate for a lot of studies and for FDA testing requirements the ViVitro system is pretty good.  For mitral valves, we program in our custom waveform    [Editor`s note: ViVigen offers the user the flexibility to program in custom waveforms.]

VL:   What do you think about the race to produce the first transcatheter mitral valve from a cardiovascular flow perspective?

AK: I have a different stand point with many people in the field.  Valve companies are treating the mitral valve as the aortic valve.  The mitral valve itself can be considered an ‘organ’ in the heart.  The mitral valve is a  bi-leaflet valve with a saddle-shaped dynamic annulus, , which is deflecting back and forth during the heart cycle.  There is a reason that nature designed the mitral valve in this way.  This dynamic motion is crucial in the design of a replacement valve regardless if it is transcatheter or surgical modality.  If you rigidify the annulus you are kind of killing the help provided by the motion of the annulus during pumping mode of the left ventricle.

VL: Who has influenced you in cardiovascular?

AK:  Professor Gharib has been advisor and mentor.  I have a lot of respect for him and a  genius and a fantastic person to work with.  He is an early pioneer of field of PIV.  He developed the technique in parallel with Ronald Adrian around 1993-94 which started the whole field in cardiovascular flow visualization.    I’ve always been influenced by the work of cardiovascular people.  Professor David Sahn at Oregon Health and Science  University has been a mentor to me.  He is a master of pediatric cardiology.  I’ve worked with Dr. Philip Kilner of Imperial College. I’ve learned a lot from him as well.

VL:  Any advice to start-up companies? 

AK:  The start-up field is an interesting arena.  Access to funds is important.  The field is evolving especially in transcatheters space. People come in every day with new ideas.  Overall the most important thing is to keep costs low and work with experts.  You don’t need to develop all the expertise in house.  It’s much easier and cheaper to develop relationships and subcontracts with experts in my experience.

Read more interviews with Cardiovascular Pioneers.

Research by Dr. Arash Kheradvar using ViVitro equipment or services:

Three-dimensional reconstruction of cardiac flows based on multi-planar velocity fields

A Tri-Leaflet Nitinol Mesh Scaffold for Engineering Heart Valves

An In Vitro Study of Changing Profile Heights in Mitral Bioprostheses and Their Influence on Flow

Correlation Between Vortex Ring Formation and Mitral Annulus Dynamics During Ventricular Rapid Filling

The Effects of Positioning of Transcatheter Aortic Valve on Fluid Dynamics of the Aortic Root


High-speed particle image velocimetry to assess cardiac fluid dynamics in vitro: From performance to validation

On Mitral Valve Dynamics and its Connection to Early Diastolic Flow

Influence of Ventricular Pressure Drop on Mitral Annulus Dynamics Through the Process of Vortex Ring Formation:

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