Hello my name's scene in
faculty member in the school

by medical engineering at
Georgia Tech the laboratory that Iran

is called the cardiovascular
fluid mechanics laboratory and

the celebratory is celebrating its
thirtieth anniversary this summer.

We work in a multiple areas of research.

One from ten human dynamics
erotic Well McCann about Angie.

Mitral valve mechanics and
fluid mechanics of prosthetic heart.

All of these involve
the cardiovascular system and

namely in structural heart disease.

The first area that I want to talk to you
about relates to Funtown research that is

really complex anatomies that in
children with congenital heart defects.

As you can see in this picture the flows
that we see are extremely complicated.

Just to give you some background.

Single ventricle heart defects these

children born with a single
side of the heart.

OK Now proximately two
in one thousand birds.

This creates an abdominal
circulation as shown here

that needs to be corrected if
these children are to survive and

they need multiple cardiac surgery is to
correct this problem of their lifetime.

I work involves working with
pediatric cardiologist and

cardiac surgeons in providing
modeling test bed for

looking at work will surgeries
on in the bar in order for

the surgeon to plan out optimum
outcomes for these children.

In order to do this we
use an atomic information

obtained from Magnetic Resonance Imaging.

Images and these are reconstructed in
three dimensions as shown on the very

right hand side and an enemy that comes
about due to this surgical intervention.

M.R.I. also provides us
with velocity information

that we cannot obtain by any other
means in the human body this

detail information is useful in us
understanding how the surgical procedure.

Has been completed one of the tools
that we use in this is unique

to Georgia Tech is the works will surgery
environment that has been developed in

collaboration with the College of
computing that shows us being able to have

a virtual surgery done on these
congenital hearts in in this environment.

This allows us to try out different
types of an atomic configurations

then allows us to then use that to obtain

fluid dynamic information by computer
modeling what is shown here is for

its actual case in which we looked
at three different options for

a particular child in order to assess what
would be the optimum surgical procedure

based on this information that was then
given to a pediatric cardiac surgeon.

He decided that option three would be
the best to correct the congenital

defect in question and
this actually was done over a year and

a half ago and has resulted so
far in a very good outcome for the child.

Now changing gears and moving on to
the other another area that we were in is.

Looking at mitral valve mechanics and
that is looking at the valve shown here

that exists between the left and
the left ventricle and

here is a cut away from an actual human
heart as you can see this is an extremely

complex structure even from
an engineering point of view and

this valve has really been not studied to

the detail that it should in order for us
to provide information to the clinician.

What is shown here on this picture is a
two dimensional echocardiography came in.

Dynamic image of a patient
who has mitral valve.

Malfunction.

As you can see here.

All these colors going back and forth show
that this valve is not working properly.

And actually the valve
doesn't close off and

creates this big area back
flow which it should.

In order to study this here in
our laboratory at Georgia Tech.

We have created a unique flow simulator
where we can mount either human or

post scene mitral valve under various
conditions and here you're looking at

it from what we call an interview and
here you're looking at it for

a ventricle this is an actual vowed
functioning in a simulator and

it's similar to how it would
behave in the human heart.

This study here illustrates our
ability to alter the conditions

of the bow from a normal condition to
a path of physiologic condition and

then to understand more detail
what is going on when the valve is

functioning of Normally in order to get

some good information that could be
translated to the cardiac surgeon.

Here's another view of looking at a valve
that is not functioning properly on

the bench as you can see here this area
where the red light is showing that

means the valve is not quite up to you can
see daylight there and what this study

here on the left hand Carol shows
with the echocardiography is

that this is leaking so this is simulating
about that does not function probably.

Now one would ask the question how
accurate are the bench studies to

actual human studies and
here is an actual from a patient and

here's a simulation simulated
study on our bench and

if you will notice the flow patterns
especially about here in the left in

trim and here in the simulator left atrium
you will notice that those patterns

are very similar less training
that we can simulate on the bench.

Quite nicely.

It happens in pathophysiological
conditions in patients.

One area that we're getting into
now is against the surgical

environment where we're trying to
plan the surgery prior to going in.

This is a three dimensional
ultrasound measurement of about.

And this is the reconstruction
of looking at that annulus and

what we're trying to do here is provide
information once again to the surgeon to

show how his reconstruction or
his surgical techniques would influence

the function of this
well the thirty three.

I want to talk about is an area that
the lab is internationally known for

many years and it is in the fluid
mechanics of prosthetic heart valves

as the slide here from the American
Heart Association shows it's been

almost five decades since artificial heart
valves have been in the marketplace and

they have saved hundreds of thousands
if not millions of lives worldwide.

However these valves are not without
their problems as shown here.

Is a by leaflet mechanical valve
that is probably the most popular.

Well used today.

To replace our native valves and

you can see there are some
blood clots on that him pinned.

Impinging its function.

Studying this is quite challenging
because as you can see on this slide here

we have the flow that acts as downstream
of the valve which is quite complex but

it's at the microscopic level and here
when that hinge area where we found those

blood clots we see even more
complex low at a much smaller full

level this is on the order of two and
a half centimeters.

This is on the order of one hundred
microns so the scales at which we need

to understand what is going on to
blood cells goes from a two and

a half centimeters down to
one hundred micron level.

This shows again a variety of
tools we have an alibi artery for

looking at these flow fields.

This is using a visual technique
this is using a laser technique

for looking at the.

Lastly and also looking at what the city
that allows us to understand what could

potentially happen to blood cells that get
caught up in such disturbed flow areas.

This is another type of
out that is out there.

It's a parliamentary crowd that has
three leaflets that is similar in.

Overall design to the native
human he already crowd and

you can see from this set of.

From this video the floor that comes
through it is has a different pattern

to that of the by leaflet value so
earlier.

Some of our most recent work has been
really to investigate what goes inside

those hinge regions of these wells and

we have developed a very
powerful computational model.

Currently.

To look at this and
we are looking at how the flows

within the hinge these times when
the valve is closed and blood is leaking

through the hinge we can see that you
get very strong jets that come out and

this can be seen even more clearly
here in this visual illustration

this dynamic lustration where we have
ceded the floor with artificial particles

of different colors that allow us to see
how the flow Arkansas to the hinge but

want to point out here is
these extremely complex and.

Throughout the cardiac cycle as
the valve leaflet opens and closes.

In order to better understand this.

We also can from
the computational measurements.

Assess the shear stresses that are.

And these are the forces that would
on the blood cells as they go

through the hand and these give us
some idea as to what areas within

the hinge could be damaging
to the blood elements in

addition to these experiments that
are done computationally we do a set of.

Studies that involve actual blood
in a simulator where we can.

These valves in and measure parameters
of blood damage as shown here and

this shows a series of valves
that we have looked at and

each of them having different levels
of blood damage the final area

that I want to touch upon in
the last minute is about it.

This is far more biological
compared to the other studies we've

been doing up to now.

But clearly it is important
the native aortic valve undergoes

very large variations in
the forces that are clear on it.

This is during diastole.

And then during sisterly When flow goes
through the valve there is another set of

flow forces and we can occur in forces
that are one of our understandings of this

is to really to assess what happens to
the vow due to these mechanical forces.

The reason for this is to
understand valve calcification and

valve degeneration in people as they age.

The corn and played tissue culture system
is a system that we have developed

in our lab in order to program in
actual physiologic where forms and

suspend valve leaflet tissue
in the corn and plate system.

And these are some results that we have
obtained and this shows that under normal

conditions that the valve leaflets
behave biologically as expected.

And when there is.

Exposed to altered conditions of
sheer stress created by the corn and

plant system when you have it on
a path of physiologic condition.

We begin to see that the biology
begins to change and

begins to potentially lead to
Valve calcification another

type of force that the valve
leaflet sees is a stretch.

These are the lead as it opens and
closes it's stretched.

So this is a stretch by reactor that we
use that would allow us to look at the.

Fron conditions both normal and
abnormal and

one of the things we've see is when we
increase the stretch which can happen and

high blood pressure conditions for
example that most cells begin to die

on the valley fit then under
normal conditions of stretch.

Also the similar study
showed that the staining for

cows in the deposition are potential for
cancer in the position increased

when the stretch became
pathophysiological his bowels.

So what I've tried to show in these last
ten minutes is work that we're doing

in the area of cardiovascular research
going from what we call bench to

bassinet in the children and
from bench to bedside in adults

really to show the translational
nature of our research laboratory has

an international reputation and
a lot of the credit for this has to go to

the people who work in the lab this is a
photograph of the current research group.

Keeping in mind that this is well
spent over thirty years with.

Over forty to fifty Ph D.
students and thirty five to forty.

Masters students and over hundreds of
undergraduate students within the market.

Thank you.