- Hi guys, I'm Olivia,
and I'm in the laser lab today with Wandi.
Wandi, do you wanna tell us about yourself
and your research?
- Yeah, Hi.
So I'm a final year student studying both
mechanical and bio-medical engineering.
My thesis topic is on CFD simulation
of patient-specific carotid artery stenosis.
And it's a very interesting topic because
the geometries that I use are real patient cases
and the results can provide meaningful information,
so it can help surgeons to determine
whether the patient requires surgical treatment.
- Yeah, so as you mentioned,
patient-specific geometry. - Yeah, yeah.
- Did you get that geometry from the surgeon?
- Yeah, so I got 15 patient geometries from the surgeon.
- So the geometry was from the surgeon.
- Yeah.
- And you mentioned you run CFD analysis?
- Yeah. - Do you wanna tell us
about what's your methodology and how do you do that?
- Yeah, so I use ANSYS Fluent for my simulation
and so, I have 15 patient geometries
and the boundary conditions I use
are also patient-specific velocity profile.
So I started from steady-state analysis
and moved to transient simulations.
- Yeah, so you ran transient simulation?
- Yeah. - So how'd you
get the velocity profile
and why is it so important to run a transient analysis?
- So for transient analysis,
I can get different hemodynamic factors,
including velocity profiles, time average wall shear stress,
and oscillator pressure index.
And because these parameters can protect
some issues within the carotid arteries,
so, for example, if the wall sheer stress is too high,
then it may damage the endothelial cells.
And if the wall shear stress is low
with high oscillator pressure index,
then it means that there could be possibilities
of plaque to build up.
- Yeah, so essentially the CFD analysis
helps you to see different factors,
different parameters that you can help
to understand what the vessel is trying to react on then.
- Yeah.
- So, were there any important parameters
that you look at besides the wall shear stress?
Do you look at velocity and?
- Yeah, velocity and oscillator pressure index.
- [Olivia] So, did you manage to see any correlation
- [Wandi] So, for the areas with low wall shear stress,
they usually have high oscillator pressure index.
And the velocity profiles are kind of
the low velocity recirculating turbulent flows.
- [Olivia] Yeah, so the velocity helps you to see
whether is turbulent
flow in recirculation? - Yeah.
- So, okay, that's really cool.
So I guess, as an undergraduate, were there any challenges?
Because it's such a big topic that you are looking at
geometry and real patient geometry and stuff like that,
were there any challenges along the way
when you do your analysis?
- Yeah so, some of the challenges include time limitation
because I ran all the cases under one cardiac cycle.
- Okay.
- But for more accurate results,
I should probably run them under three cardiac cycles.
And another limitation is mesh
because my license have a restriction
of I can't have over 500,000 mesh element,
so that was another limitation for me.
- Yeah, okay, so I guess, how did you overcome
the different challenges that you had?
- So I actually ran one case under three cardiac cycles.
- Okay.
- And I compared results of one cardiac cycle
and fortunately, there weren't too many
differences within the results.
- So you compared your different analysis
and then, run another? - Yeah.
- That's pretty cool.
- So, how do you think that your research
can further develop from here?
- So, for my thesis, I made a few assumptions.
I assumed the flow is Newtonian
and the vessel walls are rigid,
but in reality, they are not,
so blood isn't always Newtonian
and there is way less density.
So I would say these are the areas that should be
taken into account for further analysis.
- Okay, cool.
I hope that the results that you get
will be able to help surgeons
in the future. - Yeah.
- Thanks for chatting with me today.
- Thank you. - Thank you for your time.
- Yeah.