Upload
cardiacinfo
View
1.004
Download
2
Embed Size (px)
Citation preview
UCLA
Lenka Stepan1, Daniel Levi2, & Greg P. Carman3
1Biomedical Engineering IDP, UCLA2Mattel Children’s Hospital at UCLA
3Mechanical & Aerospace Engineering Department, UCLA
A Thin Film Nitinol Heart ValveA Thin Film Nitinol Heart Valve
UCLA
MotivationMotivation Replacement Heart Valves
Mechanical Valves Require medication Noisy
Bioprosthetic Valves Only Last 15 years
Open Heart Surgery
Thin Film NiTi Heart Valve Anti-thrombogenic
Doesn’t require medication Quiet Superior Durability
Doesn’t need replacement Percutaneously Placed
Goal: Test Durability of Thin Film NiTi Valve
UCLA
Valve DesignValve Design
Thin film NiTi leaflets anchored on NiTi wire using a C-tube
NiTi wire mesh embedding in inner Teflon scaffold
Outer Teflon tubing houses anchoring wire and inner teflon scaffold.
UCLA
Valve TestingValve Testing Pulsatile Flow Testing
Flow Rates Pressure Traces Durability Tests (10^6 cycles)
Biocompatibility Immersion Tests – Corrosion Animal Testing – Biological Response
Flow rate and Film Thickness
1.01
1.22 1.291.37
1.71
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
8 micron withSi
12 micron 16 micron 20 micron Edwards
Flow
rate
(L/m
in)
Durability: 10^6 cycles, Crystalline Thin Film NiTi leaflets with and without Silicone
0
0.4
0.8
1.2
1.6
2
1E+00 1E+01 1E+02 1E+03 1E+04 1E+05 1E+06 1E+07
Cycles
Flow
Rat
e (L
/min
)
NiTi with Silicone
NiTi
Intimal proliferation
Bare stentThin Film NiTi Covered stent
Strut damage
UCLA
Future WorkFuture Work
• Percutaneous Designs– Integrate Leaflets into a collapsible scaffold
• Biocompatibilty– Cytotoxicity– Electrochemical Corrosion Testing
• Accelerated Wear Testing– Fatigue