Pressurized Static Chamber to Determine Leaflet Strain

Transcription

1 Pressurized Static Chamber to Determine Leaflet Strain Team 10 Andrea Mandragouras, Michael Napolitano, and Victoria Fernandez Client: Dr. Wei Sun

2 Overview Introduction Types of valves being tested Purpose and Specifications Previous Design Optimal Design Important Subunits Budget Future Work Acknowledgements

3 Introduction: Heart Valves An estimated 95,000 valve surgery procedures are performed each year in the U.S. and aortic valve disease alone is responsible for more than 25,000 annual deaths. About 5 million Americans are diagnosed with heart valve disease each year. Valve problems can be present at birth, caused by heart disease, infections, or heart attacks. Some valve problems are minor and do not need treatment while others might require medicine, medical procedures, or surgery to replace or repair the valve. Heart Valve disease Valvular insufficiency this is considered a leaky valve because the heart valve does not close tight enough. Valvular stenosis - This occurs when a heart valve doesn't fully open due to stiff or fused leaflets.

4 Transcatheter Aortic Valves and Bioprosthetic Valves On left is the Edwards CEP Valve Bioprosthetic valve On the right is the Edwards Sapien XT Transcatheter valve The bottom picture shows how the aortic valve leaflets react with added pressure

5 Purpose A system to Test the leaflets strains under varied loading pressures. Determine amount of leakage of the leaflets at various pressures. Image the leaflets and create a 3-D view of the valve deformation.

6 Client Requirements The Device must accurately quantify the deformations in the three leaflets. be able to hold desired pressures without leakage of the system. simultaneously measure the transvalvular pressure. be able to measure leaflet strains in both surgical and transcatheter heart valves.

7 Previous Design High amount of leakage. Could not hold stable desired pressures. Calibration could only be done once. Time consuming: cleaning and set up of system. Not accurate pressure readings because of the use of a hand pump.

8 Optimal Design Holding Tank Mechanical Pump Divergent loop with 2 Valve controls Testing chamber Leakage container

9 Holding Tank Non-pressurized Water reservoir that will drain into the mechanical pump Hose attachment Water from divergence loop will flow back into the holding tank Limit air bubbles in the system

10 Divergence Loop Mechanical Pump Electric Centrifugal Water Pump ~ 36 liters/min Valves Y- Valves Control amount of water that flows through each part of the system (divergence loop/ testing chamber)

11 Testing Chamber Pressurized Water Range of 40 mmhg to 200 mmhg Pressure sensor at valve height Calibration Opening for easy calibration of system Valve Hold bioprosthetic /transcatheter aortic valve Use specific valve holder that is universal for all other machines in the lab

12 Leakage Container ~ Non-pressurized Pressure sensor at height of valve Completely filled with water Opening for water to spill over into a graduated cylinder to determine amount of leakage (liters/min)

13 Camera/Software High Speed Compact Digital Camera (CDC) to image the valve during testing Boroscopic lenses will be used to image the leaflets of the valve Images are collected via XCAP for Windows DataTrax will collect data from the pressure sensors

14 Budget

15 Future Work Anticipating to finish the machining of the individual parts of our design by winter break. Next semester will be dedicated to assembling and testing the system of heart valves. Also, we will need to re-design a Labview program that has the ability to analyze the three valve leaflets.

16 Acknowledgements Dr. Wei Sun Eric Sirios Peter Glaude