1 / 14

Pulmonary Flow Resistive Device

Pulmonary Flow Resistive Device. Taya Furmanski Albert Attia Advisor: Thomas Doyle, M.D. March 17, 2003. Background. Hypoplastic Left Heart Syndrome (HLHS) is a condition in which the patient is missing his/her left ventricle 1440 babies are born each year with HLHS

tessa
Télécharger la présentation

Pulmonary Flow Resistive Device

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Pulmonary Flow Resistive Device Taya Furmanski Albert Attia Advisor: Thomas Doyle, M.D. March 17, 2003

  2. Background • Hypoplastic Left Heart Syndrome (HLHS) is a condition in which the patient is missing his/her left ventricle • 1440 babies are born each year with HLHS • Approximately 75% 3-year survival rate • No medical treatment for HLHS • Only options are operation (reconstruction) or transplantation • 300 patients with HLHS are seen at VUMC per year

  3. The Problem • Inadequate systemic blood flow • Amount of O2 delivered to the organs decreases significantly • “Blue Baby” • Flow schematic

  4. How to Solve the Problem • Place nozzle in pulmonary arteries (see figure for location) • Device will act as resistor • Decrease in pulmonary blood flow will cause increase in systemic blood flow • Eliminates first two steps of reconstructive surgery • Length of duration in heart = 6-8 months

  5. 1-3 L/min Systemic Artery <1 L/min Systemic Artery 1 L/min Pulmonary Artery 2-3 L/min Pulmonary Artery 1 L/min Pulmonary Artery 2-3 L/min Pulmonary Artery 3-5 L/min Right Ventricle 3-5 L/min Right Ventricle Schematic of Flow with and without Device Implanted WITHOUT DEVICE WITH DEVICE

  6. Dimensions of the Nozzle • Calculations by Craig Russell (ME student) • Theories required to solve problem • Conservation of mass • Conservation of momentum • Dimension of end of nozzle still to be determined • Pulmonary artery pressure ~20 mmHg 6-10 mm

  7. Alternate Solutions • Place nozzle inside stent • Use bow-tie shaped stent (see figure) • Placing a mesh-like device in the pulmonary arteries

  8. Problems With Alternate Solutions • Extremely difficult to place in the artery • Placement also a problem • Would cause hemolysis (tiny holes would damage red blood cells)

  9. What We Need- Modeling - • In vitro model to simulate the blood vessels • Prototype can be tested through model to determine effectiveness • Computer model would allow variables to be altered easily to determine the optimal dimensions of the device

  10. What We Need- Materials & Assistance - • Use Vanderbilt shop to mold conical device • Use materials to create physical model that accurately portrays operation of device • Assistance of mechanical engineering students (Craig Russell and Chris Owen) and professor (Dr. Mark Stremler) for fluid dynamics • Find experienced programmer to develop computer modeling system or use one currently in existence

  11. Why Nitinol? • Biocompatible • Memory wire—can be molded to desirable shape • Can be elongated to fit into catheter, enabling insertion

  12. What We Have Accomplished Thus Far… • In-depth research of HLHS • Several meetings with Dr. Doyle to discuss the problem and possible solutions • Finalizing a design plan • Create a plan of attack: start simple and increase complexity • Ordered and received nitinol wire • Calculations of fluid dynamics • Finalized method of implantation

  13. What We Have Yet to Do… • Produce prototype of device • Test prototype • Use Mechanical Engineering lab to test pressure drop across device • Pressure drop calculations will allow proper calculation of dimension of the nozzle • Create or find computer model simulation of cardiovascular system

  14. References • Barber, Gerald. Hypoplastic Left Heart Syndrome. Structural Congenital Defects, section 3. • www.ucch.org/sections/cardio/new/hlhs.html; date accessed: January 30, 2003. • web1.tch.harvard.edu/chnews/03-15-02/fetalcath.html; date accessed: February 10, 2003. • Dr. Thomas Doyle; Vanderbilt University Medical Center. • http://www.nemours.org/no/ncc/cardiac/crd1524.html

More Related