Social, Cultural and Educational Legacies - ER - NASA

The DeBakey VAD ® functions as a “bridge toheart transplant” by pumping blood throughoutthe body to keep critically ill patients alive until adonor heart is available.These illustrations show a visual comparison ofthe original ventricular assist device (top) and theunit after modifications by NASA researchers(center and bottom). Adding the NASAimprovements to the MicroMed DeBakey VAD ®eliminated the dangerous backflow of blood byincreasing pressure and making flow morecontinuous. The highest pressure around theblade tips are shown in magenta. The blue/greencolors illustrate lower pressures.So, what was it that Dave Saucier andthe other engineers at JSC thought theyknew that could help make a VAD workbetter, be smaller, and help thousandsof people seriously ill with heart failureand waiting for a transplant? Well,these folks had worked on andoptimized the turbopumps for theshuttle main engines that happen tohave requirements in common withVAD. The turbopumps needed tomanage high flow rates, minimizeturbulence, and eliminate air bubbles.These are also requirements demandedof a VAD by the blood and body.In the beginning, VADs had problemssuch as damaging red blood cells andhaving stagnant areas leading to theincreased likelihood of blood clotdevelopment. Red blood cells areessential for carrying oxygen to thetissues of the body. Clots can preventblood from getting to a tissue, resultingin lack of oxygenation and buildup oftoxic waste products that lead to tissuedeath. Once engineers resolved theVAD-induced damage to red blood cellsand clot formation, the device couldenter a new realm of clinical application.In 1996 and 1999, engineers from JSCand NASA Ames Research Center andmedical colleagues from the BaylorCollege of Medicine were awarded USpatents for a method to reduce pumpingdamage to red blood cells and for thedesign of a continuous flow heart pump,respectively. Both of these wereexclusively licensed to MicroMedCardiovascular, Inc. (Houston, Texas)for the further development of the small,implantable DeBakey VAD ® .MicroMed successfully implanted thefirst DeBakey VAD ® in 1998 in Europeand, to date, has implanted 440 VADs.MicroMed’s HeartAssist5 ® (the 2009version of the DeBakey VAD ® )weighs less than 100 grams (3.5 oz),is implanted in the chest cavity inthe pericardial space, which reducessurgical complications such asinfections, and can operate for as manyas 9 hours on battery power, therebyresulting in greater patient freedom.This device not only acts as a bridgeto transplant, allowing patients to livelonger and better lives while waitingfor a donor heart, it is now a destinationtherapy. People are living out theirlives with the implanted device andsome are even experiencing recovery,which means they can have the deviceexplanted and not require a transplant.Making Oxygen Systems SafeHospitals, ambulances, industrialcomplexes, and NASA all use 100%oxygen and all have experienced tragicfires in oxygen-enriched atmospheres.Such fires demonstrated the needfor knowledge related to the use ofmaterials in oxygen-enrichedatmospheres. In fact, on April 18, 1980,an extravehicular mobility unit plannedfor use in the Space Shuttle Programwas destroyed in a dramatic fireduring acceptance testing. In responseto these fire events, NASA developeda test method and procedures thatsignificantly reduced the danger.The method and procedures are nownational and international industrialstandards. NASA White Sands TestFacility (WSTF) also offered courseson oxygen safety to industry andgovernment agencies.During the shuttle era, NASA madesignificant advances in testing andselecting materials for use inhigh-pressure, oxygen-enrichedatmospheres. Early in the shuttle era,engineers became concerned that smallmetal particles could lead to ignitionif the particles were entrained in the277°C (530°F) oxygen that flowedthrough the shuttle’s Main PropulsionSystem gaseous oxygen flow controlvalve. After developing a particleimpact test, NASA determined that thestainless-steel valve was vulnerable toparticle impact ignition. Later testingrevealed that a second gaseous oxygenflow control valve, fabricated from analloy with nickel chromium, Inconel ®718, was also vulnerable to particleimpact ignition. Finally, engineersshowed that an alloy with nickel-copper,Monel ® , was invulnerable to ignition byparticle impact and consequently wasflown in the Main Propulsion Systemfrom the mid 1980s onward.490Industries and Spin-offs