The Artificial Heart: Not Just a Pump By Wray Herbert

The need/want for artificial hearts dates back to about the 1940s. It became more and more publicized in the hit 1970s television show "Six Million Dollar Man". Also the success of the space program of the 1960s gave much hope for other inventions such as the heart. Then in 1988 New York Times' editor said, "the Federal project to create an implantable artificial heart is dead", thus hope for the heart simple "died" off... but not for long.



Barney Clark was the first person to receive a permanent medical heart, called the Jarvik-7--inventor Robert Jarvik; however, he passed on 112 days later. He was hooked up to a very large and loud machine to power his heart. He went through many problems such as convulsions, cognitive problems, and kidney failure, where he eventually died of "massive organ failure". Even though this first trial was a failure, four more patients received the Jarvik-7 heart, one of whom was William Schroeder who survived 620 days!



Many thought that the heart was merely a simple four pump machine..they were mistaken. Alfred Bove said: "the God-given heart is dynamically balanced, finely-tuned organ, with the capacity to generate force, raise and lower pulse. It's impossible to get that in an artificial heart". But. Alfred, we can get mighty close, now. According to Robert Kung, chief scientific officer at Aboimed, a Danvers, Mass., we may have been too eager to implant the Jarvik-7 into patients. In this case building a rocket would be easier because the trajectory and velocities can be figured with math and science, building a heart is more like a feel, its more complex. Kung now is working on an improved Jarvik-7 called AbioCor.



Problems with the artificial heart was the inventors/medical scientists may no to have fully understood how the blood flows and circulates. Blood wants and needs to flow smoothly if it moves lazily it will clot, and yet can damage the cells and cause blockages. The AbioCor is made of special titanium and polyurethane blend that makes it easier for the blood to flow through the slick surface. The Jarvik-7's terrible pump caused jolting of the whole body, it was painful and uncomfortable. AbioCor had some clinical trials, only with the extremely ill though, and they were unable to save them, mainly because of stokes. Something needs to be done about clotting! The answer is cuffs that connect to the artificial heart and help regulate the circulation. Another big problem with any transplant surgery is infection.

AbioCor didn't use a large and painful pump but electricity--from an outlet or battery of some sort. It sends energy across the skin in waves so no tubes needed to be inserted. This also helped decrease infection. Thus far AbioCor is more convenient and efficient. However it is the size of a grapefruit, too large for anyone that's not a full grown man. AbioCor II is in the process of being drafted, this will be 30% smaller. The time of survival increased to 17 months. So it seems as if we are on the way to becoming successful in creating an artificial heart that can keep one alive longer.

My thoughts:
I find it intriguing that many scientists under estimated the complexity of the heart. It seems simple enough to have a four chambered pumping organism. But we cannot forget about how blood flows and the pressure needed to pump and keep from back flow. There are many things that the heart can do and I personally do not think we can ever recreate anything that is as good or better than the original, the first Creator is kind of hard to beat.

http://www.sciam.com/article.cfm?id=not-just-a-pump&print=true