backtop


Print 63 comment(s) - last by Boze.. on Mar 7 at 12:59 PM


Artificial heart  (Source: popsci.com)
Currently, 50 calves and three humans are using the pump, which completely replaces their natural hearts

Researchers from the Texas Heart Institute have successfully replaced the human heart with a 10,000-RPM artificial pump, which leaves its patients with absolutely no pulse.

Popular Science described the artificial heart, which doesn't resemble an organic heart by any means. Currently, 50 calves and three humans are using the pump, which completely replaces their natural hearts.

Drs. O.H. "Bud" Frazier and Billy Cohn of the Texas Heart Institute in Houston are the creators of the artificial pump. It is able to fully replace the heart and even provide a continuous flow of blood throughout the body -- all without having to recreate a pulse.

Creating an artificial heart has been difficult up until now. Many have tried to make a metal and plastic heart that is capable of beating, but many were unable to continuously beat beyond an 18-month period. Also, metal and plastic have many limitations, such as the requirement of an air compressor outside of the body where a hose through the skin allows the compressor to fill a balloon inside a chamber, which pushes blood to the lungs. The other balloon inflates and deflates in an alternating pattern with the other to recreate the heart's beating rhythm. This is exactly what the Jarvik-7 -- the first machine to replace the human heart -- did in 1982.

There have been other devices, such as the HeartMate ll, which is an Archimedes' screw that assists failing hearts with magnets implanted in the axle and an electric coil in its case where a charge makes its way around the coil, moving the screw at 8,000 to 12,000 RPMs. The axle spins on a synthetic-ruby bearing, which is lubricated by blood, and it's all connected to a portable battery. But the HeartMate ll can't replace the heart entirely.

Cohn and Frazier's continuous-flow left ventricular assist device (LVAD), however, can replace the heart and doesn't require a compressor because the researchers discovered that recreating the pulse wasn't necessary. The trickiest part to creating an artificial heart was recreating the pulse, but Cohn and Frazier found that just using a continuous-flow heart solved the issue of longevity, which is the main issue. One of the turbines used in the artificial heart has been running in a lab continuously for eight years, and it runs on a small battery that the patient can easily carry on their shoulder.

Cohn and Frazier described a recent process where the LVAD was placed in a calf named Meeko, who lived on to lead a normal life. However, he didn't have a pulse whatsoever, which didn't seem to be a problem. Cohn performed the surgery by peeling tissue from around the heart and allowed a heart-lung machine to take over. The heart was cut free, and continued to beat outside of the body. Cohn then sewed collars of rubberized Dacron onto the atria. He then lifted the turbines from a dish of saline with the dolly dresses dangling from them. The dolly dresses were sewed onto the collars, and the turbines were activated.

“That’s what heart surgery is,” said Cohn. “It’s a script. To you, it probably looked like I was just sewing those collars into Meeko’s chest any old way. But every motion was planned, tested, practiced. Turn my hand eight degrees and poke the needle through; swivel my hand back 22 degrees and draw the needle up four inches; turn my hand back just so and bring it to the left a half inch: a precise number of stitches, pulled just so tight and no tighter. What heart surgery takes is remembering an incredibly long and complicated script and following it exactly, step by step.”

Source: PopSci



Comments     Threshold


This article is over a month old, voting and posting comments is disabled

RE: Blood pressure?
By TSS on 3/6/2012 9:50:15 AM , Rating: 2
Eh kind of. Remember us humans have a minimum heart "beats per minute" before our muscles stop working and a maximum before veins start to burst, but the range in between is incredible. Human hearts can beat between 20 and 200 beats per minute and the human will still be alive.

You could put in 3 smaller motors. 2 spinning at the same time would provide enough pressure for regular day use (office work, enjoying watching TV, reading a book etc). When you need to run or otherwise use alot of energy, the 3rd motor kicks in, your blood pressure rises, muscles get more oxygenated = more energy.

Likewise, when you go to bed one of the motors can spin down to half speed or turn off entirely, to lower blood pressure and enter a "relaxed" state.

In case of 1 motor failing, the 2nd motor would automatically kick in as a backup untill the faulty one can be replaced. You wouldn't be able to run, no. But you would still be able to walk to the hospital. Even in the event 2 motors fails, the 3rd one would be enough power to keep you alive while the ambulance comes to pick you up.

There's never be a danger of too much blood pressure or too little blood pressure - Simply set a minimum and maximum speed those things can rotate at. And ofcourse, hardcode it into the bloody thing so that we don't get any issues about "hacking" or whatnot.

IMO it's a better sollution then our current natural hearts. It might run for 80 years but if it ever fails it's instantly game over. You won't even be able to call for help unless you've got like a 1 button alarm or something.


"This is about the Internet.  Everything on the Internet is encrypted. This is not a BlackBerry-only issue. If they can't deal with the Internet, they should shut it off." -- RIM co-CEO Michael Lazaridis














botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki