Posting in Cancer
A new artificial heart can keep you alive - without a pulse.
Can human physiology be supported without a pulse?
Normally, no -- at least in regard to our common definition of death. However, if you are one of the select few that have been equipped with new artificial heart technology developed by the Texas Heart Institute, then blood flow can be pumped around your body -- without the need for a pulse.
We do not actually need a pulse to stay alive, we just require a means to ensure that bloody flow is continually circulated through the body. Doctors Bud Frazier and Billy Cohn created a new, continuous-flow artificial heart based on these principles, the continuous-flow left ventricular assist device (VLAD).
By using two turbines to replace the muscle of the heart, the system keeps blood moving continually by mimicking the heart's pumping rhythm, without recreating the pulse.
Although it in no way looks like a natural organ, the device has so far been tested on 50 calves, and its first human subject, Craig Lewis, can be considered a success -- at the least as a temporary measure. After being given a maximum of 12 hours to live due to a plethora of medical conditions, the surgery was performed to take out his original heart and replace it with the 10,000 RPM artificial alternative.
Within 48 hours, Lewis was able to sit up, speak, and even sketched. Although he passed away 5 weeks later, the causes are reportedly to have been due to his original conditions -- and the artificial device would never have been able to eradicate these issues, but it did allow him to live longer and say his goodbyes.
Since Lewis, several other patients have been fitted with the devices.
Cohn and Frazier's continuous-flow left ventricular assist device was previously placed in a calf named Meeko, who lived on to lead a normal life after having his heart taken out and replaced with the turbines. The surgery was performed by cutting the heart free, sewing collars of rubberized Dacron onto the atria, and then connecting the turbines on to the collars before activation.
Creating an artificial heart has been difficult up until now, as many metal and plastic experiments have resulted in the wearing out of material, and an inability to beat -- mimicking the human pulse -- for more than 18 months.
Currently, there are other developments within artificial heart development -- including the 'Total Artificial Heart' made by Arizona-based SynCardia Systems Inc., which replaces ventricles and a number of valves instead of taking out the entire organ. However, it does require toting around a 12 pound external engine to power the heart, and according to the second patient to receive the operation, John Martino, it is extremely loud -- and is only a measure for patients who are waiting for a transplant rather than a permanent solution.
This new VLAD technology has the potential to help patients with conditions such as terminal heart disease in the future, and as the scientists themselves say, may mean we are a step closer to a 'perfect' artificial heart.
Cohn tells Popular Science that: "I think we're on the verge, right now, of solving the artificial-heart problem for good. All we had to do was get rid of the pulse."
For more information, view the video below:
Thumbnail credit: Anais GÃmez-C
- Ready for cast removal? Implantable sensor monitors healing bones
- The Morning Briefing: NHS reforms, free HIV care, doctors strike
- Unapproved foreign imports to ease cancer drug shortage
- On the Doctor's orders: Prescribed smartphone apps
- Should a company be able to patent your genes?
Mar 6, 2012
"Brittle" veins or death, hmmm...tough one. Get off your armchair doc, I hear your microwave beeping.
The regular pulsing of our heartbeats has another, CRITICAL role: keeping our blood vessels flexible. Really, folks, this has been known for years. And if you don't see the harm, in having a brittle circulatory system, I have a whole carload of organ transplants to sell you ... because you'll need them, before you are done.
And if you were found unconscious somewhere, you would be toe-tagged as dead and hauled to the morgue.....
So, let me get this straight... They take away your pulse, but keep you alive, and the device they use to do it is named after the person that is supposed to be the origin of the vampire mythos. Was that intentional?
Doesn't the human body have a system of (for lack of a better term) 'check valves' within the veins that prevent blood back-flow? How well does the circulatory system handle the lack of pulsation given by a normal heart rhythm? Are not veins, etc., dependent upon this elasticity to keep them healthy? Does the pulse help to prevent plaque buildup within the circulation system (as compared to constant flow)? I am definitely NOT in the medical profession but I am curious about whether or not it can be deemed 'safe' to fool around with Gods original design. The medical profession has many times thought and idea was revolutionary and better than the original only to be later proven wrong (consider drug/medications here primarily).
Doesn't ex VP Dick Cheney have an artificial heart? I had read that he was debating whether to try to get a transplant or just keep the artificial heart.
like becoming a vampire, having a pulseless heart is just a tad more than being dead...but does it actually beat dying? does our fear of passing away justify this? on top of marinechief's comment re one-way venal valves and vessel-wall elasticity, i would like to add that there might be resons for the blood system's rhythmic action that science does not yet see nor understand. embryonic pulse, for one, precedes the appearance of the embryonic heart.
Just because God didn't invent a better system doesn't mean the we can't. Just look at our tail bones how silly they are. Now a good sturdy tail would be very handy in many situations. And what did we get? Something that only shows up on an x-ray. As for 'safe' and the long term effects; that's why they are testing it. But hands up all those who wants to die of a bad hearth. Anybody?? I can't see Your hands.
isn't the best there is. Then why haven't man been able to duplicate it, or make something better?? Oh thats right, he can't.