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So, one of the problems with artificial hearts is that it's
not
good to have non-natural materials in contact with blood
for long periods of time. Clotting and grot-deposition is
a
problem, as is the junction between natural and
artificial
components.
How about a non-contact artificial
heart? The surgeon
would first dissect the aorta (or another large vessel)
free
of surrounding tissue, but without cutting it.
The artificial pump would consist of a series of inflatable
(with air or liquid) cuffs which wrap around the aorta.
Individual cuffs can be inflated squeezing the aorta) or
deflated. By inflating the cuffs in sequence, from one
end
to the other, you'd create a peristaltic wave travelling
down the aorta, pumping the blood along.
The blood would not come into contact with anything
non-
natural; there is no blood-tight connection to be made
anywhere; and the mechanical action should be gentle
on
the blood cells.
One hose pump type
http://www.flomotio.../4001V-Pump-800.jpg
There exist pumps that in theory could directly affect a major artery, without cutting into it. The link just shows one variation on the theme. [Vernon, Sep 01 2015]
Alternative artificial heart placement
alternative_20artif...20heart_20placement
related [Voice, Sep 01 2015]
US 8016739
https://www.google....u/patents/US8016739
an aortic compression means which may be fully implanatable, a fluid reservoir and a pump means adapted to pump a fluid from the reservoir to the aortic compression means [xaviergisz, Sep 01 2015]
Aortic counterpulsation: C-pulse and other devices for cardiac support.
http://www.ncbi.nlm...gov/pubmed/24554288
C-Pulse is a nonblood-contacting counterpulsation using an inflatable cuff around the ascending aorta, extra-aortic balloon (EAB) counterpulsation device. [xaviergisz, Sep 01 2015]
[link]
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p.s. - with the right software, it might double as an
implantable didgeridoo. |
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Would you remove the (presumably non-functional) real heart? What would be interesting about this is the potential for several mini-hearts situated around the body. Then, if you are doing something that subjects you to high g-forces (e.g. fighter jet pilot, astronaut) your auxiliary neck-based heart might be used to maintain blood pressure to your brain and prevent you blacking out. Or if you'd accidentally bought a pair of shoes that were slightly too big, a pair of ankle-based hearts could be used to slightly inflate your feet to make the shoes a perfect fit. |
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The continuous aspect is something which current left ventricular assist devices do. But they are in contact with blood. |
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I worry that the aorta might not be that squeezable. If there is plaque then squeezing could be bad. |
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I thought I had read about a deal where the latissimus dorsi muscle was taken loose and wrapped around the heart, then stimulated with a pacemaker to squeeze the lazy heart from the outside. Or maybe I dreamed that? |
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//implantable didgeridoo// |
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So, your heart murmur goes wwwwawwwwawwwwawwwwwwwwwww ? |
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//Would you remove the (presumably non-
functional) real heart?// |
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It would depend. If it weren't blocking flow (and
might even be contributing something), maybe it
would be left in. |
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//several mini-hearts situated around the body//
Yes, although they'd all have to be powered
somehow. |
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//the aorta might not be that squeezable. If there
is plaque then squeezing could be bad. //
True. I guess you might have to ream it out first... |
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//I thought I had read about a deal where the
latissimus dorsi muscle // I half-remember that
also, so it may be true. Not sure that skeletal
muscle is ideal for regular, repeated contractions,
but maybe. |
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How about using the uterus! This for people who have uteri. It is strong. It is smooth. It can squeeze at least as strongly as the heart. If your heart is that bad you should not be getting pregnant. I would rather get added value out of my uterus then lose my latissimus. |
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Holy shit Max, this is brilliant. |
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Like I posted after your other posting of this idea, it's
basically like having a built in CPR compression system. |
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Has anybody ever looked into this? I'd do a quick patent
search, drop a hundred bucks on a provisional utility
patent then shop the idea to a couple of your closest
heart surgeon friends. |
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This is really damned clever. |
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Not sure of the placement around the aorta though, I'd
just stick a bag outside
each chamber of the heart rather than messing with
peristaltic squeezing of the actual tubes. Then you've got
your built in CPR device rather than messing around with
little tubes where you might damage the valves. |
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Compressing just the various heart chambers in correct
sync would be the least obtrusive way to do this I'd think. |
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//Holy shit Max, this is brilliant. // Awww,
shucks. |
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//Like I posted after your other posting of this idea//
I what? Am I having a senior moment? |
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//stick a bag outside each chamber of the heart//
Actually that is a much better idea (assuming that
your valves are in working order). |
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Has nobody ever thought of this before? It seems like one
of
those ideas that's such a no brainer, but I guess you could
say that about any good idea. |
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As far as I know, research into fake hearts has stalled out
due to the problems you mentioned. I believe patient
tissue
regeneration of parts is the next thing they're looking at,
but something like this in the meantime... |
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You could just have various bulbs placed around the
heart or a jacket, sleve or multi chambered band around
the heart that has chambers that expand or contract in
sync to squeeze or release the chambers as necessary. |
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Did I dream it or have surgeons manually pumped hearts
during surgery to keep the patient alive? I mean actually
grabbed the heart and squeezed it like a rubber bulb to
pump the blood through? |
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//How about using the uterus! This for people who have
uteri. It is strong. It is smooth. It can squeeze at least as
strongly as the heart.// |
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No, Uterus is specialized for long slow contractions.
Skeletal muscle is specialized for maximum force per
size, if you attach them by their ends, they'll happily be
so strong they'll tear themselves apart. Cardiac muscle is
the one you want for ongoing contraction-relaxation
cycles. |
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I'm not sure how the aorta would respond to repeated
squeeze-relax cycles, I think that might be more stress
than the gentle internal bulge it normally gets. |
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I thought a while ago that replacing the heart with a more
continuous pump would be a good way of getting total blood
flow up while reducing the pulsing. I reasoned that if the
whole system is set up to handle peak pulse pressure, you
can run it constantly at 2/3rds that, get much better total
flow and preserve the system somewhat. I'll probably
destroy some biological regulation mechanism though, and
everything will be ruined. |
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//run it constantly at 2/3rds that, get much better
total flow and preserve the system somewhat.// |
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That is actually a good idea. Smoothing out the
flow
would probably reduce the incidence of strokes
caused by burst cerebral vessels. |
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On the other
hand, maybe the peak flow helps to stop crud from
building up. It's a bit like when they tell you that
drinking four bottles of vodka one a fortnight helps
to flush out your liver. At least I think that's what
they told me. |
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When I post an idea and it's universally ignored, (or even
boned and marked for deletion which has happened more
than once) and then someone posts an almost duplicate
idea which is showered in accolades and buns I realize the
perceived quality of the idea isn't the idea itself but a
combination of a particular style of persuasive writing
(which I'll never be able
to understand) and a social factor (which I'll also never
understand). It makes me feel... something. |
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[Voice], kudos to you for coming up with something
similar, and four years earlier. |
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As regards writing style, I can only comment that
I've applied for many research grants in my time.
After getting a few of those favourably reviewed, a
man stands a fair chance of getting any kind of
tombollockry past the more discerning minds of
the HB. |
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Oh, and plus I bribed [doc]. |
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//strokes caused by burst cerebral vessel// |
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Aneurysms. You really don't want to get the treatments
for those two mixed up. |
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//On the other hand, maybe the peak flow helps to stop
crud from building up.// |
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Hmm, well the arterial walls have muscle that squeezes
back once it's stretched. Pulse smoothing and peristalsis
built in. If you plot aortic pressure vs pressure in a
peripheral artery you can see the latter stretched out.
Not sure about crud build up, but maybe the pulses are
necessary to get the fatter immune cells through the
smaller vessels, I'll ask the appropriate physiologist. |
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//drinking four bottles of vodka one a fortnight helps to
flush out your liver// |
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That constitutes binge drinking, which doctors don't like.
So drink the same every night, turn it into consistent
heavy drinking. I pretty sure the doctors will be fine with
that. |
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//consistent heavy drinking// |
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Good advice. At the moment, I'm following the
government's "Five-a-Day" advice most days. But,
increasingly, I'm finding that I tend to feel sober
between drinks. I guess that's a sign to step things
up a notch. |
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//Smoothing out the flow// |
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Is there the possibility of un-intended consequences with
such a radical change of fluid delivery? Do the pulses act
as
"flushes" to clear the pathways? Perhaps a smooth flow
would allow more buildup such as with sediment building
up
inside the curves of a river? |
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//When I post an idea and it's universally ignored, (or
even boned and marked for deletion...// |
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Well, you're in good company. Remember, Galileo, Lincoln
and that guy with the beard, what's-his-name,
were all
thrown in jail for saying the sun was flat or something.
Rest assured that history will accurately pay homage to
great minds eventually. |
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//Galileo, Lincoln and that guy with the beard,
what's-his-name, were all thrown in jail// |
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Salman Rushdie, I think. I am saddened when I
realise that I have never once been thrown in jail,
and I am now 53 years old. By the time Mozart was
my age he'd been dead for 22 years. |
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I figure I've missed my chance to gain immortality by
dying in my prime. I therefore plan to stick around
long enough to become an embarrassment to my
great grandchildren. |
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I'm at the age too where I'll get the occasional morbid
thoughts like "If
I get Alzheimer's and begin to lose my mind, I'll move to the
jungle with nothing but a
loincloth and a knife, spending my last days surviving on
wild game and dying like a man!" |
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Of course I'll probably just think I'm in the jungle as I run
around the park in a diaper chasing squirrels with a spoon. |
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//chasing squirrels with a spoon//
The squirrels would have nutcrackers, not spoons, shirley? |
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It feels familiar but I consider this a good idea. The peristalsis would have to very relative to the distance away from the heart to preserve the holistic health - the natural environment the extremities are use to. |
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As a side thought - I am sure the crud is heat dependent (the hot blooded factor). Probably there is some, enzyme resistant, molecular sticky factor too. |
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I wouldn't remove the nonfunctional real heart, as it's
secondary function is to serve as a junction box. |
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