Re: [PSUBS-MAILIST] Liquid Ventilation

[CWall@swri.edu]

Yeah, and artificial "lungs" - or rather, "gills" have been built using
membrane gas separation technology....but that still leaves gas-filled spaces
in the human body that are subject to "squeeze".  IOWs, you probably still want
 to flood the lungs of a diver.

I do know that adult humans have "breathed" using this perfusion technique, but
 they only had one lung flooded- they just lay on their side and ran tubes down
 their throats- not very comfortable, I'm guessing.  Then, of course, there's
that pesky tendency to try to breathe anyway, which is why you'd need a curare
drip to suppress reflexive movements of the diaphragm.  (Obviously they didn't
administer this to the human experimental patients- I'm not sure if they did
for the premie baboons.)

Have you ever inhaled a solid slug of water?  I have, a couple of times.  Gawd
what a shock!
I think I'd need to be knocked out before the transition- otherwise I don't
think I could help but fight it.   (Although it's mostly psychological, like a
fear of falling....I suppose if  you can jump out of airplanes, you could get
used to intentional drowning.....)

Plumbing another organ into the human body, as you suggest, brings us closer to
 cyborg status and I do know that animal research has just begun to broach this
 topic- but the opportunity for infection is very high, naturally, and I think
it'll be awhile before that would be used for anything other than desperate
situations.  But I'm sure it'll happen eventually- I mean, we have precedent
now, with peritoneal dialysis, for instance. In fact, you could probably
combine the two.   But It's like walking a tightrope  three times a day for
those people, and eventually they get infected and lose patency.   Doing
aseptic plumbing in a wet environment is the stuff of nightmares- we'd have to
get to a technology that could interface the artifical components in a manner
that was compatible with a working immune system- flesh and steel just don't
grow together naturally.

Craig Wall   
---------- Original Text ----------

From: "Nathanael Henderson" <jude@pconline.com>, on 11/29/00 8:52 PM:
To: Incognito2@CTC@SwRI26[<personal_submersibles@psubs.org>]


>   Under pressure, things get better.   It may be possible for deep divers to
> use something like this....but the transition on and off seem likely to be,
> well....problematic.

    I just about gagged when they 'drown' the hard hat diver in "The
Abyss" in the liquid breathing medium.   It would take a determined person
to go through that concious, although perhaps the sensation wouldn't be
all that bad once the novelty wore off.  :-)

>   Who knows? It bears watching, but IMHO- don't get your hopes up. 

    It sounds like a lot of obstacles to overcome...for an off-the-shelf
human.  :-)   Perhaps some sort of synthetic lung...a bypass machine?
Replace the lungs with something more structurally suited to fluid/fluid
gas exchange and feed that with oxygenated and CO2 scrubbed fluid from an
external pack....    OK, that's pretty radical to go diving...but can you
imagine a casual dive without a sub to, say, 3,000 feet, then coming back
without decompression?    I wouldn't be surprised if you found some
saturation divers that were game...but of course, they're insane to begin
with.  :-)