From:	Glenn Robertson <Glenn.Robertson@***.EDU>
Subject:	Re: Underwater breathing
Date:	Sat, 30 Nov 1996 08:41:01 -0700

> > Just a thought use a internal air tank (cyber) then fill the lungs with liquid
> > and then go diving, then use the air in the tank to reinflate your lungs???
> > (flame away I am not quite consious and what I just said might be a loada...)
> > >Shaman
> > Tim (ntoo)
> >
> I thought about this. However, let's envisage this from a physiological
> point of view. The alveolar of the lungs (where gas exchange takes place
> between air and blood) expand against resistance and surface tension. It
> uses surfactant to reduce this and also (most importantly) allow small
> alveoli to reinflate before bloating up the larger ones. Removal of
> surfactant with liquids has a devastating effect. So, in order to
> include this idea, we have to incorporate a surfactant excreting
> cyberware as well.

Ahh, but there already is real liquid mediums to aid breathing. Liquid
Perfluorocarbon Ventilation. Check it out. Being a liquid, the lungs
are still inflated, they don't have to collapse. It was primarily used
in premature infants, but recently it has undergone study for application
for adults as well. Just thought I'd let you know, since I just read
about it again last night at work --- I am a registered respiratory
therapist and it was hanging in our break room. :)


>
> The other problem is the gas mixture. From memory (and name) the O2 gas
> tank is pure O2.
No, it doesn't have to be. You can put any mix you want in there. At
the hospital we have varying mixes. Mostly pure oxygen tanks, granted,
but we have two different heliox varieties, various mixes of regular air
and anesthetic, and for machinery even tanks with oxygen, carbon dioxide,
and nitrogen. So, you can put any gas mix you like in a tank.


> This has serious ramifications if we were to reinflate
> with just O2. Hence, a better "air" mixture is needed. If reinflating at
> sea level, then an air mixture can be used. If in an underwater city or
> something, then the pressure would require another mixture, to compensate
> for the partial pressure of O2. So a helium/oxygen mix could be used.

There is nothing wrong with using pure oxygen in tanks as I recall, unless
you are an infant whereby you can get Retrolental Fibroplasia (RLF) and go
blind like Stevie Wonder. Afterall, many patients at the hospital get
pure 100% oxygen. Also, some patients on ventilators get 100% oxygen,
which is important because they don't get any outside air entrainment.
Oxygen doesn't cause alveolar collapse.

Just my respiratory two cents.

Glenn