From: billphil@earthlink.net (Badwater Bill)
Newsgroups: rec.aviation.homebuilt
Subject: Re: Supplemental Oxygen
Date: Thu, 06 Jul 2000 15:00:49 GMT

>The spec for medical grade O2 allows significant moisture, but in
>practice all the O2 available (medical, welding, aviation, etc) is
>produced cryonically.  In fact, it all comes from the same big LO2
>tank.  That means there's no moisture in it at all.  In hospitals they
>add moisture to it before you breath it.


That's dead right.  There's NO moisture in any ABO (Aviation Breathing
Oxygen). And it all comes from the same source.  Welding oxygen is
ABO. It's all the same.

 If they put moisture in the steel bottle it would be highly corrosive
and the bottle would explode after awhile.  There is NO water in
ABO/welding oxygen etc.  The container is not designed for it.  The
last thing you would ever want to do is put water in a pressurized
oxygen bottle.  It would corrode a hole in the bottle in short order.

BWB

From: billphil@earthlink.net (Badwater Bill)
Newsgroups: rec.aviation.homebuilt
Subject: This might save your life if you use Oxygen and fly High
Date: Mon, 21 Aug 2000 03:00:17 GMT

Here's something that might help somebody.  I think the best portable
oxygen system on the market today is a "demand" based system with a
nose cannula and a small, lightweight Kevlar or fiberglass woven
aluminum tank.  I have one.  It's expensive but it's worth it.  The
tank is about $800 and the demand system is about $500 if I recall
correctly.  Mountain High Equipment and Supply Company (Ric Lee)
supplies my system.  The electronic "Black Box" part of the system
that supplies oxygen on demand is called an "Electronic 'Pulse-Demand'
Oxygen Delivery System" (EDS).

How it works is that it senses the pressure through a nose cannula
when you breath out and stop the exhale phase of the breath.  Just at
that point as you begin to breath in, pressure decreases in the nose
cannula and you get a pulse of oxygen.  In this way, that oxygen rich
pulse (at the beginning of the tidal breath cycle) goes deep into the
pulmonary section of the lung for good blood contact and subsequent
diffusion into the bloodstream.  The surface area of your alveoli sacs
is about that of a football field.  So, anything you pump into the
deep pulmonary section of the lung is essentially making direct blood
contact.  This "pulse" of oxygen is delivered in time at exactly the
instant you change the tidal cycle, i.e., you begin to breath in.  In
that way, the oxygen rich air goes deep into the lung.  As you breath
in, that pulse is only a fraction of the time of the entire intake
cycle of the breath.  Therefore, the other fraction of oxygen-poor air
is air that fills the volume of the tracheal bronchial region and
nasal pharyngeal region (just pipes).  Although this volume is quite
large, it is really wasted space for partial pressure diffusion across
the critical membrane of the pulmonary system which is the deep
section, i.e. alveoli sacs.

In this way, this system uses about one tenth the oxygen required by a
constant flow system to maintain proper blood saturation at high
altitudes.  I have an oxy-pulse-o-meter which is a portable blood
spectrometer and can measure the "color" of your blood by the
reflection of the beam from a narrow band pass laser on any one of
your fingers. The optical spectral color of your blood is a direct
measurement of oxygen saturation.  This device too is an expensive
piece of equipment (about $500) but will read out the oxygen
saturation of you blood in percent. The EDS is battery powered and has
a long battery life when equipped with the correct 9 Volt energizer
battery.  At high altitudes when you are depending on this portable
oxygen system, that's a critical measurement that must be made
periodically.  I adjust the oxygen (time) pulse-width of the EDS to
accommodate my needs.  The system is set up for a standard man plus
some but I find that I get a bit hypoxic at my body mass unless I
crank it up a bit.

The problem I've had with this system is the battery.  What Ric Lee
has done is use a battery to energize a solenoid to open an in-line
spring loaded valve for the oxygen-pulse.  This is smart since the
time open is very small during the normal tidal cycle of a breath.
The other alternative is to have the solenoid energized all the time
until the person begins the breath cycle.  At that time it could
de-energize and open the oxygen circuit.  This is perfect for a
battery failure, since it remains open and flow continues.  However,
if this were the design basis, the battery would be energizing the
circuit more than 90% of the time and would run down ten times faster.

The problem with the system as designed (in my opinion) is:  When the
9 Volt battery runs down, the solenoid is stuck closed and you get no
oxygen.  This has happened to me twice at high altitudes (above 16,000
msl).  I do usually carry an extra battery but find that in IMC
without an autopilot, changing that battery while becoming hypoxic is
quite a task.  I also have an extra port on the manifold out of the
bottle so I can plug in another constant flow cannula.  But, this is
cumbersome.  It requires a completely different cannula with a flow
rate meter and it takes up a lot of space to carry.

I spent the weekend with Ric last week and told him of my problem.
What I want is to carry NO extra equipment and have a fail safe
alternative.    I thought of one way around this and I've modified  my
system to accommodate my problem.  Essentially I've modified a $1500
system for less than one dollar.  In fact I think it was less that 50
cents.

Before we go any further, go look at these photos I took today of my
mod.

http://home.earthlink.net/~billphil/wsnC1AD.html

What I did was go to my local sprinkler supply house and buy two ¼
inch "T's" and one ¼ inch bubbler valve.  I bypassed that EDS box with
an analog valve (bubbler valve).  So, when the battery fails, all I
have to do is turn on (adjust) a small valve and go into a constant
flow mode.  Depending on the bottle content, that may last me for many
more hours and allow me to complete a flight with complete safety.
The first thought is "what is the flow rate and how do you control
it?"  I control it with the oxy-pulse-o-meter which reads out in
percent oxygen saturation of my hemoglobin.  As long as I keep my
percent saturation above the 90% mark, I can function just fine and
have no hypoxic effects.

I find that I begin to lose thought capacity below 90% saturation.  I
get nervous, apprehensive and fidgety in the cockpit.  Everyone reacts
to hypoxia in a different manner.  I'm fortunate that I have a
mechanism to become aware of hypoxia in the cockpit and can change my
oxygen intake appropriately.

There are a few of you out there who have purchased Ric's system.  I
modified my system in less than ten minutes this afternoon using
plastic hardware.  This, of course is not durable over the long term
and will present other problems such as easy breakage.  I have
requested that Ric provide me with stainless steel "T's" and a metal
valve.  However, a simple motorcycle in-line fuel valve would work
fine, is lightweight and durable.  My problem is locating the metal
"T's" so I used sprinkler parts.

I would like to say too, that Ric's system has an audible alarm.  If
you turn on your oxygen system on the ground before you crank up and
the battery is low, you'll hear that alarm.  It is not loud enough to
hear in my RV-6 in flight so a good pre flight check on that system is
to turn it on and see if it functions properly before you crank up.
Ric tells me that the alarm sounds with 2 hours of battery-life left.
Many of my flights are longer than that.  So, during pre flight, I
would not detect a low battery condition alarm  in all cases.  The
bypass is essential for my mode of operation.  I've been stuck twice
now without it and it's a simple mod.

The ability to control the flow manually in an analog mode is
essential for any pilot in a run-down battery condition.  The
oxy-pulse-o-meter is a perfect way to monitor your physiology so there
is no guessing at what your blood saturation is.

I know at least three of you who have this system.  Until Ric comes up
with good solid long-term metal parts to bypass this EDS box, I urge
you modify your systems appropriately if you use them at high
altitudes and especially at high altitudes in IMC or commercially.
Keep in mind however that the plastic parts can break easily.  What we
really need are the metal parts and I feel they are coming soon,
thanks to Ric.

BWB

From: billphil@earthlink.net (Badwater Bill)
Newsgroups: rec.aviation.homebuilt
Subject: Re: This might save your life if you use Oxygen and fly High
Date: Mon, 21 Aug 2000 20:21:27 GMT

On Mon, 21 Aug 2000 16:08:29 GMT, vintageav@eudoramail.com (O-ring
Seals) wrote:

>On Mon, 21 Aug 2000 03:00:17 GMT, billphil@earthlink.net (Badwater
>Bill) wrote:
>
>I think that Bill may have implied this, but did not come right out
>and say it.  Be sure that any valves and fittings that you use are
>compatable with oxygen service.  Do not, for instance, use some type
>of a valve that is lubricated with grease.
>
>Just a thought from a chemist.
>
>O-ring Seals

Good point "O"  grease can spontaneously combust in a pure oxygen
atmosphere.  Be careful with pure oxygen on all occastions.

BWB

From: "Bob Chilcoat" <viewptmd@erolREMOVEs.com>
Newsgroups: rec.aviation.homebuilt
Subject: Re: This might save your life if you use Oxygen and fly High
Date: Tue, 22 Aug 2000 08:32:19 -0400

Years ago the navy was conducting tests in 100% oxygen environments in an
altitude chamber.  One of the light fixtures popped and the bakelite light
socket started to burn while a number of people were in the chamber.  One of
the men tried to snuff the fire with a towel, which promptly started
burning, too.  He then tried to pat out this new fire with his hands.  His
HANDS caught fire (presumably the grease in his skin started it).
Fortunately, about this time, the technicians got the chamber open and were
able to get inside with fire extiguishers.  He was badly burned, but
survived.  This was in a report issued after the Apollo 1 capsule fire on
the problems of high oxygen partial pressure atmospheres.  Real scary.

Bob

"Dave Hyde" <nauga@brick.net> wrote in message
news:39A1E69E.C273C7B@brick.net...
> scott gardner wrote:
>
> > There was a thread on RAR a while back about a 206 helicopter down
> > in Oz that burned to the ground from a commercial fitting that was
> > plumbed into the airmedical O2 system.
>
> There was an article in the Navy's aviation safety magazine, "Approach"
> a few years back about an A-6 pilot who's petroleum-based-hair-gelled
> 'do caught on fire when he vented his O2 mask under his helmet.  Titled,
> appropriately, "Helmet Fire."
>
> Funny article, scary idea.
>
> Dave 'redhead' Hyde
> nauga@brick.net

From: billphil@earthlink.net (Badwater Bill)
Newsgroups: rec.aviation.homebuilt
Subject: Re: This might save your life if you use Oxygen and fly High
Date: Tue, 22 Aug 2000 14:18:37 GMT

On Tue, 22 Aug 2000 08:32:19 -0400, "Bob Chilcoat"
<viewptmd@erolREMOVEs.com> wrote:

>Years ago the navy was conducting tests in 100% oxygen environments in an
>altitude chamber.  One of the light fixtures popped and the bakelite light
>socket started to burn while a number of people were in the chamber.  One of
>the men tried to snuff the fire with a towel, which promptly started
>burning, too.  He then tried to pat out this new fire with his hands.  His
>HANDS caught fire (presumably the grease in his skin started it).
>Fortunately, about this time, the technicians got the chamber open and were
>able to get inside with fire extiguishers.  He was badly burned, but
>survived.  This was in a report issued after the Apollo 1 capsule fire on
>the problems of high oxygen partial pressure atmospheres.  Real scary.
>
>Bob

I don't know how many of you know about hyperbaric chambers but they
were used at the U of W medical school to treat cancer patients.  Most
tumors are hypoxic and the cells will die if you oxygenate them.  So,
they put people in high pressure pure oxygen chambers to "oxygenate"
the solid tumors.  Many burned to death in various accidents and the
treatment was abandoned.

BWB