Reduced Oxygen Breathing System for Training

**Dave Sutton** · 21st February 2008, 00:04

Got a new goodie at work that I wanted to share. This is a ROBD (Reduced Oxygen Breathing Device) designed to let pilots and flight attendants experience high altitude hypoxia at sea level. It's a nitrogen/oxygen continuous mixing system, and is used to feed hypoxic nitrox mixes into the flight simulators we run. Pilots are then asked to perform complex flight tasks while we reduce the PP02 of the gas, and their performance is documented on a recording system for debrief. We do the same thing withy flight attendants, as they need to know the symptoms also. Having access to the thing, I have found it VERY interesting to use with rebreather divers as well. Hypoxia symptoms are similar but not identical in every person, and it is important to know your own personal symptoms. Until this, we did actual hypobaric chamber training with the pressure reduced to 25,000 or 35,000 feet. This was great, but we could not ask people to do 'real world' piloting skill tests. Now we can.

I have couch-dived my rebreather students on a scrubber with the 02 solenoid off and me controling the manual add valve for years, in order to do hypoxia training. t's something that you need to do VERY carefully, but it has value. It is NOT a good idea to do in the water, and in fact one of our more highly esteemed members here, who will remain nameless, did this in a pool with a student and almost drowned him. NOT good.

In any event, this is a nice system, and ought to evoke a little thread on the deliberate, controlled, and supervised use of hypoxic gas training ON THE SURFACE for rebreather divers.

Photos show a cabin procedures trainer with the system in front. Note the pure nitrogen and 02 bottles behind it. The others show the system up close. Note the single 02 analizer (with high and low alarms) mounted on the mixing system. Could not help tossing in the last photo either... a grinning me sitting in a hypobaric chamber getting ready to go unconcious at 25,000 feet. Time of useful conciousness there is about 5 minutes. I do this once a year and it's great fun.

Dave

.

Retardboy · 21st February 2008, 00:24

Hi dude. Do you measure SpO2 when doing the hypoxic tests/chamber runs?
If so, at what value do people generally black out?
Although I dont dive breathers, I have been thinking of testing various hypoxic mixes (on dry land

) as I have access to equipment for monitoring SpO2. As you say, nice to know what it feels like.

Haavard

Edit: As there is an input for puls oximeter on the mixer I guess you do

Gobfish1 · 21st February 2008, 00:30

looks interesting Dave ,,

that photo of you , looks like you're sat waiting for you're washing ..

getting high at work ,, what a life

rchrds · 21st February 2008, 01:31

har har - are any of those guys young enough to still get physicals?

They wont let us in the deco chamber- our engines go hot and the hamsters croak before the pilots poop out in our machines!

Guess they got better uses for it...

diver1369 · 21st February 2008, 02:12

When I did TMx with Gregg Stanton, he has four bottles with regs rigged that the students get to breath from and then identify: O2, hypoxic, hyperoxic (but not pure O2) and hypercapnic. Its a real eye opener. We both ID'd them all four correctly. Gregg says most students do... This all happens on the surface, of course...

john

Quote: (Originally Posted by Dave Sutton)

Got a new goodie at work that I wanted to share. This is a ROBD (Reduced Oxygen Breathing Device) designed to let pilots and flight attendants experience high altitude hypoxia at sea level. It's a nitrogen/oxygen continuous mixing system, and is used to feed hypoxic nitrox mixes into the flight simulators we run. Pilots are then asked to perform complex flight tasks while we reduce the PP02 of the gas, and their performance is documented on a recording system for debrief. We do the same thing withy flight attendants, as they need to know the symptoms also. Having access to the thing, I have found it VERY interesting to use with rebreather divers as well. Hypoxia symptoms are similar but not identical in every person, and it is important to know your own personal symptoms. Until this, we did actual hypobaric chamber training with the pressure reduced to 25,000 or 35,000 feet. This was great, but we could not ask people to do 'real world' piloting skill tests. Now we can.

I have couch-dived my rebreather students on a scrubber with the 02 solenoid off and me controling the manual add valve for years, in order to do hypoxia training. t's something that you need to do VERY carefully, but it has value. It is NOT a good idea to do in the water, and in fact one of our more highly esteemed members here, who will remain nameless, did this in a pool with a student and almost drowned him. NOT good.

In any event, this is a nice system, and ought to evoke a little thread on the deliberate, controlled, and supervised use of hypoxic gas training ON THE SURFACE for rebreather divers.

Photos show a cabin procedures trainer with the system in front. Note the pure nitrogen and 02 bottles behind it. The others show the system up close. Note the single 02 analizer (with high and low alarms) mounted on the mixing system. Could not help tossing in the last photo either... a grinning me sitting in a hypobaric chamber getting ready to go unconcious at 25,000 feet. Time of useful conciousness there is about 5 minutes. I do this once a year and it's great fun.

Dave

.

Gene_Hobbs · 21st February 2008, 04:29

Chuck (designed and did first research) just started at Duke but already has a great plan for the next version of this system. It was designed and built at the Naval Aviation Medical Research Lab in Pensacola FL. The first version was built for them by the chamber at Duke over ten years ago. Great system, currently works off mass flow controllers.

RonMicjan · 21st February 2008, 04:53

cool setup, I know a few guys I would like to use that on...

Hmmm, got me thinking about blending up some OC mixes to put students on and have them do math problems and logic type tests.

Then of course there is that secret video of someone (who shall remain nameless) going hypoxic (during a controlled, monitored by a physician, test)on a CCR with the O2 turned off... If I recall, the lights went out at 8% O2 and 65% perfusion on the pulse oximeter.

Now what kind of Moron would volunteer for a test like that?

Eliot Danner · 21st March 2008, 17:07

Dave - you have all of the coolest toys...

Sutty · 21st March 2008, 19:04

I did an explosive decompression from 8000' to 25000' in about 3 seconds in a hypobaric chamber a few years ago, then took off masks to breathe chamber air and was pretty hypoxic after 2-3 mins, couldn't write properly, pulse oximetry 56%, but still with it enough to put my mask back on when told to.
I've also breathed from my rebreather with O2 off, sitting at home (with a briefed resuscitation officer/ex-intensive care nurse sitting next to me!). Didn't have pulse oximetry that time but got rather blue and was pretty dizzy by the time my kiss displays read 0.05! - still good enough to appreciate the blueness and to take mouthpiece out though.
Interestingly my symptoms were not particularly consistent in the two instances, and I have heard anecdotally that hypoxia symptoms can vary from episode to episode which may reduce the value of the exercise.
If you are going to do anything like this please do so with appropriate trained and briefed support/supervision.

**Dave Sutton** · 21st March 2008, 21:13

Quote: (Originally Posted by Sutty)

Interestingly my symptoms were not particularly consistent in the two instances, and I have heard anecdotally that hypoxia symptoms can vary from episode to episode which may reduce the value of the exercise.

Hi Sutty, good post. RAF Chamber?

What the med guys at the military chamber here teach us is that you never loose a symptom from episode to episode, but may add new ones. If you had a visual disturbance the first time you ought to keep that symptom for life, but might notice new ones in addition to the first one later.

Interestingly enough, my first symptom is the sensation of heat, or bright sunlight, on the back of my head. This and a glare sensation of bright light, which is actually the loss of vision due to retinal hypoxia being perceived as a loss of vision due to bright light. The knowlage learned in the chamber saved my ass once, as you will read here if interested (the hypoxia part is about halfway thru):

Untitled

In the USA, chamber rides are free for licensed pilots. The FAA runs the program and the USAF does the rides. All you need to do to become a licensed pilot is to go to an aviation medical examiner and obtain a 3rd class medical and student pilot license. You are instantly a licenced pilot and can then go to the chamber. It's one of the last "Good Deals" available.

Dave

.

21st February 2008, 00:24	#2 (permalink)
Retardboy New Member Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Mar 2006 Location: Norway Posts: 16	Re: Reduced Oxygen Breathing System for Training Hi dude. Do you measure SpO2 when doing the hypoxic tests/chamber runs? If so, at what value do people generally black out? Although I dont dive breathers, I have been thinking of testing various hypoxic mixes (on dry land) as I have access to equipment for monitoring SpO2. As you say, nice to know what it feels like. Haavard Edit: As there is an input for puls oximeter on the mixer I guess you do Last edited by Retardboy : 21st February 2008 at 00:26.
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21st February 2008, 00:30	#3 (permalink)
Gobfish1 RBW Member Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Classic Inspiration Vision Evolution Join Date: Apr 2005 Location: Manchester UK Posts: 397	Re: Reduced Oxygen Breathing System for Training looks interesting Dave ,, that photo of you , looks like you're sat waiting for you're washing .. getting high at work ,, what a life __________________ Steve G Apparently not the only gay diver in the village http://drinkingliberally.org/blogs/o...nzee-glock.gif http://www.scubatunes.com/audio/vol01/mp3/HiTech.mp3 Last edited by Gobfish1 : 21st February 2008 at 00:34.
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21st February 2008, 01:31	#4 (permalink)
rchrds New Member Current Rebreather/s: Other CCR RB80 / Clone Home Build Other Rebreather/s: Other CCR RB80 / Clone Home Build Join Date: Feb 2005 Location: Clarksville, TN Posts: 42	Re: Reduced Oxygen Breathing System for Training har har - are any of those guys young enough to still get physicals? They wont let us in the deco chamber- our engines go hot and the hamsters croak before the pilots poop out in our machines! Guess they got better uses for it...
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21st February 2008, 02:12	#5 (permalink)
diver1369 RBW Member Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Sep 2005 Location: Maryland, USA Posts: 87	Re: Reduced Oxygen Breathing System for Training When I did TMx with Gregg Stanton, he has four bottles with regs rigged that the students get to breath from and then identify: O2, hypoxic, hyperoxic (but not pure O2) and hypercapnic. Its a real eye opener. We both ID'd them all four correctly. Gregg says most students do... This all happens on the surface, of course... john Quote: (Originally Posted by Dave Sutton) Got a new goodie at work that I wanted to share. This is a ROBD (Reduced Oxygen Breathing Device) designed to let pilots and flight attendants experience high altitude hypoxia at sea level. It's a nitrogen/oxygen continuous mixing system, and is used to feed hypoxic nitrox mixes into the flight simulators we run. Pilots are then asked to perform complex flight tasks while we reduce the PP02 of the gas, and their performance is documented on a recording system for debrief. We do the same thing withy flight attendants, as they need to know the symptoms also. Having access to the thing, I have found it VERY interesting to use with rebreather divers as well. Hypoxia symptoms are similar but not identical in every person, and it is important to know your own personal symptoms. Until this, we did actual hypobaric chamber training with the pressure reduced to 25,000 or 35,000 feet. This was great, but we could not ask people to do 'real world' piloting skill tests. Now we can. I have couch-dived my rebreather students on a scrubber with the 02 solenoid off and me controling the manual add valve for years, in order to do hypoxia training. t's something that you need to do VERY carefully, but it has value. It is NOT a good idea to do in the water, and in fact one of our more highly esteemed members here, who will remain nameless, did this in a pool with a student and almost drowned him. NOT good. In any event, this is a nice system, and ought to evoke a little thread on the deliberate, controlled, and supervised use of hypoxic gas training ON THE SURFACE for rebreather divers. Photos show a cabin procedures trainer with the system in front. Note the pure nitrogen and 02 bottles behind it. The others show the system up close. Note the single 02 analizer (with high and low alarms) mounted on the mixing system. Could not help tossing in the last photo either... a grinning me sitting in a hypobaric chamber getting ready to go unconcious at 25,000 feet. Time of useful conciousness there is about 5 minutes. I do this once a year and it's great fun. Dave . Last edited by diver1369 : 21st February 2008 at 02:14. Reason: clarify surface issue
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21st February 2008, 04:29	#6 (permalink)
Gene_Hobbs Resident bibliophile Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Sep 2006 Location: Durham, NC, USA Posts: 133	Re: Reduced Oxygen Breathing System for Training Chuck (designed and did first research) just started at Duke but already has a great plan for the next version of this system. It was designed and built at the Naval Aviation Medical Research Lab in Pensacola FL. The first version was built for them by the chamber at Duke over ten years ago. Great system, currently works off mass flow controllers. __________________ http://rubicon-foundation.org/ Home of the Rubicon Research Repository. For help getting started with the Repository, please visit our FAQ page. PLEASE support our work. "Oxygen is addictive and deadly. Everyone who uses it will eventually die" --RW Hamilton, PhD 1991 Last edited by Gene_Hobbs : 21st February 2008 at 04:34. Reason: cool system but uses a ton of gas, hence the re-design
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21st February 2008, 04:53	#7 (permalink)
RonMicjan Cap Ron scourge of the NW Current Rebreather/s: Megalodon Dolphin Home Build Other Rebreather/s: Sport Kiss Classic Kiss Dolphin Home Build Join Date: Feb 2005 Location: Cape Disapointment, The Graveyard of the Pacific Posts: 1,120	Re: Reduced Oxygen Breathing System for Training cool setup, I know a few guys I would like to use that on... Hmmm, got me thinking about blending up some OC mixes to put students on and have them do math problems and logic type tests. Then of course there is that secret video of someone (who shall remain nameless) going hypoxic (during a controlled, monitored by a physician, test)on a CCR with the O2 turned off... If I recall, the lights went out at 8% O2 and 65% perfusion on the pulse oximeter. Now what kind of Moron would volunteer for a test like that? __________________ Marine rescue, towing and salvage. Interfering with natural selection since 1983. www.tmishop.com Diving bits etc. www.seatowpdx.com The Summer Job
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21st March 2008, 17:07	#8 (permalink)
Eliot Danner RBW Member Current Rebreather/s: Classic Kiss Optima rEvo Other CCR Dolphin Other Rebreather/s: Sport Kiss Optima rEvo Other CCR Dolphin Join Date: Jul 2006 Location: Virginia Posts: 227	Re: Reduced Oxygen Breathing System for Training Dave - you have all of the coolest toys... __________________ Eliot Danner CCR Instructor This post may be up to 80% accurate...the remaining 20% is speculation.
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21st March 2008, 19:04	#9 (permalink)
Sutty Classic Kiss diver Current Rebreather/s: Classic Kiss Other Rebreather/s: Join Date: Jun 2005 Location: Glossop, Derbyshire, UK Posts: 835	Re: Reduced Oxygen Breathing System for Training I did an explosive decompression from 8000' to 25000' in about 3 seconds in a hypobaric chamber a few years ago, then took off masks to breathe chamber air and was pretty hypoxic after 2-3 mins, couldn't write properly, pulse oximetry 56%, but still with it enough to put my mask back on when told to. I've also breathed from my rebreather with O2 off, sitting at home (with a briefed resuscitation officer/ex-intensive care nurse sitting next to me!). Didn't have pulse oximetry that time but got rather blue and was pretty dizzy by the time my kiss displays read 0.05! - still good enough to appreciate the blueness and to take mouthpiece out though. Interestingly my symptoms were not particularly consistent in the two instances, and I have heard anecdotally that hypoxia symptoms can vary from episode to episode which may reduce the value of the exercise. If you are going to do anything like this please do so with appropriate trained and briefed support/supervision. __________________ Never forget that life is a finite resource.
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21st March 2008, 21:13	#10 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Evolution Megalodon rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,907	Re: Reduced Oxygen Breathing System for Training Quote: (Originally Posted by Sutty) Interestingly my symptoms were not particularly consistent in the two instances, and I have heard anecdotally that hypoxia symptoms can vary from episode to episode which may reduce the value of the exercise. Hi Sutty, good post. RAF Chamber? What the med guys at the military chamber here teach us is that you never loose a symptom from episode to episode, but may add new ones. If you had a visual disturbance the first time you ought to keep that symptom for life, but might notice new ones in addition to the first one later. Interestingly enough, my first symptom is the sensation of heat, or bright sunlight, on the back of my head. This and a glare sensation of bright light, which is actually the loss of vision due to retinal hypoxia being perceived as a loss of vision due to bright light. The knowlage learned in the chamber saved my ass once, as you will read here if interested (the hypoxia part is about halfway thru): Untitled In the USA, chamber rides are free for licensed pilots. The FAA runs the program and the USAF does the rides. All you need to do to become a licensed pilot is to go to an aviation medical examiner and obtain a 3rd class medical and student pilot license. You are instantly a licenced pilot and can then go to the chamber. It's one of the last "Good Deals" available. Dave . __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com Last edited by Dave Sutton : 21st March 2008 at 21:24.
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