Dry Hypoxia Training for Rebreather Divers
- Thread starter Dave Sutton
- Start date
matt
Well-Known Member
Yes Clare - good discussion going on - even if a bit cyclic some good info is coming out. As always, many opinions. It's good to have Paul chipping in too!
Matt.
anarchista
New Member
silentbob
Member
And that my friend sums it up perfectly.
Dave Sutton
Banned
Technical questions gladly answered. Meta-discussions on the discussion and discussions of philisophy are not able to be reduced to measurable metrics, so... there's no answer.
I think that the discussion has reached it's "normal internet conclusion" when no more technical information is really being offered, and it's devolved into "feelings" about things. I don't deal with feelings, just hardware and it's application to science, so I've little more to offer. All I could offer is a technical description of how a ROBS system works, so here goes that.
ROBS systems work like a rebreather, with 3 02 sensors measuring a loop, with a setpoint controller and a solenoid. Only difference is that the setpoints are adjustabl BELOW 0.21 PP02 and that the solenoid controls an input of NITROGEN into the loop to dilute it below 0.21. The "solenoid" is actually two solenoids in series, both opening and closing on command, so that a leaking solenoid cannot allow pure nitrogen into the loop. PP02 is constantly monitored by the trainer. It's sort of a rebreather system turned inside out.
A few other facts that are not subject to the way we "feel" about things: This training has been conducted for decades. It is being conducted today. It is available in two flavors (hypobaric chamber and ROBS). The injury rate is nil. The experience of slow hypoxia exposure is the same physiologically no matter if the field environment is hyperbaric (diving) or hypobaric (aviation). I am not aware of any student who went thru the training that did not debrief the sesson as having been a positive experience, or one that did not have training value to them. None of the current participants in the discussion objecting to the training have ever taken it, thus they have no framework for discussion. None of the participants in the discussion here who HAVE taken it are writing to say that it was a negative experience. Those are all simple facts. If others want to move into areas of speculation as to what possible negative consequences might arise... feel free, but that's far outside of my area of interest.
So, a poll question: Is there anyone here who has taken the training (either formally or informally) and found that the knowlage gained has REDUCED you situational awareness or DECREASED your overall level of safety?
Thought not.
The rest is just a meta-discussion that has no interest to me other than as a study in how people rationalize not doing something that is discomforting to them. It's OK... nobody is twisting your arm.
Off to actually go forth into the world now, riding a ferry across a very angry Lake Michigan to lecture at the Shipwrecks and Technology symposium. Anyone local to the area is invited to join us.
shipwrecksandtechnolgy.org | Shipwrecks & Technology 2012
Back on Monday, then packing, then setting forth aboard EXPLORER to make a 2 month run from Rhode Island to Florida and points south. Expecting less internet and more sunshine.
Best,
Dave
.
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liztribe
New Member
Opening line of the first post on this thread:
Opening line of the "closing" post:
It would appear the intent of this thread has changed since its original post. At first we're talking about the ethics of students partaking in this exercise on a living room couch and now we're asking for technical information? Ethics are not a science. Teaching is not a science, it's a philosophy and that teaching philosophy will vary from instructor to instructor and student to student, no two students are the same. Students are not hardware or machinery. Students have feelings. To be an effective teacher, an instructor need to read a student's feelings, and ensure that the teaching material is being adsorbed. Teaching is not data entry. You teach a student, you program a machine.
So based on the foregoing change in focus, would you agree that it is unsafe and unethical for students to partake in this hypoxia exercise on a living room couch; however, would be an interesting exercise for a diver on his/her own time to partake in, should he/she have access to a facility which conducts the exercise with the preambled understanding that doing this once only provides incomplete data and, further, that it is unknown how the data will be effected by other elements present in a diving environment which are not present in a dry environment (i.e. narcosis).
Anyhow, it would appear that class has been dismissed. It's been an interesting discussion. Happy diving everyone.
Opening line of the "closing" post:
It would appear the intent of this thread has changed since its original post. At first we're talking about the ethics of students partaking in this exercise on a living room couch and now we're asking for technical information? Ethics are not a science. Teaching is not a science, it's a philosophy and that teaching philosophy will vary from instructor to instructor and student to student, no two students are the same. Students are not hardware or machinery. Students have feelings. To be an effective teacher, an instructor need to read a student's feelings, and ensure that the teaching material is being adsorbed. Teaching is not data entry. You teach a student, you program a machine.
So based on the foregoing change in focus, would you agree that it is unsafe and unethical for students to partake in this hypoxia exercise on a living room couch; however, would be an interesting exercise for a diver on his/her own time to partake in, should he/she have access to a facility which conducts the exercise with the preambled understanding that doing this once only provides incomplete data and, further, that it is unknown how the data will be effected by other elements present in a diving environment which are not present in a dry environment (i.e. narcosis).
Anyhow, it would appear that class has been dismissed. It's been an interesting discussion. Happy diving everyone.
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anarchista
New Member
You can show any scientific material. Which That confirms there is no impact of high ppN2?
Reading this, there is no difference Whether we go for pure inert gas, or consume oxygen metabolism in hard work the anaerobic energy yields, it is just hypoxia.
Dave doing pure marketing.
greet rc
silentbob
Member
Well you can object that it's devolved only into a discussion about feelings, that would be one way to ignore the question. The question that needs answering is one that underlies the whole discussion, it is not about feelings it is about empirical evidence (information acquired by observation or experiment), Science.
What evidence is there that a diver can reliably detect and interrupt the hypoxic event or to put it another way. How do you know that the early symptoms of hypoxia will not be often masked by other physiological phenomena?
Coming public with a hypothesis prior to evaluating it's merit is not worthwhile. Your hypothesis is, as far as I can tell, that there is merit in divers undergoing hypoxic awareness training in the same manner as the aviation industry does.
Please keep your responses limited to the relevant field of diving.
Dave there is no need to get so defensive this is just one form of review that all ideas go through.
Hopefully you can answer my question when you get back.
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silentbob
Member
How can an experience be anything other than subjective? How can what we "feel" not be what we experience?
And your claim that
That is a bare assertion, not a fact, it needs citation.
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anarchista
New Member
Dave mistakenly assume again, that we do not have basic knowledge.
We have an elementary knowledge, of the topics about which we speak.
Maybe a little more.
I was at the lecture, moving more relevant for diving aspects.
SA Gulyar is a professor medicine doctor who participated in most experiments diving medicine in the Warsaw Pact.
It discovered the phenomenon that allows lungs increase gas exchange, for very dense respiratory factors.
Here's information about hypoxia in divers, which is not present in the pilot.
So I know that you do not have the knowledge, you want to do business training.
Not knowing the issues hypoxia in diving.
http://www.ptmith.net.pl/materialy/konf/konf7streszcz.pdf
S.A. Gulyar
Institute of Physiology them. A.A. Bohomoltz in Kiev
Ukrainian Academy of Sciences
POSSIBILITIES TO ACCELERATE REHABILITATION OF MAN
AFTER DEEP DIVES WITH THE HELP OF BIOPTRON
TECHNOLOGIES
Rapid compression and load by density provoked transient
venous hypoxia even in conditions of relative rest and moderate
hyperoxia (N2+O2: 180-220 mm Hg). It is based on non-correlation
between increasing rate of O2 coming into alveoli and arterial blood and
slowering of rate of O2 transport to tissues.
.... .
greet rc
anarchista
New Member
The construction of diving equipment is the direction called "pure gases."
It is known that this technique has disadvantages for those who are familiar with the procedures of the method of monkeys (without understanding).
The first was the SMS Draeger, the project was closed.
http://www.therebreathersite.nl/SemiClosed Rebreathers/Images/Germany/SMIII/Picture2.jpg
Successful design is the Canadian laminar resistance.
http://rebreathers.pl/forum/download.php?id=81
There are further steps, that remove defects earlier solutions.
It is for these reasons, so I was very interested in the early symptoms of hypoxia for binary mixtures. Then there is the pure inert gas as a threat.
The question was above the level of understanding and recognition of research, there is no answer.
What is the most effective assessment of the usefulness of the training.
greet rc
It is known that this technique has disadvantages for those who are familiar with the procedures of the method of monkeys (without understanding).
The first was the SMS Draeger, the project was closed.
http://www.therebreathersite.nl/SemiClosed Rebreathers/Images/Germany/SMIII/Picture2.jpg
Successful design is the Canadian laminar resistance.
http://rebreathers.pl/forum/download.php?id=81
There are further steps, that remove defects earlier solutions.
It is for these reasons, so I was very interested in the early symptoms of hypoxia for binary mixtures. Then there is the pure inert gas as a threat.
The question was above the level of understanding and recognition of research, there is no answer.
What is the most effective assessment of the usefulness of the training.
greet rc
Johan Isaksson
Member
Personally I think the discussion turned quite nasty with a lot of aggressiveness and in my opinion Dave wasn't the chief party to blame there. I don't know either of the parties involved so consider me reasonable unbiased.
He presented something that is well documented in another industry and would be theoretically applicable in our setting. A lot of the responses were very negative and some outright hostile, mostly for the wrong reasons as well.
The only real argument against is that it's only proven useful in the aviation setting and that our hyperbaric setting with additional narcosis might complicate things. That is a pretty big if but it's still a topic worthy of discussion.
He presented something that is well documented in another industry and would be theoretically applicable in our setting. A lot of the responses were very negative and some outright hostile, mostly for the wrong reasons as well.
The only real argument against is that it's only proven useful in the aviation setting and that our hyperbaric setting with additional narcosis might complicate things. That is a pretty big if but it's still a topic worthy of discussion.
Dave Sutton
Banned
First of all, Bob, we are friendly and use first names here. I have one, so use it. This is a gentle warning to play nice here.
Second, the training for divers is already fait-accompli, having been done for decades in diving circles. I did it as part of my mixed gas training in 1978. I was just bringing attention to what many did not know was/is already occuring. It's been part of "underground technical diver training" since LONG before there was such a thing as technical diving certification agencies. I can think of several hundred divers who have already done the training.
Third, I gave the technical information, and then got bored when it turned away from any serious discussion and became simple name calling. I have no time or interest in convincing people who believe one thing to believe another. Thoughtful people consider information and make up their own minds. Closed minds are nothing I can do anything about.
I can't make heads or tails of what anarchista means when he writes, so I simply cannot address it either positively or negatively.
Best,
Dave
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silentbob
Member
Threats aren't a classy way to behave Dave. I certainly didn't mean an unfriendly gesture by using your last name. It seemed less ambiguous what with us being on page 18 and a dozen Daves on the forum. (though not sure any have contributed)
And you have no evidence (or at least have presented no evidence) it is of any value. You are making an "argument from antiquity" saying because it was a part of your training in 78 therefore it should be a part of training now.
What technical information did you give that supports the efficacy of what you were proposing? And what name calling? I can't see any at all. Not serious discussion? Just because it moved to being about the "wetware" between our ears?
You will have to excuse me for pointing this out Dave. It is very hypocritical to in one paragraph complain of name calling then in the next accuse all who disagree with you as "closed minded" and "Un-thoughful". What gives?
I am asking you for what it is that you base your advocacy on and you respond by getting defensive. That is what derails threads. It's a pity because the idea has potential but without evidence that it's a risk mitigation how do you know that you are not falsely arming divers? A simple admission that you don't know would suffice. Ignorance is not a crime, if it was I would not be a free man.
I suspect he is using babelfish or similar. I have tried translating it back into Polish then to Japanese and back to Polish then English but I'm afraid it doesn't help...
silentbob
Member
Look I don't understand the complaint of nastiness or aggressiveness? I can't see holding someones feet to the fire (you'll have to excuse the nasty metaphor
) over having a question directly answered as being nasty. I would expect that if I claimed that it's a good idea to <insert idea here> then I would be asked to provide evidence to support it.I wouldn't like to be a member of a forum where every idea got a free pass to verity.
Johan Isaksson
Member
There was actually a lot of evidence provided in the beginning of the thread. The method is proven and obviously useful in hypoxia management in aviation. It is also safe with extremely few adverse events reported. I only did a quick browse but there are plenty of studies available.
Our question, as rebreather divers, should be if this is still useful to us when narcosis and excertion comes into play. This thread has had precious little of that.
Our question, as rebreather divers, should be if this is still useful to us when narcosis and excertion comes into play. This thread has had precious little of that.
anarchista
New Member
I suspect he is using babelfish or similar. I have tried translating it back into Polish then to Japanese and back to Polish then English but I'm afraid it doesn't help...
Lecture Professor Gulyar was Russian. This text is still for me to understand.
It is possible that information gap.
"Rapid compression and load by density provoked transient
venous hypoxia even in conditions of relative rest and moderate
hyperoxia (N2+O2: 180-220 mm Hg). It is based on non-correlation
between increasing rate of O2 coming into alveoli and arterial blood and
slowering of rate of O2 transport to tissues. "
Dave playing pure marketing, do not answer the questions.
Evaluates speakers.
Dave can easily find the section in which you do not understand the text, because you do not know this area: SCR CMR, CVR, SCR constant ppO2.
Who was running and running away from an answer.
I presented my objections, breathing pure nitrogen.
It was nice, because so much fear of such an accident.
On the other hand, just developing a class structures Self Mixing System "pure gases."
greet rc
erikradstrom
Deep Pursuit 001
I have some trouble understanding the things you write, but do I understand you correct when you compare the things Dave suggested in the beginning of this thread with breathing pure nitrogen?
If Im understanding that correct you two are speaking about two totally different things.
I hope this is just a bad translation, because this is just rude!