matt
Well-Known Member
Not convinced, yet. Is there any actual evidence that the basic method works in a practical sense? The problem of calculating tidal-volume is still wide open as far as I can see.
Matt.
CO2 Monitor (End-tidal) - good news
- Thread starter gianaameri
- Start date
Not convinced, yet. Is there any actual evidence that the basic method works in a practical sense? The problem of calculating tidal-volume is still wide open as far as I can see.
Matt.
Dave Sutton
Banned
I can't even comment on the CO2 part: What are We talking about? Why worry about how it's calculated when you can't even measure the gas reliably?
Cart before horse.
My comment was more global, meaning not specific to the CO2 system. That was a small fraction of the technology demonstrated. It was actually the only technology that wasn't ready for prime time.
On other technologies like the audible broadcast into the DSV, use of RF signal broadcast from pods to BOV using the airspace inside the breathing hoses, etc... Things largely overlooked by most: why not?
Really: I'm done talking about it. Like a few other subjects there are very few people who can discuss the technology without being distracted by the politics. All I'll finish with is an observation thst anyone wanting to build a state of the art system would be foolish not to study the system to take the good while leaving the bad.
Dave
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Cart before horse.
My comment was more global, meaning not specific to the CO2 system. That was a small fraction of the technology demonstrated. It was actually the only technology that wasn't ready for prime time.
On other technologies like the audible broadcast into the DSV, use of RF signal broadcast from pods to BOV using the airspace inside the breathing hoses, etc... Things largely overlooked by most: why not?
Really: I'm done talking about it. Like a few other subjects there are very few people who can discuss the technology without being distracted by the politics. All I'll finish with is an observation thst anyone wanting to build a state of the art system would be foolish not to study the system to take the good while leaving the bad.
Dave
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matt
Well-Known Member
Why are you taking the stand point that CO2 cannot be measured accurately?
Sensing does not seem to be the issue - sensing exists, it is the end-tidal calculation that is not existing or working outside the PDF. For clarity I'm talking about the APOC method, not the skin method.
Perhaps someone can find the PDF, I can't seem to find it...maybe it got pulled.
Matt.
Dave Sutton
Banned
Excellent news! Let's get on with it then.
Send me a link to the supplier where I can buy today a fully tested and highly reliable C02 sensor that will work in a 100% humidity hyperbaric environment with a high helium fraction and I'll have it installed in my rig this summer.
The monitor I build may not indicate end tidal C02 (that's not my initial goal), it just needs to be a reliable indication of C02 in the loop. Ought to be a piece of cake for someone like me who has built PP02 monitoring systems for the last decade, right?
I'll order a sensor within minutes of being told where to purchase it.
Problem solved!
Of course if I *can't* buy a sensor today, then I can't build a simple monitor next month, and if I can't build a simple monitor next month then I certaintly can't get to the end goal of a real end tidal C02 monitoring system next year.
Thanks,
Dave
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matt
Well-Known Member
Are you saying that the sensor used in the APOC does not give decent readings for CO2? What about the one in the Sentinel? That's not my understanding.
I think you're just trying to start a Friday argument...
Matt.
Dave Sutton
Banned
What's an apoc? :abducted:
I'm not building an apoc and have not had any contact with them in, oh... over two years. That's old news from the Plestiocene Epoch. Who in the world cares? I've played with over 50 different rigs, that's just one of the pack. Anyone still worrying about it is probably also worrying about when their Oceanic Phibian or their CCR-2000 is going to arrive. It's long past the time to move on to other more productive subjects.
I'm not trying to argue anything... just curious where I can buy a C02 sensor this afternoon so I can make a display this weekend. Ought to be easy, right? Off the shelf stuff. I was building things I could not buy ten years ago and I feel the urge to do the same again.
Best,
Dave
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I'm not building an apoc and have not had any contact with them in, oh... over two years. That's old news from the Plestiocene Epoch. Who in the world cares? I've played with over 50 different rigs, that's just one of the pack. Anyone still worrying about it is probably also worrying about when their Oceanic Phibian or their CCR-2000 is going to arrive. It's long past the time to move on to other more productive subjects.
I'm not trying to argue anything... just curious where I can buy a C02 sensor this afternoon so I can make a display this weekend. Ought to be easy, right? Off the shelf stuff. I was building things I could not buy ten years ago and I feel the urge to do the same again.
Best,
Dave
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GLOC
real name: Gareth Lock!
Guys,
Looking from the outside in, chill.
Maybe the fact that words are being typed and not spoken, and people like to type 'shorthand', so words get taken out of the context to which they were written.
'Sensing' technology exists in a tightly controlled temperate normobaric environment using 'land based' equipment that can be used to measure the CO2 in a patient in a relatively non-dynamic environment. This technology can measure end-tidal CO2 (as has been proved) to the required resolution and accuracy for the systems in which it is installed (ORs). This can be bought off the shelf.
Does this same system work in a humid hyperbaric trimix submersed environment capable of being supported by a single diver? No. It needs investment which will ultimately end up as NRE on your product.
Regards
Looking from the outside in, chill.
Maybe the fact that words are being typed and not spoken, and people like to type 'shorthand', so words get taken out of the context to which they were written.
'Sensing' technology exists in a tightly controlled temperate normobaric environment using 'land based' equipment that can be used to measure the CO2 in a patient in a relatively non-dynamic environment. This technology can measure end-tidal CO2 (as has been proved) to the required resolution and accuracy for the systems in which it is installed (ORs). This can be bought off the shelf.
Does this same system work in a humid hyperbaric trimix submersed environment capable of being supported by a single diver? No. It needs investment which will ultimately end up as NRE on your product.
Regards
iain/hsm
Member
Hey Dave.
Long time. Just adding to my 15,
You want that fully tested, reliable 100% humidity PPc02 yada yada C02 Monitor with STANAG A or STANAG B approvals, can do either.
Oh and regarding the Phibian you really want to go that far back too?
Iain Middlebrook
Dave Sutton
Banned
Hey Mate, good to see you: I knew you were lurking here! Glad we teased you out.
Phibian Hell... I want to go back to the UT-240. The new-blood divers who think that the Apoc was he first highly touted rig with huge money behind it to crater have just not been around long enough. The Phibian almost ended Oceanic. How many millions were wasted? What other rigs went bust? I can count them by the half dozen. Nothing new under the sun.
So, tell us what you can offer for a C02 monitor that I can plug into my Meg.
Dave
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Phibian Hell... I want to go back to the UT-240. The new-blood divers who think that the Apoc was he first highly touted rig with huge money behind it to crater have just not been around long enough. The Phibian almost ended Oceanic. How many millions were wasted? What other rigs went bust? I can count them by the half dozen. Nothing new under the sun.
So, tell us what you can offer for a C02 monitor that I can plug into my Meg.
Dave
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iain/hsm
Member
Hey just racking up my 15 here Dave, before I can stir the mud.
Here's six from memory to do from our side of the pond.
The KrakenC2
The Normalair Deep Dive 500 (better known as James Bond in Yellow)
The Krasberg Push Pull (Cos us lot did all the work on it )
The Helinaut
The Lama
The Comex HydraV
All this while you lot were still mucking about with that ArawakV
with it's (wait for it) "Pump Pod" LOL
Iain Middlebrook
Dave Sutton
Banned
All this while you lot were still mucking about with that ArawakV with it's (wait for it) "Pump Pod" LOL
OOhh.... that hurts.... :flame:
I did some of the manned tests on that thing.. It was called the Divex Push-Pull by the time I dove it. Ergometer bike rides at 1030 FSW. Nothing like The Vigor of Youth.
Dave
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Dave Sutton
Banned
Based on the sensor used... Uhh...
I'm taking a cautious wait and see on how that one turns out.
All I want is a sensor. I'll handle the rest for the test.
Dave
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iain/hsm
Member
Ahaha I thought that might get your attention.
The "Divex" we talk about was of course the original Divex Louisiana Dave Kenny's lot.
Not that "little" workshop in Aberdeen with the same name, they hadn't existed back then.
I was with the other mob, Sub Sea International in 79 we had the "Krasberg system" oh they were the day's.
All rust, leaks and squeaks. LOL Iain Middlebrook
Dave Sutton
Banned
Yup. He was a friend, bought my Superlite from him in about 1980. Black with polished brass and gold flake gelcoat. Talk about 1980's chic.. Long hair, a gold Rolex, and a Black Superlite with metal flake. Man... what style we pretended to ... :help: Disco-Divers.
DIVEX provided our rebreathers, which were DIVEX 3000 semi closed circuit, umbilical fed rigs mounted to the DIVEX Gas-hat, which was a derivitive of the "Swindell" Helmet which became the "Beckman Advanced" helmet and rebreather system and finally was a DIVEX product.
His book "The Business of Diving" was/is a classic. Has an excellent description of the Sealab III accident, where if you remember the diver who died did so after locking out with a Mark-XI rebreather that had not had the scrubber packed. Hypercapnic at 450 after a minute, dead a minute later.
Last time I saw him was in about 1988.. I bought used 24 pairs of the AGA Double Sets that had been used for sat bailout from him for a project. Lost track of him after that.
Long ago in a distant world: Morgan City Louisiana, 1979, Where the bars were so tough that they checked you at the door for a gun, and if you didn't have one they would give you one. From dive school to the real world in the flash of an eye. Seems a lifetime ago. I saw my first man die the day after I got offshore for the first time: A rigger who was crushed to death when he got between the stock of a 5 ton barge anchor and the rail of the barge. They were beginning to pick it up with a crane, the barge rolled, the stock flippped from one side to the other and crushed him against the rail (4" pipe rail). "What do we do?"... "Uhh.... get the fire hose". That was the day I stopped thinking that commercial diving had any glamour. Didn't take very long. Santa Fe Engineering, the Lay barge CHICKASAW. I can still smell her.
<sigh> We should start a "Sea Story" forum here for tales of ancient times.
Back to our regularly scheduled program now. How about a STANAG Spec C02 sensing system for little old me?
Dave
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DIVEX provided our rebreathers, which were DIVEX 3000 semi closed circuit, umbilical fed rigs mounted to the DIVEX Gas-hat, which was a derivitive of the "Swindell" Helmet which became the "Beckman Advanced" helmet and rebreather system and finally was a DIVEX product.
His book "The Business of Diving" was/is a classic. Has an excellent description of the Sealab III accident, where if you remember the diver who died did so after locking out with a Mark-XI rebreather that had not had the scrubber packed. Hypercapnic at 450 after a minute, dead a minute later.
Last time I saw him was in about 1988.. I bought used 24 pairs of the AGA Double Sets that had been used for sat bailout from him for a project. Lost track of him after that.
Long ago in a distant world: Morgan City Louisiana, 1979, Where the bars were so tough that they checked you at the door for a gun, and if you didn't have one they would give you one. From dive school to the real world in the flash of an eye. Seems a lifetime ago. I saw my first man die the day after I got offshore for the first time: A rigger who was crushed to death when he got between the stock of a 5 ton barge anchor and the rail of the barge. They were beginning to pick it up with a crane, the barge rolled, the stock flippped from one side to the other and crushed him against the rail (4" pipe rail). "What do we do?"... "Uhh.... get the fire hose". That was the day I stopped thinking that commercial diving had any glamour. Didn't take very long. Santa Fe Engineering, the Lay barge CHICKASAW. I can still smell her.
<sigh> We should start a "Sea Story" forum here for tales of ancient times.
Back to our regularly scheduled program now. How about a STANAG Spec C02 sensing system for little old me?
Dave
.
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matt
Well-Known Member
Cutting to the chase, I've no idea where you can buy just the part, that's not my point (not even closely related, actually). So sorry if that's been confusing for everyone, it's not my intention to wind anyone up here.
The point I was making is that there are commercial sensors available for measuring CO2 and they are used in rebreather loops, albeit not for end-tidal (which is what this thread is about). Unless someone who actually knows comes along and says they tested them and they didn't work then I think we can say they do make the measurement, here's what I found about the Sentinel sensor which is commercially available (so go ahead and research it if you like):
http://www.rebreatherpro.com/sentinel/ said:
There's more from VRT here about their sensor with some test results: http://www.technologyindepth.com/pdf/VR CO2 Sensing Module User Manual Rev A 1209.pdf
The problem is not the sensor (AFAIK) it is all the other gubbings needed to make it work. In the APOC case (which is relevant here as AFAIK this is the only project that really tried to solve this issue) this seems to be linked to the tidal-volume measurement (especially at low tidal-volume). That topic is debated to death elsewhere.
See Section 6: http://www.deeplife.co.uk/or_files/Fault_Study_CO2_Bypass_110105.pdf for an overview.
Perhaps one of the sensors Iain offers up will suit you better?
Matt.
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Dave Sutton
Banned
And this is where we probably differ, because in my estimation the sensor is the only real remaining technical issue. The one that Gian was playing with is the same as the one that Golem has, and is probably the same one that Gurr used, and the bottom line is that they don't work very well when they get saturated with water vapor. This was the self-same issue that the apoc presented. So, until that's "really" solved my guess is that we have a "bottleneck in the tech".
I'm hoping I am wrong though.
'Bout exhausted this.... time to pack for diving tomorrow.
Best,
Dave
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Dave Sutton
Banned