Design opportunities in Cave Diving?

[floridakid]

I heard that the Sentinel has an optional CO2 sensor but I don't know how it is set up. The ultimate would be a CO2 waveform (Waveform Capnography) displayed on the HUD, but that actually might be a little overkill. The advantage of the waveform is not only would you be able to asses how well the scrubber is removing CO2 from the breathing loop, but you could get real time feedback on the metabolic status of the diver. Unfortunately, with the way most rebreathers are set up, true end tidal (the very last of the gas from an exhalation) would not really be possible in the traditional sense. But a CO2 sensor located in between the counterlungs and the mouthpiece would at least ensure that the gas in the breathing loop is not hypercapnic.

I know the diver out there are more than likely aware of this fact, but I don't know how much you know about physiology...In a normal person, the urge to breath is not really stimulated by lack of oxygen but by a rise of CO2 levels in arterial blood. Essentially, if you breath gas that has a high level of CO2 (and a high level of CO2 is really not that much), the CO2 gradient (the level of CO2 in the blood versus the level in gas) in the lungs is changed and CO2 cannot as easily be eliminated. The body senses this rise in arterial CO2 levels and interprets it as a need to increase the respiratory rate. This can occur even with perfect arterial O2 levels. If the problem is not fixed fairly quickly, the person breathing the hypercapnic gas will at first increase their respiratory rate, then they will panic as they begin to feel the sensation of being out of breath. Eventually, as the CO2 level rises, the diver would panic, and the body would actually begin to produce even more CO2 and would further exacerbate the problem. Eventually, as CO2 levels rise in the blood, The very high CO2 actually causes sedation (not the good kind) and unconsciousness. The blood PH drops (because CO2 dissolved in blood is acidic) and the person dies.

[sskasser]

You are on!

It isnt one of these is it?

Nope, none of those. You'd be hard pressed to find one like mine at any shop.

[FW]

Nope, none of those. You'd be hard pressed to find one like mine at any shop.

OH, that one, with the pink line

[JerseyJersey]

Nope, none of those. You'd be hard pressed to find one like mine at any shop.

Then we need to dive!!

[sskasser]

OH, that one, with the pink line

Yep! That's the one! It was gorgeous without any line at all, but with the pink line....just WOW!!!

Then we need to dive!!

Indeed! Let's!

[DA Aquamaster]

You are on!

It isnt one of these is it?

It's not you (or at least all you), it's the reels....

[RubenN]

Thanks 'floridakid' that is very helpful for me.

Are you able to tell me a little about the specifics of a dive.
in terms of speleology:
-Do you take samples of the area/environment.
-do you take photos.
-how do you study the caves.
-what sort of additional equipment is used.

or if your not cave diving for research purposes, what is done when your in the cave?

much help

cheers

[floridakid]

I can't tell you much speleology, because I am just now getting into cave diving. In fact I don't even dive a rebreather. Most of my knowledge and experience relates to my profession as a paramedic that assists our medical director in writing medical protocols for a very rual EMS system with very long transport times. A few months ago, as a side project, I worked on a design for a safer Nitrous Oxide administration system for EMS that was not as prone to diversion (ems personnel huffing the gas between calls) and the design I came up with was pretty much a semi-closed rebreather. Unfortunately, it was not cost effective, too big, too complicated, and was pretty much an anesthesia machine (minus the volatile liquid anesthetics) mounted in an ambulance. It would have created more problems than it would have solved. Plus the average paramedic would need too much training to use the machine than what it was worth. But I learned a little about rebreathers in the process so it was not all a loss, lol.

[deepairmike]

Co2 monitoring already exists, and is not really that expensive. But it is not really needed. A properly maintained and packed unit should never be a problem. Your body will also tell you if you have a problem. Now if you could invent a solution for if that problem happened????

[deepairmike]

Let's see a photo of that reel?