Hello all!
I am currently upgrading a hyperbaric pod >>
I am looking indo equiping this with arduino to control and monitor the pressure.
I found a pressure sensor but I am wondering if there are valves that could be operated via the arduino board so that we may regulate the air flow inside the unit.
Thanks
Moderator edit: off-topic links removed.
The obvious questions here are;
Gas valves are used in the compressor industry, for cars (suspension stuff) and even in some diving gear. Maybe take a look at 2/2 DIRECT ACTING SOLENOID VALVES | Jaksa Solenoid Valves as a starter....
You're sucking air out of a sealed chamber - presumably with a person inside it.
To me this has "safety critical" written all over it and I'd be extremely cautious about modifying the chamber at all, but I'd be especially cautious about using a DIY hardware and firmware solution to control a safety-critical part of the chamber. What's the worst that could happen if your controller has a logic fault or hardware fault and does the wrong thing at the wrong time?
HYPERbaric = pressure++
HYPObaric = pressure--
either way your comments are valid!
OP your links are weird
check them out while not logged in as yourself 
Judging by the pod picture, the pressure increase is 2/10th's of a gnats fart anyway 
Maybe the original poster can give some more details?
Judging by the pod picture, the pressure increase is 2/10th's of a gnats fart anyway
Good point - all the hyperbaric chambers I've been in had inwards-opening doors.
Good point - all the hyperbaric chambers I've been in had inwards-opening doors.
One man chambers often open outwards, which does make you nervous.
Here is a pretty medical example with a "Intrinsically safe two-way communications system"
http://www.perrybaromedical.com/sigma-40-hyperbaric-chamber.html
I was in a one man chamber once, all steel, outward opening, its emergency communication system was a hammer.
If you had a problem you could attract attention!
The example above only takes you to about 2 bar above ambient but even so the door locking mechanism is quite susbtantial.
At only 2 bar the door hinges and lock have to contain 28lbs/inch2 of pressure on the door. Since it has a 40" dia door dia it has an area of 1256inches2 and so must contain 35,158lbs or 17 tons.
The original post looks very pretty but it cannot be containing much pressure.
Looks more like one of those sensory deprivation things.
The (banana) curved door could not possibly stand pressure.
radman:
I was in a one man chamber once, all steel, outward opening, its emergency communication system was a hammer.
If you had a problem you could attract attention!
Sounds like one of the drager coffin jobbies..... they give me the willies!
Theres a trend in sports for hypobaric chambers (for increased red blood cell generation), so I wonder if the widget above is related to that. They typically max out at ~6500M ASL.
Anyway, Im of the opinion sites like this are great when people offer advice on the design/coding. Often people plan to use arduino as a stepping stone/quick prototyping approach, rather than a final design.
Sounds like one of the drager coffin jobbies..... they give me the willies!
I don't know if was made by drager but its nickname was "the coffin".
It was one man and portable so they could pressurise you, sling you you in a truck and cart you off to hospital.
I was just in it for fun. It was very claustrophobic and the outward opening door did give me the willies.
To be injured and transported in it by road would have been hell.
Until now I have never really thought about the "coffin" name.
I took it to arise from the confined space, hopefuly nobody actually died in the one I was in.
From what I could investigate, the thing in the picture is not a hyperbaric chamber at all. It's an armchair with roof, a door and a TV. That's it.
http://www.mccormackdesign.co.uk/design/ovei-pod
It's an "Ovei pod," a phenomenally expensive "micro-environment," fitted with a fancy sound system, a video system, though that system would have to be small by today's standards, and dressed up with some comfy stuff, including its own air conditioner. It looks like the standard model runs about 100K USD. Some sites describe it as a little isolation room specifically for gamers. At that price, it would be less expensive to build a very nicely equipped 60 m2 media room.
Engadget says that it's "not for claustrophobic or poor people."
Here's a blurb: http://ifitshipitshere.wordpress.com/page/140/
I can't find any suggestion that the Ovei pod is able to support a pressure differential in either direction. The mention of gas valves suggests that the OP may be contemplating an oxygen-rich, rather than hyperbaric, environment.
Whatever is contemplated here, it should be done with care, and with a thorough understanding of all the issues and risks involved, or not done at all.
[Edit: Deleted redundant text.]
Hyperbaric is more lile pushing air into a sealed vessel. The traget pressure is 4.5 psi and I need to regulate the speed pressure increase. I found some accurate pressure sensors but I was looking to automate the speed of compression and decompression.
That's, what, 30 000 Pa of overpressure?
So, 1,3 atmosphere. If my calculation is correct, that's around 85 000 N of force on an opening with 60 cm diameter (something a person might crawl through). I would not mess around with those forces and the thing pictured in your first post most definitely could not withstand that pressure, even if you could seal the door itself.
Controlling the pump and a release valve is doable with arduino, but not advisable for this purpose in DIY method.
Okay, okay, I confess, somebody really knows who I am.
Once, when I was young, I went into an inflated building. It had no structural integrity, the internal air pressure was simply more than the external and that kept the whole structure upright.
For fire regulations all doors had to open outwards. Of course you do not have a single door in a pressured environment you have a double one.
Yes, yes it was me =( =( =( I opened both doors !!!!
This was not intentional I went through one door then the next.
I know, I know, the entire building started to collapse - it was stupidity of youth and entirely unintentional ( just like the problem with the train which we shall not go into here )
Anyway the overpressure could not have been too great and once the internal fans kicked in to try an stop several hundred people being suffocated a small army of people managed to force one small door closed against the remaining pressure which could have not been to large.
Radman, the pressure in that sort of inflatable buildings is usually around 250 Pa. That's far, far away from 30 000 Pa drfpoulin is mentioning.
The last such inflatable structure I was in was a tennis court (well there were 4 or 5 of them inside) and it had revolving doors so you didn't have to worry about releasing all that air.
The pressure differential could be felt once you enter, but certainly nothing uncomfortable. Sort of like what you feel when driving down a mountain road from higher to lower altitude.
@drfpoulin, please refrain from including off-topic links in your posts.
tmd3
I can't find any suggestion that the Ovei pod is able to support a pressure differential in either direction. The mention of gas valves suggests that the OP may be contemplating an oxygen-rich, rather than hyperbaric, environment.
Whatever is contemplated here, it should be done with care, and with a thorough understanding of all the issues and risks involved, or not done at all.
I echo tdm3.
If you are going to use oxygen then this requires special valves, oxygen is not something to be played with.
So some clarification please.
The flow of what gas are you aiming to control?
At what pressure are you aiming to do it.
There are probably you-tube videos that show experiments on what effect even a few % increase or decrease in oxygen content of the atmosphere can do.
Nature has settled on 21.5% in the atmosphere for a very special reason.
Tom.
I'm not sure how old you are but NASA blew three perfectly good astronauts up because of oxygen enriched environment.
drfpoulin:
Hyperbaric is more lile pushing air into a sealed vessel. The traget pressure is 4.5 psi and I need to regulate the speed pressure increase. I found some accurate pressure sensors but I was looking to automate the speed of compression and decompression.
is that 4.5psi OVER atmospheric, or absolute 4.5psi (eg ~1/3 ATM)?
Either way, I'd suggest you engage the services of a professional to help here, theres a lot more aspects to this than the relatively simple arduino+actuator bit (ie the answer to your original question was a yes)
Incidentally, is the plan just to do a 'me too' project on the CVAC?
Good luck anyway, as long as you're informed or engage informed consultants you at least know where you are.
There should not be any medical concerns regarding that overpressure. The increase in pressure is equivalent to diving three meters under the surface of water.
It's mechanical stuff that won't hold up.