CPAP machine with built-in filtration

[lindalq]

Hi everyone,

Just want to get some of your opinion on this. Our fourth year biomedical engineering design project at University of Toronto involves improving on CPAP machines and this is one of the idea we brainstormed. We would definitely love some user feedback on this.

What do you think of a CPAP machine with built-in filtration system? This way, you don't have to especially buy/prepare distilled water for it. Instead just pour tap water into it and the machine will make sure the humidified air that goes into your hose is purified and filtered.

Please let us know some of your opinion, such as:
a) Is using distilled water inconvenient for you? If so, please describe.
b) How do you regularly obtain distilled water? And how to you obtain it when you're away from home?
c) Would you be interested in this feature?
d) How much more are you willing to pay for a machine with built-in distillation function? (this is used to rank the worthiness of this idea in comparison with our other ideas).

Oh, and from reading some comments on the forum, it seems like cleaning the reservoir is also another inconvenience. What do you think of changing the design of the reservoir so that it's easy to clean? Is the current reservoir design actually hard to clean? and how much more are you willing to pay for a machine with this feature?

Thank you!! Much appreciated!!

(Any feedback would be awesome since we've been getting mixed feedback regarding this and we would really like to key down a design which will improve CPAP therapy. )

[BlackSpinner]

You need to do more research.

[lindalq]

You need to do more research.

Hi, could you please expand on this? We looked into different CPAP machines and it seems like they all require distilled water?? Maybe we're missing something, and we would definitely love your inputs on this.

[LSAT]

The newer CPAPs (Resmed S9) has a dishwasher safe humidifier reservoir...easy to clean.....also, with distilled water, the reservoir does not need to be cleaned very often.

Distilled water is easy to get and it is cheap.....Usually under $1 gallon in supermarkets and drug stores.....very convenient.

I personally would not pay any extra for any of these features.

I agree with Black Spinner.....you need to research CPAP machines and look at their features.

[BlackSpinner]

The only reason to use distilled water is to prevent mineral build up in the humidifier tank and even that is solved by using vinegar once a week.

and the machine will make sure the water that goes into your hose is

Water doesn't go into the hose.

[lindalq]

Distilled water is easy to get and it is cheap.....Usually under $1 gallon in supermarkets and drug stores.....very convenient.

I personally would not pay any extra for any of these features.

Hi, thank you so much for your input.
I guess what we meant by inconvenient is that you have another item to buy for your CPAP machine, and wouldn't it be easier to have a machine that allow you to directly fill with tap water? Also, the way we imagined that distilled water poses inconvenience is that when you are travelling or away from home (ie camping), you might not have convenient access to distilled water. Would we be wrong to assume this? Also, what happens if you ran out of distilled water at home without realizing it?

Although you mentioned that you would not pay any extra for these features, if two machine cost the same and one have this feature and another doesn't, which one would you choose? Also, what if the filtration only cost less than $5? Would you still not pay for this extra feature? We've been looking into different filters and these cost minimal, and easy to be integrated into the system we're targeting.

thank you for your reply, we really do appreciate your feedbacks.

[lindalq]

The only reason to use distilled water is to prevent mineral build up in the humidifier tank and even that is solved by using vinegar once a week.

We understand that one reason the distilled water is to prevent mineral build up, but we thought the more important reason for distilled water was so the microbes in the water will not get into your lungs? Our researched lead us to this, which made us believe that the main reason for using distilled water is to prevent infection of the person? ‘the use of tap water (for sleep apnea machine humidifier) within Neti pots in Louisiana has led to a few reports of harmful parasite infections affecting the brain’ http://sleepdisorders.about.com/od/livi ... difier.htm

Furthermore, isn't another reason to not use tap water is because it contain minerals that you definitely don't want to breath into your lungs?

Thank you for your feedback. please let us know what you think.

(Also, regarding your comment about water getting into the hose. I think we meant about the humidified air. sorry for the misunderstanding)

[Goofproof]

I'd be willing to pay nothing extra, as per above answers. That not a useful upgrade. A large HEPA filter on the intake that will last over 6 mo, and will cost less than 5 dollars to replace, might be useful, but the cost would be under 5 dollars a unit to add. Not much chance of ripping off customers with that.

Adding a FOOLPROOF valve to keep water out of the blower, short of dropping the whole Xpap in the tub, would help the clumsy, again the cost would be small to add it to the tank. HINT ( O-RING, marble sized ping pong type ball, very light stainless steel spring to seat it, working pressure will open it to flow. It will also prevent O2 backflow if used, cost under 5 dollars.

Since applying these fixes don't allow much $$$ to rip off the users, they aren't going to happen. You are looking for big bucks for little help, we don't want or need that Jim

[Julie]

I guess I'm different from most of you - distilled water costs a bit more up here, comes in big jugs that are heavy to carry home for me and then have to be put someplace low down out of sight so I have to drag them back up and out to use them... I'd be at least interested to know what you might come up with.

I do find the humidifier a nuisance to clean (and put back together properly), even if I do it pretty rarely, so while Resmed ones might be good now, mine still isn't!

I'd like to see some kind of feet on the machine that'll stay where you put them - i.e. if I want to move the machine I'd need 2 hands I guess, but at least I wouldn't be afraid of it sliding off the edge of the shelf.

And some kind of a fail safe valve that won't let water back into the machine if you do end up tipping things somehow, then having to use rice or just 2 'down' days to dry out the machine and hope it hasn't been permanently damaged.

[Todzo]

I believe that a humidifier was added to CPAP machines to help relieve some of the symptoms which result from the ventilatory instability which the pressure of CPAP tends to induce.

Rather than make the “symptom soother” better why not go for dealing with the ventilatory instability which CPAP tends to induce. Solve that one and they will beat a path to your door!!!

Note: to solve this one will require an interdisciplinary approach!!!

[hobbs]

"Our researched lead us to this, which made us believe that the main reason for using distilled water is to prevent infection of the person?"

College? Really?

[Goofproof]

"Our researched lead us to this, which made us believe that the main reason for using distilled water is to prevent infection of the person?"

College? Really?

Correct, "Those that can do, Those that can't teach, facts that they were taught by those that can't or wouldn't"

[SleepDisturbed]

As a no or low cost option, sure, why not? Seems like a hard slog though, home distillers seem to be bulky, expensive items. Don't know how you can squeeze something like that into the typical cpap/apap footprint.

Grabbing a jug of distilled water at the grocery every week is pretty easy.

[Rustsmith]

My wife and I both use our local tap water. The source is currently deep wells and it is treated, so bacteria is a minimal issue and parasites are highly unlikely. Our water is soft, so scale growth is not rapid. To prevent it we dump the water every few days, just like an open cooling system goes through blowdown. To remove any scale that does build up, our humidifier tank opens up very easily and we soak the bottom heat transfer plate with vinegar for a few minutes. We've been doing this for years and have not had a scale buildup problem.

With that said, there have been reports in recent threads here from others living in areas with hard water where even coffee makers have limited lifetimes.

If you end up accepting this project, you should give some serious consideration to of an ion exchange tube. The only question would be whether you exchange for H+/OH- for deion water or for Na+/Cl- for softening. If you decide the softening route, remember that the heat transfer plates are generally stainless steel that can be susceptible to increased pitting in oxygenated chloride solutions.

[-tim]

Many of us already use tap water. The problem with distilling water is you have a heat or steam source near a bed which could be on par with smoking in bed as far as safety is concerned. If CPAP machines use too much power, then battery backup is a problem. Distilled or demineralised water is very cheap in most parts of the world compared to the local energy requirements to make it locally.