CPAP Notes

Russell Bateman
August 2015
last update:

Continuous, positive air pressure.

Benefits of using a full-face mask
  1. Increased therapy adherence: The full face mask design allows for the delivery of therapy to both the nose and mouth, making it a good option for patients who breathe through their mouths while sleeping.
  2. Reduced risk of leaks: The seal on a full face mask is typically larger and more secure than that of a nasal mask, reducing the risk of leaks and increasing the effectiveness of therapy.
  3. Reduced dryness and irritation: The full face mask design can reduce dryness and irritation of the nose and mouth, as it delivers a continuous flow of humidified air.
  4. Increased comfort: Many full face masks have features such as a soft cushion, headgear, and adjustable straps that help to increase comfort and improve the fit of the mask.
  5. Improved sleep quality: With a full face mask with a good seal, patients can enjoy more restful sleep by reducing the number of apnea events and wake-ups.
  6. Suitable for all position sleepers: Unlike nasal mask, full face mask allows the patient to sleep in any position without worrying about mask displacement.

Cleaning any CPAP machine

Not all parts have to be washed as frequently as others. I only clean the hose and humidifier every few weeks whereas I clean the pillows that press against my face daily, i.e.: I never start a night on an unwashed pillow. (I collect the pillows, which will last for nearly ever if taken care of, and wash them once a week or so in order to have a clean "pile" of them for the coming week.)

  1. Disassemble and wet washable parts. This should include cleaning of
    • Pillows, daily
    • Face mask, weekly or daily when ill
    • Hose, every few weeks, more frequently when coughing
    • Humidifier, every few weeks or when detecting particulates in water

  2. Soap up hands with a couple of good squirts of dish soap, like Dawn®.

  3. Under flowing kitchen faucet, rub parts with soapy hands and set aside to rest with soap on them.

  4. Rinse hands, then thoroughly rinse each piece you've washed, setting the piece aside to drain on towel.
    • If pillow, either air-dry or hand-dry blotting with a paper towel or lint-free cloth.
    • If face mask, blot with paper towel or lint-free cloth.
    • If hose, rinse again with distilled water, then grasp by middle and spin in an open room.
    • For humidifier, rinse again with distilled water, then blot with paper towel or lint-free cloth.

  5. Reassemble.

ResMed S9: manual

ResMed S9: adjusting ramp-up

Mostly, I just wanted to turn mine up. Its default behavior, taking 4 minutes to ramp up to full pressure, was limiting when I was experiencing the respiratory distress due to a cold, flu, bronchitis, etc., like sucking air through a soda straw.

  1. Turn on.
  2. Rotate the Push Dial to bring display focus from Home, to Humidifier to the triangle-shaped Ramp-up menu.
  3. Press the Push Dial as if a button.
  4. Rotate the Push Dial again to select time for ramp-up from Off to whatever delay you wish.

ResMed S9: adjusting the pressure

Caution: this is ordinarily set by a medical technician based on a neurologist's prescription. Your mileage using these instructions may vary.

This is only "View Settings" unless it's the very first time getting into "Settings" immediately after turning on the machine. Here's how:

First, some terminology. See the image at upper right. If you click it, you can see it bigger. I'll be using their terminology for convenience.

  1. Turn on machine.
  2. Hold both the Setup menu button and the big Push Dial down at the same time for a few seconds. This will get you a new menu down the left side of the LCD screen.
  3. When you see the new menu down the left side, it should look similar to the one here at the right and you'll see some "gears." Rotate the Push Dial, if necessary, until you see the gears. In the main part of the screen, you'll see Settings.
  4. Depress the Push Dial to engage Settings.
  5. Turn the Push Dial until a faint rectangle encloses Set Pressure (or, on some models Max Pressure). The value you see is what the machine is presently operating at.
  6. To increase (or decrease) the pressure, depress the Push Dial again, then rotate it in either direction until you reach the desired pressure. Then, depress the Push Dial again.
  7. At this point, you can restart the machine.

Cleaning my CPAP...

I found, for around $60, this ozonator that runs through the air passages of my machine. I don't care to immerse my CPAP fully in some big, expensive machine to clean it. This works fine. I clean the bits that don't get ozonated air running through them by soap and water as I always have.

SolidCLEANER Premium Bundle Include Travel Bag
4.6 x 2.6 x 1.65 inches; 1.1 Pounds

It is cordless, holds enough charge for maybe 10 shots. It runs for about 20 minutes, you can smell the ozone, and then for 10 minutes more without ozone to chase out the ozone smell. There is a residual smell for a few minutes anyway when I use my CPAP the first time after.

I usually run this three times every Sunday.

Last I checked, Amazon was no longer selling or had sold out. Too bad. I recommend this product for its price, ease of use and apparent effectiveness. Note: ozonators contain a consumable that must be replaced (eventually). So, I will one day need to replace this.

ResMed S8 and S9: a burnt plastic smell...

With my S8, I always got this smell of burning plastic whenever my humidifier reservoir ran low. Fill it back up and the smell went away.

Not so much with the S9, but, because it doesn't hold enough water for more than one night, I always fill every night. (I live in the Rocky Mountains where the ambient humidity, especially in winter, is around minus 100%. This causes my sinuses to bleed, sometimes profusely, so a CPAP with humidifier is a boon not only to sleep, but to better sinusal health!)

However, last night, I did get the burning plastic smell from my S9. Of course, the reservoir was the first thing I checked and, of course, that failed to be the cause.

As the S9 is particularly modular, I began detaching the components. First, I ran it without water (still got the smell—duh), then without the humidifier, just the respirator component (still smelled).

Finally, I replaced the hose with a little-used, poorer grade one and the smell was gone. I didn't try this first because the state of hoses is more of a hygiene problem than a stinking car motor thing. Reassmbling each component, the smell was still gone. So I took the (heating) hose and ran soap and water through it. A small piece of orange plastic came out and went down the drain. When I reinstalled the heated hose and tried it out, there was no longer any smell and I slept with no smell starting.

I have drawn no conclusion other than that I was lucky (I do clean my hose periodically and I do have a back-up hose still in its package).

ResMed S8 Elite II: bad start button?

My ResMed S8 has been a total trooper, but it's beginning to be difficult to operate. I got it no fewer than 13 years ago.

It doesn't offer automatic on or off (a convenience I didn't know existed until I got my S9 5 years later).

And it has developed the annoying characteristic of running for two or three minutes when I turn it on only to shut off for a few seconds, then start up on its own again. (This is annoying because I'm "suffocating" for a few seconds during this time. It's like waiting for the other shoe to drop.)

The solution I have adopted to solve this second annoyance is to turn the machine off by unplugging it (or switching it off by a power strip). You might object to this thinking about the recording of hours slept and other data on the chip, but my attitude is that a CPAP helps me sleep—performing as a guinea pig for my neurologist's pleasure is a secondary luxury I don't care about.

Lately, however, I have begun to have trouble with my S8 should I need to stop it, then start using the buttons intended for that function. Read on...

When you have to push a long time, multiple times over and over again to get your S8 to turn off or turn on, what's happening is that the start/stop button contacts have aged, glazed over or otherwise are not making contact any more.

Behind (underneath) the buttons are two or three contact points, the little black dots you see in this image.

You will need to clean these dots. A long CPAP forum discusses various ways including

  1. ✗ Using an emery board to remove the glazing (bad, destructive)
  2. Using a pencil eraser tip to remove the glazing (non destructive)
  3.  ?  Cleaning each with isopropyl alcohol
  4. ✗ Cleaning each with WD 40

I used the second method with ease and success but, let's explore what all of this means...

These contact points short (make contact across) a printed-circuit conductor, two copper traces on the circuit board (there's a close-up of these for the start/stop button below). Each button has two or three contact points that actuate several functions (by one, same button).

This is the close-up mentioned above. I don't believe these ever need to be touched; it's the black, carbon-impregnated silicon dots (see above) that need reconditioning.

Accessing the button mechanisms isn't as hard you might think and there are no dangers (like explosing springs to lose or are hard to get back into place, etc.). All you have to do is use a small, flat-blade screwdriver by which you carefully pry the blue-plastic faceplate off of the S8 starting along the top edge, the edge that's almost covered by the sling at the top of the machine. Once you disengage it, it will lift easily off the machine usually carrying the rubber button assembly (one piece for all buttons) with it. This assembly removes easily and contains the little contact dots that you need to clean.

ResMed S9: disassembly and cleaning...

A T-10 Torx bit will take out every single screw in a ResMed S9 CPAP machine. Use a long handle because one of the screws is down a deep well too narrow for the shaft of a bit-driver to fit in. The only true way to clean a S9 and get rid of nasty smell residue like stale smoke is to take it completely apart, then thoroughly soak, wash, rince and dry the soiled foam padding blocks and rubber parts.

This model is by far more difficult to disassemble (than the S10). I took one completely apart, which was tedious, and had intended to reassemble it, but got the S10 below and so was far less motivated. Besides, I took it apart to clean the stench out and I found a lot of foam parts directly exposed to the airways. These foam parts, soaked and squished over and over again, were not losing their stench anyway.

So, I gave up and, unless replacement foam pieces can be obtained, I believe that attempts to clean are misguided, will ultimately be unsatisfactory and a waste of time.

Also, S9 machines "give up the ghost," with confusing messages about leaky masks, tubing, etc. that turn out not to be true and even purchases of new masks, cushions/pillows, tubing, connectors, etc. will not remedy the situation. Thus, the ResMed S9 is built to become obsolescent.

The ResMed S10 is very easy to disassemble and rebuild, doesn't involve foam parts that are in the airway nor cannot be cleaned. It appears that ResMed engineers and designers screwed up and built a great machine (even better than the S8). So far, mine hasn't crapped out and forced me to purchase a new one.

ResMed S10: disassembly and cleaning

I set out to clean a ResMed S10. It wasn't successful, but I succeeded in disassembling, cleaning and reassembling it without breakage or even deteriorating it. Click on any snapshot to see it bigger.

Here we go... the tools I used. Required among them, however, were the following subset:
  1. Torx 10 driver
  2. Tiny jeweler's flat blade
  3. Larger flatblade (for coaxing case apart)
  4. Cotton swabs (for cleaning)
  5. Slightly soapy water (ibid)
Here's the bottom of the case with all the details.
I removed the faceplate very gently. (I hate leaving tool marks.)
Here's the faceplate removed.
All the screws I needed to remove were identical and I kept them in a finger bowl.
After removing two screws at unit's back on the bottom, carefully separate, at the front of the unit, the top cover (or case) by prying gently.
Disengage the top cover carefully in order not to snag anything.
Here's the top cover. There's very little going on with it.
Looking from the back of the unit, we begin to see the large fan container.
Disengage the end opposite where the humidifier goes. Remove two screws on this end from the bottom. There's a circuit board with a 3-wire cable connecting it to the front circuit board. The connector for this assembly will be about the only hard thing in reassembling the unit later, especially if you're a bit fat-fingered as I am.
That connector now undone—with the unit lying on its face.
Still lying on its face, we're looking at the intake end of the fan casing now that the unit's end has been removed.
From the back looking down at the top, there's a screw to remove. Take a good look at what's holding things together, what mustn't be lost, etc. It's not as scary as you might think.
Pull the fan casing away from the unit. The only thing connecting it now is the fan's power cable to the front circuit board.
The fan casing is now separated from the unit. Note the three-wire power cable that arches over the top of the unit. This really won't get into our way.
Here's the fan assembly. The only head-scratcher is making sure to reroute the fan power correctly. (This is why I'm taking pictures, right?) Also, that piece of plastic with the water-marked arrow in it is peculiarly oriented and comes off. You'll need to put it back—the only thing I had to revisit my photos to remember how to do.
Remove the three screws holding the impeller plate to the fan casing and disassemble. Now we're seeing what must be cleaned. Mine had ample traces of metal powder (calcium, etc.) sucked into the unit from the air. They were put into the air by one of those ultrasonic humidifiers filled with tap instead of distilled water. (Where I live, we're lucky to see relative humidity in the teens.)
Here's a better close-up of the fan power cable routing again.
And again. Probably didn't need this, but I worried it would be a bigger puzzle for me than it turned out to be.
For cleaning, I thought I'd need to disengage this blue rubber boot from over the fan. It wasn't really true, but I didn't know that. Nevertheless, I recovered from having taken it apart.
But first, let's look at how it's attached. I used a small, flat screwdriver to coax these tabs through the fan impeller faceplate. Just be careful not to puncture anything.
I'm disengaging the rubber boot here. It's very flexible and easily cared for. Again, be careful not to puncture anything.
The boot removed, I did two things. First, I used a permanent black marker to remind myself where the fan power cable passed. Then, I washed the boot in warm water with dish soap being careful not to lose the mark.
Two things... There was a foam rubber pad to clean and dry, but it's not particularly part of the airway or flow (the blackish ring here). Second, the fan is in a sealed case that I suppose cannot be usefully cracked open. I don't have the technology or skill to ensure its successful reassembly even if I could crack it without destroying it.
(This is not the fan exhaust, but the impeller end.) The impeller blades were caked with white dust from an ultrasonic humidifer as well as the insides of the case. I reached down inside with a cotton swab to clean the blades and as much as I could reach inside the case—which wasn't much. This is why cleaning an S10 cannot be done to "new" condition with complete success. However, what I was able to do was successful enough.
I reversed the steps above though I didn't have the steps you're reading here written down yet. As I put things back together, I found I had to re-disassemble because forgetting screws here and there (so, make a better, ordered list next time). Also, that tiny white connector (bottom-most in photo) was a challenge for a few minutes.

All in all, the disassembly and reassembly was successful. However, not being able to clean inside the fan means that if an S10 stinks from cigarette smoke or some other environmental condition (smells inside a care facility, etc.), your trouble may be unrewarded.

Having "nothing to lose," I spun the impeller with an air compressor jet while squirting Febreze into it. This resulted in improving the odor (no tobacco smoke in my case), but after a few hours of using it,

If it were possible to purchase a new motor/impeller assembly for a reasonable price (I once saw one listed at nearly $600, but out of stock anyway), reconditioning a ResMed S10 to full, new status would be easily done inside of 60-90 minutes effort even the first time you had to do it.

If "brand new" is an absolute requirement, your only recourse is pretty much a new purchase.