The DreamStation Foam Removal Thread

[shlevinemd]

I've been ill for 10+ months and am fairly sure this is the cause.Therefore,I wouldn't use the dream station again regardless of what is done to correct the problem Incidently I've lost 25 pounds in the last month due to early satietv and nausea, I apparently no longer snore!

[KJ Gilmore]

Has anyone looked into using 100% silicone aquarium sealant to close the hole made to remove foam?  My husband thinks it would be safe once cured.

[mrmagloo]

Has anyone looked into using 100% silicone aquarium sealant to close the hole made to remove foam?  My husband thinks it would be safe once cured.

I am sure there are dozens of possible solutions.  Again, the easiest, and most elegant method so far seems to be the 1/2" hole with a step drill, and using the 1/2" PE salt shaker plug to reseal.  The key here is, you have to create a large enough void to reach and extract the foam, yet have the void clean enough to be easily resealed.  I like the PE salt shaker plug trimmed idea as it's the same material as a milk jug, totally inert, and completely harmless. Perhaps you could use silicone sealant to circle the plug to ensure it remains locked and is air tight - instead of using the aluminum tape seen in the photos earlier in this thread.

[remseeker]

After removing the foam in my DreamStation BiPAP autoSV machine on Sept 29, I haven't detected any changes in its operation using my 6/4 pressure settings, and OSCAR results seem in line with those before the de-foaming.

I used rocketrobo's method of food grade plugs and Raybee's suggestion of a step drill bit ("IRWIN Unibit Drill Bit, Single Hole Size, 1/2-Inch -10310" about $22 from Amazon.).

I held the chamber in a jig with a plywood base (see picture) to help assure that the step bit maintained good alignment as the bit came back up through the drilled hole. I drilled a 9/64 inch pilot hole for the step bit. The plywood base was clamped to my drill press table.  (If I had used a hand drill, I think I would have stopped rotation of the bit before drawing it back through the hole I had drilled.)

For foam removal, I used a curved-end hemostat and a pair of needle-nosed pliers.  To help in pulling out the remaining larger pieces of foam, I used a length of slim, flexible metal which was removed from a discarded wind shield wiper blade (available in the garbage cans outside auto parts stores).  Thin segments of foam remained glued to the top of vertical walls inside the chamber, but at least now there's much less foam to worry about.

After the drilling, there were some short strands of chamber plastic to detach from the bottom edge of the drilled holes.  I did not trim the plugs to a shorter length or use any tape over the plugs. The top of the salt shaker plugs seated snugly against the chamber surface.

To test for plug air leaks, beads of water were deposited around each plug and pressures of 6 and 15 cm H20 were tried, using my hand over the mask outlet to maximize pressure.  No air bubbles were observed around the top of the plugs, but I'm not sure I did this test well enough as it was difficult to get a bead of water around the plug hidden under the circuit board. 

Before re-assembling my machine, I washed the chamber several times with warm water to hopefully remove foam particles created by my drilling, and then let it air dry for about three hours.  

During disassembly, a ribbon cable connector (connected to the separate speaker circuit board) popped out of its socket on the motherboard, but it was easy to reseat the connector in the tiny surface-mount motherboard socket.

To avoid possible static electricity damage to the motherboard, I touched a grounded metal surface as I worked, although my house humidity level was probably high enough to inhibit static buildup.  In low humidity conditions, I think many people would use a grounded wrist strap, such as the following two items from Amazon - "Vastar ESD Anti-Static Wrist Strap $5.39 (cord has built-in MegaOhm safety resistance)  and "StaticTek Banana Jack Outlet Plug Adapter" $7.97 .  I would think that assembly of these machines at the factory is done with ESD protections.

Thanks again for all the de-foaming information!  And thanks to Zalagar in post #90 for adding his re-sealing precautions.  

Off-topic, but I really wonder how likely is that DS1 ASV machines will be repaired. Someone in my doctor's office said that ASV functionality in DreamStation 2 machines is not yet available, which I guess may be due to a greater need for the DS2 Auto machines compared to DS2 ASV machines.

[LindanHotAir]

If you use plugs, be sure you trim the skirt almost flush with the bottom of the plastic. If you don’t trim them they whistle and create turbulence that disrupts the laminar flow through the flow sensor slots. The flow readings were way off until I trimmed the plugs.

[mrmagloo]

Here a photo to help everyone envision the plugs everyone is talking about. When you buy them, they come in a 4 pack, so you end up with 2 extras.

In this photo, I drew a red arrow at the place where is seems to make sense to use a straight edge razor to trim the legs of the plug, as you only need one rib to get past the create hole to lock the plug in place.  Any parts past this may create turbulance.

I hope this helps folks visualize what we are talking about.

[DaveCar]

Nice writeup Remseeker, complete with part numbers and a jig even.
The circuit board ribbon cables and ESD (static shocking the circuit board) are probably the biggest 'hazards' to the job.

I wonder if yourself, or anyone else that has removed the foam, could try some 'tests' on the foam.
It would be beneficial to find out if there is a way to "melt" the foam in place using common household things, and thus be able to just "pour" the foam out of the chamber.
Will it fall apart/melt in hot water ? Vinegar ? Anything ?

[remseeker]

Hi LindanHotAir,  

Since you mentioned having problems with plugs not trimmed off, I double checked my situation of untrimmed plugs and can't identify a problem with whistling sounds or any significant changes in my OSCAR "Flow Rate" or "Tidal Volume" readings after foam removal. 

In addition to 6 cm H2O, I tried a pressure of 15 to try and detect sounds of turbulence with my 76 year-old (high-frequency-deficient) ear against the top of the machine, but could only make out blower motor sounds.   

Could you provide a little more information on the flow readings that you said were "way off" for your machine?  

Maybe since my pressures of 6/4 are lower than your pressures of 12.2/17.5, and since I have a different machine (DreamStation BiPAP autoSV) where yours is a DreamStation Auto machine, then those kinds of differences might explain what's going on.  Or, maybe I'm missing something and need to fix the plugs using mrmagloo's helpful picture in Post #96.

I'm hesitant to take apart my 1 1/2 year old, Medicare-covered ASV machine again to trim the plugs if I can avoid it.


Thanks for any help.

[remseeker]

LindanHotAir - Are the holes that you drilled near where rocketrobo in his Post #60 (this thread) had his located?  That's where I drilled my two holes also.  I wonder if the locations of the 2 two-port sensors relative to where my two untrimmed plugs are located could be a factor in my not seeming to have turbulence problems? (Thanks to qwerty42 in the RECALL THREAD post #567 for his great explanation of sensor operation!)

In hindsight, I guess the best thing would have been for me to have paid attention to what mrmagloo suggested in his Post #65 and trimmed the plugs.  Hopefully I won't have to do this later on.

[Zalagar]

Hey all. I just Defoamed a 2nd Dreamstation for my uncle, as his insurance wouldn't help him out and his doctor told him to just use inline filters, which sucks and are miserable to use. I used the coat hanger method just like I did on mine. No cutting. I have all the foam out now and will be keeping it for testing methods. Let me know what you guys would like me to try to use on it. I know someone had been asking about boiling water. I will try that shortly. I can only really try out stuff I have on hand, don't have the funds to go buy stuff, but if you think of anything else you'd like me to try, let me know.