I've used F&P's ESON2 nose mask (medium) for around 10 years. I want to make you aware, if you're not already, that this mask is defective in the following way:
Easily broken harness-retaining-clips.jpg (13.06 KiB)
Most of the mask framework is made from molded clear acrylic. While generally strong when thicker, F&P have made the upper harness retaining clips very thin. And thin acrylic snaps very easily, making a NZ$250.00 mask useless.
I first brought this to F&P's attention about 12 months ago. They did nothing which I suppose could be a good cash cow for F&P. But perhaps it's just me, and I'm not treating the the mask harness clips gently enough. I dug deeper and found that the Manukau Superclinic in NZ, which has an excellent loan service for CPAP machines, has had a number of ESON2's returned with the same kind of breakage.
I received a corporate-speak email from F&P's sales manager again about 1 month ago and they say "they are looking into it". Yeah, right.
I decided to make a new stronger clip-retaining fitting, initially from brazed copper. It is ugly but it works. All the mask problems went away. The smarties among you may be able to model and 3D print this in a stronger plastic. Image below.
An ugly Eson2 modd that works - eson2-modd.jpg (25.54 KiB)
The prototype is made from copper plumbing offcuts that slip over the "stump" of acrylic (after grinding off the jagged remains of the broken clips) and is firmly held there by a soft plastic splint pushed down between the central copper tube and acrylic stump. Two (upper) harness clips are brazed to the tube sides.
Repeated heating of copper to soften it helped the bending process to a rough clip shape. After cleaning with isopropyl alcohol to remove skin oils, I sprayed it with 2 coats of black anti-corrosive paint. To remove the copper clip, gently push the whole thing upwards with your thumb until splint releases. No glue is necessary.
It works like a charm and, as with many of my projects, I learned as I walked the walk. Next time around I would use flux-core silver solder and wire-wrap the 2 clips to the tube with copper wire, BEFORE soldering and bending the clips downward. Holding the clips on the tube while brazing was the most awkward part. Wire wrapping would relieve you of being supernaturally steady-handed.