Bubble CPAP chin strap help!!

Looking for some help here...

Our unit uses bubble cpap. We have been struggling with ideas for chin straps on our babies who continually have their mouths gaping open, and thus stop bubbling and lose their pressure. We used to tie stockinette (the very stretchy white kind) around their chin and over their head ... you know, the old 'bunny ears' approach, but we had a couple of events in the past with misuse (tied way too tight) leading to molding and now our management is trying to come up with a better solution.

The current idea is to fold a piece of non-stretchy cotton and tape it under the chin and onto the hat. We have had HORRIBLE luck with this - since the hats are stretchy and the tape sticky on the baby but never for long on the hat. I go into the bed with the baby desating to 60s, not bubbling, to find baby with wide open mouth, tape stuck to hands and face... Or to find that when crying, the baby has pulled on the chinstrap and thus pulled down the hat which pulls the cpap prongs out of the nose... ug!!). I keep thinking that we should be able to come up with a separate chin strap product/idea that would not interfere with our cpap hats (which are tough enough to keep stable without adding chin straps holding strong jaws)...

What are you all doing?? Very specific information please - including manufacturers if you use manufactured products.

Thanks in advance!!!

Rainbows