Positional Apnea - cluster events

[whiteoak]

    [attachment=25355][attachment=25355]     [attachment=25355]A few weeks ago, I learned that my "cluster apnea events" were most likely related to "positional apnea".  I started wearing a soft cervial collar, and saw an immediate improvement.  Now, on several nights, I continue to see these cluster events, even though I am wearing the collar.  My question is; are these still related to positional apnea?  I am wearing a 3 inch soft generic cervical collar.  I adjust it fairly tight, but not enough to be uncomfortable or squeeze my trachea to much.  I usually start sleeping in a supine position, with no pillow. I will then alternate from a side fetal position to supine.....back and forth throughout the night. 
I would appreciate your thoughts on this.
I am including an Oscar chart from last night.  Detail chart attached as well.
My AHI is about 2 on a good night and then 4 or 5 last last night. Cluster Apnea events are generally the culprit.
Thank you for this forum.  It is a wealth of information, especially to us newbees

[Gideon]

Those are likely positional, and extremely disruptive.

Can you easily tuck your chin under the collar as you are tossing around?

[mesenteria]

You may still be chin tucking, have a compressed or inferior padding under the cloth wrapper, an undersized (height-wise) padding that should be higher for you neck length, or your supine sleeping is of the really, really, bad kind...propped up with pillows, or even if it's just the one pillow, your head gets shoved forward enough by it its too high/firm/both.

I would be very happy seeing your initial improvement; that much must be gratifying.  But, with any one change, something else finds an opportunity.   You may be sleeping differently, not just 'better', and this is due to the changes you are engineering.  Your 'improved' sleep has something else taking place, and it may not be good.  We'll just have to keep tinkering...

[whiteoak]

    Yes, thank you, I agree with your suggestions, and thank you for confirming that it is related to chin tuck.  I have to work on a consistent method to prevent the chin tuck.  As you can see, I have very little chin, and I think that adds to the problem.
A few nights ago, I made a conscious effort during the night to make sure the collar was well under my chin.  I had no clusters that night.
I do not sleep with a pillow when in the supine position.

[Gideon]

We are not married to the collar.
Can you think of another way to prevent the chin tuck. Pillows beside your head, a buckwheat pillow with a light fill, no material under your head?