In my quest to find the ideal soft neck collar, I've bought my third collar recently, the Caldera Releaf Neck Rest (the other two were the Eliminator and the Carex Cervical Collar, which I reviewed recently).
The Releaf isn't sold as a medical device (contrary to Carex, which is), but is mostly intended to support your neck during travel or while you are working on a computer. Here's how it looks:
There are 2 versions available, a Regular size and a Large size. The regular is intended for necks measuring 12-15" (30.5 cm to 38.1 cm) and the large is intended for necks measuring 15,25 to 17,25" (38.7 cm to 43.8 cm). They both have a width of 1.25 " (3.2 cm) and a height of 3.5-3.75" (8.9 cm to 9.5 cm) however the design is made so that it gets thinner towards the back side of your neck (it decreases to 1/2 to 1/3 of its frontal thickness). While Carex was 0.83 " (21 mm) thick (so technically thinner), it does feel thicker, because its thickness doesn't change.
The Releaf has an interesting design, as you can see from the pictures. There are 2 creases, the upper one is concave and transverses the whole collar in an horizontal fashion. The lower creases are convex and end up in the middle. The presence of creases means that the collar is going to fold under pressure. Also, the sponge contained inside is significantly softer compared to Carex, so the amount of support provided by this collar is less than Carex. This could be a disadvantage if you have narrow upper airways, as they may collapse despite the presence of the collar. In my case, while I was able to flex my neck a few cms, it still worked nicely and I had my first 0 AHI night since I started CPAP therapy 2 months ago. Now, to be fair, I used it for just 2 nights yet, so the sample size is too small to draw any conclusions if it is working better for me compared to Carex, but it sure is more comfortable, because it is softer and the fabric is much more agrable to hold and touch. An interesting observation, that could or could not help some people, is that if you flip the collar upside down, you'll see that the part where the lower creases meet has nearly zero thickness:
So, if you wear it with this side up, there will be minimal contact area with the soft tissues under your chin, a problem I had when using the Eliminator (too thick, compresses soft tissues and blocks airways). Now, this might not work if your chin slips, but because Releaf is narrower (shorter) compared to Carex, it didin't slip for me. I wore it like this the first night (and to be fair, it was by mistake, I was sleepy and didn't pay attention how I was putting the collar) and my AHI was 0.7, so higher compared to the second night, but some of the events were recorded while I was awake, so my true AHI could be lower. Either way, this is something to try on, in case the regular side is too thick for you.
I'll continue using Releaf for a longer period and see if the results are consistent. Also, I am not sure how durable the product is yet, so that also need to be considered but as there was a request to review cervical collars, I thought it'd be useful to post my early impressions with it.