Record head position

Has anyone seen or experimented with the influence of head position on sleep apnea. I'm referring to if you sleep on the right, back, or left positions. Or your chin deep in the chest as compared to stretching your throat and looking to the stars.

As I tinker with motion sensors and electronics, I was considering if it could measure and record the position of the head and correlate this with your OSCAR patterns. It might explain why I have different patters in different periods in the night. Anyone had experience or interest in this?

dstahlberg wrote: ↑

Wed Feb 09, 2022 1:28 am

Has anyone seen or experimented with the influence of head position on sleep apnea. I'm referring to if you sleep on the right, back, or left positions. Or your chin deep in the chest as compared to stretching your throat and looking to the stars.

As I tinker with motion sensors and electronics, I was considering if it could measure and record the position of the head and correlate this with your OSCAR patterns. It might explain why I have different patters in different periods in the night. Anyone had experience or interest in this?

sleeping on your back allows your tongue to slide down partially into your throat, thus blocking airway which causes events.

chin into chest causes a bit of a bend in the airway, which can also lead to events. wearing a firm foam cervical collar while sleeping helps to keep the chin up.

so yes, positional sleep does have a bearing on sleep apnea. usually people are advised to buy a "cheap" video camera and record themselves over night to see where the data correlates.

i suppose it depends on whether your motion sensor build would be cheaper than said video camera.

dstahlberg wrote: ↑

Wed Feb 09, 2022 1:28 am

It might explain why I have different patters in different periods in the night. Anyone had experience or interest in this?

What type of patterns are you observing? Changes in number and/or length of events? Changes in pressure?

My own experience (using predecessors to OSCAR) during the early days of my CPAP use showed:

Highest pressure requirements - Back-sleeping
Much lower pressure requirements - Back-sleeping with use of foam cervical collar
Lowest pressure requirements - Sleeping on either side

I now wear a foam cervical collar to keep my neck in a neutral position. This is the best position for airway patency.

Here's a reduced example that may be helpful as you look at tooling up for motion and/or rotation detection and display. OSCAR presented my later Excel-massaged/converted datasets via its Somnopose import capability.

My experiments with accelerometers mounted on central forehead and on back at lumbar 2 or 3 near center of mass could not be found. Here's one of a few head-mounted examples. Typically there was much more head motion and rotation than near center of mass.

I haven't used the GDC-16 and X-2 3-axis accelerometers the past couple years. I did try wrist and ankle mountings, but stopped quickly because of interpretation difficulty and wondering how true Fit Bit and such portray core position and motion with sensing at the wrist.

I can't say, now, whether I had adopted the cervical collar which has long done wonders for my OA and FL. As I recall, supine was still a problem, as shown, with my Resmed Autoset and first 3.5 in collar. I've used a Resmed VAuto and 4 inch collar for so long, with few scattered and small FL, I don't know which, collar or VAuto, to give most credit for long-time 0.2 AHI. I have found virtually no increase in FL after continuing with the collar and quitting use of an effective supinity block.

Interpreting the blue trace for the spine-cranium axis takes a bit of thought and challenges my recall. It looks like the blue trace shows my chin was tucked about 20 degrees from 0600-0700 when supine (red trace). At about 0820 my cranium axis must have been about level with the bed plane at the peak 90 degree angle.


The green trace presents "seismic" burst intensities and amplitudes of motions relative to gravitational force 1.0. The accelerometer's sensing accuracy is a bit anisotropic, varying some among x, y, z coordinates. Ideally the green axis would be on the zero line, the night through. All three axes are smilarly affected, but not a serious problem.

The 1-hour time offset and date indicate I had not changed the Autoset to PDT.

Sorry for being late to answer. Thanks for all the comments!

Seems there are several variables to measure (body position, head position) and on several axes on the head. My initial idea was to fit an accelerometer/gyro-IC on the front of the mask and attach a cable along the hose (running to a small computer). But now I see there are several options.

Also, there is the problem of using the information - OK, let's say you find that 50% of the night you sleep on your back, and that's the top interval of AHI. I really can't order myself not to sleep on my back ??

I guess I have to think a bit more on my goals and how to reach them. There's a Swedish expression "gå inte över ån efter vatten" - don't cross the stream to get water.

dstahlberg wrote: ↑

Thu Feb 17, 2022 4:11 am

I really can't order myself not to sleep on my back ??

No, you can't. But you can do some things to discourage back-sleeping. There is the old backward-worn-pocket-tee-shirt-with-a-tennis-ball-in-the-pocket tactic. I wore a small backpack stuffed with junk for a while. There are similar things sold commercially - https://www.amazon.com/s?k=back+sleepin ... _sb_noss_1

Some claim to position pillows to prevent back-sleeping.

Whatever you try, it is often difficult to accomplish.

On a personal note, I found wearing a firm foam cervical collar accomplished as much as avoiding back-sleeping. The collar holds the neck in the optimal position for airway patency and prevents the chin from dropping toward the chest.

So, this thread is NOT about fine-tuning my audio equipment?
(Sorry, I simply could not resist!)

chunkyfrog wrote: ↑

Fri Feb 18, 2022 10:55 pm

So, this thread is NOT about fine-tuning my audio equipment?
(Sorry, I simply could not resist!)

No, and it's not about the guy who ended up in Guiness Book of Records for turning his head 110 degrees to the right right either

dstahlberg wrote: ↑

Wed Mar 02, 2022 1:18 pm

No, and it's not about the guy who ended up in Guiness Book of Records for turning his head 110 degrees to the right right either

Although he never snores anymore...

dstahlberg wrote: ↑

Wed Mar 02, 2022 1:20 pm

dstahlberg wrote: ↑

Wed Mar 02, 2022 1:18 pm

No, and it's not about the guy who ended up in Guiness Book of Records for turning his head 110 degrees to the right right either

Although he never snores anymore...

At my first sleep study when I was asked to sleep on my back - I got a towel from the bathroom, rolled it up and wrapped a rubber band around it. For those who have ever done CPR you will recall hyper-extending the airway? So with that in mind I placed the towel in the nape of my neck and let the PSG begin.

I remember that was better than my other sleep position which allowed my chin to go to my chest.

IMO a pillow will almost always put your airway at some angle.

When you are out shopping look for some of the seniors walking around with the hunched shoulders and neck - you can almost bet they sleep with more than one pillow.