Sleep Positions: Model X16-1C Accelerometer

I wear the Model X16-1C accelerometer at night, Velcro'ed to the top of my Quattro FX head gear.  The mask head gear is conveniently made to accommodate Velcro because that is how the head gear is adjusted.  I put the accelerometer on the top of my head because there's a strap there to attach to and it's out of the way of my nightly movements.  The accelerometer records X, Y, and Z positions into text files from moment to moment, which I capture and record into a database.

I "calibrated" the meaning of the X, Y, and Z values by putting my head and body into known positions for a while and then looked at the values.  The chart below shows last night's data with some notations about sleeping position.

From this data I can tell what sleeping position I'm in when and how often I'm changing positions.  In the beginning I go to sleep on my tummy with my head to the left, but later, in the middle of the night I tend to roll onto my back, then back on my side again, and back and side... etc.  Near the end of the night you can see that I'm starting into a waking process during sleep as on the far right I become more active, changing positions / moving frequently.

In another posting later I'll show how I relate positions to my brain waves from the Zeo and my breathing and apnea events.

Model X16-1C Accelerometer

As I mentioned in a previous post, "BasementDwellingGeek" at cpapTalk.com talked about an accelerometer for measuring movements during sleep, breathing, sleeping positions and I suppose numerous other things.  My interest is in sleeping positions.  It is the Gulf Coast X16-1C Accelerometer for $89, plus shipping.

When I received it this is what I found in the box...

The blue device at the top is the accelerometer itself and the black item below it is a rewindable USB cord, very handy because the accelerometer is actually a USB thumb drive (aka RAM drive, nice for getting your data!).  The rewindable USB cord is handy as it could be difficult to plug the accelerometer directly into your PC in close-quarters.  It shipped with a necessary AA battery and a screw driver too, so you could open the accelerometer and put in the battery.  They sent everything needed to fire up the unit.  I was expecting just the blue accelerometer.  I got more than I expected, smart on their part.  You have to put in the battery paying attention to which direction the (+) terminal goes, then you will find that the manual is on the accelerometer's thumb drive when you plug in the accelerometer to the USB (and the drivers install).  The only suggestion I would make to Gulf Coast is to put a little slip of paper in the box describing how to put the battery in (which way) and that the manual is on the RAM drive.

The accelerometer's case is just right.  Rounded corners, no wires dangling, no connectors and a nice cap over the USB connector.  It's 3-4 inches long and probably less than 1" wide and deep.

Since I was interested in sleeping positions, I needed a way to attach this to me.  I had some velcro straps I was not using so I rubberbanded the accelerometer in the velcro and then attached it to my CPAP mask headgear, which is velcro-friendly, that's the way you adjust the straps on the headgear.

Good.  It is actually secure.  It's hard to remove the velcro from the headgear.

Configurable
This device is configurable by adding/changing/removing configuration settings in a text file to customize how often it records values, the number of readings per text (CSV) file it puts on its RAM drive, numerous others. You have to use WordPad in Windows to do this, not Notepad (so they say).  Something about proper line terminations (Carriage Return Line Feed stuff).

XYZ
The nice thing about this unit is that it senses and records gravitational G's.  That means it's recording positions, not just movement.  If you have it at different orientations, it's recording different G's on it's X, Y, and Z axes thus different X, Y, and Z values. So, if I strap it to my body / head and rotate my head, or roll from my tummy to my back when sleeping, there will be levels of X, Y, Z that correlate to those positions. Perfect!

Surprise Bonus... Temperature
Come to find out when this unit writes files it records the temperature for each file following the hour change.  Who knew!  Great!  Now I can have my sleeping temperature too!  Perfecto!

More later on the XYZ and sleeping position with some graphs...

Until then.

New Toy: Accelerometer

On a recommendation by "BasementDwellingGeek" at cpapTalk.com I got a new toy... an accelerometer.  It is Model X16-1C made by Gulf Coast Data Concepts in Waveland, Mississippi.  Here's the web page to the device:

Gulf Coast X16-1C Accelerometer

It cost me $89, plus shipping.  Is it worth it?  For me, clearly yes!

Why an accelerometer?  Well, it clearly tells me my sleeping position.

In the coming days I'll write up what it looks like, what I got with my order, how I set things up to use it, the data it generates and what it is telling me.

Equipment

I have a variety of equipment that I am using and I might get more, we'll see.  Here's my list:

• ResMed S9 AutoSet. This is a medical device that is a fully data capable auto positive airway pressure (APAP) sleep apnea treatment system.  It applies a varying air pressure to my face using a sealed mask, which forces my airway open if it needs to as I sleep.  This device gives me information such as:
  * Event Flags: What kind of breathing event I have, when it occurred and for how long
  * Air Flow Rate as I breath in and out
  * Mask Pressure which varies as the machine tries to eliminate events
  * Tidal Volume which is the amount of air I'm breathing in and out
  * Minute Ventilation, similar to Tidal Volume, but the amount per minute.
  * AHI, an index that reports the events/hour.
  * Leak rate (how much the mask is leaking)
  * Snore Index (how much I'm snoring)
  * Respiration Rate (breaths / minute)
  
  Data from the ResMed S9 AutoSet is from an SD card, which you pop out of the ResMed S9 AutoSet and put into a card reader in your PC.  Presently, until I can get this data into our software, I use SleepyHead to view trend charts with it.
  
  Note: I highlight the word AutoSet because so there is no confusion with other ResMed "Auto" machines that are not necessarily data capable.
  .

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• CMS 50 E Pulse Oximeter.  This is a that device clips on my finger and as I sleep it records my heart rate and blood oxygen levels (spO2).  It is not a medical device, and is therefore not very accurate, but good enough to know what is going on.  The pulse rate is reasonably accurate.  The spO2 is within 2% when above a 70% spO2 reading.
  
  Data from the CMS 50 is available through a provided USB/Serial cable and the data can stream from the device in real-time, or the device can store it for up to 24 hours each session and then it can be transferred to your PC using the provided USB/Serial cable.  It comes with two software applications; real-time and session review (SpO2 Review).  I use the latter to fetch sessions off of the device and the SpO2 Review application dumps the data to disk, which then I import into our software.
  
  Available from Amazon (?) or the PulseOxStore.
  Software and the device driver, if you need them, may be found here at the PulseOxStore.
  .

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• Zeo Bedside Sleep Management System. (psst... you can get it cheaper on Amazon).  A rather cool non-medical device that has a headband that you wear and it measures electrical activity through the skin on your forehead.  This activity is in part facial movements but principally your brain's frontal lobe electrical activity.  The Zeo Bedside gathers this data in a fancy alarm-clock and generates various information about your sleep, most notably crude, but generally correct, estimates of what your sleep stages (Wake, REM, Light and Deep) were during the night every 5 minutes. It is computing this every 30 seconds based on frequencies calculated every second, based on a brain electrical activity measured 128 times per second.
  
  Data from the Zeo is available either through
  
  * An SD card, on which there is a night's sleep session, which then can be transferred to your PC, uploaded to their web site and used in a user friendly sleep coaching system with lots of interesting charts, statistics and such.  You can also download data, summarized by night, to your PC again in a CSV file, one column of which has 30 second sleep stage estimates.
  
  * A serial port in real time.  The Zeo does not come with a USB/Serial cable however, you must make one. :(  I did and I'll tell you how.  And when you do make one, there is an application called ZeoScope that enables you to see your brainwave and the amplitude (I think) of Alpha, Beta (1, 2, 3), Delta, Gamma, Theta frequencies the impedance of the band on your skin and also the sleep stages the Zeo is estimating.
  
  Presently, I use both the SD card / web site to get Sleep Stage charts and a serial cable to collect the real-time stream into our software.

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•  X16-1C Accelerometer by Gulf Coast Data Concepts.  Tells me the orientation of my body and head while I sleep, such as on my belly, head to left or right, or on my back, head left or right.  This device confirmed without a doubt my positional sleep apnea.
  
  This device is not only an accelerometer, but a USB thumb drive that contains the data it creates in text CSV file format.  Spiffy !  Easy.