December 15, 2017
In the article Sleep Testing – Alice Pdx, I wrote about the importance of being able to monitor breath flow rate to determine how well a person is sleeping. I explained how I’d used a professional grade Home Sleep Testing (HST) device called an Alice PDx to reasonable good effect. However, this approach is quite expensive and has serious challenges related to both the software and hardware.
In this article, I’m going to discuss a much simpler and less expensive Do-It-Yourself (DIY) Home Sleep Testing (HST) that you can repeat whenever you want without a doctor’s prescription. If I’d known this before, I never would have spent those many thousands of dollars on sleep studies, specialists, and an expensive PAP machine along with the hundreds of hours of research. I see now how basically simple this all is. Ugh; there’s always a “learning curve” to everything. In this article, I’m going to show you how to get good HST results using an inexpensive infrared camera, writst oximeter, and used PAP machine.
So it turns out that, as discussed in Do I Have A Sleep Disorder, the approach of taping a microphone under my nose and video taping myself with an infrared camera works pretty well. Although the image quality doesn’t need to be very good at all, the key is really being able to hear each breath. With this information, a person can review their video and knowing their own sleep and breathing patterns in general, get a good sense for how they’re sleeping.
Now granted, you can not see the actual breath flow rate curves, and aren’t monitoring other channels like heart rate and blood oxygen levels. However, as discussed in Sleep Testing – Alice Pdx, it’s mostly about being able to record breath flow rate. For now, I’m just saying that for a couple hundred dollars you can get a pretty good idea as to the quality of your sleep and then decide if you want to improve on your testing at a later outline.
So here’s my recommendation for recording infrared video. You need an infrared camcorder with and external microphone jack. Make sure whatever camera you’re looking at has both features. Also, don’t be surprised that even when you buy a camcorder with the right features that it’s going to work. I bought and returned two camcorders on Amazon before finally finding one that didn’t have issues, the DOCAM Night Vision Camcorder w/ Microphone . The battery contacts broke on the Brightworld Camcorder that I first bought, and the sound wasn’t synced to the video on the Besteker Camcorder that I purchased second. It could have just been bad luck as these are really budget cameras. As such, I’m sure there is a fairly high failure rate on them straight out of the factory.
When it comes to using the camcorder, I’d recommend taking a few trial videos during the day to get to know the various settings. You want to make sure that you install the largest SD card the camera can use and turn down the video quality setting to the lowest setting. In so doing, you’ll maximize the amount of video and sound captured. I found that the DOCAM Camcorder I’m using lasts about 6 hours before running out of storage space. I did by a 64Gb card only to find out that it can only use a 32GB SDHC Card. I suppose a person could get a second card and swap them out in the middle of the night.
By the way, the file size of video using the lowest setting is still huge. My old PCs really struggled to play these larger videos. It was bothersome enough that I ripped them all down to a much smaller size. I’m guessing this won’t be an issue for folks with newer computers.
Besides reducing the video size, the other all important setting is making sure the date and time are “stamped” on the video. This is just nice to have if all you ever do is infrared video and sound. However, if you decide to use a wrist oximeter or PAP machine as I’m about to discuss, it’s very important to sync the time on all of your devices and display the date and time directly on the video. That way, when you see irregular readings on the wrist oximeter or from the PAP machine, you can look and see what exactly was going on. Quite often, what otherwise looks like sleep disordered breathing is simply a person changing positions in bed – our breathing is a lot more erratic while awake in comparison to the regular patterns during sleep.
Taking a few trial videos on my budget camcorder, I found that I needed to reset to all the default settings and then tweak the video quality and date/time stamp settings every time before recording. For whatever reason, if the camcorder is turned off and back on, it forgets the date/time stamp setting. Also, if you try and go to turn this setting back on, the text on the menu selections is in gibberish. The solution was to simply reset all the settings and adjust the two that I needed to change just before pushing the Record button. Did I mention it’s a budget camera?
Here’s one last note about infrared video. It’s best if you can see your face regardless of what position you’re sleeping in. It’s helpful to be able to see if your mouth is open, to see movement in the neck and chest indicating effort, and the like. I cut a piece of wood with a 1/4″ threaded stud sticking out of it that I can screw my camcorder onto – there is a threaded hole in the bottom of the camcorder. The wood block and camcorder are attached to an overhead fan with a couple piece of nylon string. For those less inclined, “painters tape” that doesn’t leave behind a sticky residue is another alternative.
I found that the Lavalier Omnidirectional Lapel Microphone w/ Adapter Cable does a good job picking up those quiet, light breaths. I also bought a bag of Foam Microphone Windscreens and a 12-Foot Stereo Audio Extension Cable. I got the foam windscreens because I lost the original and also wanted to be able to replace them after sharing with other family and friends. I got the extension cable because you want to make sure you can wrap the audio cable a few times around something immovable. That way, if you inadvertently jerk the cable in your sleep, you won’t damage the camcorder.
By the way, all the camcorders I purchased used “stereo” 3.5mm jacks. In other words, when you look at the metal plug on the mic or cord you’re considering buying, make sure it has three electrical contact surfaces – the tip, one ring, and the sleeve. The Lavalier Lapel Mic w/ Cable I bought actually is made for Smartphones so it has four contact points – the tip, two rings, and the sleeve. Happily, it comes with an adapter cable that converts it over to three contact points. Note: I tried the less expensive Neewer Lapel Stereo Microphones but the sound was abysmal.
Take it from me; you want to make sure to double check all your microphone connections. Make sure they’re plugged in all the way. If you wake up in the middle of the night, double check the connection(s) between the mic cable and the extension cable. It’s very frustrating to wake up in the morning only realize you don’t have any audio.
In terms of attaching the mic, I removed the metal clip and taped a section of a toothpick to the mic that projects past the end of the mic and sticks through the foam windscreen. I then have a way to tape both ends of the mic to my face so it sits right under my nose. I tape the mic cable on one side and the toothpick on the other. Yeah I know; it’s crude but it works. Maybe someday I’ll epoxy on a copper wire to the mic that I can twist a loop onto the end to provide a bigger taping area.
The final piece of wisdom I’ve gleaned related to night time audio is that nearly all camcorders have what is called Automatic Gain Control (AGC). The camcorder automatically adjusts the sound level. In practice, when the video first starts, each breath sounds like a very loud windstorm. It’s so loud that the audio is clipped and distorted. In our situation, that’s totally fine. Audio fidelity is way down on the list; we want to be able to hear any subtle breathing.
After less than a minute, the Automatic Gain Control (AGC) turns the sound level way down. It does this so much that it’s hard to hear heavy breathing, let alone when breathing becomes shallow or gentle. I had to turn the volume up on my PC all the way in a quiet room to barely hear what was going on.
So you may think that there is a setting for this in the camcorder, but nope. You can only turn off AGC on some of the very expensive camcorders. There’s no mechanical work-around either. I eventually figured out I could use software like AvideMux to increase the sound volume. This is pretty old software so set a Restore Point on your PC before installing in case you have to remove it. I read you can also do this with modern VLC Player. Being able to really hear each breath is important.
OK, let’s say you recorded yourself and found out that you were struggling to get air much of the night. It was worse when lying on your back (supine) and you even stopped breathing all together from time to time. If you’re like most folks, you’ll dismiss it. Aw, I just snore a bit; that’s all…
If you value your health, don’t do this. Peruse the long list of symptoms related to aberrant sleep breathing in Do I Have A Sleep Disorder. Even if you’re somehow able to keep your blood oxygen levels above the normal 90% threshold, “sucking air through a straw” really damages health. Alright, I’m getting off of my “soap box”.
Getting back to PAP machines, I can be sort of “slow on the uptake” sometimes. What I mean is that I’d read about how Positive Airway Pressure (PAP) machines all are “data capable” nowadays. I even knew there was software from manufacturers like Resmed and Respironics along with the outstanding Sleepyhead software, created by JediMark, to be able to display this data in graphs on your PC. It just never dawned on me until “late into the game” to look and see if the breath flow rate curves from a PAP machine were any good.
It turns out that with Sleepyhead software, the breath flow rate graph from PAP data is better than my professional Alice PDx – Alice PDx Graphs. For additional comparison, take a look at the graphs from my expensive, state-of-the-art Dreamstation BiPAP AutoSV graphed using Respironics’ Encore Pro 2 software against the data from a used $150 Resmed Bi-PAP machine I bought on eBay using SleepyHead. There is no comparison.
Encore Pro 2 Screenshot
- Breathe Flow Rate
- Respiration Rate
- Tidal Volume
- Minute Ventilation
- Inspiration Time
- Expiration Time
- Flow Limitations
Looking at the screenshots, the Encore Pro 2 output doesn’t even contain a breath flow rate graph. In addition, it’s very rudimentary, not to mention much less user friendly. As I was sitting there one day admiring the SleepyHead graphs, and lamenting over the fact that SleepyHead doesn’t work with my new Dreamstation machine, a “light came on”. I wondered if a used, data capable, PAP machine that works with SleepyHead can act as an inexpensive breath flow rate monitor. The answer turns out to be “sort of”.
I say “sort of” because the pressure on most Positive Airway Pressure (PAP) machines can’t be turned down to below 4.0 centimeters of water. In fact, the lowest any non-pediatric machine will go is 3-20 cm of H2O – see the DeVilbiss Intellipap Standard CPAP. However, this machine doesn’t record breath flow rate.
SleepyHead Compatible Machines
- Respironics System One (450P models and above)
- ResMed S9 Families (not Escape models)
- ResMed AirSense 10 (0.9.8 and later versions)
- Fisher & Paykel Icon (data output isn’t quite as good)
- DeVilbiss Intellipap CPAP/Auto (no flow rate data recorded)
- Latest at SleepyHead CPAP Machines
Granted these are relatively low pressures, but their not zero. So we know the breath flow rate graphs are great but we’re stuck with having to apply a low continuous PAP pressure to get any readings. It’s not perfect, but it’s workable.
Just in case you’re wondering what would happen if you created a big enough hose leak to drop the PAP pressures even more, it doesn’t work. I made a PVC adapter that fit between the outlet on the PAP machine and the flexible hose. The adapter had a series of holes in it to let off the bulk of the air the blower is capable of producing. It turns out that when you do this, the machine loses all sense of your breath and ends up blasting high pressure into the mask that actually increase on exhalation. It doesn’t work.
So here’s the way I see it. If I had this to do all over again, I would have taken infrared video with audio as I slept. We know from a Sleep Disorders – Diagnosing & Impact that the video would show me working hard to get air. Seeing the video in combination with having a set of symptoms from Do I Have A Sleep Disorder, I would simply have gone online and bought a quality, used Resmed or Respironics Bi-level machine for a couple hundred dollars. Note: I’ll get into the details of my PAP machine experimenting in the next article, Sleep PAP Therapy – DIY.
I would not have spent thousands going to one of the most respected in-lab sleep centers in the country. I would not have spent thousands on the most expensive adaptive PAP machine on the market. I would not have spent more thousands on a professional grade Home Sleep Testing (HST) device. I would not have had to work to get prescriptions.
Instead, for about $500, with infrared camera, microphone, and used PAP machine in hand, I would have purchased all that I needed to monitor begin treating the Upper Airway Resistance Syndrome (UARS) I suffer from. Granted, even though I turned the Inspiration and Expiration pressures down to the lowest setting of 4.0, this is still a meaningful amount of pressure. It’s enough to help open the airway. Nevertheless, by comparing video shot with and without the PAP machine while wearing a mic in both cases, a person can get a pretty good sense of what’s going on, not to mention the fact that you’ve got a good PAP machine.
If you are loudly snoring, gasping for air, or micro-breathing, you’re going to be able to see this for the most part. You’ll also be able to compare PAP and no-PAP video. Let me give you an example.
Let’s say the video shows you’re breathing really quietly and you’re wondering if you’re getting enough air. It’s a simple matter to bounce over to the same time frame in the Sleepyhead data and see what you’re breath flow rate looks like. If the curves are nice and full, there is no problem. If they’re foreshortened or flattened, you’re not getting enough air. If you’re seeing flatten breath curves with a low level of PAP support, it’s pretty safe to assume that it’s even worse without PAP.
Likewise, let’s say Sleepyhead shows you stop breathing at some point. That’s not good. However, when you look at that same time in the video, you are clearly awake and just turned over. It’s not uncommon for folks to hold their breath upon exertion. These sorts of erroneous scores are common especially in Encore Pro 2 software. ALright, I know what you’re thinking; “Geez, could this get any better?” The answer is that it can.
Be Aware: I’m sure if they read this article that the medical community would be jumping up and down in protest to my suggesting that a person can test and treat less complex sleep disordered breathing on their own. After all, it is known that higher pressures can cause some people to actually stop breathing (central apnea) off and on during the night – whereas previously they didn’t have any apneas. In addition, there are more complex breathing issues such as the waxing and waning of the breath in Cheyne-Stokes Respiration (CSR).
However, we’re talking about really low pressures here. The chances of inducing central apneas, or any other issue, at 4 cm of H2O is next to zero based upon what I’ve read. In fact, pressures are not considered high until around 15 cm of H2O. Having your body interrupt breathing for a brief period until oxygen/CO2 levels re-balance is not a big deal. I say this because using the method I’m describing, you’d catch this the first night and besides, it happens all the time in sleep clinics.
From my experience, apneas (no flow rate) are often mistakenly recorded while I’m awake as I tend to hold my breath when I work to change position under my heavy bedding. If it turns out that 4 cm of H2O really does induce apneas, then I’d say there are some bigger issues going on. In my estimation, the risk is very low and it sure beats fighting with insurance and spending a lot of money.
Typical PAP Contraindications
- Bad dehydration
- Bad nose bleeds
- Risk of vomiting
- Lung disease – bullous
- Lung impairment – collapsed or emphysema
- Breathing is obstructed even when awake
- Acute sinusitis or inflamed middle ear
- Allergic reaction to mask material
- Low blood pressure – hypotension
- Cerebrospinal fluid leak, recent cranial surgery, or trauma
So just when you thought things couldn’t get any better, in steps the Contec CMS50F Wrist-worn Pulse Oximeter. In fact, the CMS50F is one of the oximeters that works with SleepyHead. Worn like a watch, this device has a sensor that slips over one finger. As you wear it, it keeps track of your pulse rate and blood oxygen levels.
So here’s where it gets cool and relates to DIY sleep testing. The SleepyHead software actually allows you to graph PAP data against data from a wrist oximeter. When you wear a time-synced wrist oximeter while using a PAP machine, you also get plethy, heart rate, and blood oxygen levels graphs. Note: I haven’t actually tried a wrist oximeter with SleepyHead but I have no doubt it works – see SleepyHead Oximetry. Remember, I’ve got an Alice PDx to measure oximetry.
SleepyHead Oximetry Screenshot
So now if we go back to the example of where a person’s breath curve was flattened and you could barely hear their breathe, with the oximetry data, you can look to see just what’s happening with oxygen levels. If the heart rate is going up and oxygen concentration levels are dropping, there is a serious air shortage. In other words, you can get a better sense for just how troublesome the issues are.
Wrapping It Up
I hate learning curves. By the time you get to the end, you know everything you need to make your life easy but it’s too late. If I had to do this all over again, I never would have left the comfort of my own home. An inexpensive night-time camcorder, a lapel mic, and a used PAP machine are all that I needed. Since I like experimenting and confirming data, I’m sure I would have bought the wrist oximeter too. Professional testing, new PAP machines, and medical professionals are great but if you’re willing to “roll up your sleeves”, there is a ton of data you can gather on your own. In my humble opinion, it’s enough for most to self treat – especially those that are like me and suffer primarily from mild obstructed breathing.