Why is capnometry biofeedback not more widely known?
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I came looking into this topic because I have severe breathing issues that were caused as side-effects of neurofeedback that was supposed to help trauma issues. Ended up doing a lot of butekyo, but that didn't help me at all and wanted to know why. Somehow found out about this co2 stuff and saw the same issue about how expensive it was and how little people knew about it.
With lots of searching I found this meter about 2 years ago and have had it since: https://contechealth.com/collections/best-selling/products/contec-ca10s-end-tidal-co2-capnograph
As far as I can tell it seems reasonably accurate as the reading match what you would expect. As in breathing normal gives me values that are considered normal, and breathing too fast gives me the types of values you would expect for that.
Haven't been able to resolve my issues, but I was able to figure out more about what is occurring with it. My issue seems to be that my body thinks is a good idea to breath at crazy fast speeds from moving my body even just a little. I can for example breath at 30-60 breathes a minute just from typing quickly which will lead to feel awful really quickly, and similar results for other physical activities. Which will indeed mess up co2, but isn't the same issue people normally have so hence butekyo not helping.
Thank you, this is really fascinating! After writing this post, I talked to someone who does biofeedback using a capnometer, and they also mentioned that same CONTEC device as a cheap but still accurate capnometer. Their main gripe with it was that it responds more slowly compared to the CapnoTrainer and doesn't show the wave form, so it is not as good for doing biofeedback with (e.g. apparently the CapnoTrainer can show things like aborted breaths or weird exhalation patterns, whereas the CONTEC device can't show that), but it is still good enough for det...
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The contec does show the waveform, it's just on a tiny screen so not the most detailed.
Talking is really bad too for me. If I talk for a sentence or less, let myself breathe a few breaths while not moving, then resume talking and keep pausing for a while after talking only a bit that helps a lot. For moving I adopted a similar tactic in that if I only move for a few seconds and then stop moving to breathing 1-2 breathes with no movement it stops the crazy breathing acceleration and tensing from happening. Doesn't solve it, but makes the bad effects much less.
I also had a lot of trouble eating, and was able to resolve that by very carefully watching my breathing patterns while eating, and figuring out how to modify them to be what would make sense to me as normal. I don't recall the details clearly, but I think I was not stopping during the eating process to breathe through my nose and maybe holding my breath for a long time and then going into faster breathing to compensate afterwards.
I too heard about the CaponoTrainer, and looked into someone renting me it and doing training with it, but I reasoned that whatever I had was highly atypical and there was a good chance there short very expensive training and rental would just leave me with a lot less money, and that was part of how I ended up buying that machine.
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Huh, okay, that is good to know. I was looking at images like this one where the wave form is clearly the SpO2, rather than CO2:
But scrolling through more of the images, I do see this, which looks like a CO2 curve:
I am guessing there must be some way to switch which graph you see?
This sounds so much like me... (Luckily I don't seem to have the problem with movement, but eating (specifically swallowing) makes me nervous too.) I don't know if you've looked into Peter Litchfield's work (he has a bunch of videos on YouTube too), but he talks a lot about altering your subconscious/unconscious breathing habits instead of consciously using techniques as crutches to save you from an episode. I recently got access to a CapnoTrainer so that will be my plan for hopefully fixing my breathing (I already did this once when going from ~80% nose-breathing to ~99.9% nose-breathing -- it took about a month of anxiously paying too much attention to my breath, but after a month or so it became totally natural).
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From my unit I can only get the graph to do co2 and nothing else, maybe some marketing person made graphics that aren't accurate, because I do recall seeing that image too, but didn't know what it was of and assumed it was co2. But the actual unit has no way of making a graph of the spo2 as far as I can tell, certainly not mentioned in the manual that you can. It just does the spo2 % number like shown on the screen.
I'm familiar with the CapnoTrainer there are lots of good videos out there describing what they do in detail many created by the founder I think. They are what convinced me that I probably have a problem that is unique enough that it's probably not wise to pay for their expensive service. Could have sworn it was around $2k for rental for like a month and a person helping you for a few hours because the rate for the person is around $250 an hour and contributes more to the cost than the rental. I can change the way I breath in various ways, but it makes things worse because my nervous system seems to force itself back into the old pattern and that process is always brutal on my body as it gets much worse as it finds it way back to the old way.
I had a couple instances that suggest what is stuck in my body is very much like trauma energy. I found by accident various ways to manipulate my breath that the later had the effect when I laid down it would feel like the energy from the tension in my abdomen was slowly moving to my arms, legs, and jaw/face over several minutes to 30+ minutes. I'd end up buzzzing with intense energy and feel locked down in those areas at the same time. It would feel like what I've experienced if in a life threatening situation and the body mounted intense energy to defend itself and then at the same time froze because it realized it was too dangerous to fight. If the energy can pass through my body then the symptoms will probably stop. Haven't been able to figure out how to get it to happen, if I move especially early on when th
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I had a couple more questions about the CONTEC device:
1. What's the lag time from when you breathe to when the waveform is displayed on the screen, and when the number updates?
2. How does it prevent water (from exhaled air) from getting into the device? The CapnoTrainer uses water traps inserted between the cannula and the device itself, and these water traps need to be replaced every once in a while. But I haven't seen anything similar for the CONTEC device.
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It can seem real time, but if I do an experiment such as breath hold or other big breathing change and wait till I see it, it's about 5 seconds from memory.
For the water I use these types of tubes: https://contechealth.com/collections/hot-sales/products/tube-adapter-for-co2-module-etco2-capnograph-respiratory-cable-for-cms8000-vet-veterinary?_pos=3&_sid=3eab643da&_ss=r
They remove the water, using that gold color threaded thingy in the tube it attracts the water vapor and releases it out of the tube, but not perfectly, when I stop if there is still water in the tube -- which is very often especially if used in the Winter with low humidity, I leave the machine running without me being plugged into it from 5-30 minutes depending on how much water was in the tube to help clear it because without the airflow it won't clear out.
I also figured out you can reuse the water filters by just ripping the ends off the tube they are just forced onto a tight connection. Then you can have cheaper cannulas without it and cut a spot on those and force it back on. It works better than expected because water filters are not permanently attached its just by tightness of the connection. Then if you throw out a cannula for sanitary reasons you can just take out the water filter and use it with another new one, I also experimented with attaching two of them on one cannula to make the filter even more powerful and it seems to work without messing up the readings as far as I can tell. Not sure if it actually works better, but I use it that way now.
If you end up buying it and the cannulas to get the best price look on that site, ebay, and aliexpress and buy whatever has the best price. I can also probably sell you some tubes with and without filters if you want them for really low cost way below what they sell them at because I bought way too many, though they are probably close to expired based upon the date they put on them -- can tell you the exact date if you want to know.
I on
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Thank you, this is helpful!
I found someone in my local area who has a CapnoTrainer and was willing to rent it out to me and coach me, so it was a lot cheaper than the official route. But yeah, in general rentals are quite expensive unfortunately. If I couldn't find anyone who would rent one out to me for a reasonable price, I would probably have just gone with the CONTEC device as you did.
When I originally wrote this LW post, I had never used a capnometer of any kind (it just seemed quite promising and I was confused why basically no one was talking about it). After writing the post, I found someone who would rent a CapnoTrainer to me, and have been using the device now for about a week. The CapnoTrainer is still the only capnometer I have used. It's still too early for me to say whether the device "worked" or not, but so far it's been a quite promising experience (I'm planning to write more in maybe a month when the rental period ends).
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Also going to add the ones I bought on amazon that didn't work were much thicker than the contec ones, the connector did work though, but I think the thickness of the space in the tubing may need to be the same perhaps to work, and the contec ones are very narrow. Thicker ones are probably for oxygen delivery and other uses and not co2 reading.
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Hi, I wanted to give an update. Capnometry biofeedback worked better than I expected. My baseline ET CO2 went from around 27mmHg to around 40mmHg in the first 1.5 weeks of using the device, and stayed there for the whole month I had access to the device. (I've now returned the device.) The key thing I discovered was that even though I was already nasal breathing 99.9% of the time, my nasal breaths were still quite audible and so I was overbreathing because of that. The biofeedback+coaching allowed me to switch my breathing to a silent nasal one in stages. I still experience air hunger, but it is a lot more subtle than before. I still have trouble talking, some of the time (I think talking makes me overbreathe, so if I start out with no air hunger then I can talk for quite a while, but if I start talking when I already have some air hunger, then I quickly reach my limits). I still on occasion mysteriously have a lot more air hunger than normal and feel like I "forgot how to breathe", and I wonder if that means I have some sort of autonomic problem... I've been writing up a lot of my thoughts here. I might retry capnometers in a few months or a year or something, but for now my plan is to go back to (original Russian-lineage) Buteyko method and really logging the time (rather than half-assing it, which is what I was doing previously with Buteyko). Feel free to ask any questions.
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It could be using nonlinear optical shenanigans for CO2 measurement. I met someone at NASA using optical mixing and essentially using a beat frequency to measure atmospheric CO2 with all solid state COTS components (based on absorption of solar radiation). Technique was called optical heterodyne detection.
I've also seen some mid IR leds being sold, although none near the 10um CO2 wavelength.
COTS CO2 monitors exist for ~$100 and could probably be modified to messure breathing gases. They'll likely be extremely slow.
The cheapest way to measure CO2 concentration, although likely most inaccurate and slow, would be with the carbonic acid equilibrium reaction in water and a pH meter.
Ultimately the reason it's not popular is probably because it doesn't seem that useful. Breathing is automatic and regulated by blood CO2 concentration; I find it hard to believe that the majority of the population, with otherwise normal respiratory function, would be so off the mark. Is there strong evidence to suggest this is the case?
Thank you!
Does "COTS" stand for "commercial off-the-shelf" or is this some more technical acronym related to CO2 measurements?
Ultimately the reason it's not popular is probably because it doesn't seem that useful. Breathing is automatic and regulated by blood CO2 concentration; I find it hard to believe that the majority of the population, with otherwise normal respiratory function, would be so off the mark. Is there strong evidence to suggest this is the case?
I agree that this wouldn't be useful for the majority of the population. (Some breathing gurus cl...
The $100 CO2 monitors do not measure CO2, they measure VOCs, which in typical home and office settings closely correlates with CO2 (because humans emit both at a relatively constant rate and humans are the main sources of both in typical home and office settings).
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Does this mean that a cheap "pseudo-capnometer" can be created which measures VOCs collected via a nasal cannula? Or would measuring VOCs instead of CO2 change the results at that level (but why?)?
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>Does this mean that a cheap "pseudo-capnometer" can be created which . . . ?
I doubt it, but don't know for sure because I don't know anything about the mechanisms by which people outgas the VOCs.
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There exist inexpensive real co2 sensors, e.g. https://www.sparkfun.com/products/22396 . Datasheet says only updates every 5 seconds & 60s response time "for achieving 63% of a respective step function", which I guess is what parent comment means by "They’ll likely be extremely slow".
Probably worth searching e.g. digikey for sensors with faster response time.
I was not familiar with that term, but I am aware of sleep apnea and how that can lead to too-high levels of carbon dioxide. Like I said in a different comment, my current understanding is that both too-high and too-low are problems. In my case (and in other cases where people have anxiety-like shortness of breath) I think what's going on is too-low carbon dioxide. But having a capnometer seems useful for correcting both too-low and too-high carbon dioxide.
My understanding is that like many things, both low and high are bad (high carbon dioxide is called hypercapnia), so you want to be in the "good" range (I typically see 35-45 mmHg of partial pressure carbon dioxide being cited as the good range). In rationalist circles I have seen discussion of too-high atmospheric carbon dioxide being bad, but I am myself confused on how that connects to carbon dioxide levels in the blood (and separately, I'm not convinced that higher carbon dioxide levels in the air are bad either).
I typically see 35-45 mmHg of partial pressure carbon dioxide being cited as the good range
That's about 5% (since atmospheric pressure is about 760 mmHg) or 50,000 ppm. Being in a room with that high a concentration of co2 is immediately dangerous to life and health, which is a good illustration of the fact that this post (your post) is about co2 in exhaled air, which is distinct from co2 in inhaled air or ambient air, where for example 5,000 ppm of co2 "is the permissible exposure limit for daily workplace exposures" (source).
Too much is bad, too little is bad, it has a number of important functions, so that poisonous bit is a huge oversimplification that gets repeated a lot, but is clearly incorrect if you need some to be alive.
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