Pulse oximeter

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vsc
With flying at higher altitudes I'm interested in buying a pulse oximeter for use onboard the plane. I'm interested in opinions on which type and perhaps brand.

Many years ago we purchased for a family member a "medical grade" Nonin pulse oximeter which used transmissivity on a fingertip. That said there are watch or watch like devices at this juncture that use reflectivity. The Nonin was as far as I can tell was very accurate and in fact transmissivity on a fingertip seems to be the gold standard for such devices.

That said in my reading there are mixed opinions on reflectivity based units (e.g. Garmin D2 Delta PX or exercise oriented devices) especially when one is unable to be motionless during measurement.

Perhaps getting another Nonin or a lower cost units is the best answer. But it would be nice to have one less thing kicking around the cockpit and have it combined with something that tells time.

Thoughts?
 
I have a cheap one from Amazon, serves the purpose and I have calibrated it a few times when I visit my physician. It’s pretty accurate. It’s kept along with a few other small item like PLB in small waist pack under the copilot seat. If I am high up, I will take it out before the flight and hang it on the copilot side and use it when required.
 
vsc said:
With flying at higher altitudes I'm interested in buying a pulse oximeter for use onboard the plane. I'm interested in opinions on which type and perhaps brand.

Many years ago we purchased for a family member a "medical grade" Nonin pulse oximeter which used transmissivity on a fingertip. That said there are watch or watch like devices at this juncture that use reflectivity. The Nonin was as far as I can tell was very accurate and in fact transmissivity on a fingertip seems to be the gold standard for such devices.

That said in my reading there are mixed opinions on reflectivity based units (e.g. Garmin D2 Delta PX or exercise oriented devices) especially when one is unable to be motionless during measurement.

Perhaps getting another Nonin or a lower cost units is the best answer. But it would be nice to have one less thing kicking around the cockpit and have it combined with something that tells time.

Thoughts?
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I don't know the Nonin brand, but there are many cheap transmissive units you can buy for under $20. Accuracy is not critical here, but trend is. At sea level it should show >98%. At altitude, do you really care if it shows 80% instead of 85%? They are both low, and you need oxygen asap. If you are concerned about reliability, buy two.
 
Walgreens, under $50. Or pharmacy depts at Walmart or Target. Almost impossible to find March - Oct 2020, but no problems now.

I had a medical grade ($300) many years ago, some kid destroyed it when I was teaching an intro aviation class at a local grade school. I asked the kid for his parents name and phone number, he shrugged, didn't care that he destroyed someone else's property. Never got the parents' info. Now, I don't care if anyone trashes the cheap one.
 
My cheap Walgreen’s units match what the ones at my doctor’s offices, which look pretty much like my cheapo version. My normal blood ox is 97%. What value do you use as the low threshold for supplemental oxygen?
 
Stewartb said:
What value do you use as the low threshold for supplemental oxygen?
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In the hospital we typically provide supplemental o2 for spo2 levels below 90%.
 
I have mine set for 92
 
Banggood and AliExpress have meters for under $10 that are accurate and have display of heartbeat.
 
I have a Nonin unit I bought years ago for about $300. My wife bought a cheap $35 pulse/oximeter from Amazon and the readings between both units are almost identical. Save your money and try a cheap unit.
 
I like to fly as close to 12500 as possible, especially in the summer when it is hot. It is great to fly at that altitude. Very comforting as well. I mean when I am at that altitude, it seams that nothing can go wrong! I don't need no stinking pulse-oximeter, I'm fine!
 
I had a few too many drinks this morning but I get what you’re saying.
 
GeorgeC said:
I flew home at 10500 recently and was surprised to see erratic readings below 90%; ended up descending to 8500.
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Don't be surprised. It is to be expected for those who reside at low altitude and have some pulmonary disease. It is normal for pulmonary function to decline with age so even if we are not aware we might not have the same function as we did when we were 20. There's a table in this article of what levels are expected at various altitudes:
https://thorax.bmj.com/content/thoraxjnl/early/2017/10/20/thoraxjnl-2017-210598.full.pdf
 
What finally pushed me to start using the oxygen is all the damage done to my right leg since our accident in 2018. I started to notice that if I flew from 6.5 and up I would have pain in my ankle, shin and knee area for a few days after flying. My sister-in-law, the nurse, did some research and thought it would be a pressurization or oxygen problem. Well, I could fix one of those issues so I mounted the bottle. After crossing the Delaware Bay at 7.5 and returning at 6.5 I have to say I had no pain following my flight. I also followed my brides advice and finally wore a compression sock on the right leg.

My pulse ox numbers at 7.5 without the oxy hook up 91. With the hook up and pita cannulas 96. I guess I'll keep the tank in the plane and use when above 6.5 for now on. Gettin' old ain't for sissies....and this beat up body needs all the help it can get.

tank set up and before use shot of pulse ox

oxygen tank set up.jpg pulse ox before.jpg
 
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3 years ago I bought the "oxywatch pulse oximeter by choicemmed" for about $32 and very happy with it.
(I needed it for medical reasons unrelated to aviation)

Amazingly accurate ... I test it against the hospital version when I am there ..... always exactly the same reading .... user friendly and works quickly .... only takes about 15 seconds to give oxygen level reading ..... it uses 2 AAA batteries that lasted me two years (I use it about 6 times a day) ..... have inadvertently dropped it several times and did not harm it ... no special instructions other than finger should be reasonably clean and warm (will not work on cold hands)

Oxygen trivia: .... normal levels should be 95% to 100% ..... occasionally mine was 92% and considered low ... anything below 90% considered dangerously low .... 2-3 minutes on supplemental oxygen and my levels go up to 98-99% ... oximeter gives results instantly.

oxywatch pulse monitor.JPG
 
A pulse ox is fascinating. I was cruising at 12k a week or two ago and put mine on. My 02 sat was 98%, so I was happy about that, but I was surprised to see my heart rate at 107. I didn't feel stressed or nervous...I assume that was my CV system compensating for the thin air.
 
I’m either super human or close to death. Not sure which? My 02 sat is 94 ish at sea level and pretty much the same at 8-10 k. My wife’s O2 drops pretty fast at 10k 91-92 and she feels wiped out after a couple hours. I keep looking at oxygen generators, just trying to understand if they actually work. I would definitely buy one instead trying to keep O2 bottles full. I just can’t seem to find anything concrete saying oxygen generators work at altitude.
 
AlphaMike said:
I’m either super human or close to death. Not sure which? My 02 sat is 94 ish at sea level and pretty much the same at 8-10 k. My wife’s O2 drops pretty fast at 10k 91-92 and she feels wiped out after a couple hours. I keep looking at oxygen generators, just trying to understand if they actually work. I would definitely buy one instead trying to keep O2 bottles full. I just can’t seem to find anything concrete saying oxygen generators work at altitude.
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I also have an in-home oxygen generator .... plugs into 110 outlet and can produce a high rate of oxygen (up to 6 liters per minute). (usually only 2-3 litres are required)

I am aware of other more portable generators (backpacks etc) but I don't know if they work on the same principle. Mine is an electrical motor driving a pump of some sort which separates oxygen from surrounding air.

But your actual question was ..... "will it work at altitude" ... I would guess yes .... but at a reduced volume because there is less oxygen in the surrounding atmosphere.

.
 
This thread got me to buy one on prime day. Spent all of $12 and it seems to work just fine. It's part of the flight bag now. Thanks guys!
 
AlphaMike said:
I’m either super human or close to death. Not sure which? My 02 sat is 94 ish at sea level and pretty much the same at 8-10 k. My wife’s O2 drops pretty fast at 10k 91-92 and she feels wiped out after a couple hours. I keep looking at oxygen generators, just trying to understand if they actually work. I would definitely buy one instead trying to keep O2 bottles full. I just can’t seem to find anything concrete saying oxygen generators work at altitude.
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Ever smoke? As a firefighter responder, it's not uncommon to see people in the 90-95% range, and usually doesn't indicate much to worry about. We may still administer O2 as it can't hurt and makes the patient feel like we are doing something to help. 9 out of 10 medical calls we run usually just need to get to the hospital for further diagnosis. Not much we can do in the field.
 
midwestpa24 said:
Ever smoke? As a firefighter responder, it's not uncommon to see people in the 90-95% range, and usually doesn't indicate much to worry about. We may still administer O2 as it can't hurt and makes the patient feel like we are doing something to help. 9 out of 10 medical calls we run usually just need to get to the hospital for further diagnosis. Not much we can do in the field.
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It might not seem to hurt that smoker when they are sitting on a bench smoking a cig, but when was the last time you saw a smoker running a 5k and doing well? As you have probably seen over the past year, we humans can survive O2 levels down into the 70's and 80's with Covid, but it puts the body at the point where the littlest stress can cause complete collapse. I bet that those smokers bodies would react quite differently to 10k altitude than a non-smoker (both within standard deviations and large sample sizes). You know this already, just pointing out that 90% may be OK one minute and totally not OK the next minute from one person to another from situation to situation.
 
midwestpa24 said:
Ever smoke? As a firefighter responder, it's not uncommon to see people in the 90-95% range, and usually doesn't indicate much to worry about. We may still administer O2 as it can't hurt and makes the patient feel like we are doing something to help. 9 out of 10 medical calls we run usually just need to get to the hospital for further diagnosis. Not much we can do in the field.
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I tried smoking when I was in my 20s but never for any length of time. I do chew tobacco though (keep trying to quit!). I don't think that affects the lungs like smoking does.
 
I rarely get to fly that high, so O2 and an oximeter haven't been much on my radar. If I ever get to do the IR thing they'll go up on the list. I have to admit, I get pretty fatigued after a long day at high altitude.
 
Slight thread drift. I recently got a CO detector for the plane. With this hot WX the other day I was taxiing the archer with the door open. The detector started to sing at 35 ppm. Just blowback, once I took to the sky it went back to 0. But I learned two things, apparently I was gassing myself during the taxi and a CO detector is a good thing! Oh yeah, I also have a pulse oximeter :)
 
I have a several-year-old recording pulse oximeter. This is great because it can store several hours of pulse and O2 Saturation data. Unfortunately, it's old enough that it won't work with Windows 10 machines. I really like the ability to log the data - it was terrific for getting good baselines when I was starting to do higher cross-country flights and mountain flying. It's also great for tracking sleep overnight when camping at 10K feet, or doing a long commercial flight.

Anyone know of affordable recording pulse oximeters that work with Windows 10 and forwards? Thanks.
 
Joe_B1 said:
Slight thread drift. I recently got a CO detector for the plane. With this hot WX the other day I was taxiing the archer with the door open. The detector started to sing at 35 ppm. Just blowback, once I took to the sky it went back to 0. But I learned two things, apparently I was gassing myself during the taxi and a CO detector is a good thing! Oh yeah, I also have a pulse oximeter :)
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Just note that a pulse oximeter will not indicate CO poisoning. Most pulse-ox will still detect the O in CO, and will show normal o2 percentages even though the CO is displacing the o2 in your blood. We do have some fancy high-tech (spendy) units on our ambulances that can differentiate and indicate o2 as well as CO in the blood, but I doubt the average Joe wants to spend that kind of dough.
 
Latest version of the Apple Watch (v6+) has it included, checked with the dr last time I was there and it was within 1% of his. So...ymmv.
 
BryanAV8R said:
Latest version of the Apple Watch (v6+) has it included, checked with the dr last time I was there and it was within 1% of his. So...ymmv.
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I can’t get the watch to read in my plane. Always complains that I’m moving.
 
AlphaMike said:
I just can’t seem to find anything concrete saying oxygen generators work at altitude.
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A relative living at 5000’ altitude used one at home, with a cannula, for cancer. Powered by 110 V. Met her needs.

Have you looked for manufacturer specs?
 
Jim K said:
A pulse ox is fascinating. I was cruising at 12k a week or two ago and put mine on. My 02 sat was 98%, so I was happy about that, but I was surprised to see my heart rate at 107. I didn't feel stressed or nervous...I assume that was my CV system compensating for the thin air.
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It seems pretty implausible your %sat was truly 98 at 12K. You may want to try another one - maybe borrow one from a friend or something and compare them. The fact that your heart rate was 107 (assuming that’s not your normal resting rate) supports this.
 
During the pandemic, I finally got around to trying out the oximeter that I bought years ago. I found that it was too dim to be read in a GA airplane in daylight, which was ironic given that I bought it from a pilot supply place. Since then it has gotten worse, to the point where now it's hard to read even in the dark, so it may have deteriorated from sitting around. I recently replaced it with one that has a passive liquid crystal display, so that it doesn't have the problem of internal illumination trying to compete with sunlight.

It claims 2% accuracy and agrees with the previous one. I also verified that it responds to changes in O2 by observing the drop in readings when I hold my breath.
 
I just saw a Facebook ad for a pulse oximeter for $299. It looks just like my $29 unit from Walgreens. But at 10x the price? It MUST be better, right? ;)
 
Our Dr. office has this one, I found the same model on Amazon and grabbed it:
Contec
https://www.amazon.com/CONTEC-Oximeter-Fingertip-Saturation-Batteries/dp/B08CN6ZT1K

I tested it at 11K ft. My CFI and I sat ranged from 98 to 86%. It responded appropriately to various maneuvers such as breath hold, shallow breathing, deep breathing. The data also correlated well with feeling the effects of hypoxemia and its resolution with corrective action (my CFI got pretty fuzzy at one point !! :p ). I am very confident that it is accurate.

As far as what the numbers mean, hemoglobin absorbs oxygen in a nonlinear fashion, so the oxygen saturation you see on the pulse ox does not correlate linearly with the amount of oxygen in your blood. It is actually a sigmoid shaped curve. Google "oxyhemoglobin dissociation curve" and you can find a picture. In particular, it is worth knowing that the amount of oxygen carried by the blood has pretty minmal change between 88% and 100% saturation. At 88% saturation on the pulse ox, you get to that break in the curve where the amount of oxygen in the blood drops rapidly. It then follows that any number you see below 88% should be acted on immediately and may cause hypoxic effects. Above 88, there's no predicting how you will feel. As the flying manual states, you may be affected or not depending on your physiology that day. If you have any underlying health issues, such as coronary blockages, levels between 100-88 may certainly cause symptoms as well. There was a story in Flying Magazine, I think, that mentioned a pilot attempting to cross the Rocky Mountains and his passanger without oxygen developed angina with altitude, which was likely due to mild hypoxemia that a healthy man would likely not be affected by.

It is also worth noting, and you can check this out for yourself, if you breathe some deep breaths, you can bring your sat up pretty easily if your on the margin. So if your at altitude and feeling fuzzy, a few deep breaths can clear your head. There are other considerations, in this situation, so if this should happen, you should drop your altitude or put on oxygen. Deep breathing for an extended time is hazardous, as you will end up getting hypocarbic which can cause you to pass out.

And my disclaimer! The above is not medical or piloting advice. Hypoxemia is a life threatening situation that should be corrected immediately. Please follow all FAA rules and regulations.
 
I have a large cylinder in my hangar and made a transfill setup to keep my "D" bottle filled using O2 anytime above 8000 for more than 30 minutes. As I get older, even mild hypoxia affects me in thought, reaction and fatigue. I use the Mountain high nasal cannula that attaches to my headset and flips down when I need it. More comfortable than standard cannulas. At night, oxygen anytime above 5000 as color vision is the first to go. I've tried multiple oximeters and all are close enough to be effective as a guide to your oxygenation status. I also use a small CO detector that works nicely, https://www.amazon.com/gp/product/B076S6KBP2/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1
Just my personal thoughts....and 30 years of medical practice in pulmonary and critical care :)
 
Kaweeka said:
I have a large cylinder in my hangar and made a transfill setup to keep my "D" bottle filled using O2 anytime above 8000 for more than 30 minutes.
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That can be a great solution.

For those not familiar with handling high pressure O2, there are pitfalls that aren't necessarily obvious, and things can go very badly, very fast. Become familiar with the safety protocols before attempting this.
I recommend the Oxygen Hacker's Companion as one good resource. http://www.airspeedpress.com/newoxyhacker.html It is written more for tech divers, who do gas blending with O2, but it covers what you need to know to safely transfill oxygen.
 
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