The Royal Melbourne hospital in Australia is using pulse oximeters to manage COVID positive patients in their own homes. The program was setup in March this year to manage a large number of patients remotely (cost/safety).
The patients take their own measurements with a pulse oximeter and digital thermometer (both off the shelf consumer items). The person is prompted via SMS and submit their vitals via website. A software system orchestrates all of this and alerts patients and clinicians to anyone with worrying numbers.
This keeps beds free at the hospital, but still gets the small percentage of patients back to hospital that get really sick.
It also does all the other boring monitoring and administrative work needed when you're checking up on lots of real people.
Full disclosure. I worked on this project. A version has been open sourced and if you're a hospital or other medical service you're welcome to use our work. We're publishing improvements as we go.
https://github.com/rmhcovid/txtmon
Using simple standalone devices and a low-coding platform already in use by hospitals (REDCap) the whole project was crash-built in a couple of weeks and is saving lives. That platform has many shortcomings (messier even than Excel), but there's various medical/privacy rules that make more traditional development unattractive for quickly prototyping. It's been a rewarding project to work on despite many frustrations.
Thank you for sharing this. In the program guide it says a temperature reading of > 42 degrees or an oxygen saturation of < 90 are the thresholds for a MET call. Is there a basis for these specific values or are they general approximations?
Off-topic, but an inventor of the Pulse Oximeter recently passed away [1]:
"Takuo Aoyagi, a Japanese engineer whose pioneering work in the 1970s led to the modern pulse oximeter, a lifesaving device that clips on a finger and shows the level of oxygen in the blood and that has become a critical tool in the fight against the novel coronavirus, died on April 18 in Tokyo. He was 84."
I measured myself at home in Mexico City and got 93%. I got kind of worried, knowing people sick with COVID-19 can have very low saturation levels without realising it. Then I remembered I was standing at about 2200 m above sea level. Lots of unexpected weirdness happens at high altutude
I’ll be honest, a lot if the portable oxygen saturation monitors seem to report slightly out of range readings. It often picks up after a few minutes, I suspect they are calibrated poorly tbh.
94-98% is the desired range.
At the time they reported that there were mentions of it in an iOS 14 leak, but it wasn't clear if it would be a software update to existing watches (somehow able to detect it with existing heartrate hardware) or in a watch hardware revision. Since it wasn't mentioned in the watchOS news at WWDC, looks like it'll be new hardware.
Either that or the code they found in iOS 14 was related to the health app and support for 3rd party oximiters, but that's not how the 9to5 post frames it so best I can do is take their word for it.
Does anyone know, in general, if a watch device already has a pulse measurement LED system, whether that can also serve as a pulse ox measurement? or are they different hardware requirements?
The problem with pulse oximeters is the people who need them often can't use them. Yes I know it's not meant as a medical device.
My dad has COPD and IPF but he can't use the SPO2 meter on the Samsung phone I gave him (and Samsung disabled the SPO2 function for Canada). A Garmin VivoSmart 4 can't give a decent reading on him or me and it takes forever. Part of the problem is blood flow dad's fingers are ice cold due to his condition.
My dad uses a cheap oximeter from Walmart it works better than anything else. It's the type that clips over a finger it's fast and seems to be accurate. I'd like to get a wristband or watch that has a good SPO2 meter but nothing seems to exist.
The most painful thing I've experienced medically was an arterial blood draw to measure my o2 sat levels. (They numb your inner wrist with novocaine then go in with a giant needle to the artery deep in there. If it's that painful numb, I can't imagine what it'd be like otherwise.
And each time it was no more accurate than the pulse oximeter.
Went to a party last weekend where the host used a pulse oximeter (and thermometer) on everyone. Blood O2 level is apparently a leading indicator of COVID-19. Pretty cool stuff. The inner workings of it are actually quite simple as well, pretty amazing that it works as well as it does.
It’s probably a leading indicator of COVID pneumonia but that probably still takes some days to develop during which time infected people are still contagious. Probably better to stay home or at least wear a mask...
Pulse oximeters are not all that simple. The general idea is easy enough to get across and it's possible to build a fairly simple one that will work some of the time. But the top end, highly reliable ones that work well at low sats are pretty complicated things.
It's always interesting to me how much of a hivemind the internet has and how many coincidences there are. Just last night I dug out my cheapo pulse oximeter and checked everyone in my house to get a baseline.
I then googled how they work and read pretty much the same thing.
Does anybody have any suggestions for how to check whether a pulse oximeter actually works properly?
I bought one online from a not particularly trustworthy shop. I have never seen it show any value other than 99%. How can I figure out whether it actually does anything and doesn't just show 99% no matter what?
I purchased a relatively cheap one from Amazon a couple of months ago. Less than $50, I believe.
I tried some simple stuff when it arrived. I believe I was able to get it to swing within the 94-99% range by holding my breath and by deliberate, deep breathing, over the span of just a minute or two. It definitely was not pegged at 99%. The changes were surprisingly fast. My wife was able to get the same response.
If it matters, I'm at about 500 feet above sea level (not high-altitude at all).
I have a cheap one so I am not sure if the absolute values are correct. But they change very reliably and consistently. With breathing exercises I can take the value from the usual 95-97 to 99. When I hold my breath long enough I can take the value down to 75 or less.
There is a delay of 20-30 seconds between changing my breathing to the oximeter changing its value. I suppose this is how long it takes for the blood to get around in the body.
To test it's accuracy or just to see if it ever shifts from 99% (or random fluctuations)? For the latter you you'd just use inorganic material of varying thickness/opaqueness.
I have CF, so I regularly check my o2 sat levels. I actually used mine the same day as I had a checkup; I recall it being spot on. (Homedics model from Walgreens I think)
SO is an internal medicine doctor. When covid was ramping up at first and we thought there would be beds in school gyms and stuff the first thing she did was get a pulse oximeter off the internet.
FWIW some Samsung phones (and probably others) have this functionality built in. I've tested mine and I consistently get readings within 1 point of my gold-standard Nonin pulse oximeter.
Was going to send this link, but alas you already did. Alec is so good at this and I'm a proud Patron of his work. It's always really well done and thoughtful.
Does anyone know the degradation in blood oxygen levels under moderate exercise for a person who is fairly health (not athlete but slim, does regular exercise)?
I had covid, so bought one of these, and I'm now building my way back to being able to jog, after months of shortness of breath. I would like to be able to understand what level my blood oxygen %, for a normal, healthy person, would drop to when say jogging.
If I really push during my 5k run, pulse oxymeter shows around 85%. Not sure how much to trust it, as soon as I stop it climbs back up. Unclear if it's due to vibrations, or my lungs catching up.
It’s weird, when I have a pulse oximeter on my finger and a blood pressure cuff on and it’s rather inflated I get electrical feeling shocks up my arm. The both have to be on the same arm. No idea what it is, probably a pinched nerve.
It is really grating that all the visualizations are wrong. Blue is shorter wavelength than red. Infrared is longer wavelength than red. Every single image is wrong. :(
One is a red light, which has a wavelength of approximately 650 nm. The other is an infrared light, which has a wavelength of 950 nm. (Throughout our description, we will show the infrared light in light blue. In reality, infrared light is invisible to the human eye.)
The blue color is being used for infrared so the wavelength is right. The author could have used a '-- red' for infrared rather than blue to be less confusing.
[+] [-] maxfan8|5 years ago|reply
(for those who can't access the original site due to it being hugged to death)
[+] [-] danieltrembath|5 years ago|reply
The patients take their own measurements with a pulse oximeter and digital thermometer (both off the shelf consumer items). The person is prompted via SMS and submit their vitals via website. A software system orchestrates all of this and alerts patients and clinicians to anyone with worrying numbers.
This keeps beds free at the hospital, but still gets the small percentage of patients back to hospital that get really sick.
It also does all the other boring monitoring and administrative work needed when you're checking up on lots of real people.
Full disclosure. I worked on this project. A version has been open sourced and if you're a hospital or other medical service you're welcome to use our work. We're publishing improvements as we go. https://github.com/rmhcovid/txtmon
https://www.thermh.org.au/news/royal-melbourne-hospital-impl...
Using simple standalone devices and a low-coding platform already in use by hospitals (REDCap) the whole project was crash-built in a couple of weeks and is saving lives. That platform has many shortcomings (messier even than Excel), but there's various medical/privacy rules that make more traditional development unattractive for quickly prototyping. It's been a rewarding project to work on despite many frustrations.
[+] [-] elif|5 years ago|reply
[+] [-] sohkamyung|5 years ago|reply
"Takuo Aoyagi, a Japanese engineer whose pioneering work in the 1970s led to the modern pulse oximeter, a lifesaving device that clips on a finger and shows the level of oxygen in the blood and that has become a critical tool in the fight against the novel coronavirus, died on April 18 in Tokyo. He was 84."
[1] https://www.nytimes.com/2020/05/01/science/takuo-aoyagi-an-i...
[+] [-] Fabricio20|5 years ago|reply
[0]: https://www.youtube.com/watch?v=4pZZ5AEEmek
[+] [-] ravedave5|5 years ago|reply
[+] [-] linsomniac|5 years ago|reply
[+] [-] ornel|5 years ago|reply
[+] [-] Engineering-MD|5 years ago|reply
[+] [-] amelius|5 years ago|reply
[+] [-] wlesieutre|5 years ago|reply
https://9to5mac.com/2020/03/08/apple-watch-blood-oxygen-satu...
At the time they reported that there were mentions of it in an iOS 14 leak, but it wasn't clear if it would be a software update to existing watches (somehow able to detect it with existing heartrate hardware) or in a watch hardware revision. Since it wasn't mentioned in the watchOS news at WWDC, looks like it'll be new hardware.
Either that or the code they found in iOS 14 was related to the health app and support for 3rd party oximiters, but that's not how the 9to5 post frames it so best I can do is take their word for it.
[+] [-] deadmutex|5 years ago|reply
https://www.wearable-technologies.com/2020/01/fitbit-adds-bl...
[+] [-] supernova87a|5 years ago|reply
[+] [-] bdcravens|5 years ago|reply
[+] [-] dghughes|5 years ago|reply
My dad has COPD and IPF but he can't use the SPO2 meter on the Samsung phone I gave him (and Samsung disabled the SPO2 function for Canada). A Garmin VivoSmart 4 can't give a decent reading on him or me and it takes forever. Part of the problem is blood flow dad's fingers are ice cold due to his condition.
My dad uses a cheap oximeter from Walmart it works better than anything else. It's the type that clips over a finger it's fast and seems to be accurate. I'd like to get a wristband or watch that has a good SPO2 meter but nothing seems to exist.
[+] [-] bdcravens|5 years ago|reply
And each time it was no more accurate than the pulse oximeter.
[+] [-] dvt|5 years ago|reply
[+] [-] joshgel|5 years ago|reply
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[+] [-] bestnameever|5 years ago|reply
[+] [-] leetrout|5 years ago|reply
I then googled how they work and read pretty much the same thing.
[+] [-] DangerousPie|5 years ago|reply
I bought one online from a not particularly trustworthy shop. I have never seen it show any value other than 99%. How can I figure out whether it actually does anything and doesn't just show 99% no matter what?
[+] [-] mturmon|5 years ago|reply
I tried some simple stuff when it arrived. I believe I was able to get it to swing within the 94-99% range by holding my breath and by deliberate, deep breathing, over the span of just a minute or two. It definitely was not pegged at 99%. The changes were surprisingly fast. My wife was able to get the same response.
If it matters, I'm at about 500 feet above sea level (not high-altitude at all).
[+] [-] deadmutex|5 years ago|reply
[+] [-] spaetzleesser|5 years ago|reply
There is a delay of 20-30 seconds between changing my breathing to the oximeter changing its value. I suppose this is how long it takes for the blood to get around in the body.
[+] [-] renewiltord|5 years ago|reply
It is hard to do so normally so I forced the air out and then pinched my nose shut with my fingers to prevent accidentally breathing in.
[+] [-] OJFord|5 years ago|reply
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[+] [-] amiga_500|5 years ago|reply
I had covid, so bought one of these, and I'm now building my way back to being able to jog, after months of shortness of breath. I would like to be able to understand what level my blood oxygen %, for a normal, healthy person, would drop to when say jogging.
[+] [-] pps43|5 years ago|reply
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[+] [-] bookofjoe|5 years ago|reply
[+] [-] bookofjoe|5 years ago|reply
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[+] [-] alister|5 years ago|reply
One is a red light, which has a wavelength of approximately 650 nm. The other is an infrared light, which has a wavelength of 950 nm. (Throughout our description, we will show the infrared light in light blue. In reality, infrared light is invisible to the human eye.)
[+] [-] hakcermani|5 years ago|reply
[+] [-] vwcx|5 years ago|reply