8 ms·

Measuring blood pressure for less than a dollar using a phone

190 points by gumby 3y ago

nubinetwork 3y ago
I miss the SpO2 sensor on my old S5. It used to work up until a couple years ago when S Health took out the functionality.
- NikolaNovak 3y ago
  Oh Gawd. My wife did not feel well last year and thought her pulse was going up. I figure I'd reassure her quickly (or notice an issue) with my Note 8. Unbeknowst to me, some samsung update put the hardware functionality behind some health app that wanted to setup a tracking profile and two factor authentication and my email and my phone and name and details and preferences and goals and 12 point health plan and whatnot. By the end I was the one with anxiety attack. I'm still livid when I think about it. I'm not a violent or profane man but... I have some thoughts reserved for people who planned, approved and implemented that. Not all evil is big evil. Little evil is evil too (Note for all fellow software engineers here :)
  - lostlogin 3y ago
    If just for rate, surely a finger and a 15 or 30 second measurement is at least as good? Obviously you wont get oxygenation though.
    - NikolaNovak 3y ago
      I agree and that's what's my Note 8 used to provide. As I said, some update made the mandatory a health or whatever app require an account, 2fa, and a lot of setup and personal data before it'd let me access the sensor read.
      - notdang 3y ago
        previous comment meant to out the fingeron the wrist and count the pulse by yourself, analog way.
        spqr0a1 3y ago
        Surely the process of using fingers to measure discrete pulses is digital.
        sgtnoodle 3y ago
        I am pretty sure you're making a clever pun, but I would suggest the word "natural".
        NikolaNovak 3y ago
        Ah; yes I misinterpreted that thank you. Agree that would've done the trick for pulse :)
  - westurner 3y ago
    An open source app off Fdroid like HeartBeat may or may not have a similar error rate: https://github.com/berdosi/HeartBeat https://github.com/berdosi/HeartBeat I think I picked up a dedicated unit finger pulse oximeter for like $20. FWIU Apple Watch is one product with FDA approval as a medical device (ECG Electrocardiogram) for detection of AFib Atrial Fibrillation and Parkinsons. Medical device design > Pathway to clearance or approval: https://en.wikipedia.org/wiki/Medical_device_design#Pathway_to_clearance_or_approval https://en.wikipedia.org/wiki/Medical_device_design#Pathway_...
    - NikolaNovak 3y ago
      Thx for all the tips :) I did buy the separate $20 sp02 / pulse monitor after that episode. She has an apple watch now but I of course have zero confidence / will not trust the kindness of corporate strangers again to allow me access to my own hardware.
      - pkaye 3y ago
        Pulse oximeters will also give low spO2 if your fingertip is cold. In that case, just put your hand/fingers under your armpit for a few seconds to warm them up.
    - fibonachos 3y ago
      My Apple Watch detected an AFib about a year and a half ago. Was mildly freaked out at the time but glad that I got the alert. Nothing major, thankfully. Was on a mostly plant-based diet (no meat at all) and wasn't getting enough iron. Easy fix.
      - IndySun 3y ago
        >...Was on a mostly plant-based diet (no meat at all)... i.e., A vegetarian diet?
        JshWright 3y ago
        Sounds like it was vegetarian, bordering on vegan.
mhb 3y ago
Super clever. But one of the comments: This measures blood pressure in the fingers. There is no consistent way to translate that to a brachial artery blood pressure, which IS 'close enough' to the aortic valve. No calculations are needed, because the bloods pressure at the brachial artery will be only a few mm/Hg lower than it is at the aorta. But on the way to the fingers, the blood pressure lowers, and a multitude of factors can influence by how much. To be clear, all of the influences that alter the peripheral blood pressure will alter core blood pressure. But the degree of alteration is going to be far more extreme and unpredictable the farther away from the heart you go.
- devjab 3y ago
  The way ADHD medicine works in Denmark, I need to get my blood pressure measured at my doctors office every 3 months, and a while back when it was around the limit of being too high, they wanted me to do it at home for a period. So I asked if I could use one of these finger things, or even just a wrist thing and their answer was a clear no. Exactly because the number is essentially useless medically by our national guidelines. Sometimes our national guidelines are a little outdated. The ADHD medicine type that worked the best for me is still only approved for quitting smoking (which is why I don’t use it because that means it’s often out of stock since it’s not a “vital” medicine that gets priority stock”) but also goes to show that sometimes we’re a little slow to approve things. So I don’t know if these finger readers are in that category and will eventually become viable, or if they really don’t work. But I do think it’s worth looking into before you rely too much on them.
  - ktta 3y ago
    What's the name of the medication?
    - bladderlover23 3y ago
      Sounds like Bupropion.
    - mxmilkiib 3y ago
      In the UK, my psychiatrist has been taking my pressure every 6 weeks when I go back as I try to find an ADHD drug and dosage that works. This has been the case for all the stimulant type meds I've tried. I'm now finishing up my 6th week on the basic dose of atomoxetine, the first non-stimulant I've tried, and I'm guessing I'll not have my pressure tested later this week. I had off-book buproprion, not for ADHD but depression and anxiety, from the same psychiatrist from several months before they gave me an ADHD diagnosis, and didn't get my pressure tested then. Funnily enough I found that double the max UK dose (600mg/day, an accidental misreading of the dosage wording after a few months) worked perfectly with my so-called rejection sensitivity and hypermentalisation. Whether those symptoms were in some part generated by ADHD, it is possible, and whether my ASD or ADHD somehow gives me a buproprion hyposensitivity is questionable (as I have heard that ND folk can more often have a hyper and hypo sensitivity to drugs), but it didn't help my attention. I had to stop that when a) the manufacture of buproprion was halted due to detected impruties and b) so I could get to try ADHD meds. It made me very sad because I knew I would regress, I have indeed been emotionally unstable and prone to crises since and broke up with my partner in large part due to this.
westurner 3y ago
There are also low cost Smartphone fundoscopy devices for eye / retinal health chart images: https://www.aao.org/eyenet/article/smartphone-funduscopy https://www.aao.org/eyenet/article/smartphone-funduscopy You can't use AI to classify and predict e.g. diabetic retinopathy from retinal images unless you have retinal images in the chart, over time.
SoftTalker 3y ago
I’m not a doctor but my personal belief is that hypertension is over diagnosed. A lot of people have “white coat” syndrome, and pharma companies love to get people on never-ending prescriptions.
- car 3y ago
  I’m not a doctor but my personal belief is that hypertension is over diagnosed. A lot of people have “white coat” syndrome, and pharma companies love to get people on never-ending prescriptions. Thanks for letting us know that you are in fact not a doctor. Because your belief is patently wrong. Source: I am a doctor. https://baptisthealth.net/baptist-health-news/high-blood-pressure-commonly-underdiagnosed-but-easy-to-monitor-and-control https://baptisthealth.net/baptist-health-news/high-blood-pre...
  - voidfunc 3y ago
    I have high BP, I sort of see where OP is coming from... you need a lot of BP numbers to gain confidence about how bad the situation is. A one-off doctor visit once a year is not enough but it is often how the diagnosis is made. My best recommendation for people is to get a BP cuff and just get comfortable with taking samplings periodically through the day. I take anywhere from 3 to 10 readings a day and over a month or two the data paints a good picture of your situation plus it makes you more comfortable with BP reads.
    - pkaye 3y ago
      My MIL get white coat syndrome and every time she is at the hospital here numbers are much higher than at home. Her GP would not agree with this and continued to treat her with blood pressure pills aggressively. She would get dizzy and low pressure at home. Eventually switched to another doctor who trusted her and adjusted the prescription accordingly and those problems stopped and she managed to a reasonable BP range.
    - stinos 3y ago
      A one-off doctor visit once a year is not enough but it is often how the diagnosis is made Is that actually so? Around here, the very first thing which each doctor I know off is going to say after a high reading in such one-off visit is exactly your second paragraph, because they are well aware one-off readings cannot be trusted for a diagnosis and are typically higher because of white coat stress and whatnot.
ww520 3y ago
This actually is really cool. All the techniques are simple but combined together solve the problem very well.
JimtheCoder 3y ago
I'll get excited when someone comes up with a user friendly continuous blood pressure monitor. Until then...
- kekeblom 3y ago
  There is https://aktiia.com/uk/ https://aktiia.com/uk/
  - rlkf 3y ago
    The hardware seems nice, but to me it is a huge red flag that (1) the communication between the sensor and the phone is encrypted, so that no third-party app can ever be developed, and (2) it seems that your health data is uploaded to the "cloud" without any opt-out or possibility for local operation.
  - spyder 3y ago
    This looks like it' using the method that was mentioned in the article too, it needs regular calibration with a cuff (which they include with the product).
- moffkalast 3y ago
  One that doesn't violently strangle your arm/wrist would be a good start, even.
ck2 3y ago
Researchers discovered awhile back you can monitor blood pressure via the earlobes. Not only that, you can monitor it during activity during movement, without requirement to sit still. So I am really surprised some startup has not come up with a special earbud that also monitors blood pressure via a clip extension and broadcast via bluetooth/ANT+ Would be huge with athletes, especially with an aging population.
- smt88 3y ago
  The main issue would be the large and heavy battery
  - maven29 3y ago
    Integrate into wireless headsets? A single-purpose device could have most components on a neckband, otherwise.
AshamedCaptain 3y ago
This is not new at all. In the early 90s I had a Casio plastic watch that used a very similar method. http://digital-watch.com/DWL/1work/casio_bp-100/ http://digital-watch.com/DWL/1work/casio_bp-100/ A capacitive sensor to detect finger pressure and an optical one for the blood flow. Even cheaper than using a scale to detect pressure... The accuracy of course leaves a lot to be desired.
paxys 3y ago
Great tech no doubt, but it's funny that they tout a $1 attachment to a $500+ smartphone as being more accessible to low income people than a $20 standalone blood pressure monitor.
- mwint 3y ago
  Many low income people already prioritize having a phone over health(y/ier) food. And honestly, in today’s world that may not be as horrible a tradeoff as it first sounds.
  - midnightauro 3y ago
    Also you can finance a phone even with awful credit as long as the carrier you choose doesn’t have history with you. $45 a month for the top of the line iPhone is basically a fart in the wind at the grocery store.
collyw 3y ago
I bought a decent conventional blood pressure monitor for not very much money (20 or 30 euros from what I remember). Is doing it on a phone special?

190 points by gumby 3y ago

I miss the SpO2 sensor on my old S5. It used to work up until a couple years ago when S Health took out the functionality.

NikolaNovak 3y ago
Oh Gawd. My wife did not feel well last year and thought her pulse was going up. I figure I'd reassure her quickly (or notice an issue) with my Note 8. Unbeknowst to me, some samsung update put the hardware functionality behind some health app that wanted to setup a tracking profile and two factor authentication and my email and my phone and name and details and preferences and goals and 12 point health plan and whatnot. By the end I was the one with anxiety attack. I'm still livid when I think about it. I'm not a violent or profane man but... I have some thoughts reserved for people who planned, approved and implemented that. Not all evil is big evil. Little evil is evil too (Note for all fellow software engineers here :)
- lostlogin 3y ago
  If just for rate, surely a finger and a 15 or 30 second measurement is at least as good? Obviously you wont get oxygenation though.
  - NikolaNovak 3y ago
    I agree and that's what's my Note 8 used to provide. As I said, some update made the mandatory a health or whatever app require an account, 2fa, and a lot of setup and personal data before it'd let me access the sensor read.
    - notdang 3y ago
      previous comment meant to out the fingeron the wrist and count the pulse by yourself, analog way.
      - spqr0a1 3y ago
        Surely the process of using fingers to measure discrete pulses is digital.
        sgtnoodle 3y ago
        I am pretty sure you're making a clever pun, but I would suggest the word "natural".
      - NikolaNovak 3y ago
        Ah; yes I misinterpreted that thank you. Agree that would've done the trick for pulse :)
- westurner 3y ago
  An open source app off Fdroid like HeartBeat may or may not have a similar error rate: https://github.com/berdosi/HeartBeat https://github.com/berdosi/HeartBeat I think I picked up a dedicated unit finger pulse oximeter for like $20. FWIU Apple Watch is one product with FDA approval as a medical device (ECG Electrocardiogram) for detection of AFib Atrial Fibrillation and Parkinsons. Medical device design > Pathway to clearance or approval: https://en.wikipedia.org/wiki/Medical_device_design#Pathway_to_clearance_or_approval https://en.wikipedia.org/wiki/Medical_device_design#Pathway_...
  - NikolaNovak 3y ago
    Thx for all the tips :) I did buy the separate $20 sp02 / pulse monitor after that episode. She has an apple watch now but I of course have zero confidence / will not trust the kindness of corporate strangers again to allow me access to my own hardware.
    - pkaye 3y ago
      Pulse oximeters will also give low spO2 if your fingertip is cold. In that case, just put your hand/fingers under your armpit for a few seconds to warm them up.
  - fibonachos 3y ago
    My Apple Watch detected an AFib about a year and a half ago. Was mildly freaked out at the time but glad that I got the alert. Nothing major, thankfully. Was on a mostly plant-based diet (no meat at all) and wasn't getting enough iron. Easy fix.
    - IndySun 3y ago
      >...Was on a mostly plant-based diet (no meat at all)... i.e., A vegetarian diet?
      - JshWright 3y ago
        Sounds like it was vegetarian, bordering on vegan.

mhb 3y ago

Super clever. But one of the comments: This measures blood pressure in the fingers. There is no consistent way to translate that to a brachial artery blood pressure, which IS 'close enough' to the aortic valve. No calculations are needed, because the bloods pressure at the brachial artery will be only a few mm/Hg lower than it is at the aorta. But on the way to the fingers, the blood pressure lowers, and a multitude of factors can influence by how much. To be clear, all of the influences that alter the peripheral blood pressure will alter core blood pressure. But the degree of alteration is going to be far more extreme and unpredictable the farther away from the heart you go.

devjab 3y ago
The way ADHD medicine works in Denmark, I need to get my blood pressure measured at my doctors office every 3 months, and a while back when it was around the limit of being too high, they wanted me to do it at home for a period. So I asked if I could use one of these finger things, or even just a wrist thing and their answer was a clear no. Exactly because the number is essentially useless medically by our national guidelines. Sometimes our national guidelines are a little outdated. The ADHD medicine type that worked the best for me is still only approved for quitting smoking (which is why I don’t use it because that means it’s often out of stock since it’s not a “vital” medicine that gets priority stock”) but also goes to show that sometimes we’re a little slow to approve things. So I don’t know if these finger readers are in that category and will eventually become viable, or if they really don’t work. But I do think it’s worth looking into before you rely too much on them.
- ktta 3y ago
  What's the name of the medication?
  - bladderlover23 3y ago
    Sounds like Bupropion.
  - mxmilkiib 3y ago
    In the UK, my psychiatrist has been taking my pressure every 6 weeks when I go back as I try to find an ADHD drug and dosage that works. This has been the case for all the stimulant type meds I've tried. I'm now finishing up my 6th week on the basic dose of atomoxetine, the first non-stimulant I've tried, and I'm guessing I'll not have my pressure tested later this week. I had off-book buproprion, not for ADHD but depression and anxiety, from the same psychiatrist from several months before they gave me an ADHD diagnosis, and didn't get my pressure tested then. Funnily enough I found that double the max UK dose (600mg/day, an accidental misreading of the dosage wording after a few months) worked perfectly with my so-called rejection sensitivity and hypermentalisation. Whether those symptoms were in some part generated by ADHD, it is possible, and whether my ASD or ADHD somehow gives me a buproprion hyposensitivity is questionable (as I have heard that ND folk can more often have a hyper and hypo sensitivity to drugs), but it didn't help my attention. I had to stop that when a) the manufacture of buproprion was halted due to detected impruties and b) so I could get to try ADHD meds. It made me very sad because I knew I would regress, I have indeed been emotionally unstable and prone to crises since and broke up with my partner in large part due to this.

westurner 3y ago

There are also low cost Smartphone fundoscopy devices for eye / retinal health chart images: https://www.aao.org/eyenet/article/smartphone-funduscopy https://www.aao.org/eyenet/article/smartphone-funduscopy You can't use AI to classify and predict e.g. diabetic retinopathy from retinal images unless you have retinal images in the chart, over time.

SoftTalker 3y ago

I’m not a doctor but my personal belief is that hypertension is over diagnosed. A lot of people have “white coat” syndrome, and pharma companies love to get people on never-ending prescriptions.

car 3y ago
I’m not a doctor but my personal belief is that hypertension is over diagnosed. A lot of people have “white coat” syndrome, and pharma companies love to get people on never-ending prescriptions. Thanks for letting us know that you are in fact not a doctor. Because your belief is patently wrong. Source: I am a doctor. https://baptisthealth.net/baptist-health-news/high-blood-pressure-commonly-underdiagnosed-but-easy-to-monitor-and-control https://baptisthealth.net/baptist-health-news/high-blood-pre...
- voidfunc 3y ago
  I have high BP, I sort of see where OP is coming from... you need a lot of BP numbers to gain confidence about how bad the situation is. A one-off doctor visit once a year is not enough but it is often how the diagnosis is made. My best recommendation for people is to get a BP cuff and just get comfortable with taking samplings periodically through the day. I take anywhere from 3 to 10 readings a day and over a month or two the data paints a good picture of your situation plus it makes you more comfortable with BP reads.
  - pkaye 3y ago
    My MIL get white coat syndrome and every time she is at the hospital here numbers are much higher than at home. Her GP would not agree with this and continued to treat her with blood pressure pills aggressively. She would get dizzy and low pressure at home. Eventually switched to another doctor who trusted her and adjusted the prescription accordingly and those problems stopped and she managed to a reasonable BP range.
  - stinos 3y ago
    A one-off doctor visit once a year is not enough but it is often how the diagnosis is made Is that actually so? Around here, the very first thing which each doctor I know off is going to say after a high reading in such one-off visit is exactly your second paragraph, because they are well aware one-off readings cannot be trusted for a diagnosis and are typically higher because of white coat stress and whatnot.

ww520 3y ago

This actually is really cool. All the techniques are simple but combined together solve the problem very well.

JimtheCoder 3y ago

I'll get excited when someone comes up with a user friendly continuous blood pressure monitor. Until then...

kekeblom 3y ago
There is https://aktiia.com/uk/ https://aktiia.com/uk/
- rlkf 3y ago
  The hardware seems nice, but to me it is a huge red flag that (1) the communication between the sensor and the phone is encrypted, so that no third-party app can ever be developed, and (2) it seems that your health data is uploaded to the "cloud" without any opt-out or possibility for local operation.
- spyder 3y ago
  This looks like it' using the method that was mentioned in the article too, it needs regular calibration with a cuff (which they include with the product).
moffkalast 3y ago
One that doesn't violently strangle your arm/wrist would be a good start, even.

ck2 3y ago

Researchers discovered awhile back you can monitor blood pressure via the earlobes. Not only that, you can monitor it during activity during movement, without requirement to sit still. So I am really surprised some startup has not come up with a special earbud that also monitors blood pressure via a clip extension and broadcast via bluetooth/ANT+ Would be huge with athletes, especially with an aging population.

smt88 3y ago
The main issue would be the large and heavy battery
- maven29 3y ago
  Integrate into wireless headsets? A single-purpose device could have most components on a neckband, otherwise.

AshamedCaptain 3y ago

This is not new at all. In the early 90s I had a Casio plastic watch that used a very similar method. http://digital-watch.com/DWL/1work/casio_bp-100/ http://digital-watch.com/DWL/1work/casio_bp-100/ A capacitive sensor to detect finger pressure and an optical one for the blood flow. Even cheaper than using a scale to detect pressure... The accuracy of course leaves a lot to be desired.

paxys 3y ago

Great tech no doubt, but it's funny that they tout a $1 attachment to a $500+ smartphone as being more accessible to low income people than a $20 standalone blood pressure monitor.

mwint 3y ago
Many low income people already prioritize having a phone over health(y/ier) food. And honestly, in today’s world that may not be as horrible a tradeoff as it first sounds.
- midnightauro 3y ago
  Also you can finance a phone even with awful credit as long as the carrier you choose doesn’t have history with you. $45 a month for the top of the line iPhone is basically a fart in the wind at the grocery store.

collyw 3y ago

I bought a decent conventional blood pressure monitor for not very much money (20 or 30 euros from what I remember). Is doing it on a phone special?