8 ms·

The science behind on-the-wrist blood pressure tracking

156 points by brandonb 2y ago

bloopernova 2y ago
Tangentially Related: https://arstechnica.com/health/2024/10/your-doctors-office-could-be-reading-your-blood-pressure-all-wrong/ https://arstechnica.com/health/2024/10/your-doctors-office-c...
- brandonb 2y ago
  Yeah -- in addition to inappropriate measurement technique, "white coat hypertension" can cause elevated blood pressure readings. And, of course, you have the fact that the American College of Cardiology (ACC) updated their blood pressure guidelines in 2017 to use a lower threshold. So some people with moderately high blood pressure would now be considered to have hypertension and are recommended to seek treatment.
  - user3939382 2y ago
    The threshold was 160. Then 140, then in 2017 130 so suddenly millions of new people whom were fine the day before now have a hypertensive crisis and need to be prescribed pharmaceuticals for the rest of their lives. The profit arising from this change is just a happy coincidence arising from the evidence.
kbrisso 2y ago
Measuring blood pressure on the wrist is tricky. I usually do three measurements to get an accurate reading. I have two machines I use. The older one is actually better than the new one. Another thing is, pay attention to how you feel. I can feel my blood pressure when it's high and usually know when the device reading is off. I do this because my family has a history of high blood pressure and so far because of lifestyle choices I have avoided the need for meds.
- wil421 2y ago
  Why do you have to do it so often? Why do you even do it if you’re not on meds? Third, what would you even do if it’s high?
  - kbrisso 2y ago
    I don't check my blood pressure every day. Maybe twice a month or when I feel like crap. I also check my glucose. Why? I believe if I keep myself in check I will keep myself out of the hospital as I age. High blood pressure and diabetes are two things I can manage. I don't want to be on meds unless I absolutely have to. Exercise and these tools allow me to figure out what I can eat and not. I'm not obsessed with my health or a health "nut". The upside is I don't get sick that much and feel good.
- j_bum 2y ago
  What are some examples of the non-pharmacological/lifestyle approaches you’ve taken?
corry 2y ago
Actually, there is a wrist device called "Aktiia" that's approved for use for continuous BP monitoring with clinical accuracy by the UK and German health authorities (I believe). It's a bit of a pain to get over the pond, but with a shipment-forwarding company + a UK App Store account you can get up and running. I've dabbled a bit with it and it's very close to the cuff measurements. It works by calibrating with their custom arm cuff device. I'd guess that it's correlating what the wrist sensor sees w.r.t. your wrist blood vessels and what the "true" reading is from your arm. You re-do the calibration every few weeks. The device takes a reading every 20 or 30 minutes or so and seems to try to pick periods where you're more stationary. However, one thing to be aware of is that you are not used to seeing your BP readings from the entire day. Did you jump in a cold plunge 10 minutes before it ran? Get ready to see a really high reading dot in the 'danger zone'. Went for a jog and are catching your breath on a park bench? High dot. This isn't a bad thing, it just takes some getting used to since your "daily average" will be significantly above the readings you're used to if you're doing arm cuff measurements at the start/end of the day. Of course it's also getting readings at those more usual times too, but they get washed out in the larger number of data points from your day. And goes without saying, your blood pressure SHOULD go up and down based on your activity and time of day. You just aren't used to seeing it other than at true rest. But all in all it's been fascinating to see, and there's no doubt in my mind that this technology will be mainstream quickly (and Apple will likely dominate it).
- Etheryte 2y ago
  This is super exciting, thanks for posting! I developed high blood pressure after Covid and have done a few 24h studies to better understand it. The traditional machines are super bulky, essentially like carrying a regular BP monitor around with a pouch that's strapped to you, maybe just a bit smaller. All in all it's far from convenient and can kick in at inopportune times. Having around the clock insights would hopefully give me a better understanding of the condition. For context, I've jumped through all sorts of specialty doctor hoops and there is no known underlying cause outside of the fact that it just showed up after Covid. Do you or anyone you know happen to have firsthand experience with the device?
  - 2y ago
oidar 2y ago
I would love to have continuous BP monitoring. I ready for this tech to mature. I'd wager that blood pressure varies way more during the day than weight (which can vary as much as 5 lbs or more) - and continuous, easy BP monitoring at would cause HT dxs to drop significantly.
- candiddevmike 2y ago
  Why do you think this would cause HT diagnosis to drop? If anything all of these continuous monitors create more patient visits and probably more diagnosis. I'm interested in what the future holds when these things are capable of FDA-approved diagnosing. Will Apple send a prescription for BP meds to my pharmacy?
  - oidar 2y ago
    I think there is a lot of white coat HT that makes up many cases. I think the ACS recommends a measurement 3 times in a row at different office visits. So, maybe anxiety might be a direct cause of HT dx.
- rootusrootus 2y ago
  > HT dxs I'm unfamiliar with this abbreviation but did my best with Google. Does it mean 'hypertension diagnoses'?
  - oidar 2y ago
    yes
- wil421 2y ago
  The problem with this is exercise messes with blood pressure. “Extremely high blood pressure elevations of up to 345/245 mmHg were observed during the lifts.”[1] My doc even said it can get as high as 400 and it’s important to breathe correctly. [1]https://pubmed.ncbi.nlm.nih.gov/2632751/ https://pubmed.ncbi.nlm.nih.gov/2632751/
  - 2y ago
stewh_eng 2y ago
I'm a med device engineer and have watched the hopes and dreams of cuffless BP monitoring tech. I hope we get there as it will be hugely important. However, remember tech is only a small part of the battle. We need to figure out clinically what to do with all this new continuous data. I am very sceptical PPG alone will be capable for many reasons. Aktiia does indeed have European regs clearance. But, they don't have FDA clearance. The FDA is a very different beast (more hands on - and they'll be absolutely much more heavy with such a new approach) - and they must have concerns on the approach for it to take this long. The FDA even has accelerated programmes for breakthrough high impact tech as they really do want it to get to market safely. The main cuffless FDA cleared devices I know measure the pulse transit time betwen a central ECG patch and a peripheral based PPG (that time is then calibrated to a BP with the Moens Kourteweg equation) - see Biobeats watch and a now defunct wearable ICU monitor company I can't find the name of. The issue with PPG is that it is wildly sensitive. The PPG waveform morphology will changed dramatically based on the pressure of the sensor against the skin, unconstrained changes in orientation of the human and arm etc. Changes in morphology != changes in system wide BP. Speak to an anaesthesiologist and they'll tell you blood pressure is function many things eg cardiac output, stroke volume, heart rate, blood volume, total peripheral resistance etc etc (https://www.sharinginhealth.ca/multimedia/images/blood_pressure.jpg https://www.sharinginhealth.ca/multimedia/images/blood_press...). The question is whether PPG alone can measure all these things. I suspect it's really just measuring lots of proxies of all these things. And that's fine - however in the presence of people with conditions or on therapeutics that alter these in very personalised and unpredictable ways then error may start to creep in on free living measurement. Paradoxically, it's probably these people for whom this tech would have most impact - not the worried well.
- utschig 2y ago
  Sotera Wireless
  - stewh_eng 2y ago
    That's the one! They were lightyears ahead but seemingly couldn't make the commercials work. Thank you!
gausswho 2y ago
I am fascinated by the concept of blood pressure as one of the foremost tools of health. Can someone recommend perhaps a book size read on the history of how we came to learn of its value and help illuminate well... what it even is?
jcims 2y ago
Side note, I started monitoring with a cuff-style monitor over the past month, and one thing that’s super important is keeping the cuff at about heart level. The cuff I got actually reminds you of this verbally. While it obviously makes sense, it’s a bit surprising how much a change in elevation affects the readings.
- isoprophlex 2y ago
  Try sticking it around your ankle and measuring while standing up. I get 250 mmHg systolic, easily
daemonk 2y ago
For most instruments, it's an interplay between resolution and consistency. There isn't a "true" reading in any sense of the word. There is just how much resolution you are measuring and how consistent the measurement is between independent readings of the same event. The overwhelming amount of pre-existing clinical data gathered by cuff-monitors means that any novel measurement methods benefit from tying/correlating their output to the existing data for compatibility. It's a bit unfortunate in some sense as cuff-monitor data lacks resolution and sometimes can be a bit of a drag on novelty.
mysterypie 2y ago
I'm hoping someone can answer a question that's been bugging me for years: When I take blood pressure medication my blood pressure goes down but my heart rate goes up[1]. That can't be good. Heart rate has a strong inverse correlation with lifespan, and this even holds across species (animals with higher heart rates have shorter lifespans). So does lowering blood pressure reduce the risk of heart disease, stroke, etc, but nevertheless shorten your lifespan in other ways because of a higher heart rate? [1] I've verified this for myself with careful record keeping over long periods of starting/stopping different BP meds, but I'm not entirely sure it's true for everyone.
- CookieCrisp 2y ago
  My understanding of the heart rate correlation to lifespan between different species is that it is “within a couple levels of magnitude” and that an increase of 10% in a human’s rate does not correlate at all to a 10% decrease in lifespan
- Aerroon 2y ago
  Have you mentioned this to your doctor? There are different types of blood pressure medications. Some will lower your heart rate. Back when I took beta blockers they reduced my heart rate from 65-70 to 45-55.
- brandonb 2y ago
  This sounds like reflex tachycardia -- your body wants to ensure blood is flowing to all the right places, so it raises heart rate to partially compensate for blood pressure falling. Reflex tachycardia can be a normal response to certain types of blood pressure medications, like vasodilators or diuretics. Beta blockers are a different common type of blood pressure medication that attempt to lower both blood pressure and heart rate simultaneously. If the increase in heart rate is large (>30bpm), especially when going from laying to standing, it could be a sign of underlying dysautonomia or POTS. If you experience symptoms (dizziness, fatigue, fainting, etc) it's worth getting evaluated. We (the OP) do offer medical care for POTS here: https://empirical.health/pots https://empirical.health/pots As for the relationship between low heart rate and longer life spans, it's not necessarily causal -- a lower heart rate is often a sign of a stronger cardiac muscle (each beat pumps more blood, so fewer beats per minute are required to pump the same volume of blood). So I'd suspect much of the relationship here is driven by these confounding variables!
nisegami 2y ago
Two tidbits from me: Several years ago, I got an omron wrist cuff blood pressure monitor. Some doctors showed heavy skepticism at the time but I've never seen any reason to think it's inaccurate when properly mounted and with healthy batteries. I had a sleep study done last year using a brand new machine the lab got (literally unboxed while I was there) that uses a combination of the ecg signals and pulse timing to calculate blood pressure continuously once calibrated. Seemed pretty cool to me and I got the impression this technique is fairly new?
- trq01758 2y ago
  I guess that "properly mounted" may be a problem for a lot of people. According to operating manual measurements should be taken at heart level with 30±5 cm distance between top of the seat and top of the table. Outside of that ±5 cm difference you may get inaccurate results.
- Steve44 2y ago
  I've an arm cuff monitor but recently bought a wrist one, both Omron, because my wife didn't like the arm cuff. What I found was the wrist cuff was incredibly sensitive to both positioning and to any movement, it was harder to get a consistent reading.
danihh 2y ago
Great read. Side note: please fix your header. Makes the website appear so much less professional than the information it provides really is.
- brandonb 2y ago
  Thanks! Would you be able to send me a screenshot of what you're seeing? It may be formatting differently on your screen than mine. bmb@empirical.health.
loughnane 2y ago
Haven’t read the article yet but there are three big things that hinder the usefulness of this tech as it stands: 1. Most clearances only apply to when people are motionless. 2. Often need to calibrate frequently. 3. No practitioner knows what to do with continuous bp data even if they had it. Solve those and we’ve got something big. Until then progress is welcome but not revolutionary.
mikesabbagh 2y ago
I got a Xiaomi GT3 watch for less than 40$ including shipping. it has blood pressure measuring. How accurate? I dont know. I have a normal BP, and it always shows me normal values. Whe I try it on my son or wife's wrist, it always measures a lower BP. Anyways, I stopped looking at it, and I only use it for the looks and to show me notifications.
- Etheryte 2y ago
  Have you considered comparing it to a regular blood pressure monitor in parallel? My guess is that since it isn't certified as a medical device, it's essentially just a random number generator. No smart watch from a big name brand offers this feature yet, so I doubt a $40 device has figured it out.
- ndsipa_pomu 2y ago
  I've got a dubious watch bought from AliExpress that was even cheaper and that claims to monitor blood pressure as well as blood glucose levels, blood lipids and even uric acid levels (that's why I bought it as I get gout). It's obviously not going to be calibrated and accurate, and I did get my brother (who's Type 1 diabetic) to compare the watch readings with his own glucose measurement and it was over 10% out, but that could also be a timing issue as he had just recently eaten. Definitely not a device that you would use to determine insulin injections.
yu3zhou4 2y ago
What's currently the best in the market wearable (watch, ring or maybe something else) to track (useful) health indicators?
sundvor 2y ago
Hypertension is more dangerous than smoking, I read - as I was shocked to discover I had let it slide massively at my last attempt to donate blood at Australia Red Cross. Fast forward 9 months, and I'm now using my Galaxy Ultra watch to monitor my blood pressure, and I've been able to reverse hyper tension thanks in part to how much of an improvement it has made when it comes to quickly getting the pressure reading. Compared to the Omron I calibrate it against, it's a far better experience. It's also a huge step up in performance over the 6 Classic that I upgraded from. That one would have a failed reading 3 times out of 4, whereas the Ultra gets it right just about every single time. The biggest pain is the monthly calibration process, seriously it feels like if I bat an eyelid, or not have the cuff on with just the right tightness, or just have the arm at a slightly different angle, or just get anxious about this whole thing, the Omron (a modern unit with built in Bluetooth etc) will give a different reading. When I get the process done right, however, the Galaxy will return readings that are very close to the Omron both systolic and diastolic - and then it's a month until next time. Being able to quickly and easily get my blood pressure in a number of different situations made a huge change in my motivation to get it under control; I primarily focused on diet and exercise. I ran/run the test several times per day, and learned so much from it. Absolutely love my Ultra watch, it looks gorgeous and performs amazing in general as well. Fwiw I'd regularly see values like 140-155 over 90, now I'm typically around 120 over 80 give or take.
mberning 2y ago
If Apple ever gets continuous bp or glucose monitoring I will probably start to wear one.
jackcosgrove 2y ago
How long does calibrating an on-the-wrist sensor take with a cuff? I used to work at Higi which has many blood pressure cuffs in public locations. I'm wondering if it's practical to calibrate a smartwatch sensor at one of these, or if it would take too long when you're grocery shopping or at the pharmacy. I'm also wondering if new generation cuffs are required. The cuffs we used would be pretty old at this point.
- seanc 2y ago
  Now I'm wondering how well calibrated those automatic public cuffs are in the first place...
No1 2y ago
For anyone interested in on-the-wrist blood pressure tracking who doesn't want to spend the money on a Samsung Galaxy and hack SHMs, or wait for Apple to implement it, there are a plethora of Chinese smartwatches that already have the blood pressure monitoring and calibration capability that can be had for < $15. My experience with them is that although I wouldn't trust these to diagnose a medical condition, the trends are correct and correlate to cuff readings - they're not just random number generators. I just wish there were a way to export the data from the H Band app. Apparently, the data is stored in SQLite files.
- stareatgoats 2y ago
  > there are a plethora of Chinese smartwatches that already have the blood pressure monitoring and calibration capability that can be had for < $15 Sounds interesting. Any idea where can I find such, and additionally, how I can differentiate from the ones with fake claims?

156 points by brandonb 2y ago

Tangentially Related: https://arstechnica.com/health/2024/10/your-doctors-office-could-be-reading-your-blood-pressure-all-wrong/ https://arstechnica.com/health/2024/10/your-doctors-office-c...

brandonb 2y ago
Yeah -- in addition to inappropriate measurement technique, "white coat hypertension" can cause elevated blood pressure readings. And, of course, you have the fact that the American College of Cardiology (ACC) updated their blood pressure guidelines in 2017 to use a lower threshold. So some people with moderately high blood pressure would now be considered to have hypertension and are recommended to seek treatment.
- user3939382 2y ago
  The threshold was 160. Then 140, then in 2017 130 so suddenly millions of new people whom were fine the day before now have a hypertensive crisis and need to be prescribed pharmaceuticals for the rest of their lives. The profit arising from this change is just a happy coincidence arising from the evidence.

kbrisso 2y ago

Measuring blood pressure on the wrist is tricky. I usually do three measurements to get an accurate reading. I have two machines I use. The older one is actually better than the new one. Another thing is, pay attention to how you feel. I can feel my blood pressure when it's high and usually know when the device reading is off. I do this because my family has a history of high blood pressure and so far because of lifestyle choices I have avoided the need for meds.

wil421 2y ago
Why do you have to do it so often? Why do you even do it if you’re not on meds? Third, what would you even do if it’s high?
- kbrisso 2y ago
  I don't check my blood pressure every day. Maybe twice a month or when I feel like crap. I also check my glucose. Why? I believe if I keep myself in check I will keep myself out of the hospital as I age. High blood pressure and diabetes are two things I can manage. I don't want to be on meds unless I absolutely have to. Exercise and these tools allow me to figure out what I can eat and not. I'm not obsessed with my health or a health "nut". The upside is I don't get sick that much and feel good.
j_bum 2y ago
What are some examples of the non-pharmacological/lifestyle approaches you’ve taken?

corry 2y ago

Actually, there is a wrist device called "Aktiia" that's approved for use for continuous BP monitoring with clinical accuracy by the UK and German health authorities (I believe). It's a bit of a pain to get over the pond, but with a shipment-forwarding company + a UK App Store account you can get up and running. I've dabbled a bit with it and it's very close to the cuff measurements. It works by calibrating with their custom arm cuff device. I'd guess that it's correlating what the wrist sensor sees w.r.t. your wrist blood vessels and what the "true" reading is from your arm. You re-do the calibration every few weeks. The device takes a reading every 20 or 30 minutes or so and seems to try to pick periods where you're more stationary. However, one thing to be aware of is that you are not used to seeing your BP readings from the entire day. Did you jump in a cold plunge 10 minutes before it ran? Get ready to see a really high reading dot in the 'danger zone'. Went for a jog and are catching your breath on a park bench? High dot. This isn't a bad thing, it just takes some getting used to since your "daily average" will be significantly above the readings you're used to if you're doing arm cuff measurements at the start/end of the day. Of course it's also getting readings at those more usual times too, but they get washed out in the larger number of data points from your day. And goes without saying, your blood pressure SHOULD go up and down based on your activity and time of day. You just aren't used to seeing it other than at true rest. But all in all it's been fascinating to see, and there's no doubt in my mind that this technology will be mainstream quickly (and Apple will likely dominate it).

Etheryte 2y ago
This is super exciting, thanks for posting! I developed high blood pressure after Covid and have done a few 24h studies to better understand it. The traditional machines are super bulky, essentially like carrying a regular BP monitor around with a pouch that's strapped to you, maybe just a bit smaller. All in all it's far from convenient and can kick in at inopportune times. Having around the clock insights would hopefully give me a better understanding of the condition. For context, I've jumped through all sorts of specialty doctor hoops and there is no known underlying cause outside of the fact that it just showed up after Covid. Do you or anyone you know happen to have firsthand experience with the device?
- 2y ago

oidar 2y ago

I would love to have continuous BP monitoring. I ready for this tech to mature. I'd wager that blood pressure varies way more during the day than weight (which can vary as much as 5 lbs or more) - and continuous, easy BP monitoring at would cause HT dxs to drop significantly.

candiddevmike 2y ago
Why do you think this would cause HT diagnosis to drop? If anything all of these continuous monitors create more patient visits and probably more diagnosis. I'm interested in what the future holds when these things are capable of FDA-approved diagnosing. Will Apple send a prescription for BP meds to my pharmacy?
- oidar 2y ago
  I think there is a lot of white coat HT that makes up many cases. I think the ACS recommends a measurement 3 times in a row at different office visits. So, maybe anxiety might be a direct cause of HT dx.
rootusrootus 2y ago
> HT dxs I'm unfamiliar with this abbreviation but did my best with Google. Does it mean 'hypertension diagnoses'?
- oidar 2y ago
  yes
wil421 2y ago
The problem with this is exercise messes with blood pressure. “Extremely high blood pressure elevations of up to 345/245 mmHg were observed during the lifts.”[1] My doc even said it can get as high as 400 and it’s important to breathe correctly. [1]https://pubmed.ncbi.nlm.nih.gov/2632751/ https://pubmed.ncbi.nlm.nih.gov/2632751/
- 2y ago

stewh_eng 2y ago

I'm a med device engineer and have watched the hopes and dreams of cuffless BP monitoring tech. I hope we get there as it will be hugely important. However, remember tech is only a small part of the battle. We need to figure out clinically what to do with all this new continuous data. I am very sceptical PPG alone will be capable for many reasons. Aktiia does indeed have European regs clearance. But, they don't have FDA clearance. The FDA is a very different beast (more hands on - and they'll be absolutely much more heavy with such a new approach) - and they must have concerns on the approach for it to take this long. The FDA even has accelerated programmes for breakthrough high impact tech as they really do want it to get to market safely. The main cuffless FDA cleared devices I know measure the pulse transit time betwen a central ECG patch and a peripheral based PPG (that time is then calibrated to a BP with the Moens Kourteweg equation) - see Biobeats watch and a now defunct wearable ICU monitor company I can't find the name of. The issue with PPG is that it is wildly sensitive. The PPG waveform morphology will changed dramatically based on the pressure of the sensor against the skin, unconstrained changes in orientation of the human and arm etc. Changes in morphology != changes in system wide BP. Speak to an anaesthesiologist and they'll tell you blood pressure is function many things eg cardiac output, stroke volume, heart rate, blood volume, total peripheral resistance etc etc (https://www.sharinginhealth.ca/multimedia/images/blood_pressure.jpg https://www.sharinginhealth.ca/multimedia/images/blood_press...). The question is whether PPG alone can measure all these things. I suspect it's really just measuring lots of proxies of all these things. And that's fine - however in the presence of people with conditions or on therapeutics that alter these in very personalised and unpredictable ways then error may start to creep in on free living measurement. Paradoxically, it's probably these people for whom this tech would have most impact - not the worried well.

utschig 2y ago
Sotera Wireless
- stewh_eng 2y ago
  That's the one! They were lightyears ahead but seemingly couldn't make the commercials work. Thank you!

gausswho 2y ago

I am fascinated by the concept of blood pressure as one of the foremost tools of health. Can someone recommend perhaps a book size read on the history of how we came to learn of its value and help illuminate well... what it even is?

jcims 2y ago

Side note, I started monitoring with a cuff-style monitor over the past month, and one thing that’s super important is keeping the cuff at about heart level. The cuff I got actually reminds you of this verbally. While it obviously makes sense, it’s a bit surprising how much a change in elevation affects the readings.

isoprophlex 2y ago
Try sticking it around your ankle and measuring while standing up. I get 250 mmHg systolic, easily

daemonk 2y ago

For most instruments, it's an interplay between resolution and consistency. There isn't a "true" reading in any sense of the word. There is just how much resolution you are measuring and how consistent the measurement is between independent readings of the same event. The overwhelming amount of pre-existing clinical data gathered by cuff-monitors means that any novel measurement methods benefit from tying/correlating their output to the existing data for compatibility. It's a bit unfortunate in some sense as cuff-monitor data lacks resolution and sometimes can be a bit of a drag on novelty.

mysterypie 2y ago

I'm hoping someone can answer a question that's been bugging me for years: When I take blood pressure medication my blood pressure goes down but my heart rate goes up[1]. That can't be good. Heart rate has a strong inverse correlation with lifespan, and this even holds across species (animals with higher heart rates have shorter lifespans). So does lowering blood pressure reduce the risk of heart disease, stroke, etc, but nevertheless shorten your lifespan in other ways because of a higher heart rate? [1] I've verified this for myself with careful record keeping over long periods of starting/stopping different BP meds, but I'm not entirely sure it's true for everyone.

CookieCrisp 2y ago
My understanding of the heart rate correlation to lifespan between different species is that it is “within a couple levels of magnitude” and that an increase of 10% in a human’s rate does not correlate at all to a 10% decrease in lifespan
Aerroon 2y ago
Have you mentioned this to your doctor? There are different types of blood pressure medications. Some will lower your heart rate. Back when I took beta blockers they reduced my heart rate from 65-70 to 45-55.
brandonb 2y ago
This sounds like reflex tachycardia -- your body wants to ensure blood is flowing to all the right places, so it raises heart rate to partially compensate for blood pressure falling. Reflex tachycardia can be a normal response to certain types of blood pressure medications, like vasodilators or diuretics. Beta blockers are a different common type of blood pressure medication that attempt to lower both blood pressure and heart rate simultaneously. If the increase in heart rate is large (>30bpm), especially when going from laying to standing, it could be a sign of underlying dysautonomia or POTS. If you experience symptoms (dizziness, fatigue, fainting, etc) it's worth getting evaluated. We (the OP) do offer medical care for POTS here: https://empirical.health/pots https://empirical.health/pots As for the relationship between low heart rate and longer life spans, it's not necessarily causal -- a lower heart rate is often a sign of a stronger cardiac muscle (each beat pumps more blood, so fewer beats per minute are required to pump the same volume of blood). So I'd suspect much of the relationship here is driven by these confounding variables!

nisegami 2y ago

Two tidbits from me: Several years ago, I got an omron wrist cuff blood pressure monitor. Some doctors showed heavy skepticism at the time but I've never seen any reason to think it's inaccurate when properly mounted and with healthy batteries. I had a sleep study done last year using a brand new machine the lab got (literally unboxed while I was there) that uses a combination of the ecg signals and pulse timing to calculate blood pressure continuously once calibrated. Seemed pretty cool to me and I got the impression this technique is fairly new?

trq01758 2y ago
I guess that "properly mounted" may be a problem for a lot of people. According to operating manual measurements should be taken at heart level with 30±5 cm distance between top of the seat and top of the table. Outside of that ±5 cm difference you may get inaccurate results.
Steve44 2y ago
I've an arm cuff monitor but recently bought a wrist one, both Omron, because my wife didn't like the arm cuff. What I found was the wrist cuff was incredibly sensitive to both positioning and to any movement, it was harder to get a consistent reading.

danihh 2y ago

Great read. Side note: please fix your header. Makes the website appear so much less professional than the information it provides really is.

brandonb 2y ago
Thanks! Would you be able to send me a screenshot of what you're seeing? It may be formatting differently on your screen than mine. bmb@empirical.health.

loughnane 2y ago

Haven’t read the article yet but there are three big things that hinder the usefulness of this tech as it stands: 1. Most clearances only apply to when people are motionless. 2. Often need to calibrate frequently. 3. No practitioner knows what to do with continuous bp data even if they had it. Solve those and we’ve got something big. Until then progress is welcome but not revolutionary.

mikesabbagh 2y ago

I got a Xiaomi GT3 watch for less than 40$ including shipping. it has blood pressure measuring. How accurate? I dont know. I have a normal BP, and it always shows me normal values. Whe I try it on my son or wife's wrist, it always measures a lower BP. Anyways, I stopped looking at it, and I only use it for the looks and to show me notifications.

Etheryte 2y ago
Have you considered comparing it to a regular blood pressure monitor in parallel? My guess is that since it isn't certified as a medical device, it's essentially just a random number generator. No smart watch from a big name brand offers this feature yet, so I doubt a $40 device has figured it out.
ndsipa_pomu 2y ago
I've got a dubious watch bought from AliExpress that was even cheaper and that claims to monitor blood pressure as well as blood glucose levels, blood lipids and even uric acid levels (that's why I bought it as I get gout). It's obviously not going to be calibrated and accurate, and I did get my brother (who's Type 1 diabetic) to compare the watch readings with his own glucose measurement and it was over 10% out, but that could also be a timing issue as he had just recently eaten. Definitely not a device that you would use to determine insulin injections.

yu3zhou4 2y ago

What's currently the best in the market wearable (watch, ring or maybe something else) to track (useful) health indicators?

sundvor 2y ago

Hypertension is more dangerous than smoking, I read - as I was shocked to discover I had let it slide massively at my last attempt to donate blood at Australia Red Cross. Fast forward 9 months, and I'm now using my Galaxy Ultra watch to monitor my blood pressure, and I've been able to reverse hyper tension thanks in part to how much of an improvement it has made when it comes to quickly getting the pressure reading. Compared to the Omron I calibrate it against, it's a far better experience. It's also a huge step up in performance over the 6 Classic that I upgraded from. That one would have a failed reading 3 times out of 4, whereas the Ultra gets it right just about every single time. The biggest pain is the monthly calibration process, seriously it feels like if I bat an eyelid, or not have the cuff on with just the right tightness, or just have the arm at a slightly different angle, or just get anxious about this whole thing, the Omron (a modern unit with built in Bluetooth etc) will give a different reading. When I get the process done right, however, the Galaxy will return readings that are very close to the Omron both systolic and diastolic - and then it's a month until next time. Being able to quickly and easily get my blood pressure in a number of different situations made a huge change in my motivation to get it under control; I primarily focused on diet and exercise. I ran/run the test several times per day, and learned so much from it. Absolutely love my Ultra watch, it looks gorgeous and performs amazing in general as well. Fwiw I'd regularly see values like 140-155 over 90, now I'm typically around 120 over 80 give or take.

mberning 2y ago

If Apple ever gets continuous bp or glucose monitoring I will probably start to wear one.

jackcosgrove 2y ago

How long does calibrating an on-the-wrist sensor take with a cuff? I used to work at Higi which has many blood pressure cuffs in public locations. I'm wondering if it's practical to calibrate a smartwatch sensor at one of these, or if it would take too long when you're grocery shopping or at the pharmacy. I'm also wondering if new generation cuffs are required. The cuffs we used would be pretty old at this point.

seanc 2y ago
Now I'm wondering how well calibrated those automatic public cuffs are in the first place...

No1 2y ago

For anyone interested in on-the-wrist blood pressure tracking who doesn't want to spend the money on a Samsung Galaxy and hack SHMs, or wait for Apple to implement it, there are a plethora of Chinese smartwatches that already have the blood pressure monitoring and calibration capability that can be had for < $15. My experience with them is that although I wouldn't trust these to diagnose a medical condition, the trends are correct and correlate to cuff readings - they're not just random number generators. I just wish there were a way to export the data from the H Band app. Apparently, the data is stored in SQLite files.

stareatgoats 2y ago
> there are a plethora of Chinese smartwatches that already have the blood pressure monitoring and calibration capability that can be had for < $15 Sounds interesting. Any idea where can I find such, and additionally, how I can differentiate from the ones with fake claims?