Blood Pressure Monitoring

[adrianlondon]

Maybe the watch will beep and guide you to the nearest Apple store to get your upper-arm blood-pressure reading done.

The older your devices are, the higher your blood pressure will be as you'll be seeing all the nice new phones and laptops on display. The recommendation to lower blood pressure will be an Apple Store employee telling you to buy new stuff.

If you're American, this is probably cheaper than getting proper medical advice 😁

 

[Macalway]

Thinking about it (I know it's difficult), I get it now, I think. Transient blood pressure readings have little meaning for most people (although there are several notable exceptions, obviously), so I guess you could make this work.

But then the entire question is: does it work? If it does, then they are going to sell even more of these. Also, demographics may shift more towards the aging masses.

 

[AM2354]

It is called Photoplethysmography. Google it.

Edit: perhaps I should not have used the expression “exactly the same”, but they are substantially equal.
The point being that it would not be any larger than any pulse oximeter, such as the one already on the AW.

EDIT: my clumsy suggestion to “Google it” was made because this would provide anyone interested, with a large amount of information and studies about this technology. Much more and much better than I would be able to convey in my own words. Sorry if that sounded abrupt.

We have been using this technology for O2 Saturations, and for me as Paramedic, I have been using it now for 35 years. I have to say that it's not so reliable. Skin can have several reasons of blocking that light, as well as medical conditions.

 

[G4RHL]

That could be a sign that you have sleep apnea, so talk about this with your doctor or cardiologist.

Nope, I don’t have sleep apnea.

 

[G4RHL]

The hardware technology is exactly the same used for blood oxygen, so it is already on the watch.
The accuracy of the estimated BP reading is another matter altogether though.

It’s a lot smaller.

 

[G4RHL]

Blood pressure measured at the wrist, with any device (including hospital-grade), is not nearly as accurate as the bicep.

Doesn't that require monthly calibration?

Yes.

 

[G4RHL]

It should be more accurate than the cuff in view of how it takes readings and works out the results. I have found the readings similar to using a cuff. I did not expect that first but it seems to learn. It does come with a cuff as well but I have used a third party one to compare. Would rather the Apple Watch did it all though! One day!

 

[MINZ]

I am sorry my reply could be interpreted as being confrontational.
My intention was to point out that once I have provided the name of the technology it is easier for anyone interested to Google the name and find out everything there is to know about it, as opposed to taking my word or interpretation for it.
I will remember to make this point clearer in the future.

Please don't feel the need to explain yourself. If some on this site are so touchy about word presentation when discussing something entirely different,,,they need to get a life.. IMHO

 

[Jackbequickly]

Yes.

How would someone calibrate for blood pressure. It is so dynamic that it changes in seconds.

 

[adrianlondon]

How would someone calibrate for blood pressure. It is so dynamic that it changes in seconds.

The same way a doctor would, I guess.

Relax, wear the upper-arm band, hold your arm in the correct position (I believe the cuff should be around heart-level - I don't own one so am not sure) and take an average reading over a short time period.

 

[Jackbequickly]

The same way a doctor would, I guess.

Relax, wear the upper-arm band, hold your arm in the correct position (I believe the cuff should be around heart-level - I don't own one so am not sure) and take an average reading over a short time period.

Sorry but I am not believing. 🙄

 

[Macalway]

Sorry but I am not believing. 🙄

I think the theory behind a watch monitor is relevant (maybe even more than a cuff.) 'for generally healthy' non-emergency situations, a cuff is useful if you use it for about a week at certain times of the day, to give you an average. This is rather time consuming and prone to inaccuracies, do to calibration, user error, time of day, etc.. A watch just keeps on ticking. Point is, you have basically two situations. One is emergency readings, and the other is long term trends. Of course the watch is complete useless in the former, yet could be useful in the later, where the cuff is the opposite.

 

[Wando64]

How would someone calibrate for blood pressure. It is so dynamic that it changes in seconds.

I think you are raising a valid point. If I am to be taken as an example, I know that my BP is highly variable, even within the short space of a minute.
I don't know how it works for this system, but as it is based on optical readings, it would be not inconceivable that one could to a sphygmomanometer reading concurrently, which would accurately validate the first.

 

[AM2354]

I have been taking blood pressure readings on thousands of patients. I am a career Paramedic celebrating 35 years in Critical Care. Here is what I have for all of you. While some smartwatches offer blood pressure monitoring, their accuracy is generally not as reliable as traditional cuff-based monitors. Cuff-style monitors, particularly those that wrap around the upper arm, are the standard for accurate blood pressure readings. Although some smartwatches have made strides in this area, they often require calibration with a cuff-based monitor and may still show variations in readings. The American Heart Association recommends using an automatic, cuff-style monitor that fits around the upper arm. This is because they offer the most consistent and accurate readings when used correctly.

When I am taking a blood pressure reading I use the upper arm and use my stethoscope to auscultate the brachial artery. When I can't do this we do what is called BP by palpation. The cuff is again in the upper arm and we feel for the radial artery, and we pump up the cuff until we can't fell it anymore and slowly release it. When we feel the first pulsating pulse we record that number. Say it was 120 when I first felt it, so I would say 120 Palp, and that would be your systolic number.

 

[Outdoordude01]

I have been taking blood pressure readings on thousands of patients. I am a career Paramedic celebrating 35 years in Critical Care. Here is what I have for all of you. While some smartwatches offer blood pressure monitoring, their accuracy is generally not as reliable as traditional cuff-based monitors. Cuff-style monitors, particularly those that wrap around the upper arm, are the standard for accurate blood pressure readings. Although some smartwatches have made strides in this area, they often require calibration with a cuff-based monitor and may still show variations in readings. The American Heart Association recommends using an automatic, cuff-style monitor that fits around the upper arm. This is because they offer the most consistent and accurate readings when used correctly.

When I am taking a blood pressure reading I use the upper arm and use my stethoscope to auscultate the brachial artery. When I can't do this we do what is called BP by palpation. The cuff is again in the upper arm and we feel for the radial artery, and we pump up the cuff until we can't fell it anymore and slowly release it. When we feel the first pulsating pulse we record that number. Say it was 120 when I first felt it, so I would say 120 Palp, and that would be your systolic number.

Yep, and the best thing is that good Cuff-style monitors are pretty dang cheap now.

 

[AM2354]

All this medical information to be jammed into a watch is not accurate at all. Let me say that it's all a money maker. I have spent 35 years in Critical Care to know that a BP is done one way for accuracy, and to get an O2 Saturation, this is also done a certain way. The O2 reading for us are not always accurate for us for several reasons, but look at the notes from the Mayo Clinic on blood O2 saturation on two watches.

Objective​

To assess the ability of 2 commercially available smartwatches to accurately detect clinically significant hypoxia in patients hospitalized with coronavirus-19 (COVID-19).

Patients and Methods​

A prospective multicenter validation study was performed from November 1, 2021, to August 31, 2022, assessing the Apple Watch Series 7 and Withings ScanWatch inbuilt pulse oximetry, against simultaneous ward-based oximetry as the reference standard. Patients hospitalized with active COVID-19 infection not requiring intensive care admission were recruited.

Results​

A total of 750 smartwatch pulse oximetry measurements and 400 ward oximetry readings were successfully obtained from 200 patients (male 54%, age 66±18 years). For the detection of clinically significant hypoxia, the Apple Watch had a sensitivity and specificity of 34.8% and 97.5%, respectively with a positive predictive value of 78.1% and negative predictive value of 85.6%. The Withings ScanWatch had a sensitivity and specificity of 68.5% and 80.8%, respectively with a positive predictive value of 44.7% and negative predictive value of 91.9%. The overall accuracy was 84.9% for the Apple Watch and 78.5% for the Withings ScanWatch. The Spearman rank correlation coefficients reported a moderate correlation to ward-based photoplethysmography (Apple: rs=0.61; Withings: rs=0.51, both P<.01).

Conclusion​

Although smartwatches are able to provide SpO2 readings, their overall accuracy may not be sufficient to replace the standard photoplethysmography technology in detecting hypoxia in patients with COVI D-19.


Photoplethysmography is the light sensor that detects the O2 in your blood. This SPO2 being shown is what we use on the Paramedic truck and also in the ER.This goes on you finger and the light can sense the O2 within your blood.

 

[Wando64]

All this medical information to be jammed into a watch is not accurate at all. Let me say that it's all a money maker. I have spent 35 years in Critical Care to know that a BP is done one way for accuracy, and to get an O2 Saturation, this is also done a certain way. The O2 reading for us are not always accurate for us for several reasons, but look at the notes from the Mayo Clinic on blood O2 saturation on two watches.

Objective​

To assess the ability of 2 commercially available smartwatches to accurately detect clinically significant hypoxia in patients hospitalized with coronavirus-19 (COVID-19).

Patients and Methods​

A prospective multicenter validation study was performed from November 1, 2021, to August 31, 2022, assessing the Apple Watch Series 7 and Withings ScanWatch inbuilt pulse oximetry, against simultaneous ward-based oximetry as the reference standard. Patients hospitalized with active COVID-19 infection not requiring intensive care admission were recruited.

Results​

A total of 750 smartwatch pulse oximetry measurements and 400 ward oximetry readings were successfully obtained from 200 patients (male 54%, age 66±18 years). For the detection of clinically significant hypoxia, the Apple Watch had a sensitivity and specificity of 34.8% and 97.5%, respectively with a positive predictive value of 78.1% and negative predictive value of 85.6%. The Withings ScanWatch had a sensitivity and specificity of 68.5% and 80.8%, respectively with a positive predictive value of 44.7% and negative predictive value of 91.9%. The overall accuracy was 84.9% for the Apple Watch and 78.5% for the Withings ScanWatch. The Spearman rank correlation coefficients reported a moderate correlation to ward-based photoplethysmography (Apple: rs=0.61; Withings: rs=0.51, both P<.01).

Conclusion​

Although smartwatches are able to provide SpO2 readings, their overall accuracy may not be sufficient to replace the standard photoplethysmography technology in detecting hypoxia in patients with COVI D-19.


Photoplethysmography is the light sensor that detects the O2 in your blood. This SPO2 being shown is what we use on the Paramedic truck and also in the ER.This goes on you finger and the light can sense the O2 within your blood.

Thanks for the information. I have no reason nor knowledge to disagree on their findings, however isn't this a little bit like comparing the Apple Watch 1 lead ECG with a standard 12 leads ECG?
1 lead might not say a lot, but it was surely useful as an aid and a starting point to discuss my palpitations with my doctor.

The point I am trying to make is that perhaps a trend of a reduced SpO2 over time might be useful to alert of something being wrong.
Perhaps not, but either way I don't think the point was ever to replace the precision of standard clinical technology, nor the advice of a medic.

 

[AM2354]

Thanks for the information. I have no reason nor knowledge to disagree on their findings, however isn't this a little bit like comparing the Apple Watch 1 lead ECG with a standard 12 leads ECG?
1 lead might not say a lot, but it was surely useful as an aid and a starting point to discuss my palpitations with my doctor.

The point I am trying to make is that perhaps a trend of a reduced SpO2 over time might be useful to alert of something being wrong.
Perhaps not, but either way I don't think the point was ever to replace the precision of standard clinical technology, nor the advice of a medic.

I think I may know what you are saying and correct me if I am wrong, but something in better than nothing is the bottom line. To see something that may be unusual and to get help just may save your life. I am ok with this.

 

[G4RHL]

I am surprised it has taken so long for Apple to introduce blood pressure monitoring in the watch considering that others have mastered this some time ago. One such device, which I now wear, has been out for a couple of years, and is accurate. If the manufacturer of such can achieve this it is a little surprising Apple have taken so long to bearing in mind their research and ingenuity. Unless of course it is regulatory issues in the USA that holds them up. I would much rather have one device, the Apple Watch, doing all the monitoring and not have two.

An update to my original post. I have used the HiLo for well over a month now. I’d say it takes about a month to learn. It requires calibration with a cuff once a month. I have done it more often. I have also compared readings with an Omron.

Initially the cuff readings (HiLo and Omron) were about the same as you would expect. The wrist band readings were different initially. Gradually as it learned they became similar. As did taking a BP reading just using a finger held on the camera on the back of the iPhone. This is an experimental feature at present but it is fairly accurate but you do have to sit still.

I have often to double check taken readings together from the two cuffs, the watch and the finger and all are similar.

As I understand it the HiLo band can be more accurate in view of the number of readings it takes and some algorithms somewhere in the Cloud does its stuff. It showed its stuff the other day. Normally it shows my BP dropping when I initially go to sleep and during the night when asleep can rise. On Wednesday evening I had a minor procedure where I was sedated, wide awake to watch and converse but a painkiller and sedation in my system. During the night following the wrist band showed my BP was absolutely great, to be proud of! 24 hours later it was back to what it always read. The sedation had left my system.

I think also the wrist band has had a number of scientific tests to confirm its accuracy, or indeed better accuracy. Such revealed it showing a lower heart rate than the cuffs did. Caused by the cuff itself causing an increase as it compresses the upper arm.

Hope this helps. But it would be great if the Apple Watch did this. From what I read it seems if Apple add the facility it will be limited. We will all know in just over a week!

 

[Momof2.1107]

An update to my original post. I have used the HiLo for well over a month now. I’d say it takes about a month to learn. It requires calibration with a cuff once a month. I have done it more often. I have also compared readings with an Omron.

Initially the cuff readings (HiLo and Omron) were about the same as you would expect. The wrist band readings were different initially. Gradually as it learned they became similar. As did taking a BP reading just using a finger held on the camera on the back of the iPhone. This is an experimental feature at present but it is fairly accurate but you do have to sit still.

I have often to double check taken readings together from the two cuffs, the watch and the finger and all are similar.

As I understand it the HiLo band can be more accurate in view of the number of readings it takes and some algorithms somewhere in the Cloud does its stuff. It showed its stuff the other day. Normally it shows my BP dropping when I initially go to sleep and during the night when asleep can rise. On Wednesday evening I had a minor procedure where I was sedated, wide awake to watch and converse but a painkiller and sedation in my system. During the night following the wrist band showed my BP was absolutely great, to be proud of! 24 hours later it was back to what it always read. The sedation had left my system.

I think also the wrist band has had a number of scientific tests to confirm its accuracy, or indeed better accuracy. Such revealed it showing a lower heart rate than the cuffs did. Caused by the cuff itself causing an increase as it compresses the upper arm.

Hope this helps. But it would be great if the Apple Watch did this. From what I read it seems if Apple add the facility it will be limited. We will all know in just over a week!

I’m still waiting for HiLo to launch in the US.