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The science behind on-the-wrist blood pressure tracking

empirical.health

11–20 of 106 posts

Re: The science behind on-the-wrist blood pressure tracking

#11

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…

Sotera Wireless

Re: The science behind on-the-wrist blood pressure tracking

#12
post #11

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…

Sotera Wireless

That's the one! They were lightyears ahead but seemingly couldn't make the commercials work. Thank you!

Re: The science behind on-the-wrist blood pressure tracking

#13
post #4

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 thei…

Was unaware of the Aktiia. Thank you for posting. I saw firsthand how CGM changed my behavior and would love the same for ketones and blood pressure.

I am particularly excited about the UT Austin research[1] that used conductive temporary tattoos to get actual real time data and not just polling at intervals. However it’s not yet at the stage of commercialization and the design is more the width of a cuff than a watch.

[1] https://scitechdaily.com/electronic-tattoo-offers-highly-acc...

Re: The science behind on-the-wrist blood pressure tracking

#14
post #4

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 thei…

> 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 is a great point. Blood pressure readings are only useful in the context of stationary measurements under known conditions. Blood pressure is inherently volatile and depends on activity and recent movements, or to extreme events like cold exposure.

There are even finger-cuff blood pressure monitors designed for continuous, constant blood pressure measurement in the context of a lab or hospital setting. Their measurements would be useless in the context of someone moving around all day, but it can be useful in the context of someone under anesthesia or undergoing a controlled lab test.

Re: The science behind on-the-wrist blood pressure tracking

#16
post #4

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 thei…

IIRC there's also a Samsung Galaxy Watch that does blood pressure monitoring, with similar requirements. Have to work a bit to get the app installed in the US, but then it takes periodic measurements, is fairly accurate, and requires calibration once a month.

I was really hoping Apple was going to bring BP to the watch this year, but my guess is the regular external calibration requirement is too much for their plug-and-play philosophy.

Re: The science behind on-the-wrist blood pressure tracking

#17
post #5

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.

> HT dxs

I'm unfamiliar with this abbreviation but did my best with Google. Does it mean 'hypertension diagnoses'?

Re: The science behind on-the-wrist blood pressure tracking

#18
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.

Re: The science behind on-the-wrist blood pressure tracking

#19
post #4

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 thei…

> 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.

Yeah, people panic reading a single 150 systolic, yet routinely it can reach 220+ during heavy exercise. It's perfectly fine. The health metric is the BP at rest, i.e. how low it goes when you're completely idle.

I find it takes up to 20 minutes to reach its lowest sometimes, in state of absolute calm: no movement, no talking, no anxiety. Hence the 'white collar hypertension', i.e. high BP when measured in hospitals and GPs office, where they don't give you enough time to settle down, or are not spaces that induce calm mental states.

The way I take my BP reading is every 5 minutes, until I get a similar reading after 2 consecutive measurements. It takes longer than you'd expect.

Re: The science behind on-the-wrist blood pressure tracking

#20
post #18

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.

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