[HN Gopher] The science behind on-the-wrist blood pressure tracking
___________________________________________________________________
The science behind on-the-wrist blood pressure tracking
Author : brandonb
Score : 74 points
Date : 2024-10-10 14:40 UTC (8 hours ago)
(HTM) web link (www.empirical.health)
(TXT) w3m dump (www.empirical.health)
| bloopernova wrote:
| Tangentially Related:
| https://arstechnica.com/health/2024/10/your-doctors-office-c...
| brandonb wrote:
| 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.
| kbrisso wrote:
| 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 wrote:
| 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 wrote:
| 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.
| corry wrote:
| 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 wrote:
| 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?
| misstuned wrote:
| I've found similar. I don't know if it was post-Covid, but I
| have completely asymptomatic high blood pressure. It's really
| scary to go to the doctor for an extremely routine health
| check expecting to be back at work in an hour, and then
| suddenly be told that your blood pressure is so high that you
| need to go to hospital immediately.
|
| There's no obvious cause, I'm fit and healthy in all other
| ways, I've had multiple blood tests and ECGs, my cholesterol
| is normal, everything is normal, just the blood pressure. I
| also didn't know about this machine but I might get one. I
| have developed anxiety around having it taken (because of the
| experience of getting sent to hospital!) so it goes up when I
| take it, like extreme white-coat syndrome.
|
| I'm definitely getting one of these gadgets so I can see what
| it really is, without the stress and pain (those things
| hurt!) of inflating cuffs.
| corry wrote:
| Hey I have firsthand experience with it as indicated in the
| post. Probably a few months worth of wear at this point.
|
| BP remains a great mystery to me, even with the device. My
| cardio fitness is pretty good despite carrying a few extra
| pounds (I'm in the low 50s for resting heart rate), and while
| overnight I dip down in the 120's, I can see it shoot up
| based on various things like cold plunge, caffeine, exercise
| (during), etc. I can also see it drop temporarily (hot tub,
| meditation, the hours FOLLOWING intense exercise, etc).
|
| I had many pet theories through the years - that I had white
| coat syndrome, that I disliked the feeling of the cuff, etc
| etc. But the device showed me that, no, something really is
| going on independent of these pseudo-causes.
|
| BTW water retention seems to play a big role. When I did
| keto, which causes a big drop in water retention, my BP also
| went down. Strange. Supplements have an impact too.
|
| All this to say - get the device and see for yourself, but
| you might find yourself in the same place I am - which is
| that you have much better understanding of what's going on in
| terms of symptoms but are still on the search for "the
| underlying cause" if there even is such a thing.
| brandonb wrote:
| I'll bet blood pressure readings throughout the day will be
| analogous to the data we get from CGMs (continuous glucose
| monitors). You get lots of spikes during the day.
|
| Given enough data pairing continuous blood pressure with major
| events like heart attacks and strokes, we may even develop more
| accurate models to predict which types of spikes create the
| most cardiovascular risk.
| corry wrote:
| Totally agree, although perhaps the real gift of this
| technology will be from the fact that people can be more
| aware of the underlying conditions (high BP) and tighter
| feedback loops on how to reduce it / manage it vs. just
| helping notify about an acute emergency situation.
|
| As I typed the above sentence out, I thought "why not both?".
| Use the technology to reduce your risk, but in the event that
| the bad event still happens the notification could save your
| life.
| paulgerhardt wrote:
| 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...
| Aurornis wrote:
| > 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.
| nradov wrote:
| Anecdotally I find my blood pressure (measured with a regular
| upper-arm cuff while sitting) to often be lowest soon after
| completing a workout, like a hard 5K run outside. I'm not
| sure why, maybe the vasodilation effect from increased nitric
| oxide production?
| rootusrootus wrote:
| 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.
| indoordin0saur wrote:
| Are the sensors already capable of it? Maybe someone could
| make a third party app for the watch
| ljosifov wrote:
| +1. I also use Samsung Galaxy Watch (Active2) and find it to
| work well for me. I'm surprised more people don't know about
| it. I know couple of people that suffer from high BP. They
| showed little interest when I told them about the watch.
|
| Regular external calibration helped me build confidence. I
| was suspicions if the watch worked, and how well it worked.
| Calibration is every month - it expires. I take 3
| measurements in parallel watch-cuff, and tell the watch App
| what the cuff measured. I didn't mind it initially. I now
| find it annoying tbh. I see why Apple would like to get rid
| of it. Post calibration, I measure 3 times in parallel both
| watch and cuff to check if they match. If the difference is
| within 5% - then fine. In 3 years it's happened twice where
| they differed more and I had to recalibrate. From
| recollection - both times with a reason, a TV was turned on
| in living room.
|
| I have the impression that BP measurements differ though the
| day (lower in the morning, higher in the evening), depending
| on activity or at rest of course, I think there maybe some
| seasonality too (winter v.s. summer). Measuring BP when going
| to the doctor once a year strikes me as a wholly inadequate.
| If the BP is absurdly high out of normal range - then yeah,
| we learn something is wrong with the patient. But in any
| other case - don't see what can be deduced from 1 random
| measurement.
|
| To check if the calibration is important, I had my wife use
| the watch, that is calibrated on me. She got absurd readings.
| So yes - the calibration is important and is tied to the
| person that did the calibration. (edited to add this)
| sph wrote:
| > 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.
| AStonesThrow wrote:
| During a recent visit, I mentioned my "White Coat Syndrome"
| was probably affecting me right there, so they selected their
| most attractive woman with the best perfume and a manual
| sphygmomanometer for a hands-on measurement, before releasing
| me.
| corry wrote:
| 100% hard agree. I'm now paying most attention to my
| overnight rate, like in the middle of the night - but even
| that takes a few hours to get down to the minimum value.
| Fascinating to see the big spike prior to waking up that
| signals your body is preparing for rising.
|
| Did I eat late before bed? Higher BP overnight. Drink any
| alcohol at all after, say, 12pm? Higher BP overnight. So it's
| still useful and interesting to see the overnight values
| change and shift around.
|
| However, the contrarian in my mind says that it's not smart
| to ONLY pay attention to your deep rest state BP, since that
| only applies to a fraction of the day. And if you're running
| around at high values for the rest of the day, you're still
| potentially doing damage to your kidneys, retinas, etc - the
| sensitive blood vessel stuff.
|
| So it's a useful device, it's useful to have the data, but
| it's also still a bit of black box.
|
| The fact that 80% of all high blood pressure is of unknown
| physiological cause is a real head scratcher considering that
| cardiac misadventures are the leading cause of death in the
| Western world.
| throwup238 wrote:
| _> However, one thing to be aware of is that you are not used
| to seeing your BP readings from the entire day._
|
| Same thing with those continuous glucose monitors that almost
| anyone can get and put on their arm now. The vast majority of
| the data and recommendations we have are for diabetics using
| regular single use measurements or a proper glucose tolerance
| test so shortly after the user eats a bowl of rice while
| wearing it, it sends them into a hypochondriac spiral when they
| see a peak of 200. Their doctor generally has to talk them
| down. There's just not that much data on what the average
| healthy person's response to blood sugar is, especially when
| it's continuously monitored.
| outworlder wrote:
| > There's just not that much data on what the average healthy
| person's response to blood sugar is, especially when it's
| continuously monitored.
|
| Chicken and egg situation, no?
|
| People are advised not to use those devices because there
| isn't much data about them for otherwise healthy people. But
| if they don't use those devices, there won't be much data.
| LorenPechtel wrote:
| I found the exact reverse with the jog. One day I went into the
| mountains with a cuff on my wrist and took a bunch of
| measurements. I wasn't jogging but I had something like 25
| pounds on my back and was definitely pushing myself.
|
| There was a huge effect from perceived temperature--while I
| didn't do the cold plunge I got some quite high readings when I
| was on the chilly side. Yet I could get low-normal readings
| with my heart rate above 130 which is the highest I could go at
| that elevation. Obviously I couldn't actually take a reading
| while moving but I could have it on my wrist, stop and
| immediately press the button. The pattern I observed was
| activity raises temperature which lowers blood pressure.
| corry wrote:
| Thanks for sharing. For me, I can see that DURING exercise,
| my blood pressure is quite raised but then drops down lower
| than usual in the hours that follow. However, I think that's
| more a function of resting HR - which remains elevated.
|
| My particular BP scenario is good diastolic, high systolic
| but low rest heart rate (low 50s). My pet theory is that my
| heart does fewer but stronger pumps, which increases the BP.
| After exercising, when heart rate remains elevated, the BP is
| lower since the heart is doing more frequent but less
| powerful beats.
|
| Just a pet theory, I haven't even discussed it with a medical
| professional.
| avidiax wrote:
| I am wondering if continuous blood pressure monitoring would
| have some knock-on effects as a measurable, correlatable
| negative health effect of stress.
|
| It would mean that you can literally show that working
| conditions are shortening your life.
|
| Your company's health insurance could look at BP during
| commuting hours and in the office vs. at home and raise rates
| on companies based on their policies.
| m463 wrote:
| Hmm... I remember reading that cuff blood pressure measurements
| require your arm to be supported. (and also explains why a lot
| of blood pressure measurements are inaccurate)
|
| I wonder if you're calibrating on a supported arm, then letting
| your arm swing free later with the wrist device.
| oidar wrote:
| 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 wrote:
| 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 wrote:
| 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 wrote:
| > HT dxs
|
| I'm unfamiliar with this abbreviation but did my best with
| Google. Does it mean 'hypertension diagnoses'?
| oidar wrote:
| yes
| wil421 wrote:
| 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/
| oidar wrote:
| Yes, BP is much higher when exercising, but presumably in
| these situations the user will indicate that they are
| exercising in whatever app they are syncing with. 24 hour
| ambulatory BP measurement protocol directs pts to not
| exercise during the time to rule out this confounding factor.
| lispisok wrote:
| High blood pressure has been defined as blood pressure over a
| certain threshold when blood pressure is taken a certain way.
| That certain way is at rest when it's lower than moving around.
| All the data and research has correlated health outcomes that
| way. We already know blood pressure is higher when you are up
| and about than after you've been sitting down for 5 minutes. If
| you're trying to get out of your hypertension diagnosis using
| continuous monitoring you are in for disappointment because
| hypertension has been defined by your blood pressure when it's
| at its lowest.
| oidar wrote:
| If you look at the BP measurement protocol for HT dx, most
| people will never have a visit that matches that protocol
| because it costs a lot of time and time is something medical
| practices don't like to give for something as simple as HT
| dx.
|
| https://www.ahajournals.org/doi/pdf/10.1161/HYPERTENSIONAHA..
| ..
|
| 24 hour ambulatory BP measurements are the gold standard for
| accurate HT dxs.
| hombre_fatal wrote:
| Well, baked into your own claim, they don't have hypertension
| if their pressure is only elevated when it's taken (e.g. the
| doctor's office) rather than what it might drop to otherwise.
|
| I have a blood pressure monitor that takes the lowest of
| three measurements. It's really annoying to use, takes
| forever, feels uncomfortable, and my blood pressure often
| drops another 10 points if I do it all over again because
| I've been laying in the bed another 5min.
|
| Passive measurements address all of this. You also get to see
| what activities have what impact on your blood pressure. How
| does your daily blood pressure graph look like on and off
| ADHD meds, for example?
|
| I can't wait until this info is part of the wrist wearable
| kit.
| stewh_eng wrote:
| 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_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 wrote:
| Sotera Wireless
| stewh_eng wrote:
| That's the one! They were lightyears ahead but seemingly
| couldn't make the commercials work. Thank you!
| saltcured wrote:
| I wonder if you've heard of the Resonance Sonomanometry method
| claimed by Esperto Medical https://esperto.health/ and how you
| think this compares to others.
|
| It seems like it might be an ultrasonic method? They claim no
| calibration needed, but I don't know if it is tolerant to
| movement and posture.
|
| I can also imagine this might be too power intensive to put in
| a smartwatch form factor. Maybe more of a bedside or clinical
| device...
|
| Disclaimer: I had past contact with some of their researchers
| in a different bioimaging domain. I don't know anything more
| about this venture than it says on the website.
| gausswho wrote:
| 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 wrote:
| 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 wrote:
| Try sticking it around your ankle and measuring while standing
| up. I get 250 mmHg systolic, easily
| daemonk wrote:
| 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 wrote:
| 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 wrote:
| 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 wrote:
| 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 wrote:
| 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
|
| 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!
| AStonesThrow wrote:
| It's the futility of trying to make two arbitrary numbers go
| down and covering up a mere symptom.
|
| Hypertension is correlated with a lot of issues, and it's easy
| to measure.
|
| It's also easy to keep formulating novel chemicals, so keep
| complaining about side effects, and your physician will be
| happy to keep spinning the Formulary Roulette Wheel.
| naveen99 wrote:
| It's complicated. You need blood pressure to live...
|
| Too low heart rate can also be a problem.
|
| talk to your cardiologist about your specifics.
|
| At the population level, the guidelines have backed off over
| the last 20 years. What's normal now used to be called high
| blood pressure.
| smeeth wrote:
| I'm not a doctor, but my understanding is that lower blood
| pressure can indeed lead to a higher heart rate under certain
| circumstances. For instance, people taking minoxidil for hair
| loss can experience lower blood pressure, which leads to higher
| heart rates and increased left ventricle thickness as a side
| effect.
|
| My suspicion is that this happens because the heart is trying
| to maintain a constant oxygen supply to the muscles. However,
| if blood pressure is lowered by improving factors like arterial
| flexibility, stroke volume (amount of blood per heartbeat),
| muscle oxygen efficiency, or oxygen content in the blood, the
| heart wouldn't need to pump faster.
| eig wrote:
| It's pretty normal for heart rate to increase with a drop in
| blood pressure. It's part of a normal reflex called the
| baroreceptor reflex that your body evolved to keep you alive.
|
| To answer your question, there have been an abundance of
| epidemiological studies showing that the drop in blood pressure
| is worth the slightly increased heart rate (assuming you've
| been diagnosed with hypertension). The main benefit is the drop
| in stroke risk, atherosclerosis, and kidney damage, even
| despite the fact that your heart has to beat faster.
| nisegami wrote:
| 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?
| danihh wrote:
| Great read.
|
| Side note: please fix your header. Makes the website appear so
| much less professional than the information it provides really
| is.
| brandonb wrote:
| 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 wrote:
| 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 wrote:
| 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 wrote:
| 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.
___________________________________________________________________
(page generated 2024-10-10 23:01 UTC)