• corry 13 hours 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).

    • throwup238 12 hours ago

      > 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.

      • KingMob an hour ago

        One of the things I wish had come out of the Quantified Self movement (which is now so mainstream, it wasn't even mentioned in this article), was a consensus awareness of how to mentally handle fluctuations when recording more data.

        We already knew that things like weight fluctuated in normal people (periods, hydration, meals, etc), but many of us are still defaulting to the inaccurate model of slowly-changing measurements recorded 1x/2x a year at the doctor's office.

        I'm sure people will get used to it, and many of the weight apps already wisely show averages to discourage fixating on individual measurements, but it feels like a missed opportunity.

        • outworlder 8 hours ago

          > 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.

          • throwup238 2 hours ago

            The data has to be collected under clinical conditions to control for confounding variables. People are notoriously bad at accurately recording their precise food intake which is probably the most important variable here. They need to do smaller controlled studies with provided diets. Large scale population studies with sensor data in the wild is going to be a trickier proposition that requires linking the sensors to the rest of the patients medical records which is a privacy mine field.

        • Aurornis 13 hours ago

          > 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.

          • KingMob an hour ago

            > Blood pressure readings are only useful in the context of stationary measurements under known conditions.

            This isn't fully true. For clinical reference to known "good" number ranges, then yes, you want to make the comparison as accurate as possible.

            Butm there's a lot of potential unlocked with more data.

            For example, we could discover that daily BP averages are more predictive than isolated doctor's office measurements. Imagine two people with equal BP measures at the doc's, but one has a more stressful job with higher average BP. We might reasonably expect them to have worse cardiac outcomes. Or consider the person who's anxious about docs and consistently shows higher numbers in the office than outside; we'd expect the reverse!

            Another factor might be examining the variance. This already has precedents, since we know there are things that heart rate variability (HRV) correlate with more strongly than heart rate itself.

            • nradov 12 hours ago

              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?

              • OJFord an hour ago

                IANAM, but if cardiac output is constant (say) and HR ↑ then you would expect BP ↓. I think that indicates good health too, that you don't need increased output, HR is just increasing to move oxygen around faster.

            • rootusrootus 13 hours ago

              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.

              • ljosifov 9 hours ago

                +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)

                • indoordin0saur 10 hours ago

                  Are the sensors already capable of it? Maybe someone could make a third party app for the watch

                • LorenPechtel 9 hours ago

                  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 9 hours ago

                    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.

                  • brandonb 13 hours ago

                    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 9 hours ago

                      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.

                    • Etheryte 13 hours 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?

                      • corry 9 hours ago

                        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.

                        • misstuned 9 hours ago

                          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.

                        • paulgerhardt 13 hours ago

                          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...

                          • m463 7 hours ago

                            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.

                            • avidiax 9 hours ago

                              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.

                              • sph 12 hours ago

                                > 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.

                                • corry 9 hours ago

                                  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.

                                  • sph 2 hours ago

                                    The cause is actually known: high amounts of fructose or sugar (which is 50% fructose) -> decrease in nitric oxide production in the liver -> high BP

                                    Like many things, it is diet related. It seems "unknown" because GPs are still lagging well behind modern dietary research and are often nothing more than pill pushers. Lowering your sugar and simple carb intake over the long term, and fixing potentially hidden metabolic syndrome (see skinny fat people with unhealthy livers) is how you reverse it.

                                  • AStonesThrow 11 hours ago

                                    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.

                                • mysterypie 12 hours 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.

                                  • brandonb 11 hours 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

                                    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!

                                    • CookieCrisp 11 hours 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

                                      • smeeth 11 hours ago

                                        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 10 hours ago

                                          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.

                                          • naveen99 11 hours ago

                                            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.

                                            • Aerroon 11 hours 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.

                                              • AStonesThrow 11 hours ago

                                                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.

                                              • bloopernova 14 hours ago
                                                • brandonb 13 hours 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.

                                                • kbrisso 14 hours 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.

                                                  • j_bum 2 hours ago

                                                    What are some examples of the non-pharmacological/lifestyle approaches you’ve taken?

                                                    • wil421 12 hours 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 11 hours 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.

                                                    • oidar 13 hours 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.

                                                      • wil421 12 hours 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/

                                                        • oidar 10 hours ago

                                                          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 11 hours ago

                                                          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.

                                                          • hombre_fatal 10 hours ago

                                                            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.

                                                            • oidar 10 hours ago

                                                              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.

                                                            • rootusrootus 12 hours ago

                                                              > HT dxs

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

                                                              • oidar 10 hours ago

                                                                yes

                                                              • candiddevmike 13 hours 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 10 hours 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.

                                                              • daemonk 12 hours 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.

                                                                • stewh_eng 13 hours 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_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.

                                                                  • saltcured 11 hours ago

                                                                    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.

                                                                    • utschig 13 hours ago

                                                                      Sotera Wireless

                                                                      • stewh_eng 13 hours ago

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

                                                                    • gausswho 13 hours 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 12 hours 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 12 hours ago

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

                                                                        • mikesabbagh 9 hours 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 9 hours 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.

                                                                          • loughnane 10 hours 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.

                                                                            • danihh 11 hours 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 10 hours 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.

                                                                              • nisegami 11 hours 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?