Caltech Develops First Noninvasive Method to Continually Measure Blood Pressure
269 points
29 days ago
| 19 comments
| caltech.edu
| HN
coldcode
29 days ago
[-]
As a person who had a hypertensive crisis late last year, nothing boils my blood (yes, a pun, I am fine now) more than how people measure blood pressure incorrectly in doctors offices and even hospitals. There are many different things than can increase a BP measurement above the "baseline" including talking, moving around, not having rested but also just waking up, not being in a supported position, only a single value, etc. Most of the major health agencies (AMA,AHA,CDC, etc in the US) have recommendations on how to do it properly, but in medical situations like doctors offices and hospitals, these are rarely done as they take too much time. A single measurement is not sufficient and can result in misdiagnosis.

A more reliable way to measure a continuum would make a difference, but I imagine it would still require time to collect as BP is a dynamic value that changes with behavior, posture and activity.

reply
hereme888
29 days ago
[-]
I'm a resident physician and I deny having my BP taken in outpatient clinics.

The techniques used are ridiculously inappropriate:

"Ok, Mr. So-and-so, come with me." calls the nurse, as the pt who is irritated for having to wait 30 minutes quickly gets up to walk along unknown hallways, while rushing to finish a phone conversation, stressed and not knowing where to turn next..."Ok, now we're going to weigh you on this scale" while the pt thinks 'oh man, I've probably gained weight', followed by "ok, now we're going to measure your blood pressure." 'I don't want BP meds...let me try to relax...breathe slooowly...but I don't want the nurse to notice I may be trying to cheat this sudden examination.'

That's why the most appropriate way nowadays is to measure it at home, and keep a BP log.

reply
slaymaker1907
28 days ago
[-]
One thing that I think would dramatically improve the routine screening numbers at doctors' offices would be to try and take it after the patient has been sitting down for a few minutes waiting for the doctor after the other vitals have been taken. If I'm going to sit around for 15m+ anyways, why not use some of that time to let BP stabilize?
reply
hereme888
28 days ago
[-]
Because it's a practically impossible workflow: economics dictate that on duty your time should already be filled up doing something productive.

If anything, the usefulness of an office BP is to screen only people whose heads or hearts are about to blow up from a crazy high reading. Current guidelines now recommend people keep logs at home.

I manually recheck BPs myself if the readings are off the charts.

Robotics in the future could help the workflow though.

reply
dillydogg
28 days ago
[-]
One of my attendings has a running joke where he takes fresh interns in July and tells them "I will take you to <most expensive restaurant in my city> if you can take this patient's blood pressure correctly." He's been doing this for 30 years and no one has been treated to dinner yet. He's looking for the rest time, arm at heart level, everything.
reply
lostlogin
28 days ago
[-]
Correctly performed, it wont match every other BP test the patient has ever had done.
reply
thelittleone
29 days ago
[-]
People try to cheat BP tests? Because they dont want tp taks BP meds? Daaaang I'm trying to get my head around that. I guess I'm missing something because that sounds like an incredibly tangled way to be.
reply
basementcat
29 days ago
[-]
Pilots (and astronauts) lie to their doctors to avoid being grounded.

https://www.washingtonpost.com/politics/2023/08/27/faa-pilot...

reply
mkhpalm
28 days ago
[-]
You are supposed to be calm and relaxed for a proper blood pressure reading. Doctors have to find the resting baseline to diagnose hypertension.
reply
jerrysievert
28 days ago
[-]
as someone allergic to the bulk of blood pressure medications (currently taking some very old ones that don't affect me as much as the new ones that "don't have side effects"), hell yeah I'd cheat a blood pressure test if I could.

the difference between being a little dizzy and not being able to walk more than 10 feet without having to stop and throw up is huge.

reply
HackerThemAll
27 days ago
[-]
Not only the medical personnel is very often unable to properly measure the blood pressure, they also cannot properly take blood sample for potassium. They put tourniquet and order patients to pump their fist, so that the veins appear, but that cause muscles to release potassium into the bloodstream, causing elevated levels and misdiagnosis leading to incorrect treatment. I make people aware of that, and it should be widely spread so that doctors and nurses have the knowledge that they sometimes unwittingly cause harm.
reply
WWLink
28 days ago
[-]
> That's why the most appropriate way nowadays is to measure it at home, and keep a BP log.

"Oh yea those machines are junk and totally wrong"

And/or "WHY DO YOU TAKE YOUR OWN BLOOD PRESSURE?!" followed by accusations of being a hypochondriac.

Also the log is junk because I don't know how to properly take the blood pressure. Unlike the assistant who is also doing it wrong.

lolololol

reply
op00to
28 days ago
[-]
my blood pressure is significantly higher at the doctors office than home. I measure my blood pressure each morning at home. My doctor is happy to accept those readings.
reply
dgacmu
29 days ago
[-]
It's frustrating. I usually bike to the doctor's office, and every time I warn them that they're going to get a systolic 10 higher than if they'll wait until the end of the appointment. They don't wait. The tech-taken entry gets put in the EMR. The doctor takes my BP again at the end, says "oh, great" and that reading gets ignored. :p

As a sibling comment noted, I ended up deciding to just watch my BP at home every now and then. It turns out it's fine and it reduced my metaphorical blood pressure to monitor it myself.

reply
benmanns
29 days ago
[-]
However, as discovered during a family heart crisis, medical professionals will routinely ignore any kind of heart rate or blood pressure readings that you take at home. In my experience, it's not until they see the same measurement during the ($$$) ambulance ride that they take it seriously.
reply
WWLink
28 days ago
[-]
It really really depends on the office and their practices. I visited (and later brought my mom) to a cardiologist who is a terrible doctor, but his office does instruct you to log your blood pressure and then they review the logs. So at least they do that right.

What they do wrong: Queuing up 10 patients at a time, seeing like 60 a day, and then jumping from room to room like a kid with a bad case of ADHD. Dude told the assistant to give my mom 1 bp medicine, rushed out to another patient, and then rushed back 2 minutes later "no, give her this one instead!"

I can't trust that LOL. Our primary doctor got mad at me for taking my mom there and called the cardiologist a "f-ing a-hole" because he had a bad experience with his aunt going there LOL.

Honestly I ... I won't be going back, but I don't hate the dude. He's generally spot-on, even if he's rushed and his medicine advice is sketchy.

reply
ghaff
28 days ago
[-]
My primary care recommended taking my BP at home periodically and even wanted to calibrate my home system against the office system. I do tend to test higher in the doctor's office but I still periodically take it at home.
reply
WWLink
28 days ago
[-]
The good doctor offices do recommend all that. :)

To be fair, I'm guessing a lot of people really suck at it lol.

reply
grogenaut
28 days ago
[-]
I found that taking it at home helped a lot with white coat syndrome, I was more relaxed and more able to tell when I'd settled. I also just set a timer when walking and told the nurse "no not yet" when they tried to take my BP. They listened except the one nurse who insisted I was wrong and that I was 5'11" not 6'2" which was entered in by the urgent care the day before because people get shorter as they get older. You know, a day later, at 40, after being 6'2" since I was 18. no possible way she could be wrong, everyone else was. Also tried to mark me as an active smoker because I'd been in a resturant with smoking before, in the 90s and she had magically never been around smoke in her 50 years. The doctor corrected the smoker note but the height hung around in some SOT field even though the next 15 height measurements were 6'2" until I had an extra 10 minutes with a PA who went over all my records with me and corrected things.

I had trouble with 2 of the BPs drugs, one gave me head spins in the afternoon seated in my car sometimes, another gave me the dry cough (could feel a prickle in my thorat). My bp is actually high esp when I've had caffiene (what coder doesnt), move around, etc, but it's usually low pre-hyper tension. I also had it taken about 300 times in the last 6 months getting certified as an EMT. There's a LOT of variation in how the tools take the BP and just how close you're listening. I compared a manual cuff with one of the fancy automated ones and it's not that hard to hear your dystolic down 10 below what the automated reads. Same with systolic, you can hear it higher if you really listen before it starts sounding like a watch with another 10 spread, and you leave that cuff at 200 for 10 seconds and everyone's going to read higher and tense up more. I can feel my blood pressure surge any time an automated machine decides "nope I need to go higher on systolic" and it squeezes and I know I'm going to read high and have yet another conversation with the nurse and doctor. Just take it to 200 and come down stupid machine.

reply
nulbyte
29 days ago
[-]
As an adult with a congenital heart defect and white coat hypertension, I can relate. Once, a nurse took my blood pressure and immediately freaked out as I was sitting calmly on the exam table. She took it again in the same arm, then hurriedly took it in each of my other limbs before throwing her hands up.

Often, I would arrive at the cardiology office having made my way through downtown traffic to find a parking space and walk across the pedway. Then I'd find a seat as far away as possible from all the noisy children there to remind me that I should be dead. No wonder my BP is higher than usual. And you're the one freaking out?

I got so used to nurses tossing out every recommendation for measuring BP that I started taking it myself at home before visits just to prove the point. Eventually, as I grew older, my BP rose to a point where it actually needed to be addressed. I am now on medication. But I have yet to find a nurse anywhere that has taken time to follow even one recommendation for properly taking BP.

reply
pkaye
29 days ago
[-]
When I was a dialysis patient with frequent office visits, I've had the same experiences myself. Two things I've ended up doing is get to the hospital 30 minutes early, sit in a quiet area and relax till 10 minutes before the appt. Secondly I've found deep and slow breathing can improve your blood pressure a lot. The problem of white coat syndrome still remain though.
reply
teamspirit
29 days ago
[-]
I had hypertension for about 15 years and after quitting drinking and smoking no longer do. I still suffer from white cost hypertension regularly and frequently have to tell nurses to just press the button again - second time drops back to normal range with a drop of about 20/10.
reply
hn72774
29 days ago
[-]
I had it too. When I was under stress, sometimes I could hear my pulse in my ears like a whooshing sound.

I stopped drinking and my BP is now completely normal, and RHR is low 40's. Sleep is much better too.

reply
temporallobe
28 days ago
[-]
Are you serious? Your RHR is in the low 40s? Mine is typically 58-65 and I was told I have bradycardia!
reply
hn72774
28 days ago
[-]
Yes, and it was in the 50-60 range when I was drinking. My smartwatch use over a couple years has been informative.

It's a combination of genetics and athletics.

Edit: my smartwatch readings include sleep. Sitting upright at a table right now it's around 65

reply
layla5alive
28 days ago
[-]
My RHR is around 35. The rare occasions I get to go on vacation it dips into the high 20s while I'm sleeping. I haven't been on a real vacation in 2 years, though :/
reply
mikestew
28 days ago
[-]
Serious distance runner here: about five years ago while laid up in the hospital the alarm kept going off in the middle of the night on the HR monitor machine.

Nurse: “it goes off if your HR is too low.”

Me: “what’s it set to?”

Nurse: “39 BPM”

Me: “ yeah, you’re going to want to turn that down a few notches.”

Genetics play a role, too. Back in the day, one of the fastest road bike racers in WA state told me he’d never seen his resting HR below 60.

reply
lostlogin
28 days ago
[-]
We have a heart rate monitor at work that we use on 1-2 patients for day. It alarms at rate below 50BPM. At least once a week it's alarming at us.
reply
mkoryak
28 days ago
[-]
I stopped drinking and mine went up :p

Being sober is pretty stressful

reply
hn72774
27 days ago
[-]
It took me a good 10 days after quitting to start to feel "normal" and sleep without waking up drenched in sweat. Depending on intake and other factors it can take a while to fully heal. Months or longer.

Something I realized was that alcohol was actually causing my anxiety and depression, which was one of several things that led me to quitting. I paid compound interest on the short term relief.

reply
samstave
29 days ago
[-]
This would be the best use of the "AI Pin" fiasco of a device;

Create an AI pin that takes in all the activity associated with the BP monitoree, including telemtry for environment, movement, and diet. if I had a pin that did this (and recorded all audio for the day, and snapped pictures when I wanted and transcribed all audio via whisper and I had a full searchable day-runner...

Yay!

EDIT: The above desire is fully capable of a phone - except battery life...

I have a boatload of old phones. It would be interesting to just build a mini-build for an android phone to simply be a daily recorder. to capture audio/video only and run a slow app that will transcribe all audio to text on the device (even if it does so once its on lan, then it connects to an endpoint running locally on your docker desktop fast api to capture the audio that auto uploads as soon as on home lan. Sorts the files and pics and everything onto the NAS with simple txAI workflow to ffmpeg as needed.

reply
xattt
29 days ago
[-]
> A single measurement is not sufficient and can result in misdiagnosis.

During an acute care stay, a single blood pressure is a drop in the bucket. It averages out on the long term, and it’s not taken out of context of a clinical presentation.

I would take pressures manually, question unusual values, repeat on the spot and after some time had passed.

reply
HPsquared
29 days ago
[-]
I find doctors and nurses rush things too much in general. I guess they're paid flat-rate, like mechanics?
reply
ineedaj0b
29 days ago
[-]
there's just no time. we have to write down everything you tell us, we have to come off genial, make you sure you aren't lying about something or mistaken, and fix you.
reply
LightBug1
28 days ago
[-]
Thank you.
reply
barbazoo
29 days ago
[-]
They have a million patients. I bet no one on that moment thinks, oh I’m only paid $10.75 for this, I better rush this so I can earn more money.
reply
dillydogg
28 days ago
[-]
If you had to see as many patients as your doctors do, you would be rushing around too.
reply
m463
28 days ago
[-]
> not being in a supported position

does this mean your arm is not relaxed when measuring?

They always measure my blood pressure in a jury-rigged way resting on not an armrest, but some uncomfortable bracket of the blood pressure device.

reply
bamboozled
28 days ago
[-]
Yeah I was told I had high blood pressure, was about to be put on a bunch of medication and then I decided to get a second opinion. The hospital I went to gave me a 24 hour monitor and it came back I had perfectly fine blood pressure.

Turns was scared of doctors.

reply
blackeyeblitzar
29 days ago
[-]
Totally agree and I think the malpractice comes from laziness and a lack of interest in their patients. If they cared, they would do it correctly per the guidelines they hand out to patients themselves! By which I mean these: https://www.heart.org/en/news/2020/05/22/how-to-accurately-m...

It is especially bizarre to me when they don’t listen to patients and make medical decisions like deciding prescriptions and dosage amounts based on false readings.

reply
ineedaj0b
29 days ago
[-]
i don't think it matters too much. we don't want to take it right after you just exercised obviously, but even taking it once is indicative of things. 'i have white coat etc. i have nerves!' these are all things we don't mind seeing. all those those things connect.

using up time to double check blood pressure is so/so useful but generally a waste. a patient's labs tell much more, and are better to hedge suspicions against.

white coat hypertension at 320lbs!? alright sir we can check again if you like...

reply
dredmorbius
29 days ago
[-]
This approach has been tried before. Bill Softky describes a startup he'd worked for using a similar sound-transduction continuous non-invasive blood-pressure monitoring technique. It ... had problems:

Our non-invasive device was supposed to measure blood pressure just as accurately [as an arterial line], but without the cutting, using specially-sculpted sonic vibrations and fancy algorithmic analysis, which was my job. The overall challenge was like measuring the pressure inside a bottle without opening it. Our device worked fine, in that our algorithmically-estimated blood pressure moved up and down, beat to beat, in lockstep with the actual blood pressure. The problem was that our estimate also moved up and down at other times as well, say when the patient moved her fingers, rotated her arm, or took vaso-constricting drugs like nicotine. I spent most of a year understanding these problems, and understanding they couldn’t be solved before our funding ran out. That was when an old-timer taught me an important lesson of measurement: it’s fairly easy to calculate a signal which correlates with what you want to measure, the way our vibration-estimate correlated with actual blood pressure. It’s much harder, though, to calculate a signal which does NOT correlate with what you DON’T want to measure, like arm motion.

<https://www.linkedin.com/pulse/monster-monetization-bill-sof...>

I'd be exceedingly curious as to how the CalTech team have solved that non-correlation problem.

reply
Mistletoe
29 days ago
[-]
It’s just a blurb from a college PR team. As someone that came from academia, they don’t have to have solved any of that because these are generally pretty worthless. It can be as small as someone in a lab discovered how to do the smallest thing and the college wants to run with it to look good.
reply
dredmorbius
29 days ago
[-]
I'm aware. Which is why I'm pointing to someone who chased that "first" achievement for years, and has the scars to show for it.
reply
CamperBob2
28 days ago
[-]
There's a nicely-presented introductory paper: https://academic.oup.com/pnasnexus/article/3/7/pgae252/77177...
reply
mhb
29 days ago
[-]
Paper: https://academic.oup.com/pnasnexus/article/3/7/pgae252/77177...

They tested on the carotid artery. I don't know whether they're concerned with addressing issues of wearing this while active. It seems more likely that it will be used in a clinical setting.

reply
phkahler
29 days ago
[-]
The article mentions getting it down to an arm band or patch.
reply
Timothy055
29 days ago
[-]
Looking at the diagram I’d suspect they use accelerometer information from both the wrist watch and the upper arm mounted sensor to remove the effects of arm motion. At simplest it could only check when the arm is in a neutral position. But I’d expect they did something more complex/better than that.
reply
dredmorbius
29 days ago
[-]
As I understand Softky's work, it's not that the measurements varied predictably with movements, it's that they varied unpredictably.

I'm obviously distant from the project, but a team of SWEs spending years trying to make nondeterministic data deterministic suggests a fairly deep problem.

reply
CamperBob2
28 days ago
[-]
I guess it's not considered reasonable to keep your arm still when measuring BP, or to measure it only during intervals of minimal movement? Doesn't seem like a showstopper to me.

One of the key applications for this technology is during surgery, when (ideally) nothing is being moved.

reply
ryukoposting
29 days ago
[-]
Interesting. I recall working on some devices that implemented something called Pulse Arrival Time [1] which the biomeds on the team told me "isn't blood pressure, but it can be used for the same purposes."

Does this technique have an advantage over PAT? How true is the statement that "PAT can be used for the same purposes?"

[1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6912522/

reply
bjornsing
28 days ago
[-]
There’s a company called Biobeat that sells a patch you put on your chest for continuous 24-hour blood pressure measurement [1]. From what I’ve heard it’s in clinical use and works.

1. https://www.bio-beat.com/cuffless-blood-pressure-monitoring

reply
ck2
29 days ago
[-]
No they didn't invent the first way

The first way has been done in studies for years, maybe even a decade ago.

Earlobes.

I'll search for the papers later and link them.

https://scholar.google.com/scholar?q=earlobe+blood+pressure

https://www.todaysmedicaldevelopments.com/article/wearable-b...

I've always wanted a Garmin linked ear-cuff device that uses the earlobe for heartrate and blood pressure and then doubles as music playback or alerts from the watch. You could even do body temperature from the earlobe reliably.

reply
pkaye
29 days ago
[-]
This believe this blood pressure watch has been approved in a few European countries. It requires you to calibrate against the normal approach every month. I think they are trying to get it approved in the US by next year.

https://aktiia.com/

reply
ryeights
28 days ago
[-]
They’ve just received approval for a monitor that needs no calibration at all, although it’s not commercially available yet, and will probably take another half a decade to reach the US.

https://aktiia.com/uk/regulatory-approval-no-need-for-calibr...

Psst… the bracelet is available in the US if you use a UK freight forwarder, & download the app from the EU app store…

reply
benterix
28 days ago
[-]
I wonder how do you calibrate it in practice.
reply
pkaye
28 days ago
[-]
They include a blood pressure cuff with the watch.

https://aktiia.com/uk/blood-pressure-monitor

reply
hm-nah
29 days ago
[-]
Huge deal for humans moving forward. ~5-8yrs too late for me (2-5yrs for product dev, 3yrs since a hemorrhagic stroke that was likely caused by serious blood pressure).

I was 40 at the time and never measured my blood pressure (and certainly never when exercising). After the event I measured it all the time. During the 8th time of sitting in a chair, rolling up my sleeve, I thought, the Apple Watch has BP sensor, right?

That question sent me on a quest only to find that humans had not yet figured out a way to measure blood pressure on-the-go.

Congratulations on this effort!

reply
queuebert
29 days ago
[-]
This is quite an old problem. A quick search of PubMed yields 4834 results for "noninvasive blood pressure monitoring". Caltech has a weird definition of "first".

Edit: To clarify, plenty of things have been tried besides the cuff, but most patients who need something more sophisticated than that are already sick enough to be in the ICU, where an a-line can be placed. This is really a solution in search of a problem.

reply
Herodotus38
29 days ago
[-]
Aside from the home use, If this could be proven to be just as accurate as arterial lines this would be a huge benefit to patients in the ICU or undergoing major surgery where continuous blood pressure is needed. I hate putting in A-lines.
reply
dredmorbius
28 days ago
[-]
Yes, the concept is sold as a huge benefit in patient quality-of-life.

A-lines mean you can't just get up and move, or even roll over in bed. Non-invasive measures can simply be unclipped, or made fully mobile in the first place.

The problem is having a non-invasive method which works, which has been the sticking point until now.

reply
_qua
29 days ago
[-]
It’s one of my favorite procedures! To each their own I guess.
reply
kekeblom
29 days ago
[-]
Aktiia has a product on the market which supposedly already does this https://aktiia.com/uk/. It is based on an optical method though.
reply
trentnix
29 days ago
[-]
A year or two ago, I interviewed a developer who worked for one of the companies trying to build these types of optical blood pressure sensors. I have high blood pressure so I was keen to learn more. The gist of his message was that even in excellent conditions, it was very inaccurate.
reply
benterix
28 days ago
[-]
I wonder if things changed by now.
reply
ryeights
28 days ago
[-]
The Aktiia bracelet takes measurements automatically but not continuously. It produces about 1 measurement point every hour.
reply
spoonfeeder006
28 days ago
[-]
So basically resonance frequency of an artery doesn't depend on the artery's radius or wall thickness?

Or perhaps is that enough the case on a certain lower frequency band, where variations in those quantities are much smaller than the wavelength?

reply
amelius
29 days ago
[-]
> This measurement requires three parameters—a measurement of the artery's radius, the thickness of the artery's walls, and the tension or energy in the skin of the artery.

Ok, so now instead of 1 variable, there are 3?

reply
robomartin
29 days ago
[-]
I've been thinking a lot about continuos health parameter monitoring lately. For the last 100 days or so I have been running a personal health experiment and collecting multiple data points during the process. I guess some use the term "bio-hacking", not sure if it applies.

The experiment has included multiple fasting periods, with a maximum of 7 days as well as changing one variable at a time in categories such as diet and exercise. The results have been very interesting and I intend to continue on this path until at least the end of the year.

As part of the data collection I have been taking my blood pressure a minimum of twice a day, sometimes more. Also blood glucose, ketones and (consumer) EKG.

The first thing that jumped at me was the inaccuracy or variability of these measurements. I even got a Dexcom continuous glucose monitor. Interesting but useless for my purposes. The thing produced 20% error with respect to finger poke measurements. And, then again, when I got a calibration kit to check my finger poke meter, the calibration range is approximately +/- 18%. In other words, unless you hit extremes it feels like these measurements are almost useless. You can kind of tell you are going up or down, yet don't really know where you are.

The same, of course, has been true of blood pressure measurements. I went through three consumer machines. I can't say any of it is accurate because there are too many variables. I have run multiple experiments with regards to where and how to measure BP. All I can determine are relative changes by effectively measuring under as close to the same conditions as possible twice a day, morning and evening (both before meals).

During the last month or so I have been using a protocol I learned from one of Andrew Huberman's presentations (can't remember which one or I would post a link). I believe he was interviewing a researcher who explained the process they use during their studies. In simple terms, they take three measurements and then average. The first is after 15 minutes sitting, feet on the ground, back supported, no movement, no speaking, no activity. The second and third are at 5 minute intervals under the same conditions. In other words, the entire process takes at least 25 minutes.

After adopting this approach I have been seeing wildly different numbers with respect to the single measurement protocol I had been using for two months. In addition to that, the standard deviation of the computed values are much tighter now.

This experience, so far, has made me wonder about just how many people might be misdiagnosed and put on medication every year because of bad data. I can see the value in having more data, of course. Yet, continuous data is only good if it is accurate to within a reasonable margin.

reply
lostlogin
28 days ago
[-]
> how many people might be misdiagnosed and put on medication every year because of bad data

Another variable that causes this is the patient. They don't like the medication or don't take it properly but tell their prescriber that they are taking the medication correctly (age, culture, dementia etc). The prescriber then adjusts the dose.

reply
robomartin
28 days ago
[-]
Very true. My wife is a doctor. This is one of the issues that comes out most frequently during conversations about healthcare.
reply
ggm
28 days ago
[-]
I have reverse white coat hypertension: having a health professional care about me reduces my BP appreciably when they measure it. Placebos work very well on me, if delivered by an obvious competent authority like a nurse practitioner or GP.

I still take the hypertension meds: it's cheaper than paying somebody that highly trained to be nice to me.

reply
2-3-7-43-1807
28 days ago
[-]
> The new patented technique, called resonance sonomanometry, uses sound waves to gently stimulate resonance in an artery and then uses ultrasound imaging to measure the artery's resonance frequency, arriving at a true measurement of blood pressure.

That's invasive - gently or not.

reply
ruckfool
29 days ago
[-]
When will my apple watch support this ?
reply
patrickhogan1
28 days ago
[-]
So cool!
reply
anon115
29 days ago
[-]
meowdoesnt the apple watch do this already? or was that just heart rate?
reply
rrrix1
29 days ago
[-]
Just heart rate and psuedo "EKG."

BP monitoring requires a pressurized cuff which restricts (stops) arterial flow. The readings are the pressure of the cuff as it deflates when the blood starts flowing and when it can no longer be detected.

reply
jkid
29 days ago
[-]
https://bodyport.com/ (YCS15). Not continuous, but is non invasive. Given the variability of blood pressure throughout the day…
reply
oezi
29 days ago
[-]
This isn't measuring blood pressure, isn't it?
reply
barbazoo
29 days ago
[-]
And it’s not continuous either.
reply