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.
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.
"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
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.
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.
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.
I stopped drinking and my BP is now completely normal, and RHR is low 40's. Sleep is much better too.
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.
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.
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.
Turns was scared of doctors.
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.
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...
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.
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.
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.
One of the key applications for this technology is during surgery, when (ideally) nothing is being moved.
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.bio-beat.com/cuffless-blood-pressure-monitoring
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.
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…
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!
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.
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.
Or perhaps is that enough the case on a certain lower frequency band, where variations in those quantities are much smaller than the wavelength?
Ok, so now instead of 1 variable, there are 3?
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.
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.
I still take the hypertension meds: it's cheaper than paying somebody that highly trained to be nice to me.
That's invasive - gently or not.
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.
