I Didn't Reverse-Engineer the Protocol for My Blood Pressure Monitor in 24 Hours

I have to take daily BP measurements during titration for ADHD medication. (Using an _A&D UA-611 Plus_ machine at home.)

I can put the cuff on my arm and sit at my desk for 20 minutes to be nicely rested and calm, and then take 5 different measurements with a few minutes between each one. They'll vary quite wildly (anything from, say, 115/75 to 135/90) despite not moving between measurements or having any reason to be more or less agitated. I generally just ignore the low/high outliers and average the others. There's no pattern either, sometimes the outliers are first, sometimes last.

Also it's not just the monitor I have at home, the same is true of a probably more trustworthy machine in a clinical setting. I mentioned this to my doctor when I last visited and we saw the same thing with multiple measurements using a more sophisticated machine at the clinic.

It really amazes me how people whose job it is to take blood pressure don’t recognize the stress situations that people are in might result in abnormal readings.

It also never helps to explain that this has happened many times before and that I have a reasonably high quality BP measurement device at home (most recently the exact same Braun model) that gives me decent measurements when I'm at rest/relaxed. They just look at me like I'm an idiot. How could a civilian conceivably perform such a complex measurement?

Then I get the predictably insanely high measurement and they look satisfied. Gotcha!

Please bring on the AI doctors.

This prompted me to do some research, and it turns out there's very strict guidelines for how to 'accurately' measure blood pressure, almost none of which were followed by most specialists. There's a laundry list of things that can each increase your blood pressure by 10-15mmHg (eg. drinking water, sitting cross legged, recent physical exercise, not sitting with the right posture, not sitting for at least 15 minutes).

Given this lackadaisical approach to measurement, I seriously question the diagnostic validity of blood pressure tests 'in the wild'.

Doctor ends up telling him that he was hoping it was just the attractive nurse, but no. He'd be starting medication today.

It’s not the cuff position as I used multiple positions, cuffs, and sensors. All 140/90. Plus I feel it.

It’s wild. My BP/HR fluctuates alot outside of clinical, but inside clinical it drops.

It took me a minute to understand (and neither of us think this is 100% true) but it's both funny and a good point.

At least you have more than 24 hours to find out!

FWIW the latest version of the app does export the previous day's averages to Apple Health (only when you open the app, mind, which can make it look like there's missing data.) I use BPExtract to read the PDF and export every reading to Apple Health but I'll definitely be giving your stuff a go as well (because automation >> manual every time.)

Although I think you need to be quite critical to have such a mindset, and assume you are wrong rather than right.

I was at the Dr last week and my first BP reading was 154/95, a second reading a few minutes later was 141/89. The doctor asked for one more reading before I left.

The medical assistant gave me my vaccines and then took my BP, 130/81 right after a Hep B and COVID vaccine. I told the tech that needles didn’t bother me at all, she believed me after she saw my blood pressure :)

They wanted me to start on all sorts of medications immediately.

The second-last time, they got a reading of 220/130, and were going to get an ambulance to take me into hospital immediately.

Er, hang on a minute, folks.

That's beyond "hypertension crisis" and well into "incompatible with life" levels. That's the kind of pressure I see in hydraulic servo feedback channels, not living things.

They grudgingly agreed that someone with high blood pressure probably ought not to be making as much sense as I was, although what would I know about it, they're the professionals, etc etc.

The next time I noticed the automatic blood pressure cuff had a fresh new calibration sticker on it.

130/90. Not bad, for a reading taken at the doctor's surgery.

I wonder how many people are on medication they just plain don't need because of a plainly faulty sphyg though?

Maybe? Do they clean the shelves? Arm-to-arm contact isn't exactly a big threat.

> you think healthy people go to pharmacies?

Yes. Of course. Those free blood pressure machines are generally found in drug stores that have a small pharmacy section. The vast majority of people there are there because they're shopping. There are probably more people who come in to buy mascara than people who come in because they're sick. If you're sick, someone else goes to the pharmacy for you.

These have been around since I last used WINE in anger on macOS. Basically think of it as a container for running an app in WINE with all the settings predefined for best compatibility. The homepage doesn’t really highlight this but you can look through the docs for more information.

If you've heard of Lutris, Bottles is essentially the same thing, but aimed at general software instead of only focusing on games

0-4 month 4-7 year 8-10 hour 11-15 day 22-23 hour 24-29 flags 30-31 year

I'd be wary of the sugars in bananas and orange juice.

Last week, I met an experienced top swimmer who doesn't use any devices, he just listens to his own heartbeat.

I worked next to another engineer in the early eighties who was working on a different project. At tea break time we got into the habit of sitting opposite each other and explaining the problems we were having. Neither of us put much, if any, effort into trying to solve the other's problems because it often turned out that simply attempting to formulate the problem in a way that would make sense to the other party was enough to reveal the answer or at least a promising idea to try.

> A few times I thought they had "cracked the case" but actually they just made me waste time.

Despite trying various models and services for years now, I've come to the conclusion that the current iteration of AI services hurts more than it helps. I spend more time prompting, reading pages of babble, and trying to find signal in the noise that I would just chilling out and thinking through the problem.

The technology is neat but not productive.

But when you look at everyone's experience with blood pressure, it actually seems like it's BP that's just not reliable and a better type of measurement would be helpful.