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I didn't reverse-engineer the protocol for my blood pressure monitor in 24 hours

james.belchamber.com

21–30 of 163 posts

Re: I didn't reverse-engineer the protocol for my blood pressure monitor in 24 hours

#21

Testing blood pressure after a shot seems weird. I have high blood pressure, managed with a low dose of medication. I've had plenty of advice from my PCP and other actual doctors on how to take blood pressure - how to sit, how long to sit still, how to position your arm, etc. It is remarkable how many medically-adjacent professionals are bad at this. My dentist starts my sessions with a blood pressure reading - theor…

> Testing blood pressure after a shot seems weird.

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 :)

Re: I didn't reverse-engineer the protocol for my blood pressure monitor in 24 hours

#22
post #2

Regarding white coat hypertension, the shot isn’t always necessary. Some people’s blood pressure just goes up from the stress of the clinical setting.

If you've got one of these machines at home it seems you really want to run it a couple of times. Often I find the first reading I get is quite alarming but then if I sit for a bit longer and run it another 1-2 times I get a very normal reading.

FWIW, some "smarter" machines (e.g., [0, 1]) support taking three readings with a minute pause in-between and then spit out a single reading.

[0] https://www.garmin.com/en-US/p/716808/ [1] https://www.withings.com/us/en/bpm-connect

Re: I didn't reverse-engineer the protocol for my blood pressure monitor in 24 hours

#23
post #13

I have three blood pressure cuffs They all give me different numbers, by a lot sometimes btw you think they ever clean those devices? you think healthy people go to pharmacies? I won't even touch the signature pen, imagine what's on that

I have a family member working in hospital setting. Electronics bairly survive a year from the amount of disinfectant they're exposed to. Everything is wiped so constantly that anything not made for the environment has its lettering stripped and rubber dissolved and cracked within short notice.

Re: I didn't reverse-engineer the protocol for my blood pressure monitor in 24 hours

#24
post #13

I have three blood pressure cuffs They all give me different numbers, by a lot sometimes btw you think they ever clean those devices? you think healthy people go to pharmacies? I won't even touch the signature pen, imagine what's on that

> btw you think they ever clean those devices?

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.

Re: I didn't reverse-engineer the protocol for my blood pressure monitor in 24 hours

#25
post #2

Regarding white coat hypertension, the shot isn’t always necessary. Some people’s blood pressure just goes up from the stress of the clinical setting.

If you've got one of these machines at home it seems you really want to run it a couple of times. Often I find the first reading I get is quite alarming but then if I sit for a bit longer and run it another 1-2 times I get a very normal reading.

Actually that is what my doctor told me to do, this seems standard procedure to measure twice every time with 1-2 minutes in between.

Re: I didn't reverse-engineer the protocol for my blood pressure monitor in 24 hours

#26

So I did something similar (well less cool), but as old Software devs start finding our bodies don’t work as well after a while we will see more and more of this sort of “taking control” https://mikado-aktiia.readthedocs.io/en/latest/

That's very cool. I wonder if sniffing the Bluetooth connection directly might be easier than reading the PDF (although not because it's easy). At least you have more than 24 hours to find out!

nRF Connect for Mobile[0] could be handy here.

https://www.nordicsemi.com/Products/Development-tools/nRF-Co...

Re: I didn't reverse-engineer the protocol for my blood pressure monitor in 24 hours

#27
post #2

Regarding white coat hypertension, the shot isn’t always necessary. Some people’s blood pressure just goes up from the stress of the clinical setting.

Yep. My heart-rate is normally pretty low (45bpm or so, 55 if I'm walking around), and my BP is on the high end of normal, but white-coat syndrome reliably brings it up to a fluttery 110bpm and 155/125 pressure. I was just in a wreck last week, so I got to see the before-and-after measurements from a few medical providers, and it's shocking how the act of talking to a new person in an unfamiliar environment spikes my BP even when I "know" that it's fine, and also how quickly it falls back down to normal.

Re: I didn't reverse-engineer the protocol for my blood pressure monitor in 24 hours

#28

> I tried feeding a lot of this into various Als (Kagi gives you access to a few with a nice interface) and I found that they mostly were stupid in ways that made me think "stupid in ways that made me think" is (IMO) a really good summary of how AI is useful, as well as its pitfalls.

yup, its a decent "Rubber duck" and an ok search engine.

Re: I didn't reverse-engineer the protocol for my blood pressure monitor in 24 hours

#29

So I did something similar (well less cool), but as old Software devs start finding our bodies don’t work as well after a while we will see more and more of this sort of “taking control” https://mikado-aktiia.readthedocs.io/en/latest/

That's very cool. I wonder if sniffing the Bluetooth connection directly might be easier than reading the PDF (although not because it's easy). At least you have more than 24 hours to find out!

I did wonder but I keep downloading to the app to “see how I am doing” Throughout the day so I would not be easily able to sniff it - and I assumed that as a highly engineered professional “medical device” it would of course be encrypted with unbreakable … oh it’s probably base64

Re: I didn't reverse-engineer the protocol for my blood pressure monitor in 24 hours

#30

> I tried feeding a lot of this into various Als (Kagi gives you access to a few with a nice interface) and I found that they mostly were stupid in ways that made me think "stupid in ways that made me think" is (IMO) a really good summary of how AI is useful, as well as its pitfalls.

yup, its a decent "Rubber duck" and an ok search engine.

https://en.wikipedia.org/wiki/Rubber_duck_debugging
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