Blood Pressure Monitor For Under $1

Medical equipment is not generally known for being inexpensive, with various imaging systems usually weighing in at over a million dollars, and even relatively simpler pieces of technology like digital thermometers, stethoscopes, and pulse oximeters coming in somewhere around $50. As the general pace of technological improvement continues on we expect marginal decreases in costs, but every now and then a revolutionary piece of technology will drop the cost of something like a blood pressure monitor by over an order of magnitude.

Typically a blood pressure monitor involves a cuff that pressurizes against a patient’s arm, and measures the physical pressure of the blood as the heart forces blood through the area restricted by the cuff. But there are some ways to measure blood pressure by proxy, instead of directly. This device, a small piece of plastic with a cost of less than a dollar, attaches to a smartphone near the camera sensor and flashlight. By pressing a finger onto the device, the smartphone uses the flashlight and the camera in tandem to measure subtle changes in the skin, which can be processed in an app to approximate blood pressure.

The developers of this technology note that it’s not a one-to-one substitute for a traditional blood pressure monitor, but it is extremely helpful for those who might not be able to afford a normal monitor and who might otherwise go undiagnosed for high blood pressure. Almost half of adults in the US alone have issues relating to blood pressure, so just getting information at all is the hurdle this device is attempting to overcome. And, we’ll count it as a win any time medical technology becomes more accessible, more inexpensive, or more open-source.

22 thoughts on “Blood Pressure Monitor For Under $1

  1. And the good news is, once the app records your blood pressure, it will store it on the cloud for insurance companies to track your health.

    (That’s why I stopped using blood pressure devices in stores when they required a login.)

        1. For citizens and permanent residents, yes. They have photo health-cards now, to prevent poor Americans from abusing the system.

          But hey, Americans have lying SCROTUSES on the SCOTUS that interpret the COTUS for the POTUS, and ROTUSES and SOTUSES of either HOTUS on the take, so they have that going for them.

  2. “it is extremely helpful for those who might not be able to afford a normal monitor”

    All you need is $1 of plastic! … And a couple hundred dollar smart phone.

    You can walk down to CVS, Target, etc. to purchase a proper blood pressure monitor for $30
    Amazon has multiple for under $20.

    Blood pressure monitors are already known for being inexpensive, including pulse oximeter too.

    Other than that, it’s an interesting idea.

      1. Anyone who can own a smartphone can buy a proper blood pressure monitor.

        Would be a weird place to live in where people can buy smartphones and monthly service subscriptions, but struggle afford the equivalent of a bag of groceries.

  3. Well, for a reality check, follow the posted link and read the comment by “Fatesrider.” Basically a dead-on assessment.
    There are so, so many factors affecting a blood pressure reading, and the peripheral extremeties are probably the worst possible locations to attempt to read.
    So, interesting concept, but honestly, pretty useless in the real world.

    1. Well if that’s the case – how on earth did this get published in Nature Scientific Reports?! Definitely points to a very poor peer review process! It’s true that a wildly inaccurate and unreliable measurement of an important homeostatic function like blood pressure could be considered worse than no measurement at all.

      1. Sometimes stuff slips through.

        Optical blood pressure monitors don’t measure absolute pressure, so the numbers are an educated guess. Smart watches that have this functionality already are either wildly inaccurate, or paired with other sensors for a more accurate estimate, and in this case the additional “sensor” is the applied pressure from a spring. Of course, the veins in your fingers react to many other things like heat, cold, mood… which are not controlled for.

        From the article: “Right now, the accuracy is at a screening level, not a diagnostic level.”

      2. Scientific Reports will publish anything as long as very basic guidance is met and the authors pay a publication fee. If the article says ‘this isn’t the same as cuff blood pressure’ or something technically correct, it’s ok. The journal doesn’t assess importance. Nature publishing group has many journals and publishes an extremely wide range of stuff, for profit.

        1. Scientific journals have ranking indexes that attempt to capture their “quality”. Scientific Reports has an SJR index of 0.97 while respected journals range from 10-100.

    2. “Peripheral blood pressures done at the wrist are off by more than 50%,”

      I can certainly confirm. My watch has an optical blood pressure gauge, and subsequent readings drift between 120/75 to 180/90 in a random fashion when taken one after another. Sometimes it drifts up, other times it goes down – you can get any number you want out of it just by clicking measure over and over.

      1. When I still used mine it was pretty consistent, but wrong. Back when I found out I got high blood pressure, it was the same time I got the watch. It’s under reading by a lot. Friend is a nurse, she checked with proper equipment and say it was 180/110 for her, 179/108 on a arm meter, and 140/90 on the wrist measurement. It’s not reliable. If this was a simple print you could download I would test it because I’m curious on how accurate it is. I got 4 different machines nowadays. They are dirt cheap in the store, cheapest was 12 euro’s. All work exactly the same, same results.

  4. Usually with this kind of thing, you’re not paying for the hardware. You’re paying for the calibration, and being designed in a way that it doesn’t need frequent re-calibration.

    In f-droid there’s a decade-old package that detects your pulse from video in the exact same way as this article. It only tries to detect pulse rate, and it’s only sometimes successful.

  5. As highlighted, its role today as a medical ‘diagnostic device’ it might need some refining, but given the size of a camera and led it could be easily integrated into something you already grip – like heart rate monitors on exercise bikes?

  6. “The developers of this technology note that it’s not a one-to-one substitute for a traditional blood pressure monitor, but it is extremely helpful for those who might not be able to afford a normal monitor and who might otherwise go undiagnosed for high blood pressure.”

    Considering that a half-decent blood pressure monitor with cuff costs about $20-$25, this is of course an *extremely* weak excuse.

    It’s just a gimmick. Will be bought by youngsters who will use it a few times to measure their own and their friend’s blood pressure. And then it will end up in a landfill polluting the environment.

    Your Blood Pressure is a valuable thing. $20 is not a big investment. Especially not if it gives you reliable readings, while this plastic gimmick can never do that.

    Your health is far too important to use some app that tries to correlate the data that it just read against some standard database of data measured for average people somewhere in the ’90’s, and then makes a guess about what your blood pressure probably is supposed to be.

    Useless and gambling with people’s health, possibly lulling them into a false sense of security. And of course the manufacturers don’t take any responsibility and didn’t even go through any certification.

    Also, the app is running on Android. Good luck getting your app on iOS, without having to add major disclaimers and warnings that the results cannot be relied on for a medical diagnosis.

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