Hopkins Study Finds Popular Blood Pressure App Wildly Inaccurate (jamanetwork.com) 50
An anonymous reader writes to point out a software review of the kind you can't generally find in an app store. A group from Johns Hopkins checked the accuracy of the Instant Blood Pressure app, which has sold more than 148,000 copies, and purports to measure blood pressure with just an iPhone -- no cuff required -- and found it wanting, to put it mildly. In the researcher's study, published in JAMA Internal Medicine, the app missed elevated blood pressures four out of five times.
Measure blood pressure with just an iPhone? (Score:1)
If there's no cuff or anything, how does it work? Magic?
Re:Measure blood pressure with just an iPhone? (Score:4, Informative)
The Instant Blood Pressure app (IBP; AuraLife) estimates blood pressure (BP) using a technique in which the top edge of the smartphone is placed on the left side of the chest while the individual places his or her right index finger over the smartphone’s camera.
image [cnbc.com]
I guess it's more accurate than rolling fair dice or plucking daisies.
Re: Measure blood pressure with just an iPhone? (Score:2)
http://i.imgur.com/9Scl3Ftl.jp... [imgur.com]
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XKCD (Score:3)
Is as accurate as TornadoGuard [xkcd.com]?
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That shows how to use it; doesn't explain how it (supposedly) works. One article claimed it could measure heart rate using the microphone, which doesn't sound right to me. I would assume that heart rate is actually measured by the camera, measuring the change in colour as blood pulses through whatever you've pressed it against - it's a simple and accurate way to measure heart rate.
I've no idea what holding it against your chest is supposed to do.
Arterial pressure propagation speed. (Score:2)
The thinge probably measures the time it takes for the arterial pressure spike from a heartbeat to propagate to the tip of your finger, and then uses some wild guessing to translate that into a blood pressure value. The technique kind of works, but only for measuring changes in blood pressure. You have to start with a regular (oscillometric or RR) blood pressure measurement and then track changes using the arterial pressure propagation del
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I did wonder if that might be it, but as you say it seems unlikely to work at all well.
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"how does it work? Magic?"
It uses The Force.
If its inaccuate its because you don't have enough Midiclorians in your blood...
Really! (Score:1)
And this surprises anyone (other than those 148,000 customers, of course) because...
Of course not (Score:1)
No one should trust a digital health app. Unless it's been validated in a clinical study, you shouldn't trust anything that's put out to run a smartphone.
Especially one like this. It uses the phone's accelerometer to measure your heart rate by putting it up against your chest and then measures the coloration of your fingertip by putting your finger over the camera lens. iPhone camera lenses and accelerometers were not designed for this use case, and this type of measurement has never been clinically stud
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"No one should trust a digital health app. Unless it's been validated in a clinical study, you shouldn't trust anything that's put out to run a smartphone."
So those penis enlargement Android apps don't really work? Asking for a friend.
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"No one should trust a digital health app. Unless it's been validated in a clinical study, you shouldn't trust anything ..."
You mean approved stuff like Lipobay and Vioxx?
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It uses the phone's accelerometer to measure your heart rate by putting it up against your chest and then measures the coloration of your fingertip by putting your finger over the camera lens.
Are you sure?
The heart rate apps I've seen use the fingertip colour to measure the heart rate. It's pretty accurate.
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Unless it's been validated in a clinical study....
Clinical studies can't be trusted, either, as they have usually been co-opted by financial interests.
Not much better than dedicated hardware (Score:1)
I remember when I wanted to take a more proactive approach to monitoring my BP, so I went out and bought one of those machines. Paid almost $100 for it, so wasn't exactly the cracker-jack model.
Plugged it in and performed several tests on both arms. Measurements swung so wildly that I ended up returning the damn thing the next day. Utterly pointless.
You want to measure your blood pressure accurately and consistently? Do it the old-fashioned way. Find a seasoned nurse with a good ear.
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$100? I've been using a $50 Walgreen wrist bp monitor for 3 years now that's been reliable and accurate. I just went to the doctor last Tuesday and before I went I checked my bp with my monitor and it was 127/84. 45 minutes later at the doctors office the nurse checked it and my bp was 126/79. Unless you've got circulatory problems in your arms, the monitors are decently accurate. When buying one, take it to the doctor's office and compare with the nurse's readings.
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What happens when your doctor's office doesn't use an old fashion cuff and instead use this one [amazon.com]? Every time I go in I have to position my arm in a different way. Sometimes it's stretched out, sometimes it's across by chest, once it was straight up. It's not really a surprise that my blood pressure always seems to be different (both significantly lower or higher) than what a traditional reading normally is for me.
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Every time I go in I have to position my arm in a different way. Sometimes it's stretched out, sometimes it's across by chest, once it was straight up. It's not really a surprise that my blood pressure always seems to be different
This is not the fault of the device, it is a problem in training and experience. If your health care professionals are as incompetent at the use of a standard blood pressure cuff as they are with the wrist cuff from Amazon, you'll get "significantly higher or lower" readings using the "traditional method", too.
"Measuring device at heart level" is the rule. Which medical professional do you go to that thinks that your wrist held straight up above your head is "at heart level"?
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I have taken my Omron to the doctor's office to compare to his measurement several times and it's been very close every time.
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Oh, who do you think you are kidding? If he is just average looking, but pays you any attention at all, that alone would get your blood pumping and you know it.
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All this time I have been waiting for the damn cuff to fall into the correct position of its own volition!
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Or make sure you actually know how to use one of those machines. You need to position the cuff very deliberately, make sure you are siting correctly, make sure the arm is at the proper level. There's more to it then it seems. I'm not say you specifically didn't use it correctly but in general people don't.
I'm not sure I've ever heard a more polite way of accusing me that I didn't RTFM, but thank you.
Oh, and by the way, yes, I did RTFM.
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Suppose I have an unseasoned nurse. What seasoning would you recommend? Thyme and Oregano? Maybe a little Cilantro?
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I remember when I wanted to take a more proactive approach to monitoring my BP, so I went out and bought one of those machines. Paid almost $100 for it, so wasn't exactly the cracker-jack model.
Plugged it in and performed several tests on both arms. Measurements swung so wildly that I ended up returning the damn thing the next day. Utterly pointless.
You want to measure your blood pressure accurately and consistently? Do it the old-fashioned way. Find a seasoned nurse with a good ear.
I have an older Omron and the readings it gives seem to be both consistent and broadly in line with the readings at my doctor's office. Sometimes getting different readings on different arms can be a sign of something wrong.
BP is difficult enough to measure as it is (Score:2, Insightful)
Even if you measure your BP with the standard cuff, it's difficult to measure. Patient beware. Your BP can be thrown off by a number of factors such as recent caffeine intake, urinating, not urinating (because you're anticipating the need for a sample), nerves known as "white coat hypertension", and probably some other things I don't know because I'm not a doctor.
If you have a high reading, I advise you to freak out like you're GOING TO DIE RIGHT NOW. Just kidding of course; but that's exactly the kind o
hype and fake all the way (Score:2)
so a badly coded app estimated blood pressure by superficial analysis of inaccurate measurements based on pseudo science.
and blood pressure in everyday conditions( as opposed to condition of a patient in controlled situation (eg hooked up in a bed) with certain other symptoms), even when measured correctly, tells us almost nothing by itself.
what a fake world!
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so a badly coded app estimated blood pressure by superficial analysis of inaccurate measurements based on pseudo science.
Oh, now, that's not fair. It could be an excellently coded app using superficial analysis of inaccurate measurements.
Well, color me surprised! (Score:2)
Class II Medical Device (Score:3)
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For entertainment purposes only!
I'm a little surprised (Score:2)
That they haven't had a visit from the FDA. Even with all their weasel-words, I don't see how they can get out of being considered a medical device by the FDA.
Considering the amount of crap my company goes through to comply with the relevant regs, I get really annoyed by people flaunting them and getting away with it.
120/80 ! (Score:2)
Just like blood oxygen saturation. It's 99% +/- 1% for 99% of all users.