[HN Gopher] NIST researchers use cellphone compass to measure gl...
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NIST researchers use cellphone compass to measure glucose
Author : geox
Score : 137 points
Date : 2024-04-06 00:18 UTC (22 hours ago)
(HTM) web link (www.nist.gov)
(TXT) w3m dump (www.nist.gov)
| lettergram wrote:
| Eh a lot of "these particles bonded with glucose - so now we can
| measure blood sugar levels" that's a massive stretch from where
| they are at.
|
| It's cool, but nothing close to what's described.
| rsfern wrote:
| I don't think the magnetic particles interact with the glucose,
| they're just a magnetic transducer basically. The main
| measurement device is a hydrogel that reacts with the glucose
| and swells, and they measure how far the magnetic particles
| move using a magnetometer to sense the change in field strength
| and back out the concentration (and pH)
|
| The linked Nature Comm paper seems pretty thorough, and they
| are reporting really high sensitivity (1000x what you'd need
| for typical blood glucose levels)
|
| https://doi.org/10.1038/s41467-024-47073-2
| lettergram wrote:
| Okay sure, I shortened it a bit. My point is the discovery
| wasn't directly related to the claims. Your description is
| more apt than the hyperbole in use cases. To accomplish what
| they describe would need a lot more research
| rsfern wrote:
| To be fair, they do call it a "proof of concept study" in
| the press release
| mlhpdx wrote:
| I wonder about the reference for the measurement, or precision
| versus accuracy. Still super interesting application of hybrid
| common and specialized tech.
| efriis wrote:
| Kept searching for an "April fools" with a 4/1 publication date
| to no avail
| YetAnotherNick wrote:
| My first thought as well. But unless they have went too
| overboard and published a nature paper[1] just for fun, it
| seems legit.
|
| [1]: https://www.nature.com/articles/s41467-024-47073-2
| teleforce wrote:
| Joking aside, you can actually use a wearable non-invasive
| electromagnetic sensor device to accurately measure glucose level
| [1].
|
| [1] Meet the inventor: Professor Adrian Porch from Cardiff
| University:
|
| https://www.med-technews.com/medtech-insights/latest-medtech...
| Dwedit wrote:
| Type-1 diabetics have no working pancreas, and need something
| that meets the highest standards before it gets approved for
| use. Is this product up to those standards?
| manmal wrote:
| I think a MARD of <= 14 would be required to be useful.
| ijustlovemath wrote:
| 10% is what you really need to have excellent control
| manmal wrote:
| I'm not aware of any accurate noninvasive device on the market.
| Recently there's been an influx of fake watches that claim to
| do so, but they mostly make up the values. The linked article
| mentions that research is ongoing - can you point me where such
| a device is being sold?
| teleforce wrote:
| I'm not sure if the device is currently being sold since they
| need to get the approval for any medical devices. For results
| and accuracy please check their papers from several years
| back [1], [2]. I think may be you are right, for transparency
| they need to release all the accuracy, sensitivity and
| specificity of the non-invasive glucose detection device, and
| from the publication title it seems only sensitivity results
| are currently being published. Personally I have one patent
| pending on non invasive ECG anomaly detection that cover both
| arrhythmia and ischemia with comprehensive 99% accuracy,
| sensitivity and specificity, and high accuracy of non
| invasive detection technique is certainly achievable.
|
| [1] Microwave Noninvasive Blood Glucose Monitoring Sensor:
| Penetration Depth and Sensitivity Analysis (2018)
|
| https://ieeexplore.ieee.org/document/8428850
|
| [2] Microwave noninvasive blood glucose monitoring sensor:
| Human clinical trial results (2017):
|
| https://ieeexplore.ieee.org/document/8058721
| manmal wrote:
| In order to bring a CGM to market, in many areas of the
| world you need to perform a number of clinical trials, and
| a certain MARD upper bound has to be demonstrated. Also,
| during development certain ISO/IEC standards must be
| followed, which cover continuous medical & information risk
| assessment and mitigation. It's usually a process of up to
| a few years even after you have a strong belief that it
| performs well enough.
| rrrrrrrrrrrryan wrote:
| > accurately
|
| Not nearly accurate enough to make insulin dosing decisions,
| which is all diabetics care about.
|
| For the foreseeable future, non-invasive glucose monitors will
| be like the scales that measure your body fat through
| electrical impulses. A neat toy, but not actually useful for
| medical purposes.
| tzs wrote:
| > Not nearly accurate enough to make insulin dosing
| decisions, which is all diabetics care about
|
| It might be all type-1 diabetics care about, but for the
| 90-95% of diabetics that are type-2 much less accuracy is
| needed.
| rrrrrrrrrrrryan wrote:
| Well, 25% of those type-2 diabetics take insulin, but yes,
| those that don't take insulin may be able to derive _some_
| value from a less accurate sensor.
|
| I just don't know why you'd choose the less accurate thing
| when it's your health.
|
| I think the non-invasive stuff makes the most sense for
| people who don't have diabetes _yet_. Nothing will be
| covered by insurance for them and the non-invasive tech
| might be cheaper, and it can nudge them to make healthier
| eating decisions.
| szundi wrote:
| The fact that Apple has not gone for it yet tells a lot about
| the actual usability of such devices imho.
| peter_retief wrote:
| I have been playing around with various sensors on the skin, one
| that is interesting is IR absorption which can read glucose as
| well. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5772583/ I got
| some interesting results with combining sensors and using ML to
| identify different labels, even managed to identify left and
| write arms?!? I made a few notes here
| https://nix64bit.com/identification.html
| naikrovek wrote:
| > left and write arms
|
| How do people make this mistake
| peter_retief wrote:
| They don't read what they right i guess :=)
| bluenose69 wrote:
| I was surprised to read "Employing this strategy, the researchers
| measured glucose concentrations as small as a few millionths of a
| mole" in an article published on an NIST website.
|
| I fear that they, like so many organizations, must employ non-
| experts to interview experts and write stories. But getting the
| unit of concentration wrong? (Later in the sentence they do note
| that moles refer to quantity, not concentrations, so the whole
| sentence is self-contradictory.)
|
| This problem is so common I think it might make sense to suggest
| a common solution. Perhaps an organization specializing in X
| ought to hire one member of the writing team who has a degree in
| X, to look over material before it goes out to the world. Or at
| least pay one of the experts on a per-case basis, say a day of
| salary for a half hour of work, to go over material before it is
| published.
| ramon156 wrote:
| I honestly just hope it's satire, it almost feels on purpose
| ramon156 wrote:
| I honestly just hope it's satire, it almost feels on purpose
| WhyUVoteGarbage wrote:
| Technical correctness and public relations are natural enemies.
| The original material comes from scientists who know what they
| are doing, but they aren't allowed to write their own press
| releases. For scientific papers, the scientists are already
| encumbered by layers of review that make it difficult to meet
| deadlines for publishing.
| admissionsguy wrote:
| I instinctively read it as referring to molar concentration. It
| is actually common in chemistry to say "10-mole solution",
| which means 10 moles per litre. The per litre part is implicit,
| which confused me greatly during undergrad classes. The actual
| unit of 1 mol/L is called a molar.
| bluenose69 wrote:
| Yup, I knew a postdoc once who didn't like to say litre; the
| first time I first heard him say "mole per dm cubed" I didn't
| know what he meant. (He also had an accent.)
| ijustlovemath wrote:
| These sensors might work well in the lab, but people have been
| trying various spectroscopy based noninvasive sensing techniques
| for the better part of 15 years, with limited success.
|
| The problem is not that you can get a nicely correlated signal
| when holding a stationary phone against a stationary well of
| known concentration, the problem is how does your sensor perform
| when:
|
| 1. You're exercising (sweat getting between the sensor and the
| skin)
|
| 2. You're on vasoconstrictors (smoking or blood pressure
| medications)
|
| 3. You're taking medication that "looks" similar to glucose (in
| electrochemical sensors that's ~~ibuprofen~~ acetaminophen, but
| the number of magnetic analogues, especially in the presence of
| interference, is surely greater)
|
| 4. You have low perfusion
|
| 5. You're sleeping on/compressing the sensor. This changes how
| the blood flows, and needs to be accounted for or you'll risk
| reading a false low value.
|
| These are just a handful of the problems that modern CGMs face,
| and only a few of them have working solutions.
| tzs wrote:
| The article is not about a noninvasive sensing technique.
| ijustlovemath wrote:
| Magnetometers are noninvasive! They don't penetrate the skin
| adrian_b wrote:
| That's not how it is used here.
|
| The sample liquid containing glucose, e.g. wine or possibly
| blood (the sample might need to be diluted first with pure
| water) is put on a gel that has volume changes depending on
| the amount of glucose.
|
| The volume changes are detected magnetically because the
| gel is coated with a ferromagnetic material.
|
| If this were used for blood glucose, the blood would have
| to be extracted first by traditional means.
|
| This does not seem to be the intended use, because the
| already existing invasive devices are more convenient.
|
| The intended use appears to be for testing food using a
| device that contains the gel and to which you attach the
| smartphone in order to read the results.
| ijustlovemath wrote:
| Yes, I understand how they conducted the experiment!
| Because this would not be place under the skin, it still
| constitutes a noninvasive sensing technique
| refulgentis wrote:
| Distinction without a difference, your lead comment is a
| list of common issues for something that is orthogonal to
| the article. I appreciate it regardless but some humility
| is in order :) not being strictly on topic is fine, it's
| still interesting. But I don't think arguing they're the
| same thing repeatedly down thread is kind.
| adrian_b wrote:
| If this were used for blood, it would be invasive,
| because the blood must be extracted with needles, exactly
| like in the current kits for measuring blood glucose.
|
| The gel holder would substitute the sensitive strips that
| are used in such glucose measurement kits and the
| smartphone would replace the electronic reader that
| displays the results.
|
| Nothing would change about the invasiveness of having to
| pierce the skin with needles, to extract blood.
|
| There exist experimental devices for non-invasive
| measurement of the blood glucose, whose purpose is to
| avoid the use of piercing needles, but this new glucose
| sensor has nothing to do with those.
|
| This new glucose sensor is for other uses and its
| advantage is that it no longer needs a special expensive
| electronic device for reading the sensor output, but a
| standard smartphone is good enough.
| Paul-Craft wrote:
| > 3. You're taking medication that "looks" similar to glucose
| (in electrochemical sensors that's ibuprofen, but the number of
| magnetic analogues, especially in the presence of interference,
| is surely greater)
|
| Huh, I never knew this. Does this mean taking ibuprofen can
| give you an elevated glucose reading on a blood test?
| ijustlovemath wrote:
| I misspoke, it's actually acetaminophen (I'm always confusing
| the two!):
| https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5950984/
|
| But yes, presence of acetaminophen with a naive
| electrochemical sensir will cause false high readings, which
| are VERY dangerous!
|
| The latest generation of sensors have fixed this problem, but
| with any new sensing tech, you need to make sure you're
| learning from the mistakes of the past. With a new sensing
| paradigm, you won't necessarily have problems with the _same_
| drugs, but knowing that this kind of constructive
| interference is a potential problem will help you design a
| more robust system.
| jfengel wrote:
| Just a note about false readings. A diabetic with high
| glucose is deeply uncomfortable, and will suffer long term
| damage, but is not in immediate peril.
|
| The bigger danger is being low, which will lead to
| unconsciousness, coma, and death.
|
| Insulin brings down blood glucose. Getting insulin when not
| needed can be deadly. (It's a favorite of murder mystery
| writers.) False highs are more of a risk than false lows.
|
| Which means you may need to administer sugar to a diabetic
| in an emergency. But unless you're a medical professional
| you will never need to give them insulin.
| ijustlovemath wrote:
| Absolutely, the danger of a false high is that you dose
| insulin to correct and end up pushing yourself into a
| dangerous hypoglycemic state. That's why acetaminophen
| interference is so important to deal with! And while it's
| true that running a bit high (250-350mg/dL) isn't an
| immediate risk, DKA is still a possibility once you
| breach the 300s, and that will land you in the hospital.
| bilsbie wrote:
| I'm more interested in measuring insulin than glucose.
| evanjrowley wrote:
| >Similarly, the team's study suggests that a cellphone
| magnetometer can measure pH levels with the same sensitivity as a
| thousand-dollar benchtop meter but at a fraction of the cost. A
| home-brewer or a baker could use the magnetometer to quickly test
| the pH of various liquids to perfect their craft, and an
| environmental scientist could measure the pH of ground water
| samples on-site with higher accuracy than a litmus test strip
| could provide.
|
| To determine if my body is burning ketones on a ketogenic diet, I
| used to have to pee on pH-sentitive keto test strips. Sounds like
| in the future I'll be peeing on my phone instead.
| ricardobeat wrote:
| Doesn't a electronic PH meter work for this purpose (hopefully
| not shared with the kitchen)?
| ricardobeat wrote:
| This doesn't look like the breakthrough the headline suggests, at
| least for glucose monitoring.
|
| They created a material that contracts/expands depending on
| measurement levels, and that can be detected by the magnetometer.
| But the sample needs to be deposited in it.
|
| This is _not_ a non-invasive glucose monitoring solution, and
| current under-skin devices will remain a lot more convenient.
|
| A magnetometer costs $1-$5, plus a couple dollars for a
| microcontroller, what will likely happen is that this will result
| in a new breed of devices that offer laboratory precision at very
| low cost. The phone part is irrelevant.
| jfengel wrote:
| Of all the things they described as possible, measuring glucose
| is the least interesting, since we already have a better tech
| for that.
|
| They have a number of other potential applications, and it's
| rather clever and surprising. They could have led with any of
| those.
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