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Biotech Science

Cheap Blood Clot Detection Device 103

Posted by kdawson
from the but-wear-your-helmet dept.
Gearoid_Murphy writes "The BBC details the news of a cheap handheld device to detect blood clots on the surface of the brain. The device uses infrared light to penetrate 3 cm into the body; light that has passed through clotted blood changes detectably. A doctor who is testing the device in India said, 'We found a 98% accuracy for showing blood clots or haematomas.'"
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Cheap Blood Clot Detection Device

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  • Woah.. (Score:4, Insightful)

    by Thyrteen (1084963) on Sunday April 15, 2007 @09:08PM (#18745883)
    I have a feeling that some surgeons will be sleeping alot better post-operation when they can monitor something like this more effectively.
    • Increasingly, actual technology is converging toward technology fantasized by Gene Roddenberry. This scanner for blood clots resembles the tricorder often used by Dr. McCoy or Mr. Spock.

      What's next? Warp drive [slashdot.org]?

      • by micknz (813240)

        Increasingly, actual technology is converging toward technology fantasized by Gene Roddenberry. This scanner for blood clots resembles the tricorder often used by Dr. McCoy or Mr. Spock.
        Hey, isn't it true sci-fi comes up with what science goes on to create?
        • by dwater (72834)
          > Hey, isn't it true sci-fi comes up with what science goes on to create?

          I don't think so, though I'm usually wrong. Engineers (try to) create things; scientists (try to) explain things.
        • Hey, isn't it true sci-fi comes up with what science goes on to create?
          I'll believe you when we're flying X-Wings around. Plenty of "true" scifi bends basic rules of the universe (speed of light for one) that scientists are (pretty darned) sure are more or less immutable.
      • Let's hope this thing works like McCoy's medical tricorder, rather than Dr. Beverly Crusher's.
        • by KDR_11k (778916)
          No, then it would always flash "He's dead, Jim!" if the patient is wearing a red shirt.
    • The article describes what seems to be an AC/DC coupled photoplethysmograph (PPG). However I am having a hard time believing that an infra-red signal can penetrate three centimeters through the skull, reflect off a blood clot, and be detected again. I recently worked at a company that made PPG devices that put an infra-red diode against the skin and then used a photo-detector to sense blood volume changes according to the amount of IR radiation that got reflected.

      The product that I worked with wa
  • by cgenman (325138) on Sunday April 15, 2007 @09:11PM (#18745903) Homepage
    Inevitably someone is going to say "Well yeah, that means 2% died. Rough lot of good that did them."

    Before that person is you, think of the 98% that lived. I bet they're pretty happy that their chances of detection and survival went way up. And if you were sitting on an operating table in rural India with a poorly underfunded doctor wondering what's going wrong with you, wouldn't you like to take those odds too?

    • by pytheron (443963) on Sunday April 15, 2007 @09:42PM (#18746101) Homepage
      To put statistics into perspective, you need to consider the following (for arguments sake).
      Say 98% lived with this new tech. What percentage lived without it ? Maybe 94%. You can't infer that the previous methods of detection/avoidance were mediocre just because the new method has a high success rate. The article certainly gives no comparisons.
      • by Repton (60818) on Sunday April 15, 2007 @10:05PM (#18746255) Homepage

        I'd also be interested in the false positive / false negative rates, and the overall rate of blood clots.

        Eg, suppose 1 in 10 patients develop blood clots under some circumstances. You could get a 90% accuracy by making a device that just reports "No clots" every time. If you're classifying 98% of clots as clots and 98% of nonclots as nonclots, over 1000 tests you'll have 98 blood clots correctly identified, 2 missed, and 18 nonclots misclassified as clots..

        (obviously I have no idea what the true rate of blood clots is)

        Of course, the engineers who made the device and the scientists who test it almost certainly know all this, so I'm not being particularly insightful. If they call it a breakthrough or think it will be useful, then they're probably right. We just can't tell either way from the article...

        ("Mainstream news article lacks useful details: film at 11!")

        • by jstott (212041)

          I'd also be interested in the false positive / false negative rates, ...

          Of course, the engineers who made the device and the scientists who test it almost certainly know all this, so I'm not being particularly insightful.

          I used to work in the field of diffuse optical tomography (DOT) and I'd like to know the false positive rate is too. It's a chronic problem in DOT, distinguishing between real blood pooling and generic signal clutter. 3cm is also very deep in the brain for DOT; we used to figure we c

        • by orkysoft (93727)
          That is called Bayesian statistics.

          P(B|A) = P(A|B)P(B) / ( P(A|B)P(B) + P(A|notB)P(notB) )

          P(B) = chance of a clot being present
          P(A|B) = chance of detecting a clot, given that a clot is present
          P(A|notB) = false positive
          P(notB) = 1 - P(B) = chance of there not being a clot

          The interesting value is P(B|A), which is the chance of there being a clot, given that one is detected.

          I haven't RTFA, so I don't know whether it tells whether the 98% accuracy mentioned is P(A|B) or P(B|A). If it's the former, I remain unco
      • Re: (Score:1, Informative)

        by Anonymous Coward
        TFA did say that the alternative - a CT scan - gives a better image. Point is it's anything but cheap or portable.

        "The infrascanner will never replace CT scans - but could be a highly useful new piece of medical technology."
    • Re: (Score:3, Informative)

      by Anonymous Coward
      In fact, they are using CTs to confirm the diagnosis...so the implication is that the hand held device is missing 2% of the cases that the CT is catching...at a great cost savings (what was that speech from fightclub about the recall formula?)...that might be the reason why the device isn't cleared for use in the states.
      • Re: (Score:2, Informative)

        by Anonymous Coward
        In developing a new technology, it's common to compare it's performance to the current 'gold standard'. Also, the device doesn't have to be perfect to be useful. It could be used as a first pass, and then a subsequent CT scan could be done on the patients that get a negative test result. It would be nice if the article gave the sensitivity and specificity so we would know what makes up its '98% accuracy'.
    • by fukitznukin (1088811) on Sunday April 15, 2007 @10:34PM (#18746437)
      The other way to look at it is to compare infrared to the current modalities. For example, MRI which provides very sophisticated images, picks up 96% of brain injuries including blood clots. However, this is a very expensive test and is time consuming. In my hospital, I can get a STAT MRI and a radiologist's report in 1-2 hours. If it's after hours, a team has to be called in to do the test and then you can add at least another 45 minutes. Infrared testing on the other hand is a bedside test that can be done very quickly and inexpensively. From a general perspective, 98% is not just adequate it is much better than most tests used in medicine. An EKG that is done for heart attacks for example can miss up to 50% and most people are relieved when they are told that the EKG is normal. 98% accuracy is almost unheard of in medical testing. The term accuracy includes the effects of false negatives and false positives so 98% accurate does not necessarily mean that 2% of the true positives are missed, the test could be picking up all the true positives but also some false positives (it overcalls the number of abnormal test results). Additionally, a test that is 98% accurate does not mean that 2% of the people die unless of course you are referring to a uniformally fatal disease of which blood clots on the brain do not belong. A subdural hematoma is one type of blood clot on the brain and its mortality is about 60%. Additionally, if you think about it, the 2% of blood clots that are going to be missed (let's say the miss rate is 2%) will be the smallest 2% of the blood clots and therefore the least lethal. Yes, size does matter when it comes to blood clots on the brain.
      • My original comment was made with broad generalizations in an attempt to counterbalance the lack of perspective on medical percentages that many people seem to exhibit. On the other hand, parent appears to actually know something, so please mod him / her up.
    • You don't understand the accuracy complaints, grasshopper, and proceed to bravely fight (maybe involuntarily) a complete straw-man that exists only in your imagination. Remember: just because you don't understand something, doesn't mean everyone else is an idiot. It just means you need to get some more data, and maybe engage the brains.

      The complaints about accuracy are for cases where the false positives are (A) a lot more than the new positives detected by the new method, and (B) the consequences for a fal
      • Re: (Score:2, Insightful)

        by cgenman (325138)
        Thank you for reading the article, and for your subsequent well-informed and enlightening response. I too know that people like chief neurosurgeon professor Alok Sharma are prone to exaggerating the effectiveness of medical procedures, in a manner very similar to that of a company hawking useless anti-terrorist gear. This can be true even when clinical trials have been outsourced to them and they, therefore, have no financial stake in the marketplace success or failure of the device. Your conclusion that
        • Can you even read, lemming, or are you in it just for the ego masturbation? No, seriously, I don't even see a need to try to be nice with a fucking retard.

          Can you even understand what an example is? No, I don't think so, and here you prove it fully. You're too stupid to even comprehend that "here's an example where X applies" does _not_ mean that this particular case is equivalent to X.

          Did you even see that the last paragraph explicitly says that "doctors aren't that stupid" to do the same mistakes politici
    • the device probably said they were all fine. 100% When 2% had blood clots or hematomas. That would make it 98% correct wouldn't it? Wouldn't that be great?
  • Company Website... (Score:4, Informative)

    by appleguru (1030562) on Sunday April 15, 2007 @09:20PM (#18745957) Homepage Journal
    http://www.infrascanner.com/ [infrascanner.com]

    Looks like they're based in PA, USA... But due to US regulations, they aren't allowed to test the device on patients in the US, and have outsourced such clinical testing to India.
    • Re: (Score:3, Insightful)

      by Reader X (906979)
      One wonders what other such testing is 'outsourced'...
      • by maxume (22995) on Sunday April 15, 2007 @09:58PM (#18746219)
        The bastards, sending a device they believe will work to hospitals with no alternative just because there is less government interference. I bet they kick puppies too.
        • by hazem (472289)
          he bastards, sending a device they believe will work to hospitals with no alternative just because there is less government interference.

          Ever see the movie Constant Gardener?
          • by maxume (22995)
            No I haven't, but looking it up, I don't see where a device that gives a doctor the ability to do something other than stand there and wonder about the patient relates to the movie in any way.

            I guess a doctor that was an enormous fool might end up trusting the device too much and forgo sending a patient that needed an MRI to a hospital where it was possible, but that's hardly a reason not to 'abuse' lax regulation to get some data about how the thing works.

            My reply was a snipe at the first poster, specifica
            • by alienmole (15522)

              the device is not dangerous(or at the very least, is incredibly unlikely to be dangerous)

              An infrared beam that penetrates 3 cm, through the skull? I could imagine that being dangerous. For example, it might have enough energy to damage tissue. I assume that they've tried to rule that out, but sometimes the messy reality doesn't match the theory.

              My reply was a snipe at the first poster, specifically because there really isn't any reason to bring in that particular rant in this thread;

              If you're not fam

              • You assume it penetrates 3cm because of high power levels. It's entirely possible for the skull to be transparent enough at the frequencies they are using that not much power is needed at all. Perhaps not much more than the amount received in those bands from natural sources.

                Though the specific power levels are not mentioned in TFA, the fact that it's a handheld device and requires a shroud lends credence to that idea.
              • by Reader X (906979)
                It doesn't necessarily reflect poorly on the company in this case, but it's an interesting related issue.

                Thank you. If I was more articulate, this is what I would have said.

                I was wondering whether this also was a standard practice for more dangerous medical inventions, such as pharmaceuticals, and whether the problem is really with 'excessive paperwork' costs, or with liability for product failure.
            • by hazem (472289)
              My apologies for being more complete. A major theme of the movie is a pharmaceutical company secretly testing a drug on Africans and quietly disposing of the patients who didn't survive. It was very well done, in a cinematic sense (it was gorgeous on the big screen), and I think it's one of the better adaptations of a Le Carre book.

              I agree with you. This would appear to have no harmful side effects, yet even in testing it, some patients could receive a benefit that they otherwise wouldn't. I don't see a
    • Re: (Score:2, Interesting)

      by fuego451 (958976)
      You really have to wonder what the FDA's motivation is for not allowing at least experimental use of this device in emergency settings, along with other accepted practices, to measure its effectiveness. Is there a genuine concern for the patients safety? The device certainly seems harmless enough.

      Ever the cynic, I would guess that the device and the procedure are relatively inexpensive and all parties involved are working out how best to monetize (god I hate that word).
      • by iminplaya (723125)
        It would attract lawyers like flies to dog poop.
      • The device certainly seems harmless enough.

        I don't know... If they can shine IR through a skull, bounce it off of a blood clot, and back through the skull, it's got to be fairly "bright". That's something like 2cm worth of bone that the light is shining through, and it's not like human skulls are made of crystal.
  • Damn! (Score:1, Funny)

    by schabot (941087)
    98% accuracy!! What the blood clot?!
  • In other news...

    Doctor Who spotted in India! /T
  • I wonder (Score:2, Funny)

    If this thing will be common I HATE MRIs but, I've been having massive headaches during and after sex. and yes I will wait, because I know the MRI tubes read my mind everytime go into one, and they won't let you bring a tin foil hat.
  • by Cathoderoytube (1088737) on Sunday April 15, 2007 @09:58PM (#18746221)
    I have to say as a blood clot sufferer this invention sounds great. For those of you who don't know the previous means for checking for blood clots was to drain out all the patients blood and let it settle, then the doctors would count the blood clots floating on the surface. On one occasion my doctor accidently dropped his pen in the vat, then he tried to fish it out. I went completely spare and told him if he expected to put that blood back in me after he'd been sloshing around in it he had another thing coming.
  • by Anonymous Coward on Sunday April 15, 2007 @10:42PM (#18746479)
    for your insensitive clots.
  • How it works (Score:5, Informative)

    by c_fel (927677) on Sunday April 15, 2007 @10:54PM (#18746549) Homepage
    Hemoglobin has a different absorption spectrum when it's oxygenated (oxyhemoglobin) or not (desoxyhemoglobin). An interesting characteristic of this spectrum is observed in the near-infrared part or light (700-850nm): http://omlc.ogi.edu/spectra/hemoglobin/index.html [ogi.edu]

    In the infrared part, oxyhemoglobin absorbs less light than desoxyhemoglobin ; it's the contrary in the red part. So if we shoot these near-infrared wavelengths (and some more, to get a good idea of the absorption spectrum) in the head and detect it somewhere else (around 5-6cm from the source), we can get information on the concentration and oxygen level of the hemoglobin in the middle of the emitter and the detector. If the hemoglobin is more present than somewhere else in the head, and it's less oxygenated than usually, we get a good idea that there's something wrong there.

    Other advantages : infrared light is non-ionizing, so it's absolutely no dangerous to use that kind of instrument continuously on a person until we are sure there's no problem.

    It's brilliant and I'm glad to see that kind of instrument emerging.
    • Re: (Score:3, Interesting)

      by nanosquid (1074949)
      infrared light is non-ionizing, so it's absolutely no dangerous to use that kind of instrument continuously on a person

      A kitchen broiler is also non-ionizing radiation, but I suspect using it "continuously" on someone's brain is not such a good idea.
      • I suspect if your brain is filling up with blood and the nearest CT scanner is either next town or at the end of a 2 hour waiting list then you'll be pretty damned glad to have a hand held diagnostic that can be used in seconds, even if there was a small risk either from it's method of operation or success rates.
        Everyone here seems to be looking at the products value in terms of the US medical industry which is a very different thing to the rest of the world. The US model is incredibly expensive but also h
        • by Ihlosi (895663)
          I suspect if your brain is filling up with blood and the nearest CT scanner is either next town or at the end of a 2 hour waiting list then you'll be pretty damned glad to have a hand held diagnostic that can be used in seconds



          The problem is - you'll still need to find an available OR with the corresponding OR team and a neurosurgeon. They're usually where the nearest CT scanner is and have similar waiting lists.

          • The problem is - you'll still need to find an available OR with the corresponding OR team and a neurosurgeon

            No, your missing the point - stop thinking US medicine practicies and facilities. I watched the BBC news item about this. A guy came in after a bike crash. At the side of the bed they scanned him, found a clot gave him a local, drilled a hole in his head and drained it - jobe done.
            They interviewed the poor sap just hours later 'How do you feel?' (shellshocked and quiet voice) 'Better'.

            • by Ihlosi (895663)
              At the side of the bed they scanned him, found a clot gave him a local, drilled a hole in his head and drained it - jobe done.



              Ouch.


              The device probably doesn't tell you whether the bleeding is epidural or subdural. If it's the former, you _might_ be able to get away with the simple procedure you describe, but if it's the latter, you better get the neurosurgeon, and fast.

              • >epidural or subdural
                Have to admit ignorence and not know the difference but if it helps, they drilled 3 holes, took out a triangular section of bone and flushed the area with a clear solution (saline?).
                • by Ihlosi (895663)
                  Have to admit ignorence and not know the difference

                  Well, sorry for slinging medical terms around then.

                  Epidural means "between the skull bone and the top layer of the brain". Draining a hematoma there is comparatively simple - drill a hole through the skull bone and be extremely careful not to go any farther than that.
                  Subdural means "between the outer, protective layer of the brain and the actual brain". Draining anything there means that you have to go through the outer layer of the brain, which is a more

        • Of course, the device is probably useful, and it's probably not dangeorus.

          I'm just saying that the argument "it's non-ionizing, therefore it's harmless" is stupid. Non-ionizing radiation can be very dangerous.
    • by nbritton (823086)

      It's brilliant.
      Luminously intelligent, or radiantly bright?
  • Cheap?! (Score:3, Funny)

    by quarrel (194077) on Sunday April 15, 2007 @11:09PM (#18746627)
    Oi!

    Who are you to call my blood clots cheap?!

  • False alarms? (Score:2, Insightful)

    by edsyc (1088833)
    Obviously a great development, but I wondered what the false alarm rate was. The device can detect 98% of blood clots, but how often does it say there is a blood clot when there actually isn't? False alarms could lead to costly, unnecessary surgeries that insurance (at least, insurance in the US) may not cover.
    • No, patients who fail the InfraScanner test could be given priority on the CT scanners for a more thorough examination. Which is better than the current system of giving priority to those who have good insurance.
  • by Anonymous Coward
    This will be most useful for those of us with heads 6cm wide.
  • Could you scan a whole head with a sufficiently bright torch in your mouth? Maybe you'd need that transparent skin mod from a while back too... It's be kind of strange having your eyeballs illuminated from the back :)

    I wonder if the same tech could also be used to detect DVT too? They could build it into the X-Ray machine at airports so that on the way in and out and a bell would ring if it found a blood clot in your legs (it would make sense to detect them on the way in too!)
    • by tuxicle (996538)
      Oh great, that's all we need, *another* airport scanner.

      Heh, my captcha says "comply"
  • FTA, Mihir Shah, from the company Infrascanner, said the American Navy has invested up to $1 million in the device.

    I wonder when there is such a breakthrough device in progress, isn't it unfair to have $1 million for a life saving cheap device research? I differ with people who sat CT/MRI scan is still to be carried out.So what? A CT/MRI scan minutes late can prove fatal and this is exactly this device is supposed to do , reduce this highly critical time gap to find out when actually to look for a scan as

  • by Anonymous Coward
    Death.
  • Couldn't he have just used his Sonic Screwdriver instead?

    Thanks, I'll be here all week.
  • I love this device. While it is only testing for clots and issues on the brain, I am wondering when something like this will be available to scan for things like a Pulmonary Embolism (which I had). The most annoying thing in the world was getting numerous ultra sounds to test for more clots in my legs... Hopefully someday, though, we will have something like a tricorder where we scan the body really quick and know everything that is going on... someday though... I am hoping... Please? lol.
  • Can detect blood cloths, pussy cloths, ras cloths and what not, so why do we need a device for such trivial job ?

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