Cheap Blood Clot Detection Device 103
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.'"
Woah.. (Score:4, Insightful)
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And provides a lot more information than this handheld gadget can. Given a choice, I'd opt for some real imaging rather than a high-tech studfinder.
Re:Woah.. (Score:5, Insightful)
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Re:Woah.. (Score:4, Interesting)
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From Wiki: http://en.wikipedia.org/wiki/Maggot_therapy [wikipedia.org]
The current use of maggot therapy is estimated to involve over 3,000 doctors, clinics, and hospitals in over 20 countries. In 2003, approximately 30,000 treatments were administered to an estimated 6,000 to 10,000 patients.
As for leaches, the FDA allowed there use (as a medical device) in 2004: http://www.msnbc.msn.com/id/5319129/ [msn.com]. Which goes to show, everything old is new, and ever
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From National Geographic:
Only a few species of fly larvae, primarily blowflies, are suitable for such duty. Five to ten maggots are placed on each square centimeter (0.2 square inch) of a wound, which is then covered with a protective dressing that allows the maggots to breath. For the next 48 to 72 hours, the maggots dissolve dead tissue by secreting digestive juices and then ingesting the liquefied tissue and bacteria
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If I remember the wiki article, the FDA has certain rules regarding how the maggots are raised and which type are used. It looks like the FDA approved their use (as a medical device) in 2004, but
Errr... (Score:5, Informative)
Aside from the fact that a lot of the time, we're more worried about post-op *bleeding* (which we'd see on CT) than simple clotting, I'm not sure how you'd tell appropriate clotting from dangerous clot, *except* through monitoring symptoms. Its not the clots after surgery that are dangerous, but when the clots are in areas that suffocate healthy tissue (ischemia).
And a CT looking for new infarct would be useless. An MRI might help, but not a CT.
And, yes, IAAD.
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"Remember the impact of patient dose.
CT brain + CT chest + CD abdomen + CT pelvis = 1250 chest X-rays"
I work in stroke ultrasound, and our patients often have at least two CTs during their stay. That's a *lot* of x-ray energy.
(CTs tend to have their output parameters stamped on them... our machine is generally set between 25 and 45 kW, with about a 50% duty cycle. That's a heck of
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That's a fairly unfair comparison, since I believe that it factors in the radiation sensitivity of various areas of the body. Head and chest aren't very sensitive, but abdomen (especially the intestine) and pelvis (lots of bone marrow there) are.
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Also, if I remember correctly, they sometimes inject stuff into patients taking CT brain to make those CT scans more sensitive. That would level the difference between CT brain and CT abdomen some, esp. if that injection is itself radioactive.
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It's even less than that. The abdomen and the pelvis are much, much more radiation-sensitive than the chest or the head.
Also, if I remember correctly, they sometimes inject stuff into patients taking CT brain to make those CT scans more sensitive. That would level the difference between CT brain and CT abdomen some, esp. if that injection is itself radioactive.
Um, sorry, but you've go things mixed up there
Re:Woah.. (Score:4, Insightful)
This will help determine if patients need immediate attention.
As long as the false positive rates aren't high and this device is sensitive enough to detect the common cases, it will be useful.
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I can see this tech being used some day to detect clots in legs, arms, etc.
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Was that in the US ? If so, then maybe the insurance companies over there should think about sending the less urgent cases on an all-expenses-paid vacation to Europe that includes the MRI scan. It'd save them a whole lot of money. Maybe they can even include a business class flight, too.
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Sorry, I was talking rubbish, it was an MRI scan. Great fun though. Loved the noises it makes - would be a great industrial style CD release. The operator told me it reminded her of Einstürzende Neubauten which sounded a fair comparison.
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It was more exciting 23 years ago, when being able to have a look at the room-filling computer and the operating panel was reward enough for a loud and boring three-and-a-half hours long procedure.
I asked how much memory the computer had, and the answer was "Many hundreds of megabytes". Needless to say, I was impressed, having known only 8-bit home computers.
Star Treknology (Score:2)
What's next? Warp drive [slashdot.org]?
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I don't think so, though I'm usually wrong. Engineers (try to) create things; scientists (try to) explain things.
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Open Source Medical Equipment (Score:1)
The product that I worked with wa
To stem the statistical comments: (Score:5, Interesting)
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?
Re:To stem the statistical comments: (Score:5, Insightful)
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.
Re:To stem the statistical comments: (Score:5, Interesting)
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!")
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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
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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
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"The infrascanner will never replace CT scans - but could be a highly useful new piece of medical technology."
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Re:To stem the statistical comments: (Score:5, Informative)
Please mod parent up (Score:2)
You don't understand, grasshopper (Score:2)
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
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Can you even read? (Score:2)
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
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Company Website... (Score:4, Informative)
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.
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Re:Company Website... (Score:4, Funny)
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Ever see the movie Constant Gardener?
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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
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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.
If you're not fam
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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.
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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.
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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
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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).
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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)
Doctor who? (Score:2)
Doctor Who spotted in India!
I wonder (Score:2, Funny)
Re:I wonder (Score:5, Funny)
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Damn straight!! I'm getting laid right no-o-oh, oh oooh yeah!
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I heard people with claustrophilia get kicks out of that.
A marvelous invention! (Score:4, Funny)
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The Slashdot blood test (Score:5, Funny)
How it works (Score:5, Informative)
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.
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A kitchen broiler is also non-ionizing radiation, but I suspect using it "continuously" on someone's brain is not such a good idea.
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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
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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.
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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'.
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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.
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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?).
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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
you're missing the point (Score:2)
I'm just saying that the argument "it's non-ionizing, therefore it's harmless" is stupid. Non-ionizing radiation can be very dangerous.
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Cheap?! (Score:3, Funny)
Who are you to call my blood clots cheap?!
False alarms? (Score:2, Insightful)
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This will be most useful (Score:1, Funny)
Could you scan a whole head? (Score:2)
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!)
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Heh, my captcha says "comply"
Alternatively ... (Score:1)
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
Good indicator of clots (Score:1, Funny)
Doctor Who? (Score:2)
Thanks, I'll be here all week.
Tri-corder like awesomeness (Score:2)
Any jamaican (Score:2)