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Cheap Blood Clot Detection Device
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.'"
I have a feeling that some surgeons will be sleeping alot better post-operation when they can monitor something like this more effectively.
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?
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http://www.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.
appleguru.org
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.
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.
I have nothing compelling to say
for your insensitive clots.
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
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.
I hate all sigs, mine included.
Oi!
Who are you to call my blood clots cheap?!
I don't entirely agree...
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.
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.
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 it should be used in conjuncture with existing tests was a brilliant masterstroke, which is only further reinforced by the fact that that is, actually, exactly what the article recommends.
And clearly, anyone in a third world village for which the measly 400,000 dollar CT scanner cost is too much should simply be airlifted to a larger national hospital where they can be treated properly. Airlifting a should be a fast and easy solution and is done in places like that all the time. And, of course, the astronomical and rising cost of healthcare in the US ensuring that 45 million of us have no health care shouldn't stop us from thinking about the children for whom the ridiculously expensive CT scanning procedure could save, assuming they ever went to a hospital. After all, access to good medical procedures shouldn't be gated on ability to pay, so it never is, right? And having a nurse do a couple of CT scans throughout a night "just to check" is a routine procedure in most trauma cases anyway, and as such the need for a cheap, easy, handheld, and fast scanner that has basically no operating costs besides a bathroom-break worth of time and a little drain on some rechargable NiCads is gratuitous.
This is exactly why I posted that some people would see a "98% accuracy rate" and immediately find fault. And you did, congratulations. Almost always, these are people who feel that you shouldn't use condoms because they're "only 99% effective when used correctly." Or those who decide not to take their diabetes medicines because it might only be about "95% successful" in stemming the tide of the disease. People want medicine to be black or white, good or bad, fixes you or not, but in reality medicine is a really mushy, nasty area. Certain tests may only have a 30% detection rate, but they do it anyway because detecting certain diseases at that level is better than not detecting them at all, especially to the people who get detected. Heck, CPR on cardiac arrest victims only reduces their death rate from 95% to 90%, which means that it's by and large almost useless. Almost. To those extra 5% who survive, it's very, very nice to have around.
Having a Sociology degree, I'm well aware of just how easy it is to make percentages lie, and am happy that people seem to have developed a healthy distrust for them. What you learn to trust, if data isn't readily available, is people. If people in the field are happy with this development, and the technological basis behind it seems sound, maybe it's worthy of further examination. If they're not, like the terrorist scanners, it's probably bunk.
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