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Prosthetic Hand Capable of Delivering Texture Sensations

Zothecula writes: A new prosthetic system allows amputees to feel familiar sensations and also, somewhat unexpectedly, reduces their phantom pain. Researchers at Case Western Reserve University and the Louis Stokes Cleveland Veterans Affairs Medical Center developed the system to reactivate areas of the brain that produce the sense of touch, but recipients of prosthetic hands reported their phantom pain subsiding almost completely after being hooked up to the system.

30 comments

  1. Not a medical professional, but: by kheldan · · Score: 4, Interesting

    Seems to me that when some area of your body doesn't get much or any stimulation for long periods of time, it gets more sensitive. If you lose a limb the associated sensory nerves get zero stimulation, as well as the associated area of the brain. Wouldn't those nerves and that part of your brain 'turn up the gain' and experience more 'noise' in the absence of 'signal' (hence 'phantom pain')? Then you attach something that provides a 'signal' again; 'gain' goes down, S/N ratio goes up?

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    1. Re:Not a medical professional, but: by timeOday · · Score: 1

      Yeah, it makes me wonder if phantom limb pains couldn't be alleviated with just a therapy session of random stimulation every once in a while. (Obviously this research in re-enabling some sense of touch/pressure is much greater than that.)

    2. Re:Not a medical professional, but: by gstoddart · · Score: 4, Funny

      Seems to me that when some area of your body doesn't get much or any stimulation for long periods of time, it gets more sensitive

      Must ... not ... make ... penis ... joke ...

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      Lost at C:>. Found at C.
    3. Re:Not a medical professional, but: by BringsApples · · Score: 2

      Yeah, that's exactly what they say happens. I don't know from experience, but I did see a really good documentary on a doctor that discovered that by simply tricking the brain, causing the phantom pain to go away. The patient that he was working with lost their hand and about 3/4 of the arm to the elbow. The patient reported that it felt as if his hand was squeezing harder and harder (as you point out, 'turning up the gain' and experience more 'noise'). So the doctor decided to try out setting up a mirror-box whereby the patient put his good arm and hand in, looked at the mirror, and would see what appeared to be his other hand (reflection) and by simply opening his other hand, the mind was tricked into seeing the missing hand as opening, causing the pain to stop completely immediately. The patient had to do this every now and then, to continue pain relief. But what an insightful doctor!

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    4. Re:Not a medical professional, but: by Frosty+Piss · · Score: 2

      Prosthetic Hand Capable of Delivering Texture Sensations

      ...to my penis.

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    5. Re:Not a medical professional, but: by tiberus · · Score: 1

      There is also a side-show like display where a persons hand is hidden behind a partition and a fake hand (placed where there hand 'should' be) is struck with a hammer causing the subject to flinch and act as their hand had been hurt. Brain Games mucked about with this one on of their shows. While this may just be triggering a fight of flight response, it interesting the note that the irrational portion of the brain seems to override the rational part (the one that 'knows' your hand is safe). After reading BringsApples post it struck me that these two cases may be opposite sides of the same coin.

    6. Re:Not a medical professional, but: by ArcadeMan · · Score: 1

      There's your problem right there: you're not supposed to have a coin in your brain.

    7. Re:Not a medical professional, but: by gstoddart · · Score: 2

      While this may just be triggering a fight of flight response, it interesting the note that the irrational portion of the brain seems to override the rational part (the one that 'knows' your hand is safe). After reading BringsApples post it struck me that these two cases may be opposite sides of the same coin.

      Well, here I'd substitute rational/irrational with 'conscious' and 'primitive'.

      You as a human know you are missing your hand (or in the case of your example that your hand isn't really going to get hit). However, the really primitive bits are still in there going "Hand, this is mission control, do you copy? Status report please." (Or in the case of your hand being there but not getting hit, "Alert! Hand, take evasive action" because its job is to do that kind of thing.)

      And this is probably well below what can be your conscious brain. So, no matter what your conscious brain knows and is aware of, the really primitive parts are handling other stuff.

      From the exceedingly little I recall from psych class (yes, only one, a long time ago) this is probably the structures of the brain that we share with alligators and pretty much everything else.

      I'm inclined to think kheldan probably nailed it (in very broad strokes), the brain is actively looking for a response from the limb and not getting anything. So maybe what this does is fool the primitive part of your brain into going "OK, status report from hand occurred, we can dial back the urgency". And I'm sure that part of your brain can't be overridden with "I know my hand won't get hit because this is just an illusion", so it responds as if it's happening.

      No matter what you know rationally, the really basic structures of your brain have their job, and still keep trying to do it.

      Though, this should be in no way be considered to be an accurate description of the physical stuff, just a high-level hand-waving thing.

      I used to know a quadriplegic who used to occasionally get an itchy foot ... despite the fact that he hadn't had any sensation below his shoulders for 25+ years. Scratching didn't alleviate anything, because it wasn't really itchy. At least, not in the way we tend to think of it. I'm sure the sensation was just as real.

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      Lost at C:>. Found at C.
    8. Re:Not a medical professional, but: by EnempE · · Score: 2

      Very interesting. Not quite the same as the article because the subject in this case is blindfolded and its a referred sensation.
      Nonetheless I didn't know about this and was happy for the reference.
      I think the /. appropriate content is at the links below

      Synaethesia in phantom limbs induced with mirrors (1996)
      V.S. Ramachandran & D Rogers-Ramachandran
      http://chip.ucsd.edu/pdf/Synst...

      Phantoms Limbs and Neural Plasticity
      V.S. Ramachandran & D Rogers-Ramachandran (2000)
      http://www.neurosciences.us/co...

    9. Re:Not a medical professional, but: by rogoshen1 · · Score: 1

      By documentary, did you mean House MD? :)

    10. Re:Not a medical professional, but: by K.+S.+Kyosuke · · Score: 1

      Why would anyone joke about not making penises?

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      Ezekiel 23:20
    11. Re:Not a medical professional, but: by BringsApples · · Score: 1

      No. I couldn't find it on youtube, and the one that I did find wasn't the same type of box as in the documentary that I originally remember seeing. The only difference between the one in the video that I posted and the one that I originally saw, was that the mirror was at a 45 degree angle, so that you wouldn't have to look at it from the side.

      I looked so much that now I think that maybe I'm remembering it wrong. All the same, it'd be better if it were at a 45 degree angle, so that you could simply look straight down at it. The documentary that I remember seeing had multiple brain issues, all with people with odd brain injuries and problems that they had to deal with after whatever accident or stroke they endured. One lady could only replicates in a half. I mean to say that she had a stroke and after that, if you showed her a picture of a flower, and asked her to draw it, she'd only draw half of it, and see it as complete. There was another guy that had been in a car accident and he was forever with the feeling that everyone that he was with, regardless who they were, he felt that they were an imposter - unless he was speaking to them on the phone. DAMN IT! Surely someone remembers this documentary, it's freggin killing me now.

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    12. Re:Not a medical professional, but: by Anonymous Coward · · Score: 0

      You can bet your last dollar that high-end fleshlights will be integrating this in short order. You heard it here first.

    13. Re:Not a medical professional, but: by Anonymous Coward · · Score: 0

      There is a STRONG correlation between phantom pains (and phantom limb sensation in general) and the ability to use any prosthetic... even something as basic as a rubber foot or hand. The brain extends its 'map' to include the prosthetic and lets people use it more naturally as part of their bodies. If the author of the piece was surprised by phantom pains decreasing, s/he probably isn't a doctor.

  2. As long as it can be disabled... by Anonymous Coward · · Score: 0

    ...stranger

  3. Phantom pain by dibdublin · · Score: 0

    I didn’t read the TFA, but if by “phantom pain”, they mean something akin to visceral hallucinations, then the phantom pain is independent of any locally-induced physical stimulation; the phantom pain is all in the head. It’s purely a hallucination. As always, follow the money.

    1. Re:Phantom pain by Ultra64 · · Score: 1

      "I didnâ(TM)t read the TFA,"

      Obviously.

    2. Re:Phantom pain by Anonymous Coward · · Score: 0

      Which simplifies, until you realize everything is all in the head.

    3. Re:Phantom pain by dibdublin · · Score: 0

      I didn’t read the TFA because the corrupt cops watching my unencrypted connection and hosing-up my Slashdot account are convinced that I can neither read nor write. Derp.

    4. Re:Phantom pain by Daetrin · · Score: 1

      Please don't take this wrong, but i took a quick look at your comment history and between that and what you've posted here you're sounding an awful lot like a friend i used to know. At first i thought she was just a little odd, but it turned out that she actually had some serious problems and some pretty bad stuff ended up happening because of it. If you really believe the things you're saying i think you should really consider talking to someone. I expect you'd be resistant to the idea of going to a psychiatrist, but perhaps you have friends or family you can discuss these concerns with?

      And if i'm just feeding a troll... oh well.

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    5. Re:Phantom pain by dibdublin · · Score: 0

      To put things in perspective, if you had an ex-wife, who happened to be a LEO, and she wanted to stick her nose in your business and cause you some “trouble” out of pure spite,...

      I’ll let you figure out the rest.

  4. Nerve mapping? by DoofusOfDeath · · Score: 4, Insightful

    Can anyone here explain to me the issue if/how we can map nerves correctly?

    For example: suppose someone's finger gets cut off, and then surgeons manage to reattach it.

    I assume that since there are many distinct sensory nerve endings on a finger, each of those must be carried along a distinct electrical pathway up to the brain.

    When a surgeon reattaches a finger, does he/she somehow get all of those hundreds(?) of connections to be lined up properly so that the mapping is the same as it was before the accident? If so, how? If not, what happens?

    1. Re:Nerve mapping? by gstoddart · · Score: 2

      I think that if you re-attach soon enough, the nerves end up re-mapping to the neurons as your brain sorts out what's what.

      Over time, your brain figures out that this particular one doesn't quite match what it used to, and then maps to the one which is there now.

      I suspect during the initial period until the nerves sort themselves out, you have really mismatched/clumsy sensation, but over time as the brain and neurons sort everything out it gets better.

      Of course, I'll freely admit I have no real understanding of the process, and that this is pulled out of nothing but speculation and things I think I remember hearing in terms of explanation.

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      Lost at C:>. Found at C.
    2. Re:Nerve mapping? by Anonymous Coward · · Score: 0

      We don't. A neurosurgeon just excises scar tissue (to promote regrowth), and visually aligns the nerve bundles using a microscope. The tissue is then sutured or glued in place. Nerves can regrow, but only very slowly. And they reconnect randomly, if they reconnect at all.

      The rest is up to the brain. It will correlate other stimuli (e.g. it sees one finger touching something) with the nerve sensations (e.g. a touch on the back of the hand), and will in time relearn to connect the two in the model it has for the body. It is very plastic in this way.

  5. A hop skip and a jump away by Anonymous Coward · · Score: 0

    Ok prosthetic hands are very important work. But i foresee the evolution of FUFME taking a giant leap forward

  6. Well duh by Daetrin · · Score: 4, Insightful

    "A new prosthetic system allows amputees to feel familiar sensations and also, somewhat unexpectedly, reduces their phantom pain."

    This seems like one of those things that people might very reasonably not think of ahead of time but which seems blindingly obvious in retrospect. It would probably be expected that if you managed to reattach a severed limb that there wouldn't be any phantom pain afterward. ("Real" pain during the healing process yes, and perhaps lingering aches as one might have with any injury, but not phantom pain.) You'd also expect the same to hold true if you managed to grow a new arm and attach it properly.

    But a simple prosthetic isn't enough to prevent or cure phantom pain. So one would expect that at _some_ point in the process between no nerve connections with a peg leg (or equivalent) and full connection with a regrown/reattached limb that the phantom pain would disappear. I guess they just encountered that point earlier than they might have expected.

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  7. In hindsight by blueshift_1 · · Score: 2

    This is one of those obvious things that makes more sense afterward. Clearly the nerves have had years of constant input and you just take that away... it make sense that system would create false/phantom input as an assumption that it should be receiving some sort of signal. By increasing the amount of input, it creates a more normal state for the body... the more you knooooow.

  8. What if Oracle happens to have patents on the API by Mister+Liberty · · Score: 1

    You can't even give Larry Ellison the middle finger.

  9. Sign me up... by Anonymous Coward · · Score: 0

    But does it have Oculus Rift Support?

  10. nice by ilusion17 · · Score: 1

    great man....nonton bokep gratis