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A Better Way To Make Mind-Controlled Prosthetic Limbs

Posted by Soulskill on from the resistance-is-futile dept.

the_newsbeagle writes: To make a brain-machine interface, you need a way to capture neurons' electric signals. The most precise and most invasive way uses implants that are stuck in the gray matter. The least precise and least invasive way uses EEG sensors stuck to the scalp. But researchers at Johns Hopkins University say there's a third way that gets the best of both worlds, which is not too invasive and fairly precise. They use ECoG systems, in which a mesh of electrodes is placed under the skull, draped over the surface of the cortex.

They're testing their systems on epilepsy patients, who have these ECoG systems inserted anyway while they're waiting for surgery (the electrodes record the source of their seizures). The researchers are capturing these patients' movement commands from their brains, and using them to control robotic limbs. Someday such a system could be used by amputees to control their prosthetic limbs.

28 comments

  1. Not too invasive? by opusman · · Score: 1

    Having anything placed under my skull in direct contact with my brain sounds a little invasive to me.

    1. Re:Not too invasive? by i+kan+reed · · Score: 4, Insightful

      I'm going to guess, though I could just be acting like an insensitive clod, that you've never had to deal with the debilitation of a missing limb. I feel like it's going to be a pretty appealing option to a lot of people.

      And as far as "invasive surgery" goes, amputations are pretty much top of that category too.

    2. Re:Not too invasive? by JoeDuncan · · Score: 4, Informative

      The difference being that the ECoG system appears to simply lay the electrode mesh on top of your cortex, traditional direct neural links involve actually puncturing and penetrating neural tissue with many tiny pins.

    3. Re:Not too invasive? by Anonymous Coward · · Score: 0

      I'm with this guy, I have an injury where my leg is hard to move and only randomly goes out and I have already asked for surgery (been told no and that it is permanent and degenerative though) so I can imagine what it is like to have that limb gone forever.

      Much like a starving man with a gun, after a while, that surgical procedure starts looking mighty friendly.

    4. Re:Not too invasive? by Anonymous Coward · · Score: 2, Informative

      Not that tiny, I did neuroelectrical design for over a decade. Electrodes outside the local motor nerves themselves, have a *ridicious* amount of noise from irrelevant neural material. Even electrodes *on* or in the nerve have ridiculous amounts of noise. And worse, as soon as some fumbfutz tries to digitize and sample it, they throw out most of the data. The signals are not like binary signals, on or off. They're pulse driven. state changes in the right amount, on the right nerves, trigger motion or sensation. The electrical equivalent my monitoring the brain is like monitoring an intersection by listening to the traffic. You've already spent a lot of time gathering information, and by the time you have enough data to be certain of the signal, it's too late and too gross a measurement for detailed mechanical manipulation.

      Oh, and the smaller the electrode to help isolate the signals, the more electrical noise you pick up from being stuck in a saline medium, trying to read electrochemical signals in a conductive medium. It's an unavoidable problem until and unless Dr. Rosen's ar some other work succeeds in create an electrode array that transects the nerve and has the nerve cells actually feeding *through* the array.

      I'm afraid similar work was done with myo-electric signals to control the original "Boston Arm", which used skin electrodes on the shoulder of the missing arm. The phase delay necessary to sample and collect a valid signal is too large: that's one of the reasons the Boston Arm never became popular.

      Mind you, it was cool as futz. I talked to the engineer who did the mechanical design, who actually worked for an insurance company. When I asked him how much it could lift, he said "12 ounces". When I asked him why, he brought his beer bottle to his mouth....

  2. Just wait until they become hackable by denis-The-menace · · Score: 1

    Imagine:
    your limb(s) hitting you.
    your hand(s) crushing everything.
    Your brain getting zapped by the interface.

    "good times" are coming.

    --
    Obama's legacy: (N)othing (S)ecure (A)nywhere and (T)error (S)imulation (A)dministration
    1. Re:Just wait until they become hackable by i+kan+reed · · Score: 1

      Reminder: you're talking about trolling the physically disabled.

      Socially, that's usually considered off limits.

    2. Re:Just wait until they become hackable by Anonymous Coward · · Score: 0

      Is he or is it a legitimate concern? perhaps not brought up in the most tactful way.

      Seems something very worthy of consideration, how frustrating is it when the menial things in your life get disrupted by hackers, be it video games, bricked phone, random credit card charges.

      then put that in perspective with losing control of your faculties to provide some kid miles away a lol.

    3. Re:Just wait until they become hackable by preaction · · Score: 1

      Have you been to the internet? Do you think anything is off limits?

    4. Re:Just wait until they become hackable by i+kan+reed · · Score: 1

      Genuinely and honestly, yes.

    5. Re:Just wait until they become hackable by Anonymous Coward · · Score: 0

      Welcome to the Internet (NSFW).

    6. Re:Just wait until they become hackable by Anonymous Coward · · Score: 0

      do you think *EVERYONE* else thinks that also?

    7. Re:Just wait until they become hackable by denis-The-menace · · Score: 1

      It is a legitimate concern not brought up in the most tactful way. Anybody in their 20s should push for this because they will have one in 30 years or so. It might even be a job requirement ( https://www.youtube.com/watch?... ) (yup, it still gets hacked in the series)

      Just look at what they can do with a CAN-bus in cars today:
      https://www.google.ca/search?q...

      Now imagine people instead of car. Yup, that's coming. Nothing's off limits.

      If it's doable, some asshole will go for it.
      Whether it's for kicks or cash.

      --
      Obama's legacy: (N)othing (S)ecure (A)nywhere and (T)error (S)imulation (A)dministration
    8. Re:Just wait until they become hackable by Anonymous Coward · · Score: 0

      Reminder: you're talking about trolling the physically disabled.

      Socially, that's usually considered off limits.

      That SWATting, though.

  3. electrodes take up space in the brain regions by wherrera · · Score: 2

    The only way this could work is if the electrodes can be made much,much thinner than paper thin, and even then they might irritate nearby tissue. It's a huge technical challenge. Better to use a smaller electrode surface area and train the patient to signal to the electrodes.

    1. Re:electrodes take up space in the brain regions by Rhywden · · Score: 1

      Are 76 micrometers thin enough? http://www.nature.com/nmat/jou...

  4. Use Radio FFS by Anonymous Coward · · Score: 0, Interesting

    Do these guys understand their physics? If they can detect activity in the near field, then it will modify a return signal in the far field. A wideband radar will return all the neural activity, its just a matter of datamining the backscatter.

    If they have issues with attenuation, then they wrap the signal in a range of lower frequencies and use them to penetrate.

    Completely non-invasive.

    If they increase the amplitude, they can then drive neurons too in highly complex ways.

  5. I/O by Iamthecheese · · Score: 2

    I believe brain implants are the human-computer interface of tomorrow. They can offer I/O at speeds and bandwidths limited only by our very elastic brain tissues and the only downsides are the "ick" factor and the fact that we're still learning how to do it safely. For not only virtual limbs but control of any electronic device, typing, cursor movement, and other sensing I say bring it on!

    --
    If video games influenced behavior the Pac Man generation would be eating pills and running away from their problems.
  6. Neurons aren't just in the brain by king+neckbeard · · Score: 3, Interesting

    There are also neurons in the rest of the body. Assuming these are replacement limbs instead of supplementary limbs, why wouldn't they intercae with the neurons the body was previously using to do those communications, e.g., control a replacement hand by connecting it to the neurons in the wrist?

    --
    This is my signature. There are many like it, but this one is mine.
    1. Re:Neurons aren't just in the brain by sumdumass · · Score: 1

      I was wondering the same thing. A possible answer might be that if the limb isn't there long enough, the ability to send the neurons along the proper paths may be lost so capturing them closer to home might be a better solution. Or it could be because the implants are already installed for other purposes in the patients they are studying and getting the control process to work is more important at this stage than how it is eventually used. It could be that they plan on moving the control devices later and taking advantage of the others.

      Something else I was thinking about, how long before something like this can control the entire body making it possible for dead people to be artificially resurrected and have a computer installed in the brain. sort of electric zombies or something. Perhaps this will end up with robots being mind controlled also- where an operator thinks about grasping an object in a hazardous area and the robot does so as naturally as a human could via a prosthetic. This might make dangerous situations like entering a burning building or a fukishima type plant disaster easier due to a lot of the controls being created for human interaction verses remote robotics.

    2. Re:Neurons aren't just in the brain by Mal-2 · · Score: 1

      Perhaps this will end up with robots being mind controlled also- where an operator thinks about grasping an object in a hazardous area and the robot does so as naturally as a human could via a prosthetic. This might make dangerous situations like entering a burning building or a fukishima type plant disaster easier due to a lot of the controls being created for human interaction verses remote robotics.

      You just reinvented the waldo.

      --
      How is the Riemann zeta function like Trump rallies? Both have an endless number of trivial zeros.
    3. Re: Neurons aren't just in the brain by bugnuts · · Score: 1

      Maybe so it can work on those paralyzed from a spinal injury?

      I wondered the same thing.

  7. The Borg by Anonymous Coward · · Score: 0

    Clearly what is needed here are Borg nanoprobes to construct the necessary man-machine interface
    http://en.memory-alpha.org/wiki/Nanoprobe

  8. Paralysis by Anonymous Coward · · Score: 0

    Once they've captured the brain signals, why not work on piping those same signals through the body to override spinal cord damage.

  9. Under the skull? by Anonymous Coward · · Score: 0

    According to the summary:

    "They use ECoG systems, in which a mesh of electrodes is placed under the skull, draped over the surface of the cortex."

    But under the skull is not over the surface of the cortex. Under the skull is over the surface of the dura matter.

    http://weillcornellbrainandspine.org/sites/default/files/meninges-adult-lg.jpg

    There are several more layers before you get to the cortex.

  10. Saw it on Extant by Anonymous Coward · · Score: 0

    That's odd, I saw the described device on CBS's show, Extant.

  11. Well that is nice an all by Anonymous Coward · · Score: 0

    But how about Doc Oc suits so the rest of us can stand up to Spiderman?

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