
DARPA's Mind-Controlled Prosthetic Arm Could Be on the Market in Four Years - raphar
http://www.fastcompany.com/1725799/darpas-mind-controlled-prosthetic-arm-could-be-on-the-market-in-four-years
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frisco
So I totally want this to actually happen. However, they gloss over all of the
actually hard parts. Cool, DEKA's built a sweet anthropomorphic robotic arm. I
have no doubt that part works. But you don't just jump to running a human
study from that: first, you do it in non-human primates and show that they can
effective control the arm with the implant. Then you show that they can
interpret feedback from the arm stimulated into their brain. Then you show
that the implant is stable and immunologically accepted over a long period of
time (warning: deep, hard unsolved problem). Then you show that they
continuously integrate it into their body representation (not necessarily
hinted by the prior control study). Then you cautiously do a human surgery and
see if they can control it, and the brain doesn't reject the implant after a
year. Then five patients. Then apply for FDA approval, expedited or otherwise.

AFAIK there's never been an implant study done using the Luke arm. Therefore
we've never tried to build control models from cortical activity for it.
That's a hard problem in and of itself. Jumping straight to a 5-person human
study is _insane_. Furthermore, the idea that human patients are going to get
intracortical feedback from the arm is crazytalk. It's just not happening.
Electrical stimulation cooks the brain and causes seizures, and optical
stimulation requires gene therapy (!) and has all kinds of long-term problems
right now.

TL;DR: awesome I hope it works. They'll bring a needed device to market and
solve about 10-15 of the hard problems of brain-machine interfacing for us at
the same time!

~~~
sp332
_Electrical stimulation cooks the brain and causes seizures_

From Wikipedia: deep brain stimulation has been FDA-approved for tremor since
1997. More treatments have been approved since, like Parkinson's, dystonia,
major depression, and chronic pain.
[https://secure.wikimedia.org/wikipedia/en/wiki/Deep_brain_st...](https://secure.wikimedia.org/wikipedia/en/wiki/Deep_brain_stimulation#Potential_complications_and_side_effects)

 _Then you show that they continuously integrate it into their body
representation_

This part is easy, isn't it? People integrate tools into their body image
innately and easily. I don't think _that_ will be very difficult.

~~~
frisco
Deep-brain stimulation is different than cortical microstimulation. DBS is
injected into the basal ganglia and excites an area of the brain that's
effectively atrophied. This can be done relatively safely for things like
Parkinsons, even though it's definitely not your first choice of treatment.
It's still somewhat cooking the brain, however; in the cases where DBS is used
that just doesn't outweigh the benefits. Cortical stimulation into primary
sensory cortex is a totally different animal, and tends to cause seizures much
more frequently. The brain is kind of wired to seize, when you look at it, and
it's amazing it doesn't more often. Also, you can't map receptive fields --
which specific areas of cortex correspond to what sensation in what part of
the body -- if your patient is an amputee, and there's no "master map" that's
precise enough since it varies between individuals widely. Further, DBS is
just designed to grossly "drive" an area of the brain; in ICMS you'd want to
precisely excite a few cells to create a sensation. ICMS in practice just
floods its surroundings with current in a rather blunt way. Optogenetics are a
solution but have their own problems (i.e., requires genetic transfection)
that make them unacceptable for use in humans today.

 _This part is easy, isn't it? People integrate tools into their body image
innately and easily._

Yes -- but as a patient lives with a prosthetic full time, as opposed for a
few hours at a time like in most monkey studies, the brain will adapt to the
prosthetic and the neural representations shift. You need to be able to deal
with this and understand what that learning looks like, which we can sort of
do right now, but no one's really done a long-term-continuously-living-with-a-
prosthetic study. You generally don't try to solve complete unknowns like that
for the first time in humans. Humans would be a poor platform, anyway, since
you can't observe and record from them 24/7 in a controlled environment.

~~~
joeyo

      > Also, you can't map receptive fields -- which specific
      > areas of cortex correspond to what sensation in what part
      > of the body -- if your patient is an amputee, and there's
      > no "master map" that's precise enough since it varies
      > between individuals widely.
    

This is a very good point but I don't think it's an insurmountable problem.
After amputation or deafferentation the "unused" parts of the cortical map get
taken over by adjacent representation areas. However, after hand
transplantation cortex recovers some of it's normal organization[1]. So it's
at least possible that cortical stimulation could lead to the same result.

1\. Frey et al. Chronically deafferented sensory cortex recovers a grossly
typical organization after allogenic hand transplantation. Curr. Biol. (2008)
vol. 18 (19) pp. 1530-4

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Niten
> Finally, laypeople will benefit from the Defense Advanced Research Projects
> Agency's (DARPA) mad scientist projects

Yeah, because that whole Internet thing and GPS didn't really count for
much...

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zoomzoom
If this turns out to be a real FDA approved implant, the potential to improve
the lives of paralyzed people is staggering.

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blhack
This looks like the DEKA arm. Here is Dean Kamen talking about it:

<http://www.youtube.com/watch?v=AoY1cItRiHA>

Even if it isn't the same thing, this is a pretty interesting video.

~~~
sp332
I worked at DEKA for a while. Although I didn't work on the Luke arm, I got to
see a few demos. It's my understanding that the _control_ system is very
loosely coupled to the _user_ inputs. I think it's an expansion of the control
mechanism for the iBot, which took input from hundreds of sensors but could be
controlled with just a joystick and a single button. The Luke arm currently is
controlled by pressure sensors in the shoes and on the chest, so you wiggle
your toes and flex your muscles to command the arm. It also has very
impressive force feedback. But other input mechanisms and feedback systems
could be implemented, including direct mental manipulation.

Edit: here's a good demo video <http://www.youtube.com/watch?v=R4X_l2XOz8g>

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StavrosK
At first, I thought that it would be very cool to have such an arm, for a
second entertaining the thought of someone chopping their arm off just so they
could be a cyborg. However, a moment later, I thought "three arms", and
immediately I saw the improvement.

I bet some rich guy will soon turn into some robo-Shiva.

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RyanMcGreal
Cue the Dr. Strangelove jokes.

~~~
evo_9
More like the Six Million Dollar Man theme...

~~~
RyanMcGreal
Watch the arm: <http://www.youtube.com/watch?v=59YKlP--PhU>

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arrel
Did Arnold Schwarzenegger's face flash through anyone else's mind while
reading this?

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ck2
Sigh, why does this have to come out of the military industrial machine?

Little known fact: over 1,000 soldiers in Iraq and Afghanistan have lost a
limb (out of 41,000 wounded that survived because of more advanced medicine).

I hope they don't use this development to justify that it's okay because we
certainly don't talk about it much otherwise.

~~~
RyanHolliday
Isn't it possible that this is why it comes out of the military industrial
machine? Surely a lot of advances in trauma treatment, bandages, surgery, and
all kinds of other medical advances have come from the military industrial
machine as well.

I don't see the need to politicize this, and I don't think the numbers
associated with the wars would be little known to people here.

~~~
jokermatt999
Indeed. If you watch Dean Kamen's TED Talk, he says that's part of why he
created it. It's not to justify sending soldiers to lose their limbs, it's to
help those that already have. He showed a lot of respect and ...sadness, I
guess for the soldiers who had lost their limbs, and genuinely seemed to want
to help.

