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DARPA's Mind-Controlled Prosthetic Arm Could Be on the Market in Four Years

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Re: DARPA's Mind-Controlled Prosthetic Arm Could Be on the Market in Four Years

#11

Post by frisco »

sp332 wrote: post #10
frisco wrote: post #6

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 stimu…

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... Then you show that they continuously integrate it into their body representation This part is easy, isn't i…

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.

Re: DARPA's Mind-Controlled Prosthetic Arm Could Be on the Market in Four Years

#13

Post by 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.

Re: DARPA's Mind-Controlled Prosthetic Arm Could Be on the Market in Four Years

#14

Post by joeyo »

frisco wrote: post #11
sp332 wrote: post #10

Earlier quoted context omitted.

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... Then you show that they continuously integrate it into their body representation This part is easy, isn't i…

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. Cor…

  > 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

Re: DARPA's Mind-Controlled Prosthetic Arm Could Be on the Market in Four Years

#15

Post by [deleted] »

frisco wrote: post #6

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 stimu…

[deleted]

Re: DARPA's Mind-Controlled Prosthetic Arm Could Be on the Market in Four Years

#16

Post by stevenrace »

frisco wrote: post #6

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 stimu…

>> first, you do it in non-human primates and show that they can effective control the arm with the implant... Then you show that the implant is stable

Uncited, I'm not sure my reply is worth much - but such studies have already taken place.

Non-human primates have shown dexterity with such devices - but the 'interface' has a life of around 6 months due to prolonged , subtle vibrations in the 'brain probe' and scarring.

EEG inputs, while non-invasive, are susceptible to interference and work best with additional triggers such as speech to extend ones 'vocabulary' of movements. The reason being it's hard to to calibrate.

Lastly, electrocorticography (ECoG), seems a happy medium: picking up high frequency signals within the skull and atop the brain. So no issues with scarring and the signals are easier to map to brain regions.

'Google Tech Talk' on the subject (1hr)[1]: http://www.youtube.com/watch?v=mFWnTONOvVo

[1] Includes footage of monkeys + robotic arms @ 9m30s

Re: DARPA's Mind-Controlled Prosthetic Arm Could Be on the Market in Four Years

#17

Post by RyanHolliday »

ck2 wrote: post #13

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.

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.

Re: DARPA's Mind-Controlled Prosthetic Arm Could Be on the Market in Four Years

#18

Post by jokermatt999 »

RyanHolliday wrote: post #17
ck2 wrote: post #13

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.

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.

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.

Re: DARPA's Mind-Controlled Prosthetic Arm Could Be on the Market in Four Years

#19

Post by endtime »

ck2 wrote: post #13

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.

Why does it matter where this comes from? It's great technology that will improve people's lives.

Re: DARPA's Mind-Controlled Prosthetic Arm Could Be on the Market in Four Years

#20

Post by erikpukinskis »

frisco wrote: post #11
sp332 wrote: post #10

Earlier quoted context omitted.

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... Then you show that they continuously integrate it into their body representation This part is easy, isn't i…

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. Cor…

the brain will adapt to the prosthetic and the neural representations shift. You need to be able to deal with this

Why? Sounds like the brain is dealing with it pretty well on its own.

If the brain is good at one thing, it's taking note of, and adapting to, useful relationships in the structures it finds itself embedded in (affordances).

I think if you can get some kind of probe or grid of probes into an area that has even a vague chance of getting some activation during physical therapy sessions, then there's a pretty good chance the patient will be able to get from there to skilled motor control through practice.

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