A Bionic Leg That Rewires Stroke Victims' Brains

waderoush writes "A startup called Tibion in Sunnyvale, CA, has begun selling battery-powered robotic exoskeletons that help stroke victims with one-sided weakness relearn how to stand, sit, walk, and negotiate stairs. The leg isn't a permanent attachment; the company says patients who use the device for 45 minutes a week for four weeks experience significant gains in walking speed that persist and even improve months after the treatment. They believe that the $40,000 device — which includes sensors that respond to subtle signs of user intentions, such a shift in weight — provides feedback that triggers neuroplasticity, the brain's ability to rewire itself to repair damage."

Comments

Difference

[MyLongNickName]

Here is the difference between a journalist writing something and what a scientist says.

Journalist: "Bionic Leg That Rewires Stroke Victims' Brains"

FTA: "And this movement provides proprioceptive feedback that, over time, helps patients’ brains rewire themselves, so that they are eventually able to carry out the motion on their own"

Draw your own conclusions

Re:Difference

[MyLongNickName]

To be fair, I should put the article's title here, not the summary's:

"Can Tibion’s Bionic Leg Rewire Stroke Victims’ Brains?"

Re:Difference

[JackOfAllGeeks]

Is there really a significant difference between "bionic leg rewires brain" and "bionic leg provides feedback that allowes the brain to rewire itself"? Aside from brevity.

Re:Difference

[tedgyz]

I think we are arguing semantics. I easily interpreted "rewires brain" to mean what it says - "allows the brain to rewire itself". I did not picture some Brazil style surgery.

Re:Difference

[Wansu]

  FTA: "And this movement provides proprioceptive feedback that, over time, helps patients' brains rewire themselves, so that they are eventually able to carry out the motion on their own"

proprioceptive, ain't that an erection that last more than 4 hours ... no wait, that's priapism ...

Re:Difference

[JackOfAllGeeks]

Your argument isn't that this doesn't "rewire" the brain, but that everything does. Which would be a valid point to make (even if it doesn't really refute the claim) except for that fact that this apparently has added benefit to stroke victims that instruments, sporting equipment, and even traditional therapy doesn't. To be fair, it's still an unproven benefit in that there doesn't seem to be and hard research to back it up, but I don't think it's enough to warrant pulling the thread of "everything rewires the brain." That smells of just being pedantic.

Re:Difference

[Thing 1]

Currently reading "The Brain that Changes Itself", about neuroplasticity. It's really neat that they are able to provide new types of inputs, and our brains rewire themselves to obtain information about the world through those new inputs. There's a bracelet (or anklet) which vibrates the part pointing to magnetic north, and wearing this, people start to have a much larger sense of direction. Also, those psychology experiments that showed rewiring -- wearing glasses that shifted the view 30 degrees to the left, and playing catch with a ball. Initially they threw the ball too far to the left; with practice, they were able to throw it to the other person. Then they took the glasses off, and they threw to the right for a while! Anyway, really cool subject, I highly recommend the book. Personally, I was born with one eye and have been saying for years that "The neurons that would have gone to serve the input from that eye, got re-purposed to make me more intelligent", and it seems I wasn't far off the mark (so far what I've read is that severed nerves have a "brain map" that gets taken over by adjacent nerves, so it's not directly intelligence per se, but I'm a family statistical anomaly as well :) ).

Re:Difference

[tehcyder]

My conclusion is that the journalist's shorter version conveys the same basic information as the scientist's, but is much more likely to make me read the article.

It's not like the former is saying "immortality elixir invented" when in truth it's just a way of ameliorating cold symptoms.

Re:Difference

[sjames]

Or for that matter, in much the same way more conventional rehabilitation does. This is an evolutionary rather than revolutionary improvement, but it certainly looks like an improvement.

Are there any studies?

[KublaiKhan]

Not to throw cold water on what sounds like a fascinating innovation, but are there any studies that show that it works?

Or is it just a very expensive placebo that provides a magic-feather effect for the stroke patients, giving them enough support and confidence to put some more effort into their therapy?

Though if it had a bit more oomph to it, I could see quite a lot of use for people with extensive lower-body damage...internalize the structure, and it sounds like it could be a pretty handy prosthetic, albeit an expensive one.

Re:Are there any studies?

[MyLongNickName]

FTA: "... At least, that’s the theory. “I can’t tell you for a fact, but the hypothesis is that we are amplifying residual intention,” says Remsberg. “This allows for an intensive level of training, which appears to capitalize on neuroplasticity, the ability of the brain to rewire around regions destroyed by stroke.” (Remsberg expands on this idea in the video on page 3.)

If larger studies prove that the device is as effective as the early results seem to suggest, Tibion exoskeletons could become standard equipment at the 15,000 skilled nursing facilities and 2,000 rehabilitation hospitals in the United States"

So, I would say that this is still being investigated.

Re:Are there any studies?

[trb]

I agree, show me the research. I work in the field of rehabilitation robotics for stroke, and I am not aware of science that says that simply assisting someone's movement will improve their neural/muscular function.

I've been working on this problem for 10 years (as a software designer, not a neuroscience researcher) and researchers who use our robots have many studies that show patient improvement, but this comes from providing controlled rehabilitation exercises, not just by driving their limbs with an exoskeleton. I think research indicates that the rehab benefit comes from having the patients work to control their own limbs (with assistance and guidance if necessary from a robot or therapist) rather than by just driving the limbs without the patient working the neural paths.

refs:
N Engl J Med 2010; 362:1772-1783 May 13, 2010
http://www.nejm.org/doi/full/10.1056/NEJMoa0911341
http://www.interactive-motion.com/clinical_research.htm

Re:Are there any studies?

[kanto]

It's kind of logical when you think about it, the best example I know of was in a documentary where a woman with her inner ear poisoned regained her sense of balance when she trained with a cap that showed her her stance and so enabled here to remain in balance; a bit like when in signal processing where you use the original signal as target when training a filtering system to remove noise etc. You just need to have some capability left and the brain will be able to correctly notice those parts.

This is probably the same documentray; neuroplasticity abc lateline

Re:Are there any studies?

[MozeeToby]

The, at this point anecdotal, evidence is based on people who are beyond the generally accepted 12 month window of improvement. They showed an increase in walking speed of .2 m/s while using the device, and an additional .1-.2 m/s improvement in the months following the device's use.

So, if their results hold up in larger studies, I would say that this is either a new effect, or the conventional wisdom is dead wrong and we're giving up on rehabilitation too soon. Either way it's fantastic news for stroke victims. Some of the people they talked about were able to double their comfortable walking speed, that's a pretty big deal for a stroke victim who was told by their doctor "this is the best you will ever be able to walk".

Re:Are there any studies?

[spads]

What seems to be the contention here, is the possibly unique advantage of, specifically, proprioceptive feedback, as opposed to the more conventional theory of standard exercise, in re-wiring these atrophied areas of the brain. Proprioceptive feedback is specifically the feedback sent to the brain from a limb due to its re-positioning (in space). The atrophy of the brain area might obviate the possibility of normal exercise. Thus, the question comes, might any benefit be purely gained from an externally driven re-positioning (ie. to drive a proprioceptive process)? Also, the timed disengagement of such a facilitated re-positioning could couple pure proprioception and active exercise, if it reaches a range for which the neural machinery is still active. Of course, this part is highly conjectory, as remains the theory of pure proprioceptive rehabilitization itself.

This theory just reminds me of something which I feel has been rehabilitory for my own atrophy following a couple of knee procedures over 30 years ago - the elliptical runner. This, too, does a facilitated (passive) action (ie. the normal rotation of the machine pedals, driven by both legs), coupled with active action, as one pushes against the pedals. Notably, a concsious effort seems (unsurprisingly) beneficial here, as the atrophy of the limb can be well conceived as a sort of "hollowness" which you are attempting to restore.

In any case, there seemed to be some interesting parallels here. For myself, I don't see any particular advantages over the elliptical runner, though there could be for those for whom that would prove too vigorous.

Re:Are there any studies?

[Anonymous Coward]

Somebody is jealous that others thought of it before him.

Re:Are there any studies?

[sjames]

Your deficit was primarily muscular and/or skeletal though, wasn't it? This is for neurological deficits.

It strikes me as being like a very precise version of the way sports are often taught where the student is taken through the needed motion by an instructor to help them learn it.

Walk the Man

[Metabolife]

"Why does the man walk his leg?
      Because the man is smarter than the leg. If the leg were smarter
      than the man, the leg would walk the man."

Re:Walk the Man

[MattMattMatt]

I'm pretty sure my third leg walks me wherever it wants.

Interesting

[Coldegg]

It's good to see the advancements that they are making in this area. Along with the system developed in Israel recently for parapalegics, advancement in the mobility realm seems to be improving lately.

Hopefully they will put together some decent studies so that it not only gets additional public attention, but health insurers might begin to pay for usage in treatment (if research is conclusive of course).

Great stuff!

Doc Octavius?

[dkleinsc]

We've never had bionic limbs cause changes in people's minds before, right?

Such an interesting premise

[Agent__Smith]

While the preliminary results are somewhat limited, what a facinating idea. It continues to astound me how versatile our brains really are. The original internet, capable of rerouting around problems.

I want one that makes me run faster and jump higher. Like those suits in Avatar.

Executive summary

[93 Escort Wagon]

This prothesis is the functional equivalent of having Dan Dailey standing there, playing the ukulele and singing "I'm gonna move that toe" over and over?

So there is a market for this stuff ?

[frog_strat]

Stroke has affected my immediately family so it is nice to see something that can help people to walk, and possibly enhance their brain function. But who could afford this ? The pool of people that have insurance, insurance that actually pays instead of fighting, is getting smaller all the time.

Re:So there is a market for this stuff ?

[trb]

Problems of an aging and stroke-prone population cross international boundaries. "Who can afford this?" and "Will insurance pay for this?" are good questions, and the answers are different from country to country, and from year to year. Note also that hospitals and insurance companies are slow-moving organizations. If robotic science was a clearly safe magic pill that cured strokes, I assume we would find someone to pay for that cure. But with cures that provide only some degree of improvement, the treatments go through the normal course of medical research, and if the treatments are found to have sufficient and lasting efficacy, the medical and insurance fields eventually adjust to incorporate the new treatments.

As it is, I've seen research that shows repeatable quality-of-life improvements from our robotic therapy, and I've been at clinics and hospitals where patients and their families have given me heartfelt thanks for my work, which, while very gratifying, does not count as a controlled repeatable verifiable research result.

Re:If you're going to put it like that

[trb]

then you are saying that exercising stroke vitcim's affected limbs doesn't improve their mobility. Which is kind of a dumb thing to say.

Yes, that's almost what I'm saying - that it doesn't necessarily improve mobility. I work on stroke therapy robots that can move people's limbs around in whatever way we feel makes a difference. Through long research, we have found that some ways make a difference, and other ways do not make a difference.

Our researchers have been working on the problem for 25 years - that is, we have research published back to the mid-1980s, for example:

http://www.jneurosci.org/cgi/content/abstract/5/7/1688

This is a seminal paper by one of our researchers, that spawned the field of rehab robotics. I have already posted other links to research earlier in this thread.

Note well, I'm not a researcher, I write software to control rehab robots. But I know that in our researchers' papers, they do experiments where one group of patients gets beneficial rehabilitative exercises on our robots, and a control group gets non-beneficial "fake" exercises on our robots, where the patient's limbs are moved by the robots, but not in a beneficial way.

So be careful when you use phrases like "It's so obviously likely to be useful."

You imply that I might have a problem with successful results from a competing method, but it's not so. I'm saying there's a difference between "shows promise" and research results, especially from research that has been going on for 25 years, and going on in earnest (it took a while to create and refine the robots) for more than 10 years.

Isn't there a much bigger potential?

[odirex]

If I'm understanding how this works correctly, I think a more advanced version of this technology be able to, for example, train a person to pitch a perfect curve ball or do a martial arts move.