Bionic Leg for the Commercial Market

Jay writes "I thought you may be interested in this crazy-cool fully powered bionic knee called the Power Knee. It's made by Victhom, a French-Canadian company and will be marketed by Ossur, an Icelandic prosthetics company and one of the biggest prosthetics companies in the world. You may have seen them in the news lately with their Rheo Knee or rheomagnetic computer controlled knee. This new Power Knee takes it to the next level with full active power. Supposedly it will allow people to walk up stairs and the like. Here's the link to Ossur's Power Knee website with photos and video, and to Victhom's website. Cool video, amazing device."

Comments

i don't really get it

[killa62]

so is it just a replacement leg for someone who lost their leg? So it read your body's "mind" and does whatever you want?
So if you jump on landing it will bend a little so that it coushins the jump?
and if you run it mimics how your other leg moves so that your body can't tell if it is a real or fake leg?

Re:i don't really get it

[multiplexo]

Above knee (trans femoral) amputees have a harder time of walking with most prosthetic knee joints because they have to learn to modulate the swing of their leg using the muscles in their thigh, glutes and lower back. Eventually many of them learn to do this well enough so that you can't tell that they are wearing a prostheses. However this is very fatiguing. The Ossur C-leg was a major advance for AK amputees because the microprocessors could modulate the swing of the lower portion of the leg, making it swing farther for a faster gait and not so far for a slower gait.

However for climbing up and down stairs AK amputees have a harder time, even with a smart knee such as that in the C-leg because they don't have the muscles to modulate their gait and the muscles through the knee that help you go up and down slopes and stairs. Going up and down stairs with a BK amputation (trans-tibial) is also difficult due to the loss of the muscles and joints in the foot but is manageable, for an AK amputee all of the work in going up and down stairs has to be done by the remaining leg, which gets tiring very quickly.

I've met a lot of AK amputees (I'm a BK amputee) and this leg will be a huge advance for them, now we just need to get their insurance companies to pay for them, which isn't easy because a sophisticated AK prostheses can end up costing 50 or 60k when all is said and done.

Another application?

[Pi_0's don't shower]

While this looks promising for prosthetics, as the article says, I wonder if this has any implication for simple knee-replacement surgery? As someone whose family has a history of knee replacement surgeries, it sure would be nice if they could make an artificial knee that would last more than 15 years...

Re:Another application?

[YU Nicks NE Way]

Is it inconvenient? Well, that depends. If you don't mind having your leg broken in two places with a chisel, then having someone take a 3/4 in bit to the butt ends of the long bones, then glue in a foreign object...and then sew up the incisions they made to cut your leg off to all that work...why, no, it isn't inconvenient.

Otherwise, I gather it's held to be moderately unpleasant.

power consumption

[phloydphreak]

The article states the the prosthetic generates its own power, probably a kinetic power generator. How much power can such a device output, especially to run an embeded AI which determines the movement of the limb. Does the limb eventually run out of power (reducing it back to a normal prosthetic)? Such as, if the limb is not used for an extended period of time? The very design of it is ingenious though, and I would not doubt that they have made the system fully self-sufficient. Very cool.

Re:power consumption

[ForestGrump]

Well, "normal prostetics" are quite impressive at times.

My Dad used to have a co-worker who lost his leg to cancer in his 20's. He walked fairly well, minus the slight awkardness (more like a limp). If you saw him around the office, you'd assume he had a bad day of tennis, not a missing leg.

I imagine the leg would act like a "normal" prostetic, and only give power in short burstsm to help you up a slope or a flight of stairs. The rest of the time, it would recharge the battery (hopefully that doesn't weigh too much).

Re:power consumption

[Scrameustache]

The article states the the prosthetic generates its own power, probably a kinetic power generator.

I saw a tv "documentary" on this: The calf of the leg is a battery (or was in one of their prototypes), and the person wearing it, btw, wears a special sole in his other shoe that gives the bionic leg information on when he's stepping and lifting his foot and so on.

A useful feature that is missing

[David_Shultz]

A feature that would be very useful, though I didn't see it mentioned anywhere on the site, would be the ability to "punish" the knee for making an error. Most learning algorithms work by having a teacher tell them what sort of actions/decisions were right or wrong. With this system, there is probably some sort of hardcoded teacher, which is not necessarily the best way to do things -the best judge of what you want your bionic leg to do is probably yourself, and not a programmer somewhere. For example, if your leg starts to give way as youre walking up stairs, forcing you to catch onto the rail to prevent serious injury, you should have the ability to say, basically "bad leg!". By pressing the appropriate button, you would teach the AI that it made a mistake, and it would modify itself as necessary. A similar system might be useful for telling the system when its doing a good job, perhaps a dial that simply represents the users satisfaction.

Naming?

[Grayden]

Is it by coincidence or by design that the name of the company that makes the replacement limbs is more or less a homonym for "victim"?

When I see "Victhom" I see it being pronounced "VIC-tum".

Steve Austin, Astronaut - A man barely alive . . .

[craXORjack]

Gentlemen, we can rebuild him... We have the technology. We have the capability to make the world's first bionic man. Steve Austin will be that man. Better than he was before... Stronger... Faster...

Longevity of artificial joints

[spineboy]

Yes, 15 years is the lifetime that we're seeing, on average, but remember that these were put in 15 years ago! The plastics (ultra high molec weight, highly cross linked poly) are supposedly much better now, and should last longer than the 15 years.

Hips and knees are diferent - knees are currently limited to metal on plastic, whereas hips can come in a variety of composites. Recently, metal -metal hips, and ceramic hips have been making a go around - they are supposed to have 10 times less wear than the plastic-metal hips.

TO be honest 15 years is very good. Most people really dont need a total joint arthroplasty (artificial joint) until they are over 50 years of age. One revision surgery should last them until they are around 80 - which is currently a little higher than the average lifespan of most people.

Several factors have an effect on the lifetim of these artificial joints - younger, heavier people wear theirs out faster , than older lighter people. However, being overweight probably was a MAJOR contributing factor for the reason that many people need these in the first place.