New Prosthetic Legs Let Amputees Feel Their Foot and Knee In Real-Time

In a paper published in Nature Medicine today, researchers led by ETH Zurich describe how they modified an off-the-shelf prosthetic leg with sensors and electrodes to give wearers a sense of knee movement and feedback from the sole of the foot on the ground. Engadget reports: The researchers worked with two patients with above-the-knee, or transfemoral, amputations. They used an Ossur prosthetic leg, which comes with a microprocessor and an angle sensor in the knee joint, IEEE Spectrum explains. The team then added an insole with seven sensors to the foot. Those sensors transmit signals in real-time, via Bluetooth to a controller strapped to the user's ankle. An algorithm in the controller encodes the feedback into neural signals and delivers that to a small implant in the patient's tibial nerve, at the back of the thigh. The brain can then interpret those signals as feedback from the knee and foot.

The modified prosthetic helped the users walk faster, feel more confident and consume less oxygen -- an indication that it was less strenuous than traditional prosthesis. The team also tested activating the tibial nerve implant to relieve phantom limb pain. Both patients saw a significant reduction in pain after a few minutes of electrical stimulation, but they had to be connected to a device in a lab to receive the treatment. With more testing, the researchers hope they might be able to bring these technologies to more amputees and make both available outside of the lab.

"Gentlemen, we can rebuild him..."

[Tablizer]

https://www.youtube.com/watch?... [youtube.com]

Bluetooth?

[TFlan91]

What?

Why do I need Bluetooth for communication between sensors on the bottom of a fake foot and the computer just a few inches above them?

This is just reckless.

Re:Bluetooth?

[fahrbot-bot]

Why do I need Bluetooth for communication between sensors on the bottom of a fake foot and the computer just a few inches above them?

I imagine it's because the prosthetic is detachable and the (presumably, low-power) implant is, well, implanted under the skin. In either case, wires would probably be inappropriate and a proximity antenna taped to the thigh would probably be cumbersome.

Re:

[bugs2squash]

I would have thought that latency would be an issue - I wonder if the brain can adapt to that, or what the typical latency of the natural nervous system is - reaction time I presume

Re:

[omnichad]

AptX's low latency mode for audio can get down to 1ms. A custom-designed protocol with lower bandwidth requirements could possibly get lower. If it's coming in continuously, I imagine that it's just a slight change in reaction time and probably wouldn't feel noticeably different.

Re:

[MobyDisk]

Related anecdote: I can't find the article, but I read that the speed of the electrical signal traveling down a pitcher's arm from their brain to their hand takes so long that throwing a ball is a closed-loop process. By that I mean, it is not that the brain receives a signal indicating that the arm has reached a certain position, and then it sends the signal to the hand telling it to release the ball. It is not possible for the signal to get from arm to brain then to hand fast enough. The brain must ant

Impressive

[110010001000]

That is a pretty impressive technological feat. I took an arrow to the knee once and this might benefit me.

Re:

[Rosco P. Coltrane]

I think you would be better helped if you had it removed.

Re:

[iggymanz]

I know a way you can make your knee exactly like the other one

do you have a friend into archery?

Great!

[Rosco P. Coltrane]

Soon amputees will be able to stub their toes like the rest of us.

Re:

[bozzy]

And those with kids will reclaim the joy of stepping on Legos in the dark.

Re:

[WallyL]

Stubbed-toe equality, ADA-style!

Batch Mode

[theshowmecanuck]

I'd rather feel my feet in batch mode.

Feel them in real time?

[mandark1967]

So would a large glass jar filled with Formaldehyde...