Lynxmotion Tech Support

Hi evryone,

Ok... I dunno how to start this...

Let's say I want to create an artificial limb, an arm or a leg.

1. Do you guys know how we could feel the contraction of a muscle. Let's say what's left of the calf msucles contracts, a sensor feels it and contract the muscles that is replacing it on the limb. If that wouldn't work I guess I would have to bring it to a whole new level by connecting directly a sensor to the nerve endings... Do you guys have any ideas?

2. What types of motors, actuators or... whatever I should use. I have these options : Something like the Shadow muscles (basicly it's something you connect to compressed air, and when you open the valve, the compressed air will fill the rubber shell and thus shorten the msucles (and making it bigger at the same time), something like that, maybe I could try to do my own because there expensive. Or seconde, some type of wire that contractes (0.020 inches that contractes with electricity. but like 50-100 of them to create a muscle taht whould be powerful.

Sam

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Sam

What I think you are refering to is EMG sensing. Electronic biofeedback is based on this as well, although the processing tends to be rather simplistic.
Otto Bock, the people who make the C-leg prosthesis, have some products and information here
http://www.ottobockus.com/products/uppe ... orhand.asp

Thanks Eddie,

That link has provided a new idea for me.

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Mike

The robotics nut.

I dont see where there are sensors to coapt the motioin of the body and do the same with the limb...

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Sam

Um, the link was only meant to put you on the path to researching EMG sensing. It is how the myoelectric hands and elbows work, but I don't think it very likely that the Otto Bock website itself will give you much more than enough advertising to get you interested should you have the need. Sorry.

Here's a keyword that'll get you on your way: myoelectric.

It's the basis of the technology that a lot of sensors in the field act on. Google it up.

Six months or so ago I talked to some folks from Hanger Orthopedic Group who use this technology for exactly what you're looking into. Here's the hand they're working on http://www.hanger.com/sections/po/po_ilimb_hand.html

The sensors can only detect larger muscle groups if you're applying them on the surface. The only current way to get really fine muscle control (small muscle bundles actuating the sensors) is to have a trans-dermal implants. I work on the medical device industry and I'll tell you right now trans-dermal is limited to 3 days max by the FDA. So while it's the best resolution, you have to replace the entire sensor network every three days (and relearn how to use it!) so it's been not exactly... useful.

I did try out the large-muscle detectors and just by having the sensors touching my skin I was able to actuate a fully articulated hand. It's pretty amazing stuff.

Good luck,
~Jay

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J. Favreau
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