Hydraulic/ Pneumatic Prosthesis
edited December 2015 in Prosthetics, wearables, and haptics
I had the idea a while back that instead of using an amputee using a traditional sleeve or an osseointegrated post , one could create a self contained receptacle within the prosthetic that is made for the residual limb.The receptacle could fill the walls and floor with fluid/air and have it perfectly conform to the changing form of ones residual limb, removing the need to visit a prosthetist as often and or having to replace prosthesis as often as well. is this a plausible area of research?
I'm a below knee amputee.
For a socket (the thing your leg goes in) to be comfortable, it has to put very specific load bearing pressures on anatomical areas which can tolerate said pressure, while putting less pressure on anatomical areas which cannot tolerate pressure.
By way of example; the distal end of the medial condyle (of the Tibia) can tolerate a lot of load bearing pressure, whereas the lateral side of the neck of the fibula cannot, because pressure there puts pressure on the fibular nerve which hurts - in my case I have Wallarian degeneration and so can tolerate barely any pressure there.
Additionally, new amputees often have very sensitive distal ends and can hardly weight-bear distally. In the past I could only tolerate about 10lbs and now (3 years post) can tolorate closer to 60lbs.
Owing to different residual limb lengths, circumferences, problematic areas, load bearing distribution needs and the like, I can't feasibly think of a way to make a one-size-fits all prosthesis. You're kind of trying to create a one size fits all shoe, with the added difficulty that feet are built to tolerate the full weight of a foot-having person's body, whereas residual limbs are not.
However, just because I can't think of a feasible way for this type of socket to happen does not mean it can't. This idea could possibly be better suited for upper extremity prosthetic devices, maybe?
Also, in both cases, you have to have a way to keep the prosthesis from rotating. That's done by locking it to the bony anatomy (condyles/epicondyles etc)