Prosthetic limbs are necessary, and with the recent advancements in technology, they are becoming more and more developed. There will always be injuries or accidents that will create a need for a prosthetic limb; the important thing is that these limbs are becoming so advanced that they might soon be able to mimic the limb they are replacing completely.
They are becoming computerized, they can be controlled by our brains, and they can even send signals to our brain so that we feel. At this point, as good as these advanced prosthetic limbs are, due to their complexity, some people still opt for simpler devices.
The biggest issue here is the part with feeling various sensations. We feel our wrists flexing as we exercise without the need to look at it. When we have an artificial one, we have to observe it continuously to see what it is doing. And this is a big issue that the team from MIT is trying to rectify. They are trying to bring back sensations to amputees.
Another big issue here are the amputations themselves. As much as the prosthetics themselves have gotten better, the procedure of removing the limb has stayed pretty much the same as it was back during the Civil War. The first thing the team needs to change is the limb removal procedure. The typical amputation goes like this: Doctors slice through the limb, cutting through bone, muscle, and nerves. They leave some muscle for cushioning, and that is it. The pain from an amputation comes from the nerves swelling as they do not have any organ to stimulate. This procedure also weakens the electrical signals coming from the muscle, and that is why amputees have trouble with controlling their new bionic limbs.
Another thing to think about is the fact that muscles come in pairs – pairs that do opposite things. One flexes the muscle while the other relaxes it. The amputation usually breaks this pairing. One thing the scientists are considering is recreating muscles that might make the limbs feel more natural. This could also help the amputee have a better sense of what the limb is doing, without the constant need to observe it.
This was tested on seven rats. The researchers took two muscles with nerves removed, paired them and then grafted them onto the legs of a rat. They then took two nerves that flex and extend muscles and attached them onto the muscle grafts. When stimulating the muscles in order for them to contract, the scientists noticed that the muscle automatically sent signals to the brain that it is being stretched.
These results showed that artificial muscle pairing does allow the flow of information to and from the limb. This means that the electrical stimulation in a prosthetic limb might be able to provide the necessary information about the limb’s location and the sensation in it to the brain.
So, it is imperative that we preserve the amputated limbs for them to be used to create bionic prosthetics.
These findings mean that it might be possible to revise someone’s amputation take muscles from another part of their body and recreate the ones that have been amputated. That is why scientists are pushing for this procedure to be approved from the ethical board. The method itself is low risk, and if it is unsuccessful, it should be similar to conventional amputations.
Muscles are much better at communicating with synthetics; the bigger problem are the nerves which reject synthetics much more easily. If the prosthetics were to be grafted from amputated limbs, it would be much easier for the body to accept them.