Mind-controlled prosthetic hand for amputees via RPNI neural interface

It brings you back to a sense of normalcy. It's like you have a hand again. Advanced prosthetic hands on the market can do lots of things These are beautiful prosthetics with incredible capabilities, but we've had no way to control them. To get that kind of control, you really have to go to the nerves The problem with most of the technologies we have is that the signals are really tiny.

 You have tiny little peripheral nerve signals and you have noise in those signals that's about the same size. So when you try to hear what a peripheral nerve is saying you actually can't hear it. We designed a way to connect up with the peripheral nerves with a piece of muscle and then what happens is when a tiny little peripheral nerve signal comes down the nerve, it goes into the muscle and it becomes a huge muscle signal. 


We've now seen to my knowledge the largest voltage recorded from a nerve compared to all previous results. That makes these signals big enough that we can record them and interpret them for controlling a prosthetic hand. 


It brought back into my mind the thought of: "well, if I had something like this I could actually be out working without risking hurting myself." I think it's a really good step into the future. It's a good way to move forward for not only me but for other people. You can make a prosthetic hand do a lot of things but that doesn't mean that the person is intuitively controlling it. So the difference is the person just thinks about moving. 

This worked on the very first time we tried it. So now we can access signals associated with individual thumb movement, multi-degree-of-freedom thumb movement, individuated fingers, and this opens up a whole new world for people who are upper-limb prosthesis users.

Open-source bionic leg aims to rapidly advance prosthetics


 You want to get something out of a lab and help people with disabilities, it doesn't look like an academic publication, it looks like access. And that's what we're going for, we're giving access to people.... to anybody. 


Control is the biggest problem affecting the clinical impact of robotic legs today but each researcher develops their own hardware first so everybody's testing on a different system. So when people are publishing, "hey look at this control strategy I could do this", very difficult for people to replicate it because they don't have that hardware.


 We have created opensourceleg.com to kind of unite this fragmented field of control prosthetic legs. So there's a bill of materials which explains like where to get them to the vendor and a price. There's all the solid models which are like how you would have it machined. Solid model files are all downloadable. 

There's also videos on how to go step-by-step through the assembly process. I mean, the website is open to anybody. We already, right now, have five collaborators who are using these to test their control strategies. So like within a very very small amount of time, we've got a lot of impact and a lot of interest.

History of Prosthetics

A prosthesis is much more than a medical device, it also completes a wearers sense of wholeness, it gives emotional comfort. And so the history of prosthetics isnt just about the advancement about medical science, its a story of human beings who miss an essential part of their self. It is the story of human beings struggling to regain a wholeness they have tragically lost. The earliest known prosthesis is not a leg, arm, or even a fake eye. Its a toe. A big toe, beloningen to an egyptian noblewoman living around 3.000 years ago. Now, this may seem odd at first. A person can technically live without a big toe. But to Egyptian society at the time, your big toe was culturally important.


 To egyptians, wearing sandals was an important tradition, important enough to warrant the construction of this early prosthetic. This big toe shows that a prosthetic is as much about function as identity. For the next big revolution in prosthetics, we have to go to ancient Rome, during the Second Punic War. General Marcus Sergius lost his right hand on the battlefield. This would generally mean youre unable to enter another battle, as he needed two hands to hold a sword and shield. But he instead had an iron hand fashioned for him, so he could still hold up his shield, so he could still perform his function, so he kept his identity as a general.

 With his prosthetic, Marcus Sergius would continue to serve in a long military career. Iron hands, such as the one the roman general wore, would continue to be used for thousands of years, up until the late middle ages. Knights who lost their hand would often purchase an iron prosthetic. It could be attached to the armour or to the limb with leather straps and were handcrafted to fit the individual wearer. Usually knights employed the same blacksmith for their armour as for their prosthetic. While these hands could be used to carry a shield, their main purpose was to hide the fact a person was disfigured. It was much more a personal and cultural tool, rather than a practical one. It allowed the wearer to retain his identity as a knight and warrior. 


But such Iron prosthetics were only for the wealthy, peasants had to do with crutches. But outside the battlefield, there was the wooden peg and a hook hand. Yes. They are real. While fiction has made them the staple of pirates, and sure some pirate amputees probably did have them, the were actually not all that common. To attach such peg you would need a surgeon who would be able to cut the limb properly. But surgeons were uncommon on ships. So the vast majority of pirates did not have hook hands or peg legs. But lets consider the fact that iron hands, wooden pegs, and hooks hands were used for thousands of years, that they were used from the Roman Empire all the way to the end of the Middle Ages, showing just how slowly medicine progressed. Unlike amputations (see my video on that by pressing the link in the top-right corner), unlike amputations, where advancements were made incrementally, prosthetics advanced far slower. The next major advances would come with a doctor named Ambroise Paré in the 16th century. 


He created the hinged prosthetic hand and a leg with a locking knee joint. This allowed the wearer to bend their knee and elbow, allowing them to sit normally. If you wanted to stand up again, you could lock the knee and arm in place so it wouldnt bend anymore, allowing you to walk more normally. These were invented in the 16th century. But what is shocking is that this invention is still common in modern prosthetics, even though they were invented nearly 500 years ago. Up to modern day, these inventions saw only small improvements. Although this is not to say that the advancements were negligible, improvements such as a prosthetic attached through suction, aluminum prosthetic so the wearer wouldnt have to drag a heavy metal leg or arm around, and the most amazing of them all: a hand which could be locked into different positions to allow the user to hold objects in their prosthetic hand, such as a fork for eating.

 But it would take until 1861 for the next major advancement: The Hanger limb, invented by the first amputee of the United States civil war, James Hanger. James prosthetic limb was noiseless but very similar to the one of Ambroise Pare. What made this leg so different was its affordability. This is the first prosthetic leg which was available to tens of thousands of US soldiers who lost their leg during the Civil War. James Hanger even founded a company which produces prosthetic limbs to this day, named Hanger Incorporated. 


And while modern medicine was up and coming and advanced the field of amputations tremendously, prosthetics did not see much improvement until finally in the 1970s, inventor Ysidro Martinez made a huge impact on the history of prosthetics, when he developed a low-limb prosthesis. His prosthesis was revolutionary because its the first which did not try to replicate the motions of the human body. Instead, his artificial limb focusses on gait, or walking pattern, and reducing friction. And this is where history meets today. 

The story of creating artificial limbs is far from over. Scientists today are still working on improving the lives of amputees. From controlling the artificial limb with your brain, to allowing the patient to feel with their prosthetic limb, to regrowing the limb all-together. 

It really does appear that amputations will no longer be a problem in the future, that people will be able to feel as though they are still whole, where a persons sense of identity is no longer impaired, a future where losing a limb will be a temporary loss and people can keep living life to their fullest. If you liked this video, give it a thumbs up. 

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