Bionic limbs integrated to bone, nerves, and muscles | Max Ortiz Catalan | TEDxGöteborg

the idea of restoring the functionality of a limb lost by an amputation with robotic prosthesis or bionic limb has been around for a very long time however you will be amazed on how little prosthetic devices give it to patients today have change in the last decade and this is because a variety of problems and I'm going to tell you how in my group were tackling two of the big ones that is how you attach the prosthetic device to the body and how can the patient control such artificial replacement so let's talk about the first one have you ever had a blister on your feet because of bad fitting shoes and why did that happen you have compression of soft tissue and friction constant friction because of movement sockets the conventional technology to attach a prostitute to the body works on the principle of compressing the stump in order to create enough suspension to keep the prosthesis in place and as you can imagine this is uncomfortable and it can be painful but work for some patients and they learn to tolerate it for some others however this is not good enough and they will choose not to wear a prosthesis at all if you have a short stump there is not enough space for the socket to grabbing so you end up blocking or limiting the range of motion of other joints in this case this patient has a socket and suspension components and he cannot raise his arm higher than that so the cost of wearing a prosthesis come to sacrifice mobility in other joints that otherwise are fully functional a solution from this problem was actually found in Sweden and in Gothenburg with the discoverer of false integration a noise integration basically means that if you put a titanium implant in bone bone cells will grow tightly around and this integration is so strong that you can actually attach the artificial limb directly to the skeleton I have the privilege to work with dr. Khurana mark who is the pioneer of this technology he and our colleagues in Gotham world have spent decades of research developing a treatment that has now been used to treat different amputation levels and is considerably improving the quality of life of hundreds of patients around the world so awesome digression seems to be a technology that's taking care of the first problem now let's talk about the second one how can the patient control the the prosthetic device there was a time when the prosthesis itself was the bottleneck however with the development of electronics motors batteries and materials engineers can now develop very sophisticated hands and arms that not only look really cool but have all the potential to restore the missing functionality if only patients could control that many degrees of freedom or robotic joints there are different approaches to solve this problem one of them is using electrodes on the surface of the skin as you can see around my forearm and then these electrons will pick up the electrical activity of the muscles and then we can use algorithms to the call the B electric signature of each movements if I lose my hand around this height I can still control every finger of the robot I can in a similar way as I will do with my biological hand and we can use other machine learning techniques and control simultaneously different joints of the prosthetic device and if you think about it now that we have this technology to predict the intention of movement we can control a prosthetic device or games entirely with with can motions and this looks like fun well it's actually a lot of fun and that's why we're using it as a tool for neuromuscular rehabilitation and treatment of phantom limb pain a tool we decided to do open source so other people could go and try it and improve it and do something with it so you might think real problem solved we can predict movement we can control the prosthetic device the problem means that this technology works very well in the lab very hard to get it to stable out of it the thing with prosthetic devices is that these are not toys because a toy you can choose one to play with patiently the prosthesis in the morning when they wake up to get dressed to cook to eat to go and work and earn a living and if the prosthesis is malfunctioning is not doing what it's supposed to do they will eventually throw it away it's not uncommon to meet patients that although they have the resources to afford the most expensive prosthesis they will choose not to use anything at all because the functionality support that at the end of the day they're better off without it so functionality reliability easy to use is very important in prosthetic devices and getting signals from the surface of the screen compromises reliability conventional technology uses a socket for suspension surface selectors for control with also integration we move from suspension to fixation which is a lot better mechanical coupling we get rid of the problems related to the socket and although this alone has a lot of advantages we still limit it on control by the surface electrode so what we decided to do in my group is take this technology further and develop it to be a communication port between implanted electrodes and the prosthetic device if you go inside a body you have access to more muscles you have more reliable signals and you have access to nerves nerves carry the control information from every muscle in your limbs but also information from the sensors in your hand back to your brain and very importantly those neural pathways are still there after an amputation this is Magnus is the first patient we treated with this technology we develop electronics to make the system self-contained so he simply means to take the arm pushing close the clamp get mechanical connection and at the same time electrical connection with implanted electrodes so he can control the arm in any position which was previously not possible with surface electrodes this technology has allow us to truly integrate biology and mechatronics this is the first time that the man and the machine have such an intimate connection at many different levels the artificial arm is directly connected to the skeleton and the human control system that is nurse and muscle also have a connection with the artificial device how cool is that thank you but you know this sounds great but what does it mean for the patient well now because the electrode is directly on the muscle he needs to contract it just a little bit and that signal will be enough to drive the prosthetic device and that basically means that he has a more precise control of the hand with very little effort as opposed to surface electrodes where the signal will need to travel between soft tissue fat skin dead skin before he can reach the electrode on the top of the skin another problem with recording from the surface of the skin is the skin moves a lot it's a polarized high impedance interface where electrical artifacts can easily happen because of movement and this basically means that if the patient moves too fast the hand will activate without him wanted to so if he's holding an object in this case an egg and he moves too fast they can will either crush it or let it go and this of course limits the the kind of things you can do with your prosthetic device this doesn't happen with our system is very reliable to motion artifacts and my electric interference so the hand will not open or close without him wanting to do so like now when he's crushing the egg to show that it wasn't a fake one so he can use his hand in any position to do all sorts of you know different stuff and that's something quite amazing from someone with an amputation level like him and all these are cool demos but they translating things that the patient can use his prosthesis for a big problem for Magnus was not been able to use his prosthesis in cold environment and that you know can be a problem living in Sweden so during the winter the skin will get dry and the signals would not translate very well to the surface electrode so he could not use the prosthesis but now since there is no skin interface he can use his prosthesis at minus 30 degree in you know skiing up north in Sweden or when he is in holidays applause 30 in the beach without touching whatsoever the prosthesis of the prosthesis will just work in any environment in any condition all these makes the prosthesis fundamentally more reliable and if it's more reliable it's more useful and since there is no surface components pushing against your skin is also more comfortable he will sometimes leave with the prosthesis we don't know any other patient that does that because if you have the skin components pushing on your body it will be like slipping with your shoes on so this tells us a little bit about you know the integration between man and machine and how this happening at which level this is the first patient in modern times that has been implanted with electrodes permanently and that's actually using them to control a prosthetic device in activities of the daily living and at work he went from working 50 percent to hundred percent because the prosthesis is not a limitation anymore this system has been stable for almost two years now and demonstrating the long-term stability of this system was very important for us because it is that what makes it clinically useful and with that I mean that we can treat patients and they can take this technology home and not only in the lab and that's probably the major contribution of our work to the field this interface is bi-directional by nature and this means that we can stimulate the nerves in order to create the perception of sensations coming from the missing hand very cool as well ah magnet lost his arm over ten years ago and we found that with a single electrical poles deliver to the nerve that used to be connected to his hand he will feel that you are touching him and this is very important it's been stable for several months and the reason why this is important is because today no prosthesis is given to any patient using the real world provide any tactile or proprioceptive feedback but we are also integrated interface we can make this happen outside of the lab where it matters for patients so this is very exciting but the most exciting part is not what we have achieved so far but all the new possibilities we can make with this technology the aim of our group is to to provide a very good mechanical coupling that allow full range of motion for the joints the patient still have and now that we have a permanent connection with the neuromuscular system we can use that to get signals of control from the brain they come down in the nerves and the muscles we can combine them with surgical techniques we can use or decoding algorithms to tell the prosthesis what to do put sensors in the hand so the hand knows when it's touching something what is the position of the hand how much force is put it in an object and translate that would be a neuro stimulation so the patient will feel as you you know as he is touching with his real hand it's a very intuitive control you probably can see there's a lot of different fields involved in this project we have a technical institution we have a medical institution and industrial partner and if you take any of them out of the question this will not happen the engineers cannot do it alone the doctors cannot do it alone and academy by itself would not reach a clinical implementation so we're very fortunate to have this framework of research whether we can make things like this happen so far we've been focusing on the upper limb where our technology equally applies for the lower limb so we can treat patients that we buy will have implanted in the lower limbs as well and we're looking to provide neural control for prosthetic devices at different amputation levels this is my my group patient on the future of bionic limbs thank you

Channel: TEDx Talks

Views: 91,384

Rating: 4.9353275 out of 5

Keywords: Muscle (Anatomical Structure), Nerve (Anatomical Structure), Biomedical Engineering, English, Sweden, ted, ted talks, tedx talks, ted x, Technology, Prosthetic, ted talk, Prosthesis (Medical Treatment), TEDxTalks, Bone (Anatomical Structure), tedx, tedx talk

Id: V4UQU4392wM

Length: 13min 14sec (794 seconds)

Published: Tue Dec 30 2014