 introduction and thank you very much for coming. I'm Siwei, I am a medical engineer and post-doc researcher working at TU Munich and as you just heard, in my free time I'd like to say it's my band. Now let's get to work. The topic of my talk tonight is copy of implants, also known as artificial hearing. Hearing has been an important part in our lives. Every day we get to hear sounds like speeches, music. The key organ that is responsible for our hearing is the coplia, which is the snare-like structure shown in the picture here. And then there is the auditory nerve, which is the central nerve responsible for hearing that goes from within the coplia all the way to the brain. We know that the sound is basically vibration, so when the sound comes into the ear canal, it vibrates the ear drums and then gets transmitted by the ear bones all the way into the coplia. There is some specific cells called the hairstyles. They sense the vibration and then they activate the auditory nerve to create electrical impulses with a shape like this. The activation of auditory nerve within the coplia is dependent on the frequency of the sound, also known as the pitch of the sound. And here is a video that's going to show you the difference in terms of the location depending on frequency. So note that for each individual frequency there's only a narrow band of the auditory nerve in the coplia gets activated. So after the electrical impulses is generated after the activation of auditory nerve, the electrical signal gets transmitted into the brain via the nerve. The brain receives the signal interpreted and then we hear. So therefore the hairstyles are very important because it's responsible for converting the mechanical vibration into electrical signals. Unfortunately it's very fragile and it's highly susceptible to noise damage such as loud music in the nightclubs. And unfortunately unlike many other cells in our body, once they die, they won't recover, they'll just stay there. And that leads to permanent ear loss. And so we will say since the basis of hearing is electricity, then what if we bypass the dead hairstyles and directly activate the auditory nerves with a small amount of electricity from some electronics? Will that be able to help to restore hearing? That is the idea behind the coplia implant. So here is a picture of a person wearing the coplia implant and here is how it looks like on the inside. Again we see our old friend the coplia and then also the auditory nerve. We notice that the coplia implant has two parts, the external and internal parts. The internal parts of the coplia implant include the microphone and speech processor that goes behind the ear and also the transmission coil goes on the skin or on the hair depending on if the person has hair or not. And then the internal part includes the receiver and stimulator goes under the skin and an array of 12 to 20 electrodes that goes microelectricals that goes inside the coplia. So when the sound comes in, gets picked up by a microphone and converted into digital signal by the speech processor. And then the signal gets transmitted by a transmission coil into the receiver. After the signal being interpreted, depending on the property of the sound, such as frequency, the stimulator sends out a small amount of electrical current through the microelectro array to activate auditory nerve within the coplia. Again it creates electrical impulses which gets carried through the nerve into the brain. Coplia implants has been considered as the most successful neural implants nowadays. It has been capable of restoring 30% of hearing, especially speech understanding for more than 500,000 recipients. So you may wonder how the sound would sound like to the coplia implant recipients. So, I was playing an audio speech at the beginning of the presentation, which feels like a movement dem Alterweicht durch jede Lebensstufe, durch jede Weisheit auch um jede Lebensstufe outside. And here is a comparison that assimilates how that audio would sound like to the coplia implant recipients. So as we can imagine the excitement for the recipients, but they found that they are able to hear. But at the same time, you also notice that there was a lot of noise in the audio and how the noise was distorting the original sound. So it would be quite difficult for the recipient to understand what they hear, especially after a long time of deafness. And they need a certain amount of time of training to learn to hear again. And that's what we call the auditory rehabilitation. So as we would have figured that the coplia implant nowadays is far from being perfect, one of the major challenges is that it's difficult for the recipients to differentiate five pitches. And therefore it's difficult for them to understand tonal languages. It's difficult for them to understand the emotions in the speech because it's normally related to the pitch in our voice. For example, there's normally a difference in meaning between when I say, ah, the coplia implant recipients won't be able to detect it. And next is that it's difficult, it's almost impossible for them to hear music. Again, I'm going to play a comparison of two audios. One is the audio of the music that we are at the beginning. There is how it would sound like to the coplia implant recipients. Apparently, there is still a lot of room for the coplia implant to develop. For the last four years, I've been working at Tumile to develop computer models of coplia implant. And the model is based on this full set of medical images. Sorry, the models of course are to help develop the technology. Anyway, the computer model on the full set of medical images that shows the detail and complete geometry of the coplia and the surrounding structure. And the images was having such a high resolution that it was capable of showing a small object as small as 6 micrometer, that is 0.0006 meter. This video is going to show you how the computer model looks like. First, so this transparent object is the fluid inside the coplia. The semi-transparent object is the microelectro array and with these shiny metal plates representing the microelectros, they are altogether 12 microelectros in this model. And this yellow object is the auditory nerve. And from here you can see that the nerve goes from within the coplia model way out and leads to the brain, this side. And this model was in that inside scale of a human head model, that there was a lot of noise in what coplia implant was doing here. And now let's talk about why. So here is the stimulation results from the coplia model that shows the activation pattern of the auditory nerve if the electrical current is delivered from each of the 12 electrodes individually in a model. And we notice that for a single electrode, and also the redder the area is, the higher the possibility of the auditory nerve gets activated. So we notice that for a single electrode, a large nerve gets activated. And it's even reaching into the area that was supposedly responsible for other electrodes. And we notice that from one of the videos that parallel band of the auditory nerve is supposed to be responsible for one single frequencies, which means that one coplia implant electrode is going to activate a wide area that is supposed to be responsible for a wide range of frequencies. And since the noise that we just heard is practically made of a huge range of frequencies, which means that the noise is practically unavoidable in current coplia implants devices. And therefore we need to develop the coplia implant by finding a better way to activate the auditory nerves. And I hope that I'll be able to tell you what those methods will be very soon with the health of money can be a lot of. So in summary, what we learned in the last 15 minutes is that coplia implant works by activating the auditory nerve directly with a small amount of electrical current. It's capable of restoring certain degree of hearing, especially speech understanding. Despite that they're still facing a lot of challenges, such as the noise problem, they're still considered as one of the most successful neuro implants nowadays. And hopefully with the advancement of this technology, it's going to be able to restore full hearing for the coplia implant recipients. That's the end of my talk. Thank you very much. Thank you for those who like this. Thanks for the presentation. I was wondering, with the development of technology, because the idea would be to extract these implants when we develop your implants. Is there any risks? Has that already been done, extracting all the implants? So the question is that, is there going to be any risk for the implant removal? Very much the same risk as you would do any surgery is the anesthesia and also the potential of getting an infection. Otherwise, removing itself would have much problem. Thank you for your talk. I wanted to ask you, did you hear about the latest news? The US American University has developed a kind of community which recreates the hair in the ear. So you won't need any coplia anymore. They have made some researches on mice which work well and now they are trying to implement it on human beings. And this would be the, this was published about three or four weeks ago. So it won't be very interesting to say something to this. What is the status of this? Okay, so your question is about what would happen to this technology if we were able to re-grow the hair cells in the future. Because that's the goal and you can hear again. Yes, for sure, definitely. I mean this technology and also as saying as other types of neuro implants such as retinal implants and also cortical implants, they are the purpose of these implants is to restore the function. If we are really able to re-grow like every part in our body, then of course there is no need for any other type of implants. But for the moment I would say that it is even necessary to develop the neuro implants because right now as people say it's only in animal experiments and it would also be quite difficult to, it firstly also depends on what animals are they using because some animals today it's actually easy to control where the drug will go inside the cochlear, but some will be different as for example in human that the cochlear is being back where it did inside the skull. They are in the status, they are asking for people who would like to join this research So in the US human beings to try out the nerve you have is very much so it's quite fun so I hope it will be further than what I'm saying. So let's not be wait for your evidence. We have any tips if we talk to a person with cochlear implant fate and how can I speak or how I have to speak to the person understanding that is there any trick? The question is is there any trick to speak to the cochlear implant recipient so that they can better understand. So I mean the purpose of this implant is so that they are they're capable of communicating just as normal also although of course I mean one thing is that do not speak the thing under very normal situation because it would be difficult for them to understand why it's you know just make sure that he's wearing the so as you mentioned there was a 12-odd term used in this implant right? 12-odd term right? It's normally 12 to 20 or more if you add number of electrodes in this case could you put that here? Yes in a sense but at the same time it will also the noise will still be there like you can probably recruit you can probably stimulate some you can have some major frequency they don't want at the peak area where you see the most red area but at the same time it's still going to be very loud so the noise will still be there just think about the OT like if you turn it louder the noise is still there. Tencent then what is your approach to increase resolution and decrease this noise to develop a better energy of the implant? That could be a little bit more of little bit complicated to explain in this one minute so okay it's just mainly to change the so right now what I just showed you earlier is that they're using the ground using the receiver problem as the ground and then model polar stimulation from each of the electrodes individually but we can somehow carry by polar stimulation within just using the cochlear implant electrodes like within the cochlear so that to make it more full