From a purely technical point of view, we are quite well advanced in bionics. We are getting a lot of progress, better computer technologies, better battery powers. But our benchmark is the performance of healthy people. And from that point of view, we are still far away, says Robert Riener in conversation with Maciej Chojnowski
Maciej Chojnowski: During your Infoshare talk you used the term cyborg, which has specific connotations in popular culture. People usually associate it with monstrous creatures from science fiction movies that have better capabilities than regular people. Why then use it in a scientific context of bionic prostheses that help people with disabilities?
Robert Riener*: Actually I was using it more to satisfy the expectations of the audience and the organizers. But I do not like it so much either, because it’s typically, as you said, a bad guy in the movies, or something synthetic, less human. That’s why I prefer to speak just about humans with assisted or bionic devices. I hope that in my talk this negative connotation of cyborgs was not too present.
At the conference you gave different examples of tools being able to help the deaf, blind or people who lost their limb. You also mentioned limitations of those inventions. How advanced are they now and what are their limitations?
From a purely technical point of view, we are quite well advanced. We are getting a lot of progress, better computer technologies, better battery powers. But our benchmark is the performance of healthy people. And from that point of view, we are still far away.
The main limitations of the assisted devices are mostly due to interfacing problems. To get the signal from the device to the human and answer back from the human, like getting motion intension into the device – that’s a challenge because you have to get in contact with the body, or put something into the body, which is surgically challenging.
It is also challenging from the technical point of view, because you get connective tissue around the electrodes, which is affecting the function of the devices.
What is more if you want to wear a device all day long, which is a typical case, then you need to have the systems lightweight and the battery power must be enough. Especially to produce movement, you need a lot of power. And these devices work just for a few hours, which is not enough. If you want them to work for one day long, you need to recharge them. It’s another limiting factor.
Quite a few challenges.
And then if we would sort this out, there is yet another obstacle. If you move your finger, there are thousands of motor units active in some dozens of muscles, and millions of receptor cells which give sensory signals from the fingers back to the brain. At the moment we do not get this sort of high resolution in technical components.
It’s the limitation of the artificial materials we have. And we can only overcome it if we get to biological materials. So the future solutions will be more biological than purely technical.
The problems with perception are not limited to the sense of touch. They appear also with regard to seeing and hearing. In your talk you discussed cochlear and retina implants. People who use them still cannot listen to music or see things in normal resolution. All they see is just a couple of pixels, right?
Yes. The sensory protheses that exists, like prothesis to regain hearing functions (cochlear implants) or prothesis to regain seeing functions (retina implants), are limited because they are too bulky. We need electrodes to artificially stimulate the central nervous system in the human body. And the electrodes we are using are in the range of a millimetre down to maybe 10 micrometres, which is more from technical point of view, but which are still much larger than our nerve cells and receptor cells are.
Of course, this technology can get hacked in different ways. But for me saying that hacking is a problem and then we should not use or develop these systems would be wrong
This means that the number of channels we can produce in the artificial device is much lower than the number of channels we have in the human body. So, retina has millions of photoreceptor cells, which can see colours and black or white. The best chip you get now has about a hundred of channels, which is still much less than the natural resolution that we have in our retina.
It’s similar with the hearing function. The best systems have 30 electrodes so we have 30 bands of sound frequencies in these artificial hearing devices. And that’s nothing compared to the human hearing system which has a continuous space of frequencies. And our perception can partly compensate for this lack by some level of imagination but the technical system is down scaled too much compared to biological system.
Are there any security issues as far as bionic organs are concerned? In other words, can humans using bionic protheses be hacked in some way?
Of course, this technology can get hacked in different ways. And since we are getting more and more links in our society by mobile systems, wireless internet networks, it increases the number of possibilities how to hack such systems.
But for me saying that hacking is a problem and then we should not use or develop these systems would be wrong. Because we can always harm other people. So we should rather educate our society so that they use such technologies in a responsible way.
To conclude I would like to go back once again to cyborgs. As a scientist, you help people with disabilities. But what do you think of using this technology to enhance people who don’t suffer from any kind of disability?
In the long run, this aspect is certainly problematic, but in the short run, I don’t see a big problem. In the short run we have always three important questions.
First, when we develop new technology which enhances our body, we have to check if the technology is safe, if it doesn’t harm us or our human environments. Second, we have to be sure that we do not force people to use it. And third, we have to be sure that it’s affordable for the people.
So, if these three conditions are taken into account, then I don’t think it’s a problem if we have new technologies which enhance ourselves, which we have already anyway. I cannot live anymore without my mobile phone nor drive my car without navigation system. I’m already addicted to mobile technologies.
However, in the long run, we could think that if we combine our bodies and technology components, they will get better than our natural legs, arms, or hands. Then the question is, should we get rid of biology components, which we got from evolution or maybe from God.
This question gets a bit more tricky, maybe gets a religious dimension, and I do not have an answer for this yet. But most of the technologies we have nowadays are not too close to this situation yet.
*Robert Riener is full professor for Sensory-Motor Systems at the Department of Health Sciences and Technology, ETH Zurich, and full professor of medicine at the University Hospital Balgrist, University of Zurich. His current research interests involve human motion synthesis, biomechanics, virtual reality, man-machine interaction, and rehabilitation robotics. He is the initiator and organizer of the Cybathlon – a unique championship in which people with physical disabilities compete against each other to complete everyday tasks using state-of-the-art technical assistance systems. He has published more than 400 peer-reviewed journal and conference articles, 20 books and book chapters and filed 24 patents. He has received 22 personal distinctions and awards including the Swiss Technology Award in 2006, the IEEE TNSRE Best Paper Award 2010, the euRobotics Technology Transfer Awards 2011 and 2012, the European Excellence Award 2017 and the Yahoo Sports Technology Award. In 2018 he obtained the honorary doctoral degree from the University of Basel.
We would like to thank the organizers of Infoshare for their help in arranging the interview with Robert Riener.
Przeczytaj polską wersję tego tekstu TUTAJ