The outlook used to be pretty bleak for those who had lost movement in their limbs due to severe nerve damage, but over the last year or so, some incredible advances have been made that are restoring shattered hope for many.
The amazing breakthroughs include spinal cord stimulation that allowed paralyzed men to regain some voluntary control of their legs, a brain implant that enabled a quadriplegic man to move his fingers, and a system that allowed a paralyzed woman to control a robotic armusing her thoughts. Science has definitely been on a roll, but this winning streak isn’t showing any signs of slowing down. Now, the world’s first “bionic reconstructions” have been performed on three Austrian men to help them regain hand function. This technique enabled the newly amputated patients to control prosthetic hands using their minds, allowing them to perform various tasks that most people take for granted.
The men that underwent the procedure had all suffered serious nerve damage as a result of car or climbing accidents, which left them with severely impaired hand function. The nerves that suffered injury were those within a network of fibers supplying the skin and muscles of the upper limbs, known as the brachial plexus. As lead researcher Professor Oskar Aszmann explains in a news release, traumatic events that sever these nerves are essentially inner amputations, irreversibly separating the limb from neural control. While it is possible to operate, Aszmann says the techniques are crude and do little to improve hand function. However, his newly developed procedure is quite different, and is proving to be a success.
Before the men could be fitted with their prosthetic hands, the researchers had to do some preliminary surgical work in which leg muscle was grafted into their arms in order to improve signal transmission from the remaining nerves. After a few months, the fibers had successfully innervated the transplanted tissue, meaning it was time to start the next stage: brain training.
Using a series of sensors placed onto the arm, the men slowly began to learn how to activate the muscle. Next, they mastered how to use electrical nerve signals to control a virtual hand, before eventually moving on to a hybrid hand that was affixed to their non-functioning hand. After around nine months of cognitive training, all of the men had their hand amputated and replaced with a robotic prosthesis that, via sensors, responds to electrical impulses in the muscles.
A few months later, the men had significantly improved hand movement control, which was highlighted by a test of function known as the Southampton Hand Assessment Procedure. As reported in The Lancet, before the procedure, the men scored an average of 9 out of 100, which soared to 65 using the prosthetic. Furthermore, the men reported less pain and a higher quality of life. For the first time since their injuries, they were able to perform avariety of tasks such as picking up objects, slicing food and undoing buttons with both hands.
“So far, bionic reconstruction has only been done in our center in Vienna,” said Aszmann. “However, there are no technical or surgical limitations that would prevent this procedure from being done in centers with similar expertise and resources.”
Seventeen years after losing the use of his hand in a motorcycle crash, Marcus Kemeter volunteered to have it amputated and replaced with a bionic version.
“It wasn’t hard for me to decide to do the operation,” said Kemeter, 35, a used-car dealer in Austria. “I couldn’t do anything with my hand. The prosthesis doesn’t replace a full hand, but I can do a lot of stuff.”
Kemeter’s artificial hand was made possible by a new medical procedure developed at the Medical University of Vienna, which combines reconstructive surgery with advances in prosthetics and months of training and rehabilitation, according to an article published Wednesday in the Lancet, a U.K. medical journal. The researchers performed the procedure on three Austrian men from 2011 to 2014.
The technique, called bionic reconstruction, offers hope for patients like Kemeter who have brachial plexus injuries, which can result in severe nerve damage and the loss of function in the arms.
The nerves of the brachial plexus start in the neck and branch out to control shoulder, arms and hands. They can be damaged in collisions from car and motorcycle accidents, and in sports like football and rugby. In the past, surgical reconstruction for brachial plexus patients could restore some function in their arms but not hands.
The injuries result in an “inner amputation,” permanently separating the hands from neural control, said Oskar Aszmann, a professor of plastic and reconstructive surgery at the Vienna university who is the lead author of the Lancet study.
The damaged limbs “are a biologic wasteland,” Aszmann said in a telephone interview. The solution is transplanting nerves and muscles from the legs into the arm, creating new avenues for signals from the brain.
“We can establish a new signal and we can use these signals to drive a prosthetic hand,” he said.
The process represents a significant step for patients with brachial plexus injuries, said Levi Hargrove, a researcher in prosthetics at the Rehabilitation Institute of Chicago.
“It provides them with an option,” he said. “As mechanical prosthesis become more advanced and more functional, this should only improve.”
The ultimate success of the procedure won’t be known for years and will depend on how often patients use their new hands, said Simon Kay and Daniel Wilks in a Lancet article accompanying the study. Kay is a hand surgeon at the Leeds Teaching Hospital, while Wilks is at The Royal Children’s Hospital in Melbourne.
“Compliance declines with time for all prostheses, and motorized prostheses are heavy, need power and are often noisy,” they wrote.
Kemeter, who lives in the Lower Austrian town of Hollabrunn, damaged his shoulder in a 1996 motorcycle accident. That year, he had surgery that grafted new nerves to his arm, which restored some function to his shoulder and elbow. Over the next decade and a half, his arm withered and atrophied, with his fingers permanently clenched.
“I could feel everything but I couldn’t do anything with the hand,” he said.
In 2011, Aszmann transplanted Kemeter’s nerves from his lower leg and muscle from his thigh to his injured forearm. After waiting three months for the nerves to grow back, Kemeter’s arm was connected to a computer, where he could practice manipulating a virtual hand.
“The brain has forgotten to use the hand,” Aszmann said. “We have to retrain them.”
The next step was connecting the prosthesis to the new nerves, with Kemeter’s biological hand still in place, to train him to use the device. That helps patients with the decision to amputate, Aszmann said.
“When it’s obvious this mechatronic hand can be of great use to them, then the decision to have the hand amputated is a very easy one,” he said. “If I have to convince someone, they’re not a good patient.”
Finally, after the amputation wounds healed and the prosthesis was fitted, the adjustment to the new appendage took only a few days.
“I can do much more than before,” Kemeter said. “Carrying big things, for example, wasn’t possible with only one hand. Now I can do it.”
Related News and Information: Bionic Hands Move Close to Human Control With Sensation of Touch Innovative Prosthetic Arm From Segway Inventor Cleared by U.S. First Bionic Leg to Harness Nerves Allows Mind Control Movement.
Recently I attended an international medical student congress, Medical Student Journal Club – Pro et Contra, which took place on 23. and 24. May 2014 in Ljubljana, Slovenia.
It was a great congress, with a lot of interesting debates preesented by great speakers.
Myself, I have also registred as an active speaker, together with a colleague of mine, Barbara Šijaković. We debated on topic “Reconstructive surgery should focus on development of cadaver body parts transplantation rather than bionic prosthesis implantation“.
Below is a transcript of our debate.
And just for elaboration, the whole keynote was actually made with only videos tu support theses.
Reconstructive surgery should focus on development of cadaver body parts transplantation rather than bionic prosthesis implantation
Luka: Hello, it’s me up here again. So, I thought I could start with an old Marx brothers joke. No wonder it looks like the same room, because it is the same room. Ok, it doesnt go…
Well, since it’s Saturday afternoon and this is the last debate of this congress, we’ll try to be as interesting and short as possible. My name is Luka, on my left a college of mine, Barbara, and, already introduced, our mentor, Nina Suvorov, MD.
Before we actually start with the debate, let us ask you a question. Imagine you’ve lost your hand sometime in the past and now you are presented with two options. Either hand transplantation or bionic prosthesis. Which would you, right now, choose. Would you go for hand transplantation, or would you rather go with a bionic prosthesis. How many of you would choose hand transplantation? And how many bionic prosthesis? Interesting; 60% for bionics and 40% for transplantation. We’ll keep that number in mind.
Barbara: Now, before we begin, let’s clear the terms. Luka, could you tell us what a reconstructive transplant is?
Luka: Thank you, Barbara. A reconstructive transplant, or also called a composite tissue allograft, is an operation that involves transplantation of bone, tissue, muscle and blood vessels. According to WHO “transplantation is the transfer or rather engraftment of human cells, tissues or organs from a donor to a recipient with the aim of restoring function(s) in the body. And in cases when transplantation is performed between different species, e.g. animal to human, it is named xenotransplantation.”
Now, Barbara, would you care to briefly explain what a bionic prosthesis is and how it works?
Barbara: Bionic creativity engineering is basically implementation of biological systems in the developing modern technology. Bionic hand isn’t just the hook. It mimics the real human hand. In some cases bionic hand even superposes human hand, as we shall see later.
There are different bionic prostheses, today I’ll talk about i-Limb Ultra, the one most advanced for now.
Here is how it looks: we can see power button here, the digits are motorized. It’s made out of plastic, titanium and silicone.
And just some mechanical properties…
This is a myoelectric prosthesis, which means it uses electrical sensors to detect contractions in the selected muscles of the residual limb. These contractions are than translated into movement of the bionic hand by a specific algorithms.
Luka: Ok, so which is better? Let’s start with transplantations of the hand. We will focus mainly on the hand, since leg prosthetics are nearly perfect, but with hand it’s different. You have many small and fine movements that are incorporated in every day’s life and you simply cannot function without a hand.
Just some short history for the beginning. The first hand transplant was actually performed in Ecuador in 1964, but the patient suffered from transplant rejection after only two weeks. Then, there was basically a long period of nothing. Up until January 1999. The first successful hand transplantation. Now, you should notice, we are talking about transplantation, not about replantation. The first successful replantation was performed in Shanghai, China, in January 1963.
So, in January 1999 the first person (a baseball player) underwent an operation. This kind of operation is probably one of the longest there is. It takes approximately 12 to 16 hours. In comparison, a typical heart transplant takes 6 to 8 hours and a liver transplant, 8 to 12 hours.
Hand transplantation is an extremely complex procedure, but may not be as difficult as a hand replantation in that a replantation usually involves crushed or mangled bones, tendons, and ligaments.
Barbara: Would you care to elaborate on how this is done? Read more…
When you see a picture of a hand, how do you know whether it’s a right or left hand? This “hand laterality” problem may seem obscure, but it reveals a lot about how the brain sorts out confusing perceptions. Now, a study which will be published in a forthcoming issue of Psychological Science, a journal published by the Association for Psychological Science, challenges the long-held consensus about how we solve this problem. “For decades, the theory was that you use your motor imagination,” says Shivakumar Viswanathan, who conducted the study with University of California Santa Barbara colleagues Courtney Fritz and Scott T. Grafton. Judging from response times, psychologists thought we imagine flipping a mental image of each of our own hands to find the one matching the picture. These imagined movements were thought to recruit the same brain processes used to command muscles to move—a high-level cognitive feat.
The study, however, finds that the brain is adept at decoding a left or right hand without these mental gymnastics. Judging laterality is “a low-level sensory problem that uses processes that bring different senses into register”— a process called binding, says Viswanathan. Seeing a hand of unknown laterality leads the brain to bind the seen hand to the correct felt hand. If they are still out of register because of their conflicting positions, an illusory movement arises from the brain’s attempt to bring the seen and felt hand into the same position. But “this feeling of moving only comes after you already know which hand it is.”
In the study, participants couldn’t see their own hands, which were held palm down. They saw hand shapes tilted at different angles, with a colored dot on them indicating a palm-up or down posture. One group of participants saw the shape first and then the dot; and the other, the dot first. Participants in both groups put the shape and dot together mentally and indicated which hand it was by pushing a button with that hand. However, when the shape and dot were shown simultaneously, participants in the first group felt movements of their right hands when seeing a left hand and vice versa; the other group always felt a movement of the correct hand. This behavioral difference (which experimenters gleaned from response time) was due to differences in participants’ perception of the seen hand—establishing that an earlier sensory process made the decision.
In a second experiment, participants were told which hand it was and had to judge whether its palm was down or up, indicating their answer with one hand only. This time, the illusory hand-movement occurred only when the seen hand-shape matched that of the participant’s own palm-down responding hand, but not otherwise. Even though no right/left judgments were required, the response was dominated by an automatic binding of the seen and felt hands, and the illusory movement followed, says Viswanathan.
The study helps us understand the experience of amputees, who sometimes sense an uncontrollable itch or clenching in the “phantom” body part. Showing the opposite hand or leg in a mirror allows the patient to “feel” the absent limb and mentally relieve the discomfort—a “binding” of vision and feeling.