Tag Archives: Sahlgrenska University Hospital

Living with a mind-controlled prosthetic

Leave a reply

This could be described as the second half of an October 10, 2014 post (Mind-controlled prostheses ready for real world activities). Five and a half years later, Sweden’s Chalmers University of Technology has announced mind-controlled prosthetics in daily use that feature the sense of touch. From an April 30, 2020 Chalmers University of Technology press release (also on EurekAlert but published April 29, 2020) by Johanna Wilde,

For the first time, people with arm amputations can experience sensations of touch in a mind-controlled arm prosthesis that they use in everyday life. A study in the New England Journal of Medicine reports on three Swedish patients who have lived, for several years, with this new technology – one of the world’s most integrated interfaces between human and machine.

See the film: “The most natural robotic prosthesis in the world” [Should you not have Swedish language skills, you can click on the subtitle option in the video’s settings field]

The advance is unique: the patients have used a mind-controlled prosthesis in their everyday life for up to seven years. For the last few years, they have also lived with a new function – sensations of touch in the prosthetic hand. This is a new concept for artificial limbs, which are called neuromusculoskeletal prostheses – as they are connected to the user’s nerves, muscles, and skeleton.

The research was led by Max Ortiz Catalan, Associate Professor at Chalmers University of Technology, in collaboration with Sahlgrenska University Hospital, University of Gothenburg, and Integrum AB, all in Gothenburg, Sweden. Researchers at Medical University of Vienna in Austria and the Massachusetts Institute of Technology in the USA were also involved.

“Our study shows that a prosthetic hand, attached to the bone and controlled by electrodes implanted in nerves and muscles, can operate much more precisely than conventional prosthetic hands. We further improved the use of the prosthesis by integrating tactile sensory feedback that the patients use to mediate how hard to grab or squeeze an object. Over time, the ability of the patients to discern smaller changes in the intensity of sensations has improved,” says Max Ortiz Catalan.

“The most important contribution of this study was to demonstrate that this new type of prosthesis is a clinically viable replacement for a lost arm. No matter how sophisticated a neural interface becomes, it can only deliver real benefit to patients if the connection between the patient and the prosthesis is safe and reliable in the long term. Our results are the product of many years of work, and now we can finally present the first bionic arm prosthesis that can be reliably controlled using implanted electrodes, while also conveying sensations to the user in everyday life”, continues Max Ortiz Catalan.

Since receiving their prostheses, the patients have used them daily in all their professional and personal activities.

The new concept of a neuromusculoskeletal prosthesis is unique in that it delivers several different features which have not been presented together in any other prosthetic technology in the world:

[1] It has a direct connection to a person’s nerves, muscles, and skeleton.

[2] It is mind-controlled and delivers sensations that are perceived by the user as arising from the missing hand.

[3] It is self-contained; all electronics needed are contained within the prosthesis, so patients do not need to carry additional equipment or batteries.

[4] It is safe and stable in the long term; the technology has been used without interruption by patients during their everyday activities, without supervision from the researchers, and it is not restricted to confined or controlled environments.

The newest part of the technology, the sensation of touch, is possible through stimulation of the nerves that used to be connected to the biological hand before the amputation. Force sensors located in the thumb of the prosthesis measure contact and pressure applied to an object while grasping. This information is transmitted to the patients’ nerves leading to their brains. Patients can thus feel when they are touching an object, its characteristics, and how hard they are pressing it, which is crucial for imitating a biological hand.

“Currently, the sensors are not the obstacle for restoring sensation,” says Max Ortiz Catalan. “The challenge is creating neural interfaces that can seamlessly transmit large amounts of artificially collected information to the nervous system, in a way that the user can experience sensations naturally and effortlessly.”
The implantation of this new technology took place at Sahlgrenska University Hospital, led by Professor Rickard Brånemark and Doctor Paolo Sassu. Over a million people worldwide suffer from limb loss, and the end goal for the research team, in collaboration with Integrum AB, is to develop a widely available product suitable for as many of these people as possible.

“Right now, patients in Sweden are participating in the clinical validation of this new prosthetic technology for arm amputation,” says Max Ortiz Catalan. “We expect this system to become available outside Sweden within a couple of years, and we are also making considerable progress with a similar technology for leg prostheses, which we plan to implant in a first patient later this year.”

More about: How the technology works:

The implant system for the arm prosthesis is called e-OPRA and is based on the OPRA implant system created by Integrum AB. The implant system anchors the prosthesis to the skeleton in the stump of the amputated limb, through a process called osseointegration (osseo = bone). Electrodes are implanted in muscles and nerves inside the amputation stump, and the e-OPRA system sends signals in both directions between the prosthesis and the brain, just like in a biological arm.

The prosthesis is mind-controlled, via the electrical muscle and nerve signals sent through the arm stump and captured by the electrodes. The signals are passed into the implant, which goes through the skin and connects to the prosthesis. The signals are then interpreted by an embedded control system developed by the researchers. The control system is small enough to fit inside the prosthesis and it processes the signals using sophisticated artificial intelligence algorithms, resulting in control signals for the prosthetic hand’s movements.

The touch sensations arise from force sensors in the prosthetic thumb. The signals from the sensors are converted by the control system in the prosthesis into electrical signals which are sent to stimulate a nerve in the arm stump. The nerve leads to the brain, which then perceives the pressure levels against the hand.

The neuromusculoskeletal implant can connect to any commercially available arm prosthesis, allowing them to operate more effectively.

More about: How the artificial sensation is experienced:

People who lose an arm or leg often experience phantom sensations, as if the missing body part remains although not physically present. When the force sensors in the prosthetic thumb react, the patients in the study feel that the sensation comes from their phantom hand. Precisely where on the phantom hand varies between patients, depending on which nerves in the stump receive the signals. The lowest level of pressure can be compared to touching the skin with the tip of a pencil. As the pressure increases, the feeling becomes stronger and increasingly ‘electric’.

I have read elsewhere that one of the most difficult aspects of dealing with a prosthetic is the loss of touch. This has to be exciting news for a lot of people. Here’s a link to and a citation for the paper,

Self-Contained Neuromusculoskeletal Arm Prostheses by Max Ortiz-Catalan, Enzo Mastinu, Paolo Sassu, Oskar Aszmann, and Rickard Brånemark. N Engl J Med 2020; 382:1732-1738 DOI: 10.1056/NEJMoa1917537 Published: April 30, 2020

This paper is behind a paywall.

Man with world’s first implanted bionic arm participates in first Cybathlon (olympics for cyborgs)

Leave a reply

The world’s first Cybathlon is being held on Oct. 8, 2016 in Zurich, Switzerland. One of the participants is an individual who took part in some groundbreaking research into implants which was featured in my Oct. 10, 2014 posting. There’s more about the Cybathlon and the participant in an Oct. 4, 2016 news item on phys.org,

A few years ago, a patient was implanted with a bionic arm for the first time in the world using control technology developed at Chalmers University of Technology. He is now taking part in Cybathlon, a new international competition in which 74 participants with physical disabilities will compete against each other, using the latest robotic prostheses and other assistive technologies – a sort of ‘Cyborg Olympics’.

The Paralympics will now be followed by the Cybathlon, which takes place in Zürich on October 8th [2016]. This is the first major competition to show that the boundaries between human and machine are becoming more and more blurred. The participants will compete in six different disciplines using the machines they are connected to as well as possible.

Cybathlon is intended to drive forward the development of prostheses and other types of assistive aids. Today, such technologies are often highly advanced technically, but provide limited value in everyday life.

An Oct. 4, 2016 Chalmers University of Technology press release by Johanna Wilde, which originated the news item, provides details about the competitor, his prosthetic device, and more,

Magnus, one of the participants, has now had his biomechatronically integrated arm prosthesis for almost four years. He says that his life has totally changed since the implantation, which was performed by Dr Rickard Brånemark, associate professor at Sahlgrenska University Hospital.

“I don’t feel handicapped since I got this arm”, says Magnus. “I can now work full time and can perform all the tasks in both my job and my family life. The prosthesis doesn’t feel like a machine, but more like my own arm.”

Magnus lives in northern Sweden and works as a lorry driver. He regularly visits Gothenburg in southern Sweden and carries out tests with researcher Max Ortiz Catalan, assistant professor at Chalmers University of Technology, who has been in charge of developing the technology and leads the team competing in the Cybathlon.

“This is a completely new research field in which we have managed to directly connect the artificial limb to the skeleton, nerves and muscles,” says Dr Max Ortiz Catalan. “In addition, we are including direct neural sensory feedback in the prosthetic arm so the patient can intuitively feel with it.”

Today Magnus can feel varying levels of pressure in his artificial hand, something which is necessary to instinctively grip an object firmly enough. He is unique in the world in having a permanent sensory connection between the prosthesis and his nervous system, working outside laboratory conditions. Work is now under way to add more types of sensations.

At the Cybathlon he will be competing for the Swedish team, which is formed by Chalmers University of Technology, Sahlgrenska University Hospital and the company Integrum AB.

The competition has a separate discipline for arm prostheses. In this discipline Magnus has to complete a course made up of six different stations at which the prosthesis will be put to the test. For example, he has to open a can with a can opener, load a tray with crockery and open a door with the tray in his hand. The events at the Cybathlon are designed to be spectator-friendly while being based on various operations that the participants have to cope with in their daily lives.

“However, the competition will not really show the unique advantages of our technology, such as the sense of touch and the bone-anchored attachment which makes the prosthesis comfortable enough to wear all day,” says Max Ortiz Catalan.

Magnus is the only participant with an amputation above the elbow. This naturally makes the competition more difficult for him than for the others, who have a natural elbow joint.

“From a competitive perspective Cybathlon is far from ideal to demonstrate clinically viable technology,” says Max Ortiz Catalan. “But it is a major and important event in the human-machine interface field in which we would like to showcase our technology. Unlike several of the other participants, Magnus will compete in the event using the same technology he uses in his everyday life.”

Facts about Cybathlon
•    The very first Cybathlon is being organised by the Swiss university ETH Zürich.
•    The €5 million event will take place in Zürich´s 7600 spectator ice hockey stadium, Swiss Arena.
•    74 participants are competing for 59 different teams from 25 countries around the world. In total, the teams consist of about 300 scientists, engineers, support staff and competitors.
•    The teams range from small ad hoc teams to the world’s largest manufacturers of advanced prostheses.
•    The majority of the teams are groups from research labs and many of the prostheses have come straight out of the lab.
•    Unlike the Olympics and Paralympics, the Cybathlon participants are not athletes but ordinary people with various disabilities. The aims of the competition are to establish a dialogue between academia and industry, to facilitate discussion between technology developers and people with disabilities and to promote the use of robotic assistive aids to the general public.
•    Cybathlon will return in 2020, as a seven-day event in Tokyo, to coincide with the Olympics.

Facts about the Swedish team
The Opra Osseointegration team is a multidisciplinary team comprising technical and medical partners. The team is led by Dr Max Ortiz Catalan, assistant professor at Chalmers University of Technology, who has been in charge of developing the technology in close collaboration with Dr Rickard Brånemark, who is a surgeon at Sahlgrenska University Hospital and an associate professor at Gothenburg University. Dr Brånemark led the team performing the implantation of the device. Integrum AB, a Swedish company, complements the team as the pioneering provider of bone-anchored limb prostheses.

This video gives you an idea of what it’s in store on Oct. 8, 2016,

Nanocellulose as scaffolding for nerve cells

Leave a reply

Swedish scientists have announced success with growing nerve cells using nanocellulose as the scaffolding. From the March 19, 2012 news item on Naowerk,

Researchers from Chalmers and the University of Gothenburg have shown that nanocellulose stimulates the formation of neural networks. This is the first step toward creating a three-dimensional model of the brain. Such a model could elevate brain research to totally new levels, with regard to Alzheimer’s disease and Parkinson’s disease, for example.

…

“This has been a great challenge,” says Paul Gatenholm, Professor of Biopolymer Technology at Chalmers.?Until recently the cells were dying after a while, since we weren’t able to get them to adhere to the scaffold. But after many experiments we discovered a method to get them to attach to the scaffold by making it more positively charged. Now we have a stable method for cultivating nerve cells on nanocellulose.”

When the nerve cells finally attached to the scaffold they began to develop and generate contacts with one another, so-called synapses. A neural network of hundreds of cells was produced. The researchers can now use electrical impulses and chemical signal substances to generate nerve impulses, that spread through the network in much the same way as they do in the brain. They can also study how nerve cells react with other molecules, such as pharmaceuticals.

I found the original March 19, 2012 press release  and an image on the University of Chalmers website,

Nerve cells growing on a three-dimensional nanocellulose scaffold. One of the applications the research group would like to study is destruction of synapses between nerve cells, which is one of the earliest signs of Alzheimer’s disease. Synapses are the connections between nerve cells. In the image, the functioning synapses are yellow and the red spots show where synapses have been destroyed. Illustration: Philip Krantz, Chalmers

This latest research from Gatenholm and his team will be presented at the American Chemical Society annual meeting in San Diego, March 25, 2012.

The research team from Chalmers University and its partners are working on other applications for nanocellulose including one for artificial ears. From the Chalmers University Jan. 22, 2012 press release,

As the first group in the world, researchers from Chalmers will build up body parts using nanocellulose and the body’s own cells. Funding will be from the European network for nanomedicine, EuroNanoMed.

Professor Paul Gatenholm at Chalmers is leading and co-ordinating this European research programme, which will construct an outer ear using nanocellulose and a mixture of the patient’s own cartilage cells and stem cells.

…

Previously, Paul Gatenholm and his colleagues succeeded, in close co-operation with Sahlgrenska University Hospital, in developing artificial blood vessels using nanocellulose, where small bacteria “spin” the cellulose.

In the new programme , the researchers will build up a three-dimensional nanocellulose network that is an exact copy of the patient’s healthy outer ear and construct an exact mirror image of the ear. It will have sufficient mechanical stability for it to be used as a bioreactor, which means that the patient’s own cartilage and stem cells can be cultivated directly inside the body or on the patient, in this case on the head. [Presumably the patient has one ear that is healthy and the researchers are attempting to repair or replace an unhealthy ear on the other side of the head.]

As for the Swedish perspective on nanocellulose (from the 2010 press release),

Cellulose-based material is of strategic significance to Sweden and materials science is one of Chalmers eight areas of advance. Biopolymers are highly interesting as they are renewable and could be of major significance in the development of future materials.

Further research into using the forest as a resource for new materials is continuing at Chalmers within the new research programme that is being built up with different research groups at Chalmers and Swerea – IVF. The programme is part of the Wallenberg Wood Science Center, which is being run jointly by the Royal Institute of Technology in Stockholm and Chalmers under the leadership of Professor Lars Berglund at the Royal Institute of Technology.

The 2012 press release announcing the work on nerve cells had this about nanocellulose,

Nanocellulose is a material that consists of nanosized cellulose fibers. Typical dimensions are widths of 5 to 20 nanometers and lengths of up to 2,000 nanometers. Nanocellulose can be produced by bacteria that spin a close-meshed structure of cellulose fibers. It can also be isolated from wood pulp through processing in a high-pressure homogenizer.

I last wrote about the Swedes and nanocellulose in a Feb. 15, 2012 posting about recovering it (nanocellulose) from wood-based sludge.

As for anyone interested in the Canadian scene, there is an article by David Manly in the Jan.-Feb. 2012 issue of Canadian Biomass Magazine that focuses largely on economic impacts and value-added products as they pertain to nanocellulose manufacturing production in Canada. You can also search this blog as I have covered the nanocellulose story in Canada and elsewhere as extensively as I can.