Scientists have built a light-weight wearable boot-like exoskeleton which reduces the energy needed for walking.
Researchers say the exoskeleton gives a 7% gain without chemical or electrical energy.
According to research published in the journal Nature, the energy saving is relatively modest but represents a considerable improvement on past designs.
Engineers have been trying to create machines since at least the 1890s to make walking easier but it is only recently that any attempt has met with success.
Steven Collins of the Department of Mechanical Engineering at Carnegie Mellon University and colleagues say the device acts in parallel with the user’s calf muscles, off-loading muscle force and reducing the energy consumed in contractions.
The device uses a mechanical clutch to hold a spring as it is stretched and relaxed by ankle movements when the foot is on the ground, helping to fulfil one function of the calf muscles and Achilles tendon.
People take about 10,000 steps a day or hundreds of millions of steps in a lifetime.
“While strong natural pressures have already shaped human locomotion, improvements in efficiency are still possible,” the study says. “Much remains to be learned about this seemingly simple behaviour.”
Watch the exoskeleton in action:
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.
It might seem like science fiction but a new implant which attaches directly to the spine could help paralysed people walk again
Paralysed patients have been given new hope of recovery after rats with severe spinal injuries walked again through a ‘groundbreaking’ new cyborg-style implant.
In technology which could have come straight out of a science fiction novel or Hollywood movie, French scientists have created a thin prosthetic ribbon, embedded with electrodes, which lies along the spinal cord and delivers electrical impulses and drugs.
The prosthetic, described by British experts as ‘quite remarkable’, is soft enough to bend with tissue surrounding the backbone to avoid discomfort.
Paralysed rats who were fitted with the implant were able to walk on their own again after just a few weeks of training.
Researchers at the Ecole Polytechnique Fédérale de Lausanne are hoping to move to clinical trials in humans soon. They believe that a device could last 10 years in humans before needing to be replaced.
The implant, called ‘e-Dura’, is so effective because it mimics the soft tissue around the spine – known as the dura mater – so that the body does not reject its presence.
“Our e-Dura implant can remain for a long period of time on the spinal cord or cortex,” said Professor Stéphanie Lacour.
“This opens up new therapeutic possibilities for patients suffering from neurological trauma or disorders, particularly individuals who have become paralyzed following spinal cord injury.”
Previous experiments had shown that chemicals and electrodes implanted in the spine could take on the role of the brain and stimulate nerves, causing the rats’ legs to move involuntarily when they were placed on a treadmill.
But this is the first study to show a simple gadget can help rats walk again and be tolerated by the body.
Scientists have struggled to find a device which will sit next to the spine or brain because both are surrounded by a protective envelope of tissue which the hard surface of implants can rub against, causing inflammation and scar tissue
However the new gadget is flexible and stretchy enough that it can be placed directly onto the spinal cord. It closely imitates the mechanical properties of living tissue, and can simultaneously deliver electric impulses and drugs which activate cells.
The implant is made of silicon and covered with gold electric conducting tracks that can be pulled and stretched. The electrodes are made of silicon and platinum microbeads which can also bend in any direction without breaking.
Writing in the journal Science, where the results were published, science writer Robert Service said: “Soft flexible nerves connected to unyielding silicon and metal – the combination has spawned many a Hollywood cyborg.
“The implants Lacour’s team created still have to be wired to the outside world to operate, but she and her colleagues are designing wireless versions of the technology. Watch out, Hollywood, reality is catching up.”
The research was praised by British scientists.
“The work described here is a groundbreaking achievement of technology, which could open a door to a new era in treatment of neuronal damage,” said Dr Duško Ilić, Reader in Stem Cell Science at King’s College London.
“Until now, the most advanced prostheses in intimate contact with the spinal cord caused quite substantial damage to tissue in just one week due to their stiffness.
“There is still a long way to go before we may see any practical use of such neuroprostheses in humans. But it may be that it is something that could potentially be developed for use in humans in the foreseeable future.”
Prof John Hunt, Head of Unit of Clinical Engineering, University of Liverpool, added: “This study in rats is an interesting one and it could have the potential to be quite promising in terms of being applicable to people with spinal injuries.”
The implant has been primarily tested in cases of spinal cord injury in paralyzed rats but researchers believe it could eventually be used in epilepsy, Parkinson’s disease and pain management.
The scientists are planning to move towards clinical trials in humans within the next few years.
The research was published in the journal Science.
Grad student Chi Lu and colleagues demonstrate a highly flexible polymer probe for triggering spinal-cord neurons with light and simultaneously recording their activity.
MIT researchers have demonstrated a highly flexible neural probe made entirely of polymers that can both optically stimulate and record neural activity in a mouse spinal cord — a step toward developing prosthetic devices that can restore functionality to damaged nerves.
“Our goal was to create a tool that would enable neuroscientists and physicians to investigate spinal-cord function on both cellular and systems levels with minimal impact on the tissue integrity,” notes Polina Anikeeva, the AMAX Assistant Professor in Materials Science and Engineering and a senior author of the paper published Nov. 7 in Advanced Functional Materials.
Department of Materials Science and Engineering graduate student Chi (Alice) Lu, who designed and implanted the probe, is the lead author of the study. Co-authors include Ulrich Froriep of the Simons Center for the Social Brain; Ryan Koppes of the Research Laboratory of Electronics; Andres Canales and Jennifer Selvidge of the Department of Materials Science and Engineering; and Vittorio Caggiano and Emilio Bizzi of the McGovern Institute for Brain Research. Professor Yoel Fink provided access to the fiber-drawing tower.
Although optogenetics, a method that makes mammalian nerve cells sensitive to light via genetic modification, has been applied extensively in investigation of brain function over the past decade, spinal-cord research has lagged. Earlier this year Caggiano and Bizzi have demonstrated inhibition of motor functions using optogenetics, and now the collaboration between the two groups yielded a device suitable for spinal optical excitation of muscle activity, while giving the researchers an electrical readout.
“Working in a spinal cord is significantly more difficult than in the brain because it experiences more movements. The radius of the mouse spinal cord is about 1 millimeter, and it is very soft, so it took some time to figure out how to design a device that would perform the stimulation and recording without damaging that tissue,” Lu explains.
The fiber was drawn from a template nearly 1.5 inches thick to its final diameter comparable to that of a human hair. It is flexible enough to be tied in a knot. The probe consists of a transparent polycarbonate optical core; parallel conductive polyethylene electrodes for recording neuronal electrical activity; and cyclic olefin copolymer acting both as electrical insulation and optical cladding. The flexible probe maintains its optical and electrical functions when bent by up to 270 degrees at very small radii of curvature (e.g. 500 µm), albeit with somewhat diminished light-carrying capacity at those conditions. The device still performed well after repeated bending and straightening, holding up under stresses expected from normal body movements, the report shows. MIT has filed a patent on the device platform.
The researchers conducted experiments with their neural probe in genetically-altered mice that express the light-sensitive protein channelrhodopsin 2 (ChR2) labeled with yellow fluorescent protein. The ChR2 makes neurons in the mice respond to blue light. These mice, developed by Professor Guoping Feng and colleagues at the McGovern Institute for Brain Research, provide a convenient model system for optoelectronic neural prosthetics. “When pulses of blue light are delivered to the spinal cord, we can directly observe neuronal response by getting an electrical recording,” explains Lu, who entered the third year of her doctoral program this fall.
“Laser pulses … delivered through the [polycarbonate] core of the fiber probe robustly evoked neural activity in the spinal cord, as recorded with the … electrodes integrated within the same device,” the researchers report.
The fiber was inserted into the proximal lumbar section of the spinal cord in mice, and light delivered through it triggered activity in one of the calf muscles, the gastrocnemius muscle. The results in the optically-sensitive mice were validated by comparison with results in wild type mice, which showed no response to the optical trigger. A toe pinch showed the device could still record mechanically stimulated neuronal activity in the wild-type mice. The researchers monitored muscle activity through electromyographical (EMG) recording, while the conductive polyethylene electrodes in the new device recorded neuronal activity in the spinal cord.
The MIT researchers’ combination in a single system of both recording activity from neurons and stimulating neurons with light is new, says Ravi V. Bellamkonda, the Wallace H. Coulter Professor and Department Chair of Biomedical Engineering at Georgia Institute of Technology and the Emory School of Medicine. “In principle, one would like to use ‘closed-loop’ systems, i.e., you detect a neurological event — like the brain wanting to move a limb — and then stimulate to affect that function when the natural link between them is severed due to an injury like spinal cord damage,” he explains.
“This is excellent engineering combining electrical and optical engineering for an important biological application — modulation of neural function in a closed-loop way. I am eager to see this technology being used in a biologically significant ways in the future,” Bellamkonda says.
The work was funded in part by grants from the National Science Foundation through the Center for Sensorimotor Neural Engineering and Center for Materials Science and Engineering; the McGovern Institute for Brain Research Neurotechnology Program; and the Simons Foundation.
Source: MIT press release
Image Source: The image is credited to the Chi (Alice) Lu and Polina Anikeeva and is adapted from the MIT press release
Original Research: Abstract for “Polymer Fiber Probes Enable Optical Control of Spinal Cord and Muscle Function In Vivo” by Chi Lu, Ulrich P. Froriep, Ryan A. Koppes, Andres Canales, Vittorio Caggiano, Jennifer Selvidge, Emilio Bizzi and Polina Anikeeva in Advanced Functional Materials. Published online August 26 2014 doi:10.1002/adfm.201401266
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…
A group of researchers from Penn State have pushed the realm of possibilities for nanotechnology further as they have successfully steered a nanomotor inside of a human cell. This is the first time this feat has been accomplished. The team of chemists, biologist, and engineers was led by Tom Mallouk and has been published in Angewandte Chemie International Edition.
Nanomotors have been studied in vitro more more than a decade now. The hope is that eventually, they could be used inside of human cells for biomedical research. This nanotechnology could revolutionize drug delivery and even perform surgery in order to increase quality of life in the least invasive way possible. The earliest models were nonfunctional in biological fluid due to their fuel source. A huge breakthrough came later when the nanomotors were able to be powered externally via acoustic waves. The nanomotors used inside the human cells for the latest study were controlled by the ultrasonic waves as well as magnets.
The researchers used HeLa cells, derived from a long-lived line of cervical cancer cells, to study the nanomotors. Getting past the cell membrane was easy, as the cells ingested the nanomotors themselves. Once inside, the ultrasound was turned on and the nanomotors began to spin and move around the cell. If the signal was turned up even higher, the nanomotor can spin like a propeller, chopping up the organelles inside the cell. They were even able to puncture the cell membrane, finishing off the death sentence. Used at low powers, the nanomotor was able to move around the cell without causing any damage.
The addition of magnets gave an important advantage: steering. The motors are also able to be controlled individually, allowing the operator to take a much more targeted approach to killing diseased cells.
Ultimately, the researchers hope that one day the rocket-shaped gold nanorods will be able to move in an out of the cells without causing damage. The individual units could communicate with one another to target disease in the body, maximizing the efficacy of the treatment or even making the correct diagnosis. Working toward the goal of creating such advanced nanotechnology will not only push the boundaries of nanoengineering, but will increase our understanding of chemical and biological processes at the cellular level as well.
“The assembly of a rotating HeLa cell/gold rod aggregate at an acoustic nodal line in the xy plane. The video was taken under 500X overall magnification except for 00:23 – 00:32 and 01:16 – 01:42, where a 200X overall magnification was used.” Credit: Mallouk Lab, Penn State
“Very active gold nanorods internalized inside HeLa cells in an acoustic field. A demonstration of very active gold nanorods internalized inside HeLa cells in an acoustic field. This video was taken under 1000X magnification in the bright field, with most of the incoming light blocked at the aperture.” Credit: Mallouk Lab, Penn State
The adage “Take two aspirin and call me in the morning” is destined for a futuristic makeover. Doctors may just as easily recommend swallowing sophisticated gadgets instead.
That is the hope of prolific inventor Mir Imran, who has created a robotic pill to replace injectable drugs for chronic conditions such as diabetes. The gadget, in preclinical studies and backed by Google Inc.’s venture-capital unit, consists of an ingestible polymer and tiny hollow needles made of sugar that are designed to safely deliver drugs to the small intestine.
Such a pill would have seemed unthinkable years ago. But advancements in technology and scientific research have recently led to two federally approved robotic pills.
The Food and Drug Administration earlier this month cleared the PillCam, a pill-sized camera from Given Imaging Ltd. that photographs human insides in a hunt for colon polyps. Another company, Proteus Digital Health Inc., received clearance a year and a half ago to put ingestible sensors inside pills to help patients and doctors determine how many they have taken.
Mr. Imran’s pill hasn’t yet been tested in humans, so it is probably still at least a year away from even seeking federal approval. It also would require substantial financing to manufacture millions of pills. But if it is successful, the gadget has the potential to disrupt a multibillion-dollar market for injectable drugs and make life easier for millions of sufferers of conditions such as diabetes and rheumatoid arthritis.
Mr. Imran is a safer bet than most entrepreneurs. The Indian-born founder of the research lab and business incubator InCube Labs in Silicon Valley has founded more than 20 medical-device startups, a dozen of which have been acquired by companies such as Medtronic Inc. He owns over 300 patents and helped develop the first implantable cardioverter defibrillator to correct irregular heartbeats.
Rani Therapeutics, the startup formed at InCube Labs to commercialize the robot pill, last year raised funds from Google Ventures and angel-investment fund VentureHealth.
Blake Byers, the Google Ventures general partner who spearheaded the investment, says Mr. Imran may be achieving one of the “holy grails” for biotechnology by figuring out how to deliver protein-based drugs such as basal insulin to the body without the use of a syringe.
“This investment is not exactly in our wheelhouse, but we’re open to people who can change our minds,” Mr. Byers said. “This one really stood out as a huge clinical need; $110 billion is spent in the U.S. every year on biologics, all of them injectable.”
Drugs used to treat a variety of chronic conditions, including diabetes, rheumatoid arthritis, osteoporosis and multiple sclerosis, can’t be delivered in pill form because stomach acids break down the proteins.
Mr. Imran’s idea is an “autonomic robotic delivery system” that can stay intact in the stomach and small intestine long enough to deliver enough of the drug. The body’s natural digestive processes activate the pill to perform a series of functions even without any electronics.
As the pH level, or acidity, builds up in the intestine, the outer layer of the polymer pill casing dissolves, exposing a tiny valve inside the device that separates two chemicals, citric acid and sodium bicarbonate.
When the valve becomes exposed, the chemicals mix together to create carbon dioxide. This acts as an energy source, gently inflating a balloon-like structure that is outfitted with needles made of sugar and preloaded with drugs.
The needles push into the intestinal wall, which has no pain receptors. Once lodged there, they detach from the gadget and slowly dissolve, while the balloon and polymer casing pass from the body.
In numerous attempts over the past 40 years to make insulin and other drugs available in pill form, pharmaceutical companies have been able to create coatings so tough that pills can reach the small intestine. But once there, they are attacked by enzymes, which has compromised the pills and prevented significant amounts of the drug from reaching the patient.
In preclinical studies, Rani Therapeutics has shown that its robotic pill can boost drug absorption at least as high as syringes can, Mr. Imran said.
“I am guardedly optimistic, and I say guardedly because there is still a lot of work left to do,” said Elliott Sigal, who several months ago retired from drug maker Bristol-Myers Squibb Co. His 16-year run at the drug maker included top posts in drug discovery and development and a nearly 10-year tenure as the head of research and development.
“Rani’s engineering-based approach to this is very innovative,” said Mr. Sigal, who doesn’t have a financial stake in the business. “He is getting results that I have not seen before. It hasn’t been tried in human patients yet, and things do sometimes fail at that level. But if the [trials] data continues, there will be a great deal of pharma interest.”
Mr. Imran said pharmaceutical companies, which would license the technology for use with their own drugs, have already expressed interest. He declined to give further details.
Rani Therapeutics will spend another year testing the robot pill, he said, in the hope that it will have definitive clinical data in 2015.
If the data back up his claim about the pill, it could not only help millions of patients ditch their syringes and stick-pens, but it could remove another barrier for a range of early-stage treatments that currently have no safe avenue into the body, said Google Ventures’ Mr. Byers.
Here is also a short video: Can ‘Robotic’ Pills Replace Injections?