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:
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
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?
A 14-month-old boy in need of life-saving heart surgery is the beneficiary of a collaboration among University of Louisville engineers, physicians and Kosair Children’s Hospital.
Roland Lian Cung Bawi of Owensboro was born with four congenital heart defects and his doctors were looking for greater insights into his condition prior to a Feb. 10 operation.
Philip Dydynski, chief of radiology at Kosair Children’s Hospital, recently had toured the Rapid Prototyping Center at the University of Louisville’s J.B. Speed School of Engineering and became impressed with the 3D printing capabilities available there.
He asked the center’s operations manager, Tim Gornet, if a 3D model of the child’s heart could be constructed using a template created by images from a CT scan to allow doctors to better plan and prepare for his surgery. No problem, Gornet said.
The result of the Rapid Prototyping Center’s work was a model heart 1.5 times the size of the child’s. It was built in three pieces using a flexible filament and required about 20 machine hours – and only about $600 — to make, Gornet said.
Once the model was built, Erle Austin III, cardiothoracic surgeon with University of Louisville Physicians, was able to develop a surgical plan and complete the heart repair with only one operation.
“I found the model to be a game changer in planning to do surgery on a complex congenital heart defect,” he said.
Roland was released from Kosair Children’s Hospital Feb. 14 and returned Feb. 21 for checkups with his doctors. His prognosis is good.
That’s good news for Gornet, whose work at the Rapid Prototyping Center routinely benefits manufacturers and heavy industry. Helping surgeons save a life was new territory for him.
“Knowing we can make somebody’s life better is exciting,” he said.
Swedish researchers at Uppsala University have, together with Brazilian collaborators, discovered a new group of nerve cells that regulate processes of learning and memory. These cells act as gatekeepers and carry a receptor for nicotine, which can help explain our ability to remember and sort information.
The discovery of the gatekeeper cells, which are part of a memory network together with several other nerve cells in the hippocampus, reveal new fundamental knowledge about learning and memory. The study is published today in Nature Neuroscience.
The hippocampus is an area of the brain that is important for consolidation of information into memories and helps us to learn new things. The newly discovered gatekeeper nerve cells, also called OLM-alpha2 cells, provide an explanation to how the flow of information is controlled in the hippocampus. Read more…
Simply activating a tiny number of neurons can conjure an entire memory.
Our fond or fearful memories — that first kiss or a bump in the night — leave memory traces that we may conjure up in the remembrance of things past, complete with time, place and all the sensations of the experience. Neuroscientists call these traces memory engrams.
But are engrams conceptual, or are they a physical network of neurons in the brain? In a new MIT study, researchers used optogenetics to show that memories really do reside in very specific brain cells, and that simply activating a tiny fraction of brain cells can recall an entire memory — explaining, for example, how Marcel Proust could recapitulate his childhood from the aroma of a once-beloved madeleine cookie.
“We demonstrate that behavior based on high-level cognition, such as the expression of a specific memory, can be generated in a mammal by highly specific physical activation of a specific small subpopulation of brain cells, in this case by light,” says Susumu Tonegawa, the Picower Professor of Biology and Neuroscience at MIT and lead author of the study reported online today in the journal Nature. “This is the rigorously designed 21st-century test of Canadian neurosurgeon Wilder Penfield’s early-1900s accidental observation suggesting that mind is based on matter.” Read more…