Thursday, August 14, 2008
The Robot And Its Biological Brain
Scientists from the University of Reading have cultured cells from rat brains and used the matrix to control a robot's movement, keeping it from hitting the wall.
The robot's biological brain is made up of cultured neurons which are placed onto a multi electrode array (MEA). The MEA is a dish with approximately 60 electrodes which pick up the electrical signals generated by the cells. This is then used to drive the movement of the robot. Every time the robot nears an object, signals are directed to stimulate the brain by means of the electrodes. In response, the brain's output is used to drive the wheels of the robot, left and right, so that it moves around in an attempt to avoid hitting objects. The robot has no additional control from a human or a computer, its sole means of control is from its own brain.The researchers are now working towards getting the robot to learn by applying different signals as it moves into predefined positions. It is hoped that as the learning progresses, it will be possible to witness how memories manifest themselves in the brain when the robot revisits familiar territory.
Professor Kevin Warwick from the School of Systems Engineering, said: "This new research is tremendously exciting as firstly the biological brain controls its own moving robot body, and secondly it will enable us to investigate how the brain learns and memorises its experiences. This research will move our understanding forward of how brains work, and could have a profound effect on many areas of science and medicine."
Video from the New Scientist:
University of Reading press release: Robot with a Biological Brain: new research provides insights into how the brain works...
More at the New Scientist...
(hat tip: Drudge Report)
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Friday, June 20, 2008
A More Natural Prosthetic Foot
While still in its prototype phase, the Tensegrity foot is designed to mimic the action of a jointed foot to allow for a more natural and stable gait. Built by inventor and mechanical engineer Jerome Rifkin, the artificial foot bends like a normal foot and ankle, and conforms to the terrain underneath it. The prosthetic options for foot amputees is limited due to the complexity involved in mimicking the weight-bearing action and propulsion involved with the foot. Mechanical prosthetics often do not mimic the motion of a natural foot, and other prosthetics cost a significant amount and are not covered by insurance.
The Tensegrity foot is different. POPSCI explains:
Rifkin built something that combined the natural step of a bionic foot with the simplicity and low cost of a mechanical prosthetic. His jointed foot has a heel, a forefoot, a big toe—and no joint at the ankle. Instead, a novel midfoot joint, which connects the heel and forefoot, does the job of both the ankle and the arch. Like an ankle joint, it flexes up and down to give the wearer a more natural step. And, like a real midfoot joint, it creates a flexible arch in the middle of the foot. A spring and cable connect it to a second joint at the toe, to create extra push-off at the end of each step. Other tensioned steel cables serve as the tendons and ligaments that govern its range of motion—the user doesn’t control it, it simply responds to the pressure of walking. Because the front and back of the foot can move independently, it can react to uneven terrain.With input from 11 amputee test users like Link, Rifkin is refining his fifth (and, he hopes, final) prototype, made primarily of magnesium for its strength and low weight. Early results indicate that the one-pound foot reduces the amount of energy required for each step because it uses the force absorbed by the spring and joints to help propel the foot forward. “It’s the equivalent of taking a 50-pound pack off your back,” he explains. That’s on par with the best bionic feet, without all the expensive motors and artificial intelligence."
Image: How the K3 Promoter Works: A flexible midfoot joint makes the prosthetic stable on uneven ground, and a spring-loaded toe provides push-off for each step.
More from POPSCI.COM
Company page:: Tensegrity Prosthetics
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Tuesday, April 29, 2008
Fluidhand: Prototype Prosthetic Device
Fluidhand (pictured above), a new prosthetic device currently developed as a prototype, is being tested at the Orthopedic University Hospital in Heidelberg. In addition to being softer and more natural than other conventional hand prosthetic devices, it allows the user to fully wrap around and grip objects while providing feedback to give the amputee a sense of the strength of the grip. An 18 year old patient at the hospital was the first person in the world to test and compare the 
Fluidhand to the i-LIMB (previously covered by Medgadget here, and pictured to the right) and a second patient is soon to be fitted with the new prosthesis.
Unlike its predecessors, the new hand can close around objects, even those with irregular surfaces. A large contact surface and soft, passive form elements greatly reduce the gripping power required to hold onto such an object. The hand also feels softer, more elastic, and more natural than conventional hard prosthetic devices.The flexible drives are located directly in the movable finger joints and operate on the biological principle of the spider leg - to flex the joints, elastic chambers are pumped up by miniature hydraulics. In this way, index finger, middle finger and thumb can be moved independently. The prosthetic hand gives the stump feedback, enabling the amputee to sense the strength of the grip
Press Release: A new prosthetic hand is being tested at the Orthopedic University Hospital in Heidelberg / Grip function almost like a natural hand
We'd like to welcome Rohit Joshi, a medical student at McMaster University in Canada, as an associate editor of Medgadget, this being his first post in the role.
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Friday, March 14, 2008
Femtosecond Lazers: Killing Cancer & Fusing Metal to Bone
University of Missouri scientists are working to bring functional femtosecond lasers [as in beams] out of the real of sci-fi and into the real world of medicine. Lead researcher, and professor of Mechanical and Aerospace Engineering, Robert Tzou explains how this new technology could revolutionize everything from dentistry to oncology to joint replacement surgery.
What makes the femtosecond laser different from other lasers is its unique capacity to interact with its target without transferring heat to the area surrounding its mark. The intensity of the power gets the job done while the speed ensures heat does not spread. Results are clean cuts, strong welds and precision destruction of very small targets, such as cancer cells, with no injury to surrounding materials. Tzou hopes that the laser would essentially eliminate the need for harmful chemical therapy used in cancer treatments.“If we have a way to use the lasers to kill cancer cells without even touching the surrounding healthy cells, that is a tremendous benefit to the patient,” Tzou said. “Basically, the patient leaves the clinic immediately after treatment with no side effects or damage. The high precision and high efficiency of the UUL allows for immediate results.”
Practical applications of this type of laser also include, but aren’t limited to, the ability to create super-clean channels in a silicon chip. [Ed note: we can think of more applications later...] That process can allow doctors to analyze blood one cell at a time as cells flow through the channel. The laser can be used in surgery to make more precise incisions that heal faster and cause less collateral tissue damage. In dentistry, the laser can treat tooth decay without harming the rest of the tooth structure.
Associate Professor Yuwen Zhang and Professor Jinn-Kuen Chen recently received a grant from the National Science Foundation to use the laser to “sinter” metal powders—turn them into a solid, yet porous, mass using heat but without massive liquefaction—a process which can help improve the bond between joint implants and bone.
“With the laser, we can melt a very thin strip around titanium micro- and nanoparticles and ultimately control the porosity of the bridge connecting the bone and the alloy,” Zhang said. “The procedure allows the particles to bond strongly, conforming to the two different surfaces.”
(hat tip: Gizmodo)
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Monday, February 4, 2008
DARPA Backs Luke Arm (Updated below)
This morning we wrote that DARPA is about to decide whether to continue development of the world's most advanced prosthesis, now called the Luke Arm. A press release from the Johns Hopkins Applied Physics Laboratory announcing $31 million of funding from DARPA, and Hopkins' leading role in the next stage of development, sounds like a bright green light for the project.
The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., has received a contract from the Defense Advanced Research Projects Agency to complete development of a prosthetic arm that will be controlled, feel, look and perform like a natural limb. Funding will support Phase 2 of DARPA’s Revolutionizing Prosthetics 2009 (RP 2009) program, an ambitious effort to provide the most advanced medical and rehabilitative technologies for military personnel injured in the line of duty.In Phase 1, the APL-led RP 2009 team of approximately 30 organizations developed two prototypes. The first prototype, presented to DARPA less than a year after the project started, is a fully integrated prosthetic arm that can be controlled naturally, provide sensory feedback and allows for eight degrees of freedom – a level of control far beyond the current state of the art for prosthetic limbs. The Proto 1 limb system also includes a virtual environment used for patient training, clinical configuration, and to record limb movements and control signals during clinical investigations.
The second prototype, demonstrated at DARPA Tech 2007 last August, has 25 individual joints that approach the natural speed and range of motion of the human limb. These mechanical limb systems are complemented by a range of emerging neural integration strategies that promise to restore near-natural control and important sensory feedback capabilities.
Press releases: DARPA Gives APL-Led Revolutionizing Prosthetics 2009 Team Green Light for Phase 2; APL to Lead Team Developing Revolutionary Prosthesis
UPDATE: It appears that we've got mixed up by all the ongoing bionic arms projects. Medgadget reader TroyTurner left the following important comment:
I would like to clarify some of the information in your article above as it appears that two great research efforts are being confused &/or intermingled. While your headline, accompanying photo, and first sentence are about the Deka "Luke Arm", the rest of the story is about the Johns Hopkins University Applied Physics Lab (JHU-APL) device. Of course this also means that your headline isn't totally accurate. DARPA has awarded a phase II contract to JHU-APL, not Deka (though that is still being pursued.)In 2004/5, The Defense Advanced Research Projects Agency (DARPA) funded two distinctly separate prosthetic arm development projects.
One was called "Revolutionizing Prosthetics 2007", and was awarded to DEKA R&D (www.dekaresearch.com). The Deka effort, now being referred to as "The Luke Arm" (pictured in your post above), has been completed. The goal of this project was to build the very best prosthetic upper limb that could be built using currently available technology. It is possible that DARPA will fund a phase II for further work, though that has not yet happened.
The other award, "Revolutionizing Prosthetics 2009", went to the Johns Hopkins University Applied Physics Lab (JHU-APL). Managed by Stuart Harshbarger at JHU-APL, this international effort to develop an advanced neural controlled upper limb is well described in the news release from JHU-APL that you've included in your post above.
An important distinction between the two programs is that the APL effort includes the development of true neural control of the device, while the Deka "Luke Arm" is currently controlled using myoelectric controls, though Deka is working with other organizations to enable additional control methodologies.
Because of the goals & program names, this can be confusing even for folks who are close to the work. Great things coming out of these efforts: of course some amazing advances in prosthetics, but I also believe we're also going to see advances in many other area of biomed, robotics, etc. in years to come with roots embedded in these efforts.
Agreed. The search of our archives brings the following post from April 2007 about the JHU-APL integrated prosthetic arm project: Bionic Arm 2.0, Watch Out Dean Kaman. We appologize for the confusion.
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Update: Dean Kamen's Luke Arm
Dean Kamen's project to design and build the most advanced arm prosthesis, now called the Luke Arm, has wrapped up its mandate, and DARPA, the sponsor of the project, will be deciding whether to continue funding the arm and apply for clinical trials.
In order to make a better arm, Kamen first had to figure out what was wrong with the old one. Part of the reason the technology was still in “the Flintstones” was a lack of agility: a human arm has 22 degrees of freedom, not three. The Luke Arm prosthetic is agile because of the fine motor control imparted by the enormous amount of circuitry inside the arm, which enables 18 degrees of freedom. The engineers fought for space inside the arm and created workarounds when they couldn’t have the space they needed, such as using rigid-to-flex circuit boards folded into origami-like shapes inside the tiny spaces, which are connected by a dense thicket of wiring.The arm has motor control fine enough for test subjects to pluck chocolate-covered coffee beans one by one, pick up a power drill, unlock a door, and shake a hand. Six preconfigured grip settings make this possible, with names like chuck grip, key grip, and power grip. The different grips are shortcuts for the main operations humans perform daily.
The Luke arm also had to be modular, usable by anyone with any level of amputation. The arm works as though it had a very complicated set of vacuum cleaner attachments; the hand contains separate electronics, as does the forearm. The elbow is powered, and the electronics that power it are contained in the upper arm. The shoulder is also powered and can accomplish the never-before-seen feat of reaching up as if to pick an apple off a tree.
It must be less than what a native limb would have weighed, because in an amputee the human skeletal system can no longer be used as a method of attachment. Instead, for amputations above the elbow, a user is strapped into a kind of harness. Deka engineers modeled the arm based on the weight of a statistically average female arm (about 3.6 kg), including all the electronics and the lithium battery. Amazingly, titanium, the legendarily light material, is too heavy to keep the arm under its weight limit—it can’t be made thin enough without bending—so the arm is mostly aluminum.
More at IEEE Spectrum Online...
Flashbacks: Dean Kamen's DARPA Arm in the Lab, Dean Kamen and His Arm, Dean Kamen's Robotic Arm Part Deuce, Cyborg Arm: DARPA Recruits Dean Kaman, Dean Kamen Talks Medgadgets
(hat tip: Engadget)
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Monday, January 28, 2008
Bluetooth: The Next Advancement for Prosthetics
Marine Lance Cpl. Joshua Bleill has some of the hottest legs in town when he wears his cutting edge, bluetooth enabled bionic prosthetics.
Now, he's starting to walk again with the help of prosthetic legs outfitted with Bluetooth technology more commonly associated with hands-free cell phones."They're the latest and greatest," Bleill said, referring to his groundbreaking artificial legs.
Bleill, 30, is one of two Iraq war veterans, both double leg amputees, to use the Bluetooth prosthetics. Computer chips in each leg send signals to motors in the artificial joints so the knees and ankles move in a coordinated fashion.
Bleill's set of prosthetics have Bluetooth receivers strapped to the ankle area. The Bluetooth device on each leg tells the other leg what it's doing, how it's moving, whether walking, standing or climbing steps, for example.
"They mimic each other, so for stride length, for amount of force coming up, going uphill, downhill and such, they can vary speed and then to stop them again," Bleill told CNN from Walter Reed Army Medical Center, where he's undergoing rehab.
"I will put resistance with my own thigh muscles to slow them down, so I can stop walking, which is always nice."
CNN Video...
(hat tip: /.)
Flashbacks: The Power Knee, Adaptive Prosthetics, Rheo-Knee: Walk Your Way, Proprio Foot™...
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Thursday, January 10, 2008
Dr. Sethi and the Jaipur Foot
The New York Times has a nice obituary on Dr. Jaipur who changed the lives of countless amputees with his advanced, affordable prosthetics.
From the Times...
The Jaipur foot, which has never been patented, is available in more than 25 countries, most of them poor, many of them with great numbers of land-mine victims. Unlike many high-priced prostheses in developed countries, it can be made by traditional craftsmen, lasts more than five years and costs about $30, making it affordable for mass distribution...Dr. Sethi came up with his invention after years of extensive research. He was helped by Ramachandra Sharma, a semiliterate craftsman who had been teaching lepers to make handicrafts and who became his assistant.
The two made a foot of vulcanized rubber but found it too heavy and stiff. So they filled the shell with sponge rubber and modified the design. They used a stiff piece for the metatarsals and added microcellular rubber for the heel, cutting wedges at its upper end to make a universal joint.
Since 1971, when Dr. Sethi presented the foot to British orthopedic surgeons at Oxford, the Jaipur foot has revolutionized lives in war-torn countries. It is very flexible, allowing the wearer to run, climb trees or pedal bicycles. It is well suited to the needs of many Asian countries in which most people sit, eat, sleep and pray on the floor. Using the Jaipur foot, a Bollywood actor and dancer, Sudha Chandra, was even able to perform a demanding dance sequence in the movie musical "Nache Mayuri."
Technology notes from JaipurFoot.org:
1) The limbs made with this technology are closest to a normal human limb. The Jaipur Foot has virtually got the same range of movements which a normal human foot has. It has dorsi-flexion, inversion, eversion, supination, pronation and axial rotation allowing a amputee not only to walk comfortably, but also squat (sitting on hunches), kneeling, crouching, sitting cross legged, walking also on undulated terrain, running, climbing a tree and driving an automobile. In other words, it is an all-functional, all-terrain limb. The other limbs with SACH foot cannot have these flexions and functions. There are some Multi Axial Feet but these allow specific limited flexions and functions.
2) Jaipur Foot is cosmetically also closest to the human foot with toes etc. Once Jaipur Foot was developed many other companies in the world added these cosmetic feature to their limb products to look like normal Foot or Jaipur Foot.
3) Jaipur Foot is water proof as many other artificial limbs in the world are.
4) Jaipur Foot is a dual purpose foot. It may be worn with shoes or without shoes depending on the desire and the need of the patients. This feature is crucial for meeting the cultural needs of many regions of the world. For example most of the modern limbs can be used only with the shoes on with the result that such amputees cannot enter the temples, mosques etc and cannot pray or perform NAMAZ.
5) The normal life of Jaipur Foot piece is around 3 years.
Read on at NYT...
Design...
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Tuesday, January 8, 2008
Synth Skin for Your [Super Human] Prosthetic Arm
What good is a super human prosthetic arm in an arm wrestling competition, if the metallic parts give it away? That's why DARPA continues to fund projects aimed at the development of a highly realistic prosthetic "skin."
The new artificial skin will incorporate many more sensors and will cover the metallic prosthesis, leading to a more natural-looking bionic arm. The skin-a rubbery polymer called polyimide that has been infused with tiny carbon nanotubes-is flexible, stretchable, lightweight, and tough. Initially designed for airplane pressure sensors, the polymer is durable, resistant to high temperatures, and piezoelectric. That is, it generates electricity in response to pressure or force, so you can measure pressure applied to its surface, says NIA's [National Institute of Aerospace's] Cheol Park, who is leading the pressure-sensor development. Carbon nanotubes enhance the piezoelectricity of the polyimide and make the polymer stronger, he says.Temperature sensors will be embedded under the polyimide layer. The trick is to transfer heat as quickly as possible from the polymer surface to the sensors. Again, carbon nanotubes, which conduct heat along their length unusually well, will play a key role. Researchers at ORNL are trying to make nanotube-embedded polymers that conduct heat as well as human tissue does, says Ilia Ivanov, a nanomaterials researcher at ORNL. They will impregnate the polymer with an array of vertically aligned nanotubes, which will transfer heat from the skin surface to the temperature sensors underneath. Ivanov says the heat transfer should be fast. In 2006, researchers showed that a heat pulse travels 20 times as fast in a polymer containing the nanotube arrays than in the pure polymer.
More in Wired...
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Monday, January 7, 2008
I-Limb Bionic Hand Gets Upgradable Bionic Arm
Director of rehabilitation engineering services at NHS Lothian in Britain, David Gow, believes his new i-Limb system (bionic arm, hand combo) from Touch Bionics is so superior to biological limbs that it may have to "scale down its power." We've been waiting our whole lives to hear those sweet words.
"The i-Limb system is better than a human arm. It is faster and can lift heavier weights than a human arm. It also looks good, has smooth movement, and operates with less noise than existing prosthetic arms. The technology is new and evolving."However, we might have to scale the power down to make it suitable for everyone. With something that has a better than human performance, our challenge is ethical.
"A patient would have the potential to hurt themselves or other people with it as it is actually better than a human arm. It could do damage.
"We have got to take safety very seriously. You have to attach it to the patient's body and that could cause damage if the weight is too heavy. It could snap their ribs. And it could be pretty scary flapping about."
Read more at the Scotsman...
Flashbacks: Video of i-LIMB Hand; World's First Bionic Hand Makes It to Market
(hat tip: Engadget)
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Wednesday, August 29, 2007
Hearing from Inside: The Latest on Otologics Prosthesis
To update our readers, The MIT Technology Review has an article on a fully implantable hearing prosthesis from Otologics that we wrote about a year ago.
The device is powered by a battery that is recharged when the user places a small radio transmitter against his or her head for 60 to 90 minutes. The transmitter is held to the skin by a magnet in the implant. An inductive coil in the implant converts the radio energy to electricity and recharges the battery with it. The battery can stay inside the body for at least five years, according to the company, before it needs to be replaced. The implanted components are hermetically sealed together to protect against leaks, so the electronics, microphone, and inductive coil are replaced as well. However, the piston in the middle ear remains in place.The results of a phase I clinical trial of the hearing aid were reported in the August 2007 issue of Otolaryngology--Head and Neck Surgery. Twenty subjects with moderate to severe hearing loss were implanted in one ear. (Seventeen of the subjects had worn conventional hearing aids prior to the study.) The subjects did somewhat worse than with the hearing aid they had previously worn: their ability to hear a range of single-frequency tones dropped between 5 and 12 decibels, and mean word-recognition scores dropped from the low 80 percent range to the high 60 percent range.
On the other hand, a satisfaction survey found that the subjects felt that the device not only improved their hearing, but also sounded more natural than their old hearing aid. The authors of the study speculated that new processing algorithms would improve the test results. Otologics has indicated that it is already working on this.
More from MIT Tech Review...
Flashback: Otologics' Fully Implantable Hearing Device
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Tuesday, August 28, 2007
Dean Kamen and His Arm
Below is a five minute video of Dean Kamen describing how he came into the business of developing an almost fully articulated prosthetic arm. There is no new information about the arm in this particular presentation, since we've seen the capabilities before.
Link...
Flashbacks: Dean Kamen's Robotic Arm Part Deuce; Cyborg Arm: DARPA Recruits Dean Kaman; Dean Kamen Talks Medgadgets
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Friday, August 24, 2007
Airic's_arm from Festos
Festos, a manufacturer of industrial control systems, is using its own in-house technology to develop a pneumatic powered arm.
The Airic's_arm is a robotic arm fitted with artificial bones and muscles. The bone structure, consisting of the human bones such as ulna and radius, metacarpal bone and finger bone, shoulder joint and shoulder blade - joints that do not occur as such in the technical world - is moved via 30 muscles.
The muscles are Festo products, which are already put to extensive use in industrial practice and known as Fluidic Muscle. Using this technology, in conjunction with Festo's tiny, highly innovative piezo-proportional valves, it is possible to precisely regulate the forces and rigidity within the construction. These actuators can be coordinated using state-of-the-art mechatronic systems and software.
The possibility of enhancing the Airic's_arm sensors in the future, for instance by adding cameras or tactile perception elements, is just as feasible as the possibility of a further development in the form of back, hip and neck. Enhancements of this type will also be useful in robotics, as they could be used to assign even more hazardous tasks to technology.
Product page...
Flashbacks: The Vanderbilt Arm: Mini Rocket Engine Powered Prosthesis, Dean Kamen's Robotic Arm Part Deuce
(Hat tip: Engadget)
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Monday, August 20, 2007
The Vanderbilt Arm: Mini Rocket Engine Powered Prosthesis
Vanderbilt University scientists are developing an arm prosthesis that is powered by a miniaturized rocket engine. The advantage is stronger action of the artificial muscles, faster movement, and no need for batteries - now we're cooking with gas!
It was the poor power-to-weight ratio of batteries that drove Goldfarb [Michael Goldfarb, Professor of Mechanical Engineering at Vanderbilt] to look for alternatives in 2000 while he was working on a previous exoskeleton project for DARPA. He decided to miniaturize the monopropellant rocket motor system that is used for maneuvering in orbit by the space shuttle. His adaptation impressed the Johns Hopkins researchers, so they offered him $2.7 million in research funding to apply this approach to the development of a prosthetic arm.Goldfarb's power source is about the size of a pencil and contains a special catalyst that causes hydrogen peroxide to burn. When this compound burns, it produces pure steam. The steam is used to open and close a series of valves. The valves are connected to the spring-loaded joints of the prosthesis by belts made of a special monofilament used in appliance handles and aircraft parts. A small sealed canister of hydrogen peroxide that easily fits in the upper arm can provide enough energy to power the device for 18 hours of normal activity.
The first prototype, which took a year to develop, was powered by "cold gas": compressed nitrogen. It allowed the researchers to test the fundamental design and to address the basic problems of control, leakage and noise. The team was happy to discover that they could solve all of the basic problems by designing the valves with the highest precision possible, with clearances of 50 millionths of an inch.
"There are only a handful of machinists who can make valves with this precision. We found one and asked him to make them with the highest precision possible, which is actually higher than he can measure," says Goldfarb. "Normally in projects like this the surprises are unpleasant, but this was a pleasant one. The valves didn't leak, click or hiss!"
After getting the arm working with cold gas, the engineers tore it down and rebuilt it to operate on "hot gas" - steam that is heated to 450 degrees Fahrenheit by the hydrogen peroxide reaction.
Do watch the video and find more details at Vanderbilt's Exploration Journal...
Press release: Rocket-powered mechanical arm could revolutionize prosthetics ...
Flashbacks (related DARPA projects): Bionic Arm 2.0, Watch Out Dean Kaman ...; Utah Electrode Array to Control Bionic Arm ...
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Tuesday, July 24, 2007
PowerFoot One: Active Ankle-foot Prosthesis from MIT Unveiled
Yesterday at the Veterans Affairs Medical Center in Providence, R.I., a group of researchers and engineers from MIT and Brown University unveiled a novel robotic ankle that not only provides a prosthesis to stand or walk on, but also "propels users forward using tendon-like springs and an electric motor." We have originally reported about this device in February 2005, when it was in an early prototype stage. Now, according to Reuters, the device should become commercially available in Summer 2008 through a recently formed iWalk, Inc., based in Cambridge, Mass.
From the MIT press office:
Garth Stewart, 24, who lost his left leg below the knee in an explosion in Iraq, demonstrated the new powered ankle-foot prosthesis during a ceremony at the Providence, R.I., Veterans Affairs Medical Center. Stewart walked in the device, which, unlike any other, propels users forward using tendon-like springs and an electric motor. The prototype device reduces fatigue, improves balance and provides amputees with a more fluid gait. It could become commercially available as early as the summer of 2008.MIT Media Lab Professor Hugh Herr and his team of researchers developed the ankle-foot. Herr, NEC Career Development Professor and head of the biomechatronics research group at the Media Lab, is a VA research investigator. He is also a double amputee who tested his invention: "This design releases three times the power of a conventional prosthesis to propel you forward and, for the first time, provides amputees with a truly humanlike gait," Herr said.
"It's wild," he said, "like you're on one of those moving walkways in the airport."
Because conventional prostheses only provide a passive spring response during walking, they force the amputee to have an unnatural gait and typically to expend some 30 percent more energy on walking than a non-amputee. The new ankle is light, flexible, and -- most importantly -- generates energy for walking beyond that which can be released from a spring alone.
This is accomplished through a device equipped with multiple springs and a small battery-powered motor. The energy produced from the forward motion of the person wearing the prosthesis is stored in the power-assisted spring, and then released as the foot pushes off. Additional mechanical energy is also added to help momentum.
Press release: Joint effort: Robotic ankle research gets off on the right foot ...
VIDEO of the device...
iWalk...
Flashbacks: 'Embracing the Artificial Limb' ; Go-Go-Gadget Exoskeleton
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Thursday, July 5, 2007
Bionic Arm Uses Elephant's Trunk as Design Model
Hung like an elephant's...arm. That's right, German engineers are taking a page from mother nature and modeling their new bionic arm after the anatomy of an elephant's trunk.
It is long, gray, soft and - endowed with no fewer than 40,000 muscles - extremely agile. An elephant uses its trunk to grasp objects and for drinking. With their trunks, the pachyderms can tear down trees and pull heavy loads, and yet are also capable of performing extremely delicate manipulations. Researchers at the Fraunhofer Institute for Manufacturing Engineering and Automation IPA in Stuttgart have used the elephant's trunk as a design model. "Its suppleness and agility gave us the idea for a bionic robot arm, ISELLA," recounts Harald Staab, the IPA researcher who invented and developed the technology.Robot arms often present a risk to human operators - a technical hitch can provoke wild, uncontrolled movements. Not so ISELLA. Whereas conventional robot arms have only one motor to drive each articulated joint, ISELLA has two, grouped in pairs so that if one motor control should fail, the second takes over to prevent uncontrolled movements. "Unlike pneumatic or hydraulic actuation systems, our robot arm has a simple, low-cost muscle, consisting of a small electric motor with a drive shaft and a cord," explains Staab. In the same way as a tendon attaches one muscle to another, the cord links two related moving parts. The drive shaft is attached to the midpoint of the cord. When the shaft turns, the cord wraps around it in both directions, forming a kind of double helix. The researchers have dubbed this DOHELIX. "The shaft is no thicker than the cord, but is strong enough to resist breaking. Consequently, it has a higher transmission ratio than a conventional geared motor," Staab explains. This has been achieved using elastic materials with a very high tear strength - the type of material used to manufacture yacht sails and hang gliders. As a result, DOHELIX is much cheaper and more energy-efficient than a system of gears. Its tensile force is many orders of magnitude greater than its own weight, and drive systems based on the DOHELIX concept can be used in applications on all scales - from micrometer-scale muscles to cranes in container seaports.
The ISELLA robot arm consists of a total of ten DOHELIX muscles, providing a flexor and an extensor for each articulated joint, four situated in the elbow and six in the upper arm. The robot arm is as flexible as a human arm. "At present we are working on the elbow," relates Staab. Possible applications for ISELLA include medical rehabilitation, for instance in therapy to restore the use of injured limbs, and low-cost, flexible prosthetic devices. Such devices could be commercially available within about two years, Staab estimates.
Watch out Dean Kamen, it looks like you might have some serious competition finally...
Fraunhofer-Gesellschaft Institute...
(hat tip: Gizmag)
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Friday, June 29, 2007
Go-Go-Gadget Exoskeleton
What happens when an MIT professor loses his legs to frostbite? He creates a set of prosthetic climbing legs that would make our analog limbs look like chopped liver. Now after developing revolutionary ankles and knees, professor Herr is working on a new type of lower body exoskeleton.
From New Scientist Tech:
If you have ever wondered why we are not all running round in robotic exoskeletons that massively increase our strength and endurance, Hugh Herr, director of the biomechatronics group at the Massachusetts Institute of Technology's Media lab, US, will happily tell you.The problem, he and his colleagues point out in the group's latest patent application, is that exoskeletons are just too heavy, and offer very limited increases in strength. In fact, were current designs ever they to fail, they could seriously hurt the wearer, they say.
Now, however, Herr's team has hit on a better way to design these systems. It involves analysing the detailed motion of the human body, and building the exoskeleton so that it exactly mimics human movement and acts in parallel to it.
The team have two designs that embody this philosophy. One transfers the weight of a backpack to an exoskeleton, which may be useful for the military or emergency services. The other transfers the weight of the wearer to the exoskeleton which could be useful for the disabled and elderly. Aliens character Ripley's robotic loader could be here sooner than you think.
From the Patent application:
An exoskeleton worn by a human user consisting of a rigid pelvic harness worn about the waist of the user and exoskeleton leg structures each of which extends downwardly alongside one of the human user's legs. The leg structures include hip, knee and ankle joints connected by adjustable length thigh and shin members. The hip joint that attaches the thigh structure to the pelvic harness includes a passive spring or an active actuator to assist in lifting the exoskeleton and said human user with respect to the ground surface upon which the user is walking and to propel the exoskeleton and human user forward. A controllable damper operatively arresting the movement of the knee joint at controllable times during the walking cycle, and spring located at the ankle and foot member stores and releases energy during walking.
(hat tip: Danger Room, Noah Shachtman)
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Tuesday, June 12, 2007
Replacing the Vestibular System With a Chip
New Scientist subscribers can read all about an implantable microchip that could bypass our own [inferior] vestibular nervous signals and help patients with certain types of balance disorders. The rest of us non-subscribers can just oohhh and ahhhh from a distance.
AN IMPLANTABLE chip could eventually restore a sense of balance to people who have lost theirs through accident or illness.To balance, we rely on input from our vestibular system; a set of fluid-filled canals in the inner ear. When we move, tiny hairs pick up disturbances in the fluid, and nerves attached to the canals transmit signals to the brain, which passes the information on to muscles controlling our eyes and posture. But the system can be damaged by impacts, a loud blast, age or infection, leading to dizziness and even an inability to walk.
Researchers have previously restored balance in animals with blocked vestibular systems using a prosthesis that transmits an electrical signal to the vestibular nerve whenever gyroscopes detect rotation of the head. However, the smallest micro-gyroscopes are over 1 centimetre long, so the whole system is too big to be implanted.
Hey NewScientist, how about some free subscription love for the traffic we throw your way?
NewScientistTech....
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Thursday, June 7, 2007
National Chiao Tun University Confuses with Lousy Press Release, Probably Establishing Intelligent Prosthetics Research Center
Ok, so none of us here can speak or write in Mandarin, so in a way we shouldn't be complaining. However, coming down the line from The China Post is the most confusing and inaccurate press release we've stumbled across in a while.
So, the gist of things doesn't go much beyond the title. They're establishing an "intelligent prosthetics" research center at National Chiao Tung University (NCTU) in Hsinchu City, which will be headed by Liu Wen-Tai, currently of UC Santa Cruz. It's unclear if they mean he's leaving UCSC, or is going to be directing from afar. Also, this Medgadgeteer knows him as Wen-Tai Liu, but we've never really understood which name is the first or last in traditional Chinese identification.
They go on to say he's been "working on electronic eyes" for years. That's a bit of a stretch, as he's been part of an engineering research center involving the Doheny Eye Institute's Artificial Retina Project. So...not so much the "electronic eye" as the electronics engineering expert of a research team that has an electrode array that stimulates the eye.
The first generation of electronic eye -- developed and tested in the United States -- employs a 16-pixel chip as an artificial light receptor. When implanted into the eye, the device can replace a dysfunctional retina, providing partial vision t