New prosthetic foot to help tackle tough terrain

scientists have developed a more stable prosthetic foot which they say could make challenging terrain more manageable for people who have lost a lower

The new design has a kind of tripod foot that responds to rough terrain by actively shifting pressure between three different contact points.

“Prosthetic emulators allow us to try lots of different designs without the overhead of new hardware,” said Steven Collins, an at University in the US.

“Basically, we can try any kind of crazy design ideas we might have and see how people respond to them,” he said, without having to build each idea separately, an effort that can take months or years for each different design.

People with a amputation are five times more likely to fall in the course of a year, which may contribute to why they are also less socially engaged.

A better prosthetic limb could improve not just mobility but overall quality of life as well, according to the study published in the journal IEEE Transactions on

One area of particular interest is making prosthetic limbs that can better handle rough ground.

The solution, researchers thought, might be a tripod with a rear-facing heel and two forward-facing toes.

Outfitted with position sensors and motors, the foot could adjust its orientation to respond to varying terrain, much as someone with an intact foot could move their toes and flex their ankles to compensate while walking over rough ground.

Rather than building a prosthetic limb someone could test in the real world, the team, including graduate student and Alexandra Voloshina, instead built a basic tripod foot.

They then hooked it up to powerful off-board motors and computer systems that control how the foot responds as a user moves over all kinds of terrain.

The team can put their design focus on how the should function without having to worry about how to make the device lightweight and inexpensive at the same time.

The team reported results from work with a 60-year-old man who lost his below the knee due to diabetes.

The early results are promising — making the team hopeful they can take those results and turn them into more capable

“One of the things we are excited to do is translate what we find in the lab into lightweight and low power and therefore inexpensive devices that can be tested outside the lab,” Collins said.

“And if that goes well, we’d like to help make this a product that people can use in everyday life,” he said.

Source of the Article: business-standard.com

Prosthetic leg for Amputees designed by Jae-Hyun An to encourage new genre of ballet

Source of the Article: Dezeen.com
Prosthetic ballet leg for amputees encourages new genre of dancePratt Institute graduate Jae-Hyun An has created a prosthetic leg that allows amputees to perform ballet like never before. Unlike regular artificial limbs, which are designed to mimic the human body, the Marie-T enables amputee ballet dancers to enhance their performance. Made up of three components, Marie-T features a weighty foam-injected rotational moulded foot, with a stainless-steel toe and rubber grip that help provide the dancer with balance and momentum during rotations.

In mainstream ballet, dancers typically move in and out of the pointe position – when all body weight is supported by the tips of fully extended feet within pointe shoes. However, because of the immense strain on the foot and ankle of a performer, it is impossible for a ballet dancer to constantly perform in this position. Jae-Hyun An, who studied on the Pratt’s Industrial Design programme, designed the carbon-fibre Marie-T to enable amputees to dance on pointe throughout a performance.Jae-Hyun An designs prosthetic leg for ballet called Marie-T

New York-based An said the design, which is named after 19th-century Swedish ballet dancer Marie Taglioni, could encourage amputees to develop a new choreography that has never been achieved by mainstream ballerinas. “I wanted to explore what would happen if you could allow a person to perform on pointe 100 per cent of the time,” said An, who developed Marie-T over the course of four months. “How would ballet change? I wanted to create a tool for someone to take and let their imagination define the capabilities of the product.”

Prosthetic ballet leg for amputees encourages new genre of dance

During research, An realised that a weak ankle can twist and cause a ballerina in pointe position to wobble. In response, An designed a strong and stable ankle area that helps the ballerina stay in balance. The ankle connects to a slightly curved carbon-fibre limb which helps absorb the shock from the impact of the ballet dancer stepping forward. The limb is topped by a 3D-printed socket with steel round head screws. Ill-fitting prosthetic limbs can cause blisters and rashes on dancers, so An designed the Marie-T so that the parts can be easily switched out when they become well worn or need to be resized. The designer told Dezeen: “Prosthetics by itself is such a powerful and inspirational design. Any form of it is really amazing! Whether it is Hugh Herr’s bionic legs from the Biomechatronics Group in MIT, or the Flex-Foot Cheetah Leg from Ossur, or even a peg leg from… whenever.”

“It is inspiring because the technology is incredible but even more so because of the immense struggle an amputee has to overcome to use these products. Some argue that some of these prostheses give amputees a certain advantage in specific tasks, but I am not sure they would say the same if they ever saw how much training and care it takes to handle a prosthesis,” he continued.

“In my research I came across Viktoria Modesta and she re-interpreted performance with her prosthetics. It was visually so powerful and opened a completely new area of prosthetics for me. I fell in love with the idea of designing something that could expand the artistic and cultural scene of a community with prosthetic users.”

Prosthetic ballet leg for amputees encourages new genre of dance

Endolite Invests in Expanded US Sales Organization

Endolite Invests in Expanded US Sales Organization

Following continued growth in its US prosthetics business, Endolite is pleased to announce the expansion of its sales organization in order to better service its US customers.

John Braddock has been appointed Vice President of Sales and Marketing, effective April 1, 2019. John will be responsible for overseeing all commercial aspects of the US business, including the sales team, customer services, field-based clinical education and marketing.  John has been with Endolite for over 5 years and was most recently the National Sales Manager for Endolite and before that, the West Regional Sales Manager.

Brad Mattear (LO, CPA, CFo) joins Endolite as National Account Manager.  Brad previously worked for Cascade Orthopedic Supply, Inc. as the Central US & National Strategic Account Manager and most recently as the Vice President of Orthotics and Business Development for Nabtesco Proteor USA.

Roxanne Owens joins Endolite as Regional Manager – West. Roxanne will be responsible for overseeing a team of 8 Territory Managers, covering the west region.  Roxanne previously worked for Ossur as a Clinical Account Manager, Senior Area Manager, Regional Sales Manager and most recently as the Sr. Vice President of Sales and Marketing for CKI Locker LLC dba American Locker.

Finally Bryce Mathews joins Endolite as Territory Manager, responsible for sales in southern Illinois and Indiana.  Bryce previously worked as Territory Sales Manager and Senior Territory Manager for Thuasne USA.

John Braddock commented, “Endolite’s US business continues to grow and it’s important we are able to maintain a high level of customer service, both personally in the field and from our base in Ohio.  We are excited about adding to our team in key locations and look forward to continuing to build valuable partnerships with our customers across the country.”

About Endolite and Blatchford:

Endolite is part of the Blatchford Group, a UK-based, world-leading rehabilitation provider with clinical expertise in prosthetics, orthotics, special seating and wheelchairs. With offices in the UK, USA, France, Germany, Norway and India, Blatchford designs and manufactures the multi award-winning Endolite range of lower limb prostheses and provides clinical services to civilian, military and international patients.  With 128 years of expertise in innovation, it produces the world’s most advanced microprocessor-controlled artificial limbs.­­­­­

Breakthrough implant brings dexterity and sense of touch to prosthetic hand

Breakthrough implant brings dexterity and sense of touch to prosthetic hand

There have been significant technological developments in prosthetics in recent years. However, artificial replacements provide limited value in performing everyday tasks where their sensory feedback offers poor functionality. Thanks to the EU-funded DeTOP project, scientists have developed a new implant system enabling the use of a clinically viable, dexterous and sentient prosthetic hand in real life.

As summarised in a news item on the project website after trailblazing surgery a female Swedish patient became the first recipient of titanium implants “in the two forearm bones (radius and ulnar) from which electrodes to nerves and muscle were extended to extract signals to control a and to provide tactile sensations.”

The same item emphasises that traditional “prosthetic hands rely on electrodes placed over the skin to extract control signals from the underlying stump muscles. These superficial electrodes deliver limited and unreliable signals that only allow control of a couple of gross movements (opening and closing the hand).” It also notes that current artificial hands “do not provide tactile or kinesthetic sensation, so the user can only rely on vision while using the prosthesis.” This limits the ability of the user to understand the strength of his or her grip. “Richer and more reliable information can be obtained by implanting electrodes in all remaining muscle in the stump instead.” In the Swedish patient, a total of 16 electrodes were connected to nerves that would have led to the missing hand.

When electrodes are implanted using this technique, “researchers can electrically stimulate these nerves in a similar manner as information conveyed by the biological hand.” Thus, the patient can feel “sensations originating in the new prosthetic hand” with the help of “sensors that drive the stimulation of the nerve to deliver such sensations.”

From laboratory to everyday life

Project partner Integrum AB and Chalmers University of Technology have previously shown that control of a similar prosthesis in daily life was possible in above-elbow amputees as demonstrated in a video. The DeTOP news item points to the challenges involved with the process: “This was not possible in below-elbow amputees where there are two smaller bones rather than a single larger one as in the upper arm. This posed several challenges on the development of the implant system. On the other hand it also presents an opportunity to achieve a more dexterous control of an artificial replacement. This is because many more muscles are available to extract neural commands in below-elbow amputations.”

According to the news item, the patient is currently undergoing a rehabilitation programme to strengthen her forearm bones. She’s also relearning how to control her missing hand, employing prior to fully using the actual prosthetic hand. Two more patients in Italy and Sweden are lined up for such implant surgery.

The ongoing DeTOP (Dexterous Transradial Osseointegrated Prosthesis with neural control and sensory feedback) project “targets people with reduced or absent sensorimotor capabilities due to an amputation” as stated on CORDIS. It adds: “Core of the system is an osseointegrated human-machine gateway (OHMG) able to create bidirectional links between a human and a robotic prosthesis.”

Source of the Article: medicalexpress.com

Capturing Touch for Prosthetic Limbs Through Artificial Skin

RESEARCH
Luke E. Osborn and Nitish V. Thakor

Those living with upper limb differences face numerous challenges, including lost limb movement and dexterity as well as missing sensory information during object manipulation. From a user’s perspective, upper limb prostheses still have several issues with control, general discomfort from the socket, and lack of sensory feedback 1. Significant efforts have resulted in sophisticated algorithms for decoding intended prosthesis movements along multiple degrees of freedom that have enabled amputees to regain more dexterous prosthesis control 2. Another seminal advancement is targeted muscle reinnervation surgery 3, which targets nerves to different intact muscle groups such as on the chest to provide a source of well differentiated myoelectric signals for prosthesis control.

Lack of sensory information and feedback has limited the perceptual capability of the amputees. Major advancements were made in 2014 when researchers used implanted stimulating electrodes to provide sensory information back to an upper limb amputee for detecting different objects during grasping 4, conveying pressure information to complete dexterous manipulation of a fragile object 5, and general tactile activation 6.

Touch Complexity

Sensory information, specifically touch, is an extremely complex and multifaceted percept that remains difficult to completely capture. Thousands of receptors in our hands work together to pass tactile information from our fingertips to the spinal cord and into the somatosensory regions of the cortex. For upper limb amputees, the peripheral nerves and feedback to the brain still exist, but these pathways are disrupted at the receptor level in the residual limb. Researchers can take advantage of the remaining intact neural pathways to provide some element of tactile information back to an amputee. One challenge is how to convey specific tactile information by stimulating remaining peripheral nerves either through the skin or directly. However, the disrupted distribution of the receptors in the amputee’s skin and their complex tactile encoding, both individually and as a population, make it hard to replicate complex touch sensations.

Tactile information is captured by various receptors in the skin. Mechanoreceptors are responsible for our ability to perceive sensations such as pressure, texture, vibration, and stretch whereas muscle spindles and Golgi tendons drives our innate ability to perceive position (i.e. proprioception). Thermoceptors convey sensations of temperature while nociceptors enable us to feel mechanical pain, such as a sharp prick or a cut 7. Researchers have been able to provide sensory percepts of pressure 4,5,8, vibrations 8, texture 9, illusory movements 10, and now even pain 11 to upper limb amputees. Extensive knowledge gained from studying skin receptor properties has spurred the development of artificial electronic skin (e-skin) and more specifically the electronic dermis (e-dermis).

Artificial Skin

Researchers have previously developed artificial electronic skins that take advantage of the developments in flexible electronics12,13 to produce e-skins. In one such implementation, the digital mechanoreceptor inspired sensor translates pressure into oscillatory spikes 14, and in another implementation the oscillatory output drives nerve stimulation of an artificial afferent in an invertebrate 15. Most advances in sensors and artificial skins are focused on materials and electronics and typically do not incorporate sensory feedback to a prosthesis or amputee. For upper limb prostheses, one challenge is translating the response of an artificial skin into meaningful sensory information to the user by mimicking the natural sensory encoding of touch.

E-dermis for Perception of Touch and Pain

Using biology as a model, we developed a multilayered electronic dermis (e-dermis) for capturing a range of tactile perceptions at the fingertips of a prosthetic hand. We implemented a neuromorphic model to transform the e-dermis measurements to biologically relevant spiking activity for nerve stimulation, which was then used for transcutaneous electrical nerve stimulation (TENS) to provide sensory feedback (Fig. 1A). A neuromorphic system is one that attempts to mimic components of a neural system through digital signals, in this case representing touch. The idea behind this implementation is to try and capture actual receptor characteristics to convey tactile information to an amputee.

The e-dermis mimics the skin and its receptors in several ways: it has an array of sensors (receptors); the sensors are arranged over multiple layers (Fig. 1B); it produces receptor like signals; and it encodes sensor information the manner encoded by nerves. The e-dermis was made up of piezoresistive fabric (Eeonyx), which was placed between intersecting conductive traces (LessEMF) to create pressure sensitive taxels. A 1-mm layer of silicone rubber (Dragon Skin 10, Smooth-On) was added between the epidermal and dermal layers of the e-dermis and a 2-mm rubber layer added protection and compliance to the fingertip e-dermis.

Our goal was to model the skin and its receptors, and to mimic the range of perceptions from light touch to noxious, or painful. To detect pressure and pain, we treated the epidermal (upper) layer of the e-dermis as a nociceptor and the sensing elements in the dermal (bottom) layer as mechanoreceptors. The neuromorphic output from the e-dermis was then used as the stimulation signal for sensory feedback.

To understand the sensory perceptions perceived by an amputee during nerve stimulation. We performed sensory mapping of the phantom hand of one amputee as well as a quantification of the various sensory perceptions, including discomfort resulting from stimulation at a noxious level produced by controlling different stimulation parameters. Additional details can be found in 11.

To evaluate the ability of the amputee wearing the prosthesis to differentiate between tactile pressure and pain, we used 3 objects of varying curvature for a simple prosthesis grasping task (Fig. 2A). The prosthesis was able to reliably detect pain when grasping the sharpest item (Fig, 2B). Indeed, the prosthesis responded with a reflex to drop the object, similar to what happens in biology when we experience pain (i.e. withdrawal reflex). In another experiment where the user’s vision was occluded from the object being grasped, the sharper object was perceived by the user as being more painful (Fig. 2C).

One question that should be addressed: why pain? Our perception of pain is valuable because it protects our bodies by conveying information on things in our environment that are potentially damaging or harmful. A prosthetic arm doesn’t have this ability. Our recent research investigated how the idea of sensing pain could potentially benefit a prosthesis user. Because a prosthesis doesn’t have the ability to heal itself, we created a prosthesis pain reflex to compliment the sensory information being sent back to the user. In a way, this additional sensation of pain enables the prosthesis itself to become a little more lifelike and “self-aware” in its ability to understand the environment. At the same time, the tactile information being sent back to the user hopefully helps create a more realistic and feature-rich sensation of touch.

The combination of the biologically inspired e-dermis with neuromorphic stimulation models attempts to capture some of the nuanced characteristics of natural receptors, specifically those that convey innocuous and noxious signals. As upper limb prostheses continue to advance we turn to the human body as a template for developing sophisticated sensors and techniques for making these prosthetic devices more lifelike. Recreating the complex sensation of touch requires continued research of how nerve stimulation is perceived by a prosthesis user as well as how we can more accurately convey artificial neural signals that can be perceived as natural sensations.

Acknowledgements

This work was partially funded by the Space@Hopkins funding initiative through Johns Hopkins University. The results of this study were published in the June 2018 edition of Science Robotics:

Osborn, L. E., Dragomir, A., Betthauser, J. L., Hunt, C. L., Nguyen, H. H., Kaliki, R. R., & Thakor, N. V. Prosthesis with neuromorphic multilayered e-dermis perceives touch and pain. Science Robotics, 2018;3(19):eaat3818. DOI: 10.1126/scirobotics.aat3818.

References

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Biography

Luke Osborn
Luke Osborn, MSE, is a PhD student in biomedical engineering at Johns Hopkins University. His research in the Neuroengineering and Biomedical Instrumentation Lab focuses on developing tactile sensing technologies, neuromorphic modeling of sensory information, and sensory feedback for upper limb prostheses. He is a student member of the IEEE.

Nitish Thakor
Nitish Thakor, PhD, is a professor of biomedical engineering, electrical and computer engineering, and neurology at Johns Hopkins and directs the Laboratory for Neuroengineering. He is also the director the Singapore Institute for Neurotechnology (SINAPSE) at the National University of Singapore. His research focus is in the field of neuroengineering, including neural diagnostic instrumentation, neural microsystems, neural signal processing, optical imaging of the nervous system, neural control of prostheses, and brain-machine interfaces. He is a recipient of a Research Career Development Award from the National Institutes of Health and a Presidential Young Investigator Award from the US National Science Foundation. He is a founding fellow of the Biomedical Engineering Society and fellow of the IEEE.

About BrainInsight

BrainInsight, the IEEE Brain Initiative eNewsletter, is a quarterly online publication, featuring practical and timely information and forward-looking commentary on neurotechnologies. BrainInsight describes recent breakthroughs in research, primers on methods of interests, or report recent events such as conferences or workshops.


IEEE
Source of the article: Brain.ieee.org

Solar-powered synthetic skin could give robots a sense of touch and allow amputees to feel again

Synthetic skin capable of touch sensitivity could make smart prosthetic hands more useful for amputees