Ghost Dance is a research project out of Lusófona University that sets out to explore the value of human connection and how it can be recreated with a virtual dance partner. Project directors Cecilia de Lima and Rui Antunes looked to inertial motion capture to create fluid motions that real-life dancers could perform alongside. Challenge: The Ghost Dance team needed to build a 3D model based on dancers' movements to test the relationship between virtual and real-life performers. Creating a realistic model posed a significant challenge. Solution: Inertial motion capture technology allowed dancers to record an entire routine with maximum comfort and accuracy. The result was a virtual partner with smooth motions, making for a natural performance with its real-life counterpart.Key takeaways <ul><li>A diverse range of motion: Even complex movements in contemporary dance can be tracked with inertial sensors</li><li>Efficient recording: Entire choreographed performances were recorded quickly, to work around time restrictions in the dance studio</li><li>Comfortable wear: Dancers could perform unobstructed thanks to the adjustable nature of Xsens wearable technology</li><li>Fluid results: The virtual dance partner moved smoothly, creating a high sense of realism during the performance</li></ul>Studying the importance of human touchBefore beginning the project, the <a href="https://ghostdance.ulusofona.pt/outcomes/publications" target="_blank" rel="noopener noreferrer">Ghost Dance</a> directors had two main goals. “The first was to understand the need for physical, bodily presence between humans,” says Rui Antunes, Director. “In the new era of technology, we seem to be growing further apart, and we wanted to see whether this had an impact on our wellbeing.” To explore this, the team planned to use VR goggles to compare dancing with a human partner and a virtual counterpart. “We wanted to find out what happens when a human body interacts with a virtual entity,” explains Cecilia de Lima, Director. “We knew it would make for a completely different experience, but we needed to find out how and why.” The other part of Cecilia and Rui’s project was to see if virtual dance partners could improve via machine learning. The digital counterparts were created from the dancer’s movements, but they wanted to see if they could develop their own routines based on the information provided.To achieve these goals, extensive planning was put into place to find the right technology.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1742888563673-Ghost+dance+Performance+Dancing+a+duet+with+avatar+2.jpg" style="width:100%px" class="fr-fic fr-dib" />Building a virtual dance partner This complex project required not only a skilled team, but a set of specialized technology to record the dancers’ performances and transform them into a digital counterpart.Dancers use movements that aren’t typical in day-to-day life, so it was crucial to have a motion capture system to accommodate that complexity. “The Xsens system could accurately record their movements for a perfect translation into a 3D model,” says Rui. Inertial sensors contain accelerometers and gyroscopes, tracking the joint rotation and velocity of the subject. This pinpoint precision allowed for lifelike movements in the virtual dance partner, making a more natural experience for the real-life dancers.“Comfort is essential when dancing,” explains Cecilia. “We needed the motion capture technology to be unobtrusive to get the best results.” The system consists of 17 sensors, which all strap individually onto the body, making each one adjustable to the wearer’s preferences. Having this comfort led to more natural, fluid moves to create the virtual partner. <img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1742888595821-Ghost+dance+Motion+Capture+for+Avatar+Dance+duets+7.jpg" style="width:100%px" class="fr-fic fr-dib" />Machine learning for virtual dance partnersAfter the dancers were recorded and the virtual partners were made, Cecilia and Rui needed to see whether they could develop from the base-level data. To do this, they created machine-learning algorithms to put the models to the test.A machine cannot make subjective decisions, so the team found a solution to objectify and quantify the dancers’ movements. “The eight Laban efforts are commonly used in theatre and dance classes to expand students’ creativity,” says Cecilia. “These are basic movements, including punching, wringing, and pressing, that a robot could easily identify.”From this information, Cecilia and Rui hope to develop a virtual dance partner that can make its own organic moves in time with a real-life dancer. “Inertial motion capture was the perfect choice for this type of research,” continues Rui. “We had a well-built model that was based on real movement, which provided a baseline for machine learning.”“The research project was incredibly enlightening on the importance of human connection,” concludes Cecilia. “Virtual dance partners are not currently able to replace real ones.” Small sensations, such as breaths and footsteps, are vital when dancing cohesively with a partner. At this stage of technology development, these nuances are not available digitally. However, that’s not to say it won’t happen in the future. Ghost Dance proved that in the future, this could be a feasible alternative to dancing with a real counterpart. It seems increasingly possible when using inertial motion capture to create the basis of the digital partner.Using Xsens meant that the dancers could perform freely, with no need to adjust choreography. This led to an optimal experience when dancing with a virtual partner. <img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1742888642787-Ghost+dance+Overlay+of+virtual+and+real+partners+dancing+3.png" style="width:100%px" class="fr-fic fr-dib" />

With Inertial Motion Capture

Ghost Dance: Building a virtual dance partner

One year after Unitree H1 (1.8m) pioneered the first standing backflip by an electric humanoid robot (March 2024). Meet the Unitree G1 – now flawlessly conquering an even more challenging standing side flip. (Zero malfunctions/damage occurred during programming and filming.)

One year after Unitree H1 (1.8m) pioneered the first standing backflip by an electric humanoid robot (March 2024). Meet the Unitree G1 – now flawlessly conquering an even more challenging standing side flip. (Zero malfunctions/damage occurred during programming and filming.)

World's First Side-Flipping Humanoid Robot: Unitree G1

It’s difficult to build devices that replicate the fluid, precise motion of humans, but that might change if we could pull a few (literal) strings.At least, that’s the idea behind “cable-driven” mechanisms in which running a string through an object generates streamlined movement across an object’s different parts. Take a robotic finger, for example: You could embed a cable through the palm to the fingertip of this object and then pull it to create a curling motion.While cable-driven mechanisms can create real-time motion to make an object bend, twist, or fold, they can be complicated and time-consuming to assemble by hand. To automate the process, researchers from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) have developed an all-in-one 3D printing approach called “Xstrings.” Part design tool, part fabrication method, Xstrings can embed all the pieces together and produce a cable-driven device, saving time when assembling bionic robots, creating art installations, or working on dynamic fashion designs.3D printing approach strings together cable-driven mechanisms for you Video: MIT CSAILIn a <a href="https://groups.csail.mit.edu/hcie/files/research-projects/xstrings/xstrings.pdf" target="_blank">paper</a> to be presented at the 2025 Conference on Human Factors in Computing Systems (CHI2025), the researchers used Xstrings to print a range of colorful and unique objects that included a red walking lizard robot, a purple wall sculpture that can open and close like a peacock’s tail, a white tentacle that curls around items, and a white claw that can ball up into a fist to grab objects.To fabricate these eye-catching mechanisms, Xstrings allows users to fully customize their designs in a software program, sending them to a multi-material 3D printer to bring that creation to life. You can automatically print all the device’s parts in their desired locations in one step, including the cables running through it and the joints that enable its intended motion.MIT CSAIL postdoc and lead author Jiaji Li says that Xstrings can save engineers time and energy, reducing 40 percent of total production time compared to doing things manually. “Our innovative method can help anyone design and fabricate cable-driven products with a desktop bi-material 3D printer,” says Li.<h2>A new twist on cable-driven fabrication</h2>To use the Xstrings program, users first input a design with specific dimensions, like a rectangular cube divided into smaller pieces with a hole in the middle of each one. You can then choose which way its parts move by selecting different “primitives:” bending, coiling (like a spring), twisting (like a screw), or compressing — and the angle of these motions.For even more elaborate creations, users can incorporate multiple primitives to create intriguing combinations of motions. If you wanted to make a toy snake, you could include several twists to create a “series” combo, in which a single cord drives a sequence of motions. To create the robot claw, the team embedded multiple cables into a “parallel” combination, where several strings are embedded, to enable each finger to close up into a fist.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1742432637463-mit-Xstrings-diagram.png" style="width:100%px" class="fr-fic fr-dib" />Xstrings facilitates how cables are integrated into the object it’s producing. Users can choose exactly how the strings are secured, including its endpoint, the holes within the structure that the cord passes through, and where you’d pull to operate the device.  Image courtesy of the researchers.Beyond fine-tuning the way cable-driven mechanisms move, Xstrings also facilitates how cables are integrated into the object. Users can choose exactly how the strings are secured, in terms of where the “anchor” (endpoint), “threaded areas” (or holes within the structure that the cord passes through), and “exposed point” (where you’d pull to operate the device) are located. With a robot finger, for instance, you could choose the anchor to be located at the fingertip, with a cable running through the finger and a pull tag exposed at the other end.Xstrings also supports diverse joint designs by automatically placing components that are elastic, compliant, or mechanical. This allows the cable to turn as needed as it completes the device’s intended motion.<h2>Driving unique designs across robotics, art, and beyond</h2>Once users have simulated their digital blueprint for a cable-driven item, they can bring it to life via fabrication. Xstrings can send your design to a fused deposition modeling 3D printer, where plastic is melted down into a nozzle before the filaments are poured out to build structures up layer by layer.Xstrings uses this technique to lay out cables horizontally and build around them. To ensure their method would successfully print cable-driven mechanisms, the researchers carefully tested their materials and printing conditions.For example, the researchers found that their strings only broke after being pulled up and down by a mechanical device more than 60,000 times. In another test, the team discovered that printing at 260 degrees Celsius with a speed of 10-20 millimeters per second was ideal for producing their many creative items.“The Xstrings software can bring a variety of ideas to life,” says Li. “It enables you to produce a bionic robot device like a human hand, mimicking our own gripping capabilities. You can also create interactive art pieces, like a cable-driven sculpture with unique geometries, and clothes with adjustable flaps. One day, this technology could enable the rapid, one-step creation of cable-driven robots in outer space, even within highly confined environments such as space stations or extraterrestrial bases.”The team’s approach offers plenty of flexibility and a noticeable speed boost to fabricating cable-driven objects. It creates objects that are rigid on the outside, but soft and flexible on the inside; in the future, they may look to develop objects that are soft externally but rigid internally, much like humans’ skin and bones. They’re also considering using more resilient cables, and, instead of just printing strings horizontally, embedding ones that are angled or even vertical.Li wrote the paper with Zhejiang University master’s student Shuyue Feng; Tsinghua University master’s student Yujia Liu; Zhejiang University assistant professor and former MIT Media Lab visiting researcher Guanyun Wang; and three CSAIL members: Maxine Perroni-Scharf, an MIT PhD student in electrical engineering and computer science; Emily Guan, a visiting researcher; and senior author Stefanie Mueller, the TIBCO Career Development Associate Professor in the MIT departments of Electrical Engineering and Computer Science and Mechanical Engineering, and leader of the HCI Engineering Group.

The “Xstrings” method can produce a range of colorful and unique objects, like a white tentacle that curls around items and a purple wall sculpture that can open and close. Photo: Mike Grimmett/MIT CSAIL

“Xstrings” method enables users to produce cable-driven objects, automatically assembling bionic robots, sculptures, and dynamic fashion designs.

3D printing approach strings together dynamic objects for you

<html><head></head><body>Unlock unlimited sports potential (Extra large joint movement space angle, 23~43 joints) Force control of dexterous hands, manipulation of all thingsImitation &amp; reinforcement learning driven Robot world model, let’s create it together Unitree G1 Price from $16K (Tax and Shipping cost excluded)More introduction:&nbsp;<a tabindex="0" href="https://www.youtube.com/redirect?event=video_description&amp;redir_token=QUFFLUhqbFpMZ0ZSV05IaDdTbEZuQnlFN1B3cDgzbnY0d3xBQ3Jtc0trTXhubEF2aWpndUhNLUFQajBBdmJObEFrRmZlcWdEdTN3dm1Fdzd0LUhGeVhxRF9HUUYwdl9NM2x5UnplTlYtR05zdkxSdUhvUk0zNktiWGhvdlpkNHhpazlUOVhpNHk5dmI3cEJRWWI2U3JQWEttTQ&amp;q=https%3A%2F%2Fwww.unitree.com%2Fg1&amp;v=GzX1qOIO1bE" rel="nofollow" target="_blank" data-immersive-translate-walked="fad7c807-08d6-4a00-ad03-0c3b7086529c">https://www.unitree.com/g1</a>Official Website: www.unitree.com&nbsp;Sales contact: sales_global@unitree.cc</body></html>

AI Avatar  Price from $16K

Unitree Introducing  Unitree G1 Humanoid Agent

720° Spin Kick - Hear the Impact! Kung Fu BOT Gameplay RAW. (No Speed-Up) (Do not imitate, please keep a safe distance from the machine)

720° Spin Kick - Hear the Impact! Kung Fu BOT Gameplay RAW. (No Speed-Up) 
(Do not imitate, please keep a safe distance from the machine)

Kungfu BOT GAME

We have continued to upgrade the Unitree G1's algorithm, enabling it to learn and perform virtually any movement. What other moves would you like to see. Do share with us in the comments. (Please keep a safe distance from the robot.)

We have continued to upgrade the Unitree G1's algorithm, enabling it to learn and perform virtually any movement.What other moves would you like to see. Do share with us in the comments. (Please keep a safe distance from the robot.)

Kungfu BOT: Unitree G1

<h2 id="isPasted">What Dance Would You Like to Perform with Unitree G1?</h2>With the upgraded algorithm, G1 can learn any dance. Leave a comment to tell us what dance you'd like to see！

With the upgraded algorithm, G1 can learn any dance. Leave a comment to tell us what dance you'd like to see！

What Dance Would You Like to Perform with Unitree G1?

Hello everyone, let me introduce myself again. I am Unitree H1 "Fuxi".&nbsp;I am now a comedian at the Spring Festival Gala, hoping to bring joy to everyone.&nbsp;Let’s push boundaries every day and shape the future together.A little surprise: the handkerchief can not only spin but can also be thrown out and automatically returned to its position.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzM4MDc3NzEzOTI3LeW+ruS/oeWbvueJh18yMDI1MDEyODIzMDMzNy5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 100%px;" class="fr-fic fr-dib">

Debut at the Spring Festival Gala

Unitree H1: Humanoid Robot Makes Its Debut at the Spring Festival Gala

Unitree H1&nbsp;Deep Reinforcement Learning&nbsp;In-place Flipping Parameters:&nbsp;Weight: about 50kg&nbsp;Height: about 1.8m&nbsp;Actuator: electric motor

Deep Reinforcement Learning

Unitree H1

Unitree G1 Bionic: Agile Upgrade

With the majority of spine surgeons experiencing bodily discomfort due to their work, the need for ergonomic improvements in the healthcare industry is clear. Orthopedic spine surgeon Philip Louie is on a mission to address this issue, leveraging&nbsp;<a href="https://www.movella.com/products/motion-capture" target="_blank" rel="noopener noreferrer">Xsens motion capture</a>&nbsp;technology and Scalefit software to identify pain points and create solutions that enhance surgeons’ physical well-being and long-term performance.Challenge:&nbsp;To effectively analyze surgeons’ occupational health and safety, healthcare professional Philip Louie needed an objective dataset to define specific problem areas.Solution:&nbsp;Using the Xsens inertial motion capture and <a href="https://www.movella.com/integrations/scalefit" target="_blank" rel="noopener noreferrer">Scalefit&nbsp;</a>software provided highly accurate data on the surgeons’ movements, all while maintaining privacy for themselves and their patients.Key takeaways:<ul><li id="isPasted" style="font-weight: bold;">Advanced data accuracy for ergonomic assessment: inertial motion capture records even the smallest movements, ensuring precise analysis</li><li style="font-weight: bold;">Ensuring privacy: Camera-less technology guarantees anonymity for both patients and surgeons</li><li>Authentic movement thanks to unobtrusive technology: comfortable wearables allow ergonomic professionals to track real, natural motion</li></ul>An overwhelming 80% of spine surgeons experience bodily discomfort. This high proportion shows a need for occupational health and safety to be prioritized within the healthcare industry. Such injuries can lead to unexpected time off, declining performance, or even early retirement. <a href="https://www.linkedin.com/in/philip-louie-1605807/" target="_blank" rel="noopener noreferrer">Orthopedic spine surgeon Philip Louie</a> is conducting a study to find out how to improve surgeons’ physical well-being to make their highly technical job that little bit easier.Stopping spine surgeon injuries“The majority of healthcare professionals experience some sort of bodily discomfort due to their job,” explains Philip. “So the first part of our study was to find the physical pain points of spine surgeons.” After completing a series of intense surgeries, Philip noticed the harmful impact and the role it had on his joints and muscles.However, Philip was not the only surgeon experiencing these issues. He started the study to show that physical well-being is a profession-wide issue, not just a personal one, and with this information, hopes to build more ergonomically friendly surgery rooms. To effectively demonstrate his point, he needed objective data that put a spotlight on the exact areas for improvement in the healthcare industry.Preparing for researchPhilip decided to perform ergonomic analyses on three surgeons, each performing the same procedure ten times. “Using replicable surgeries as the basis for the study was crucial,” he says. “It allowed us to compare and contrast each dataset to identify outlying issues.” Philip then researched the different techniques for assessing occupational health and safety.“For the first attempt, we used the REBA method,” explains Philip. REBA (rapid entire body analysis) requires an ergonomics analyst to manually assess the worker’s movements, using their knowledge of physical well-being to point out issues and suggest amendments. “We found that while this was useful, we didn’t have the quantitative, set-in-stone data needed for this project.”&nbsp;An extra person in the surgery room also led to privacy issues for both patient and surgeon. Most would be uncomfortable having their work, or personal procedures, observed by a third party. Filming would also create an anonymity issue, leading to faces having to be blurred and time taken away from the investigation. After extensive research, Philip found the answer to anonymity while further improving the quality of data.Using Xsens and Scalefit technology“When we found inertial motion capture, we knew that it was the only way to efficiently carry out our research without encroaching on the privacy of others,” says Philip. Using inertial technology, the Xsens motion capture system tracks velocity, acceleration, and rotation without requiring any cameras. Instead, the data is sent directly from the wearables to post-processing software.“I was able to perform a two-hour surgery while wearing the Xsens system,” Philip continues. “By the end, myself and the other surgeons forgot we were even wearing it.” The Awinda set contains 17 wireless sensors, all individually strapped to the body for bespoke comfort. The team could also maintain a sterile environment, with the sensors tucked underneath scrubs.Using the Xsens motion data and Scalefit software, Philip could effectively collate his results to show objective findings, pinpointing the need for ergonomic improvement in the surgery room. The research team quantified this data to highlight the specific areas of a surgeon’s body that were most affected by their job. Having this abundance of data instantly available for research was essential for rapidly progressing the project.Looking aheadErgonomic analysis is best carried out in a worker’s natural environment, doing the tasks they would do every day, and Xsens allows you to do just that. “I hope to roll out this technique to the rest of the healthcare industry,” says Philip. “Its usefulness was invaluable to us, and it can help many other professionals perform their jobs more safely.”Philip’s research project is drawing to a close, and the last rounds of motion capture data are being recorded. He hopes to create tangible solutions for spine surgeons, with his ability to identify exact pain points and put together a plan to prevent them from happening, such as full-body exercises to relieve tension from the back, shoulders, wrists, and other vulnerable joints.&nbsp;Just wearing the Xsens suit raised awareness for the toll surgery takes on medical professionals. Philip could see in real time how his body was reacting to holding it in a fixed position, encouraging him to relax and avoid experiencing unnecessary pain.“Inertial motion capture technology was the only solution for this project,” concludes Philip. “Having this quantitative data is invaluable to our occupational health and safety.

With Xsens MVN Analyze

Ergonomic analysis for spine surgeons: saving your back and neck

Unitree B2 continues to evolve every day with the acceleration of AI. Is there a limit to its evolution? More introduction: www.unitree.com/b2The fastest industrial quadruped robot with a speed of 6m/s.Excellent terrain adaptability, ensuring stable driving on slippery or uneven surfaces.Excellent continuous stair climbing ability, easy to handle steps.170% increase in joint performance with 360 N.m of torque. Extreme performance provids greater flexibility and stability for industrial operations.Overcoming obstacles. Stable and tough. Superior obstacle-crossing ability, easy to cross the mess of wood piles, 40cm high platforms and other obstacles.100% increase in sustained load 200% increase in endurance.

Unitree B2 continues to evolve every day with the acceleration of AI. Is there a limit to its evolution?

Unitree B2 has evolved once again, is there an end?

In this episode, we explore an innovative prosthesis driven by the nervous system that helps people with amputations walk naturally and discover how this cutting-edge technology is transforming mobility and enhancing the quality of life for amputees by restoring a natural gait.

Podcast: Bionics Help Amputees Take Big Strides Forward

This article was discussed in our <a href="https://www.wevolver.com/profile/the.next.byte" rel="noopener noreferrer" target="_blank">Next Byte podcast</a>.&nbsp;<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/ceb16e69-0075-4e23-97b8-f679ee5b172e?dark=false" class="fr-draggable" data-gtm-yt-inspected-24="true" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe> The full article will continue below.<hr>State-of-the-art prosthetic limbs can help people with amputations achieve a natural walking gait, but they don’t give the user full neural control over the limb. Instead, they rely on robotic sensors and controllers that move the limb using predefined gait algorithms.Using a new type of surgical intervention and neuroprosthetic interface, MIT researchers, in collaboration with colleagues from Brigham and Women’s Hospital, have shown that a natural walking gait is achievable using a prosthetic leg fully driven by the body’s own nervous system. The surgical amputation procedure reconnects muscles in the residual limb, which allows patients to receive “proprioceptive” feedback about where their prosthetic limb is in space.In a study of seven patients who had this surgery, the MIT team found that they were able to walk faster, avoid obstacles, and climb stairs much more naturally than people with a traditional amputation.<iframe width="640" height="360" src="https://www.youtube.com/embed/fKdnu50Nx-8?&amp;wmode=opaque&amp;rel=0&amp;enablejsapi=1&amp;origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true" data-gtm-yt-inspected-24="true" id="651131305" title="Helping people with amputation walk naturally">&nbsp;</iframe>“This is the first prosthetic study in history that shows a leg prosthesis under full neural modulation, where a biomimetic gait emerges.&nbsp;No one has been able to show this level of brain control that produces a natural gait, where the human’s nervous system is controlling the movement, not a robotic control algorithm,” says Hugh Herr,&nbsp;a professor of media arts and sciences, co-director of the K. Lisa Yang Center for Bionics at MIT, an associate member of MIT’s McGovern Institute for Brain Research, and the senior author of the new study.Patients also experienced less pain and less muscle atrophy following this surgery, which is known as the agonist-antagonist myoneural interface (AMI). So far, about 60 patients around the world have received this type of surgery, which can also be done for people with arm amputations.Hyungeun Song, a postdoc in MIT’s Media Lab, is the lead author of the <a href="https://www.nature.com/articles/s41591-024-02994-9" target="_blank">paper</a>, which appears today in Nature Medicine.<h2>Sensory feedback</h2>Most limb movement is controlled by pairs of muscles that take turns stretching and contracting. During a traditional below-the-knee amputation, the interactions of these paired muscles are disrupted. This makes it very difficult for the nervous system to sense the position of a muscle and how fast it’s contracting — sensory information that is critical for the brain to decide how to move the limb.People with this kind of amputation may have trouble controlling their prosthetic limb because they can’t accurately sense where the limb is in space. Instead, they rely on robotic controllers built into the prosthetic limb. These limbs also include sensors that can detect and adjust to slopes and obstacles.To try to help people achieve a natural gait under full nervous system control, Herr and his colleagues began developing the AMI surgery several years ago. Instead of severing natural agonist-antagonist muscle interactions, they connect the two ends of the muscles so that they still dynamically communicate with each other within the residual limb. This surgery can be done during a primary amputation, or the muscles can be reconnected after the initial amputation as part of a revision procedure.“With the AMI amputation procedure, to the greatest extent possible, we attempt to connect native agonists to native antagonists in a physiological way so that after amputation, a person can move their full phantom limb with physiologic levels of proprioception and range of movement,” Herr says.In a 2021 <a href="https://news.mit.edu/2021/surgery-control-prosthetic-limbs-0215" target="_blank">study</a>, Herr’s lab found that patients who had this surgery were able to more precisely control the muscles of their amputated limb, and that those muscles produced electrical signals similar to those from their intact limb.After those encouraging results, the researchers set out to explore whether those electrical signals could generate commands for a prosthetic limb and at the same time give the user feedback about the limb’s position in space. The person wearing the prosthetic limb could then use that proprioceptive feedback to volitionally adjust their gait as needed.In the new Nature Medicine study, the MIT team found this sensory feedback did indeed translate into a smooth, near-natural ability to walk and navigate obstacles.“Because of the AMI neuroprosthetic interface, we were able to boost that neural signaling, preserving as much as we could. This was able to restore a person's neural capability to continuously and directly control the full gait, across different walking speeds, stairs, slopes, even going over obstacles,” Song says.<h2>A natural gait</h2>For this study, the researchers compared seven people who had the AMI surgery with seven who had traditional below-the-knee amputations. All of the subjects used the same type of bionic limb: a prosthesis with a powered ankle as well as electrodes that can sense electromyography (EMG) signals from the tibialis anterior the gastrocnemius muscles. These signals are fed into a robotic controller that helps the prosthesis calculate how much to bend the ankle, how much torque to apply, or how much power to deliver.The researchers tested the subjects in several different situations: level-ground walking across a 10-meter pathway, walking up a slope, walking down a ramp, walking up and down stairs, and walking on a level surface while avoiding obstacles.In all of these tasks, the people with the AMI neuroprosthetic interface were able to walk faster — at about the same rate as people without amputations — and navigate around obstacles more easily. They also showed more natural movements, such as pointing the toes of the prosthesis upward while going up stairs or stepping over an obstacle, and they were better able to coordinate the movements of their prosthetic limb and their intact limb. They were also able to push off the ground with the same amount of force as someone without an amputation.“With the AMI cohort, we saw natural biomimetic behaviors emerge,” Herr says.&nbsp;“The cohort that didn’t have the AMI, they were able to walk, but the prosthetic movements weren’t natural, and their movements were generally slower.”These natural behaviors emerged even though the amount of sensory feedback provided by the AMI was less than 20 percent of what would normally be received in people without an amputation.“One of the main findings here is that a small increase in neural feedback from your amputated limb can restore significant bionic neural controllability, to a point where you allow people to directly neurally control the speed of walking, adapt to different terrain, and avoid obstacles,” Song says.“This work represents yet another step in us demonstrating what is possible in terms of restoring function in patients who suffer from severe limb injury. It is through collaborative efforts such as this that we are able to make transformational progress in patient care,” says Matthew Carty, a surgeon at Brigham and Women’s Hospital and associate professor at Harvard Medical School, who is also an author of the paper.Enabling neural control by the person using the limb is a step toward Herr’s lab’s goal of “rebuilding human bodies,” rather than having people rely on ever more sophisticated robotic controllers and sensors — tools that are powerful but do not feel like part of the user’s body.“The problem with that long-term approach is that the user would never feel embodied with their prosthesis. They would never view the prosthesis as part of their body, part of self,” Herr says. “The approach we’re taking is trying to comprehensively connect the brain of the human to the electromechanics.”The research was funded by the MIT K. Lisa Yang Center for Bionics and the Eunice Kennedy Shriver National Institute of Child Health and Human Development.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzIwNDIzMTQxODg1LV9NR185NjE2LTMuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 100%px;" class="fr-fic fr-dib">Credit: Jimmy Day, MIT Media Lab

“This is the first prosthetic study in history that shows a leg prosthesis under full neural modulation,” Hugh Herr says. Image: Courtesy of Hugh Herr and Hyungeun Song

A new surgical procedure gives people more neural feedback from their residual limb. With it, seven patients walked more naturally and navigated obstacles.

A prosthesis driven by the nervous system helps people with amputation walk naturally

In this episode, we discuss how CalTech researchers have created bionic jellyfish to help us explore the oceans and better understand the impacts of climate change.

bionics

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