Journal of NeuroEngineering and Rehabilitation<\/a>.<\/p>\n\u201cOur study is significant because evidence was previously lacking for benefits of robotic knees over advanced passive knees, which is a big reason insurance companies don\u2019t typically cover robotic knees. Our results begin to provide this evidence.\u201d<\/p>\n
In this initial study, the researchers focused on key activities of daily living in which a powered prosthesis could provide meaningful benefits compared to passive knee prostheses. Study participants repeatedly sat and stood; walked quickly on a treadmill; and repeatedly sat in a chair, walked, and sat down again.<\/p>\n
Prosthesis users who required extra walking assistance, such as a cane, found that the Power Knee offered significant help in all these tasks. Those who get around more easily on their own prostheses saw the most improvement in their gaits when Gregg\u2019s team implemented their own control algorithm on \u00d6ssur\u2019s leg. One recent amputee described it as the closest they\u2019d felt to two-legged walking on a prosthesis.<\/p>\n
\u201cOur goal in prosthesis control is to make the leg behave as close as possible to the missing human limb in order to prevent compensations that often lead to overuse injuries. It also matters because gait deviations can bring unwanted attention to some users,\u201d says Kevin Best, a research associate in robotics, recent robotics PhD graduate, and first author of the study.<\/p>\n
The team investigated two fundamentally different control approaches. \u00d6ssur\u2019s more conventional controller relies on recognizing specific features of the user\u2019s motion, indicating what they\u2019re about to do. This makes the system very safe and predictable but may not always keep up with the user\u2019s intent, Gregg says. In order to sit, users have to wait for the knee to recognize the sitting motion before it will bend, and likewise with standing.<\/p>\n
In contrast, the control approach developed by Gregg\u2019s team continually adjusts to the user\u2019s motion. They built mathematical models of how humans move, based on large datasets of unimpaired individuals. At each moment in time, their control algorithm measures the user\u2019s thigh motion to determine the right behavior, creating more natural knee motions that are better synchronized with the user.<\/p>\n
\u201cWith the improvements in robotic devices, it is clear that robotic prostheses offer great promise to the amputee population,\u201d says Jeff Wensman, a certified prosthetist\/orthotist at Michigan Medicine and study coauthor.<\/p>\n
\u201cI am excited to see the advancement of a strategy to provide powered prosthesis users with user-synchronized control. I believe that this is a missing link to making powered prosthetics a reality for amputees.\u201d<\/p>\n
This new control algorithm is harder to learn after using a conventional prosthesis for years, but the repeated sit-to-stand trials showed that participants were learning. Rather than getting more tired with each trial, they got faster. Then while walking, the more mobile group showed two improvements that could become significant benefits.<\/p>\n
First, they lifted the toe of the prosthetic foot higher, reducing the risk of tripping over small obstacles or rougher terrain. Second, they didn\u2019t need to swing their hips as hard to move the prosthetic leg forward, hinting that the powered knee and lifelike control algorithm could potentially reduce back pain and allow users to go farther before getting tired, though the team couldn\u2019t measure this with the short study.<\/p>\n
Next, the team hopes to demonstrate the safety and effectiveness of their control algorithm with stairs and ramps, followed by take-home tests. With more time to practice, the participants may be able to achieve even more. If the control strategy is successful, \u00d6ssur could incorporate aspects of it into its own algorithm.<\/p>\n
For now, the improvements with \u00d6ssur\u2019s own algorithm were enough for two of the study participants to switch to the Power Knee for their everyday prosthesis, demonstrating that robotic prostheses are moving from laboratory exploration to real-world benefit.<\/p>\n
Primary funding by the National Institutes of Health was under award No. R01HD094772, with additional support from the National Science Foundation. \u00d6ssur provided initial financial support and may have a financial interest in the results.<\/p>\n
The team has applied for patent protection for their controller with the assistance of U-M Innovation Partnerships.<\/p>\n
Source: University of Michigan<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"Share this Article You are free to share this article under the Attribution 4.0 International license. A commercial…\n","protected":false},"author":2,"featured_media":109368,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[77],"tags":[18,19,17,68198,133],"class_list":{"0":"post-109367","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-eire","9":"tag-ie","10":"tag-ireland","11":"tag-prostheses","12":"tag-science"},"share_on_mastodon":{"url":"","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/109367","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/comments?post=109367"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/109367\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media\/109368"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media?parent=109367"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/categories?post=109367"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/tags?post=109367"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}