Medical Design and Outsourcing

  • Home
  • Medical Device Business
    • Mergers & Acquisitions
    • Financial
    • Regulatory
  • Applications
    • Cardiovascular
    • Devices
    • Imaging
    • Implantables
    • Medical Equipment
    • Orthopedic
    • Surgical
  • Technologies
    • Contract Manufacturing
    • Components
    • Electronics
    • Extrusions
    • Materials
    • Motion Control
    • Prototyping
    • Pumps
    • Tubing
  • Med Tech Resources
    • DeviceTalks Tuesdays
    • Digital Editions
    • eBooks
    • Manufacturer Search
    • Medical Device Handbook
    • MedTech 100 Index
    • Podcasts
    • Print Subscription
    • The Big 100
    • Webinars / Digital Events
    • Whitepapers
    • Video
  • 2022 Leadership in MedTech
    • 2022 Leadership Voting!
    • 2021 Winners
    • 2020 Winners
  • Women in Medtech

Cranking Up the Power Setting May Help Some Who Use Prosthetics

November 12, 2018 By University of Central Florida

Amputees who use powered prosthetic ankles may be able to avoid the energetic costs typically associated with prosthetics by cranking up the power provided by their devices.

A UCF engineering professor recently published a study in Scientific Reports that shows that people with transtibial amputations—the loss of a limb below the knee—may improve their walking ability if they change the power-setting on their devices. Hwan Choi, who received his doctorate in engineering from the University of Washington, is an assistant professor in the UCF department of Mechanical and Aerospace Engineering.

According to a study conducted by the National Institutes of Health, approximately 185,000 amputations occur in the United States every year and 49-95 percent of lower-limb amputees reportedly use a prosthesis. Most of those on the market are passive prosthetics. On average, amputees spend up to 30 percent more energy than unimpaired individuals when performing tasks such as walking. This could be due to the fact that most ankle prostheses are passive-elastic, meaning that they can store and release energy when they come in contact with the ground but are unable to perform positive net ankle work that allows for muscle shortening contractions to occur. In fact, these prostheses are only able to provide one eighth of the power of the intact gastrocnemius and soleus muscles, the key muscles that support and propel the body during walking.

As passive prostheses increase the energetic demand on the user, individuals may have to compensate by increasing muscular effort in the residual or intact limb. Powered ankle prostheses, on the other hand, use actuators to reduce the increased metabolic costs placed on amputees by delivering positive work. BiOM (now known as EMPOWER), the only commercially available powered ankle prosthetic, uses a visual display that allows the wearer to tune the power setting on the device. Ideally, they would select a power setting between 0 percent and 100 percent that best approximates that of a healthy ankle at the user’s preferred walking speed. But the question remains: how much power should the prosthesis provide?

Too little power and they may experience the same metabolic costs of those using passive prostheses, but too much and they may experience problems such as knee hyperflexion and increased energy absorption in the knee that can raise the metabolic costs of the user.

Choi, along with coauthors Kimberly Ingrahm, David Remy, Emily Gardinier, and Deanna Gates from the University of Michigan, tested ten individuals with transtibial amputations. They measured the metabolic cost of transport (COT) and the BiOM’s net ankle work at different power settings, while the amputees walked on a treadmill with the BiOM ankle.

Choi said that they discovered that the ideal power that reduced metabolic cost was actually greater than biological norms. In other words, the best tested setting actually decreased the amount of excess energy used by the subject more than the prosthetist-chosen power setting.

“The key finding of this study was that none of the subjects had the minimum metabolic cost when they walk with unimpaired individuals work or power. When they had greater power, then the impaired individuals actually reduced metabolic cost.”

Across participants, power settings greater than 50 percent resulted in lower COT, but the best tested power setting was actually higher than the prosthetist-chosen setting.

In fact, on average, the power setting that minimized energy costs corresponded to approximately double the net ankle work of the biological ankle. So while powered ankles may be more beneficial than passive prosthetics, amputees can actually increase their activity level when prosthetists change their goal from achieving approximate biological ankle kinetics to minimizing metabolic costs.

According to Choi, with minimized metabolic costs, transtibial amputees have a greater chance of remaining active, improving their quality of life, and preventing a number of health consequences, including diabetes and cardiac disease.

Related Articles Read More >

Johnson & Johnson J&J DePuy Synthes
Surgeon wins $20M verdict against J&J’s DePuy Synthes
What happens when bionic eye implants suddenly go dark?
Ossur power knee
Össur launches next-gen Power Knee
Cleveland Clinic bionic arm Paul Marasco Zachary Thumser
Cleveland Clinic reports bionic arm breakthrough

DeviceTalks Weekly.

June 24, 2022
How innovative design, commercial strategy is building Cala Trio’s bioelectronic medicine market
See More >

MDO Digital Edition

Digital Edition

Subscribe to Medical Design & Outsourcing. Bookmark, share and interact with the leading medical design engineering magazine today.

MEDTECH 100 INDEX

Medtech 100 logo
Market Summary > Current Price
The MedTech 100 is a financial index calculated using the BIG100 companies covered in Medical Design and Outsourcing.
DeviceTalks

DeviceTalks is a conversation among medical technology leaders. It's events, podcasts, webinars and one-on-one exchanges of ideas & insights.

DeviceTalks

New MedTech Resource

Medical Tubing

Enewsletter Subscriptions

Enewsletter Subscriptions

MassDevice

Mass Device

The Medical Device Business Journal. MassDevice is the leading medical device news business journal telling the stories of the devices that save lives.

Visit Website
MDO ad
Medical Design and Outsourcing
  • MassDevice
  • DeviceTalks
  • MedTech 100 Index
  • Medical Tubing + Extrusion
  • Drug Delivery Business News
  • Drug Discovery & Development
  • Pharmaceutical Processing World
  • R&D World
  • About Us/Contact
  • Advertise With Us
  • Subscribe to Print Magazine
  • Subscribe to E-newsletter
  • Attend our Monthly Webinars
  • Listen to our Weekly Podcasts
  • Join our DeviceTalks Tuesdays Discussion

Copyright © 2022 WTWH Media, LLC. All Rights Reserved. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media LLC. Site Map | Privacy Policy | RSS

Search Medical Design & Outsourcing

  • Home
  • Medical Device Business
    • Mergers & Acquisitions
    • Financial
    • Regulatory
  • Applications
    • Cardiovascular
    • Devices
    • Imaging
    • Implantables
    • Medical Equipment
    • Orthopedic
    • Surgical
  • Technologies
    • Contract Manufacturing
    • Components
    • Electronics
    • Extrusions
    • Materials
    • Motion Control
    • Prototyping
    • Pumps
    • Tubing
  • Med Tech Resources
    • DeviceTalks Tuesdays
    • Digital Editions
    • eBooks
    • Manufacturer Search
    • Medical Device Handbook
    • MedTech 100 Index
    • Podcasts
    • Print Subscription
    • The Big 100
    • Webinars / Digital Events
    • Whitepapers
    • Video
  • 2022 Leadership in MedTech
    • 2022 Leadership Voting!
    • 2021 Winners
    • 2020 Winners
  • Women in Medtech