Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New ‘bionic’ leg gives amputees a natural gait

18.08.2011
A new lower-limb prosthetic developed at Vanderbilt University allows amputees to walk without the leg-dragging gait characteristic of conventional artificial legs.

The device uses the latest advances in computer, sensor, electric motor and battery technology to give it bionic capabilities: It is the first prosthetic with powered knee and ankle joints that operate in unison.

It comes equipped with sensors that monitor its user’s motion. It has microprocessors programmed to use this data to predict what the person is trying to do and operate the device in ways that facilitate these movements.

“When its working, it’s totally different from my current prosthetic,” said Craig Hutto, the 23-year-old amputee who has been testing the leg for several years. “A passive leg is always a step behind me. The Vanderbilt leg is only a split-second behind.”

The bionic leg is the result of a seven-year research effort at the Vanderbilt Center for Intelligent Mechatronics, directed by Michael Goldfarb, the H. Fort Flowers Professor of Mechanical Engineering. The project was initially funded by a seed grant from the National Science Foundation, followed by a development grant from the National Institutes ofHealth. Key aspects of the design have been patented by the university, which has granted exclusive rights to develop the prosthesis to Freedom Innovations, a leading developer and manufacturer of lower limb prosthetic devices.

“With out latest model, we have validated our hypothesis that the right technology was available to make a lower-limb prosthetic with powered knee and ankle joints,” said Goldfarb. “Our device illustrates the progress we are making at integrating man and machine.”

The Vanderbilt prosthesis is designed for daily life. It makes it substantially easier for an amputee to walk, sit, stand, and go up and down stairs and ramps. Studies have shown that users equipped with the device naturally walk 25 percent faster on level surfaces than when they use passive lower-limb prosthetics. That is because it takes users 30 to 40 percent less of their own energy to operate.

“Going up and down slopes is one of the hardest things to do with a conventional leg,” said Hutto. “So I have to be conscious of where I go because I can get very tired walking up an down slopes. But that won’t be a problem with the powered leg because it goes up and down slopes almost like a natural leg.”

Recent technological advances have allowed the Vanderbilt engineers to produce a device that weighs about nine pounds – less than most human lower legs – and can operate for three days of normal activity, or 13 to 14 kilometers of continuous walking, on a single charge. They have also dramatically reduced the amount of noise that the latest model makes, although it is slightly louder than they would like.

One of the latest capabilities that the engineers have added is an anti-stumble routine. If the leg senses that its user is starting to stumble, it will lift up the leg to clear any obstruction and plant the foot on the floor.

In order to incorporate all the improvements, the prosthetic’s hardware design has gone through seven versions and its electronics board has been redone 15 times.

According to Goldfarb, it was tough to make the prosthetic light and quiet enough. In particular, it was difficult to fit the powerful motors and drive train that they needed into the volume available. The biggest technical challenge, however, was to develop the control system.

“As you add greater capability, you are also adding greater liability,” he said. “Not only does the controller have to perform individual operations reliability, but it has to perform several operations at the same time and not get confused.”

The Center for Intelligent Mechatronics is also developing an anthropomorphic prosthetic arm project and an advanced exoskeleton to aid in physical therapy.

Visit Research News @ Vanderbilt for more research news from Vanderbilt.

David F. Salisbury | Vanderbilt University
Further information:
http://www.vanderbilt.edu

More articles from Health and Medicine:

nachricht New 3-D imaging reveals how human cell nucleus organizes DNA and chromatin of its genome
28.07.2017 | University of California - San Diego

nachricht Malaria Already Endemic in the Mediterranean by the Roman Period
27.07.2017 | Universität Zürich

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Abrupt motion sharpens x-ray pulses

Spectrally narrow x-ray pulses may be “sharpened” by purely mechanical means. This sounds surprisingly, but a team of theoretical and experimental physicists developed and realized such a method. It is based on fast motions, precisely synchronized with the pulses, of a target interacting with the x-ray light. Thereby, photons are redistributed within the x-ray pulse to the desired spectral region.

A team of theoretical physicists from the MPI for Nuclear Physics (MPIK) in Heidelberg has developed a novel method to intensify the spectrally broad x-ray...

Im Focus: Physicists Design Ultrafocused Pulses

Physicists working with researcher Oriol Romero-Isart devised a new simple scheme to theoretically generate arbitrarily short and focused electromagnetic fields. This new tool could be used for precise sensing and in microscopy.

Microwaves, heat radiation, light and X-radiation are examples for electromagnetic waves. Many applications require to focus the electromagnetic fields to...

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

New 3-D imaging reveals how human cell nucleus organizes DNA and chromatin of its genome

28.07.2017 | Health and Medicine

Heavy metals in water meet their match

28.07.2017 | Power and Electrical Engineering

Oestrogen regulates pathological changes of bones via bone lining cells

28.07.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>