Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Prosthetic arms can provide controlled sensory feedback, study finds

27.04.2018

Losing an arm doesn't have to mean losing all sense of touch, thanks to prosthetic arms that stimulate nerves with mild electrical feedback.

University of Illinois researchers have developed a control algorithm that regulates the current so a prosthetics user feels steady sensation, even when the electrodes begin to peel off or when sweat builds up.


A patient performs various everyday tasks with a sensory control module integrated with his prosthetic arm.

Credit: Aadeel Akhtar, University of Illinois

"We're giving sensation back to someone who's lost their hand. The idea is that we no longer want the prosthetic hand to feel like a tool, we want it to feel like an extension of the body," said Aadeel Akhtar, an M.D./Ph.D. student in the neuroscience program and the medical scholars program at the University of Illinois. Akhtar is the lead author of a paper describing the sensory control module, published in Science Robotics, and the founder and CEO of PSYONIC, a startup company that develops low-cost bionic arms.

"Commercial prosthetics don't have good sensory feedback. This is a step toward getting reliable sensory feedback to users of prosthetics," he said.

Prosthetic arms that offer nerve stimulation have sensors in the fingertips, so that when the user comes in contact with something, an electrical signal on the skin corresponds to the amount of pressure the arm exerts. For example, a light touch would generate a light sensation, but a hard push would have a stronger signal.

However, there have been many problems with giving users reliable feedback, said aerospace engineering professor Timothy Bretl, the principal investigator of the study. During ordinary wear over time, the electrodes connected to the skin can begin to peel off, causing a buildup of electrical current on the area that remains attached, which can give the user painful shocks. Alternately, sweat can impede the connection between the electrode and the skin, so that the user feels less or even no feedback at all.

"A steady, reliable sensory experience could significantly improve a prosthetic user's quality of life," Bretl said.

The controller monitors the feedback the patient is experiencing and automatically adjusts the current level so that the user feels steady feedback, even when sweating or when the electrodes are 75 percent peeled off.

The researchers tested the controller on two patient volunteers. They performed a test where the electrodes were progressively peeled back and found that the control module reduced the electrical current so that the users reported steady feedback without shocks. They also had the patients perform a series of everyday tasks that could cause loss of sensation due to sweat: climbing stairs, hammering a nail into a board and running on an elliptical machine.

"What we found is that when we didn't use our controller, the users couldn't feel the sensation anymore by the end of the activity. However, when we had the control algorithm on, after the activity they said they could still feel the sensation just fine," Akhtar said.

Adding the controlled stimulation module would cost much less than the prosthetic itself, Akhtar said. "Although we don't know yet the exact breakdown of costs, our goal is to have it be completely covered by insurance at no out-of-pocket costs to users."

The group is working on miniaturizing the module that provides the electrical feedback, so that it fits inside a prosthetic arm rather than attaching to the outside. They also plan to do more extensive patient testing with a larger group of participants.

"Once we get a miniaturized stimulator, we plan on doing more patient testing where they can take it home for an extended period of time and we can evaluate how it feels as they perform activities of daily living. We want our users to be able to reliably feel and hold things as delicate as a child's hand," Akhtar said. "This is a step toward making a prosthetic hand that becomes an extension of the body rather than just being another tool."

###

The National Institutes of Health and the National Science Foundation supported this work.

Editor's notes: To reach Aadeel Akhtar, email aakhta3@illinois.edu. To reach Timothy Bretl, email tbretl@ilinois.edu.

The paper "Controlling sensation intensity for electrotactile stimulation in human-machine interfaces" is available online or from the News Bureau.

DOI: 10.1126/scirobotics.aap9770

Media Contact

Liz Ahlberg Touchstone
eahlberg@illinois.edu
217-244-1073

 @NewsAtIllinois

http://www.illinois.edu 

Liz Ahlberg Touchstone | EurekAlert!
Further information:
https://news.illinois.edu/view/6367/643862
http://dx.doi.org/10.1126/scirobotics.aap9770

More articles from Power and Electrical Engineering:

nachricht A spreadable interlayer could make solid state batteries more stable
19.05.2020 | Chalmers University of Technology

nachricht A new, highly sensitive chemical sensor uses protein nanowires
14.05.2020 | University of Massachusetts Amherst

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: When predictions of theoretical chemists become reality

Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.

Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...

Im Focus: Rolling into the deep

Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.

A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...

Im Focus: NASA's Curiosity rover finds clues to chilly ancient Mars buried in rocks

By studying the chemical elements on Mars today -- including carbon and oxygen -- scientists can work backwards to piece together the history of a planet that once had the conditions necessary to support life.

Weaving this story, element by element, from roughly 140 million miles (225 million kilometers) away is a painstaking process. But scientists aren't the type...

Im Focus: Making quantum 'waves' in ultrathin materials

Study co-led by Berkeley Lab reveals how wavelike plasmons could power up a new class of sensing and photochemical technologies at the nanoscale

Wavelike, collective oscillations of electrons known as "plasmons" are very important for determining the optical and electronic properties of metals.

Im Focus: When proteins work together, but travel alone

Proteins, the microscopic “workhorses” that perform all the functions essential to life, are team players: in order to do their job, they often need to assemble into precise structures called protein complexes. These complexes, however, can be dynamic and short-lived, with proteins coming together but disbanding soon after.

In a new paper published in PNAS, researchers from the Max Planck Institute for Dynamics and Self-Organization, the University of Oxford, and Sorbonne...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

 
Latest News

New gravitational-wave model can bring neutron stars into even sharper focus

22.05.2020 | Physics and Astronomy

A replaceable, more efficient filter for N95 masks

22.05.2020 | Materials Sciences

Capturing the coordinated dance between electrons and nuclei in a light-excited molecule

22.05.2020 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>