Experiment adds sense of touch to artificial hand

Feb 5 2014, 2:06pm CST | by

HEALTHBEAT: Scientists add sense of touch to robotic hand, a step to more lifelike prosthetics

WASHINGTON (AP) — To feel what you touch — that's the holy grail for artificial limbs. In a step toward that goal, European researchers created a robotic hand that let an amputee feel differences between a bottle, a baseball and a mandarin orange.

The patient only got to experiment with the bulky prototype for a week, and it's far from the bionics of science fiction movies. But the research released Wednesday is part of a major effort to create more lifelike, and usable, prosthetics.

"It was just amazing," said Dennis Aabo Sorensen of Aalborg, Denmark, who lost his left hand in a fireworks accident a decade ago and volunteered to pilot-test the new prosthetic. "It was the closest I have had to feeling like a normal hand."

This isn't the first time scientists have tried to give some sense of touch to artificial hands; a few other pilot projects have been reported in the U.S. and Europe. But this newest experiment, published in the journal Science Translational Medicine, shows Sorensen not only could tell differences in the shape and hardness of objects, he also could quickly react and adjust his grasp.

"It was interesting to see how fast he was able to master this," said neuroengineer Silvestro Micera of Switzerland's Ecole Polytechnique Federale de Lausanne, who led the Swiss and Italian research team. "He was able to use this information immediately in a quite sophisticated way."

Scientists have made great strides in recent years in improving the dexterity of prosthetics. But the sense of touch has been a much more difficult challenge, and is one reason that many patients don't use their prosthetic hands as much as they'd like.

Consider: Grab something and your own hand naturally grasps with just enough force to hang on. Users of prosthetic hands have to carefully watch every motion, judging by eye instead of touch how tightly to squeeze. The results can be clumsy, with dropped dishes or crushed objects.

"You always have to look and see what's going on, so that's what is so much different from this new hand that I tried," Sorensen, 36, said in a telephone interview.

First, doctors at Rome's Gemelli Hospital implanted tiny electrodes inside two nerves — the ulnar and median nerves — in the stump of Sorensen's arm.

Those nerves normally would allow for certain sensations in a hand. When researchers zapped them with a weak electrical signal, Sorensen said it felt like his missing fingers were moving, showing the nerves still could relay information.

Meanwhile, Micera's team put sensors on two fingers of a robotic hand, to detect information about what the artificial fingers touched.

For one week, cords snaked from a bandage on Sorensen's arm to the artificial hand, and the electrodes zapped the nerves in proportion to what the sensors detected.

They essentially created a loop that let the robotic hand rapidly communicate with Sorensen's brain.

"It is really putting the brain back in control of the system," said biomedical engineer Dustin Tyler of Case Western Reserve University, who wasn't involved with the European work but leads a team in Ohio that recently created and tested a similar touch-enabled hand. "That's an important step."

Added neurobiologist Andrew Schwartz of the University of Pittsburgh: "It shows with a few sensors and some pretty elementary technology, that they can recover a fair amount of functionality."

To be sure Sorensen used touch, and didn't cheat by looking or hearing telltale sounds, he wore a blindfold and headphones as Micera's team handed him different objects.

"Suddenly I could tell if it was a hard object," Sorensen recalled, describing sensations that changed along with his grip. "The response, the feedback from the arm to my nerves and to my brain, they came very strong."

Micera cautioned that it will take several years of additional research to create a first-generation artificial hand that can feel, and looks more like a traditional prosthetic. First, they have to prove these nerve implants can last; for safety reasons, Sorensen's were surgically removed after the experiment.

But a lot of work is under way.

In Ohio, Tyler's team recently issued video showing a blindfolded man gently pulling stems from cherries without crushing them, thanks to similar implanted nerve stimulators and a sensor-equipped prosthetic hand. The main difference, said Switzerland's Micera, is in how the nerve electrodes are implanted. The European approach puts them inside the nerve rather than around it for better control, but that's more invasive and some researchers worry it could damage the nerve over time.

In Pittsburgh, Schwartz's team is about to test another approach — a brain-controlled robotic hand for the paralyzed that would "feel" through electrodes implanted in a brain region known as the sensory cortex.

Whatever the approach, touch is a complex sense and these are all basic first steps involving how someone grasps, not more sophisticated sensations such as texture or temperature.

"There is definitely tremendous value to having a sense of touch, a sense of feeling from the hand," said Case Western's Tyler. "What that feeling is, how we use it — that's yet to come."

Source: AP Business

 
 

Don't miss ...

 

<a href="/latest_stories/all/all/31" rel="author">Associated Press</a>
The Associated Press (AP) is one of the largest and most trusted sources of independent newsgathering, supplying a steady stream of news to its members, international subscribers and commercial customers.

 

blog comments powered by Disqus

Latest stories

Carla Bruni to lend voice to combat Ebola
Paris, Nov 22 (IANS/EFE) Former model and former first lady of France, Carla Bruni, will lend her voice to the French version of the song "Do They Know It's Christmas?" to raise funds to help combat Ebola.
 
 
Spanish health worker flown home after possible Ebola contagion
Madrid, Nov 21 (IANS) A Spanish health worker with Doctors Without Borders (MSF) arrived back in Spain Friday morning from Mali after being deemed at risk of contagion from the Ebola virus.
 
 
Japanese government concerned by yen's rapid fall against dollar
Tokyo, Nov 21 (IANS/EFE) Japanese Finance Minister Taro Aso Friday expressed concern over the sharp depreciation of the yen against the dollar this week, and said abrupt movements in the foreign exchange market were not beneficial to the Japanese economy.
 
 
WHO declares DRC Ebola-free
Geneva, Nov 21 (IANS) The World Health Organisation (WHO) Friday declared the end of the Ebola outbreak in the Democratic Republic of Congo (DRC).
 
 
 

Latest from the Network

Kris Jenner keen on Kourtney and Khloe double wedding
Kris Jenner wants Kourtney and Khloé Kardashian to have a double wedding. The 59-year-old manager reportedly thinks Kourtney should marry Scott Disick and Khloé should marry French Montana during the same ceremony for...
Read more on Celebrity Balla
 
Miley Cyrus and Patrick Schwarzenegger planning holiday
Miley Cyrus and Patrick Schwarzenegger are planning to go on a romantic holiday. The 'Wrecking Ball' hitmaker is said to be smitten with the 21-year-old hunk - the son of Hollywood legend Arnold Schwarzenegger and Maria...
Read more on Celebrity Balla
 
Kelly Brook's Winter Chunderland
Kelly Brook was nearly sick at London's Winter Wonderland attraction yesterday (20.11.14). The 34-year-old model attended the VIP launch of the annual festive fair in Hyde Park, and admitted to feeling worse for wear...
Read more on Celebrity Balla
 
Katy Perry and will.i.am to cover Imagine for UNICEF
Yoko Ono, Katy Perry, will.i.am and David Guetta are among the celebrities who have recorded a cover of John Lennon's 'Imagine' to raise funds for UNICEF. The star-studded cover will be accompanied by an interactive...
Read more on Celebrity Balla
 
Spanish health worker flown home after possible Ebola contagion
Madrid, Nov 21 (IANS) A Spanish health worker with Doctors Without Borders (MSF) arrived back in Spain Friday morning from Mali after being deemed at risk of contagion from the Ebola virus. MSF confirmed the female...
Read more on Business Balla
 
Ukraine accuses Russia of cross-border shelling (Roundup)
Kiev, Nov 21 (IANS) Ukraine Friday accused Russia of carrying out cross-border shelling against Ukrainian positions in the eastern part of the country even as pro-Russian separatists put the toll in the ongoing...
Read more on Politics Balla
 
Obama set to be chief guest at India's R-Day (Lead, changing dateline)
Washington, Nov 21 (IANS) Signifying a renewal of the India-US strategic partnership, President Barack Obama has accepted Prime Minister Narendra Modi's invitation to join India's Republic Day celebrations as chief...
Read more on Politics Balla
 
Chinese court upholds life sentence against Uyghur activist
Beijing, Nov 21 (IANS/EFE) A court in western China has upheld the conviction and life sentence handed down against Uyghur activist Ilham Tohti, who appealed the sentence when it was first passed in September, one of...
Read more on Politics Balla
 
Matt Smith to star in Patient Zero
Matt Smith has been cast in 'Patient Zero'. The former 'Doctor Who' star has signed on to appear in the infection film which will see him have to cope with the aftermath of a worldwide viral pandemic across the Earth....
Read more on Movie Balla
 
Mick Jagger praises 'amazing' Chadwick Boseman
Sir Mick Jagger claims Chadwick Boseman is ''amazing'' as James Brown in the singer's biopic 'Get On Up'. The 71-year-old Rolling Stones rocker co-produced the movie and praised the young actor for his portrayal of the...
Read more on Movie Balla