Featured Research

from universities, journals, and other organizations

Smartphone technology improves prosthetic limbs

Date:
December 14, 2010
Source:
The Norwegian University of Science and Technology (NTNU)
Summary:
By combining smartphone technology with artificial limbs, researchers are paving the way for a new generation of prostheses. The technology, called an accelerometer, gives users a better sense of the orientation of their artificial limb – thus making the limb easier to operate.

Losing a limb can be a devastating experience, and while electrically powered prostheses can serve as a replacement for a lost arm, they are notoriously difficult to operate, and will never fully replace normal hand function. Researchers at the Norwegian University of Science and Technology (NTNU) are working to improve this situation through the use of smartphone technology. The technology, called an accelerometer, gives users a better sense of the orientation of their artificial limb -- thus making the limb easier to operate.

A helping hand

An accelerometer is a tool for detecting changes in gravity or velocity, and enables a device to determine its orientation. Accelerometers are relatively inexpensive, and are widely used in everything from video consoles to smartphones. The accelerometer in your smartphone helps it determine whether you want to look at a photograph in a portrait or landscape format, for example.

Ψyvind Stavdahl, an associate professor at NTNU's Department of Engineering Cybernetics and Anders Fougner, a PhD candidate in the department, have shown that when an accelerometer is used in a prosthetic arm, it is easier for the user to recognize exactly how the arm is oriented in space.

"Prostheses are driven by the remaining muscles in the severed limb. Sometimes, however, the prosthesis receives atypical signals from the muscles, which can confuse the system and lead to the prosthesis performing the wrong movement," Stavdahl says. "Knowing the orientation of the arm is essential for normal prosthetic function. It simply makes it a lot easier to operate."

Problems at Home

Since the first electrically powered prostheses appeared in the 1940s, there have been huge technological advancements in the field. Despite this, modern upper limb prostheses share the same basic structure as their 1940s forbears, with a mechanical hand that can grasp. Sometimes the arm includes a rotating wrist.

An amputee operates his or her prosthesis by moving a muscle, which then sends out a kind of electrical signal. Electrodes placed on the surface of the skin detect these "myoelectric" signals and convert them to movement using a microprocessor and motor. Activating specific groups of muscles will lead to specific movements, such as opening or closing the hand, or rotating the wrist.

"Mastering these hand movements require a lot of practice," says Fougner. In fact, Stavdahl and Fougner's research has shown that without any training, the user's prosthesis will make the wrong move around 30 per cent of the time.

Hence, amputees are usually offered extensive training in a clinical setting, but when they return home, they start running into problems.

"A simple task, like picking up a cup of tea, might prove difficult," says Stavdahl. "If you try to do this when the arm is in an awkward position, that is, a position that you haven't practiced with before, the muscles will start sending unfamiliar signals to the prosthesis. This will often lead to the prosthesis doing the opposite of what the user intended -- and the cup will fall to the ground."

An accelerometer helps to compensate for these unfamiliar signals, reducing the user's frustration.

Commercial potential

Prosthetic limbs can be tricky to manoeuvre. Younger people generally learn quicker, but some give up, and never manage to use the full potential of the device.

"Our hope is that this application might improve the lives of people," says Fougner. But he stresses that it is equally important for prosthetic users to be given adequate training. Their research has shown that an accelerometer, combined with proper training, reduces the frequency of incorrect movements from 30 to 5 percent.

Although this is a niche market in Norway, where there are only about 600 upper limb prosthetic users, the new approach has huge commercial potential worldwide, particularly in Asia and the Middle East. "A more functional prosthesis might be on the market in a couple of years," says Stavdahl.

The research is being conducted in collaboration with researchers at the University of New Brunswick in Canada.


Story Source:

The above story is based on materials provided by The Norwegian University of Science and Technology (NTNU). Note: Materials may be edited for content and length.


Journal Reference:

  1. Chun-Xiao Song, Keith E Szulwach, Ye Fu, Qing Dai, Chengqi Yi, Xuekun Li, Yujing Li, Chih-Hsin Chen, Wen Zhang, Xing Jian, Jing Wang, Li Zhang, Timothy J Looney, Baichen Zhang, Lucy A Godley, Leslie M Hicks, Bruce T Lahn, Peng Jin, Chuan He. Selective chemical labeling reveals the genome-wide distribution of 5-hydroxymethylcytosine. Nature Biotechnology, 2010; DOI: 10.1038/nbt.1732

Cite This Page:

The Norwegian University of Science and Technology (NTNU). "Smartphone technology improves prosthetic limbs." ScienceDaily. ScienceDaily, 14 December 2010. <www.sciencedaily.com/releases/2010/12/101213071108.htm>.
The Norwegian University of Science and Technology (NTNU). (2010, December 14). Smartphone technology improves prosthetic limbs. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2010/12/101213071108.htm
The Norwegian University of Science and Technology (NTNU). "Smartphone technology improves prosthetic limbs." ScienceDaily. www.sciencedaily.com/releases/2010/12/101213071108.htm (accessed September 2, 2014).

Share This




More Health & Medicine News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Snack Attack: Study Says Action Movies Make You Snack More

Snack Attack: Study Says Action Movies Make You Snack More

Newsy (Sep. 2, 2014) — You're more likely to gain weight while watching action flicks than you are watching other types of programming, says a new study published in JAMA. Video provided by Newsy
Powered by NewsLook.com
U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

Newsy (Sep. 2, 2014) — The U.N. says the problem is two-fold — quarantine zones and travel restrictions are limiting the movement of both people and food. Video provided by Newsy
Powered by NewsLook.com
Doctors Fear They're Losing Battle Against Ebola

Doctors Fear They're Losing Battle Against Ebola

AP (Sep. 2, 2014) — As a third American missionary is confirmed to have contracted Ebola in Liberia, doctors on the ground in West Africa fear they're losing the battle against the outbreak. (Sept. 2) Video provided by AP
Powered by NewsLook.com
Tech Giants Bet on 3D Headsets for Gaming, Healthcare

Tech Giants Bet on 3D Headsets for Gaming, Healthcare

AFP (Sep. 2, 2014) — When Facebook acquired the virtual reality hardware developer Oculus VR in March for $2 billion, CEO Mark Zuckerberg hailed the firm's technology as "a new communication platform." Duration: 02:24 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins