|
Volume 16, No. 4 • Fall 2008 |
Subscribe to AT Messenger Download PDF Viewer |
| PDF Version (for printing) Large Print (PDF) Text Version |
Dave Pedicone
Nemours Biomedical Research
Research Assistant
Alfred I. duPont Hospital for Children
Tariq Rahman
Nemours Biomedical Research
Senior Research Engineer
Alfred I. duPont Hospital for Children
Imagine a person unable to move his/her arm because the arm is too heavy. If only there was a way to remove gravity from the equation! Well that may be a tall order, but what if there were a device that would make it ‘feel’ as if the arm weighed nothing? Maybe this would level the playing field for children eager to explore their environment and do the things other children do with little effort. Many people with weak muscles have trouble performing the simplest of functions such as scratching their nose or bringing a slice of pizza to their mouth. They often use awkward compensatory movements to get the job done, or have to ask someone else to do things for them. This need for assistance can affect their dignity, self-esteem, and quality of life. The upper extremity exoskeleton attempts to address some of these movement-related issues. What is an upper extremity exoskeleton? Read on, and you will learn more.
At Nemours/Alfred I. duPont Hospital for Children, the Pediatric Engineering Research Laboratory (PERL), in collaboration with clinical departments in the hospital, has developed a mechanical arm exoskeleton that can be ‘worn’ by a child. This device, called the WREX (Wilmington Robotic Exoskeleton), is powered by elastic bands allowing children to ‘float’ their hand in front of them. The WREX can be attached to either a wheelchair or to a back brace for patients who are able to walk. WREX is prescribed for children and adults with conditions that cause upper extremity weakness such as muscular dystrophy, spinal muscular atrophy, and spinal cord injury. Funding for this project was provided by Nemours Biomedical Research, the National Institutes of Health, and the Department of Education. WREX has been patented by Nemours and is sold commercially by JAECO Orthopedics (http://jaeco-orthopedic.com/).
The PERL lab has had vital input from some of its users through several stages of the WREX development process. Often times assistive technology development relies on patients providing valuable insight into the development of the new technology. This has been the case with Matthew. Matthew was 10 when first fitted with the WREX. He has had the WREX for 4 years now and wears it all the time. He relies on it for feeding himself at mealtime and for a host of other tasks. Matthew’s feedback has been critical in the development of the WREX. He continues to provide us with feedback as we constantly improve the WREX. Additional upgrades include assisted wrist rotation and smoother joint bearings.
The PERL lab is continuing to work with JAECO Orthopedics to develop the next generation WREX. The new model will use “new generation” elastics and be more streamlined while including electric motors for patients with profound weakness. Powered by batteries and enabling the lifting of heavier objects, the motors will be controlled by sensors that measure muscle force and electrical signals. These signals are called electromyographic signals, or EMG, and are activated when muscles are contracted. Using appropriate sensors, these small electrical signals can be detected and used to control an electric motor. The new generation WREX continues to be a main area of investigation in the PERL laboratory.
To learn more about the Center for Orthopedic Research & Development, the Pediatric Engineering Research Lab, please visit: http://www.nemours.org/research/biomedical/center/cord.html.
