Video by Bryan Nakata.
“For those of us living with spinal cord injuries, there are many activities that require the type of grip the orthosis provides or improves. Pulling your pants up, holding a pencil, picking items up, holding a hairbrush or toothbrush, holding a drinking glass, using eating utensils. The list is endless. Imagine having to have a special adaption on each item you use, or worse yet, to have someone to do these things for you just because your hand won’t grip or has no strength.”
—Bonnie, design partner
Currently, about 276,000 people in the U.S. are living with spinal cord injuries affecting the C5-C7 vertebrae. These injuries are not congenital; they are the life-altering result of accidents — 47% which result in tetraplegia, the paralysis of all four limbs. Of those affected, approximately 75% would prefer to regain the use of their hands over any other function, including the ability to walk. Limited use of their hands makes day-to-day activities like eating or brushing their teeth difficult to accomplish. Levinson Scholar Sasha Portnova’s work sought to make routine tasks more manageable for this population.
As a University of Washington undergraduate, Sasha (’16) worked in the Ability and Innovation Lab to make an improved version of the standard wrist-assist device. This device is a prosthetic tool used to help an individual move their hand enough to accomplish daily tasks. The base requirement to use this tool is the ability to flex and extend one’s wrist against gravity. The downward motion of the wrist then activates the device to move the user’s fingers. This helps them hold objects, such as toothbrushes and forks.
Traditionally, these devices are made from metal and labor-intensive to assemble. While materials only cost $150, it can sometimes take clinicians 15-20 hours to assemble, making it too expensive for many potential users. On top of that, the prosthetists and orthoptists Sasha interviewed explained the metal models were their least favorite device to assemble due to the laborious construction and fact that users found the devices cumbersome and often rejected them.
Sasha’s version is made of plastic and the parts are printed on a 3D printer. Measurements are taken before the device is printed and the physician can pre-select the size, streamlining the fitting process. Materials cost approximately $15 and assembly takes about 1.5 hours. What’s more, it’s 68% lighter than the metal version and it looks better. Users can even choose the color.
Wrist-assist device users as co-designers
“I am always eager to help improve the lives for those with spinal cord injuries, including myself. Any advancement in useful technology is a step in the right direction. I believe awareness and technology are the keys to a future without physical limitations due to disability. To be a part of this gives me meaningful purpose.”
—Bonnie, design partner
Sasha used an iterative, human-centered design approach to revise the device. She interviewed people who had previously tried the standard device. They explained it was bulky, uncomfortable, heavy, and they ultimately stopped wearing it. She listened to the users’ suggestions for improvements and used her engineering background to make revisions. The users came in to test the revisions; Sasha would make further modifications to the design and fit. Once both were satisfied, the user left with a new wrist-assist device.
“The feedback we got from the users was very positive. They reported that this device was much lighter, easier to use and more aesthetically pleasing than the traditional model. Several users commented that using this device earlier in their recovery would have helped immensely.”
—Sasha
Sharing her research in Washington D.C. and beyond
Sasha used her Levinson award to travel to conferences and present her findings to larger audiences. “Through these conferences, l learned to share my research with the broader science community. Initially, I was nervous about presenting my research to my peers. But, then I realized no one knows your project better than you do. I am now very comfortable talking about my research.”
Conference highlights include giving her first podium presentation at the American Academy of Orthoptists and Prosthetists in Orlando, Florida, and attending Posters on the Hill in Washington, D.C. There, she met with Washington state senators Maria Cantwell and Patty Murray, as well as Congressman Dan Newhouse to explain the importance of undergraduate research and inspire them to continue to fund undergraduate research. Sasha credits these experiences with introducing her to the larger world of academia and starting to establish herself in the field.
“This project got me excited about research and is the reason I am continuing with a Ph.D. I love asking a medical question and answering it with engineering tools.”
Sasha graduated in spring 2016. Her undergraduate research experience inspired her to pursue a Ph.D. in mechanical engineering at Northwestern University. Her work will focus in robotics and motor control. She is currently working on a project at the Research Institute of Chicago. Even though she’s graduated, she continues to promote the wrist-assist device. Rather than maximizing profit, Sasha wants this to be open source to help the maximum number of people in the world.
Conference List
Society of Women Engineers – Seattle, WA
Posters on the Hill – Washington, D.C.
American Academy of Orthoptists and Prosthetists – Orlando, Florida
Northwest Biomechanics Symposium in Canada
American Society in Biomechanics – Raleigh, NC
University of Washington’s Undergraduate Research Symposium – Seattle, WA