(September 28, 2015) When
amputees receive powered prosthetic legs, the power of the prosthetic limbs
needs to be tuned by a prosthetics expert so that a patient can move normally –
but the prosthetic often needs repeated re-tuning. Biomedical engineering
researchers at North Carolina State University and the University of North
Carolina at Chapel Hill have now developed software that allows powered
prosthetics to tune themselves automatically, making the devices more
functionally useful and lowering the costs associated with powered prosthetic
use.
“When a patient gets a powered prosthetic, it needs to be
customized to account for each individual patient’s physical condition, because
people are different in size and strength. And that tuning is done by a
prosthetist,” says Helen Huang, lead author of a paper on the work and an
associate professor in the biomedical engineering program at NC State and
UNC-Chapel Hill. “In addition, people are dynamic – a patient’s physical
condition may change as he or she becomes accustomed to a prosthetic leg, for
example, or they may gain weight. These changes mean the prosthetic needs to be
re-tuned, and working with a prosthetist takes time and money.”
To address this problem, the researchers developed an
algorithm that can be incorporated into the software of any powered prosthesis
to automatically tune the amount of power a prosthetic limb needs in order for
a patient to walk comfortably. The algorithm would not only make it easier for
patients to walk while reducing prosthetist-related costs, but would also allow
a prosthesis to adjust to changing conditions. Video of the technology in
action can be seen here.
“For example, the algorithm could provide more power to a
prosthesis when a patient carries a heavy suitcase through an airport,” Huang
says.