A project led by Birmingham University aims to improve quality of life for amputees through development of a novel functional electrical stimulation (FES) device.
The researchers hope to meet currently unmet needs of amputees through their new assistive technology, with potential benefits to include improved function, pain management and mitigated risk of complications.
“Annually, there are more than one million amputations worldwide as a result of vascular diseases, trauma and cancer,” said principal investigator Dr Ziyun Ding, from Birmingham’s Department of Mechanical Engineering.
“With the increasing rate of diabetes and the population ageing, the amputee population is expected to double by 2050. A major limb amputation inevitably impairs mobility. In addition, amputees may suffer from chronic pain and the loss of muscle mass, which altogether in turn will [further diminish] their mobility.”
Ding described the team’s approach to using FES — a device to deliver small amounts of electrical current to muscles, providing additional amounts of muscle excitations for fulfilling functional tasks — as ‘ground-breaking’.
It involves maintaining a computational musculoskeletal model of the body to predict an optimal solution for amputees, she explained, which could prescribe the values of unknowns such as which muscles to stimulate, the amount and the timing of stimulation in a functional task.
“Our bodies have a great deal of redundancy: there are many ways to accomplish a task we ask our muscles to do,” Ding said. “That is a good thing: if one or several muscles are amputated, others can pick up the slack by working harder than they were before with an amputation.
“With the improved understanding of our bodies, especially the improved understanding of the relationship between the amounts we excite our muscles and the resulting motions of our bodies, we believe that we could help amputees regain their mobility.
“Simply speaking, if amputees could walk faster and longer with the assistance of prostheses as well as the functional electrical stimulation, this will be able to reduce other effects, typically pain and cardiovascular disease.”
Ding added that the team’s approach to modelling the human musculoskeletal system involves: model preparation for measuring movement and imaging data from patients; model construction to calibrate and estimate model parameters and incorporate clinical treatment plans in the model; and model utilisation to collect post-treatment movement and imaging data from patients and validate the model.
“Few labs throughout the world have reached the point of being able to apply such an approach to solve a mobility-related clinical problem,” she said. “The advances made through the research project could quickly improve the amputee healthcare provision in approximately three years’ time.”
The project will be delivered in partnership with Rice University in the US and involves collaboration with physiotherapists, amputee consultants and FES consultants from the West Midlands Rehabilitation Centre in Birmingham.