A helping arm for recovering stroke patients
A machine co-developed by a TCD professor could help patients regain upper limb movement after a stroke, writes TIM O'BRIEN
A machine which can significantly enhance recovery of upper limb movement in people who have had a severe stroke or brain injury has been developed by a Trinity College Dublin professor and a team of Australian researchers.
Clinical trials of the Sensory-Motor Active Rehabilitation Training (Smart) Arm have shown patients who had little or no upper limb movement for up to three and a half years after a stroke increased the distance they could reach by 11 centimetres on average. This followed only four weeks of training.
Prof Richard Carson, chair in cognitive neuroscience of ageing at TCD, and researchers based in the University of Queensland have signed a deal with an Australian healthcare company to produce an initial 3,500 of the machines.
Prof Carson says almost eight years of research and clinical trials went into developing the machine, which works by electrically stimulating movement in the patient’s arm. He hopes it will be produced in such numbers to be affordable to nursing homes, community centres and even private homes.
The portable technology works by generating electrical impulses which assist the human function in the limbs. According to Prof Carson, the trials showed the machine to be particularly useful in cases where the limb was too weak to participate in normal task-oriented training because the patient had insufficient underlying movement to begin with.
“Not enough movement to work with” is traditionally the greatest barrier to patient recovery, he says. “This may explain why those with severe paresis show little improvement and so are increasingly excluded from active rehabilitation.”
While robotic exercise machines have been found to reduce arm impairment in stroke survivors with severe paresis, such machines are typically large and expensive and located in a hospital. Patients tend to have access limited to a couple of visits a week.
“Clearly, there was a pressing need to develop economical, non-robotic devices to aid the stroke survivor with severe paresis,” says Prof Carson.
The Smart Arm was designed to first reduce task difficulty by providing a mechanical guide and by minimising resistance to movement. This means that the patient’s effort can be concentrated on reaching forward.
In trials, provision was made for increments in load to promote increases in muscle strength, and the primary aim of the device was to enable the stroke survivor with severe paresis to actively participate in intensive and repetitive task-oriented practice, where previously this had not been possible.
Clinical trials reported by Prof Carson and his colleagues Ruth Barker and Sandra Brauer found that training using the Smart Arm reduced impairment and improved activity in stroke survivors with severe and chronic upper limb paresis.
Prof Carson wants the new device to be low enough in cost so as to enable the stroke survivor “to actively participate” in intensive and repetitive task-oriented practice, where previously this had not been possible due to time constraints and scheduling of hospital visits, waiting lists, costs and other issues.
Among the chief benefits of the device, he says, is that in mass production it could be low-cost enough to allow patients to use it intensively either at home or in the nursing home.
Under the deal with Australian healthcare provider Townsville-Mackay Medicare Local, a new company, Smart Arm Pty Ltd, has been established with the aim of manufacturing some 3,500 of the machines for distribution in mid-2013 to nursing homes and other medical facilities in Australia.
Stroke is the leading cause of severe long-term disability in the Western world, says Prof Carson. “Every year, more than three million stroke survivors try to regain use of their upper limbs, and so we’re very keen to see the device become available to as many as possible, as soon as possible.”
Dr Kevin Arlett, chairman of Townsville-Mackay Medicare Local, says the company recognises the potential for Smart Arm to address a major unmet need in the allied health care industry.
“The Smart Arm will make a huge difference to stroke survivor outcomes because it’s interactive and it allows patients to practise independently and direct their own rehabilitation.
“And, because it’s small enough to be used for clinical inpatient and outpatient settings as well as in rehabilitation services, nursing homes and local area health services, more people will benefit.”