Transforming assistive technologies for people with movement disorders

A research collaboration between UTS Rapido and Northcott Innovation has produced a novel wheelchair toggle for people with severe involuntary tremors.

Severe traumatic brain injury (TBI) affects an estimated 5.48 million people globally yearly. These types of injuries can result in a range of movement disorders such as tremors (involuntary movement), paresis (muscle weakness), spasticity (abnormal muscle stiffness or tightness), apraxia (difficulty with skilled movement), or ataxia (impaired coordination).

In Sydney, a wheelchair user named Kyle inspired a novel research collaboration to support TBI patients with uncontrolled tremors to live more mobile and independent lives. Kyle acquired a brain injury that results in significant involuntary movements in her limbs, leading to frequent accidents caused by inadvertent pressure being applied to the wheelchair’s joystick controller.

In response, a research team at the advanced technology development unit UTS Rapido, supported by a UTS Social Impact Grant, have developed a novel wheelchair control toggle that can safely respond to uncontrolled tremors. The work came about through a longstanding partnership between UTS and Northcott Innovation, the ‘ideas factory’ of disability service provider Northcott.

“Samantha Frain, the Executive Director of Northcott Innovation, reached out to me a while ago and said, ‘We’ve got this client, we’ve tried everything that’s available on the market and nothing solves the problem’,” says Dr Michael Behrens, who leads commercial mechanical and mechatronic engineering projects at UTS Rapido.

“At the time, the Social Impact Grants were open for application, and I said, ‘Hey, we can apply for some funding and then we can actually get some engineering to look at this’.”

Area of expertise
Engineering

UTS Social Impact Framework Domain
Domain 4. Contributing to community

Sustainable Development Goal
Good health and wellbeing

Wicked problems, technological solutions

The Social Impact Grant provided $5,000 in funding, later matched by the UTS Faculty of Engineering and IT. Dr Behrens and final year Bachelor of Engineering (Mechanical and Mechatronic) student Chloe Mallinson then set out to deliver a novel solution.

The researchers met with Ms Frain and Kyle at Northcott in Parramatta to determine the project's scope. They collected real-life tremor data, measuring the torque of Kyle’s input motions to determine the pressure they placed on the wheelchair’s navigation joystick.

The measurements were significant, confirming what Kyle and the Northcott team already knew: tremors were routinely causing the wheelchair to careen through glass doors and into walls and other hazards, putting Kyle at substantial risk.

At first, Dr Behrens said, the problem seemed intractable, but he and Chloe were undeterred. Together, they devised a magnet-based toggle that could break the joystick away from the wheelchair when excessive force was applied.

We played around with a couple of different configurations to see which type of magnet would provide enough strength for the use of the wheelchair but be able to break during a significant tremor. Once we found a combination that worked, we looked at two different types of joysticks, a taller joystick and a shorter one, and we found that the shorter one worked better on the wheelchair. – Chloe Mallinson

When the toggle breaks away, the chair stops moving. Once the tremor has passed, the toggle can be clicked back into place, a task that Northcott staff have been working on with Kyle to ensure she can use the device independently.

It’s a deceptively simple solution, but the results have been immediate: since the toggle was installed six weeks ago, Kyle has gone from having multiple significant accidents a week, many forceful enough to break her wheelchair, to having none.

“Michael and Chloe’s work has meant that Kyle is maintaining her independence and quality of life,” says Ms Frain.

This remarkable outcome is a testament to the longstanding partnership between UTS Rapido and Northcott and the partners’ shared belief in innovation as a tool for social good.

“I think we are two like-minded organisations committed to bettering our general community,” Ms Frain says.

“We are both keen to give things a bit of a crack and understand that in design processes, things won’t always be a success, but it’s the commitment to keep trying, tweaking, thinking and not easily giving up that can truly make a difference.”

Solutions for any – and every – body

While the toggle was designed with Kyle in mind, the research holds potential for any wheelchair user living with movement disorders that manifest in a similar way. In addition to TBIs, people with Parkinson’s (10 million globally, 70 per cent with tremors ) and dyskinetic or athetoid type cerebral palsy (which can result in uncontrolled muscle movement) may also experience significant tremors that threaten their safety and independence.

The project was delivered via Rapido Social, a UTS Rapido program that delivers technology fixes for social impact. In that spirit, Dr Behrens and Mallinson, in partnership with Northcott Innovation, have started exploring options to commercialise the toggle, with one important caveat:

“We’re not trying to protect the intellectual property for this,” Dr Behrens says.

“We’ll release it into the wild, and if a wheelchair manufacturer wants to make it a standard part of their chair, we’ll all cheer and claim the credit and call that a win.”