The seat of the problem

AITHM ergonomist, Associate Professor Gunther Paul, is at the forefront of developing customised wheel chair seating designed to reduce patient risk of pressure ulcers, an escalating burden on healthcare systems around the world.

“Pressure ulcers are not just debilitating and extremely painful, they are potentially lethal. The prevalence of this condition is increasing and the average cost of treating a patient is around $180,000,” said Dr Paul, a former leading edge car seat designer, who now works as a Principal Research Fellow in Occupational Health and Safety.

In 2017, he embarked on a joint project with Queensland Health’s Rehabilitation Engineering Centre, based at the Royal Brisbane Hospital, to explore how science and technology could efficiently deliver effective seating cushion solutions for patients, who often wait months for a finished product, under the current “trial and error” approach to customised seating modifications.

Dr Paul and his co-researchers set about taking the guess work out of seating design by developing a simulation process that accurately identifies how an individual human body in a seated posture interacts with varying forms and compositions of foam cushion material.

The first step was to construct a rigid, aluminium “indenter” device equipped with a three-dimensional (3-D) force gauge to measure the reaction force of the foam under pressure. It can be programmed to indent the foam for a specific period, or until a particular force or depth is reached.

The second challenge was to create 3-D printed shell replicas of individual human pelvises, to attach to the “indenter” during trials. Unlike conventional rigid shells, it was essential Dr Paul’s shells replicated human soft tissue, in order to accurately measure how a real body indented, while seated.

“We needed to conduct MRIs of people in a seated posture, in order to identify human tissue properties in that position and find a composite material that replicates it,” he said. “When we began, the only MRI capable of measuring seated people was in Aberdeen, Scotland. Thankfully, that has changed, so it is now possible to study a larger number of subjects.”

Dr Paul has successfully translated the current physical trial into a virtual test on a computer, which opens the door to even faster results for patients in sore need of rapid assistance.

“If we can simulate the same conditions in a computer model, then we can reduce the time that is required for an optimum cushion design, from currently around a year to possibly one week,” he said.

To date, the research trials have utilised MRI scans of healthy human subjects. He now plans to scan people with pressure ulcers to develop patient-specific seating solutions – which would be a world first.

The next step is commercialisation of the design process, which ideally would automate and further speed production, enabling those in wheel chairs to readily access appropriate seating in time to ward off the threat of pressure ulcers.

“Prevention is the big goal,” Dr Paul said. “We would love to take it to the point where we can serve patients, before they start suffering pressure ulcers.” 

 A/Prof Gunther Paul

Principal Research Fellow, Occupational Health and Safety

Australian Institute of Tropical Health & Medicine 

Anton Breinl Research Centre for Health Systems Strengthening

Email: gunther.paul@jcu.edu.au

Location: Mackay Campus