Ann Arbor, MI – Allowing exoskeleton users to set their own preferences not only speeds up the customization process, but can also lead to increased adoption and use of the technology, according to the results of a recent study.
Researchers at the University of Michigan asked 24 participants, half of whom had no experience working with exoskeletons, to wear a powered ankle exoskeleton while walking on a treadmill with a tablet displaying a blank grid. “Selecting any point on the grid would change the exoskeleton’s torque output on one axis, while changing the timing of that torque on the other axis,” the researchers said.
The participants tried to find their optimal parameters. Inexperienced participants were able to do this, on average, in 1 minute and 45 seconds.
“We were surprised at how accurately people were able to identify their preferences, especially since they were completely blinded to everything that was going on – we didn’t tell them what settings they were adjusting, so they only selected their preferences than how they felt the device was helping them,” lead researcher Kim Ingraham said in a press release.
Typically, experts choose exoskeleton parameters based on the user’s height and weight, among other characteristics, including gait biomechanics.
“This can be done by analyzing quantifiable data, such as metabolic rate or muscle activity, to minimize energy expended by a user, or more simply by asking the user to repeatedly compare between pairs of settings to find the one that feels best,” the statement states. “What minimizes energy expenditure, however, may not be the most comfortable or the most useful.”
The researchers then want to know why users have certain preferences and how those preferences affect their energy, muscle activity and physiology. Another area of future study will focus on how to implement automatic preference-based controls in the use of exoskeletons.
“Being able to choose and control how one feels is going to help drive user satisfaction and adoption of these devices in the future,” Ingraham said. “No matter how much an exoskeleton helps, people won’t wear them if they don’t feel good.”
The study was published online in the journal Scientific robotics.