In prosthetics, one size does not fit all

Paul Raven @ 28-09-2010

Here’s an interesting piece at Wired UK; a group of prosthetic limb specialists were doing some final user-satisfaction research, and discovered that the all-singing-all-dancing does-it-all-for-you system they’d made wasn’t what the users really wanted, and for very different reasons:

In addition to weakening physical control, MS often impairs attention and memory, and the complexity of the arm’s controls overwhelmed them. At that time, the arm’s sensors and AI were much more limited, and users were mostly frustrated by its complicated controls.

For these patients, according to Behal, something that might seem as simple as scratching their heads was a prolonged struggle. They needed something that took the guesswork of movement, rotation, and force out of the equation.

The quadriplegics at Orlando Health were the opposite. They were cognitively high-functioning, and some had experience with computers or video games. All had ample experience using assistive technology. Regardless of the extent of their disability or whether they were using a touchscreen, mouse, joystick, or voice controls, they preferred using the arm on manual. The more experience they had with tech, the happier they were.

Anyone with commercial tech experience, even if only in retail, will be aware that one size (or in this case, one functionality) very rarely fits all; interesting to see that revelation filtering in to medical tech research. The more canny crews will start working closely with potential usergroups earlier in the development cycle.

They’re being philosophical about it, though:

“We stay engaged when our capabilities are matched by our challenges and our opportunities,” Bricout said. If that balance tilts too far to one direction, we get anxious; if it tilts to the other, we get bored. Match them, and we’re at our happiest, most creative, and most productive.

Behal and Bricout hadn’t anticipated, for example, that users operating the arm using the manual mode would begin to show increased physical functionality.

“There’s rehabilitation potential here,” Bricout said. Thinking through multiple steps to coordinate and improve physical actions “activated latent physical and cognitive resources… It makes you rethink what rehabilitation itself might mean.”

There’s your silver lining, huh? But it’s still a bit depressing to see this as the closer:

“You have to listen to users,” Behal said. “If they don’t like using the technology, they won’t. Then it doesn’t matter how well it does its job.”

How has it taken that lesson so long to reach the technological wings of the academy? Still, better late than never, I guess…