Tag Archives: prosthetics

Pimp my prosthesis

For my money, a sure mark of a technology reaching maturity (and market acceptance) is when the purely aesthetic customisation options start to appear

bespoke prosthetic leg

Bonus future-points for the fact that these are being made using rapid prototyping / 3d printing technology. Mass production, pah!

[ Can’t actually remember whose Google Reader recommendations this piece came out of, so – whoever it was – please accept my apologies and an ambiguously-directed hat-tip. ]

In prosthetics, one size does not fit all

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…

Replacement arms: mechanical or biological?

Prosthetic limbs are still in their infancy, but there’s a lot of progress being made: Johns Hopkins Applied Physics Laboratory is working with Darpa (who else?), and has a research grant for trying out their mind-controlled modular prosthetic arm on five test subjects over the next couple of years [via SlashDot]:

Phase III testing – human subjects testing – will be used to tweak the system, both improving neural control over the limb and optimizing the algorithms which generate sensory feedback. The Modular Prosthetic Limb (MPL) is the product of years of prototype design – it includes 22 degrees of motion, allows independent control of all five fingers, and weighs the same as a natural human arm (about nine pounds). Patients will control the MPL with a surgically implanted microarray which records action potentials directly from the motor cortex.

Researchers plan to install the first system into a quadriplegic patient; while amputees can be outfitted with traditional prostheses, the MPL will be the first artificial limb that can sidestep spinal cord injury by plugging directly into the brain.

Great news, then, but it’s still a crude kludge compared to the original. Building a new biological limb from the ground up is way beyond our biotech capabilities as they stand… but our own bodies do a pretty good job of it when we’re developing in the womb, and young children can sometime regrow fully functional fingertips lost to accidents. So why can’t we make like salamanders and just sprout replacement limbs? It’s a vexing question, and extremely clever people are working hard to work out the answer. (You’ll have to go read the whole article, because it’s too full of proper science for one or two pulled paragraphs to do it justice.)

Bionic legs put wheelchairs on notice

OK, so the wheelchair won’t be obsolete until the REX system and its inevitable competitors are a great deal cheaper than US$150k, but I feel safe in assuming that won’t take too long in the grand scheme of things. Even so, as a proof of concept for technology that will allow people with paralysis of the legs to walk – actually walk, not just get around some other way – this is some sweet hardware; as a commenter at MetaFilter put it: “Jokes aside, even though the functionality is fairly constrained, the smile on his face says it’s worth it.” I’m inclined to agree.

Bacterial biker jackets and after-market parts for people

This year seems like it’ll be the one where the mainstream starts talking about custom-made replacement organs as something more than science fiction. A few weeks back we heard about the rat who got a new set of lab-grown lungs; this week, Wired is running a photo-essay on bioprinting that’s a must-see for anyone who wants to be able to write a plausible description of the working environment of a contemporary Frankenstein.

Bioreactor - image credited to Dave Bullock/Wired.com

Meanwhile [via BoingBoing] Ecouterre reports on UK-based designer Suzanne Lee, who’s been using bacteria to grow an entire range of clothing from a rather mundane starting point – sweetened green tea. The end results are made entirely of cellulose, though they look (to me at least) like the skin of something that still slinks through radiation-soaked cities long after the posthumans abandoned Earth for the new terrain at the top of the gravity well…

Bio-couture jacket by Suzanne Lee

Organic ain’t yer only option, though, no sir. 3D printing means one-off custom designs of mechanical prosthetic limb can be made for amputees or other folk with different levels of physical ability… and not just for us longpigs, either, as Oscar the cyborg cat ably demonstrates. 3D printing is still an unevenly distributed piece of the future, of course, but it’s spreading fast; Ponoko have just set up their first 3D print hub here in the UK, and if they can afford to do that in the current economic climate, the business model must have something going for it, right?

It’s interesting to see the organic and inorganic racing along in parallel like this; it doesn’t take a genius to see the possibilities of the two streams converging somewhere down the line, though I’d guess that’s a good few decades off from the present day. What’s interesting to me about these phenomena is the way they seem to be an end-game expression of the desire for individuality and customisation; at the moment, price will keep all but those with a serious need for these products out of the market, but as prices fall, everything will become bespoke, unique, a one-off. Which is kind of ironic if you think about it: through the total ubiquity of mechanised manufacture, we’re actually putting an end to mass production.