Like any good design idea, you can understand how the Toe Mouse works at a glance–and why it was designed.
Liu Yi created it for those without use of their arms, and the form is based on a blockbuster design we’re all familiar with, the flip-flop. The ergonomic shape allows easy gripping between the big toe and the second toe; sensors underneath each would function as the left and right click.
The only usability quibble I have with the design is that your toes don’t actually move independently–try to move your big toe without moving your second toe right now. But beyond that, this could be pretty great: Regular mice have their range of motion scaled to your computer screen in about a 1:3 ratio, so that you can cover the whole screen without moving your hand around too much. To extend that idea a bit for the Toe Mouse, you could design the range of motion to be larger, to make up for the fact that you can’t move your foot with quite the precision that most can move their hands. That would allow you to make more precise clicks–and your feet always have much more room to roam on the floor before you than a mouse would on your desk.
Unfortunately, even if it seems like a design like this should change the world, it probably won’t: The numbers of people without use of their arms, but with use of their legs, has to be an extremely small subset of those without complete use of their limbs. Rather than paralysis victims, you’d be talking about people who’ve lost arms or hands to injury. Which might be a sizable population, in absolute numbers–but I doubt its large enough for any company to invest in creating a purpose-built piece of consumer electronics, with all the manufacturing and distribution complexity that entails.
And that is why the disabled are so often forced to get by on jury-rigged solutions, rather than well designed products–for now, it’s simply too hard to convince most companies of the market that exists.
So what’s the solution? The best idea I can come up with would be something like Quirky for the disabled. That site allows users to submit designs, which Quirky will manufacture if enough people preorder it. Imagine if those with specialized design problems could submit these to a community, get designs in response, and market it to get it built.