[Blindmath] Tactile Displays?

[Roopakshi Pathania]

Hi all,

The recent discussion on the list regarding the accessibility of Mathematica reminded me of the time when I was personally researching the accessibility of same software. I came across an article about a blind physicist. I realise that there are quite afew around these days, but this particular physicist caught my attention. The article mentions a device used by him that consists of a camera attached to a tactile display with vibrating pins.
My questions is: how does this device operates? Also, is this product in the market or just a personal invention?
The article can be found here.
http://www.wolfram.com/news/strickland.html

Regards
Roopakshi from India