1. The website you found the video doesn't look very credible
2. How does the blade know the difference between your finger and a piece of wood? You really can't tell.
3. I did a google search and couldn't find anything supporting this video.
well the site puts everything that could be funny to someone, there is a good chance that it was doctored, but I thought that they would have someone researching that very thing, cause that tool would be the standard if made.
My firewall is blocking the video, and I really don't want to disable it, but I think I know of this technology...in fact I know the company that developed it. I am also under a legal obligation not to say how it works. I can only say that it is possible to tell a finger from a piece of wood. It is a very clever idea. This particular site may or may not be showing the same thing that I know about, but it sure sounds like it. The demonstration sounds identical to the one used by my customer.
You will see this technology applied more generally soon. I assume that the demand for secrecy was due to patent issues. Of course, sometimes these things just get silly. For a long time I couldn't use the word "Wahoos" either - a new General Mills product - but this was supposed to be a really big deal.
http://www.sawstop.com/video.htm [Broken] is the source of the video. A little more respectable. Ivan if this is not the same as your source then there has been some industrial espionage going on.
Oh yeah. It imposes a AC signal on the blade, flesh has much different electrical properties then wood, when the changes a mechanical brake is engaged stopping the blade in less then 5ms. They have similar systems for band saws.