this is actually old technology, i remember seeing it like 5 years ago or so, it wasn't on time warp at the time, and the guy didn't have the balls to do it to his own finger...
i seem to remember the parts, blade and brake, and all the other parts, involved with stopping the blade, that would need to be replaced, cost about 400$ or something... which there was discussion on if it was worth it, but honestly, my finger is worth more than $400, and it's not like you have to pay that once a year or anything, it's only in the unlikely event you DO cut your finger... i've used table saws quite a few times, and never nicked or lost a finger, though i did have a shop teacher who had a lazy eye, one foot turned inwards, a bad limp, and missing 2 fingers, and i believe a testicle... it would work well for him... (the saw)