[dethswatch]

It doesn't exist because the politicians decided (with the help of the person with the patent) to force it on the public by writing laws that said they all had to have this tech when it became viable.

In addition- just as with airplanes- when your life is on the line if a thing doesn't work, you're very conservative about change (oh please add a battery and electronics...)

Third- it doesn't solve a burning problem- if the market wanted it and without #1, it would be available.