The tiger has whiskers which make contact with the skin of any prey it catches.
These can sense when the pulse of animal which has been caught stops.
Today’s invention is an adaptation of this idea, applied to Taser electric stun guns.
In order to make them less dangerous, one taser dart would have an extra wire attached which would monitor the pulse of someone who had been shocked.
If the pulse began to stop, the current would be automatically cut and an alert issued to the user to get them medical help at once.