This could allow option of key splitting like encryption keys. For example, my key will always work to open my lock, but I also have the option of having any 3 friends out of 10 I designate combine keys to allow my lock to open. This would be handy for getting locked out...just call the n number of neighbors you trusted with parts of you split key to meet you at the door.
I'll be thirsty after the long ride.
Fetal scalp electrodes are used for internal (in the uterus) monitoring of a fetus during labor. They are inserted through the cervix and short electrodes "screw" gently into the scalp of the fetus. The concept is fairly old, I think.
With your bare hands?!?