Operatrix

op-er-at-rix (p-rtrks)

noun
1. Same as a female operator/operatress.*
The nurse, who was operatrix of the x-ray machine, would have none of my whining or squirming about.

Synonyms: controller, operator, operatress.

* But it somehow sounds more domineering, doesn't it?
** You can see by the draconian eyes on the girl in the picture that she is a little evil.