US Patent 7504066 Ozone plasma medical sterilization

A method for sterilizing at least one item in a chamber, comprising the steps of: disposing the at least one item in the chamber; pumping the atmosphere from the chamber until the atmosphere of the chamber has a pressure of less than ten torr; adding water vapor and ozone to the chamber; and generating electrical discharge in the chamber, such that the electrical discharge produces OH radicals from the water vapor and the ozone so as to contribute to sterilization of at least part of the at least one item.