Sterilization of Medical Equipment Using Radicals Produced by Oxygen/Water Vapor RF Plasma

The sterilization of medical equipment was performed using low-pressure RF discharge plasma. Oxygen radicals as oxidizing materials for sterilization were produced from oxygen or water vapor. The generation of atomic oxygen and OH radicals was confirmed using the light emission spectra of the plasma. The pressure in the discharge region was varied periodically during inactivation in order to produce radicals effectively and to penetrate the produced radicals into tiny gaps. Medium sheets for microbial detection indicated that the decimal reduction value of active bacillus was 5 and 8 min using oxygen plasma and water vapor plasma with n e =10 9 cm -3 , respectively. Biological indicators clarified that the sterilization of bacilli spores was successful for a treatment time of 90 min.