Internal sterilization technique using large-volume microwave plasma in N2-O2 mixture gas with water vapor addition

摘要

In order to sterilize inside the medical instruments wrapped with perforated plastic envelopes, it isrequired to produce the plasma inside the packing or make the effective sterilizing agents penetratethe packing. To solve this problem, we propose to use the volume-wave plasma (VWP) or thesurface-wave plasma (SWP) with water vapor addition to realize the low-temperature internalsterilization effectiveness. In this study, we investigated the internal sterilization technique usinglarge-volume microwave-excited plasmas in N2-O2 mixture gas. Discharge transition between SWPand VWP could be controlled in a 55cm-diam. cylindrical vacuum chamber filled with working gas.Within several tens minutes plasma treatment, sterilization of biological indicators (BIs) withpopulation of 103 to 107 Geobacillus stearothermophilus spores wrapped in a glassine pouch, aTyvek?/poly pouch or wrapped with polyethylene (PE) film were achieved.