? Failures in sterilization of critical medical devices may entail significant institutional costs, patient morbidity, and even mortality. Critical medical devices that are heat- and moisture-sensitive require low-temperature sterilization. This research supports the development of a more efficient low-temperature gas plasma sterilizer (GPS). Unlike currently available low-temperature gas plasma sterilizers, the Phygen system relies on the discharge plasma field, rather than chemical vapor (i.e. H202), for sterilization activity. The GPS does not require any facility renovation for installation or operation. Preliminary studies have demonstrated the ability of the GPS to sterilize enclosed lumen test units having smaller diameters of longer lengths than currently available gas plasma systems (135 cm length, 1-mm diameter). Milestones to be completed at the end of Phase I research are identification of surface geometries and materials for which sporicidal inactivation can be achieved using a cycle time of <_ 60 minutes and characterization of the discharge plasma field. The GPS will positively impact healthcare providers, healthcare consumers, and medical device manufacturers. The GPS will reduce the device turnaround time for reprocessing centers, reduce device inventories, and potentially reduce the morbidity and mortality from nosocomial infection. This sterilizer may also provide medical device manufacturers greater flexibility in device design, allowing more use of heat and moisture-sensitive materials and less restrictive device configurations, and lessen their dependence on off-site sterilization vendors. The GPS represents a true gas plasma technology with the ability to sterilize critical medical devices without the toxicities associated with surface residuals or atmospheric emissions. This sterilization method can provide a faster, more reliable, and more economical sterilizer. Sterilization by this methodology may further assist in the clinical management of newly discovered infectious agents, such as prions. ? ?