Generation and Transportation Mechanisms of Chemically Active Species by Dielectric Barrier Discharge in a Tube for Catheter Sterilization

Abstract

The mechanisms of generation and transportation of a chemically active species in a tube generated by dielectric barrier discharge have been analyzed by experimental and computational methods to elucidate the sterilization mechanism. The obtained results are: i) Nitrogen oxide is an important sterilization factor. ii) Two‐dimensional profiles of emission intensities that expand between the wire and ground in a cross section of the tube were generated by streamer propagation and relaxation processes. iii) A twin vortex was induced in the cross section of the tube by the discharge. Chemically active species, probably transported from the discharge region to the upper region of the tube by the twin vortex, were concentrated by the circular flow.

Sterilization Method Using Plasma Discharge Against Biofilm-Producing Pseudomonas aeruginosa on Surface of Contact Lens

“…In recent years, new sterilization methods that use free radicals, active oxygen, and active nitrogen produced by plasma discharge have been studied in industry. Sato et al showed that the inside of catheters can be sterilized at 64°C for 5 min by inserting an electrode into the catheter and generating plasma, and listed nitrogen oxide and oxygen radicals as the sterilizing factors [22]. The present study found that sterilization using plasma produces O 3 , H 2 O 2 , and various chemical species.…”

Applications of Low-Temperature Plasmas

“…The most interesting property of strong localization of atmospheric pressure discharges is the possibility of using the plasma reactivity to treat a welldefined target area. This characteristic can be exploited to access hard-to-reach regions such as the interior of organs through endoscopes (Polak et al 2012) or catheters (Sato et al 2008). Here, we will emphasize two innovative plasma devices used in medical applications.…”

Inactivation of Bacteria by Non-Thermal Plasmas

“…Eto et al (Eto et al, 2008) developed a so-called "linear DBD" with a diameter of 0.2-3 mm and a length of 40 cm and found that 10 6 B. stearothermophilus spores could be killed inside a medical plastic tube at room temperature after 12 minutes of air plasma exposure. Sato et al (Sato et al, 2008) also report on a special type of DBD and demonstrated the efficacy of their DBD for tube sterilization. A photograph of their discharge in a long flexible narrow tube can be found in Figure 10.…”

“…More recently, Hähnel et al (Hahnel et al, 2010) observed that air humidity in a dielectric barrier surface discharge has a significant influence on the bacterial inactivation rate: higher concentration of water vapour in the process gas leads to higher killing rates of micro-organisms. To enable the internal sterilization of complicated medical instruments, such as breathing circuits, catheders and endoscopes, different authors have developed special DBD configurations (Eto et al, 2008, Pointu et al, 2008, Sato et al, 2008. Eto et al (Eto et al, 2008) developed a so-called "linear DBD" with a diameter of 0.2-3 mm and a length of 40 cm and found that 10 6 B. stearothermophilus spores could be killed inside a medical plastic tube at room temperature after 12 minutes of air plasma exposure.…”