Study of Cold Atmospheric Plasma Jet at the End of Flexible Plastic Tube for Microbial Decontamination

Abstract

Recently, cold atmospheric plasmas have demonstrated very promising antimicrobial activity in vitro and in vivo including selective destruction of tumor cells. However, the size and the rigidity of most plasma systems limit the clinical application for treatments in internal organs or regions with difficult access (e.g., mouth). Here, we report a device that allows ignition of cold He plasma jet at the tip of 1 m long, 3.5 mm diameter, flexible plastic tube. It is connected to a dielectric enclosure where dielectric barrier discharge (DBD) is generated by a low‐frequency AC power supply. A thin wire at floating potential put inside the plastic tube assists the formation of plasma jet at the downstream tube end. The flexible tube can be kept and manipulated by hand without electric shock and thus the plasma jet can be easily directed to a target. Variation of duty cycle of the applied voltage signal allows precise adjustment of the discharge power. The anti‐microbial efficiency of plasma jet system with flexible tube was tested against fungus Candida albicans seeded on agar.

Amplitude-modulated cold atmospheric pressure plasma jet for treatment of oral candidiasis: In vivo study

“…As shown in a previous study [ 27 ] the resulting electric field at the downstream wire tip is high enough to generate plasma, which is launched outside the plastic tube end forming a small “secondary” plasma jet. More information about this arrangement and its operation principle can be found in previous works [ 27 , 28 ]. As already shown [ 27 ] for biomedical applications tube length of 1.0 m is the best choice due to the following reasons.…”

Uniform surface modification of polyethylene terephthalate (PET) by atmospheric pressure plasma jet with a horn-like nozzle

“…To determine the plasma jet mean power we used the Q-V Lissajous method described before [27]. It was adapted for amplitude-modulated voltage signals as reported in our previously work [28]. Basically, the total energy of a high-voltage oscillation group (E T ) was obtained from the area of the Lissajous figure (QxV) and then, it was divided by the burst repetition period (T r ), as shown in Eq.…”

On the development of a deployable cold plasma endoscope

“…Ever since non‐thermal plasma jets showed efficacy in decontamination and wound healing, the idea of plasma medical therapy within the human body has been emerging . Several approaches for generating plasma for medical purposes within or at the end of small flexible tubes were developed in the last decade …”