School of Electrical Engineering, Dalian University of Technology, Dalian 116024, China.
State Grid Heilongjiang Electric Power Supply Company Limited Economic Research Institute, Harbin 150036, China.
J Appl Microbiol. 2023 Aug 1;134(8). doi: 10.1093/jambio/lxad183.
The medical capillary catheters occupy a high proportion of medical diagnosis, monitoring, and treatment devices, and will cause serious cross-infection without being disinfected adequately. This paper presents a new plasma structure for efficient inactivation of harmful microorganisms in medical capillaries.
An innovative coaxial-dual-gap dielectric barrier discharge reactor powered by nanosecond-pulsed power supply was designed for disinfection of Escherichia coli (E. coli) inside and outside medical capillary catheters in this work. Atmospheric helium plasma (AHP) and atmospheric air plasma (AAP) were successfully obtained inside and outside capillary (0.6 mm inner diameter and 1.0 mm outer diameter), respectively. The electrical and optical characteristics of AHP and AAP were investigated. As the threshold of applied voltage amplitude (Uamp) was <7.0 kV, only one helium glow discharge was generated inside the capillary at the rising and falling stages of pulse voltage. As the Uamp exceeded the threshold, two helium glow discharges were generated that further caused generation of air discharge. Under the Uamp of 9.0 kV, the production of AHP lowered the breakdown voltage in air gap, resulting in the formation of high-volume and uniform AAP, which was conducive to the realization of full inactivation. The inactivation rates of E. coli reached 98.13% and 99.99% by 2 min AHP and 0.5 min AAP treatment, respectively.
The electrical stress of AHP and the reactive oxygen and nitrogen species produced by AAP were contributed to the inactivation of E. coli. The results of SEM (Scanning Electron Microscope) show that plasma treatment can destroy the cellular structure of E. coli.
医用毛细导管在医学诊断、监测和治疗设备中占有很高的比例，如果没有充分消毒，会导致严重的交叉感染。本文提出了一种新的等离子体结构，用于有效灭活医用毛细导管中的有害微生物。
本工作设计了一种基于纳秒脉冲电源的同轴双间隙介电阻挡放电反应器，用于对医用毛细导管内外的大肠杆菌（E. coli）进行消毒。在毛细导管（内径 0.6mm，外径 1.0mm）内外成功获得了大气压氦气等离子体（AHP）和大气压空气等离子体（AAP）。研究了 AHP 和 AAP 的电气和光学特性。当外加电压幅度（Uamp）阈值<7.0kV 时，在脉冲电压的上升和下降阶段，仅在毛细导管内产生一个氦辉光放电。当 Uamp 超过阈值时，会产生两个氦辉光放电，进一步导致空气放电的产生。在 9.0kV 的 Uamp 下，AHP 的产生降低了空气间隙的击穿电压，导致高体积和均匀的 AAP 的形成，这有利于实现完全灭活。AHP 处理 2 分钟和 AAP 处理 0.5 分钟后，大肠杆菌的灭活率分别达到 98.13%和 99.99%。
AHP 的电应力和 AAP 产生的活性氧和氮物种有助于大肠杆菌的灭活。SEM（扫描电子显微镜）的结果表明，等离子体处理可以破坏大肠杆菌的细胞结构。
