Making plasma medicine available for in-body applications (Vol. 50, No. 1)

Endoscope tip without and with Neon plasma

Ever since non-thermal plasmas showed efficacy in decontamination and wound healing, the idea of deploying plasma medical therapy within the human body emerges. Besides the need for flexibility, small dimensions and biological effectiveness, also a minimal plasma-caused applicator erosion as well as an electrically safe operation mode are necessary. Of course, the endoscopic plasma source must also operate inside hollow cavities independent of the environmental conditions present. Since all requirements need to be fulfilled at the same time, the development task is quite complex.

The present paper tackles those requirements and sets special focus on new approaches for reducing leakage current, increasing the bactericidal efficacy and avoiding material erosion simultaneously. The jet-like plasma at the tube tip is maintained by a capacitively coupled discharge configuration. An additional shielding gas surrounds the jet in order to assure reproducible environmental conditions inside the body. Finally, it is found that a combination of Neon feed gas, CO2 shielding gas and a current limited high voltage supply gives the best bactericidal results and, at the same time, reduces material erosion as well as patient leakage current.

J. Winter, Th. M. C. Nishime, R. Bansemer , M. Balazinski, K. Wende and K.-D. Weltmann, Enhanced atmospheric pressure plasma jet setup for endoscopic applications, J. Phys. D: Appl. Phys. 52, 024005 (2019)