Nanosecond Pulsed Uniform Dielectric Barrier Discharge for Living Tissue Sterilization and Blood Coagulation

Abstract

Summary form only given. Sterilization of living tissue and sensitive biomaterials require non-thermal plasma. Although there are many ways to generate non-thermal plasma at low pressure of different gases, for living tissue sterilization and blood coagulation uniform plasma in air at atmospheric pressure is crucial. On the other hand, when generating plasma at atmospheric pressure, such as by using RF power, a question arises about temperature. Most kinds of plasmas tend to have higher temperature than safe to use for sensitive treatment because of significant power deposition. Dielectric barrier discharge (DBD) is a very easy and cheap method for building systems and generating non-thermal atmospheric pressure plasma. This technique has been used for ozone production for more than one and a half century. Nevertheless, conventional atmospheric pressure DBDs in air may also have some difficulties to be used for medical treatment. When ignited in air at atmospheric pressure, they assume a filamentary structure because of streamers. These filaments are undesired for sensitive treatments due to having strong local heating effect. Thus DBD has to be more uniform. Latter can be done by applying pulsed power with pulse duration shorter than streamer formation time. To generate atmospheric pressure uniform plasma in air for living tissue sterilization and blood coagulation, we have developed a new nanosecond pulsed DBD system with only few tens of nanosecond pulse width, using point to plane configuration with customized circuit. Nanosecond pulsed DBD was characterized by electrical and spectroscopic analyses. Voltage pulse width was obtained approximately 20 ns at the half height and with 3 kV/ns front. Uniformity of the nanosecond pulsed DBD has been measured qualitatively by using photofilm where Lichtenberg figures of single pulses do not show any trace of filament. Additionally it was observed that discharge ignites uniformly over large range of gap distances (0.1-4 mm). Further details on characterization and results about new uniform DBD will be presented.