Uniform dielectric barrier discharge with nanosecond pulse excitation for biomedical applications

Abstract

For some period of time the use of plasma in medicine has been limited to thermal discharges for cauterization and dissection. The effects of thermal plasma on tissue are entirely related to local heating. Non-thermal plasma, on the other hand, can have many different modes of interaction with tissue. It has been recently demonstrated that direct treatment of smooth surfaces by non-thermal dielectric barrier discharge (DBD) in air is highly effective in killing pathogens. Moreover, DBD can create different sub-lethal and selective effects. These results hold significant promise for medical applications such as sterilization of wound surfaces. However, a typical DBD in air can be highly non-uniform, particularly on topographically non-uniform surfaces such as in most living tissues. This creates significant limitations for use of DBDs in wound care and other biomedical applications. In this thesis, a novel non-thermal plasma system, namely nanosecondpulsed DBD, has been developed and investigated to address this important limitation. Nanosecond-pulsed DBD is shown to be uniform in air at atmosphericpressure and much more effective in killing bacteria than conventional DBDs, particularly on topographically non-uniform surfaces. Thus, this new plasma system is potentially convenient for in vivo and hospital sterilization cases.%%%%Ph.D., Mechanical Engineering – Drexel University, 2009