Dielectric Barrier Discharge for Living Tissue Sterilization

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 recently been demonstrated that direct treatment of smooth surfaces by non-thermal Dielectric Barrier Discharge (DBD) in air is highly effective in killing pathogens. In this study DBD has been investigated mainly for bacteria inactivation. Optical emission spectroscopy measurements reveal that DBD is at room temperature (313.5 ± 7.5 K rotational (gas) temperature). Thus, it is demonstrated that DBD does not heat the gas but provides strong excitation of the gas due to the high energy of the electrons (3360 ± 50 K vibrational temperature). DBD is safe to use on living tissue without elevated temperatures as the lethal effect of DBD on bacteria is proven not to be thermal. Distinct DBDs are compared with charge patterns (Lichtenberg figures) on photo-films. As evident from the Lichtenberg figures, DBD becomes much more uniform as the voltage rise time decreases. Additionally, sterilization effectiveness of DBD has been investigated by applying the plasma on bacteria culture. It was found that DBD treatment can inactivate E.Coli bacteria within a few seconds. Moreover, DBD can create different sub-lethal and selective effects. These results hold significant promise for medical applications such as the sterilization of wound surfaces