Abstract: A plasma treatment probe may include a hollow, tubular electrode defining an interior region, and a coaxial insulating tube configured to enclose the electrode. The insulating tube may form a gas flow outlet at one end. An outer chamber may enclose the insulating tube and the hollow electrode, and may have a gas inlet for receiving a gas mixture. The hollow electrode may be configured to receive nanosecond electric pulses, while a gas mixture flows from the gas inlet through the interior region of the electrode, so that a non-thermal plasma can be ignited that exits from the gas flow outlet onto a region of a patient's body to medically treat the region.