Sub-nanosecond electrical pulses for medical therapies and imaging

Nanosecond electrical pulses have been successfully used to treat subcutaneous tumors with needle arrays as pulse delivery systems. Reducing the pulse duration into the subnanosecond range enables driving wideband radiation sources, which can deliver high electric fields deep into the body. This electromagnetic energy may be used to stimulate bioelectric effects, such as electrical activation of platelets for hemostasis or electric field induced apoptosis of tumor cells. To this end we have investigated the biological response to sub-nanosecond pulsed electric fields. With the goal of ultimately delivering electric field exposures with an impulse radiating antenna (IRA), we have developed a 150-ps, 50-kV pulse generator and concurrently studied the radiation characteristics of the prolate-spheroidal antennas, when excited by such a pulse. In addition to applying using ultrashort electrical pulses for medical therapies, the use of Impulse Radiating Antennas in the hundred-picosecond temporal range lead us to medical imaging methods with sub-centimeter spatial resolution.