Nitric oxide (NO) is an FDA-approved pulmonary vasodilator to treat neonates with persistent pulmonary hypertension at a concentration of 20 ppm. Accumulating evidence suggests that breathing high-dose NO (≥ 80 ppm) for brief periods exerts antimicrobial properties. However, inhaled NO (iNO) therapy has been limited due to high cost and complexed delivery system. Recently, we built a lightweight, portable, and economic NO generator that produces up to 80 ppm of NO. We now propose the first prototype of an antimicrobial NO generator (≥ 80 ppm).
We designed a gliding arc plasma NO generator, consisting of two 0.2-mm thick, 10-cm long pure iridium electrodes with 12° angle in between. Inter-electrode gap in the part forming initial discharge was 3-mm. The generation of NO was measured with a chemiluminescent method and nitrogen dioxide (NO2, a potential toxic byproduct during NO generation) was monitored with CAPS (Aerodyne).
The newly developed gliding arc NO generator produces up to 340 ppm of NO with airflow of 5 L/min. The NO2 level was below 3 ppm (EPA safety threshold).
We demonstrated that the gliding arc NO generation device produces safe, high-dose iNO, which can be used as an antimicrobial therapy to treat airway infections.