Inspiratory synthesis of nitric oxide

#This invention related to synthesis of nitric oxide triggered by inspiratory flow.

#Nitric oxide (NO) is crucial to many biological systems, and is known to mediate the control of blood pressure, help the immune system kill invading parasites that enter cells, inhibit division of cancer cells, transmit signals between brain cells, and contribute to the large scale death of brain cells that can debilitate people with strokes or Huntington's disease. Nitric oxide also mediates relaxation of smooth muscle present, for example, in the walls of the blood vessels, bronchi, gastrointestinal tract, and urogenital tract. Administration of nitric oxide gas to the lung by inhalation has been shown to produce localized smooth muscle relaxation to treat bronchial constriction and pulmonary hypertension, pneumonia, etc. in adults and children without systemic side effects.

#Inhaled nitric oxide is a potent local pulmonary vasodilator and bronchodilator that improves the matching of ventilation with perfusion, thereby increasing the injured lungs oxygen transport efficiency and raising the arterial oxygen tension. Nitric oxide combines a rapid onset of action occurring within seconds with the absence of systemic vasodilatory effects. Once inhaled, it diffuses through the pulmonary vasculature into the bloodstream, where it is rapidly inactivated by combination with hemoglobin. Therefore, the bronchodilator effects of inhaled nitric oxide are limited to the airway and the vasodilatory effects of inhaled nitric oxide are limited to the pulmonary vasculature. The ability of nitric oxide to dilate pulmonary vessels selectively provides therapeutic advantages in the treatment of acute and chronic pulmonary hypertension.

#FIG. 1 is a block diagram of a system for producing NO.

#FIG. 2A shows an example of an NO generator.

#FIG. 2B shows an example of an NO generator.

#Like reference symbols in the various drawings indicate like elements.

#As described herein, electrical synthesis of nitric oxide is initiated upon (or before) inspiration to provide in-situ, on-demand production of nitric oxide for therapeutic use. FIG. 1 shows an example of a system 100 for producing NO in a respiratory system. In some examples, a respiratory system includes the trachea of a mammal, a respiratory mask, nasal prongs, a ventilator, or an anesthesia machine, to name a few. A reactant gas (e.g., air, or a 20-90% oxygen mixture in nitrogen) enters an NO generator 102, and a product gas (including NO) exits the NO generator 102. The NO generator 102 includes electrodes 106, a respiration sensor 108, and a controller 110. If the reactant gas is a gas other than air, the NO generator 102 can include an oxygen sensor 112. The oxygen sensor 112 can be an electrode configured to detect the concentration of oxygen in the reactant gas. The electrodes 106 generate sparks in the presence of the reactant gas to produce NO 104, as described herein.

#In some embodiments, the NO generator 102 is portable and wearable. For example, FIG. 2A shows an example of an NO generator 200 for producing NO that can reside within the trachea of a mammal. The device can be placed in the larynx with a fiber bronchoscope, and anchored to the tracheal wall. FIG. 2A depicts a cross-sectional view of a trachea 202 with tracheostomy or endotracheal tube 204 positioned in the trachea 202. The NO generator 200 is coupled to the tracheostomy or endotracheal tube 204. The NO generator 200 includes electrodes 206 and respiration sensor 208. In some examples, the NO generator 200 includes an oxygen sensor 209. The NO generator 200 may include a controller 210 that is coupled to the electrodes 206, the respiration sensor 208, and the oxygen sensor 209. In some examples, the controller 210 is separate from the NO generator 200. The NO generator 200 may include more than one respiration sensor 208.