Single Treatment Disposable Nitric Oxide Delivery

Abstract

A therapeutic level medical gas delivery system includes a pressure regulator with a control point for a flow of medical gas through a critical flow orifice; a variable flow restrictor; and a mixing chamber for the combination of fixed flows.

What is claimed is: 
     
         1 . A therapeutic level medical gas delivery system, comprising:
 a pressure regulator with a control point for a flow of medical gas through a critical flow orifice;   a variable flow restrictor; and   a mixing chamber for the combination of fixed air flows.   
     
     
         2 . A system according to  claim 1 , comprising a vessel loaded with the medical gas at a pressure greater than atmospheric. 
     
     
         3 . A system according to  claim 2 , wherein a vessel size and a vessel pressure control a quantity of medical gas available for patient treatment. 
     
     
         4 . A system according to  claim 2 , wherein the pressure is dependent on a stability of the gas under pressure. 
     
     
         5 . A system according to  claim 2 , wherein the vessel is coupled to a pressure regulator that controls an outlet pressure of the medical gas. 
     
     
         6 . A system according to  claim 5 , wherein the pressure regulator is a diaphragm, wherein the diaphragm and materials that contact the medical gas are of a material without chemical, catalytic or absorptive interaction. 
     
     
         7 . A system according to  claim 5 , wherein the pressure regulator is set to a pressure that maintains a flow rate of the gas through the critical flow orifice at a desired therapeutic level. 
     
     
         8 . A system according to  claim 1 , wherein the critical flow orifice provides a critical flow of nitric oxide gas when the gas reaches sonic condition. 
     
     
         9 . A system according to  claim 1 , wherein an orifice gas flow comprises an absolute pressure ratio of about 0.5, 0.52, 0.528, or 0.53. 
     
     
         10 . A system according to  claim 1 , wherein an orifice downstream absolute pressure (P 2 ) is approximately 52.8 per cent of an upstream absolute pressure (P 1 ). 
     
     
         11 . A system according to  claim 1 , wherein a gas velocity of the gas through the orifice remains constant as the ratio becomes smaller while a mass flow rate is increased. 
     
     
         12 . A system according to  claim 1 , wherein an orifice pressure into the orifice at a fixed value is maintained to create a constant mass flow of a nitric oxide gas. 
     
     
         13 . A system according to  claim 1 , wherein the mixing chamber dilutes a fixed mass flow rate to a specified therapeutic level using patient inhalations. 
     
     
         14 . A method of delivering medical gases at therapeutic levels to patients comprising:
 providing a vessel that contains nitric oxide at a specified pressure;   controlling the pressure for controlled mass flow through a critical flow orifice;   controlling the air dilution flow via patient inhalation controlled by a variable restrictor; and   maintaining concentration of medical gas through mixing of two fixed mass flows.   
     
     
         15 . A method according to  claim 14 , comprising a vessel initially loaded with the medical gas at a pressure greater than atmospheric. 
     
     
         16 . A method according to  claim 15 , wherein a vessel size and a vessel pressure control a quantity of medical gas available for patient treatment. 
     
     
         17 . A method according to  claim 15 , wherein the pressure is dependent on a stability of the gas under pressure. 
     
     
         18 . A method according to  claim 15 , wherein the vessel is coupled to a pressure regulator that controls an outlet pressure of the medical gas. 
     
     
         19 . A method according to  claim 18 , wherein the pressure regulator is a diaphragm, wherein the diaphragm and materials that contact the medical gas are of a material without chemical, catalytic or absorptive interaction. 
     
     
         20 . A method according to  claim 18 , wherein the pressure regulator is set to a pressure that maintains a flow rate of the gas through the critical flow orifice at a desired therapeutic level. And wherein the critical flow orifice provides a critical flow of nitric oxide gas when the gas reaches sonic condition.