Start-up protocols for nitric oxide delivery device
Start-up protocols for a device and method for administering NO is described.
1. A method, comprising:
coupling a cassette configured to provide NO gas to a console containing a pump and a first flow sensor, the cassette coupled to the console such that the first flow sensor is disposed between the cassette and the pump;
closing an output solenoid that is disposed after the cassette, the output solenoid, when open, configured to allow gas, including NO gas, to be conveyed to a patient, closing the output solenoid configured to place the cassette in fluid communication with a second flow sensor disposed between the cassette and an exhaust port;
activating the pump; and
leak testing the cassette by comparing a flow rate measured by the first flow sensor to a flow rate measured by a second flow sensor.
2. The method of claim 1 , further comprising:
removing the cassette; and
operating the pump after removing the cassette to flush the first flow sensor and the second flow sensor.
3. The method of claim 1 , further comprising:
opening the outlet solenoid;
operating the pump to produce a flow of gas that passes through a gas accumulator and a restrictor to abate pressure pulses; and
delivering the gas, including NO gas, to the patient after opening the outlet solenoid.
4. The method of claim 1 , further comprising:
closing a proportional valve disposed between the cassette and the second flow sensor;
operating the pump to increase a pressure in the cassette;
once the pressure in the cassette reaches a threshold, turning off the pump; and
pressure testing a seal between the cassette and the console by measuring a rate at which the pressure in the cassette decreases after turning off the pump.
5. A device, comprising:
a vessel containing liquid N 2 O 4 ;
a heater configured to heat the vessel and the liquid N 2 O 4 contained therein to produce NO 2 gas;
a liquid N 2 O 4 monitor operatively coupled to the heater and configured to monitor at least one of the current or the voltage applied to the heater, the liquid N 2 O 4 monitor configured to determine when the liquid N 2 O 4 in the vessel has been depleted and only NO 2 gas remains based on at least one of a current or a voltage drawn by the heater; and
a leak detector configured to identify a leak based on voltage drawn by a valve in the device.
6. The device of claim 5 , wherein the liquid N 2 O 4 monitor is configured to monitor a temperature of the vessel containing liquid N 2 O 4 .
7. The device of claim 5 , further comprising a NO availability gauge that displays output from the liquid N 2 O 4 monitor.
8. The device of claim 7 , wherein the NO availability gauge is configured to alert a user to replace a cassette that includes the vessel based on a time and temperature history of the vessel.
9. The device of claim 5 , further comprising an NO dosing display in micrograms per minute or parts per million.
10. The device of claim 9 , wherein the NO dosing display is corrected for formation of NO 2 .
11. The device of claim 10 , wherein the NO dosing display is corrected by varying one or more of an amount of O 2 in a sample, a length of the sampling lines, or a volumetric flow rate in the sampling lines.
12. The device of claim 5 , further comprising:
at least one of a leak or blockage detector, the at least one of the leak or blockage detector configured to monitor one or more of a change in the size and frequency of pressure pulses in an output line.
13. A method, comprising
coupling a NO source cassette that includes (i) liquid N 2 O 4 and is configured to produce NO 2 gas and (ii) a conversion cartridge configured to convert the NO 2 gas to provide NO gas to a console such that the NO source cassette is configured to receive air from a pump via an input and provide NO gas via an output;
closing a solenoid between the output of the NO source cassette and a patient interface to isolate the NO source cassette from an exterior of the console;
operating a pump to increase a pressure in the NO source cassette;
once the pressure in the NO source cassette reaches a threshold, turning off the pump; and
pressure testing a seal between the NO source cassette and the console by measuring a rate at which the pressure in the NO source cassette decreases after turning off the pump.