Systems and methods for delivery of therapeutic gas
Therapy gas delivery systems that provide run-time-to-empty information to a user of the system and methods for administering therapeutic gas to a patient. The therapeutic gas delivery system may include a gas pressure sensor attachable to a therapeutic gas source that communicates therapeutic gas pressure data to a therapeutic gas delivery system controller, a gas temperature sensor positioned to measure gas temperature in the therapeutic gas source that communicates therapeutic gas temperature data to the therapeutic gas delivery system controller, at least one flow controller that communicates therapeutic gas flow rate data to the therapeutic gas delivery system controller, at least one flow sensor that communicates flow rate data to the therapeutic gas delivery system controller, and at least one display that communicates run-time-to-empty to a user of the therapeutic gas delivery system. The therapeutic gas delivery system controller of the system includes a processor that executes an algorithm to calculate the run-time-to-empty from the data received from the gas pressure sensor, temperature sensor, flow controller and flow sensor, and directs the result to the display.
1. A method of providing therapeutic gas from a secondary delivery subsystem, comprising:
detecting a problem with a primary gas delivery system configured to deliver a therapeutic gas flow;
automatically switching therapeutic gas flow control to a flow control channel of the secondary delivery subsystem, wherein the flow control channel is operable to receive the therapeutic gas flow and is in fluid communication with a secondary shut off valve, a secondary flow control valve, a secondary delivery flow sensor, and a secondary confirmatory flow sensor; and
switching a flow regulating valve to deliver the therapeutic gas to a primary outlet, a low pressure outlet, and an injector module, wherein the flow regulating valve is at a blending junction and is in fluid communication with the flow control channel.
2. The method of claim 1 , further comprising:
receiving a set dose of therapeutic gas from a primary gas delivery subsystem of the primary gas delivery system;
receiving a flow value from the secondary delivery flow sensor and/or a secondary confirmatory flow sensor;
calculating a flow rate of the therapeutic gas through the low pressure delivery flow sensor or the low pressure confirmatory flow sensor to provide a dose of the therapeutic gas exiting the blending junction; and
comparing the dose of the therapeutic gas exiting the blending junction to the set dose.
3. The method of claim 2 , wherein the calculated dose of therapeutic gas is calculated using a known concentration of the therapeutic gas from a therapeutic gas source, the amount of low pressure oxygen and/or air using information from the secondary delivery flow sensor and/or the secondary confirmatory flow sensor, and the amount of therapeutic gas flow from flow control channel going to the blending junction using information from the secondary delivery flow sensor and/or the secondary confirmatory flow sensor.
4. The method of claim 1 , wherein the problem detected is loss of communication with the primary gas delivery system, a failure in one or more of the flow control channels of primary gas delivery system, failure at a gas analyzer of the primary gas delivery system, or power failure of the primary gas delivery system.
5. The method of claim 4 , wherein the secondary delivery subsystem has its own internal battery backup separate from a main system battery.
6. The method of claim 1 , further comprising:
performing ratio-metric calculations for a concentration of therapeutic gas being delivered based on flow values from the secondary delivery flow sensor and/or the secondary confirmatory flow sensor, and from an injector module delivery flow sensor and/or an injector module confirmatory flow sensor.
7. The method of claim 6 , wherein the secondary delivery flow sensor and/or the secondary confirmatory flow sensor provides monitoring of the secondary delivery subsystem that comprises 3 sets of sensors for triangulation of failure, including the injector module delivery flow sensor and/or the injector module confirmatory flow sensor, the secondary delivery flow sensor and/or the secondary confirmatory flow sensor, and the therapeutic gas sensor.
8. The method of claim 7 , further comprising:
comparing flow rate values from the injector module delivery flow sensor and/or the injector module confirmatory flow sensor, the secondary delivery flow sensor and/or the secondary confirmatory flow sensor, and the therapeutic gas sensor;
comparing the ratio-metric concentration of therapeutic gas to a set concentration of therapeutic gas; and
determining if any components of the primary gas delivery subsystem or the secondary gas delivery subsystem have failed based on the comparisons.
9. The method of claim 1 , further comprising generating an alert to a user if a problem is detected.
10. The method of claim 9 , further comprising generating an alarm signal if flow values from the low pressure confirmatory flow sensor and the low pressure delivery flow sensor are not about the same.
11. The method of claim 1 , further comprising communicating pressure values from the pressure sensor to the secondary delivery subsystem controller, and detecting pressure fluctuations in the pressure sensor.
12. The method of claim 11 , further comprising opening an overpressure valve in fluid communication with the primary outlet at a predetermined pressure to avoid pressure surges.
13. The method of claim 1 , wherein the low pressure outlet is operable for connection to a manual ventilation device.
14. The method of claim 1 , wherein the primary outlet is connected to a low pressure inlet port operable for connection to a low pressure air/O2 supply.