Method of detecting errors in the connections in a humidification system
Various control methods can indirectly determine incorrect connections between components in a respiratory therapy system. For example, errors in the connections can occur between a patient interface, a humidifier and/or a gases source. The methods can indirectly detect if a reverse flow condition exists or other error conditions. A reverse flow condition can occur when gases flows in a direction different from an intended direction of flow. The detection of the reverse flow condition can be indicative of likely errors in connections between the humidifier, patient interface and/or gases source.
1. A method of detecting reverse flow in a respiratory humidification system, the method comprising:
using one or more hardware processors of the humidification system to control circuitry configured to power a heating element of the humidification system, providing electrical power to the heating element, the humidification system further comprising a gases source, a humidifier including an inlet and an outlet, and an inspiratory conduit including an inspiratory conduit heat source, the humidifier further including a humidifier heat source;
comparing a first temperature gradient measured by a first sensor downstream of the heating element with a second temperature gradient measured by a second sensor upstream of the heating element, the first and second sensors in electrical communication with the one or more hardware processors; and
outputting to a display of the humidification system an indication of reverse flow conditions when the second temperature gradient is higher than the first temperature gradient.
2. The method of claim 1 , further comprising:
providing another electrical power to a humidifier heat source of the humidifier of the humidification system;
receiving sensor data from a humidifier heat source temperature sensor at or near the humidifier heat source, the humidifier heat source temperature sensor in electrical communication with the one or more hardware processors;
comparing a temperature gradient at the humidifier heat source with a threshold temperature gradient; and
outputting to the display of the humidification system an indication of humidifier water-out condition when the temperature gradient at the humidifier heat source is higher than the threshold temperature gradient.
3. The method of claim 1 , wherein the method further comprises prior to comparing the first temperature gradient with the second temperature gradient, controlling a duty cycle to the inspiratory conduit heat source.
4. The method of claim 3 , wherein the method further comprises controlling the duty cycle to the inspiratory conduit heat source to 100%.
5. The method of claim 1 , wherein the method further comprises prior to comparing the first temperature gradient with the second temperature gradient, controlling a duty cycle to the humidifier heat source.
6. The method of claim 5 , wherein the method further comprises controlling the duty cycle to the humidifier heat source to 0%.
7. The method of claim 1 , wherein the method further comprises interrupting a therapy that is run on the humidification system when indicating reverse flow conditions in the humidification system, the therapy being a respiratory or ventilation therapy or a humidification therapy.
8. The method of claim 7 , wherein the method further comprises resuming the therapy after outputting the indication of reverse flow conditions and rectifying the reverse flow conditions.
9. The method of claim 1 , wherein the method further comprises alerting a user of the indication of reverse flow conditions, the alerting comprising one or both of: providing one or more audible alarms, text message, images, or a combination thereof; or providing instructions for resolving the reverse flow condition.
10. The method of claim 1 , wherein the humidification system comprises an expiratory conduit.
11. The method of claim 1 , wherein the method further comprises checking for a sudden change in a flow rate when outputting the indication of reverse flow conditions and/or when a reverse flow error alarm is activated.
12. The method of claim 11 , wherein the method further comprises disabling the indication of reverse flow conditions if the sudden change in the flow rate is detected.
13. The method of claim 12 , wherein checking for the sudden change in the flow rate comprises detecting whether there is no flow in the respiratory humidification system.
14. The method of claim 1 , wherein the heating element comprises one or both of an inspiratory conduit heat source or a humidifier heat source.
15. A respiratory humidification system with reverse flow detection, the respiratory humidification system comprising:
a gases source configured to provide a source of gases;
a humidifier including an inlet and an outlet, the humidifier configured to humidify air and further including a humidifier heat source to heat a liquid to humidify the gases provided by the gases source;
an inspiratory conduit configured to provide the humidified gases to a user and including an inspiratory conduit heat source, the gases source, humidifier and inspiratory conduit forming at least a part of a breathing circuit;
a first sensor downstream of the humidifier heat source and/or the inspiratory conduit heat source and configured to measure a first temperature;
a second sensor upstream of the humidifier heat source and/or the inspiratory conduit heat source and configured to measure a second temperature; and
a hardware and/or software controller, the hardware and/or software controller in electrical communication with the first and second sensors, the hardware and/or software controller configured to detect an indication of reverse flow conditions in the humidification system by:
providing an electrical power to the humidifier heat source and/or the inspiratory conduit heat source;
comparing a first temperature gradient at the first sensor with a second temperature gradient at the second sensor; and
outputting an indication of reverse flow conditions when the second temperature gradient is higher than the first temperature gradient.
16. The respiratory humidification system of claim 15 , wherein the hardware and/or software controller is further configured to detect a humidifier water-out condition by:
providing another electrical power to the humidifier heat source;
receiving sensor data from a humidifier heat source temperature sensor at or near the humidifier heat source, the humidifier heat source temperature sensor in electrical communication with the hardware and/or software controller;
comparing a temperature gradient at the humidifier heat source with a threshold temperature gradient; and
outputting an indication of humidifier water-out condition when the temperature gradient at the humidifier heat source is higher than the threshold temperature gradient.
17. The respiratory humidification system of claim 15 , wherein the first sensor is located at the outlet of the humidifier or the inlet of the humidifier and the second sensor is located at a patient end of the inspiratory conduit or the outlet of the humidifier.
18. The respiratory humidification system of claim 15 , wherein the hardware and/or software controller is configured to interrupt a therapy that is run on the humidification system when indicating reverse flow conditions in the humidification system, the therapy being a respiratory or ventilation therapy or a humidification therapy.
19. The respiratory humidification system of claim 15 , wherein the hardware and/or software controller is configured to detect an indication of reverse flow conditions in the humidification system further by:
prior to comparing the first temperature gradient with the second temperature gradient, controlling a duty cycle to the inspiratory conduit heat source to 100%.
20. The respiratory humidification system of claim 15 , wherein the hardware and/or software controller is configured to detect an indication of reverse flow conditions in the humidification system further by:
prior to comparing the first temperature gradient with the second temperature gradient, controlling a duty cycle to the humidifier heat source to 0%.