Low cost CPAP flow generator and humidifier assembly

Patent metadata

Field	Value
Publication number	US-12409283-B2
Application number	US-202117308728-A
Country	US
Kind code	B2
Filing date	May 5, 2021
Priority date	Aug 15, 2005
Publication date	Sep 9, 2025
Grant date	Sep 9, 2025

Abstract

A method for controlling a humidifier of a CPAP device including a controller, the method including controlling a heating element in the humidifier with command signals from the controller, sensing a temperature of a fluid in the humidifier with a sensor in the humidifier that transmits signals to the controller, establishing an acceptable operating range for the signal transmitted to the controller; determining whether the transmitted signal is within the acceptable operating range, if the signal is within the acceptable operating range treating the signal as being indicative of the temperature of the fluid in the humidifier and using the signal to control the heating element, and if the signal is outside of the acceptable operating range, the controller determines the humidifier to be unavailable.

First claim

The invention claimed is:

1. A CPAP device comprising:
a flow generator including a microprocessor;
a humidifier detachably coupled to the flow generator; and
a temperature sensor in communication with the humidifier and configured to provide an output corresponding to a temperature of the humidifier,
wherein the microprocessor is configured to control power supply to the humidifier in accordance with the output of the temperature sensor,
wherein humidification control is performed by the microprocessor without requiring a separate humidification control chip.

2. The CPAP device according to claim 1 , wherein motor control and display control are performed by the microprocessor without requiring a separate motor control IC and display control IC.

3. A CPAP device comprising:
a flow generator including a microprocessor;
an analog-to-digital converter (ADC);
a humidifier detachably coupled to the flow generator; and
a temperature sensor in communication with the humidifier and adapted to produce a voltage signal provided to the flow generator microprocessor via the ADC,
wherein the microprocessor is configured to control power supply to the humidifier in accordance with output of the temperature sensor.

4. The CPAP device according to claim 3 , wherein the ADC is configured to output a converted voltage signal of humidifier temperature (T H ) and the microprocessor is configured to:
compare the converted voltage signal to a maximum permissible temperature of the humidifier (T MAX );
turn off power to the humidifier if the temperature is greater than T MAX ; and
turn on or keep on the power to the humidifier if the temperature is not greater than T MAX .

5. The CPAP device according to claim 4 , wherein the comparison of T H to T MAX is periodically carried out upon expiration of a predetermined time period and, if T H is not greater than T MAX , power is provided to the humidifier for only a fraction of the predetermined time period.

6. The CPAP device according to claim 5 , wherein the fraction is about 5-95% of the predetermined time period.

7. The CPAP device according to claim 5 , wherein the predetermined time period is in a range of about 1-10 seconds.

8. The CPAP device according to claim 5 , wherein the flow generator is in communication with a main power voltage detector, and the fraction is determined in accordance with the detected main power voltage.

9. The CPAP device according to claim 1 , wherein the microprocessor is configured to disable the CPAP device if a main power supply voltage is incompatible with the voltage rating of the CPAP device.

10. The CPAP device according to claim 3 , wherein the ADC is configured to output a converted voltage signal of humidifier temperature (T H ) and the microprocessor is configured to:
compare the converted voltage signal to a temperature range (T R ), and
turn off or keep off power supply to the humidifier if T H is within T R .

11. The CPAP device according to claim 10 , wherein if T H is not within T R , the microprocessor is configured to:
turn off or keep off power supply to the humidifier if T H is greater than a maximum allowable temperature (T MAX ), and if T H is not greater than T MAX , turn on or keep on the humidifier if T H is less than a minimum temperature (T MIN ) and turn off or keep off the power supply to the humidifier if T H is not less than T MIN .

12. The CPAP device according to claim 1 , wherein the microprocessor has a capacity of about 100-150 bytes.

13. The CPAP device according to claim 3 , wherein the microprocessor includes a humidifier control program including a machine readable code configured to determine whether the humidifier is available.

14. The CPAP device according to claim 13 , wherein the microprocessor executes the humidifier control program to:
receive output from the ADC, and
signal whether the humidifier is available based on the ADC output.

15. The CPAP device according to claim 14 , wherein a signal is generated to indicate that the humidifier is not connected if the output from the ADC is not within the possible range of operability of the humidifier.

16. The CPAP device according to claim 14 , wherein a signal is generated to indicate that the humidifier is attached and operational if the output from the ADC is within the possible range of operability of the humidifier.

17. The CPAP device according to claim 15 , wherein the possible range of operability is between about 5°−70° C.

18. The CPAP device according to claim 13 , further comprising a pull-up resistor in communication with the ADC, wherein the ADC provides a signal to the microprocessor having a first value if the humidifier is not available and a second value, different from the first value, if the humidifier is connected and operable.

19. The CPAP device according to claim 18 , wherein the microprocessor includes code to signal availability of the humidifier in accordance with the signal provided from the ADC to the microprocessor via the pull-up resistor.

20. The CPAP device according to claim 18 , wherein power is supplied to the humidifier, and if a converted voltage signal from the ADC to the microprocessor indicates power loss attributable only to the pull up resistor, then a signal is generated to indicate unavailability of the humidifier, and wherein if the converted voltage signal indicates power loss which is different from the power loss attributable only to the pull-up resistor, then a signal is generated to indicate availability of the humidifier.

21. The CPAP device according to claim 18 , wherein power is supplied to the humidifier, and if a converted voltage signal from the ADC to the microprocessor indicates power loss attributable only to the pull up resistor, then a signal is generated to indicate unavailability of the humidifier.

Assignees

• ResMed Pty Ltd

Inventors

• Tang Zhuo Ran
• Tarakci Cem
• Snow John Michael
• Lee Kenneth
• Farrugia Steven Paul
• Doudkine Dmitri Anatolievich
• Smith Ian Malcolm

Classifications

• A61M16/16

  Devices to humidify the respiration air {(A61M16/1045 takes precedence)} · CPC title

• A61M16/024

  including calculation means, e.g. using a processor · CPC title

• A61M2205/3584

  using modem, internet or Bluetooth® · CPC title

• A61M2205/3561

  local, e.g. within room or hospital · CPC title

• A61M2205/3368

  Temperature · CPC title