HEATED BREATHING CIRCUIT DETECTION

• US 20090107982A1
• Filed: 10/29/2007
• Published: 04/30/2009
• Est. Priority Date: 10/29/2007
• Status: Active Grant

• Current Assignee: Smiths Medical ASD, Inc. (Smiths Group International Holdings Ltd.)
• Original Assignee: Smiths Medical ASD, Inc. (Smiths Group International Holdings Ltd.)
• Inventors: McGhin, Cary E., Mahadevan, Ashok, Snyder, Robert L.
• Granted Patent: US 8,063,343 B2
• Time in Patent Office: Days
• US Class Current: 219/497
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/08 Bellows; Connecting tubes having means for taking samples G01N1/22; Water traps; Patient circuits
• CPC Class Codes: A61M 16/1075 by influencing the temperature A61M16/1045 takes precedence
• CPC Class Codes: A61M 16/1095 in the connecting tubes
• CPC Class Codes: A61M 16/16 Devices to humidify the respiration air A61M16/1045 takes precedence
• CPC Class Codes: A61M 16/162 Water-reservoir filling system, e.g. automatic
• CPC Class Codes: A61M 2205/14 Detection of the presence or absence of a tube, a connector or a container in an apparatus
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/6027 Electric-conductive bridges closing detection circuits, with or without identifying elements, e.g. resistances, zener-diodes

Abstract

A heated breathing circuit detection system verifies the proper set up and connection of a breathing circuit to a heater unit of a humidification system. The detection system automatically detects that the breathing circuit is connected to the heater unit, and the nature of the heating circuit(s) thereof. In one embodiment, the resistance of the heating circuit(s) is determined and compared to an expected resistance or range of acceptable resistances to determine if the heater circuit(s) is properly or actually attached and properly operating. The humidification system also has the ability to determine the delivery mode of the breathing circuit, i.e., whether a single inspiratory limb, or both inspiratory and expiratory limbs, is connected to the heater unit.

Claims

1. A humidification system, comprising:

a heater unit configured to heat liquid contained within a chamber supported by the heater unit;

a breathing circuit fluidly connected to the chamber;

a heating element electrically coupled to the heater unit and supported by the breathing circuit, the heating element being configured to add heat to a gas passing through the breathing circuit; and

a detection system electrically coupled to the heating element, the detection system having a processor configured to determine a resistance of the heating element.

2. The humidification system of claim 1, further comprising a power source configured to supply power to the heating element, the power source having a primary, a first secondary electrically coupled to the heating element, and a second secondary electrically coupled to the processor.

3. The humidification system of claim 2, wherein the detection system further comprises a sensor electrically coupled to the first secondary and the processor, the sensor being configured to apply a signal to the processor that is indicative of a current passing through the heating element.

4. The humidification system of claim 3, wherein the sensor comprises a Hall Effect sensor and the signal applied to the processor comprises a voltage signal.

5. The humidification system of claim 3, wherein the second secondary applies a voltage signal to the processor, and further wherein the processor is configured to determine a voltage of the heating element from the voltage signal applied by the second secondary.

6. The humidification system of claim 5, wherein the processor is configured to determine the resistance of the heating element from the signal applied by the sensor and the voltage signal applied by the second secondary.

7. The humidification system of claim 1, wherein the processor is configured to compare the determined resistance of the heating element to at least one predetermined resistance or range of resistances.

8. The humidification system of claim 2, further comprising a relay electrically coupled to the first secondary and the heating element, the relay being configured to enable and disable power to the heating element in response to the detection system.

9. The humidification system of claim 2, further comprising at least one zero-crossing detector electrically coupled to the first secondary and the processor.

10. The humidification system of claim 9, wherein the detection system is configured to determine a disconnection of the heating element from the heater unit in response to a signal applied from the zero-crossing detector to the processor.

11. The humidification system of claim 9, wherein the detection system is configured to determine a failure of the heating element in response to a signal applied from the zero-crossing detector to the processor.

12. A respiratory system, comprising:

a breathing circuit including at least one of an inspiratory limb and an expiratory limb;

a heating element supported by the at least one inspiratory limb and expiratory limb, the heating element being configured to add heat to a gas passing through the at least one inspiratory limb and an expiratory limb;

a connection device configured to couple with the least one inspiratory limb and expiratory limb; and

indicia associated with the connection device for identifying the presence of the at least one inspiratory limb and expiratory limb, the indicia having an electrical characteristic.

13. The respiratory system of claim 12, further comprising:

a ventilator;

a humidification system fluidly connected to the ventilator, the humidification system including a heater unit configured to heat liquid contained within a chamber supported by the heater unit; and

an inspiratory limb fluidly connected to the chamber.

14. The respiratory system of claim 13, further comprising:

an expiratory limb fluidly connected to the ventilator.

15. A method for detecting a type of breathing circuit in a humidification system, the breathing circuit having a heating element supported thereby, comprising:

determining a resistance of the heating element;

associating at least one predetermined resistance or range of resistances with at least one breathing circuit type; and

comparing the determined resistance of the heating element to the least one predetermined resistance or range of resistances so as to detect the breathing circuit type.

16. The method of claim 15, wherein the breathing circuit type comprises one of adult, pediatric and neonate.

17. The method of claim 15, wherein the determining step comprises:

determining a current passing through the heating element;

determining a voltage of the heating element; and

calculating the resistance of the heating element from the determined current and voltage.

18. The method of claim 17, wherein the current is determined from a voltage signal applied by a Hall Effect sensor.

19. The method of claim 15, wherein the resistance of the heating element is determined prior to substantial heating of the heating element.

20. A method of identifying a breathing circuit connected to a humidification system through a connection device, the breathing circuit having a heating element supported thereby, comprising:

associating indicia with the connection device, the indicia having an electrical characteristic.

21. The method of claim 20, wherein the breathing circuit comprises an inspiratory limb.

22. The method of claim 20, wherein the breathing circuit comprises an inspiratory limb and an expiratory limb.