Patient circuit integrity alarm using exhaled CO2

• US 8,905,019 B2
• Filed: 05/11/2010
• Issued: 12/09/2014
• Est. Priority Date: 05/11/2010
• Status: Active Grant

• Current Assignee: Vyaire Medical 211, Inc. (Becton, Dickinson & Co)
• Original Assignee: CareFusion 207, Inc. (Becton, Dickinson & Co)
• Inventors: Dixon, Paul David, Blansfield, Terry Lee
• Primary Examiner(s): Thanh, Loan H
• Assistant Examiner(s): Lo, Andrew S
• Application Number:
  US12/777,393
• Publication Number:
  US 20110277758A1
• Time in Patent Office: 1,673 Days
• Field of Search: 128/202.22, 12820421-20423, 128/205.23, 244/118.5, 600/529, 600/532
• US Class Current: 128/202.22
• 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 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 16/0833 T- or Y-type connectors, e.g. Y-piece
• CPC Class Codes: A61M 16/12 by mixing different gases
• CPC Class Codes: A61M 16/16 Devices to humidify the respiration air A61M16/1045 takes precedence
• CPC Class Codes: A61M 16/202 electrically actuated
• CPC Class Codes: A61M 16/209 Relief valves
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/0036 in the breathing tube and used in both inspiratory and expiratory phase
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2016/0042 in the expiratory circuit
• CPC Class Codes: A61M 2016/103 the CO2 concentration
• CPC Class Codes: A61M 2205/13 with means for the detection of operative contact with patient, e.g. lip sensor
• CPC Class Codes: A61M 2205/18 with alarm
• CPC Class Codes: A61M 2205/583 by visual feedback
• CPC Class Codes: A61M 2230/432 partial CO2 pressure (P-CO2)

Abstract

A carbon dioxide sensor for use in a respiratory therapy system. The carbon dioxide sensor determines whether a patient interface is fluidly coupled to a patient.

Claims

1. A respiratory therapy system, comprising:

an inspiratory conduit;

an expiratory port;

a patient interface fluidly coupled to the inspiratory conduit and the expiratory port, the patient interface configured to be fluidly coupled to a patient;

a first carbon dioxide sensor fluidly coupled to the expiratory port and configured to determine a first amount of carbon dioxide in a first gas; and

a second carbon dioxide sensor configured to determine a second amount of carbon dioxide in a second gas,

wherein the first carbon dioxide sensor provides an indication of whether the patient interface is fluidly coupled to the patient based on a comparison between the first amount to the second amount.

2. The respiratory therapy system of claim 1, wherein the first carbon dioxide sensor measures an amount of carbon dioxide over a period of time and compares the amount to a threshold, the period of time being based on a characteristic of the patient.

3. The respiratory therapy system of claim 1, wherein the first carbon dioxide sensor is connected to the patient interface.

4. The respiratory therapy system of claim 1, wherein the first carbon dioxide sensor is connected to the expiratory port.

5. The respiratory therapy system of claim 1, further comprising:

a ventilator providing gas to the inspiratory conduit and receiving exhaled gas from the expiratory port through an expiratory conduit, wherein the first carbon dioxide sensor is connected to the ventilator.

6. The respiratory therapy system of claim 1, wherein the second carbon dioxide sensor is fluidly coupled to the inspiratory conduit.

7. The respiratory therapy system of claim 1, further comprising:

an alarm coupled to the first carbon dioxide sensor and configured to be operated if the first carbon dioxide sensor provides an indication that the patient interface is not fluidly coupled to the patient.

8. A respiratory therapy system, comprising:

a ventilator configured to provide inhaled gas to a patient and receive exhaled gas from the patient;

a carbon dioxide sensor configured to determine a first amount of carbon dioxide in the exhaled gas;

a second carbon dioxide sensor configured to determine a second amount of carbon dioxide in a second gas, different than the exhaled gas; and

a controller operably coupled to the carbon dioxide sensor, the controller configured to compare the first amount to a threshold over a period of time and provide an indication of whether the ventilator is fluidly coupled to the patient based on the comparison, the controller further configured to compare the first amount to the second amount to determine a difference, and to compare the difference to a differential threshold.

9. The respiratory therapy system of claim 8, further comprising:

an inspiratory conduit;

an expiratory port;

a patient interface fluidly coupled to the inspiratory conduit and the expiratory port, the patient interface configured to be fluidly coupled to a patient; and

wherein the controller operably coupled to the carbon dioxide sensor provides the indication based on whether the patient interface is fluidly coupled to the patient.

10. The respiratory therapy system of claim 9, wherein the carbon dioxide sensor is connected to the patient interface.

11. The respiratory therapy system of claim 9, wherein the carbon dioxide sensor is connected to the expiratory port.

12. The respiratory therapy system of claim 8, wherein the carbon dioxide sensor is connected to the ventilator.

13. The respiratory therapy system of claim 8, further comprising:

an alarm coupled to the carbon dioxide sensor and configured to be operated if the carbon dioxide sensor provides an indication that the first amount of carbon dioxide has been below the threshold for a period of time.

14. A method of providing respiratory therapy to a patient, comprising:

providing a patient interface configured to be coupled to the patient;

providing gas to the patient interface;

receiving exhaled gas from the patient;

measuring an amount of carbon dioxide in the exhaled gas over a period of time, wherein the period of time is based on a characteristic of the patient; and

providing an indication of fluid coupling between the patient interface and the patient as a function of the amount of carbon dioxide.

15. The method of claim 14, wherein providing the indication further includes comparing the amount to a threshold.

16. The method of claim 14, further comprising:

providing a carbon dioxide sensor connected to the patient interface.

17. The method of claim 14, further comprising:

measuring a second amount of carbon dioxide in a gas other than the exhaled gas;

comparing the first-mentioned amount to the second amount; and

determining if the patient interface is fluidly coupled to the patient as a function of the comparison.

18. The method of claim 14, further comprising:

operating an alarm if the patient interface is not fluidly coupled to the patient.

19. The method of claim 14, wherein the characteristic of the patient comprises at least one of an age of the patient or a health condition of the patient.