Process, computer program, device and ventilation system for the detection of a leak in a patient gas module

Patent metadata

Field	Value
Publication number	US-11717633-B2
Application number	US-201816771632-A
Country	US
Kind code	B2
Filing date	Dec 12, 2018
Priority date	Dec 15, 2017
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

A process (10), with a computer program, a device (30) and a ventilation system (40) detect a leak in a patient gas module, which suctions and analyzes a continuous sample gas stream from a ventilated patient (20), in a ventilation system for ventilating a patient (20). The process includes a determination (12) of a first time curve of a carbon dioxide concentration in a breathing gas mixture of the patient (20) and the determination (14) of a second time curve of a concentration of another gas in the breathing gas mixture, which gas is different from carbon dioxide. The process (10) further includes a determination (16) of a statistical similarity indicator between the first time curve and the second time curve and the detection (18) of the leak based on the similarity indicator.

First claim

The invention claimed is:

1. A process for the detection of a leak in a patient gas module, which suctions and analyzes a continuous sample gas stream from a ventilated patient, the process comprising the steps of:
determining a first time curve of a carbon dioxide concentration in a breathing gas mixture of the patient;
determining a second time curve of a concentration of an other gas in the breathing gas mixture, which other gas is different from carbon dioxide;
determining a statistical similarity indicator between the first time curve and the second time curve; and
detecting the leak based on a change of the similarity indicator, wherein the similarity indicator measures a phase shift between the first curve and the second curve.

2. A process in accordance with claim 1 , wherein the other gas is oxygen, nitrous oxide or an anesthetic gas.

3. A process in accordance with claim 1 , wherein the determination of the similarity indicator comprises determining a deformation in the first curve or in the second curve, which determined deformation is peculiar to a leak.

4. A process in accordance with claim 1 , wherein the similarity indicator is an indicator of a symmetry between the first curve and the second curve.

5. A process in accordance with claim 1 , wherein the similarity indicator is a covariance between the first time curve and the second time curve of the concentrations.

6. A process in accordance with claim 1 , wherein the similarity indicator is a covariance between concentration changes of the first time curve and the second time curve.

7. A process in accordance with claim 1 , further comprising the step of comparing the similarity indicator with a threshold value, wherein the detection of the leak is based on the threshold value comparison.

8. process in accordance with claim 7 , further comprising a calibration of the threshold value based on a reference measurement at the ventilation system without a leak.

9. A process in accordance with claim 1 , further comprising the step of determining a run time of the breathing gas mixture from the patient via a sample gas line to a patient gas module.

10. A process in accordance with claim 9 , further comprising the step of:
determining a run time of concentration changes in the breathing gas mixture; and
determining a similarity indicator based on the run times.

11. A process in accordance with claim 10 , further comprising the step of determining the run time based on concentration changes over time or based on an analysis of concentration changes before and after the beginning of breathing phases.

12. A process in accordance with claim 1 , further comprising the step of carrying out a pressure measurement at the ventilation system when a leak was detected.

13. A process in accordance with claim 1 , further comprising the steps of:
providing a program code for carrying out at least one of the steps of determining the first time curve, determining the second time curve, determining the statistical similarity indicator and detecting the leak; and
executing the program code on a computer, on a processor or on a programmable hardware component.

14. A device for detecting a leak in a patient gas module, which the patient module suctions and analyzes a continuous sample gas stream from a ventilated patient, the device comprising:
a signal connection for receiving data of carbon dioxide concentration in a breathing gas mixture of the patient and receiving data of an other gas concentration in the breathing gas mixture, which other gas is different from carbon dioxide; and
a processor connected to the signal connection and configured to:
determine a first time curve of a carbon dioxide concentration in a breathing gas mixture of the patient from the received data of carbon dioxide concentration;
determine a second time curve of a concentration of the other gas in the breathing gas mixture gas of the patient from the received data of the other gas concentration;
determine a statistical similarity indicator between the first time curve and the second time curve; and
detect the leak based on a change of the similarity indicator, wherein the similarity indicator measures a phase shift between the first curve and the second curve.

15. A device in accordance with claim 14 , wherein the other gas is oxygen, nitrous oxide or an anesthetic gas.

16. A device in accordance with claim 14 , wherein the processor is further configured to compare the similarity indicator with a threshold value, wherein the detection of the leak is based on the threshold value comparison.

17. A device in accordance with claim 14 , wherein the similarity indicator is a covariance between the first time curve and the second time curve of the concentrations.

18. A device in accordance with claim 14 , wherein the processor is further configured to determine a run time of the breathing gas mixture from the patient to a patient gas module, via a sample gas line.

19. A ventilation system comprising:
a ventilation arrangement with a patient connection for ventilating the patient;
a patient gas module configured to suction and analyzes a continuous sample gas stream from the patient connection and to output data of carbon dioxide concentration in a breathing gas mixture of the patient and data of an other gas concentration in the breathing gas mixture of the patient, which other gas is different from carbon dioxide; and
a device for detecting a leak in a patient gas module, the device comprising:
a signal connection for receiving data of carbon dioxide concentration in a breathing gas mixture of the patient and receiving data of another gas concentration in the breathing gas mixture, which other gas is different from carbon dioxide; and
a processor connected to the signal connection and configured to:
determine a first time curve of a carbon dioxide concentration in a breathing gas mixture of the patient from the received data of carbon dioxide concentration;
determine a second time curve of a concentration of the other gas in the breathing gas mixture gas of the patient from the received data of the other gas concentration;
determine a statistical similarity indicator between the first time curve and the second time curve; and
detect the leak based on a change of the similarity indicator, wherein the similarity indicator measures a phase shift between the first curve and the second curve.

20. A ventilation system in accordance with claim 19 , wherein the other gas is oxygen, nitrous oxide or an anesthetic gas.

Assignees

• Draegerwerk Ag & Co Kgaa

Inventors

• Peter Gerd
• Schmid Uwe
• Osterloh Christoph

Classifications

• A61M16/085 Primary

  Gas sampling · CPC title

• A61B5/0836

  Measuring rate of CO2 production · CPC title

• A61M16/0066

  Blowers or centrifugal pumps · CPC title

• A61M16/0808

  Condensation traps · CPC title

• A61M16/0833

  T- or Y-type connectors, e.g. Y-piece · CPC title