VENTILATOR WITH LIMP MODE

• US 20110209706A1
• Filed: 10/09/2009
• Published: 09/01/2011
• Est. Priority Date: 10/16/2008
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Duff, Winslow K., McDermott, Mark C., Truschel, William A., Shissler, Andrew L., Kissel, Michael H.
• Granted Patent: US 8,714,152 B2
• Time in Patent Office: Days
• US Class Current: 128/204.23
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/0063 Compressors
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2016/0042 in the expiratory circuit
• CPC Class Codes: A61M 2205/16 with back-up system in case of failure
• CPC Class Codes: A61M 2205/17 with redundant control systems
• CPC Class Codes: A61M 2205/3358 Measuring barometric pressure, e.g. for compensation

Abstract

A method of operating a ventilator that includes steps of (a) providing a specified ventilation therapy to a patient through a ventilator according to a specification; (b) determining and storing a backup parameter relating to the operation of the ventilator or the breathing of the patient during the step of providing the specified ventilation therapy; (c) determining that an alarm condition exists that indicates a problem with the ventilator that would prevent the ventilator from providing the specified ventilation therapy to the patient according to the specification; and (d) responsive to determining that the alarm condition exists, providing backup ventilation therapy to the patient through the ventilator that is based at least partially on the stored backup parameter. Also, a ventilator that is adapted to perform the method just described.

Claims

1. A method of operating a ventilator, comprising:

(a) providing a specified ventilation therapy to a patient through a ventilator according to a specification;

(b) determining and storing a backup parameter relating to past operation of the ventilator having occurred while the specified ventilation therapy was being provided to the patient or past breathing of the patient having occurred while the specified ventilation therapy was being provided to the patient;

(c) determining that an alarm condition exists, wherein the alarm condition indicates a problem with the ventilator that would prevent the ventilator from providing the specified ventilation therapy to the patient according to the specification; and

(d) responsive to determining that the alarm condition exists, providing backup ventilation therapy to the patient through the ventilator, wherein one or more particular parameters of the backup ventilation therapy is determined based at least partially on the stored backup parameter.

2. The method according to claim 1, wherein the step of determining and storing the backup parameter includes calculating an average of an operational parameter of the ventilator or a breathing parameter of the patient over a predetermined number of breaths taken by the patient during the step of providing the specified ventilation therapy.

3. The method according to claim 2, wherein the ventilator includes a flow generator, and wherein the backup parameter includes one or more of (1) an average generator speed during IPAP delivery over the predetermined number of breaths, (2) an average generator speed during EPAP delivery over the predetermined number of breaths, (3) an average IPAP level delivered to the patient over the predetermined number of breaths, (4) an average EPAP level delivered to the patient over the predetermined number of breaths, (5) a patient breath rate average over the predetermined number of breaths, and (6) a patient inspiration time average over the predetermined number of breaths.

4. The method according to claim 2, wherein the ventilator includes a flow generator, and wherein the backup parameter includes (1) an average generator speed during IPAP delivery over the predetermined number of breaths, (2) an average generator speed during EPAP delivery over the predetermined number of breaths, (3) an average IPAP level delivered to the patient over the predetermined number of breaths, (4) an average EPAP level delivered to the patient over the predetermined number of breaths, (5) a patient breath rate average over the predetermined number of breaths, and (6) a patient inspiration time average over the predetermined number of breaths.

5. The method according to claim 2, further comprising determining whether each of the predetermined number of breaths is a valid breath, wherein the step of determining and storing the backup parameter is performed only if each of the predetermined number of breaths is determined to be a valid breath.

6. The method according to claim 5, wherein the step of determining and storing the backup parameter is repeated each time a new valid breath is taken by the patient such that the backup parameter is re-determined and re-stored for the most recent in time of the predetermined number of breaths.

7. The method according to claim 1, wherein the alarm condition indicates a hardware problem with the ventilator that would prevent the ventilator from providing the specified ventilation therapy to the patient according to the specification.

8. The method according to claim 7, wherein the ventilator includes a sensor, and wherein the alarm condition indicates a problem with the sensor.

9. The method according to claim 7, wherein the ventilator comprises a patient circuit for transporting gas to and from the patient and wherein the alarm condition indicates a problem relating to the patient circuit.

10. The method according to claim 1, wherein the ventilator includes a flow generator, and wherein the backup ventilation therapy is either (i) a flow generator speed type ventilation therapy using a set flow generator speed or speeds based on the stored backup parameter, or (ii) a pressure support type ventilation therapy using a set pressure level or levels based on the stored backup parameter.

11. The method according to claim 10, further comprising, responsive to and depending on the alarm condition, determining whether the flow generator speed type ventilation therapy or the pressure support type ventilation therapy is to be provided.

12. The method according to claim 11, wherein the ventilator includes a first pressure sensor and a second pressure sensor, wherein the alarm condition indicates that both the first and the second pressure sensors have failed, and wherein, responsive to the alarm condition indicating that both the first and the second pressure sensors have failed, determining the backup ventilation therapy to be the flow generator speed type ventilation therapy.

13. The method according to claim 11, wherein the ventilator includes a first flow sensor and a second flow sensor, wherein the alarm condition indicates that both the first and the second flow sensors have failed, and wherein, responsive to the alarm condition indicating that both the first and the second flow sensors have failed, determining the backup ventilation therapy to be the pressure support type ventilation therapy.

14. A ventilator comprising:

(a) a housing having an interior and an exterior;

(b) an inlet port extending from the exterior to the interior of the housing;

(c) a flow generator disposed within the ventilator and being structured to generate a flow of gas;

(d) an outlet port for discharging the flow of gas from the housing;

(d) a patient circuit in fluid communication with the outlet port and being structured to deliver the flow of gas to an airway of a patient during an inspiratory phase of a ventilatory cycle; and

(f) a controller disposed in the housing and being operatively coupled to the flow generator, the controller being adapted to;

(1) provide a specified ventilation therapy to a patient through the patient circuit according to a specification,

(2) determine and store a backup parameter relating to past operation of the ventilator having occurred while the specified ventilation therapy was being provided to the patient or past breathing of the patient having occurred while the specified ventilation therapy was being provided to the patient,

(3) determine that an alarm condition exists, wherein the alarm condition indicates a problem with the ventilator that would prevent the ventilator from providing the specified ventilation therapy to the patient according to the specification, and

(4) responsive to determining that an alarm condition exists, provide a backup ventilation therapy to the patient through the patient circuit wherein one or more particular parameters of the backup ventilation therapy is determined based at least partially on the stored backup parameter.

15. The ventilator according to claim 14, wherein the controller is further adapted to determine and store the backup parameter by calculating an average of an operational parameter of the ventilator or a breathing parameter of the patient over a predetermined number of breaths taken by the patient while the specified ventilation therapy is being provided.

16. The ventilator according to claim 15, wherein the backup parameter includes one or more of (1) an average generator speed during EPAP delivery over the predetermined number of breaths, (2) an attained EPAP flow generator speed average for the predetermined number of breaths, (3) an average IPAP level delivered to the patient over the predetermined number of breaths, (4) an average EPAP level delivered to the patient over the predetermined number of breaths, (5) a patient breath rate average for the predetermined number of breaths, and (6) a patient inspiration time average over the predetermined number of breaths.

17. The ventilator according to claim 15, wherein the backup parameter includes (1) an average generator speed during EPAP delivery over the predetermined number of breaths, (2) an attained EPAP flow generator speed average for the predetermined number of breaths, (3) an average IPAP level delivered to the patient over the predetermined number of breaths, (4) an average EPAP level delivered to the patient over the predetermined number of breaths, (5) a patient breath rate average for the predetermined number of breaths, and (6) a patient inspiration time average over the predetermined number of breaths.

18. The ventilator according to claim 15, wherein the controller is further adapted to determine whether each of the predetermined number of breaths is a valid breath, and wherein the backup parameter is determined and stored only if each of the predetermined number of breaths is determined to be a valid breath.

19. The ventilator according to claim 18, wherein the controller is further adapted to repeat the determining and storing of the backup parameter each time a new valid breath is taken by the patient through the patient circuit such that the backup parameter is re-determined and re-stored for the most recent in time of the predetermined number of breaths.

20. The ventilator according to claim 14, wherein the alarm condition indicates a hardware problem with the ventilator that would prevent the ventilator from providing the specified ventilation therapy to the patient according to the specification.

21. The ventilator according to claim 20, wherein the ventilator includes a sensor, and the alarm condition indicates a problem with the sensor or a problem relating to the patient circuit.

22. The ventilator according to claim 14, wherein the backup ventilation therapy is either (i) a flow generator speed type ventilation therapy using a set flow generator speed or speeds based on the stored backup parameter, or (ii) a pressure support type ventilation therapy using a set pressure level or levels based on the stored backup parameter.

23. The ventilator according to claim 22, wherein, responsive to and depending on the alarm condition, the controller is further adapted to determine whether the flow generator speed type ventilation therapy or the pressure support type ventilation therapy is to be provided.

24. The ventilator according to claim 23, further comprising a first pressure sensor and a second pressure sensor, the alarm condition indicates that both the first and the second pressure sensors have failed, and wherein, responsive to the alarm condition indicating that both the first and the second pressure sensors have failed, the controller is further adapted to determine the backup ventilation therapy to be the flow generator speed type ventilation therapy.

25. The ventilator according to claim 23, further comprising a first flow sensor and a second flow sensor, wherein the alarm condition indicates that both the first and the second flow sensors have failed, and wherein, responsive to the alarm condition indicating that both the first and the second flow sensors have failed, the controller is further adapted to determine the backup ventilation therapy to be the pressure support type ventilation therapy.