Methods and apparatus for heart failure treatment

Patent metadata

Field	Value
Publication number	US-10856802-B2
Application number	US-201615017790-A
Country	US
Kind code	B2
Filing date	Feb 8, 2016
Priority date	Oct 17, 2003
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

Methods and apparatus for assessing the condition of and treating patients for heart failure by the delivery of continuous positive airway pressure are disclosed. Treatment of obstruction due to reflex vocal cord closure often experienced by heart failure patients is distinguished from treatment of upper airway obstruction typically associated with Obstructive Sleep Disorder. Treatment may also be implemented by delivering synchronized cardiac pressure oscillations superimposed on a respiratory pressure level to provide assistance for the heart. Heart treatment pressure dose indicator may be calculated for prescribing and monitoring the delivery of treatment. The apparatus may also generate data to track heart failure condition that may be indicative of the degree of severity of heart failure based upon breathing patterns to assist in the diagnosis and management of heart failure patients.

First claim

The invention claimed is:

1. A method for evaluating heart failure in a patient comprising steps of:
delivering, by a blower, breathable gas at a pressure above atmospheric to a patient;
detecting, by a controller, obstructive events experienced by the patient;
varying, by the blower, the pressure of the breathable gas responsive to obstructive events detected by the controller;
determining a heart failure indicator from machine responses to the patient's breathing patterns, said machine responses comprising said responsive pressure variations, said heart failure indicator representing information about the patient's heart condition; and
comparing said heart failure indicator to a prior heart failure indicator determined during a previous treatment session,
wherein said heart failure indicator is analysed to determine a change in said heart failure indicator over time,
wherein said change is a difference between said prior heart failure indicator of said previous treatment session and said heart failure indicator.

2. The method of claim 1 , further comprising measuring an airflow of the patient, wherein said step of determining includes analyzing said airflow to determine an extent of Cheyne-Stokes breathing of the patient.

3. The method of claim 2 further comprising the step of reducing said pressure during a detected episode of Cheyne-Stokes breathing for a predetermined period of time to permit a determination of said heart failure indicator from said predetermined period of time such that a pattern of Cheyne-Stokes breathing can emerge without significant influence from treatment pressure.

4. The method of claim 2 wherein said step of determining includes analyzing said airflow to determine a duration of a waxing and waning cycle.

5. The method of claim 2 wherein said step of determining includes a frequency analysis of said airflow in a range of frequencies indicative of Cheyne-Stokes breathing.

6. The method of claim 5 wherein said frequency analysis of said airflow is in a range of about 1/20 hertz to 1/90 hertz.

7. The method of claim 6 wherein said heart failure indicator includes a magnitude of a component of said airflow at a frequency in said range.

8. The method of claim 7 wherein said heart failure indicator is a sum of magnitudes of components of said airflow in a sub-range of frequencies in said range.

9. The method of claim 5 wherein said frequency analysis of said airflow is performed with data sampled from a measure of ventilation derived from said airflow.

10. The method of claim 9 wherein said measure of ventilation is a minute volume.

11. The method of claim 7 further comprising a step of comparing said magnitude with a threshold value.

12. The method of claim 11 wherein said threshold value is a magnitude derived from a previous frequency analysis.

13. The method of claim 1 further comprising steps of prompting for heart failure monitoring characteristics and recording said heart failure monitoring characteristics and said heart failure indicator in a database.

14. The method of claim 13 wherein one of said heart failure monitoring characteristics is a level of B natriuretic peptide.

15. The method of claim 1 further comprising a step of identifying subsequent heart failure treatment based at least in part upon said heart failure indicator.

16. The method of claim 15 wherein said subsequent heart failure treatment is an increase in pressure of the breathable gas.

17. The method of claim 1 further comprising the step of analyzing said heart failure indicator as a function of a threshold value.

18. The method of claim 1 wherein said indicator is a function of a measure of ventilation.

19. The method of claim 1 further comprising determining a change that is a ratio of a previous heart failure indicator and a subsequent heart failure indicator.

20. The method of claim 1 further comprising a step of generating a warning as a function of said change from said step of analyzing.

21. The method of claim 20 wherein said warning is an audible alarm.

22. The method of claim 1 wherein said indicator is a measure of ventilation.

23. The method of claim 22 wherein said measure of ventilation is a threshold of about 15 L/min.

24. The method of claim 1 wherein said indicator is a ratio of a minimum ventilation and a maximum ventilation.

25. The method of claim 24 wherein the minimum ventilation and maximum ventilation are derived from a measure of minute ventilation.

26. The method of claim 24 wherein the minimum ventilation and maximum ventilation are derived from a measure of tidal volume.

27. An apparatus for evaluation of heart failure in a patient comprising:
a blower for supplying breathable gas to a patient at a pressure above atmospheric; and
a controller adapted and configured to:
detect obstructive events experienced by the patient;
control said blower such that the pressure varies responsive to detected obstructive events;
determine a heart failure indicator from machine responses to the patient's breathing patterns, said machine responses comprising said responsive pressure variations, said heart failure indicator representing information about the patient's heart condition; and
compare said heart failure indicator to a prior heart failure indicator determined during a previous treatment session,
wherein the controller determines a change in said heart failure indicator over time,
wherein said change is a difference between said prior heart failure indicator of said previous treatment session and said heart failure indicator.

28. The apparatus of claim 27 further comprising a flow sensor to generate a flow signal indicative of the patient's airflow, wherein the determining includes analyzing said flow signal to determine an extent of Cheyne-Stokes breathing of the patient.

29. The apparatus of claim 28 wherein the controller is further configured and adapted to reduce said pressure during a detected episode of Cheyne-Stokes breathing for a predetermined period of time to permit a determination of said heart failure indicator from said predetermined period of time such that a pattern of Cheyne-Stokes breathing can emerge without significant influence from treatment pressure.

30. The apparatus of claim 28 wherein the determining comprises analyzing said flow signal to determine a duration of a waxing and waning cycle.

31. The apparatus of claim 28 wherein the determining comprises a frequency analysis of said flow signal in a range of frequencies indicative of Cheyne-Stokes breathing cycle.

32. The apparatus of claim 31 wherein said frequency analysis of said flow signal is in a range of about 1/20 hertz to 1/90 hertz.

33. The apparatus of claim 32 wherein said heart failure indicator includes a magnitude of a component of said flow signal at a frequency in said range.

34. The apparatus of claim 33 wherein said heart failure indicator is a sum of magnitudes of components of said flow signal in a sub-range of frequencies in said range.

35. The apparatus of claim 31 wherein said frequency analysis of said flow signal is performed with data sampled from a measure of ventilation derived from said flow signal.

36. The apparatus of claim

Assignees

• ResMed Pty Ltd

Inventors

• Ujhazy Anthony John
• Wright Jonathan Caldwell
• Richards Glenn
• Bassin David John
• Berthon-Jones Michael

Classifications

• A61B5/4836 Primary

  Diagnosis combined with treatment in closed-loop systems or methods (A61B5/0036 takes precedence) · CPC title

• A61M2205/3344

  Measuring or controlling pressure at the body treatment site · CPC title

• A61M2230/005

  Parameter used as control input for the apparatus · CPC title

• A61M2016/0021

  with a proportional output signal, e.g. from a thermistor · CPC title

• A61B5/0826

  Detecting or evaluating apnoea events (sleep apnoea A61B5/4818) · CPC title