Methods and systems for monitoring respiration

• US 6,918,878 B2
• Filed: 06/13/2003
• Issued: 07/19/2005
• Est. Priority Date: 06/13/2003
• Status: Expired due to Fees

• Current Assignee: GE Medical Systems Information Technologies Incorporated (General Electric Company)
• Original Assignee: GE Medical Systems Information Technologies Incorporated (General Electric Company)
• Inventors: Brodnick, Donald E.
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US10/460,972
• Publication Number:
  US 20040254481A1
• Time in Patent Office: 767 Days
• Field of Search: 600/528, 600529-538, 600/586
• US Class Current: 600/483
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 7/04 Electric stethoscopes microphones, acoustic transducers therefor H04R

Abstract

A method for determining respiration rate in a patient can include various parts. The respiration rate can be determined by measuring the heart'"'"'s S2 split. The S2 split can be identified by observing the timing of the heart sounds. Other respiration related information, such as respiration phase and the occurrence of apnea, can be identified as well. A respiration monitor of this type may be useful for monitoring sub-acute patients, and outpatients. A sensor for the respiration monitor and an electrode for an ECG monitor may be combined into a single probe.

Claims

1. A method comprising:

obtaining heart sounds from a patient wherein the heart sounds are used to determine a duration of an S2 split; and

determining respiration rate based on timing of the heart sounds and the duration of the S2 split;

determining heart rate; and

wherein determining respiration rate further comprises using the heart rate as a reference to identify the S2 split.

2. The method of claim 1, wherein obtaining heart sounds comprises inputting signals from an acoustic sensor positioned to detect heart sounds.

3. The method of claim 2, wherein the acoustic sensor from which signals are input is positioned at the left or right border of the sternum at about ICS-4.

4. The method of claim 2, the acoustic sensor is a piezo acoustic sensor.

5. The method of claim 1, further comprising determining heart rate based on the heart sounds.

6. The method of claim 5, further comprising determining heart rate variability based on the heart rate determination.

7. The method of claim 1, further comprising identifying a heart condition based on the heart sounds.

8. The method of claim 1, further comprising determining respiration rate using a technique not involving the use of heart sounds.

9. The method of claim 1, further comprising displaying information relating to the respiration rate.

10. The method of claim 1, further comprising transferring information relating to respiration rate across a network.

11. The method of claim 1, further comprising generating a bill based on use of a monitoring system used to determine respiration rate.

12. The method of claim 1, further comprising identifying patient conditions based on the determination of the respiration rate.

13. The method of claim 1, further comprising determining respiration rate based on changes in amplitude of the heart sounds.

14. The method of claim 1, wherein determining the respiration rate comprises identifying a pattern of a plurality of S2 split durations.

15. A method for determining respiration rate in a patient having an S2 split that depends on respiration phase, comprising:

identifying a duration of an S2 split; and

determining respiration rate based on the duration of the S2 split

determining heart rate; and

determining respiration rate further comprising using the heart rate as a reference to identify the S2 split.

16. The method of claim 15, wherein the duration of the S2 split is identified by detecting sounds caused by the closing of the aortic valve and the pulmonary valve.

17. The method of claim 15, wherein determining respiration rate comprises determining a rate based on a patient'"'"'s characteristics.

18. The method of claim 15, further comprising displaying information relating to the respiration rate which has been determined.

19. The method of claim 18, wherein the information displayed includes the respiration rate.

20. The method of claim 15, further comprising generating an alarm based on durations of a plurality of S2 splits.

21. The method of claim 15, further comprising generating information for a patient record based on the determination of the respiration rate.

22. The method of claim 15, further comprising identifying patient conditions based on the determination of the respiration rate.

23. The method of claim 15, wherein determining the respiration rate comprises identifying a pattern of a plurality of S2 split durations.

24. The method of claim 15, further comprising identifying heart related conditions.

25. A method comprising:

determining respiration rate based on timing of heart sounds of a patient;

identifying occurrence of apnea based on the heart sounds; and

identifying the type of apnea that has occurred.

26. The method of claim 25, further comprising determining heart rate based on the heart sounds.

27. The method of claim 25, further comprising generating information for a patient record based on the determination of the respiration rate.

28. The method of claim 25, further comprising displaying information relating to the apnea event which has been identified.

29. The method of claim 25, further comprising generating an alarm based on the respiration rate.

30. A medical monitoring system comprising:

a data input configured to receive signals from a heart acoustic sensor, wherein the signals include heart sounds used to determine a duration of an S2 split; and

a processing circuit configured to determine respiration rate based on the heart sounds and the duration of the S2 input from the heart acoustic sensor, the processing circuit further configured to determine heart rate, wherein determining the respiration rate includes using the heart rate as a reference to identify the S2 split.

31. The system of claim 30, further comprising a heart acoustic sensor.

32. The system of claim 31, wherein the heart acoustic sensor comprises a piezo acoustic sensor.

33. The system of claim 31, wherein the heart acoustic sensor further comprises an ECG electrode.

34. The system of claim 33, further comprising a processing circuit configured to process ECG signals.

35. The system of claim 34, wherein the processing circuit configured to process ECG signals is part of the same circuit as the processing circuit configured to determine respiration rate.

36. The system of claim 30, wherein the processing circuit comprises analog band pass filter circuitry configured to produce a filtered heart sound signal based on a signal received from the data input and a microprocessor configured to determine respiration rate based on the filtered heart sound signal.

37. The system of claim 36, wherein the band pass filter is configured to allow signals from about 100 Hz to about 500 HZ to pass.

38. The system of claim 30, wherein the processing circuit comprises a microprocessor configured to produce a filtered heart sound signal based on a signal received from the data input and configured to determine respiration rate based on the filtered heart sound signal.

39. The system of claim 30, wherein the processing circuit comprises a data storage medium and control circuitry configured to facilitate storage of data which has been inputted from the data input.