Detection of congestion from monitoring patient response to a recumbent position

• US 20040073128A1
• Filed: 10/09/2002
• Published: 04/15/2004
• Est. Priority Date: 10/09/2002
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Stahmann, Jeffrey E., Zhu, Qingsheng, Hatlestad, John
• Granted Patent: US 7,226,422 B2
• Time in Patent Office: Days
• US Class Current: 600/533
• CPC Class Codes: A61B 5/0809 by impedance pneumography
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/1071 measuring angles, e.g. using goniometers A61B5/1123 takes precedence
• CPC Class Codes: A61B 5/1116 Determining posture transitions
• CPC Class Codes: A61B 5/1135 by monitoring thoracic expansion
• CPC Class Codes: A61B 5/4806 Sleep evaluation A61B5/4821 takes precedence; devices for inducing sleep A61M21/02
• CPC Class Codes: A61B 5/6831 Straps, bands or harnesses
• CPC Class Codes: A61B 5/6846 specially adapted to be brought in contact with an internal body part, i.e. invasive
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61N 1/36542 controlled by body motion, e.g. acceleration
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

Systems and methods obtain information that allows detection of whether a patient suffers from congestion by monitoring a response of the patient to a recumbent position of the patient'"'"'s body. The patient may be monitored to determine a respiration pattern for a non-recumbent position such as standing and a respiration pattern for a recumbent position such as lying down. The two patterns may be compared, either by a processing device or a physician, to determine a difference in the two respiration patterns. Furthermore, the congestion may be inferred from detecting an amount of time that the patient spends in a recumbent position of from detecting the recumbent angle that the patient obtains, either of which is presumed to indicate whether a recumbent position presents discomfort to the patient due to the presence of congestion.

Claims

1. A method of obtaining information related to congestion of a patient, comprising:

detecting whether the patient is in a recumbent position;

when the patient is not in the recumbent position, monitoring the respiration of the patient to detect a first respiration pattern; and

when the patient is in the recumbent position, monitoring the respiration of the patient to detect a second respiration pattern;

2. The method of claim 1, further comprising:

comparing the first respiration pattern to the second respiration pattern to detect whether a difference is present between the first respiration pattern and the second respiration pattern.

3. The method of claim 1, wherein detecting whether the patient is in the recumbent position comprises comparing a reclination of a torso of the patient to a threshold.

4. The method of claim 3, further comprising detecting the reclination of the torso with a tilt switch.

5. The method of claim 3, further comprising detecting the reclination of the torso with an accelerometer.

6. The method of claim 1, wherein monitoring the respiration comprises monitoring trans-thoracic impedance.

7. The method of claim 2, wherein comparing the first respiration pattern to the second respiration pattern to detect whether a difference is present comprises comparing a rate of respiration of the first pattern to a rate of respiration of the second pattern.

8. The method of claim 2, wherein comparing the first respiration pattern to the second respiration pattern to detect whether a difference is present comprises comparing a tidal volume of respiration of the first respiration pattern to a tidal volume of respiration of the second respiration pattern.

9. The method of claim 2, wherein comparing the first respiration pattern to the second respiration pattern to detect whether a difference is present comprises comparing a combination of tidal volume of respiration and respiration rate from the first respiration pattern to a combination of tidal volume of respiration and respiration rate for the second respiration pattern.

10. The method of claim 2, wherein comparing the first respiration pattern to the second respiration pattern to detect whether a difference is present comprises comparing an inspiratory time the first respiration pattern to an inspiratory time for the second respiration pattern and comparing an expiratory time the first respiration pattern to an expiratory time for the second respiration pattern.

11. The method of claim 1, further comprising:

detecting over multiple periods whether the patient is in a recumbent position;

when the patient is not in the recumbent position during each period, monitoring the respiration of the patient to detect a first respiration pattern for a current period; and

when the patient is in the recumbent position during each period, monitoring the respiration of the patient to detect a second respiration pattern for a current period;

comparing the first respiration pattern to the second respiration pattern for each period to detect whether a difference is present between the first respiration pattern and the second respiration pattern for each period; and

analyzing the comparison for each period to determine a trend.

12. A method of obtaining information related to congestion of a patient, comprising:

continuously monitoring a patient during a period of time with at least one device, wherein the at least one device monitors time while detecting whether the patient is in a recumbent position to compute the amount of time during the period that the patient is in the recumbent position.

13. The method of claim 12, further comprising:

comparing the amount of time that the patient is in a recumbent position to a time threshold, wherein the time threshold is related to a congestive condition.

14. The method of claim 12, wherein continuously monitoring the patient comprises detecting whether a reclination of the torso of the patient exceeds a reclination threshold

15. The method of claim 14, wherein detecting whether a reclination exceeds a reclination threshold comprises obtaining the reclination by using a tilt switch of the at least one device.

16. The method of claim 14, wherein detecting whether a reclination exceeds a reclination threshold comprises obtaining the reclination by using an accelerometer of the at least one device.

17. The method of claim 12, further comprising:

continuously monitoring the patient over multiple periods of time to determine an amount of time during each period that the patient is in a recumbent position, and

analyzing the amount of time for each period to determine a trend.

18. A method of obtaining information related to congestion of a patient, comprising:

continuously monitoring a recumbent angle of the patient during a period of time; and

comparing the recumbent angle of the patient to a recumbent angle threshold, wherein the recumbent angle threshold is related to a congestive condition.

19. The method of claim 18, wherein continuously monitoring a recumbent angle of the patient comprises obtaining the recumbent angle by using an accelerometer.

20. The method of claim 18, further comprising:

continuously monitoring the recumbent angle of the patient over multiple periods of time to determine recumbent angle values for each period; and

analyzing the recumbent angle values for each period to determine a trend.

21. The method of claim 18, wherein monitoring the recumbent angle comprises obtaining recumbent angle values during the period and obtaining the maximum recumbent angle value for the period.

22. The method of claim 18, wherein monitoring the recumbent angle comprises obtaining recumbent angle values during the period and obtaining an average of the recumbent angle values for the period.

23. A system for obtaining information related to congestion of a patient, comprising:

a reclination sensor that produces a reclination signal indicative of the reclination of the patient;

detection circuitry that produces reclination data from the reclination signal;

a respiration sensor that produces a respiration signal indicative of respiration patterns of the patient;

respiration circuitry that produces respiration data from the respiration signal; and

a processing device that monitors the respiration pattern data and the reclination data, detects whether the patient is in a recumbent position by comparing the reclination data to a threshold, and associates the respiration pattern data obtained at a point in time with the reclination data obtained at the point in time.

24. The system of claim 23, wherein the processing device compares the respiration pattern data taken during a non-recumbent position as indicated by the associated reclination data to the respiration pattern data taken during a recumbent position as indicated by the associated reclination data to detect whether a difference exists.

25. The system of claim 23, wherein the reclination sensor is a tilt switch.

26. The system of claim 23, wherein the reclination sensor is an accelerometer.

27. The system of claim 23, wherein the respiration sensor produces a respiration signal in response to a change in trans-thoracic impedance.

28. The system of claim 24, wherein the processing device compares the respiration pattern data taken during a non-recumbent position to respiration data taken during a recumbent position to detect whether a difference in respiration rate exists.

29. The system of claim 24, wherein the processing device compares the respiration pattern data taken during a non-recumbent position to respiration data taken during a recumbent position to detect whether a difference in tidal volume of respiration exists.

30. The system of claim 24, wherein the processing device compares the respiration pattern data taken during a non-recumbent position to respiration data taken during a recumbent position to detect whether a difference in a ratio of respiration rate to tidal volume of respiration exists.

31. The system of claim 23, further comprising a communication device for transmitting the association of respiratory data with reclination data to another system

32. A system for obtaining information related to congestion of a patient, comprising:

a reclination sensor that produces a signal indicative of the reclination of the patient;

reclination circuitry that produces reclination data from the reclination signal;

a clock that produces timing signals;

a memory; and

a processing device that communicates with the reclination circuitry and clock to determine from the reclination data and timing signals an amount of time that the patient is in a recumbent position and that stores the amount of time in memory.

33. The system of claim 32, wherein the processing device compares the amount of time stored in memory to a time threshold related to a congestive condition and stores a result of the comparison in memory.

34. The system of claim 32, wherein the reclination sensor is a tilt switch.

35. The system of claim 32, wherein the reclination sensor is an accelerometer.

36. The system of claim 32, further comprising a communication device that transmits the amount of time stored in memory to another system.

39. The system of claim 36, further comprising a communication device for transmitting the recumbent angle to another system.

37. A system for obtaining information related to congestion of a patient, comprising:

a reclination sensor that produces a signal indicative of the reclination of the patient;

reclination circuitry that produces reclination data from the reclination signal; and

a processing device that communicates with the reclination circuitry to determining a recumbent angle of the patient from the reclination data and that compares the recumbent angle to a recumbent angle threshold that is related to a congestive condition.

38. The system of claim 37, wherein the reclination sensor is an accelerometer.

40. A system for obtaining information related to congestion of a patient, comprising:

means for detecting whether the patient is in a recumbent position, and

means for measuring a first respiration pattern while the patient is in a recumbent position and for measuring a second respiration pattern while the patient is in a non-recumbent position.

41. The system of claim 40, further comprising means for comparing the first respiration pattern to the second respiration pattern to detect a difference.

42. The system of claim 40, wherein the means for detecting whether the patient is in a recumbent position comprises a tilt switch.

43. The system of claim 40, wherein the means for detecting whether the patient is in a recumbent position comprises an accelerometer.

44. The system of claim 40, wherein the means for measuring a first and second respiration pattern comprises a trans-thoracic impedance sensor.

45. The system of claim 41, wherein means for comparing comprises a microprocessor.

46. The system of claim 41, wherein means for comparing detects a difference in respiratory rate between the first and second respiration patterns.

47. The system of claim 41, wherein means for comparing detects a difference in tidal volume of respiration between the first and second respiration patterns.

48. The system of claim 41, further comprising a means for communicating the first and second respiration patterns to another system.

49. A system for obtaining information related to congestion of a patient, comprising:

means for tracking time;

means for detecting whether the patient is in a recumbent position; and

means for storing the amount of time that the patient is in a recumbent position.

50. The system of claim 49, further comprising:

means for comparing the amount of time that the patient is in a recumbent position to a time threshold, wherein the time threshold is related to a congestive condition.

51. The system of claim 49, wherein the means for detecting comprises a tilt switch and a clock.

52. The system of claim 50, wherein the means for comparing comprises a microprocessor.

53. The system of claim 49, further comprising means for communicating the stored amount of time to another system.

54. A system for obtaining information related to congestion of a patient, comprising:

means for determining a recumbent angle of the patient; and

means for comparing the recumbent angle to a recumbent angle threshold that is related to a congestive condition.

55. The system of claim 54, wherein the means for determining a recumbent angle is an accelerometer.

56. The system of claim 54, further comprising means for transmitting the recumbent angle to another system.