Detection of congestion from monitoring patient response to a recumbent position

• US 7,226,422 B2
• Filed: 10/09/2002
• Issued: 06/05/2007
• 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: Zhu, Qingsheng, Hatlestsad, John, Stahmann, Jeffrey E
• Primary Examiner(s): Nasser; Robert L.
• Application Number:
  US10/267,982
• Publication Number:
  US 20040073128A1
• Time in Patent Office: 1,700 Days
• Field of Search: None
• US Class Current: 600/534
• 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 determining whether a patient is suffering from congestion, 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;

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

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; and

in response to the difference between the first respiration pattern and the second respiration pattern determining whether the patient is suffering from congestion.

2. 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.

3. The method of claim 2, further comprising detecting the reclination of the torso with a tilt switch.

4. The method of claim 2, further comprising detecting the reclination of the torso with an accelerometer.

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

6. The method of claim 1, 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.

7. The method of claim 1, 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.

8. The method of claim 1, 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 for the first respiration pattern to a combination of tidal volume of respiration and respiration rate for the second respiration pattern.

9. The method of claim 1, 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.

10. 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.

11. A system for determining whether a patient is suffering from congestion 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 pattern data from the respiration signal; and

a processing device that performs the following steps;

monitoring the respiration pattern data and the reclination data,

determining whether the patient is in a recumbent position by comparing the reclination data to data representative of a reclination threshold,

associating the respiration pattern data obtained at a point in time with the reclination data obtained at the point in time

comparing the respiration pattern data obtained when the patient is in a recumbent position to the respiration pattern data obtained with the patient is in a non-recumbent position to detect whether a difference is present between the respiration patterns associated with recumbent and non-recumbent positions; and

in response to differences between the respiration patterns associated with recumbent and non-recumbent positions determining whether the patient is suffering from congestion.

12. The system of claim 11, wherein the reclination sensor is a tilt switch.

13. The system of claim 11, wherein the reclination sensor is an accelerometer.

14. The system of claim 11, wherein the respiration sensor produces a respiration signal in response to a change in trans-thoracic impedance.

15. The system of claim 11, 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.

16. The system of claim 11, 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.

17. The system of claim 11, 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.

18. The system of claim 11, further comprising a communication device for transmitting the association of respiratory data with reclination data to another system.

19. A system for determining whether a patient is suffering from congestion, 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

means for 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; and

in response to the difference between the first respiration pattern and the second respiration pattern means for determining whether the patient is suffering from congestion.

20. The system of claim 19, wherein the means for detecting whether the patient is in a recumbent position comprises a tilt switch.

21. The system of claim 19, wherein the means for detecting whether the patient is in a recumbent position comprises an accelerometer.

22. The system of claim 19, wherein the means for measuring a first and second respiration pattern comprises a trans-thoracic impedance sensor.

23. The system of claim 19, wherein means for comparing comprises a microprocessor.

24. The system of claim 19, wherein means for comparing detects a difference in respiratory rate between the first and second respiration patterns.

25. The system of claim 19, wherein means for comparing detects a difference in tidal volume of respiration between the first and second respiration patterns.

26. The system of claim 19, further comprising a means for communicating the first and second respiration patterns to another system.