Daytime/nighttime respiration rate monitoring

• US 7,530,956 B2
• Filed: 06/15/2007
• Issued: 05/12/2009
• Est. Priority Date: 06/15/2007
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Zhang, Yi, Hatlestad, John D., Lewicke, Aaron
• Primary Examiner(s): Nasser; Robert L
• Application Number:
  US11/820,002
• Publication Number:
  US 20080312541A1
• Time in Patent Office: 697 Days
• Field of Search: 600/484, 600/529
• US Class Current: 600/538
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/1116 Determining posture transitions
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

A device and method can monitor or trend a patient'"'"'s respiration rate measurements according to the time of day. The device, which may be implantable or external, collects and classifies respiration rate measurements over time. The trended information about particular classes of respiration rate measurements is then communicated to a remote external device, which in turn provides an indication of heart failure decompensation. Examples of classes of respiration rate measurements include a daily maximum respiration rate value, a daily minimum respiration rate value, a daily maximum respiration rate variability value, a daily minimum respiration rate variability value, and a daily central respiration rate value. These respiration rate measurements can be further classified into daytime or nighttime respiration rate measurements.

Claims

1. An apparatus comprising:

means for detecting a respiration signal from a subject;

means for determining respiration rate or interval measurements from the respiration signal;

means for classifying the respiration rate or interval measurements into at least one class of respiration rate or interval measurements and for associating a specified time of day with the at least one class;

means for trending at least one of;

(1) time of occurrence information about the classified respiration rate or interval measurements of a particular class of respiration rate or interval measurements, or (2) respiration rate or interval measurement information repeatedly, over a period of multiple days, during a specified one of a daytime subperiod or a nighttime subperiod, wherein the specified one of the daytime subperiod or the nighttime subperiod corresponds to the same specified time of day during each of the multiple days; and

means for providing a heart failure decompensation indication using the trended information.

2. The apparatus of claim 1, wherein the means for classifying the respiration rate or interval measurements into at least one class of respiration rate or interval measurements includes the following classes:

a daily maximum respiration rate value, a daily minimum respiration rate value, a daily maximum respiration rate variability value, a daily minimum respiration rate variability value, and a daily central respiration rate value.

3. The apparatus of claim 1, wherein the means for classifying the respiration rate or interval measurements into at least one class of respiration rate or interval measurements includes means for classifying the respiration rate or interval measurements as a specified one of daytime or nighttime respiration rate or interval measurements.

4. The apparatus of claim 3, comprising:

means for collecting the specified one of the daytime or nighttime respiration rate or interval measurements;

means for performing a statistical analysis on the collected respiration rate or interval measurements; and

means for providing the heart failure decompensation indication using a result of the statistical analysis.

5. The apparatus of claim 4, comprising means for providing the heart failure decompensation indication by detecting a change over time in a measure of centrality of the collected respiration rate or interval measurements.

6. The apparatus of claim 4, comprising means for providing the heart failure decompensation indication by detecting a change over time in a measure of spread or variance of the collected respiration rate or interval measurements.

7. The method of claim 1, wherein the means for trending information about the classified respiration rate or interval measurements comprises trending information about a time associated with the particular class of respiration rate or interval measurements.

8. An apparatus comprising:

a respiration sensor, configured to detect a respiration signal from a subject;

a respiration rate or interval measurement detector circuit, coupled to the respiration sensor, the respiration rate or interval measurement detector circuit configured to determine respiration rate or interval measurements from the respiration signal;

a processor circuit, comprising;

a respiration rate or interval measurement classifier circuit, configured to classify the respiration rate or interval measurements into at least one class of respiration rate or interval measurements, and configured to associate a specified time of day with the at least one class;

a trending circuit, configured to trend at least one of;

(1) time of occurrence information about the classified respiration rate or interval measurements, or (2) respiration rate or interval measurement information repeatedly, over a period of multiple days, during a specified one of a daytime subperiod or a nighttime subperiod, wherein the specified one of the daytime subperiod or the nighttime subperiod corresponds to the same specified time of day during each of the multiple days; and

an indicator circuit, configured to provide a heart failure decompensation indication using the trended information.

9. The apparatus of claim 8, wherein the respiration rate or interval measurement classifier unit classifies respiration rate or interval measurements into at least one of the following respiration rate or interval measurement classes:

a daily maximum respiration rate value, a daily minimum respiration rate value, a daily maximum respiration rate variability value, a daily minimum respiration rate variability value, and a daily central respiration rate value.

10. The apparatus of claim 8, wherein the respiration rate or interval measurement classifier circuit includes a clock circuit that is configured to classify the respiration rate or interval measurements according to the time of day.

11. The apparatus of claim 10, comprising:

a data centrality measurement circuit, configured to compute a measure of centrality of the specified one of the daytime respiration rate or interval measurements or nighttime respiration rate or interval measurements, and wherein the trending circuit is configured to trend the measure of centrality of the specified one of the nighttime or daytime respiration rate or interval measurements over a period of time;

a data comparator circuit, coupled to the data centrality measurement circuit, the data comparator circuit configured to detect a change in the measure of centrality of the specified one of the nighttime or daytime respiration rate or interval measurements over the period of time; and

wherein the indicator circuit is configured to provide the heart failure decompensation indication using the change in the measure of centrality of the specified one of the nighttime or daytime respiration rate or interval measurements over the period of time.

12. The apparatus of claim 10, comprising:

a data aggregation circuit, configured to aggregate the specified one of the nighttime or daytime respiration rate or interval measurements;

a statistical analysis circuit, coupled to the data aggregation circuit, the statistical analysis circuit configured to perform a statistical analysis on the aggregated specified one of the nighttime or daytime respiration rate or interval measurements; and

wherein the indicator circuit is configured to provide the heart failure decompensation indication using a result of the statistical analysis.

13. The apparatus of claim 12, wherein the indicator circuit is configured to provide the heart failure decompensation indication by detecting a change over time in a measure of centrality of the specified one of the nighttime or daytime respiration rate or interval measurements.

14. The apparatus of claim 12, wherein the indicator circuit is configured to provide the heart failure decompensation indication by detecting a change over time in a measure of spread or variance of the specified one of the nighttime or daytime respiration rate or interval measurements.

15. The apparatus of claim 8, wherein the trending circuit comprises trending information about a time associated with the particular class of respiration rate or interval measurements.

16. The apparatus of claim 10, comprising:

an integrator or lowpass filter, configured to integrate or otherwise lowpass filter the specified one of the nighttime or daytime respiration rate or interval measurements to obtain lowpass filtered respiration rate or interval measurements;

a data comparator circuit, coupled to the integrator or lowpass filter, the data comparator circuit configured to detect a change in the one of the lowpass filtered respiration rate or interval measurements over a period of time; and

wherein the indicator circuit is configured to provide the heart failure decompensation indication using the detected change in the lowpass filtered respiration rate or interval measurements.

17. The apparatus of claim 10, comprising:

a histogram memory, configured to store a histogram of the specified one of the nighttime or daytime respiration rate or interval measurements, wherein the histogram is configured to be updated over time;

a histogram memory, configured to store a histogram of the successive differences in the specified one of the nighttime or daytime respiration rate or interval measurements, wherein the histogram is configured to be updated over time;

a data comparator circuit, coupled to the histogram memories, the data comparator circuit configured to detect a change in the histogram over time; and

wherein the indicator circuit is configured to provide the heart failure decompensation indication using the detected change in the histograms.