Method and system for verifying the integrity of normal sinus rhythm templates

• US 6,996,434 B2
• Filed: 08/02/2001
• Issued: 02/07/2006
• Est. Priority Date: 03/12/1999
• Status: Expired due to Term

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Marcovecchio, Alan F., Hsu, William
• Primary Examiner(s): Bockelman, Mark
• Application Number:
  US09/921,348
• Publication Number:
  US 20020049474A1
• Time in Patent Office: 1,650 Days
• Field of Search: 600/513, 600/509
• US Class Current: 600/509
• CPC Class Codes: A61B 5/35 by template matching

Abstract

A method and system for verifying the integrity of normal sinus rhythm (NSR) templates and updating the NSR template after selected time intervals. At selected time intervals after establishing a NSR template, cardiac complexes are sensed and values for one or more cardiac parameters are measured. The values of the cardiac parameters are compared to predetermined value ranges for NSR cardiac complexes. When the values of the cardiac parameters fall within the predetermined value ranges, values for the differences between the values of the cardiac parameters for the cardiac complexes and the values for the cardiac parameters of the NSR cardiac complexes are calculated. When the values of the differences are greater than one or more threshold values, the NSR template is updated as a function of the sensed cardiac complexes.

Claims

1. A method, comprising:

comparing one or more sensed cardiac complex parameter values to one or more predetermined cardiac complex parameter values;

determining whether the one or more sensed cardiac complex parameter values and the one or more predetermined cardiac complex parameter values have differences greater than a threshold; and

updating a normal sinus rhythm (NSR) template upon determining that the one or more sensed cardiac complex parameter values and the one or more predetermined cardiac complex parameter values have differences that are greater than the threshold.

2. The method of claim 1, further comprising retaining the NSR template upon determining that the one or more sensed cardiac complex parameter values and the one or more predetermined cardiac complex parameter values do not have differences that are greater than the threshold.

3. The method of claim 1, further comprising determining whether the one or more sensed cardiac complex parameter values are within one or more ranges of normal values prior to comparing the one or more sensed cardiac complex parameter values to the one or more predetermined cardiac complex parameter values, wherein the one or more sensed cardiac complex parameter values are compared upon determining that the one or more sensed cardiac complex parameter values are within the one or more ranges of normal values.

4. The method of claim 3, further comprising:

upon determining that the one or more sensed cardiac complex parameter values are not within the one or more ranges of normal values, determining whether a maximum number of attempts has been made to evaluate the one or more sensed cardiac complex parameter values; and

upon determining that the maximum number of attempts has been made, retaining the NSR template.

5. The method of claim 1, further comprising waiting a selected time period before comparing the one or more sensed cardiac complex parameter values to one or more predetermined cardiac complex parameter values and determining whether the one or more sensed cardiac complex parameter values and the one or more predetermined cardiac complex parameter values have differences greater than a threshold.

6. The method of claim 5, wherein comparing one or more sensed cardiac complex parameter values to one or more predetermined cardiac complex parameter values and determining whether the one or more sensed cardiac complex parameter values and the one or more predetermined cardiac complex parameter values have differences greater than a threshold are automatically performed after the selected time period.

7. The method of claim 1, wherein comparing one or more sensed cardiac complex parameter values and determining whether the one or more sensed cardiac complex parameter values and the one or more predetermined cardiac complex parameter values have differences greater than a threshold are performed after receiving a physician-initiated command.

8. The method of claim 1, wherein comparing one or more sensed cardiac complex parameter values to one or more predetermined cardiac complex parameter values includes comparing one or more sensed cardiac complex parameter values to one or more physician-programmed values.

9. The method of claim 1, wherein comparing one or more sensed cardiac complex parameter values to one or more predetermined cardiac complex parameter values includes comparing one or more sensed cardiac complex parameter values to one or more values derived from a current NSR template.

10. The method of claim 1, further comprising creating an initial NSR template which is updated when the sensed cardiac complex parameter values and the predetermined cardiac complex parameter values have differences that are greater than the threshold.

11. The method of claim 10, wherein creating an initial NSR template includes:

determining whether one or more sensed cardiac complex parameter values are within one or more ranges of normal parameter values; and

setting the initial NSR template based on the one or more sensed cardiac complex parameter values.

12. The method of claim 11, further comprising displaying a proposed NSR template, and determining whether the proposed NSR template is approved prior to setting the initial NSR template.

13. The method of claim 11, further comprising:

upon determining that the one or more sensed cardiac complex parameter values are not within one or more ranges of normal parameter values, determining whether a maximum number of attempts has been made to evaluate the one or more sensed cardiac complex parameter values; and

upon determining that a maximum number of attempts has been made, redefining one or more ranges of acceptable parameter values.

14. The method of claim 1, wherein updating a NSR template comprises setting an updated NSR template based on the sensed cardiac complex parameter values.

15. The method of claim 14, further comprising displaying a proposed NSR template, and determining whether the proposed NSR template is approved prior to setting the updated NSR template.

16. A method, comprising:

creating a normal sinus rhythm (NSR) template;

determining whether sensed cardiac complex parameter values are within a range of normal values;

upon determining that the sensed cardiac complex parameter values are within a range of normal values, comparing the sensed cardiac complex parameter values to predetermined cardiac complex parameter values;

determining whether the sensed cardiac complex parameter values and the predetermined cardiac complex parameter values have differences greater than a threshold; and

updating the NSR template upon determining that the sensed cardiac complex parameter values and the predetermined cardiac complex parameter values have differences that are greater than the threshold.

17. The method of claim 16, further comprising:

upon determining that the sensed cardiac complex parameter values are not within a range of normal values, determining whether a maximum number of attempts has been made to evaluate the sensed cardiac complex parameter values; and

upon determining that the maximum number of attempts has been made, retaining the NSR template.

18. The method of claim 16, further comprising waiting a selected time period before comparing sensed cardiac complex parameter values to predetermined cardiac complex parameter values and determining whether the sensed cardiac complex parameter values and the predetermined cardiac complex parameter values have differences greater than a threshold.

19. The method of claim 18, wherein comparing sensed cardiac complex parameter values to predetermined cardiac complex parameter values and determining whether the sensed cardiac complex parameter values and the predetermined cardiac complex parameter values have differences greater than a threshold are automatically performed after the selected time period.

20. The method of claim 18, wherein comparing sensed cardiac complex parameter values to predetermined cardiac complex parameter values and determining whether the sensed cardiac complex parameter values and the predetermined cardiac complex parameter values have differences greater than a threshold are performed after receiving a physician-initiated command.

21. The method of claim 16, wherein creating a NSR template includes:

determining whether sensed cardiac complex parameter values are within a range of normal parameter values;

displaying a proposed NSR template based on the sensed cardiac complex parameter values;

determining whether the proposed NSR template is approved; and

setting the proposed NSR template as the NSR template.

22. The method of claim 16, wherein updating the NSR template upon determining that the sensed cardiac complex parameter values and the predetermined cardiac complex parameter values have differences that are greater than the threshold includes:

displaying a proposed updated NSR template;

determining whether the proposed updated NSR template is approved; and

upon determining that the proposed updated NSR template is approved, setting the proposed updated NSR template an updated NSR template.

23. The method of claim 16, wherein comparing the sensed cardiac complex parameter values to predetermined cardiac complex parameter values includes comparing sensed cardiac complex parameter values to physician-programmed values.

24. The method of claim 16, wherein comparing the sensed cardiac complex parameter values to predetermined cardiac complex parameter values includes comparing sensed cardiac complex parameter values to values derived from the NSR template.