System and method for reconstructing cardiac activation information

1. A method of reconstructing cardiac activation information, the method comprising:

processing, by a computing device, an analysis cardiac signal and a reference cardiac signal to determine a first point of change in a derivative of the analysis cardiac signal with respect to a derivative of the reference cardiac signal, the derivative of the analysis cardiac signal and the derivative of the reference cardiac signal being selected from zero, first and second order derivative;

processing, by the computing device, the analysis cardiac signal and the reference cardiac signal to determine a second point of change in a different derivative of the analysis cardiac signal with respect to a different derivative of the reference cardiac signal, the different derivative of the analysis cardiac signal and the different derivative of the reference cardiac signal being selected from zero, first and second order derivative; and

assigning an activation onset time in the analysis cardiac signal at a point based on a mathematical association of the first point of change and the second point of change to define cardiac activation indicating a beat in the analysis cardiac signal.

2. The method of claim 1 , wherein the mathematical association is an average of the first point of change and the second point of change representing a majority from reference cardiac signals processed in relation to the analysis cardiac signal.

3. The method of claim 2 , wherein the first point of change and the second point of change are within a predetermined time interval of each other.

4. The method of claim 2 , wherein the predetermined time interval is ±5 ms.

5. The method of claim 1 , wherein the mathematical association is an average of the first point of change and the second point of change representing a plurality from reference cardiac signals processed in relation to the analysis cardiac signal.

6. The method of claim 5 , wherein the first point of change and the second point of change are within a predetermined time interval of each other.

7. The method of claim 6 , wherein the predetermined time interval is ±5 ms.

8. The method of claim 1 , wherein the mathematical association is a selection of one of the first point of change and the second point of change.

9. The method of claim 8 , wherein the selection comprises:

computing a first difference value of the first point of change minus a first threshold that is associated with the first point of change;

computing a second difference value of the second point of change minus a second threshold that is associated with the second point of change; and

selecting one of the first point of change and the second point of change based on a highest difference value among the first difference value and the second difference value.

10. The method of claim 8 , wherein the selection is based on a highest order derivative that is above an associated threshold.

11. The method of claim 1 , wherein the first point of change and the second point of change are determined at about the same time point for the analysis cardiac signal and the reference cardiac signal.

12. The method of claim 1 , wherein the first point of change and the second point of change are determined from one or more of slope, amplitude, timing and shape for the analysis cardiac signal and the reference cardiac signal.

13. The method of claim 1 , wherein determination of the first point of change comprises:

forming a composite cardiac signal from the analysis cardiac signal and the reference cardiac signal;

determining ratio values at a plurality of points in the analysis cardiac signal, each ratio value representing a difference between the derivative of the reference cardiac signal and a derivative of the composite cardiac signal to a difference between the derivative of the analysis cardiac signal and the derivative of the composite cardiac signal, the derivative of the composite cardiac signal being one of zero, first and second order derivative; and

selecting as the first point of change in the analysis cardiac signal a point having a largest ratio value from the determined ratio values.

14. The method of claim 1 , wherein determination of the second point of change comprises:

forming a composite cardiac signal from the analysis cardiac signal and the reference cardiac signal;

determining ratio values at a plurality of points in the analysis cardiac signal, each ratio value representing a difference between the different derivative of the reference cardiac signal and a derivative of the composite cardiac signal to a difference between the different derivative of the analysis cardiac signal and the derivative of the composite cardiac signal, the derivative of the composite cardiac signal being one of zero, first and second order derivative; and

selecting as the second point of change in the analysis cardiac signal a point having a largest ratio value from the determined ratio values.

15. The method of claim 1 , wherein the first point of change and the second point of change at or below a noise level is associated with one or more signals from a heart, respiratory system, gastrointestinal tract, neurological system and electronic interference.

16. The method of claim 1 , further comprising performing processing and assigning to define multiple cardiac activations indicating beats in the analysis cardiac signal.

17. The method of claim 1 , further comprising iteratively selecting the analysis cardiac signal and the reference cardiac signal from a plurality of cardiac signals.

18. The method of claim 1 , further comprising:

iteratively selecting pairs of cardiac signals from a plurality of cardiac signals, each pair having an analysis cardiac signal and different reference cardiac signal;

performing processing and assigning for each of the pairs to define multiple cardiac activations associated indicating beats for the analysis cardiac signal in each of the pairs; and

reconstructing a cardiac activation pattern based on assigned activation onset times of cardiac activations from the plurality of cardiac signals to indicate a source of a cardiac rhythm disorder.

19. A system to reconstruct cardiac activation information comprising:

at least one computing device configured to:

process an analysis cardiac signal and a reference cardiac signal to determine a first point of change in a derivative of the analysis cardiac signal with respect to a derivative of the reference cardiac signal, the derivative of the analysis cardiac signal and the derivative of the reference cardiac signal being selected from zero, first and second order derivative;

process the analysis cardiac signal and the reference cardiac signal to determine a second point of change in a different derivative of the analysis cardiac signal with respect to a different derivative of the reference cardiac signal, the different derivative of the analysis cardiac signal and the different derivative of the reference cardiac signal being selected from zero, first and second order derivative; and

assign an activation onset time in the analysis cardiac signal at a point based on a mathematical association of the first point of change and the second point of change to define cardiac activation indicating a beat in the analysis cardiac signal.

20. The system of claim 19 , wherein the mathematical association is an average of the first point of change and the second point of change representing a majority from reference cardiac signals processed in relation to the analysis cardiac signal.

21. The system of claim 20 , wherein the first point of change and the second point of change are within a predetermined time interval of each other.

22. The system of claim 21 , wherein the predetermined time interval is ±5 ms.

23. The system of claim 19 , wherein the mathematical association is an average of the first point of change and the second point of change representing a plurality from reference cardiac signals processed in relation to the analysis cardiac signal.

24. The system of claim 23 , wherein the first point of change and the second point of change are within a predetermined time interval of each other.

25. The system of claim 24 , wherein the predetermined time interval is ±5 ms.

26. The system of claim 19 , wherein the mathematical association is a selection of one of the first point of change and the second point of change.

27. The system of claim 26 , wherein at least one computing device is further configured to:

compute a first difference value of the first point of change minus a first threshold that is associated with the first point of change;

compute a second difference value of the second point of change minus a second threshold that is associated with the second point of change; and

select one of the first point of change and the second point of change based on a highest difference value among the first difference value and the second difference value.

28. The system of claim 26 , wherein the selection is based on a highest order derivative that is above an associated threshold.

29. The system of claim 19 , wherein the first point of change and the second point of change are determined at about the same time point for the analysis cardiac signal and the reference cardiac signal.

30. The system of claim 19 , wherein the first point of change and the second point of change are determined from one or more of slope, amplitude, timing and shape for the analysis cardiac signal and the reference cardiac signal.

31. The system of claim 19 , wherein at least one computing device is further configured to:

form a composite cardiac signal from the analysis cardiac signal and the reference cardiac signal;

determine ratio values at a plurality of points in the analysis cardiac signal, each ratio value representing a difference between the derivative of the reference cardiac signal and a derivative of the composite cardiac signal to a difference between the derivative of the analysis cardiac signal and the derivative of the composite cardiac signal, the derivative of the composite cardiac signal being one of zero, first and second order derivative; and

select as the first point of change in the analysis cardiac signal a point having a largest ratio value from the determined ratio values.

32. The system of claim 19 , wherein at least one computing device is further configured to:

form a composite cardiac signal from the analysis cardiac signal and the reference cardiac signal;

determine ratio values at a plurality of points in the analysis cardiac signal, each ratio value representing a difference between the different derivative of the reference cardiac signal and a derivative of the composite cardiac signal to a difference between the different derivative of the analysis cardiac signal and the derivative of the composite cardiac signal, the derivative of the composite cardiac signal being one of zero, first and second order derivative; and

select as the second point of change in the analysis cardiac signal a point having a largest ratio value from the determined ratio values.

33. The system of claim 19 , wherein the first point of change and the second point of change at or below a noise level is associated with one or more signals from a heart, respiratory system, gastrointestinal tract, neurological system and electronic interference.

34. The system of claim 19 , wherein at least one computing device is further configured to perform to perform processing and assigning to define multiple cardiac activations indicating beats in the analysis cardiac signal.

35. The system of claim 19 , wherein at least one computing device is further configured to iteratively select the analysis cardiac signal and the reference cardiac signal from a plurality of cardiac signals.

36. The system of claim 19 , wherein at least one computing device is further configured to:

iteratively select pairs of cardiac signals from a plurality of cardiac signals, each pair having an analysis cardiac signal and different reference cardiac signal;

perform processing and assigning for each of the pairs to define multiple cardiac activations associated indicating beats for the analysis cardiac signal in each of the pairs; and

reconstruct a cardiac activation pattern based on assigned activation onset times of cardiac activations from the plurality of cardiac signals to indicate a source of a cardiac rhythm disorder.

37. A method of treating a cardiac rhythm disorder, the method comprising:

iteratively accessing an analysis cardiac signal and a reference cardiac signal from a plurality of cardiac signals;

processing, by a computing device, the analysis cardiac signal and the reference cardiac signal to determine a first point of change in a derivative of the analysis cardiac signal with respect to a derivative of the reference cardiac signal, the derivative of the analysis cardiac signal and the derivative of the reference cardiac signal being selected from zero, first and second order derivative;

processing, by the computing device, the analysis cardiac signal and the reference cardiac signal to determine a second point of change in a different derivative of the analysis cardiac signal with respect to a different derivative of the reference cardiac signal above a second threshold, the different derivative of the analysis cardiac signal and the different derivative of the reference cardiac signal being selected from zero, first and second order derivative;

assigning activation onset times in the analysis cardiac signal at points based on a mathematical association of first points of change and second points of change to define cardiac activations indicating beats in the analysis cardiac signal;

reconstructing a cardiac activation pattern based on the assigned activation onset times to indicate a source of the cardiac rhythm disorder; and

treating cardiac tissue at the source to suppress or eliminate the cardiac rhythm disorder.