DETECTING OR VALIDATING A DETECTION OF A STATE CHANGE FROM A TEMPLATE OF HEART RATE DERIVATIVE SHAPE OR HEART BEAT WAVE COMPLEX

• US 20120071775A1
• Filed: 09/20/2010
• Published: 03/22/2012
• Est. Priority Date: 09/16/2010
• Status: Active Grant

• Current Assignee: Flint Hills Scientific, LLC
• Original Assignee: Flint Hills Scientific, LLC
• Inventors: Osorio, Ivan, Frei, Mark
• Granted Patent: US 8,452,387 B2
• Time in Patent Office: Days
• US Class Current: 600/515
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• CPC Class Codes: A61B 5/33 specially adapted for cooperation with other devices
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/35 by template matching
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61B 5/364 Detecting abnormal ECG interval, e.g. extrasystoles, ectopic heartbeats
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61N 1/36053 adapted for vagal stimulation A61N1/36114 takes precedence
• CPC Class Codes: A61N 1/36064 Epilepsy

Abstract

Methods, systems, and apparatus for detecting and/or validating a detection of a state change by matching the shape of one or more of an cardiac data series, a heart rate variability data series, or at least a portion of a heart beat complex, derived from cardiac data, to an appropriate template.

Claims

1. A computer readable program storage unit encoded with instructions that, when executed by a computer, perform a method for indicating an occurrence of a state change, comprising:

obtaining data relating to at least a portion of a heart beat complex from a patient;

comparing said at least said portion of said heart beat complex with a corresponding portion of a first reference heart beat complex template of said patient; and

,

indicating an occurrence of a state change based upon a determination that said heart beat complex fails to match said first reference heart beat complex template.

2. The computer readable program storage unit of claim 1, wherein said portion of said heart beat complex comprises at least one of an amplitude of a P wave, a polarity of a P wave, at least one of an amplitude of an R wave, a polarity of a Q wave, a polarity of an R wave, an amplitude of an S wave, a polarity of an S wave, an amplitude of a T wave, a polarity of a T wave, an area under the curve of a P wave, an area under the curve of a Q wave, an area under the curve of an R wave, an area under the curve of an S wave, an area under the curve of a T wave, a width of a P wave, a with of a Q wave, a width of an n R wave, a width of an S wave, a width of a T wave, a morphology of a P wave, a morphology of a Q wave, a morphology of an R wave, a morphology of a T wave, a magnitude of a change in the distance from a P wave to a Q wave, a magnitude of a change in the distance from a P wave to an R wave, a magnitude of a change in the distance from a Q wave to an R wave, a magnitude of a change in the distance from an R wave to an S wave, a magnitude of a change in the distance from an R wave to a T wave, a magnitude of a change in the distance from an S wave to a T wave, a magnitude of an S-T segment elevation, a magnitude of an S-T segment depression, a magnitude of a Q-T segment elevation, a magnitude of a Q-T segment depression, a P-R interval, an R-S interval, an S-T interval, an R-T interval, and a Q-T interval.

3. The computer readable program storage unit of claim 1, wherein said first reference heart beat complex template comprises at least a first matched filter.

4. The computer readable program storage unit of claim 1, wherein said comparing further comprises comparing said at least a portion of said first heart beat complex with a corresponding portion of a second reference heart beat complex template of said patient, and wherein said indicating is based upon a determination that said first heart beat complex fails to match at least one of said first reference heart beat complex template and said second reference heart beat complex template.

5. The computer readable program storage unit of claim 4, wherein said second reference heart beat complex template comprises a state change complex template, and wherein said indicating said occurrence of said state change is based upon both said determination that said first heart beat complex fails to match said first reference heart beat complex template and a determination that said first heart beat complex matches said state change complex template.

6. The computer readable program storage unit of claim 1, wherein said first reference heart beat complex template is selected from a normal template or an abnormal template.

7. The computer readable program storage unit of claim 3, wherein said first heart beat complex fails to match said first reference heart beat complex template if a first matched filter output for said first heart beat complex is less than a first matched filter threshold, or differs from a second matched filter threshold by at least a predetermined magnitude.

8. The computer readable program storage unit of claim 1, wherein said method further comprises:

identifying an occurrence of a state change prior to said comparing step and said indicating step, wherein said identifying is not based upon a determination that at least a portion of said first heart beat complex fails to match said first reference heart beat complex template;

and wherein said comparing and said indicating are performed in response to said identifying, to validate said identifying.

9. The computer readable program storage unit of claim 8, wherein said identifying comprises:

obtaining a time series of cardiac data from a patient;

determining a reference heart rate parameter from said cardiac data;

determining a heart rate derivative shape from said time series of cardiac data, wherein said heart rate derivative shape comprises at least one characteristic selected from a number of phases relative to said reference heart rate parameter, a number of extrema of said heart rate derivative, a number of directions of change of said heart rate derivative, an area under the curve of at least one phase, a number of positive phases, or a number of negative phases; and

,

identifying said occurrence of said state change based upon a determination that said heart rate derivative shape matches a state change template in said at least one characteristic.

10. The computer readable program storage unit of claim 9, wherein said heart rate derivative is selected from heart rate or heart rate variability.

11. The computer readable program storage unit of claim 9, wherein said identifying further comprises:

determining a second reference heart rate parameter; and

determining a second heart rate derivative shape from said time series of cardiac data, wherein said second heart rate derivative shape comprises at least one second characteristic selected from a number of phases relative to said reference heart rate parameter, a number of positive phases relative to said reference heart rate parameter, a number of negative phases relative to said reference heart rate parameter, a number of extrema of said second heart rate derivative, an area under the curve of at least one phase, or a number of directions of change of said second heart rate derivative;

wherein said identifying said occurrence of said state change is further based upon a determination that said second heart rate derivative shape matches a second state change template in said at least one second characteristic.

12. The computer readable program storage unit of claim 1, wherein said method further comprises:

validating an occurrence of a state change in response to said indicating, wherein said validating is not based upon a determination that at least a portion of a heart beat complex fails to match a first reference heart beat complex template.

13. The computer readable program storage unit of claim 12, wherein said validating comprises:

obtaining a time series of cardiac data from a patient;

determining a reference heart rate parameter from said cardiac data;

determining a heart rate derivative shape from said time series of cardiac data, wherein said heart rate derivative shape comprises at least one characteristic selected from a number of phases relative to said reference heart rate parameter, a number of extrema of said heart rate derivative, a number of directions of change of said heart rate derivative, a number of positive phases, or a number of negative phases; and

,

identifying said occurrence of said state change based upon a determination that said heart rate derivative shape matches a state change template in said at least one characteristic.

14. The computer readable program storage unit of claim 1, wherein said method further comprises:

obtaining a time series of data relating to a plurality of heart beat complexes from said patient, said obtaining occurring after said indicating;

comparing at least a portion of each of a sequential plurality of heart beat complexes with a corresponding portion of said first reference heart beat complex template; and

,

indicating said termination of said state change based upon a determination that at least one heart beat complex of said sequential plurality of heart beat complexes matches said first reference heart beat complex template, after said indicating an occurrence of a state change.

15. The computer readable program storage unit of claim 14, wherein said first reference heart beat complex template comprises at least one first matched filter.

16. The computer readable program storage unit of claim 15, wherein said at least one heart beat complex of said sequential plurality of heart beat complexes has a matched filter output to said first reference heart beat complex template within a first value of a fourth matched filter threshold.

17. The computer readable program storage unit of claim 1, wherein said comparing comprises using a matched filter on at least a portion of each heart beat complex in a moving window.

18. The computer readable program storage unit of claim 1, wherein said method further comprises taking an action in response to said indicating, wherein said action is providing a warning of said state change, logging a time of said state change, computing one or more state change indices, logging one or more computed state change indices, providing at least one treatment of said state change, or two or more thereof.

19. The computer readable program storage unit of claim 1, wherein said determination further comprises analyzing one or more of a pulse shape, an R wave amplitude, an apex cardiogram, or a pressure wave, to validate or classify said state change.

20. The computer readable program storage unit of claim 1, further comprising a second reference heart beat complex template, wherein said indicating said occurrence of said state change is based upon both said determination that said heart beat complex fails to match said first reference heart beat complex template and a second determination that said heart beat complex fails to match said second reference heart beat complex template.

21. The computer readable program storage unit of claim 1, wherein said obtaining further comprises obtaining data relating to at least a portion of a plurality of heart beat complexes;

and said indicating is based upon a determination that at least one said heart beat complex of said plurality of heart beat complexes fails to match said first reference heart beat complex template.

22. A computer readable program storage unit encoded with instructions that, when executed by a computer, perform a method for indicating an occurrence of a state change, comprising:

obtaining data relating to at least a portion of a heart beat complex from a patient;

comparing said at least said portion of said heart beat complex with a corresponding portion of a first reference heart beat complex template of said patient, wherein said first reference heart beat complex template comprises at least a first matched filter;

generating a time series of outputs of said first matched filter;

building a second matched filter from said time series of outputs of said first matched filter; and

,

indicating an occurrence of a state change based upon a determination that said output of said second matched filter matches a matched filter output template.