Combination of electrogram and intra-cardiac pressure to discriminate between fibrillation and tachycardia
First Claim
1. A method for detecting and classifying an arrhythmia, comprising:
- sensing a cardiac electrogram signal;
determining a cardiac rate in response to the sensed cardiac electrogram signal;
detecting an arrhythmia in response to the cardiac rate;
sensing an intracardiac pressure signal;
generating a parameter corresponding to a frequency content of the pressure signal;
comparing the parameter to predetermined criteria; and
classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein the sensed cardiac electrogram signal corresponds to an atrial signal, the determined cardiac rate corresponds to an atrial rate, and the sensed pressure signal corresponds to an atrial pressure signal, and wherein the first arrhythmia corresponds to atrial flutter and the second arrhythmia corresponds to atrial fibrillation.
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Accused Products
Abstract
A system and method for detecting and classifying cardiac arrhythmias based on cardiac pressure signals or the combination of cardiac electrical and cardiac pressure signals. A cardiac electrogram signal is sensed to derive a cardiac rate from which an arrhythmia detection is made when the cardiac rate meets arrhythmia detection criteria. An intracardiac pressure signal is sensed to derive an indicator of tachycardia based on an analysis of the pressure signal in either the time domain or frequency domain. The detected arrhythmia is classified as tachycardia or fibrillation based on the tachycardia indicator wherein the tachycardia indicator is compared to tachycardia detection criteria and the arrhythmia is classified as tachycardia if tachycardia detection criteria are met and the arrhythmia is classified as fibrillation if the tachycardia detection criteria are not met.
39 Citations
31 Claims
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1. A method for detecting and classifying an arrhythmia, comprising:
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sensing a cardiac electrogram signal; determining a cardiac rate in response to the sensed cardiac electrogram signal; detecting an arrhythmia in response to the cardiac rate; sensing an intracardiac pressure signal; generating a parameter corresponding to a frequency content of the pressure signal; comparing the parameter to predetermined criteria; and classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein the sensed cardiac electrogram signal corresponds to an atrial signal, the determined cardiac rate corresponds to an atrial rate, and the sensed pressure signal corresponds to an atrial pressure signal, and wherein the first arrhythmia corresponds to atrial flutter and the second arrhythmia corresponds to atrial fibrillation. - View Dependent Claims (2, 3, 4)
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5. A method for detecting and classifying an arrhythmia, comprising:
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sensing a cardiac electrogram signal; determining a cardiac rate in response to the sensed cardiac electrogram signal; detecting an arrhythmia in response to the cardiac rate; sensing an intracardiac pressure signal; generating a parameter corresponding to a frequency content of the pressure signal; comparing the parameter to predetermined criteria; and classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein the sensed cardiac electrogram signal corresponds to an atrial signal, the determined cardiac rate corresponds to an atrial rate, and the sensed pressure signal corresponds to a ventricular pressure signal, and wherein the first arrhythmia corresponds to atrial flutter and the second arrhythmia corresponds to atrial fibrillation.
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6. A method for detecting and classifying an arrhythmia, comprising:
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sensing a cardiac electrogram signal; determining a cardiac rate in response to the sensed cardiac electrogram signal; detecting an arrhythmia in response to the cardiac rate; sensing an intracardiac pressure signal; generating a parameter corresponding to a frequency content of the pressure signal; comparing the parameter to predetermined criteria; and classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein the sensed cardiac electrogram signal corresponds to a ventricular signal, the determined cardiac rate corresponds to a ventricular rate, and the sensed pressure signal corresponds to a ventricular pressure signal, and wherein the first arrhythmia corresponds to ventricular tachycardia and the second arrhythmia corresponds to ventricular fibrillation.
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7. A method for detecting and classifying an arrhythmia, comprising:
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sensing a cardiac electrogram signal; determining a cardiac rate in response to the sensed cardiac electrogram signal; detecting an arrhythmia in response to the cardiac rate; sensing an intracardiac pressure signal; generating a parameter corresponding to a frequency content of the pressure signal; comparing the parameter to predetermined criteria; and classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein generating the parameter further comprises; filtering the sensed pressure signal to remove high frequency pressure signals; subtracting the filtered pressure signal from the sensed pressure signal to generate a high frequency pressure signal; and determining an amplitude-related parameter in response to the high frequency signal.
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8. A method for detecting and classifying an arrhythmia, comprising:
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sensing a cardiac electrogram signal; determining a cardiac rate in response to the sensed cardiac electrogram signal; detecting an arrhythmia in response to the cardiac rate; sensing an intracardiac pressure signal; generating a parameter corresponding to a frequency content of the pressure signal; comparing the parameter to predetermined criteria; and classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein generating the parameter further comprises; filtering the sensed pressure signal to remove high frequency pressure signals; subtracting the filtered pressure signal from the sensed pressure signal to generate a high frequency pressure signal; rectifying the high frequency pressure signal; and integrating the high frequency pressure signal to determine an integral value. - View Dependent Claims (9)
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10. A method for detecting and classifying an arrhythmia, comprising:
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sensing a cardiac electrogram signal; determining a cardiac rate in response to the sensed cardiac electrogram signal; detecting an arrhythmia in response to the cardiac rate; sensing an intracardiac pressure signal; generating a parameter corresponding to a frequency content of the pressure signal; comparing the parameter to predetermined criteria; and classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein generating the parameter further comprises; computing a summation of sampled pressure signal points; comparing the summation to a previously determined summation of sampled pressure signal points; and determining a correlation between the summation and the previously determined summation. - View Dependent Claims (11)
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12. A method for detecting and classifying an arrhythmia, comprising:
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sensing a cardiac electrogram signal; determining a cardiac rate in response to the sensed cardiac electrogram signal; detecting an arrhythmia in response to the cardiac rate; sensing an intracardiac pressure signal; generating a parameter corresponding to a frequency content of the pressure signal; comparing the parameter to predetermined criteria; and classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein generating a parameter further comprises; performing a Fourier transform on the sensed pressure signal; determining the fundamental frequency of the Fourier transform; and determining if a peak exists at a non-harmonic frequency of the fundamental frequency. - View Dependent Claims (13)
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14. A method for detecting and classifying an arrhythmia, comprising:
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sensing a cardiac electrogram signal; determining a cardiac rate in response to the sensed cardiac electrogram signal; detecting an arrhythmia in response to the cardiac rate; sensing an intracardiac pressure signal; generating a parameter corresponding to a frequency content of the pressure signal; comparing the parameter to predetermined criteria; and classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein generating a parameter further comprises; performing a Fourier transform on the sensed pressure signal; defining a threshold frequency separating the low frequency components from the high frequency components of the Fourier transform; determining a low frequency peak magnitude as the magnitude of a low frequency peak occurring below the threshold frequency; determining a high frequency peak magnitude as the magnitude of a high frequency peak occurring above the threshold frequency; and computing a relation between the low frequency peak magnitude and the high frequency peak magnitude.
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15. A method for detecting and classifying an arrhythmia, comprising:
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sensing a cardiac electrogram signal; determining a cardiac rate in response to the sensed cardiac electrogram signal; detecting an arrhythmia in response to the cardiac rate; sensing an intracardiac pressure signal; generating a parameter corresponding to a frequency content of the pressure signal; comparing the parameter to predetermined criteria; classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria; selecting a therapy in response to the, wherein selecting a therapy further comprises; selecting an anti-tachycardia therapy in response to an atrial rate falling within an atrial detection threshold and the arrhythmia being classified as the first arrhythmia; selecting a defibrillation therapy in response to the atrial rate falling within a fibrillation detection threshold and the arrhythmia being classified as the second arrhythmia; selecting a first user-defined therapy in response to the atrial rate falling within the atrial detection threshold and the arrhythmia being classified as the second arrhythmia; and selecting a second user-defined anti-arrhythmia therapy in response to the atrial rate falling within the fibrillation detection threshold and the arrhythmia being classified as the first arrhythmia.
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16. A medical device, comprising:
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means for sensing a cardiac electrogram signal; means for determining a cardiac rate in response to the sensed cardiac electrogram signal; means for detecting an arrhythmia in response to the cardiac rate; means for sensing an intracardiac pressure signal; means for generating a parameter corresponding to a frequency content of the pressure signal; means for comparing the parameter to predetermined criteria; and means for classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein the sensed cardiac electrogram signal corresponds to an atrial signal, the determined cardiac rate corresponds to an atrial rate, and the sensed pressure signal corresponds to an atrial pressure signal, and wherein the first arrhythmia corresponds to atrial flutter and the second arrhythmia corresponds to atrial fibrillation. - View Dependent Claims (17, 18, 19)
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20. A medical device, comprising:
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means for sensing a cardiac electrogram signal; means for determining a cardiac rate in response to the sensed cardiac electrogram signal; means for detecting an arrhythmia in response to the cardiac rate; means for sensing an intracardiac pressure signal; means for generating a parameter corresponding to a frequency content of the pressure signal; means for comparing the parameter to predetermined criteria; and means for classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein the sensed cardiac electrogram signal corresponds to an atrial signal, the determined cardiac rate corresponds to an atrial rate, and the sensed pressure signal corresponds to a ventricular pressure signal, and wherein the first arrhythmia corresponds to atrial flutter and the second arrhythmia corresponds to atrial fibrillation.
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21. A medical device, comprising:
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means for sensing a cardiac electrogram signal; means for determining a cardiac rate in response to the sensed cardiac electrogram signal; means for detecting an arrhythmia in response to the cardiac rate; means for sensing an intracardiac pressure signal; means for generating a parameter corresponding to a frequency content of the pressure signal; means for comparing the parameter to predetermined criteria; and means for classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein the sensed cardiac electrogram signal corresponds to a ventricular signal, the determined cardiac rate corresponds to a ventricular rate, and the sensed pressure signal corresponds to a ventricular pressure signal, and wherein the first arrhythmia corresponds to ventricular tachycardia and the second arrhythmia corresponds to ventricular fibrillation.
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22. A medical device, comprising:
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means for sensing a cardiac electrogram signal; means for determining a cardiac rate in response to the sensed cardiac electrogram signal; means for detecting an arrhythmia in response to the cardiac rate; means for sensing an intracardiac pressure signal; means for generating a parameter corresponding to a frequency content of the pressure signal; means for comparing the parameter to predetermined criteria; and means for classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein means for generating the parameter further comprises; means for filtering the sensed pressure signal to remove high frequency pressure signals; means for subtracting the filtered pressure signal from the sensed pressure signal to generate a high frequency pressure signal; and means for determining an amplitude-related parameter in response to the high frequency signal.
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23. A medical device, comprising:
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means for sensing a cardiac electrogram signal; means for determining a cardiac rate in response to the sensed cardiac electrogram signal; means for detecting an arrhythmia in response to the cardiac rate; means for sensing an intracardiac pressure signal; means for generating a parameter corresponding to a frequency content of the pressure signal; means for comparing the parameter to predetermined criteria; and means for classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein means for generating the parameter further comprises; means for filtering the sensed pressure signal to remove high frequency pressure signals; means for subtracting the filtered pressure signal from the sensed pressure signal to generate a high frequency pressure signal; means for rectifying the high frequency pressure signal; and means for integrating the high frequency pressure signal to determine an integral value. - View Dependent Claims (24)
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25. A medical device, comprising:
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means for sensing a cardiac electrogram signal; means for determining a cardiac rate in response to the sensed cardiac electrogram signal; means for detecting an arrhythmia in response to the cardiac rate; means for sensing an intracardiac pressure signal; means for generating a parameter corresponding to a frequency content of the pressure signal; means for comparing the parameter to predetermined criteria; and means for classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein means for generating the parameter further comprises; means for computing a summation of sampled pressure signal points; means for comparing the summation to a previously determined summation of sampled pressure signal points; and means for determining a correlation between the summation and the previously determined summation. - View Dependent Claims (26)
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27. A medical device, comprising:
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means for sensing a cardiac electrogram signal; means for determining a cardiac rate in response to the sensed cardiac electrogram signal; means for detecting an arrhythmia in response to the cardiac rate; means for sensing an intracardiac pressure signal; means for generating a parameter corresponding to a frequency content of the pressure signal; means for comparing the parameter to predetermined criteria; and means for classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein means for generating a parameter further comprises; means for performing a Fourier transform on the sensed pressure signal; means for determining the fundamental frequency of the Fourier transform; and means for determining if a peak exists at a non-harmonic frequency of the fundamental frequency. - View Dependent Claims (28)
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29. A medical device, comprising:
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means for sensing a cardiac electrogram signal; means for determining a cardiac rate in response to the sensed cardiac electrogram signal; means for detecting an arrhythmia in response to the cardiac rate; means for sensing an intracardiac pressure signal; means for generating a parameter corresponding to a frequency content of the pressure signal; means for comparing the parameter to predetermined criteria; and means for classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein means for generating a parameter further comprises; means for performing a Fourier transform on the sensed pressure signal; means for defining a threshold frequency separating the low frequency components from the high frequency components of the Fourier transform; means for determining a low frequency peak magnitude as the magnitude of a low frequency peak occurring below the threshold frequency; means for determining a high frequency peak magnitude as the magnitude of a high frequency peak occurring above the threshold frequency; and means for computing a relation between the low frequency peak magnitude and the high frequency peak magnitude.
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30. A medical device, comprising:
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means for sensing a cardiac electrogram signal; means for determining a cardiac rate in response to the sensed cardiac electrogram signal; means for detecting an arrhythmia in response to the cardiac rate; means for sensing an intracardiac pressure signal; means for generating a parameter corresponding to a frequency content of the pressure signal; means for comparing the parameter to predetermined criteria; means for classifying the arrhythmia in response to the comparing; and means for selecting a therapy in response to the arrhythmia classification, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, and wherein means for selecting a therapy further comprises; means for selecting an anti-tachycardia therapy in response to an atrial rate falling within an atrial detection threshold and the arrhythmia being classified as the first arrhythmia; means for selecting a defibrillation therapy in response to the atrial rate falling within a fibrillation detection threshold and the arrhythmia being classified as the second arrhythmia; means for selecting a first user-defined therapy in response to the atrial rate falling within the atrial detection threshold and the arrhythmia being classified as the second arrhythmia; and means for selecting a second user-defined anti-arrhythmia therapy in response to the atrial rate falling within the fibrillation detection threshold and the arrhythmia being classified as the first arrhythmia.
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31. A computer readable medium having computer executable instructions for performing a method comprising:
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sensing a cardiac electrogram signal; determining a cardiac rate in response to the sensed cardiac electrogram signal; detecting an arrhythmia in response to the cardiac rate; sensing an intracardiac pressure signal; generating a parameter corresponding to a frequency content of the pressure signal; comparing the parameter to predetermined criteria; and classifying the arrhythmia in response to the comparing, wherein the arrhythmia is classified as a first arrhythmia in response to the parameter meeting the predetermined criteria and as a second arrhythmia in response to the parameter not meeting the predetermined criteria, wherein the sensed cardiac electrogram signal corresponds to an atrial signal, the determined cardiac rate corresponds to an atrial rate, and the sensed pressure signal corresponds to an atrial pressure signal. and wherein the first arrhythmia corresponds to atrial flutter and the second arrhythmia corresponds to atrial fibrillation.
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Specification