Wide QRS detector
First Claim
1. A system comprising:
- a cardiac signal sensing circuit configured to sense a cardiac signal segment when operatively coupled to electrodes that contact a patient, wherein the cardiac signal segment includes a QRS complex;
a processor circuit communicatively coupled to the cardiac signal sensing circuit, wherein the processor circuit includes;
a peak detector circuit configured to determine a time of a maxima and a time of a minima in the sensed cardiac signal segment; and
a QRS complex time duration circuit configured to;
determine an isoelectric amplitude value of the cardiac signal segment;
identify, as a Q time in the QRS complex, a time where the amplitude of the sensed cardiac signal segment deviates from the first isoelectric amplitude value by a specified amplitude threshold value;
determine an isoelectric value time after the determined maxima and minima times that the cardiac signal segment returns to the same or a different isoelectric amplitude value;
identify, as an S time in the QRS complex, a time that follows both the determined maxima and minima times and precedes the isoelectric value time, wherein the amplitude of the sensed cardiac signal segment at the identified S time satisfies a specified amplitude change criterion from the isoelectric amplitude value, and wherein the amplitude change criterion is chosen according to a determined relation of the maxima time to the minima time; and
generate a value of a time duration of the QRS complex in the cardiac signal segment using the identified Q time and S time.
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Accused Products
Abstract
A system comprises a cardiac signal sensing circuit and a processor circuit. To detect a QRS duration, the processor circuit determines an isoelectric amplitude value of the cardiac signal segment, identifies a time where the cardiac signal segment amplitude deviates from the first isoelectric amplitude value by a specified threshold deviation value as a Q time, determines an isoelectric value time after the determined maxima and minima times that the cardiac signal segment returns to the same or a different isoelectric amplitude value, identifies a time that follows both the determined maxima and minima times and precedes the isoelectric value time as an S time, wherein the cardiac signal segment amplitude at the identified S time satisfies a specified amplitude change criterion from an isoelectric amplitude value, and determines a time duration of the QRS complex in the cardiac signal segment using the identified Q and S times.
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Citations
20 Claims
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1. A system comprising:
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a cardiac signal sensing circuit configured to sense a cardiac signal segment when operatively coupled to electrodes that contact a patient, wherein the cardiac signal segment includes a QRS complex; a processor circuit communicatively coupled to the cardiac signal sensing circuit, wherein the processor circuit includes; a peak detector circuit configured to determine a time of a maxima and a time of a minima in the sensed cardiac signal segment; and a QRS complex time duration circuit configured to; determine an isoelectric amplitude value of the cardiac signal segment; identify, as a Q time in the QRS complex, a time where the amplitude of the sensed cardiac signal segment deviates from the first isoelectric amplitude value by a specified amplitude threshold value; determine an isoelectric value time after the determined maxima and minima times that the cardiac signal segment returns to the same or a different isoelectric amplitude value; identify, as an S time in the QRS complex, a time that follows both the determined maxima and minima times and precedes the isoelectric value time, wherein the amplitude of the sensed cardiac signal segment at the identified S time satisfies a specified amplitude change criterion from the isoelectric amplitude value, and wherein the amplitude change criterion is chosen according to a determined relation of the maxima time to the minima time; and generate a value of a time duration of the QRS complex in the cardiac signal segment using the identified Q time and S time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. An ambulatory medical device comprising:
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a cardiac signal sensing circuit configured to sense a cardiac signal segment when operatively coupled to electrodes that contact a patient, wherein the cardiac signal segment includes a QRS complex; a peak detector circuit configured to determine a time of a maxima and a time of a minima in the cardiac signal segment; and a QRS complex time duration circuit is configured to; determine a time of return to an isoelectric amplitude value after the determined maxima and minima times of the cardiac signal segment; generate a value of an S time of the QRS complex as a time, following the determined maxima and minima times and preceding the time of return to the isoelectric amplitude value, at which the amplitude of the sensed cardiac signal segment satisfies a specified amplitude change criterion from the isoelectric amplitude value, and wherein the amplitude change criterion is chosen according to a determined relation of the maxima time to the minima time; and calculate and store a value of time duration of the QRS complex using the generated value of the S time. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification