QT-interval measurement in the electrocardiogram
AssigneePSI HEartSignals (global) Limited
InventorAnthony Charles Hunt
Life of this patent
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Abstract
A method and apparatus for measuring the QT interval of an electrocardiogram (ECG) signal is provided wherein the end of the T wave is identified from ECG data. The end of the T wave is defined as the first time of intersection at which an upright T wave of a first set of derived ECG signal data intersects an inverted T wave of a second set of derived ECG signal data. The intersection of the two sets of ECG data is along an isoelectric line within the trough after the positive T wave peak when the superimposed isoelectric baselines from the upright and inverted ECG signals demonstrate the best least squares fit.
Claims39
A method of measuring a QT interval of an electrocardiogram (ECG) signal wherein an end of a T wave is identified from ECG data, the method comprising the steps of:
- (a) acquiring ECG signal data from a signal acquisition apparatus or from a data storage;
- (b) deriving a first set of ECG signal data from the acquired ECG signal data using an electronic system;
- (c) inverting the first set of ECG signal data to derive a second set of ECG signal data using the electronic system, said second set of ECG signal data comprising an inverted set of said first set of ECG signal data;
- and
- (d) determining the end of the T wave using the electronic system by reference to timing of at least one intersection at which an upright T wave of said first set of derived ECG signal data intersects an inverted T wave of a said second set of derived ECG signal data, the two sets of ECG data being superimposed so as to maximize data fit over a segment of ECG signal after a peak of the positive T wave.
An apparatus for measuring the QT interval of an electrocardiogram (ECG) signal by identifying an end of a T wave from ECG data, said apparatus comprising:
- (a) means for acquiring ECG signal data;
- (b) means for deriving a first set of ECG signal data from the acquired ECG signal data;
- (c) means for inverting the first set of ECG signal data to derive a second set of ECG signal data, said second set of ECG signal data comprising an inverted set of said first set of ECG signal data;
- and
- (d) means for determining the end of the T wave, said T -wave being defined as a first time of intersection at which an upright T wave of said first set of derived ECG signal data intersects an inverted T wave of said second set of derived ECG signal data, the two sets of data being superimposed so as to maximise data fit over a segment of the ECG signal after a peak of the positive T wave.
Dependencies are inferred from the claim text.