Cardiac signal QT interval detection
AssigneeMedtronic, Inc.
InventorsGautham Rajagopal, Shantanu Sarkar
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Abstract
An example device for detecting one or more parameters of a cardiac signal is disclosed herein. The device includes one or more electrodes and sensing circuitry configured to sense a cardiac signal via the one or more electrodes. The device further includes processing circuitry configured to determine an R-wave of the cardiac signal and determine a previous RR interval of the cardiac signal and a current RR interval of the cardiac signal based on the determined R-wave. The processing circuitry is further configured to determine a search window based on one or more of the current RR interval or the previous RR interval, determine a T-wave of the cardiac signal in the search window, and determine a QT interval based on the determined T-wave and the determined R-wave.
Claims16
An insertable cardiac monitoring device configured to be subcutaneously inserted into a patient, the device comprising:
- a cover;
- a plurality of electrodes, at least one of the plurality of electrodes being disposed on a proximal portion of the cover and at least another one of the plurality of electrodes being disposed on a distal portion of the cover;
- sensing circuitry configured to sense a cardiac signal based on electrical activity of a heart of the patient via the one or more electrodes;
- and
- processing circuitry configured to:
- determine an R-wave of the cardiac signal;
- determine a previous RR interval of the cardiac signal based on the determined R-wave;
- determine a current RR interval of the cardiac signal based on the determined R-wave;
- determine a search window based on one or more of the current RR interval or the previous RR interval;
- weight amplitudes of samples more heavily that are more likely to be located where a T-wave is located in the search window than samples that are less likely to be located where the T-wave is located based on previous QT intervals or previous QTc intervals;
- determine the T-wave of the cardiac signal based on the weighted amplitudes of samples in the search window;
- determine at least one of a QT interval or a QTc interval based on the determined T-wave and the determined R-wave;
- and
- predict a tachyarrhythmia based at least in part on the at least one of the QT interval or the QTc interval.
A method comprising:
- sensing, by sensing circuitry via one or more electrodes, a cardiac signal;
- determining, by processing circuitry, an R-wave of the cardiac signal;
- determining, by the processing circuitry, a previous RR interval of the cardiac signal based on the determined R-wave;
- determining, by the processing circuitry, a current RR interval of the cardiac signal based on the determined R-wave;
- determining, by the processing circuitry, a search window based on one or more of the current RR interval or the previous RR interval;
- weighting, by the processing circuitry, amplitudes of samples more heavily that are more likely to be located where a T-wave is located in the search window than samples that are less likely to be located where the T-wave is located based on previous QT intervals or previous QTc intervals;
- determining, by the processing circuitry, the T-wave of the cardiac signal based on the weighted amplitudes of samples in the search window;
- determining, by the processing circuitry, a QT interval based on the determined T-wave and the determined R-wave;
- and
- predicting, by the processing circuitry, a tachyarrhythmia based on the at least one of the QT interval or the QTc interval.
A non-transitory, computer-readable storage medium storing a set of instructions that, when executed, cause a system to:
- sense a cardiac signal via one or more electrodes;
- determine an R-wave of the cardiac signal;
- determine a previous RR interval of the cardiac signal based on the determined R-wave;
- determine a current RR interval of the cardiac signal based on the determined R-wave;
- determine a search window based on one or more of the current RR interval or the previous RR interval;
- weight amplitudes of samples more heavily that are more likely to be located where T-wave is located in the search window than samples that are less likely to be located where the T-wave is located based on previous QT intervals or previous QTc intervals;
- determine the T-wave of the cardiac signal based on the weighted amplitudes of samples in the search window;
- determine a QT interval based on the determined T-wave and the determined R-wave;
- and
- predict a tachyarrhythmia based on the at least one of the QT interval or the QTc interval.
Dependencies are inferred from the claim text.