摘要:
The invention relates to devices that detect and/or treat tachyarrhythmias. The invention includes software systems that distinguish among various tachyarrhythmias in order to provide treatment for specific tachyarrhythmias. One aspect of the invention employs a methodology to provisionally detect ventricular tachycardia and/or fibrillation and thereafter apply a discrimination function to a series of measured intervals preceding the provisional detection. Discrimination is accomplished by sorting the intervals preceding provisional detection into bins corresponding to interval ranges and examining the relative distribution of the intervals within the bins.
摘要:
Techniques for evaluating cardiac electrical dyssynchrony are described. In some examples, an activation time is determined for each of a plurality of torso-surface potential signals. The dispersion or sequence of these activation times may be analyzed or presented to provide variety of indications of the electrical dyssynchrony of the heart of the patient. In some examples, the locations of the electrodes of the set of electrodes, and thus the locations at which the torso-surface potential signals were sensed, may be projected on the surface of a model torso that includes a model heart. The inverse problem of electrocardiography may be solved to determine electrical activation times for regions of the model heart based on the torso-surface potential signals sensed from the patient.
摘要:
Techniques for evaluating cardiac electrical dyssynchrony are described. In some examples, an activation time is determined for each of a plurality of torso-surface potential signals. The dispersion or sequence of these activation times may be analyzed or presented to provide variety of indications of the electrical dyssynchrony of the heart of the patient. In some examples, the locations of the electrodes of the set of electrodes, and thus the locations at which the torso-surface potential signals were sensed, may be projected on the surface of a model torso that includes a model heart. The inverse problem of electrocardiography may be solved to determine electrical activation times for regions of the model heart based on the torso-surface potential signals sensed from the patient.
摘要:
A medical device and associated method for discriminating cardiac events sense cardiac signals that includes determining whether a first match score is within one of a first match zone corresponding to a first cardiac event, and a second match zone corresponding to the first cardiac event, and determining whether a second match score is within one of the first match zone, the second match zone, and a third match zone corresponding to a second cardiac event different from the first cardiac event. One of increasing and decreasing an event counter is performed in response to both the determination of whether the first match score is within one of the first match zone and the second match zone and the determination of whether the second match score is within one of the first match zone, the second match zone, and the third match zone.
摘要:
Techniques are described for detecting a condition of a patient using a probability-correlation based model that integrates a plurality of parameters associated with the condition. A medical device that operates in accordance with the techniques obtains a plurality of parameters associated with the condition of the patient. The medical device obtains probabilities that the condition of the patient exists based on each single parameter separately and correlations between each of the parameters and the other ones of the parameters. After obtaining the probabilities and correlations associated with each of the parameters, the medical device determines whether the condition of the patient exists based on the determined probabilities and correlations. Such techniques may be particularly effective for use in distinguishing whether a rhythm of a patient is treatable, e.g., VT or VF, or non-treatable, e.g., SVT.
摘要:
A medical device and associated method for monitoring a patient's heart rhythm sense cardiac events and detect a sudden change in the heart rhythm in response to the sensed cardiac events. Detecting the sudden change includes determining a variability of intervals between the sensed cardiac events and switching between a low variability mode of operation and a high variability mode of operation in response to the variability of intervals. During the low variability mode, detecting the sudden change includes detecting an increase in the rate of cardiac events. During the high variability mode, detecting the sudden change includes detecting a sudden decrease in the variability of the cardiac event intervals. A concerning cardiac rhythm is detected in response to detecting the sudden change.
摘要:
Techniques are described for detecting a condition of a patient using a probability-correlation based model that integrates a plurality of parameters associated with the condition. A medical device that operates in accordance with the techniques obtains a plurality of parameters associated with the condition of the patient. The medical device obtains probabilities that the condition of the patient exists based on each single parameter separately and correlations between each of the parameters and the other ones of the parameters. After obtaining the probabilities and correlations associated with each of the parameters, the medical device determines whether the condition of the patient exists based on the determined probabilities and correlations. Such techniques may be particularly effective for use in distinguishing whether a rhythm of a patient is treatable, e.g., VT or VF, or non-treatable, e.g., SVT.
摘要:
The invention is directed to method and process for discriminating supraventricular tachycardia (SVT) with 1:1 atrial to ventricular conduction (AV conduction). Upon detection of a rapid heart rate, an implanted medical device may determine whether the rhythm exhibits insufficient evidence of sinus tachycardia, whether the rhythm exhibits 1:1 conduction, and whether an electrical signal corresponding to the rhythm exhibits a normal morphology. When these tests have been satisfied, the device determines that an SVT with 1:1 AV conduction has been detected.
摘要:
A medical device and associated method for discriminating cardiac events includes determining whether a first match score is within a first match zone having a first correlation with a non-treatable cardiac event, a second match zone having a second correlation with the non-treatable cardiac event less than the first correlation with the non-treatable event, a third match zone having a first correlation with a treatable cardiac event, and a fourth match zone having a second correlation with the treatable cardiac event greater than the first correlation with the treatable cardiac event. A determination is made as to whether a second match score and a third match score are within the first match zone, the second match zone, the third match zone and the fourth match zone to generate a first adjusting factor, and cardiac event evidence is accumulated in response to the first adjusting factor for discriminating cardiac events.
摘要:
A medical device and associated method for discriminating cardiac events includes sensing a cardiac signal spatially located across approximately a full duration of a predetermined sensing window. A match score is determined corresponding to the sensed cardiac signal. A beat feature of multiple beat features across less than the full duration of the sensing window is determined, the beat feature being selected from the multiple beat features in response to the match score. Cardiac event evidence is accumulated in response to the match score and the determined beat feature, and cardiac events are discriminated in response to the accumulated cardiac evidence.