Methods and devices for accurately classifying cardiac activity

Inventors

Allavatam, Venugopal • Palreddy, Surekha • Sanghera, Rick • Warren, Jay A.

Assignees

Cameron Health Inc

Abstract

Methods, systems, and devices for signal analysis in an implanted cardiac monitoring and treatment device such as an implantable cardioverter defibrillator. In illustrative examples, captured data including detected events is analyzed to identify likely overdetection of cardiac events. In some illustrative examples, when overdetection is identified, data may be modified to correct for overdetection, to reduce the impact of overdetection, or to ignore overdetected data. New methods for organizing the use of morphology and rate analysis in an overall architecture for rhythm classification and cardiac signal analysis are also discussed.

Core Innovation

The invention relates to an implantable medical device (IMD) having operational circuitry and a plurality of electrodes electrically coupled to the operational circuitry. The operational circuitry receives a cardiac electrical signal, detects a series of events, identifies intervals between consecutive detected events, and determines whether each event is likely a product of noisy signal, marking such events as suspect due to noise.

The operational circuitry analyzes each series of events, including events marked as suspect due to noise, using a set of rules directed at identifying a pattern of overdetection. The set of rules calls for analysis of at least two detected events to identify overdetection, and the operational circuitry determines whether a pattern of overdetection has been identified.

If overdetection is identified, the operational circuitry determines which detected events are likely due to overdetection, combines intervals around events likely due to overdetection, and discards detected event(s) likely due to overdetection. After completing the discarding steps, or if no pattern of overdetection is identified, the operational circuitry discards suspect event(s) due to noise and each interval that precedes and each interval that follows such suspect event.

The operational circuitry calculates a cardiac rate for the received cardiac electrical signal and comprises memory for storing cardiac electrical signal data to be later uploaded by a user of an external programmer adapted to communicate with the IMD. The operational circuitry is configured to determine whether abnormal or potentially malignant activity is occurring and, if so, to store data in the memory in response to the abnormal or potentially malignant activity.

Claims Coverage

The provided excerpt includes three independent claims. Across the claims, the coverage focuses on event detection, noise/suspect handling, rule-based identification of overdetection patterns using at least two detected events, discarding and combining intervals to correct for overdetection before calculating cardiac rate, and memory-based data storage in response to abnormal or potentially malignant activity; one claim further adds malignant cardiac rhythm detection and electrical therapy delivery.

The independent claims collectively cover an IMD that marks suspect events due to noisy signal, identifies overdetection patterns by rule-based analysis of at least two detected events, corrects intervals by combining or discarding overdetection-associated events, and calculates cardiac rate. The claims also cover storing cardiac electrical signal data for later upload in response to abnormal or potentially malignant activity, and one independent claim adds electrical therapy in response to a malignant cardiac rhythm.

Stated Advantages

Documented Applications