Cardiac Episode Classification Algorithm Using Sinus Template Matching

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Manual review of cardiac episode data by clinicians is time-consuming and challenging due to increased memory capacity and diagnostic complexity in implantable medical devices, leading to reduced quality of patient management.

Innovation Solution

An algorithm using a sinus template and template matching to classify cardiac episodes by comparing ventricular EGM signals, incorporating predetermined thresholds for R-R intervals and P-R intervals, and utilizing both near-field and far-field EGM channels for robust classification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If automated algorithms are used for post-processing cardiac episodes, then the time required for review is reduced and productivity increases, but the complexity of the classification system increases

Engineering Contradiction:
Improveepisode review throughputVSAvoidclassification algorithm complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The classification algorithm is divided into multiple independent modules: rhythm detection module, morphology analysis module, template matching module, and classification decision module. Each module handles a specific aspect of episode analysis, making the overall complex system manageable and maintainable while achieving high automation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary rhythm classification and morphology assessment before final episode classification. By pre-processing and pre-categorizing episode characteristics using template matching and interval analysis, the system reduces the computational burden on the final classification stage, improving overall efficiency.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If manual review of episodes is performed, then classification accuracy can be maintained, but the time required for review increases significantly

Engineering Contradiction:
Improveepisode classification accuracyVSAvoidclinician review time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The classification algorithm incorporates feedback mechanisms where classification results are continuously refined based on comparison with established templates and morphological patterns. The system provides confidence scores for each classification, allowing clinicians to review only uncertain cases, thereby maintaining high accuracy while reducing overall review time.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces manual visual inspection and cognitive analysis with automated signal processing algorithms, template matching, and morphological analysis. This substitution of mechanical/computational methods for human manual review maintains classification accuracy while dramatically reducing the time required.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If more episode data is stored in the IMD, then diagnostic capability improves, but the time required to review the data increases

Engineering Contradiction:
Improvediagnostic capabilityVSAvoiddata review time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The algorithm extracts and analyzes only the most diagnostically relevant features from stored episode data, such as P-R intervals, R-R intervals, and ventricular EGM morphology. By selectively extracting key parameters rather than reviewing all raw data, the system maintains diagnostic capability while significantly reducing review time.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system performs partial analysis of episode data by focusing on critical morphological features and intervals that are most indicative of arrhythmia type. Rather than comprehensively analyzing every aspect of the stored data, the algorithm applies targeted analysis to the most diagnostic elements, achieving effective diagnosis with reduced processing time.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS8437840B2Episode classifier algorithm
Publication Date: 2013.05.07 MEDTRONIC INC
  • US8437840B2 patent drawing
  • US8437840B2 patent drawing
  • US8437840B2 patent drawing

AI summary

The present disclosure is directed to the classification of cardiac episodes using an algorithm. In various examples, an episode classification algorithm evaluates electrogram signal data collected by an implantable medical device. The episode classification algorithm may classify may include a sinus template and a comparison of the electrogram signal to the sinus template. Possible classifications of the cardiac episode may include, for example, unknown, inappropriate, appropriate, supraventricular tachycardia, ventricular tachycardia, ventricular fibrillation or ventricular over-sensing.