ECG P-Wave Detection Using Composite Feature Classification

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Solution Overview

Problem

Current cardiac electrophysiological signal analysis systems face challenges in accurately detecting characteristics, such as the P wave, which are crucial for diagnosing cardiac conditions like atrial fibrillation, due to irregularities and noise in ECG waveforms.

Innovation Solution

A system comprising an acquisition processor, a computation processor, and an output processor that identifies and measures features of ECG waveforms to calculate a composite feature value, comparing it to a classification threshold to determine the presence of characteristics like the P wave, using pattern classification algorithms like linear discriminant analysis to enhance detection accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If pattern classification algorithms with multiple features are used to detect cardiac characteristics, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system segments the detection process into distinct functional modules: an acquisition processor for signal acquisition, a computation processor for feature extraction and classification, and an output processor for result generation. This segmentation allows each module to specialize in specific tasks, improving overall detection precision while making the complex system more manageable and maintainable through modular architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The computation processor performs preliminary actions by pre-calculating multiple features (amplitude, width, area, slope) from the acquired signal and storing them for subsequent classification. This preliminary feature extraction prepares the data in advance, enabling the pattern classification algorithm to make more accurate decisions without requiring complex real-time computations during the actual detection moment.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If multiple features are measured and composite values calculated, then measurement precision is improved, but loss of time increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary feature extraction and stores multiple characteristics (amplitude, width, area, slope) in advance. This allows the pattern classification algorithm to quickly compare pre-computed features against stored patterns without performing complex calculations in real-time, thereby maintaining high detection accuracy while reducing processing time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system creates simplified copies of the complex signal by extracting key features (amplitude, width, area, slope) that represent the essential characteristics of cardiac waves. These feature copies are much easier and faster to process than the original complex waveform, enabling rapid classification while preserving the information needed for accurate detection.

Inventive Principle:
Principle #26Copying

3Productivity

If signal acquisition and processing are performed continuously, then productivity is improved, but use of energy increases

Engineering Contradiction:
Improvereal-time monitoring capabilityVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The system performs signal acquisition and processing in periodic cycles rather than continuous operation. The acquisition processor collects signals over defined time windows, the computation processor analyzes features during these periods, and results are generated periodically. This periodic operation maintains real-time monitoring productivity while allowing energy-saving idle states between processing cycles.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system applies partial action by selectively processing only the most relevant features (amplitude, width, area, slope) rather than analyzing the entire continuous signal in detail. This selective feature extraction maintains detection accuracy while reducing the computational energy required compared to exhaustive signal analysis.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS9724007B2System and method for detecting a characteristic in an ECG waveform
Publication Date: 2017.08.08 DRAGERWERK AG
  • US9724007B2 patent drawing
  • US9724007B2 patent drawing
  • US9724007B2 patent drawing

AI summary

An apparatus and method is provided that identifies the presence or absence of a P-wave within a set of ECG data. A computation processor identifies the R-wave and then analyses a section of the waveform within a predetermined time window preceding the detected R-wave peak. The waveform within the window is analysed to identify a candidate P-wave, and in response to identifying the candidate P-wave a first and second feature associated therewith is measured. A composite feature value is calculated from the first and second measures, and compared to a classification threshold value. In an exemplary embodiment, the first feature represents a height between a highest peak of the candidate P-wave and a trough of the Q-wave, and the second feature represents a time between the peak of the candidate P-wave and a peak of the R-wave.