ECG Analysis Algorithm for CPR Artifact Filtering

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing defibrillators struggle to accurately analyze cardiac rhythms during cardio-pulmonary resuscitation (CPR) due to CPR-induced artifacts, leading to unreliable shock determinations and inability to detect refibrillation, which can result in delayed or inappropriate treatment.

Innovation Solution

A method that combines upstream filtering and downstream decision-making using time-sequential ECG and CPR reference signal data sets to accurately identify arrhythmias treatable by electrotherapy, minimizing CPR interruptions and improving shock advisory accuracy through the SmartPause algorithm.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If CPR is performed continuously without interruption to maintain circulation, then patient survival chances are improved, but accurate detection of shockable rhythms becomes unreliable due to CPR-induced artifacts

Engineering Contradiction:
Improveaccuracy of shock determinationVSAvoiddelay in defibrillation
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the analysis approach into two distinct signal processing paths: one for detecting shockable rhythms during CPR (with artifact filtering) and another for confirming rhythms after CPR pause. This segmentation allows the system to maintain continuous CPR while still attempting rhythm detection, resolving the contradiction by enabling parallel operation of CPR and analysis rather than forcing a choice between them.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary rhythm analysis during CPR using artifact filtering algorithms before committing to a shock decision. By conducting preliminary detection during the CPR phase and then performing confirmatory analysis after pausing CPR, the system reduces the time loss associated with rhythm analysis while maintaining reliability through the two-stage verification process.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If CPR is paused to deliver a shock for treating refibrillation, then shock effectiveness is improved, but circulation support is interrupted

Engineering Contradiction:
Improveaccuracy of refibrillation detectionVSAvoidcirculation maintenance efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system uses feedback from the rhythm analysis to dynamically control CPR interruption decisions. By continuously monitoring for refibrillation during CPR and using this feedback to trigger selective pauses only when refibrillation is detected, the system improves refibrillation detection accuracy while minimizing unnecessary interruptions to circulation support.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The CPR control strategy is made dynamic rather than static. The system adapts CPR interruption decisions based on real-time rhythm analysis results, allowing continuous CPR when no refibrillation is detected and selective pausing when refibrillation is identified. This dynamic approach optimizes the balance between circulation maintenance and shock effectiveness.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If standard ECG analysis is used during CPR, then device complexity is minimized, but measurement precision deteriorates due to artifact contamination

Engineering Contradiction:
ImproveECG signal accuracyVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary artifact filtering algorithm that processes the ECG signal to remove CPR-induced artifacts before rhythm analysis. This intermediary processing step acts as a mediator between the raw contaminated signal and the rhythm detection algorithm, improving measurement precision while keeping the overall device complexity manageable by using established signal processing techniques.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system replaces manual CPR pausing (mechanical intervention) with automated artifact filtering and rhythm analysis (electronic/signal processing intervention). This substitution allows the device to automatically compensate for CPR artifacts through signal processing algorithms, improving ECG accuracy during CPR without requiring complex mechanical modifications to the defibrillator hardware.

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

Data Source

PatentEP2854627B1Apparatus for analyzing cardiac rhythm during cpr
Publication Date: 2018.08.29 KONINKLIJKE PHILIPS NV
  • EP2854627B1 patent drawingFigure 1
  • EP2854627B1 patent drawingFigure 2~4b
  • EP2854627B1 patent drawingFigure 3

AI summary

A diagnostic medical device (900) is described which incorporates an improved ECG analysis algorithm (600, 800) that identifies an arrhythmia treatable by a defibrillation shock, wherein the identification can occur even in the presence of underlying CPR artifact. The analysis algorithm allows for a shorter interval between the application of CPR compressions and the delivery of electrotherapy, and thus increases the likelihood of successful resuscitation. The medical device may also include a defibrillating electrotherapy circuit (920).