Electrode Pad Gel Composition for Noise Reduction During CPR

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Solution Overview

Problem

Existing electrode pads with strong acid gels used for reducing DC offset voltage are inflexible and cause skin irritation, and they fail to enable electrocardiogram analysis during chest compression due to noise interference, which necessitates interrupting CPR for electrocardiogram analysis.

Innovation Solution

An electrode pad with a conductor layer, such as tin foil, and an adhesive gel layer containing 0.1 wt% or more of SnCl2·2H2O with a pH of 3 to 6, which reduces noise interference during chest compression, allowing continuous electrocardiogram analysis without skin irritation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a strong acid gel is used to reduce DC offset voltage, then the DC offset voltage is reduced, but the flexibility of the electrode pad is lowered and skin irritation occurs

Engineering Contradiction:
ImproveDC offset voltage reductionVSAvoidflexibility and skin safety
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent changes the chemical parameters of the gel by specifying a pH range of 2-4 (weakly acidic) instead of strong acid, and controls the concentration of tin salts at 0.1-5 wt%. This parameter optimization maintains the ability to reduce DC offset voltage while improving flexibility and reducing skin irritation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The electrode pad uses a composite structure combining a conductive layer (tin foil or conductive rubber), a weakly acidic gel layer with tin salts, and optionally a protective layer. This composite material approach allows each layer to contribute specific functions: the conductive layer provides electrical conductivity, the weakly acidic gel reduces DC offset while being skin-friendly, and the protective layer maintains flexibility.

Inventive Principle:
Principle #40Composite materials

2Loss of time

If chest compression is performed in advance of defibrillation, then the rescue time is reduced, but noises from chest compression interfere with automatic electrocardiogram analysis

Engineering Contradiction:
Improverescue timeVSAvoidelectrocardiogram analysis accuracy
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

The patent converts the harmful effect of chest compression noises into a beneficial outcome by using a gel composition with tin salts that specifically suppresses noise generation. The weakly acidic gel with controlled tin salt concentration transforms the mechanical disturbance from chest compression into minimal electrical noise, allowing continuous monitoring during CPR.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

By optimizing the gel's chemical composition (pH 2-4, tin salts 0.1-5 wt%), the patent changes the electrical properties of the electrode-skin interface to reduce noise sensitivity. This allows the system to maintain measurement precision even during chest compression, eliminating the need to interrupt CPR for analysis.

Inventive Principle:
Principle #35Parameter changes

3Duration of action of stationary object

If the metal layer is made thick to prevent corrosion, then the storage period is extended, but the flexibility and skin contacting property are impaired

Engineering Contradiction:
Improvestorage periodVSAvoidflexibility and skin contacting property
Core Design Contradiction:
Duration of action of stationary objectVSEase of operation

Solution Approach 1:

The patent changes the chemical environment by using a weakly acidic gel with controlled tin salt concentration, which provides corrosion protection without requiring a thick metal layer. The optimized chemical parameters allow the use of thinner conductive layers that maintain flexibility and skin contact properties while still preventing corrosion during storage.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The electrode pad effectively minimizes noise interference during CPR, enabling uninterrupted electrocardiogram analysis and maintaining flexibility and skin safety, with the adhesive gel layer preventing corrosion and allowing long-term storage without thickness loss.

Implementation Method 1

an adhesive gel layer which is stacked on one surface of the conductor layer, the adhesive gel layer containing 0.1 wt% or more of SnCl2·2H2O, and having a pH of 3 to 6

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

a metal layer in an electrode must be thick in consideration of corrosion due to oxidation of the electrode

Methodology Applied
Scientific EffectChemical protection: Oxidation

Data Source

PatentEP2796092B1Electrode pad
Publication Date: 2017.09.20 NIHON KOHDEN CORP
  • EP2796092B1 patent drawingFigure 1
  • EP2796092B1 patent drawingFigure 2
  • EP2796092B1 patent drawingFigure 3

AI summary

An electrode pad includes: a conductor layer; and an adhesive gel layer which is stacked on one surface of the conductor layer, the adhesive gel layer which contains 0.1 wt% or more of SnCl2·2H2O, and which has a pH of 3 to 6. The conductor layer may a conductive metal layer. The conductor layer may include a tin foil.