Miniaturized ECG Cable with Distributed Resistive Wires

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Solution Overview

Problem

Conventional ECG cables are too bulky to be compatible with small-sized wearable measurement modules, hindering their integration and affecting patient comfort and workflow.

Innovation Solution

A miniaturized ECG cable is developed using a resistive wire cable with multiple resistive wires wound around a core, eliminating the need for a separate trunk cable connector, and incorporating flexible lead wires and high-permeability materials to distribute impedances, allowing for low and high inductance cables.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If serial protection resistors capable of high-energy absorption are required for every wire, then the safety and energy absorption capability is improved, but the trunk cable connector becomes rather bulky

Engineering Contradiction:
Improveenergy absorption capabilityVSAvoidtrunk cable connector size
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent divides the single bulky trunk cable connector into multiple separate connector components, each housing one or more protection resistors. This segmentation allows each resistor to be individually positioned and managed, reducing the overall volume requirement while maintaining the necessary energy absorption capability for each lead wire.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a planar arrangement of resistors in a single large connector to a three-dimensional distributed arrangement where resistors are positioned along the cable length. This dimensional change allows for more efficient space utilization and reduces the maximum volume required at any single location.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If conventional ECG cables are used, then the high-energy absorption capability is maintained, but the cable size is too large to be compatible with small-sized wearable measurement modules

Engineering Contradiction:
Improvehigh-energy absorption capabilityVSAvoidECG cable set size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent segments the ECG cable system into modular components including separate lead wires, distributed protection resistors, and a minimized trunk cable connector. This segmentation enables each component to be optimized independently, resulting in an overall reduction of cable set volume while preserving the high-energy absorption capability through strategically placed resistors.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs flexible insulation layers and thin protective coatings on the lead wires and resistors, replacing bulky rigid protective structures. This allows the cable components to be miniaturized while maintaining flexibility and safety, enabling compatibility with small-sized wearable measurement modules.

Inventive Principle:
Principle #30Flexible shells and thin films

3Measurement precision

If standard ICU ECG patient lead sets with low inductance are used, then bio-impedance respiration measurements at 48 kHz are enabled, but additional inductors and resistors are needed for OR applications which increases size and disables bio-impedance measurement

Engineering Contradiction:
Improvebio-impedance measurement capabilityVSAvoidcable component complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs parameter-changing materials, specifically ferrite beads with frequency-dependent magnetic properties, that can adapt their inductance characteristics based on the operating frequency. At lower frequencies (ECG signals), the ferrite beads present low inductance allowing bio-impedance measurements, while at higher frequencies (RF from surgical equipment), they present high inductance for suppression, eliminating the need for separate inductors and resistors.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements multi-functional ferrite beads that simultaneously serve as RF suppression elements, ECG signal transmission elements, and bio-impedance measurement enablers. This universal component replaces the need for separate inductors and resistors required in conventional OR lead sets, reducing device complexity while maintaining all necessary measurement capabilities across different operating conditions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 solution significantly reduces the size of the ECG cable set, enhancing compatibility with small-sized modules, improving patient friendliness, and enabling efficient bio-impedance measurements while maintaining high-energy absorption capabilities.

Implementation Method 1

each resistive wire has a resistance of at least 500 Ω and wherein the resistive wires are made of a material having a resistivity of at least 0.135 μΩ*m

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 2

serial protection resistors capable of high-energy absorption are required for every wire. Said resistors... are able to absorb minimally approx. 15 J (for 1 kOhm) each

Methodology Applied
Scientific EffectJoule Heating: Joule Heating

Implementation Method 3

dedicated OR ECG patient lead sets comprise additional 6.8 mH inductors... to suppress RF signals from the use of cauterization devices and electrical knifes

Methodology Applied
Scientific EffectFerromagnetism: Ferromagnetism

Implementation Method 4

ferrite beads or other high-permeability material to suppress RF signals

Methodology Applied
Scientific EffectMagnetic Field: Magnetic Field

Implementation Method 5

Standard ICU ECG patient lead sets should have low inductance to allow bio-impedance respiration measurements at 48 kHz

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Data Source

PatentEP3592223B1ECG cable for connection with an ECG monitor
Publication Date: 2020.11.25 KONINKLIJKE PHILIPS NV
  • EP3592223B1 patent drawingFigure 1~4
  • EP3592223B1 patent drawingFigure 5~6B
  • EP3592223B1 patent drawingFigure 7A~8

AI summary

The present invention relates to an ECG cable for connection with an ECG monitor. To achieve a miniaturization of the ECG cable and omitting the conventionally used trunk cable and trunk cable connector, the ECG cable comprises a core (2), a resistive wire cable (3a-3h) comprising a plurality of resistive wires (31-37) wound around the core and isolated with respect to each other, and two or more flexible lead wires (4), each connected to a respective resistive wire at its one end (40) and to an electrode (5) at its other end (41).