Body Analysis Scale Contact Plate Galvanic Isolation

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Solution Overview

Problem

Existing body analysis scales face issues with electrode design, including sharp edges, material limitations, discomfort due to cold contact, difficulty in cleaning, and interference from direct current, which affect measurement accuracy and user experience.

Innovation Solution

The measuring elements are positioned within or behind the contact plate, ensuring galvanic isolation and eliminating direct contact with the user, allowing for improved design and reducing interference, while using a contact plate between the user and electrodes to prevent discomfort and facilitate cleaning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If electrodes are made of metal with edges for effective measurement, then measurement precision is improved, but the electrodes can injure users and become slippery when wet

Engineering Contradiction:
Improvemeasurement precisionVSAvoiduser injury and slipperiness
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a contact plate as an intermediary component between the user's foot and the measuring electrode. The contact plate made of non-slip, non-injurious material transmits the electrical signal while eliminating direct contact hazards. This mediator resolves the contradiction by maintaining measurement functionality while removing harmful edges and slipperiness.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct mechanical contact between metal electrodes and skin with an indirect coupling through the contact plate. This substitution eliminates the mechanical harm (sharp edges) while preserving the electrical measurement function through capacitive or resistive coupling.

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

2Measurement precision

If electrodes are attached on the side facing the user for direct contact measurement, then measurement precision is improved, but design possibilities are limited and cleaning becomes difficult

Engineering Contradiction:
Improvemeasurement precisionVSAvoiddesign flexibility and cleaning ease
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

Instead of attaching electrodes on the user-facing side for direct contact, the patent inverts the arrangement by placing electrodes on the opposite side of the contact plate. The user contacts the smooth outer surface, while electrodes remain hidden on the inner or rear side, enabling both precise measurement and easy cleaning of the user-facing surface.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent moves the electrode arrangement from the user-contact surface to another dimension (inner side or rear side of the contact plate). This spatial reconfiguration allows the user-facing surface to be smooth and cleanable while electrodes remain positioned for effective measurement through the plate.

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

3Measurement precision

If electrodes are exposed for direct skin contact during measurement, then measurement precision is improved, but the measurement process becomes uncomfortable due to cold contact

Engineering Contradiction:
Improvemeasurement precisionVSAvoiduser comfort
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The contact plate serves as a thermal mediator between the user's foot and the electrode. Being larger and having different thermal properties, it reduces the cold sensation while maintaining electrical coupling, thus improving comfort without sacrificing measurement precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Measurement precision

If measuring elements are in direct contact with the user for accurate bioelectrical impedance measurement, then measurement precision is improved, but direct current can falsify the measuring signal

Engineering Contradiction:
Improvemeasurement precisionVSAvoidsignal accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The contact plate acts as an electrical intermediary that enables measurement while blocking direct current interference. Through capacitive coupling or AC signal transmission through the plate, the system achieves accurate bioelectrical impedance measurement without DC falsification.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This configuration enhances user comfort, design flexibility, and measurement accuracy by preventing direct current interference and reducing wear, while allowing for precise bioelectrical impedance measurements and calculation of body fat percentage and other values.

Implementation Method 1

measuring elements (2) for measuring a at least with a variable correlating to a body value

Methodology Applied
Scientific EffectBioelectrical impedance: Electrical Resistance

Implementation Method 2

a galvanic isolation of the measuring element from the person to be analyzed, so that a measuring signal cannot be falsified by a direct current

Methodology Applied
Scientific EffectGalvanic isolation: Electrical Resistance

Data Source

PatentEP2354771B1Body analysis scales
Publication Date: 2019.06.26 LEIFHEIT
  • EP2354771B1 patent drawingFigure 1
  • EP2354771B1 patent drawingFigure 2
  • EP2354771B1 patent drawingFigure 3

AI summary

The scale (1) has measuring elements arranged within or on a side of a contact plate (11). The elements measure a variable of an evaluation electronics, where the variable correlates with a body value. The elements are designed as a capacitor plate and form a capacitor together with a body part i.e. foot sole, of a person, where the body part serves as another capacitor plate. The capacitor is acted upon with alternating current. The electronics determines a dielectric between a conductive layer in the body part and the former plate and calculates the variable from the determined dielectric.