Biosignal Measurement Apparatus With Dynamic Input Impedance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Biosignal measurements, such as electrocardiographic or electromyographic, face issues with poor signal quality due to changing measurement conditions primarily caused by variations in tissue conductivity and the dynamics at the tissue-electrode interface, which existing technologies fail to adequately address.

Innovation Solution

An apparatus and method that apply a test input impedance to determine the response of biosignal characteristics and set a usage input impedance to optimize signal quality during biosignal measurement from the skin of a living object, particularly during fitness exercises, by adjusting the impedance based on changing conductivity conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed input impedance is used in the measuring device, then the device structure is simple, but the signal quality deteriorates due to changing skin conductivity during exercise

Engineering Contradiction:
Improvesignal qualityVSAvoidimpedance adjustment mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by making the input impedance adjustable rather than fixed. The measuring device dynamically adapts its input impedance based on the measured biosignal characteristics, allowing it to respond to changing skin conductivity conditions during exercise. This resolves the contradiction by enabling signal quality maintenance through dynamic adaptation while keeping the adjustment mechanism relatively simple.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback by continuously monitoring biosignal characteristics and using this information to adjust the input impedance. The device measures the biosignal, determines the skin conductivity conditions from the signal characteristics, and automatically adjusts the input impedance accordingly. This closed-loop feedback system maintains optimal signal quality without requiring complex manual intervention.

Inventive Principle:
Principle #23Feedback

2Reliability

If the input impedance is adjusted frequently to match changing conductivity, then signal quality is maintained, but the measurement time and energy consumption increase

Engineering Contradiction:
Improvesignal-to-interference ratioVSAvoidimpedance adjustment time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies periodic action by adjusting the input impedance at periodic intervals during the measurement process. Rather than continuously adjusting or adjusting with every minor change, the device periodically re-evaluates the biosignal characteristics and adjusts impedance accordingly. This approach maintains adequate signal quality while minimizing unnecessary adjustment time and energy consumption.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent changes the input impedance parameter based on measured biosignal characteristics. By monitoring changes in the biosignal that indicate variations in skin conductivity, the device adjusts the input impedance parameter to match the current measurement conditions. This parameter adaptation allows the system to maintain optimal signal quality without excessive adjustment frequency.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2140807B1Processing of biosignal
Publication Date: 2016.01.06 POLAR ELECTRO
  • EP2140807B1 patent drawingFigure 1~2
  • EP2140807B1 patent drawingFigure 3
  • EP2140807B1 patent drawingFigure 4

AI summary

An apparatus for use in connection with biosignal measurement from the skin of a living object, comprising means for applying (352, 354, 356) a test input impedance to the biosignal measurement, means for determining (350) a response of a biosignal characteristics to the test input impedance, and means for setting (352, 354, 356) a usage input impedance on the basis of the response.