Bone Conduction Transducer Network for Mid-High Force Output

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Solution Overview

Problem

Electromagnetic vibrators of variable reluctance type in bone conduction applications face limited force output at mid and high frequencies due to high inductive input impedance, which restricts their ability to compensate for sensorineural hearing loss and treat unilateral deafness, especially in high frequency ranges.

Innovation Solution

An intermediate passive electric circuit network comprising an inductor in series with a capacitor is introduced between the amplifier and the vibrator to maximize voltage across the capacitor for the treble range, and a second capacitor in parallel with a resistor is added to enhance mid frequency gain, thereby increasing force output across a wider frequency range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If an electromagnetic vibrator of variable reluctance type is used in bone conduction applications, then the device can operate with a compact structure and bone-anchored connection, but the force output at mid and high frequencies is limited due to high inductive input impedance

Engineering Contradiction:
Improveforce outputVSAvoidinductive input impedance
Core Design Contradiction:
ForceVSObject-affected harmful factors

Solution Approach 1:

An intermediate passive electric circuit network comprising an inductor and capacitor is introduced between the amplifier and the vibrator terminals. This intermediary network transforms the electrical characteristics to maximize voltage across the capacitor for the treble frequency range, thereby increasing force output without changing the vibrator itself.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the electrical parameters by introducing reactive components (inductor and capacitor) that modify the impedance characteristics of the system. By selecting specific values for L and C, the network optimizes voltage delivery to the vibrator at mid and high frequencies, overcoming the limiting effect of the vibrator's inherent inductive impedance.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the vibrator is directly connected to the amplifier, then the circuit is simple, but the high frequency gain is poor due to battery voltage limitations

Engineering Contradiction:
Improvecircuit complexityVSAvoidhigh frequency gain
Core Design Contradiction:
Device complexityVSPower

Solution Approach 1:

A passive electric circuit network serves as an intermediary between the amplifier and vibrator, enabling improved high frequency gain without requiring changes to the amplifier or battery. The network uses energy storage elements to deliver higher voltage to the vibrator at frequencies where direct connection would be limited by battery voltage.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Force

If a capacitor is connected in series with the vibrator terminals to increase output force, then force output improves, but output force at lower frequencies is reduced due to signal blocking

Engineering Contradiction:
Improveoutput forceVSAvoidfrequency range coverage
Core Design Contradiction:
ForceVSDuration of action of moving object

Solution Approach 1:

The invention uses a composite electrical network combining both inductive and capacitive elements. This composite approach allows the circuit to provide impedance transformation and voltage boosting across a broad frequency range, avoiding the frequency-selective blocking effect of a simple series capacitor while still achieving increased force output.

Inventive Principle:
Principle #40Composite materials

4Force

If the inductive impedance is reduced to improve high frequency response, then force output increases, but power consumption increases

Engineering Contradiction:
Improveforce outputVSAvoidpower consumption
Core Design Contradiction:
ForceVSUse of energy by moving object

Solution Approach 1:

The passive intermediary network transforms the electrical characteristics between amplifier and vibrator, enabling improved force output without increasing power consumption. The network uses reactive energy storage rather than resistive energy dissipation, so the amplifier delivers the same power while the voltage transformation achieves higher force at the vibrator.

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

The solution significantly enhances force output in the mid and high frequency ranges, improving the ability to compensate for hearing losses and address sound shadows, while maintaining force levels in the low frequency range.

Implementation Method 1

inductor and capacitor values are then determined so that the voltage across the capacitor is maximized for the treble (high frequency) range

Methodology Applied
Scientific EffectElectrical resonance: Resonance

Implementation Method 2

An intermediate passive electric circuit network comprising an inductor in series with a capacitor is introduced between the amplifier and the vibrator

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 3

An intermediate passive electric circuit network comprising an inductor in series with a capacitor is introduced between the amplifier and the vibrator

Methodology Applied
Scientific EffectInductance: Inductor

Implementation Method 4

electromagnetic vibrator of variable reluctance type

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 5

electromagnetic vibrator of variable reluctance type

Methodology Applied
Scientific EffectMagnetic reluctance: Magnetic Reluctance

Data Source

PatentEP2673964B1Network for bone conduction transducers
Publication Date: 2019.04.03 OSSEOFON AB
  • EP2673964B1 patent drawingFigure 1a~1b
  • EP2673964B1 patent drawingFigure 2a~2b
  • EP2673964B1 patent drawingFigure 3a~3c

AI summary

An electrical network for driving electromagnetic bone conduction vibrator/transducer of variable reluctance type which is applied between the vibrator terminals and the power amplifier terminals so that the vibrator mechanical output is maximized in the mid and high frequencies.