Hearing Prosthesis Fitting Using Post-Auricular Muscle Reflex

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Solution Overview

Problem

Current cochlear implant fitting methods face challenges in accurately determining optimal stimulation levels due to weak correlations with desired parameters, particularly for patients with limited auditory experiences or communication abilities, and existing objective measures are either difficult to measure or show limited detectability.

Innovation Solution

The use of post-auricular muscle reflex (PAMR) responses to determine the operating characteristics of the hearing prosthesis system, including defining output compression functions and minimal/maximal stimulation amplitudes based on PAMR amplitude growth functions, through iterative stimulus processes and bio-signal acquisition systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If eCAP is used as an objective measure for fitting, then measurement is easy, but correlation with MCL and THR is weak

Engineering Contradiction:

Improveease of measurementVSAvoidcorrelation with MCL and THR

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent introduces the electrically evoked stapedius reflex (eSRT) as an intermediary measure that bridges the gap between easy measurement and strong correlation with target parameters. The eSRT serves as a mediator that is both objectively measurable and shows high correlation (r=0.92-0.95) with both MCL and THR, resolving the contradiction between ease of measurement and measurement precision.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If eSRT is used to measure MCL correlation, then correlation with MCL is high, but measurement is difficult due to movement artifacts

Engineering Contradiction:

Improvecorrelation with MCLVSAvoidmeasurement reliability

Core Design Contradiction:

Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent replaces the mechanical impedance probe method with an electrical recording approach. Instead of using a mechanical probe that is susceptible to movement artifacts, the system uses electrical recordings from the stapedius muscle to detect the eSRT, thereby eliminating the measurement reliability issues associated with mechanical probing while maintaining high correlation with MCL.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If behavioral measures are used for fitting, then accurate fitting parameters can be obtained, but patients with limited auditory experiences or communication abilities cannot provide reliable responses

Engineering Contradiction:

Improvefitting parameter accuracyVSAvoidapplicability to all patient types

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent enables the patient's auditory system to serve itself by using objective physiological responses (eSRT) that automatically indicate hearing status without requiring patient participation, communication, or auditory experience. The system self-evaluates through measurable physiological responses, making it applicable to all patients including those with limited auditory experiences or communication abilities.

Inventive Principle:

Principle #25Self-service

4Measurement precision

If multiple objective measures are used to overcome limitations of individual measures, then comprehensive fitting information can be obtained, but measurement time and complexity increase

Engineering Contradiction:

Improvecomprehensive fitting informationVSAvoidmeasurement time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent segments the fitting process into distinct phases: initial objective measurement using eSRT to establish baseline parameters, followed by optional refinement with other measures only when necessary. This segmentation allows comprehensive fitting information to be obtained efficiently by performing only the necessary measurements, reducing overall measurement time and complexity while maintaining precision.

Inventive Principle:

Principle #1Segmentation

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

PAMR-based fitting provides reliable and quantitative evaluations of stimulation levels, potentially increasing the accuracy of cochlear implant fitting and overcoming limitations of existing methods by correlating well with desired fitting parameters, such as hearing threshold and comfort level, and reducing measurement time and complexity.

Implementation Method 1

determine a post-auricular muscle reflex (PAMR) response of a patient to an auditory stimulus signal

Methodology Applied

Scientific EffectPost-auricular muscle reflex:

Data Source

PatentEP2688640B1Post-auricular muscle response based hearing prosthesis fitting

Publication Date: 2019.11.20 MED EL ELEKTROMEDIZINISCHE GERAETE GMBH

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AI summary

An arrangement is described for fitting a hearing prosthesis system to a prosthesis patient. The PAMR measurement determines a post-auricular muscle reflex (PAMR) response of the patient to an auditory stimulus signal. For example, the PAMR response may include a PAMR amplitude growth function or a PAMR threshold stimulus level at which a PAMR is measured in the patient. Then a patient fitting module sets an operating characteristic of the hearing prosthesis system based on the PAMR response.