Electroacoustic Transducer Impedance Sensing for Cavity Depth Prediction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a lack of easy methods to determine the distance between a probe and a termination body within a cavity, particularly in hearing assessments where a probe is inserted into the ear canal, and there is a need for a novel approach to measure cavity characteristics.
Innovation Solution
An electroacoustic transducer is used to generate sound waves and measure impedance, with the impedance measurements correlated to cavity characteristics using a neural network trained to predict these characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a probe is inserted into the ear canal for hearing assessment, then hearing testing can be performed, but the distance between the probe and the eardrum (insertion depth) cannot be easily determined
Solution Approach 1:
The electroacoustic transducer is designed to perform multiple functions: it acts as both a speaker (actuator) to generate test sounds and as a sensor to measure impedance for determining insertion depth. This multi-functionality eliminates the need for separate measurement devices, making insertion depth determination as easy as performing the hearing test itself.
Solution Approach 2:
The transducer system performs self-measurement of insertion depth through impedance sensing while simultaneously performing the hearing assessment function. The system uses its own electrical characteristics (impedance) to determine its position, eliminating the need for external measurement tools or procedures.
2Adaptability or versatility
If traditional separate speaker and microphone systems are used for hearing assessment, then comprehensive testing can be performed, but device complexity and cost increase
Solution Approach 1:
The patent combines the speaker and microphone functions into a single electroacoustic transducer unit. The transducer generates test sounds through its speaker function and simultaneously measures acoustic impedance through its sensor function, integrating what would traditionally require separate devices into one unified component.
Solution Approach 2:
The electroacoustic transducer is designed as a universal device that performs both actuation (speaker function) and sensing (microphone/impedance measurement function). This multi-functionality reduces the overall system complexity while maintaining comprehensive hearing assessment capabilities.
3Measurement precision
If impedance measurement is used to determine cavity characteristics, then insertion depth can be measured, but the relationship between impedance and physical dimensions is complex and non-intuitive
Solution Approach 1:
The patent replaces complex mechanical measurement methods with electrical impedance measurement. Instead of physically measuring insertion depth with mechanical tools or optical sensors, the system uses electrical characteristics (impedance) of the transducer to infer physical dimensions, simplifying the measurement process.
Solution Approach 2:
The system measures changes in electrical impedance parameters (resistance, reactance, impedance magnitude) as the transducer is inserted into the cavity. These parameter changes correlate with physical position and cavity characteristics, providing a measurable electrical signature that can be used to determine insertion depth and other cavity properties.
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 method accurately predicts cavity characteristics such as insertion depth, temperature, and humidity, expanding the utility of speakers as sensors beyond traditional actuator roles.
Implementation Method 1
The electrical signal is converted to sound by the electroacoustic transducer that is part of the earphone
Implementation Method 2
operate in a sensor mode when measuring impedance across the at least two electrical terminals
Data Source
AI summary
A method of measuring characteristics of a cavity using an electroacoustic transducer (ET) includes inserting an ET having at least two electrical terminals into a proximal end of a cavity having a distal end defining a termination body, wherein the ET is configured to i) operate in a speaker mode thereby generating sound waves when an electrical signal is provided across the at least two electrical terminals, and ii) operate in a sensor mode when measuring impedance across the at least two electrical terminals, operating the ET in the speaker mode by applying an electrical signal across the at least two electrical terminals, operating the ET in the sensor mode by measuring impedance across the at least two electrical terminals, providing the measured impedance to a neural network configured to correlate impedance measurements of the ET to cavity characteristics, and predicting cavity characteristics based on output of the neural network.