Single-Channel Sound Transducer with Frequency-Domain Spatial Encoding

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Solution Overview

Problem

Current ultrasound technology for three-dimensional imaging and structure detection is limited by high manufacturing costs, complexity, and space requirements due to the need for multiple channels and large arrays, which restricts its application and efficiency, especially in areas requiring high resolution.

Innovation Solution

A sound transducer with a single overall aperture comprising multiple subapertures, each generating a specific frequency spectrum, connected to a common electronic control channel, allowing for the generation and reception of a spatially structured sound field with reduced space and cost requirements, enabling efficient three-dimensional imaging and structure detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If array technology with multiple individually controlled transducer elements is used to generate structured sound fields for three-dimensional imaging, then measurement precision and resolution are improved, but device complexity and manufacturing costs increase significantly due to the large number of channels and connections required

Engineering Contradiction:
ImproveresolutionVSAvoidnumber of channels and connections
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The overall aperture is divided into multiple subapertures, each responsible for a specific frequency spectrum. This segmentation allows the system to encode spatial information in the frequency domain, enabling a single transducer element to perform functions that would otherwise require multiple elements with individual control channels.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different subapertures are assigned different frequency spectra through parameter variation (frequency assignment). This parameter change approach allows spatial encoding without requiring multiple control channels, as each subaperture's frequency characteristics carry spatial information that can be decoded to achieve three-dimensional imaging.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If large arrays with many transducer elements are used to achieve high resolution in three-dimensional imaging, then measurement precision is improved, but the space requirement and area occupied by the device increase

Engineering Contradiction:
ImproveresolutionVSAvoidspace requirement
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The invention transitions from spatial encoding (requiring large physical arrays) to frequency-domain encoding. By mapping spatial information to frequency spectra assigned to different subapertures, the system achieves three-dimensional imaging capabilities without requiring large physical space, effectively utilizing the frequency dimension instead of the spatial dimension.

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

3Adaptability or versatility

If multiple individually controlled transducer elements are used for spatially resolving recorded signals, then three-dimensional imaging capability is improved, but manufacturing costs increase by a factor of 100 to 1000 due to the large number of channels required

Engineering Contradiction:
Improvethree-dimensional imaging capabilityVSAvoidmanufacturing costs
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

Multiple subapertures that would traditionally require separate control channels are merged into a single transducer element connected to one control channel. The frequency-based encoding scheme allows the combined output of all subapertures to be processed through a single channel, dramatically reducing manufacturing costs while maintaining three-dimensional imaging capability.

Inventive Principle:
Principle #5Merging (Combining)

4Shape

If acoustic holograms or phase plates are used to generate structured ultrasonic fields, then spatial structuring of sound fields is improved, but the system becomes unsuitable for airborne sound or low frequency ranges due to attenuation and multiple reflections

Engineering Contradiction:
Improvestructured sound fieldVSAvoidsuitability for airborne sound or low frequency
Core Design Contradiction:
ShapeVSAdaptability or versatility

Solution Approach 1:

The invention replaces mechanical structuring methods (acoustic holograms, phase plates) with a frequency-assignment approach that encodes spatial information in the frequency domain. This substitution eliminates the problems of attenuation and multiple reflections associated with mechanical methods, enabling the system to work effectively with airborne sound and low frequency ranges while still generating structured sound fields.

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

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 solution significantly reduces costs by a factor of 100 to 1000 and increases measurement dimensionality by a factor of 3, while enabling the use of ultrasound sensors across various sound ranges, including airborne and tissue applications, with reduced power consumption and data volume, making it suitable for medical and industrial use.

Implementation Method 1

Sound transducers are used. These typically emit an acoustic signal in the form of sound pressure from an electrical signal (voltage or current), or conversely, generate an electrical signal from an acoustic signal received via the transducer. Piezo elements, for example, can be used for this purpose.

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

An overall aperture (10) comprising a plurality of subapertures (12, 14, 16, 18), wherein the subapertures (12, 14, 16, 18) are configured to receive/detect or generate ultrasound with a specific frequency spectrum, wherein the specific frequency spectra of at least two of the subapertures (12, 14, 16, 18) differ, wherein all subapertures (12, 14, 16, 18) are connected to the same electronic control channel.

Methodology Applied
Scientific EffectFrequency spectrum spatial encoding:

Data Source

PatentEP3972746B1Sensors and method for generating spatially coded sound fields through sound-emitting apertures having a spatially varying frequency and bandwidth
Publication Date: 2024.04.17 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP3972746B1 patent drawingFigure 1
  • EP3972746B1 patent drawingFigure 2a~2c
  • EP3972746B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a transducer for generating and/or receiving a spatially structured sound field, comprising: an overall aperture (10) that generates and/or receives the sound field, wherein the overall aperture comprises a plurality of sub-apertures (12, 14, 16, 18), wherein each of the sub-apertures is configured to receive and/or generate ultrasound having a specific frequency spectrum, wherein the specific frequency spectra of at least two of the sub-apertures differ, and wherein all of the sub-apertures of the overall aperture are connected to the same electronic actuation channel.