Ultrasound Transducer Continuous Vibration for Shear Wave Elastography

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current ultrasound elastography methods face limitations in penetration depth and require high-end scanners due to weak shear waves generated by ultrasound radiation force, and are cumbersome for continuous measurement, especially in clinical settings where single-handed operation is necessary.

Innovation Solution

A method utilizing continuous axial vibration of the ultrasound transducer to induce shear waves, with correction techniques such as mean subtraction, k-space filtering, and local frequency estimation to remove motion artifacts, enabling real-time, continuous measurement of tissue mechanical properties without the need for additional vibration sources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If ultrasound radiation force with long duration push beam is used to generate shear waves, then tissue mechanical properties can be measured, but shear waves are very weak and penetration depth is limited

Engineering Contradiction:
Improvetissue mechanical properties measurementVSAvoidpenetration depth
Core Design Contradiction:
Measurement precisionVSLength of stationary object

Solution Approach 1:

The patent applies mechanical vibration by directly vibrating the ultrasound transducer at specific frequencies to generate shear waves in tissue, replacing the ultrasound radiation force method. This mechanical vibration approach produces stronger shear waves with better penetration depth while maintaining measurement precision of tissue mechanical properties.

Inventive Principle:
Principle #18Mechanical vibration

2Measurement precision

If push beam transmits hundreds of ultrasound cycles at high voltage, then shear waves are generated, but transmit circuit and transducer are very demanding

Engineering Contradiction:
Improveshear wave generationVSAvoidtransmit circuit capacity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the complex ultrasound radiation force system (requiring high voltage push beams and powerful transmit circuits) with a simpler mechanical vibration system applied directly to the transducer. This substitution generates the necessary shear waves without demanding high-end scanner hardware.

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

3Object-affected harmful factors

If updating frequency for continuous measurement is kept low below 1 Hz, then excessive heating is prevented, but it is difficult to find lesions with abnormal stiffness

Engineering Contradiction:
Improvetissue heatingVSAvoidlesion detection accuracy
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The patent enables continuous vibration of the transducer to generate continuous shear waves in tissue, allowing for real-time or near-real-time elastography measurements. This continuous action maintains low updating frequency to prevent heating while improving lesion detection by continuously monitoring tissue stiffness changes.

Inventive Principle:
Principle #20Continuity of useful action

4Measurement precision

If handheld vibrator is positioned adjacent to ultrasound transducer, then continuous vibration and shear waves are generated, but operator must use both hands

Engineering Contradiction:
Improvecontinuous shear wave generationVSAvoidsingle-handed operation
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent merges the vibration source and ultrasound transducer into a single integrated unit by applying mechanical vibration directly to the transducer. This eliminates the need for a separate handheld vibrator, allowing the operator to use one hand to hold the transducer and the other to control the scanner, enabling single-handed operation while maintaining continuous shear wave generation.

Inventive Principle:
Principle #5Merging (Combining)

5Measurement precision

If crawling waves from two vibration sources are used, then elastography measurements are achieved, but extra fixtures are required

Engineering Contradiction:
Improveelastography measurementsVSAvoidvibration source fixtures
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the need for complex fixtures to hold multiple vibration sources by applying mechanical vibration directly to the ultrasound transducer itself. This simplifies the system to require no additional fixtures, making it suitable for clinical practice while maintaining elastography measurement capability.

Inventive Principle:
Principle #2Taking out (Extraction)

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 approach enhances the ability to non-invasively measure tissue mechanical properties in real-time, improving the detection of lesions and facilitating single-handed operation in clinical settings, while increasing the efficiency and accuracy of elastography measurements.

Implementation Method 1

continuous axial vibration of the ultrasound transducer to induce shear waves

Methodology Applied
Scientific EffectMechanical vibration: Vibration

Implementation Method 2

ultrasound elastography method that utilizes continuous vibration of an ultrasound transducer

Methodology Applied
Scientific EffectUltrasound: Ultrasound

Data Source

PatentEP3215018B1Method for ultrasound elastography through continuous vibration of an ultrasound transducer
Publication Date: 2023.12.06 MAYO FOUNDATION FOR MEDICAL EDUCATION & RESEARCH
  • EP3215018B1 patent drawingFigure 1
  • EP3215018B1 patent drawingFigure 2~3
  • EP3215018B1 patent drawingFigure 4~6

AI summary

A method for imaging an object by ultrasound elastography through continuous vibration of the ultrasound transducer is taught. An actuator directly in contact with the ultrasound transducer continuously vibrates the transducer in an axial direction, inducing shear waves in the tissue and allowing for real-time shear wave imaging. Axial motion of the transducer contaminates the shear wave images of the tissue, and must be suppressed. Therefore, several methods for correcting for shear wave artifact caused by the motion of the transducer are additionally taught.