2D Array Transducer Shear Wave Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current medical diagnostic ultrasound systems face limitations in measuring tissue stiffness due to limited effective depth of penetration, out-of-plane effects, and measurement errors caused by transducer motion, leading to reduced accuracy and diagnostic value in shear wave imaging.
Innovation Solution
A diagnostic ultrasonic imaging system utilizing a two-dimensional array transducer to transmit a two-dimensional push pulse as a sheet of energy, which generates a planar shear wavefront, and employs background tracking pulses to correct for motion artifacts, enhancing penetration depth and reducing out-of-plane effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a one dimensional array transducer is used to generate shear waves, then the device complexity is reduced, but the effective depth of penetration is limited due to weak coupling and safety limits on maximum power
Solution Approach 1:
The patent transitions from a one-dimensional array transducer to a two-dimensional array transducer configuration. This dimensional change enables the generation of planar shear wavefronts that propagate deeper into tissue, overcoming the penetration depth limitations of conventional 1-D arrays while maintaining manageable device complexity through systematic element arrangement and phasing.
2Ease of operation
If a fixed focus mechanical lens is used to control the push beam, then the ease of operation is improved, but out-of-plane effects cause measurement errors and reduce accuracy
Solution Approach 1:
The patent replaces the static fixed focus mechanical lens with a dynamic electronic focusing system using a two-dimensional array transducer. This allows the push beam to be electronically steered and focused at multiple depths without mechanical movement, eliminating out-of-plane effects while maintaining ease of operation through software-controlled beamforming.
Solution Approach 2:
The patent divides the transducer array into multiple independently controllable elements arranged in a two-dimensional grid. This segmentation enables precise electronic control of the push beam direction and focus depth, allowing the system to maintain accurate in-plane stimulation while suppressing out-of-plane effects that plague single-lens systems.
3Measurement precision
If bandpass filtering is applied to eliminate low frequency motion artifacts, then the measurement precision is improved, but the productivity is reduced due to loss of useful signal information
Solution Approach 1:
The patent converts the harmful effect of low-frequency motion artifacts into a beneficial separation strategy by using the known frequency characteristics of shear waves. Instead of blindly filtering out low frequencies, the system uses the fact that shear wave frequencies are distinct from physiological motion frequencies to apply targeted filtering that preserves useful signal while removing artifacts, maintaining both precision and productivity.
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 system achieves highly resolved image data for tissue motion and shear wave characteristics, improving measurement accuracy and reducing errors, thereby enhancing the diagnostic value of tissue stiffness assessments.
Implementation Method 1
the push pulse excitation is in the form of a sheet of energy... which generates a planar or semi-planar shear wavefront
Implementation Method 2
The measurement of such tiny motions is accomplished by tracking the reflections from local inhomogeneities in the tissue being studied
Implementation Method 3
Background tracking pulses are transmitted at a plurality of locations... which are used to correct for motion artifacts
Data Source
Figure 1
Figure 2a~2c
Figure 3~4
AI summary
An ultrasonic diagnostic imaging system for shear wave measurement transmits push pulses in the form of a sheet of energy. The sheet of energy produces a shear wavefront which is a plane wave, which does not suffer from the 1/R radial dissipation of push pulse force as does a conventional push pulse generated along a single push pulse vector. The sheet of energy can be planar, curved, or in some other two or three dimensional shape. A curved sheet of energy can produce a shear wave source which focuses into a thin line, which increases the resolution and sensitivity of the measuring techniques used to detect the shear wave effect.