Gradient-Based K-Space Shear Wave Velocity Estimation

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Solution Overview

Problem

Current methods for estimating shear wave velocity in soft tissues are inaccurate due to attenuation, limiting the clinical utility of tissue viscoelasticity imaging.

Innovation Solution

A system and method using k-space analysis that includes an ultrasound transmitter and receiver to generate and acquire shear waves, transforming data into a spatial frequency domain to compute gradient data, which are then processed to estimate shear wave velocity and attenuation, enabling more accurate calculation of tissue complex modulus.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If k-space local maxima analysis is used to estimate wave velocity, then the method is simple and useful, but the accuracy of the estimates varies and is insufficient for accurate complex modulus estimation

Engineering Contradiction:

Improvewave velocity estimation accuracyVSAvoidcomplexity of velocity estimation method

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transforms the velocity estimation approach by changing the parameter being analyzed - instead of using local maxima positions directly, it uses the gradient (derivative) of the k-space data. This parameter transformation enables more accurate velocity estimation through zero-crossing detection, resolving the accuracy limitation while maintaining computational feasibility

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the simple peak-detection mechanical approach with a gradient-based analytical method. By substituting the direct maxima search with gradient computation and zero-crossing analysis, the system achieves higher measurement precision without proportionally increasing system complexity

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If traditional k-space analysis is used, then wave velocity can be estimated, but attenuation causes energy loss and amplitude decrease leading to inaccurate complex modulus estimates

Engineering Contradiction:

Improveaccuracy of complex modulus estimationVSAvoidwave energy attenuation in tissue

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent converts the harmful effect of attenuation into a beneficial feature by using the gradient magnitude in k-space. The attenuation information, which traditionally degrades signal quality, is transformed into useful data through gradient analysis, enabling accurate complex modulus estimation that accounts for both velocity and attenuation effects

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The gradient of k-space data serves as an intermediary that bridges the gap between raw wave data and accurate complex modulus estimation. This intermediary transformation allows the system to extract reliable velocity and attenuation information even in the presence of energy loss, resolving the reliability issue

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9918698B2System and method for gradient-based k-space search for shear wave velocity dispersion estimation

Publication Date: 2018.03.20 MAYO FOUNDATION FOR MEDICAL EDUCATION & RESEARCH

AI summary

Described here are systems and methods for ultrasound processes using shear wave attenuation and velocity derived from k-space analysis by analyzing spatial frequency domain data.