Directional Vibration Actuator for Shear Wave Elastography

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Solution Overview

Problem

Current shear wave elastography methods are limited by the need for specialized probe design and driving electronics, restricting their availability on standard ultrasound platforms, and lack adaptive control over vibration direction, which is essential for optimal tissue imaging.

Innovation Solution

A vibration actuator system comprising multiple rotational vibrators with independently controllable motors and an accelerometer, allowing for coordinated rotation to generate shear waves with desired directional behavior, enabling alignment with ultrasound imaging beams and efficient vibration alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a special acoustic push pulse is used for shear wave generation, then shear wave elastography can be implemented, but it creates special requirements on probe design and driving electronics, limiting availability to premium platforms

Engineering Contradiction:
Improveavailability of shear wave elastographyVSAvoidprobe design requirements
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces the acoustic push pulse method with a mechanical vibration source (electromagnetic driver) to generate shear waves. This substitution eliminates the need for special high-power acoustic transmission capabilities in the probe, allowing standard ultrasound probes to perform shear wave elastography. The mechanical vibration source directly contacts the tissue and generates shear waves through mechanical oscillation, bypassing the limitations of acoustic-based methods.

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

2Ease of operation

If a single motor with geared driver is used to rotate flywheels, then the device structure is simplified, but the vibration direction cannot be adaptively controlled to optimize shear wave measurement

Engineering Contradiction:
Improvevibration direction controlVSAvoidmotor and driver configuration
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent divides the single motor system into multiple independent electromagnetic drivers (e.g., three drivers arranged in a triangular pattern). Each driver can be independently controlled to generate vibration in specific directions. This segmentation allows the system to synthesize vibration in any desired direction by coordinating the motion of individual drivers, providing adaptive directional control while maintaining relatively simple device architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic control of vibration direction by independently adjusting the amplitude and phase of each electromagnetic driver. The system can adaptively change the vibration direction in real-time based on the imaging beam direction and tissue characteristics, optimizing shear wave measurement for different anatomical locations and imaging angles.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If multiple rotational vibrators with independent motors are used, then adaptive vibration direction control is achieved, but the device complexity increases

Engineering Contradiction:
Improvevibration direction adaptabilityVSAvoidnumber of motors and components
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple electromagnetic drivers into a single integrated vibration module that interfaces with the ultrasound probe. The drivers share common mounting structures, housing, and control electronics, merging their functions into a unified assembly. This approach achieves adaptive directional control through multiple independent actuators while minimizing overall device complexity through integration and shared components.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables shear wave elastography on a broader range of ultrasound platforms, improves vibration alignment with imaging beams, and achieves efficient, compact, and energy-efficient linear vibration generation.

Implementation Method 1

an accelerometer arranged to detect a vibration vector generated by at least two of the plurality of n rotational vibrators and generate an accelerometer output signal based on the detected vibration vector

Methodology Applied
Scientific EffectAccelerometer detection: Accelerometer

Implementation Method 2

Each rotational vibrator comprises an independently controllable motor having a drive shaft and an eccentric disk coupled to the drive shaft in a plane perpendicular to an axis of the drive shaft

Methodology Applied
Scientific EffectMechanical vibration: Vibration

Implementation Method 3

an eccentric disk coupled to the drive shaft in a plane perpendicular to an axis of the drive shaft

Methodology Applied
Scientific EffectEccentric rotation: Eccentric

Data Source

PatentEP4263076B1Vibration actuator for shear wave elastography, system and method
Publication Date: 2024.07.17 KONINKLIJKE PHILIPS NV
  • EP4263076B1 patent drawingFigure 1
  • EP4263076B1 patent drawingFigure 2
  • EP4263076B1 patent drawingFigure 3

AI summary

A vibration actuator (10) for mechanically generating a shear wave comprises a plurality of n rotational vibrators (141,142,143), an accelerometer (16), and a controller(18). The plurality of n rotational vibrators enables generation of a vibration vector with desired directional behavior selected from a plurality of vibration vectors (34,36,38) of different directional behaviors. Each rotational vibrator comprises an independently controllable motor (20) having a drive shaft (22) and an eccentric disk (24). The accelerometer is arranged to detect a vibration vector generated by at least two of the plurality of n rotational vibrators. The controller selectively controls a first set of two rotational vibrators to rotate respective eccentric disks in a first coordinated manner to produce a first vibration vector, and a second set of two rotational vibrators to rotate respective eccentric disks in a second coordinated manner to produce a second vibration vector, with different respective directional behaviors.