Multi-Vibrator Shear Wave Actuator for Directional Elastography
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Solution Overview
Problem
Existing shear wave elastography systems face limitations due to the need for specialized probe design and driving electronics, restricting their availability on most ultrasound imaging platforms. Additionally, known vibration actuators lack adaptive control to optimize shear wave directionality for effective tissue imaging.
Innovation Solution
A vibration actuator comprising a housing with multiple rotational vibrators arranged in a geometric configuration, an accelerometer, and a controller. This setup allows for the generation of vibration vectors with desired directional behaviors, enabling adaptive control to align shear wave motion with the ultrasound imaging beam.
Engineering Contradictions & Design Principles
Engineering 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 specialized probe design and driving electronics are required which limits availability
Solution Approach 1:
The patent replaces the acoustic push pulse mechanism with a mechanical vibration actuator that directly generates shear waves through mechanical vibration. This substitution eliminates the need for specialized high-power acoustic probes and complex driving electronics, making shear wave elastography available on standard ultrasound platforms.
Solution Approach 2:
The patent introduces a mechanical vibration actuator as an intermediary device that couples to the ultrasound probe. This actuator serves as a mediator between the ultrasound system and the tissue, generating shear waves mechanically rather than acoustically, thereby avoiding the need for specialized probe design.
2Adaptability or versatility
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 directionality
Solution Approach 1:
The patent divides the single motor system into multiple independent motor units, each capable of independent control. This segmentation allows each motor to control a specific flywheel, enabling independent adjustment of vibration directions and frequencies to optimize shear wave propagation along the ultrasound beam.
Solution Approach 2:
The patent implements dynamic control of the motor speeds and directions to adaptively adjust the vibration characteristics. By dynamically varying the rotational speeds and directions of multiple flywheels, the system can optimize the shear wave directionality in real-time based on tissue properties and imaging requirements.
3Adaptability or versatility
If flywheels rotate at the same speed in opposite directions, then x-direction vibratory forces are canceled resulting in y-direction vibration only, but the vibration direction cannot be optimized for different imaging orientations
Solution Approach 1:
The patent employs periodic variation in the rotational speeds and directions of the flywheels to generate vibration vectors that can be oriented in different directions. By periodically adjusting the phase and amplitude of the rotational motion, the system can optimize vibration directionality for different imaging orientations while maintaining the counter-rotation cancellation effect.
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 proposed solution enables shear wave elastography on a broader range of ultrasound platforms without the need for specialized probe design, while ensuring optimal shear wave directionality for enhanced imaging performance.
Implementation Method 1
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
Implementation Method 2
The accelerometer is 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
Data Source
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.