Ultrasonic Blood Flow Vector Imaging Beyond PRF Aliasing Limits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ultrasonic blood flow imaging systems face aliasing issues when blood flow velocities exceed the maximum measurable velocity, limiting the accuracy of quantitative measurements due to the limitations of pulse repetition frequency and imaging depth.
Innovation Solution
The method involves transmitting ultrasonic waves at multiple angles with non-integer multiple pulse repetition frequencies to acquire multiple projection components of blood flow velocity vectors, which are then combined to determine the actual blood flow velocity vector, effectively increasing the maximum measurable velocity and improving measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pulse repetition frequency is increased to improve maximum measurable velocity, then measurement precision improves, but imaging depth is limited due to sound speed constraints
Solution Approach 1:
The patent dynamically adjusts the pulse repetition frequency based on the transmitting angle. For different transmitting angles, the system selects appropriate PRF values from multiple candidate frequencies, allowing the system to adaptively optimize between imaging depth and maximum measurable velocity rather than using a fixed PRF
Solution Approach 2:
The patent changes the pulse repetition frequency parameter according to the transmitting angle. By selecting from multiple candidate PRF values (where at least one is a non-integer multiple of others), the system optimizes the balance between imaging depth and measurable velocity range for each specific transmitting angle
2Measurement precision
If multiple transmitting angles are used for vector blood flow imaging, then measurement precision improves, but PRF must be lowered due to imaging depth limitations, increasing aliasing risk
Solution Approach 1:
The patent dynamically selects pulse repetition frequencies based on the specific transmitting angle being used. For each transmitting angle, the system chooses from multiple candidate PRF values, ensuring that the selected PRF is optimized for both imaging depth and velocity measurement range, thereby maintaining reliability across multiple angles
Solution Approach 2:
The patent changes the pulse repetition frequency parameter according to the transmitting angle. By using non-integer multiple relationships between different PRF values and selecting appropriate frequencies for each angle, the system maintains the ability to measure high velocities without aliasing while using multiple angles for accurate vector measurement
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 measurement accuracy of blood flow velocity vectors by allowing for a larger actual pulse repetition frequency, thereby overcoming aliasing and providing more precise velocity measurements.
Implementation Method 1
Ultrasonic blood flow imaging based on Doppler's principle
Data Source
AI summary
An ultrasonic blood flow imaging method includes: transmitting first, second and third ultrasonic waves to a to-be-measured blood flow position of a target object at a first transmitting angle to acquire a first projection component of a blood flow velocity vector, with a first pulse repetition frequency between the first ultrasonic waves and the second ultrasonic waves and a second pulse repetition frequency between the second ultrasonic waves and the third ultrasonic waves; transmitting fourth, fifth and sixth ultrasonic waves to the to-be-measured blood flow position at a second transmitting angle to acquire a second projection component of a blood flow velocity vector, with a third pulse repetition frequency between the fourth ultrasonic waves and the fifth ultrasonic waves and a fourth pulse repetition frequency between the fifth ultrasonic waves and the sixth ultrasonic waves.