Color ultrasonic Doppler blood flow speed estimation arc tangent optimization algorithm

Abstract

The invention belongs to the technical field of ultrasonic inspection. The invention aims at providing a color ultrasonic Doppler blood flow speed estimation method which has less resource consumption and is accurate and reliable. The color ultrasonic Doppler blood flow speed estimation arc tangent optimization algorithm is characterized by comprising the following steps of: making an LUT (look-up table) table in an LUT method; looking up the LUT table as 0<=c<1; firstly calculating and then looking up the LUT table and finally outputting as 1<=c< infinity; and in a similar way, transforming arc tangent operation in a value range of -pi to pi of a blood flow mean velocity arc tangent function, wherein V is average blood flow speed; A is an imaginary part of a self correlation function; and B is a real part of the self correlation function. The invention is mainly applied to ultrasonic inspection blood flow speed estimation.

Description

technical field [0001] The invention belongs to the technical field of ultrasonic testing and ultrasonic testing instruments, in particular to an arctangent optimization algorithm for color ultrasonic Doppler blood flow velocity estimation. Background technique [0002] Blood flow velocity and its direction are the most basic and important parameters in color Doppler imaging of the blood flow system. In the color ultrasound Doppler system, the stray signals in the received signal (such as echoes reflected by muscle tissue and blood vessel wall) have serious interference to the blood flow signal that you want to use, so in order to improve the quality of color blood flow imaging, the It performs filtering suppression. The complex signal Zi(n)=Ii(n)+Qi(n) is synthesized from the Ii and Qi quadrature signals output by filtering, the autocorrelation function of the complex signal is calculated, and then the average blood flow velocity is calculated by the autocorrelation functi...

AI Technical Summary

Problems solved by technology

In order to solve the problem of too large volume, Basoglu et al. proposed a method of creating two LUTs (look-up table, look-up table), one of which includes the range of rapid changes of the arctangent function. This LUT has good quantification and is suitable for small The sensitivity to changes is better. Another LUT is aimed at the slow-changing range of the arctangent function. This non-linear LUT has a larger quantization step size, which effectively reduces the LUT volume, but this reduction is still not enough; Taylor's formula expansion method When the independent variable is less than 1, the convergence is relatively fast, but when the independent variable is greater than 1, the convergence is slow, requiring a large number of multipliers, consuming hardware resources, and FPGA is not easy to implement; the CORDIC fast algorithm finds the LUT table that has calculated the arctan2 result in advance, and then moves The result of the bit addition operation, the LUT table that needs to be formulated is also huge and difficult to implement

[0007] It can be seen that all of the above have the problem of large resource consumption

Images