Non-iterative ultrasonic CT temperature reconstruction method

Abstract

The invention discloses a non-iterative ultrasonic CT temperature reconstruction method which comprises the following steps of constructing a matrix equation of a reconstruction problem, constructing a cost equation, solving the cost equation by means of a non-minimal optimization method, and reconstructing temperature distribution according to acoustic velocity. The non-iterative ultrasonic CT temperature reconstruction method is advantageous in that the non-minimal optimization method is introduced innovatively; a traditional iterative algorithm is replaced by characteristic value and characteristic root calculation; and simple method, low calculation amount and high practicability are realized. By means of the non-iterative ultrasonic CT temperature reconstruction method, remote measurement for an air temperature can be realized and a temperature distribution image is reconstructed. Furthermore the non-iterative ultrasonic CT temperature reconstruction method can be widely used for noncontact measurement at aspects of medicine, industry, etc.

Description

technical field [0001] The invention relates to the technical field of ultrasonic CT reconstruction, in particular to a non-iterative ultrasonic CT temperature reconstruction method. Background technique [0002] CT technology is a technology that relies on emitted energy waves to scan the measured area to obtain the required information. Compared with traditional measurement techniques, CT technology does not cause interference to the measured area, and is an ideal non-destructive measurement method. [0003] Ultrasonic CT is a CT technology that uses ultrasonic waves as energy waves. Its basic principle is to transmit multiple beams of ultrasonic waves to pass through the measured medium. Due to the uneven distribution of target features in the measured medium, the speed of ultrasonic waves will Change accordingly. In this way, by measuring the outgoing ultrasonic waves, according to the propagation time of the ultrasonic waves, the distribution of the target features in...

AI Technical Summary

Problems solved by technology

The reconstruction error of the filtered back projection algorithm is greatly affected by the filter, and usually only a rough result can be obtained, which is not suitable for fine image reconstruction.

The iterative algorithm has higher definition, but the calculation is complicated and the speed is slightly slower. Different iterative algorithms have different sensitivities to measurement errors.

Algorithms based on solving matrix equations generally have a higher degree of reduction and faster speed, but the least squares method cannot handle the case where the number of paths is less than the number of pixels, and the resolution of the reconstructed image is limited

In addition, when the number of pixels and the number of paths in the measured area are relatively large, the system matrix is ​​very large, and the efficiency of matrix operation is greatly reduced

[0005] It should be noted that the propagation path of ultrasonic waves in the air is relatively complicated, and phenomena such as diffraction and refraction are relatively serious.

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