Magnetic thermal sound imaging resistivity rebuilding method based on optimization iterative algorithm

Abstract

The invention provides a magnetic thermal sound imaging resistivity rebuilding method based on an optimization iterative algorithm. An exciting coil generates electromagnetic thermal sound signals on a conducting object, an ultrasonic transducer receives the electromagnetic thermal sound signals, the signals are processed through an ultrasonic signal processing and collecting sub system, and a control circuit controls the synchronization of a current excitation source, the ultrasonic transducer and the ultrasonic signal processing and collecting sub system. The ultrasonic transducer carries out fault circumference scanning on the electromagnetic thermal sound signals, electromagnetic ultrasonic signals on each fault circumference are obtained, and finally, the rebuilding of a resistivity image is realized through being combined with an image rebuilding algorithm. The resistivity image rebuilding method has the advantages that an objective function satisfying a thermal sound source, the resistivity, a primary magnetism loss position space component and a scalar potential space component is firstly defined, under the condition that the thermal sound source distribution is known, the scalar potential space component is solved according to the current continuity theorem, then, the scalar potential space component and the magnetism loss position space component are substituted into the objective function, and the resistivity distribution is rebuilt.

Description

technical field [0001] The invention relates to a resistivity reconstruction method, in particular to a magneto-thermoacoustic imaging resistivity reconstruction method based on an optimal iterative algorithm. Background technique [0002] At present, the sensitivity and spatial resolution of traditional electrical impedance imaging technology are not high, mainly because electrical impedance imaging usually uses electromagnetic waves with low frequency as excitation. Since the wavelength is much larger than the imaging object, the electromagnetic field detection contrast is high, but the resolution is low. Needless to say, a single field has its physical limitations. Therefore, multi-physics imaging technology has received more and more attention, that is, one physical field acts on biological tissue and converts it into another physical field for detection. One physical field provides resolution, and the other provides contrast. , achieving simultaneous improvements in co...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the deficiency that the existing magneto-thermoacoustic imaging method cannot provide the resistivity distribution, and propose a magneto-thermoacoustic imaging resistivity reconstruction method based on the optimal iterative algorithm. The present invention is based on the optimal iterative algorithm, which can Accurately reconstruct the resistivity of conductive objects

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