Application Cases

Experiment Name: Application of Power Amplifier in Magnetoacoustic Imaging Method Based on Low-Frequency Magnetic Excitation and Active Ultrasonic Detection

Experimental Equipment: Signal generator, ATA-3090 power amplifier, ultrasonic probe, Helmholtz coil, data acquisition platform

Experimental Content:
To detect early-stage malignant tumors, this experiment proposes a magnetoacoustic imaging method based on low-frequency magnetic excitation and active ultrasonic detection. Color Doppler imaging technology is introduced to detect tissue vibrations caused by Lorentz forces. Active detection allows the use of low-frequency signals as excitation, significantly improving energy conversion efficiency.

Experimental Procedure:

1. Construction of the Experimental Platform:

An arbitrary waveform generator was used to produce an excitation signal, which was amplified by the power amplifier and input into the coil to generate an excitation magnetic field. Simultaneously, a phantom was placed within the excitation magnetic field, and a static magnetic field was applied externally in the same direction. Under the influence of the excitation magnetic field, induced eddy currents were generated at the boundaries of regions with conductivity differences within the phantom. These eddy currents were further subjected to Lorentz forces in the static magnetic field, causing vibrations in the surrounding tissue.

Figure: Physical Diagram of the Experimental Setup

2.Preparation of Experimental Phantoms and Shear Wave Excitation Experiments Combined with Simulation Phantoms:

Experimental Results:

1. Velocity variation curves over time at different points in the blank phantom velocity map.

2.Velocity variation curves over time at different points in the copper-embedded phantom velocity map.

Experimental Conclusion:
By comparing the experimental results of the copper-embedded phantom and the blank phantom in the new magnetoacoustic platform, we further validated the simulation results and observed the shear wave propagation process predicted by the simulations. This requires our experimental platform to provide a stronger magnetic field to obtain stronger magnetoacoustic signals. The velocity and morphological information during shear wave propagation will also aid in subsequent reconstruction of tissue conductivity or elasticity distributions.

Figure: ATA-3090C Power Amplifier Specifications and Parameters