Optison ultrasonic beam analysis test sound field

Ontison ultrasonic beam analysis test system is based on the working principle of laser stripe photography, it is quite real-time photo recording of the sound field generated by the ultrasonic probe in the medium, dedicated to the acquisition of ultrasonic underwater.A separate system of corrugated image that can quickly and accurately measure sound fields at different times, with high spatial resolution rate, high time resolution and wide dynamic range can make three-dimensional acquired two-dimensional sound field data , when the system works in the self-triggered mode, you can roughly observe the beam shape, focus position, and other acoustic characteristics, this experiment uses a newly developed set to support 128 independent transmission channels.Ultrasound transmitting system performs excitation of the HIFU piezo ceramic probe. By acquiring the image, data of the OPtison sound field test system is processing it with MATLAB, the image is the beam shape of the probe at the physical focus point.The shape can be found that the probe is successfully focused at a single point. The distance from the focal spot to the bottom of the probe is approximately 43.5 mm.The result with the theoretical model is 42.9 mm with an error of approximately 0.6 mm. In the later experiments, this parameter is explored.Head positioning issues provide a strong support.

Acoustic intensity measurement system for hydrophone sound field is an evaluation.Acoustic output parameters are a common measurement system that can test a frequency range from 250 Hz to 60 MHz. The excitation system still uses the multi-channel therapeutic ultrasound Hifu beauty treatment to describe above. The HGL-0200 hydrophone has a measuring frequency range from 0.25 to 4OMHz, sensitivity reaches 45llV claw, and the maximum operating temperature is 50OC. The HGL series hydrophones have high sensitivity and wide frequency band, which can effectively reproduce sound waves. Therefore, a bullet-type hydrophone of the type HGL-0200 is selected as the receiving device.

The hydrophone is moved according to the preset method, and the yoz focal plane and xoy focal plane are scanned, and the spatial sound field distribution of the HIFU piezoelectric element under different deflection focusing is obtained.The data can be found that when the probe is in the geometric focus plane, the height of the emitted focus is within a range of the x-axis from the physical focus point, and the maximum intensity of grating lobe is lower than 10 dB; and the focus deviates from the physical focus point along the y-axis. When the distance is in the range of 8 mm, the maximum grating lobes are less than one odB. According to the data, the physical focus point is about 3mm. In addition, it can be found from the figure that the optimal operating frequency of the probe is 2.1MHz, and the space with the strongest negative sound pressure is the maximum of all frequencies to reach 2.9Mpa.