Acoustic Cavitation Detection Produced by Ultrasound in an Agarose-gel Phantom Analyzed with Frequencies Spectrogram

The application of ultrasound in medicine includes the detection of the functioning of the blood flow, in surgery and in the exploration with images of the interior of the human body. Acoustic cavitation has an important role in therapeutic and diagnostic applications in medicine. For specific cases, the acoustic cavitation has been presented as a booster of clinical applications in the opening of the Blood-Brain Barrier or the elimination of blood clots in blood vessels. In order to understand the behavior of this phenomenon, in this paper it is presented the elaboration of an agarose-gel phantom, the measurement of its properties and a proposal of experimental setup of transducers able to produce acoustic cavitation in the agarose-gel phantom with the processing of the signals detected employing spectrograms of frequencies. The results obtained showed the probability of appearance, the intensity, the duration and the frequencies in which the phenomenon of acoustic cavitation appear and show that when the power applied to the transducer increase, the parameters mentioned tend to increase as well being the highest power applied the level of power with the higher percentage in which the acoustic cavitation presents. Obtained results demonstrate that the appearance percentage of cavitation are less than 5% of the samples present the cavitation at low stimulating power, and near to 95% of the samples demonstrate the presence of the cavitation at maximum stimulation power applied.