VHF/UHF range bioultrasonic spectroscopy system and method

We developed the bioultrasonic spectroscopy system and method for doing ultrasonic tissue characterization studies in the VHF and UHF ranges. The system can determine the frequency characteristics of bulk acoustic properties of the sound velocity, attenuation, acoustic impedance, and density simultaneously by an ultrasonic transmission line comparison method using pure water as the reference, and using rf tone burst pulse signals. A biological tissue/liquid specimen is sandwiched between the parallel surfaces of buffer rods having ZnO piezoelectric film transducers on their opposite ends. Measurements are conducted with a typical thickness of 0.1 to 1 mm in the frequency range up to 700 MHz, and in the frequencies higher than 500 MHz, with a thin layer of specimen, several micrometers, operating in the multiple interference method. The system was applied for demonstration to measure the acoustic properties of bovine tissues, egg yolk and albumen, and aqueous solutions of biomacromolecules such as bovine hemoglobin and sugars in the frequency range 10 MHz to 1.6 GHz. The system and methodology will enable us to provide basic data for understanding the interaction of high-frequency ultrasonic waves with biological media and to make contributions to the establishment of the scanning acoustic microscope in the fields of biological and medical sciences.