Research Laboratory of Precision Machinery and Electronics, Tokyo Institute of Technology
Random medium, Backscattering coefficient, Tissue characterization, Nonlinear acoustic effect, Gated sine wave
It have known that the intensity of echoes scattered by a random medium can be evaluated quantitatively in term of a backscattering coefficient. Since ultrasonic pulse systems used in medical diagnostic and nondestructive testing display the scattering intensity of medium, it is important in Tissue Characterization to establish the method for measuring the backscattering coefficient. In this paper it is shown about the method for measuring the backscattering coefficient of a stratified homogeneous medium in a bath (it is called in vitro measurement of the backscattering coefficient). We have suggested the method for correcting the influence of beam pattern on for measuring the backscattering coefficient and showed the method for measuring the backscattering coefficient using a broad band pulse, but it was a point at issue to have much influence of nonlinear acoustic effect in the higher frequency range of the broad band. In this paper in vitro measurement of the backscattering coefficient has been accomplished by combining the method to correct the influence of beam pattern with a gated sine wave. Though this method are not suitable to in vivo measurement, it will be important on the development of ultrasonic signal processing technology since it can measure the standard value of the backscattering coefficient.