Ultrasound transducer sensitivity in non linear parameter measurement

Abstract

We present a procedure for measurement of the non linear BIA parameter using a simple comparative method . A theoretical model of the measurement system is proposed. A function sensitivity of the system is derived in order to connect the electric and acoustic magnitudes. Thus the optimal conditions in order to avoid complex calculation of the transducers sensitivities were carried out. We showed that the sensitivity function of the measurement system can be kept close to the unit by making a good choice of the fundamental frequency. Indeed if the frequency of the source transducer is chosen less than the resonance frequency we can avoid determining the sensitivities. Measurements had been carried out to validate the procedure and the theoretical aspects.

Significance of accurate diffraction corrections for the second harmonic wave in determining the acoustic nonlinearity parameter

“…1(a) shows the results of using 10 expansion coefficients in the MGB model [Eq. (9)] to calculate the on-axis pressure amplitudes of the fundamental wave, and compares with the results calculated by the exact RS integral [Eq. (16)].…”

“…An exact integral expression exists for the linear field when both transmitter and receiver sizes are the same. 4,5 An approximate diffraction correction to the second harmonic wave was presented by several authors [7][8][9] based on the average velocity potential of Ingenito and Williams, 6 and used in later studies for estimating the nonlinearity parameter of solids and fluids. The plane wave assumption does not hold when it propagates through an attenuating medium.…”