For tissue characterization, it is desirable to determine B/A using high-frequency transducers. Moreover, an accurate estimate of B/A at elevated frequencies (or at least the assumption of frequency independence of B/A) is required to evaluate the safety of high-frequency systems. However, common finite-amplitude approaches become increasingly inaccurate at high frequencies. In this article, a practical variation of the finite-amplitude method is proposed which combines experiments with numerical simulations of the Khokhlov–Zabolotskaya–Kuznetsov equation and can be used at elevated frequencies. The results at low frequencies show that the proposed approach is accurate with lower uncertainties compared with the finite-amplitude method because it avoids assumptions and approximations. The measured values of B/A versus frequency for water at 2.25–20 MHz show that there is no statistically significant variation in B/A values with frequency, and therefore the assumption of frequency independence of B/A is realistic.

对于组织表征，最好使用高频换能器来确定B / A。此外，在升高的频率下准确估计B / A（或至少假设B / A的频率独立性) 用于评估高频系统的安全性。然而，常见的有限幅度方法在高频下变得越来越不准确。在本文中，提出了有限幅度方法的实际变体，该方法将实验与 Khokhlov-Zabolotskaya-Kuznetsov 方程的数值模拟相结合，并且可以在更高的频率下使用。低频结果表明，与有限幅度方法相比，所提出的方法准确且不确定性更低，因为它避免了假设和近似。的测量值乙/阿与在2.25-20兆赫频率显示为水不存在统计学显著变化乙/甲值与频率，因此假设B / A的频率无关是现实的。