Golay improvement of the robustness of mean scatterer spacing measurement with ultrasonic backscattering

Abstract

Mean scatterer spacing (MSS) estimated from ultrasonic backscattering is of valuable information for tissue characterization. However, low ultrasound frequency, sound attenuation, and diffuse scattering significantly disturb the current MSS measurement methods. The aim of this study is to improve MSS measurement with Coded Excitation (CE) enhanced cepstrum estimation. The study proposes a Golay code-based cepstrum estimation and uses an equivalent Faran cylinder model of cancellous bone. By solving the elastic wave equation, ultrasonic backscattering signals were obtained through simulations. The adopted ultrasonic excitation is 0.9 MHz and is coded with 4-bit complementary sequences, which is modulated by employing a sinusoidal signal. Also, white Gaussian noise of 60 dB, 55 dB, and 45 dB was added to the backscattering data to study the robustness of the proposed method. Simulation results show that the Golay-based method successfully improved ultrasound energy transmission into the tissue and effectively suppressed interference peaks while identifying the right peaks with permitted errors. In addition, the robustness against noise was enhanced.