TY - JOUR
T1 - Phase velocity estimation technique based on adaptive beamforming for ultrasonic guided waves propagating along cortical long bones
AU - Okumura, Shigeaki
AU - Nguyen, Vu Hieu
AU - Taki, Hirofumi
AU - Haïat, Guillaume
AU - Naili, Salah
AU - Sato, Toru
N1 - Publisher Copyright:
© 2017 The Japan Society of Applied Physics.
PY - 2017/7
Y1 - 2017/7
N2 - The axial transmission technique, which is used to estimate the phase velocity of an ultrasonic guided wave propagating along cortical bone is a promising tool for bone quality assessment. Lamb waves are ultrasonic guided waves that consist of multiple modes. The number of existing modes and the signal-to-noise ratio required for phase velocity estimation depend on the frequency of the signal. Hence, we employ an adaptive beamforming technique with spatial averaging to control signal-to-noise ratio and resolution by situating subarrays within the full array. Because the determination of the optimal size for spatial averaging is difficult, we propose a new algorithm that does not require a specific size with a new falsephasevelocity rejection technique. Using a 2.0-mm-thick copper plate, the proposed method accurately estimates phase velocity with fitting errors of 0.26 and 1.3%, as shown by simulation and experimental results, respectively. The measurement frequency ranges are more than twice wider than those measured by the conventional method.
AB - The axial transmission technique, which is used to estimate the phase velocity of an ultrasonic guided wave propagating along cortical bone is a promising tool for bone quality assessment. Lamb waves are ultrasonic guided waves that consist of multiple modes. The number of existing modes and the signal-to-noise ratio required for phase velocity estimation depend on the frequency of the signal. Hence, we employ an adaptive beamforming technique with spatial averaging to control signal-to-noise ratio and resolution by situating subarrays within the full array. Because the determination of the optimal size for spatial averaging is difficult, we propose a new algorithm that does not require a specific size with a new falsephasevelocity rejection technique. Using a 2.0-mm-thick copper plate, the proposed method accurately estimates phase velocity with fitting errors of 0.26 and 1.3%, as shown by simulation and experimental results, respectively. The measurement frequency ranges are more than twice wider than those measured by the conventional method.
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U2 - 10.7567/JJAP.56.07JF06
DO - 10.7567/JJAP.56.07JF06
M3 - Article
AN - SCOPUS:85025109053
VL - 56
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 7
M1 - 07JF06
ER -