School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
Sensors (Basel). 2023 Feb 27;23(5):2635. doi: 10.3390/s23052635.
A method to enhance laser ultrasound (LUS) image reconstruction with the time-domain synthetic aperture focusing technique (T-SAFT) is presented, in which the acoustic velocity is extracted in situ with curve fitting. The operational principle is provided with the help of a numerical simulation, and the confirmation is provided experimentally. In these experiments, an all-optic LUS system was developed by using lasers for both excitation and detection of ultrasound. The acoustic velocity of a specimen was extracted in situ by fitting a hyperbolic curve to its B-scan image. The needle-like objects embedded within a polydimethylsiloxane (PDMS) block and a chicken breast have been successfully reconstructed using the extracted in situ acoustic velocity. Experimental results suggest that knowing the acoustic velocity in the T-SAFT process is important not only in finding the depth location of the target object but also for producing a high resolution image. This study is expected to pave the wave to the development and usage of all-optic LUS for bio-medical imaging.
提出了一种利用时域合成孔径聚焦技术（T-SAFT）增强激光超声（LUS）图像重建的方法，其中通过曲线拟合原位提取声速。数值模拟提供了操作原理的说明，实验验证了其可行性。在这些实验中，通过使用激光同时激发和检测超声波，开发了全光 LUS 系统。通过将双曲线拟合到其 B 扫描图像，原位提取样本的声速。成功地使用提取的原位声速重建了嵌入在聚二甲基硅氧烷（PDMS）块和鸡胸肉中的针状物体。实验结果表明，在 T-SAFT 过程中了解声速不仅对于找到目标物体的深度位置很重要，而且对于生成高分辨率图像也很重要。这项研究有望为生物医学成像的全光 LUS 的开发和使用铺平道路。
