APPLICATIONS OF AIR-COUPLED ULTRASOUND BASED OCE SYSTEM IN BIOLOGICAL TISSUES

Based on the optical coherence tomography, dynamic optical coherence elastography (OCE) combined with different mechanical wave models has become one of the most popular elastography imaging techniques among researchers, with fundamental implications for quantitative, nondestructive, high-resolution and high-speed biomechanical characterization of biological tissues. Currently, OCE based on mechanical wave theory has led to three main technical components: (1) new methods to excite biological tissues to generate mechanical waves; (2) advanced theoretical analysis and numerical modeling to understand the propagation behavior of novel mechanical waves under complex boundary conditions; and (3) development of novel imaging techniques for nondestructive, non-contact, high-speed, high-resolution quantitative detection of biomechanical properties in two and three dimensions. These breakthroughs have facilitated research advances in basic science problems, optimized ways to diagnose diseases and monitor treatments in biological tissue medicine, and preliminary attempts have been made to conduct clinical trials and translational research to make wave-based OCE techniques clinically useful. This work presents the basic principles, detection methods and advanced techniques and applications of OCE technology using air-coupled ultrasound transducers. Recent advances in our developed air-coupled OCE technology in the fields of ophthalmology and brain science are demonstrated. Finally, the current challenges and future research directions of the OCE technique are discussed, as well as clinical translation.