VERY-HIGH-FREQUENCY ULTRASOUND ARRAYS FOR OPHTHALMOLOGY

描述（由申请人提供）：本研究的最终目的是通过为临床医生提供显著改善的整个前眼超声图像，改善眼部疾病和疾病的护理，包括青光眼，眼外伤和肿瘤，以及视力缺陷。该研究将先进的高频、高分辨率超声环形阵列换能器与新颖的数字信号处理概念相结合，旨在克服传统高频超声系统所达到的几个限制；例如，这些阵列将聚焦深度提高了10倍。该阵列以数字合成孔径模式操作，允许发射脉冲和接收回波信号的动态聚焦。动态聚焦允许眼睛前部的微观结构在整个组织深度内“聚焦”；目前，非常高的分辨率（30 μ m）只能在亚毫米焦深度下实现。该方案还使用数字频率均衡处理技术来改善聚焦波束和接收回波的空间均匀性；该技术为组织显微结构成像提供了均匀的灵敏度。合成孔径和频率均衡技术相结合，增强了数字增强轴向分辨率（优于25 μ m）的概念，用于角膜的生物识别分析和优越的图像细节。这些技术也用于改善斑点抑制和图像对比度，提供稳定的、特征的复杂显微结构片段的灰度图像，如睫状体和眼前肿瘤。所提出的方法允许近实时生成眼睛的二维图像。

DESCRIPTION (provided by applicant): The ultimate objective of this research is to improve the care of ocular diseases and disorders, including glaucoma, ocular trauma and tumors, and vision deficiencies by providing clinicians with dramatically improved ultrasonic images of the entire anterior eye. The proposed research combines advanced high frequency, high-resolution ultrasonic annular-array transducers with novel digital signal processing concepts specifically designed to overcome several limits that have been reached with conventional high-frequency ultrasound systems; for example, the arrays improve the depth of focus by a factor of 10. The arrays are operated in a digital synthetic-aperture mode that permits dynamic focusing of both transmitted pulses and received echo signals. The dynamic focusing permits the microstructure of the anterior of the eye to be "in focus" throughout the entire tissue depth; currently, very high resolution (30 mu m) is available only in sub-millimeter focal depths. The program also uses digital frequency-equalization processing techniques to improve the spatial uniformity of focused beams and received echoes; this technique provides uniform sensitivity for imaging tissue microstructure. Synthetic-aperture and frequency-equalization techniques are combined to potentiate concepts that digitally enhance axial resolution (to better than 25 mu m) for biometric assays of the cornea and superior image detail. These techniques are also used to improve speckle suppression and image contrast, providing stable, characteristic grayscale images of complex microstructural segments e.g., the cilliary body and anterior ocular tumors. The proposed methods permit near real-time generation of 2-D images of the eye. To reach its goals, the program combines thorough digital simulations and transducer design, transduce fabrication, integrated digital processing and display, and laboratory testing. Concepts are validated and refined using scans of in-vitro porcine eyes and in-vivo rabbit eyes.