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，改善眼部疾病和病症的护理，包括青光眼、眼外伤和肿瘤以及视力缺陷。拟议的研究将先进的高频，高分辨率超声环形阵列换能器与新的数字信号处理概念相结合，专门设计用于克服传统高频超声系统已经达到的几个限制;例如，阵列将焦点深度提高了10倍。该阵列在数字合成孔径模式下工作，该模式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结构在整个组织深度上“聚焦”;目前，仅在亚毫米焦深中可获得非常高的分辨率（30 μ m）。该计划还使用数字频率均衡处理技术，以提高聚焦光束和接收到的回波的空间均匀性，这种技术提供了均匀的灵敏度成像组织的微观结构。合成孔径和频率均衡技术相结合，以加强数字化提高轴向分辨率（优于25 μ m）的角膜和上级图像细节的生物测定的概念。这些技术还用于改善散斑抑制和图像对比度，提供复杂微结构片段的稳定的特征灰度图像，睫状体和眼前部肿瘤。所提出的方法允许近实时生成的2-D图像的眼睛。 为了实现其目标，该计划结合了全面的数字仿真和传感器设计，数字制造，集成数字处理和显示以及实验室测试。使用体外猪眼和体内兔眼的扫描来验证和改进概念。

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.