光学仪器, 2019, 41 (4): 74, 网络出版: 2019-11-05
眼轴长度测量系统设计
Axial eye length measurement system design
摘要
眼轴长度与屈光不正、白内障等常见眼科疾病有密切关系, 精确测量眼轴长度对眼科疾病的预防及治疗具有重要的意义。为实现眼轴长度安全有效的光学测量, 入射光强度不能超过安全限度, 同时人眼眼底反射出来的光只有入射光的 10.3~10.4。为此基于光学方法的眼轴长度测量的弱光探测, 设计了一种基于外差干涉测量的眼轴长度测量系统。测量系统硬件部分采用 PIN光电二极管将弱光信号转化成易于处理的弱电信号, 同时设计一个低噪声、高性能的弱信号处理电路, 并选用 Max 10系列的 10M25SAE作为主控芯片处理信号; 软件部分采用 VHDL语言进行编程。实验结果表明, 该测量系统可以对眼轴长度实现有效且稳定的测量。
Abstract
The axial eye length is closely related to common ophthalmic diseases such as refractive error and cataract. Therefore, the accurate measurement of the axial eye length is of great significance for the prevention and treatment of ophthalmic diseases. Because the reflected light from the retina is just 10.3 -10.4 times of the incident light whose value cannot exceed the safety limit, axis eye length measurement based on optical method is a kind of weak signal detection. This paper designs a measurement system based on heterodyne interferometry. The system selects PIN photodiode to convert the weak light signal into current signal, designs a low-noise, high-performance weak signal processing circuit, and adopts the 10M25SAE of Max10 series as the main control chip to process signals as well. The experimental results show that the measurement system can achieve an effective and stable measurement of the axial eye length.
杨梅, 王成, 李丕丁, 张宇宁, 郑刚, 张大伟. 眼轴长度测量系统设计[J]. 光学仪器, 2019, 41(4): 74. YANG Mei, WANG Cheng, LI Piding, ZHANG Yuning, ZHENG Gang, ZHANG Dawei. Axial eye length measurement system design[J]. Optical Instruments, 2019, 41(4): 74.