一种高动态范围的视觉功能修复电路  

A High Dynamic Circuit for Visual Function Recovery

作　　者：孙康明[1,2] 袁祥辉[1] 孟丽娅[1] 饶程[1] 

机构地区：[1]重庆大学光电技术及系统教育部重点实验室,重庆400044 [2]重庆工商职业学院,重庆400052

出　　处：《传感技术学报》2009年第10期1387-1391,共5页Chinese Journal of Sensors and Actuators

基　　金：国家自然科学基金项目资助(30470469)"人工视网膜及其评估方法研究";国家自然科学基金项目资助(60702007)"红外焦平面阵列视网膜形态读出电路技术研究"

摘　　要：为帮助视网膜病变患者有效恢复视觉能力,提出了一种输出信号频率与入射光强度成比例的视觉功能修复电路。该电路由光电探测器、施密特触发器和充放电控制回路等构成。在为光电探测器建立起精确的PSPICE宏模型的基础上,利用标准的0.6μm CMOS工艺完成了电路的设计和特性模拟。电路具有像元面积小(2 100μm2/pixel)和功耗小(平均2.3μW/pixel)的特点,满足了视网膜电路高集成度和射频供给能源的要求。同时,新电路的动态范围达到了70 dB,是相似拓扑结构视网膜刺激电路的数十倍,因此更适合用于视网膜的功能修复。It is an effective solution to recover visual capabilities for patients of retinal pathologies by implanting a electronic device in their eyes. A new visual function recovery circuit, which generates electrical pulses with frequency proportional to the intensity of incident light, is proposed. The circuit is composed of photodiode, Schmitt trigger and charging and discharging unit. An accurate photodiode circuit macromodel is built for SPICE simulation and used in the design of the visual function recovery circuit. The circuit has several advantages, that is, small pixel size （2100 μm2/pixel）and low power consumption （average 2.3 9W/pixel）. It is suitable for high integration densities owing to its small pixel size and the power supply of the retinal chip can be implemented by RF power induction because of low power consumption. Experimental results in 0. 6 μm 2P2M CMOS process indicate that dynamic range of 70 dB, which is much more than that of the similar circuit for retinal prosthesis, can be obtained. And so the presented circuit is more suitable for visual function recovery.

关 键 词：视觉功能修复 高动态范围 光电二极管 施密特触发器 

分 类 号：TN36[电子电信—物理电子学]