کنفرانس مهندسی برق ایران

صفحه اصلی / سی و سومین کنفرانس بین المللی مهندسی برق

Design of a Retinal Prosthesis Circuit With In-pixel Edge Detection Capability

نویسندگان :

Zahra Bonesbordi¹ Sayed Masoud Sayedi²

1- دانشگاه صنعتی اصفهان 2- دانشگاه صنعتی اصفهان

کلمات کلیدی :

Subretinal chip،Bipolar stimulation،CMOS image sensor،Edge detection،In-pixel image processing،Electrodes time-sharing،Local charge return،Time-based image processing

چکیده :

Abstract— Brain-machine interfaces (BMIs) enable the control of devices and restoration of neural activity by connecting directly to the nervous system. Retinal prosthesis chips offer a means of restoring partial vision in blind individuals by electrically stimulating neurons. This paper introduces a subretinal prosthesis circuit designed and simulated using 0.18μm CMOS technology. The circuit includes a sensor and a biphasic stimulator capable of generating retinal stimuli proportional to incident light at a voltage of 1V. In the sensor section, time-based photodiode sensing is employed to enhance its dynamic range. For image processing, the chip incorporates a pulse width comparator circuit. To enhance image clarity and minimize current leakage, a local charge return method based on bipolar stimulation is employed. Additionally, the design optimizes power efficiency through electrode sharing and a sequential control scheme, generating all necessary control signals internally. The circuit demonstrates a dynamic range of 30 dB with sensor power consumption as low as 1.18 nW per pixel.