Prosthetic vision simulating system and its application based on retinal prosthesis

Retinal prosthesis provides a promising solution for retinitis pigmentosa (RP) and aged-related macular degeneration (AMD), which are the two major retinal degenerative diseases that cause a loss of vision. Clinical trials reported different irregular characteristics of phosphene map elicited by retinal prosthesis including irregular shaped phosphene, distorted phosphene array and dropout phenomenon. Psychological experiments under simulated prosthetic vision can be carried out to evaluate the ability of performing daily activities for prosthesis wearers. A prosthetic vision simulating system for retinal prosthesis is established based on a digital signal processor (DSP) TMS320DM642. In this system, external images captured by a microcamera are processed on the DSP and the simulation results are presented in a head-mounted display (HMD) after several image processing steps. Mathematic models are used to create phosphene maps with irregular characteristics including irregular shaped phosphene, distortion and dropout. This system can achieve a processing speed of 24 frames per second which can meet the requirement of the real-time processing. The portability and the real-time processing ability allow extensive psychological experiments to be conducted based on this system.