Testing and monitoring system for a first generation intracortical visual prosthesis device using Java, Labview and VGA / NTSC output

Hardware designed for a specific application presents a unique problem of testing it for accuracy and behavior. The visual prosthesis device designed in the Laboratory of Neural Prosthetic Research at IIT, (Chicago) uses an FPGA to capture images from a camera, performs image processing, and generates an instruction set which is sent on a radio frequency magnetic link to an implanted module in the visual cortex producing electrical currents in a group of intracortical electrodes. The design of this visual prosthesis device presents the problem of testing it both quantitatively and qualitatively, prior to implantation in a human. We can test the individual components of a visual prosthesis device using software simulations but the problem is to test it end to end. The problem is further complicated by the fact that the system is processing 50 frames/ second and generating data at a rate of 1.25 Mbits/sec. To evaluate all possible inputs and do an exhaustive test becomes a daunting task. In this paper we describe a method developed in our laboratory to easily and effectively test, and monitor, our system. Along with the test modules for our dedicated hardware, we have developed a secondary module as a requirement for visually monitoring the behavior of the system during non-human / human primate experiments, providing a means for estimating the cortical response and resultant visual perception. This system will also be used for human psychophysical experiments.