Development of a retina implant for epiretinal ganglion cell stimulation for patients suffering from retinitis pigmentosa
This contribution describes the realization of microelectronic components for a retina implant system that will provide visual sensations to patients with photoreceptor degeneration by applying electrostimulation to the intact retinal ganglion cell layer. Our system consists of five major microelectronic components: three for the external retina encoder and two for the implanted retina stimulator, all shown in figure 1.1. The implantable active retina stimulator is built in CMOS technology and includes a highly flexible silicon structure carrying multi-electrode arrays, a programmable stimulation pulse generator, and the telemetry receiver for signal and power reception. The external retina-encoder consists of the corresponding power and data transmission unit, a signal processor for computing the so called receptive field function (RF-function, which emulates the basic functionality of the retinal layers), and the image sensor system which provides high dynamic range of more than seve n decades corresponding the performance of the human eye. The hardware and software development for the system has been accompanied by a parallel effort which includes extensive research on implantation, morphological, and electrophysiological behavior.