FPGA design of an even power distributor for optoelectronic neural stimulation

In this paper we present a control methodology to smooth the power consumption for battery operated optoelectronic/optogenetic neural prostheses. Optogenetics is a gene therapy method which photosensitizes neurons. It is therefore possible using micro photonics to stimulate neural activity using short high intensity pulses of light. We have previously demonstrated that stimulation can be achieved with combined CMOSGallium Nitride optoelectronic systems. But as these systems have intensity control utilizing pulse width modulation, there is a scaling issue with power supply spikes if large numbers of LEDs are turned on simultaneously. This can lead to power supply inefficiency and intensity droop. We have therefore developed a smoothing methodology, which redistributes pulse width modulation patterns to smooth out power fluctuations.