Research And Design Of Wireless Low-Power Brain Stimulator Based On Cortex-MO+

Brain stimulation technology is widely used in brain-machine interface,treatment of neurological disease and other research areas.The development of brain stimulator is aimed at small size,low power consumption and wireless communication capability.Currently the lack of wireless low-power stimulators seriously inhibits the development of research in brain science,due to the difficulty of balance between wireless communication and power consumption.Therefore,it’s important to develop a wireless low-power stimulator.Aiming at wireless low-power characteristic,a stimulator strategy which is centered on multi-power mode turn-off polling communication power management strategy(MPPS)is proposed based on bidirectional constant brain stimulator.The tasks and working status of the stimulator along with methods of conversion among different working status are well defined.Also the power consumption modes of each function module in different time periods are specified.And the corresponding power supply,MCU and wireless communication circuits are designed in the following way:changing the dual power supply to single power supply;using the multi-working mode Cortex-MO + chip as the main MCU;selecting nRF24L01 + with a low-power working mode as the wireless communication module.In addition,embedded softwares are designed according to the circuits and MPPS.The designed stimulator has the abilities of outputting bidirectional constant current,stimulus parameters adjustment,power switch control and other functions by wireless communication.The output waveform is normal,and the measured voltage and current waveforms in the rat brain electrical stimulation experiment are consistent with the simulation results.The stimulator has the following characteristics:30*26*19mm3 size,10.9g weight,≤2%current output error.The current characteristics are 35μA in standby status which means keeping standing by for 8 months,and 5.5mA in low frequency stimulation status(1-second stimulation interval)which means keeping working for 36h.The main performance is superior to that of the existing similar wireless stimulators.Stimulator prototypes have been successfully applied in rat navigation experiments and intracortical microstimulation experiments and relevant data has been obtained.Research results have great significance on long-term online neuroscience research such as animal robots,epilepsy.