Constant Current Stimulation System Designed For Rat-Robot

Robotics animals based on BCI (Brain-Computer Interface) in many areas shows its advantages and bright future. Rat robot in China and abroad has more and research on it. Robot system stimulator is a very core part of rats.This paper presents a low-power constant-current stimulation system designed to make electrical stimulation in rat brain for behavior control. The goal of stimulator are: constant stimulation, stimulation intensity is precise, adjustable waveform, wireless communication, small size, light weight, low power consumption. Stimulation module was designed based on precision constant current source AD620. It can achieve positive and negative pulse output current. Frequency, pulse-width are adjustable. C8051F007based controller uses a CPU module that combines Bluetooth communication, the system has a high degree of integration. Power module is based on DC-DC power boost technology solutions to improve the efficiency of the battery. Embedded software design is based on state machine programming, effectively saving the microcontroller chip resource consumption, reducing the microcontroller operating frequency, further reducing power consumption.The results of multiple programs to reduce power consumption make stimulator has an average operating current of less than30mA, to meet the need of the experiment in a small volume80mAh lithium battery condition. Stimulation (including battery) weights12.7g and have a volume of34*25*14mm. Electrical performance tests shows that the output stimulator waveform, constant effect, power consumption meet the design requirements. A total of nine stimulator is produced, four of which were used in experimental brain-computer interface applications up to one year and still works well.Prototype designed to stimulate the pleasure district conducted in rats (MFB) and the stimulating effect result shows that1mA has the best results. Three rats were stimulated with different stimulus parameters and found that resistance decreases with stimulation of brain increases. Stimulator gained more than90%success rate in the rat experiments with eight lever arm maze test. Experiment and test results show that the stimulator performance meet the design requirements for rat brain-machine interface applications. Constant current stimulator provide accurate quantitative experimental platform for further scientific research. The stimulator has also been used in the field of robotics rats, rat epilepsy research model.