Design Of Cranial Micro-current Stimulation Instrument

As the pressure of our life and work become more and more fierce, the prevalence rate of all kinds of mental illness shows an increasing trend. By the research of Ministry of Health in 2013, there were more than one hundred million mental disorders in our country, of which 16 million were severe mental patients. Confronting the huge patients and limited medical resources, it’s quite urgent to decrease the occurrence of the mental disease and to give the patients rational therapies.Cranial Electrotherapy Stimulation introduces micro-current into brain directly to enhance alpha brain wave activity, and to increase the concentration of neurotransmitters,in order to cure mental illness. As it’s used to stimulate the brain directly, there is high demand for the precision, stability, and safety of the system.The micro-current stimulation system is based on chip LPC1768, including signal isolation and transmission circuit, micro-current control module, pulse detect module, expended communication module, channel select module. The system used 2 pieces of shift and sore busregisters to constitute 12 bits DA transfer, and photoelectric isolation to protect the signal. It will reach very high precision, the signal can transmit steadily, and it will have a good protection for the master control chip and human body. We designed the current control cuicuit by pisitive side adder and constant current source circuit, which can eliminate the influence of the load and provide high precision and high stability. And synchronous pulse detection module is designed to detect the width of the wave, which can protect our brain from oversize pulse.Using oscilloscope to detect stimulation wave, it shows that the wave satisfies the need of producing high-precision and stable wave. Next using EEG machine to detect the change of the brain wave before and after the stiulation, to verify the active influence of the micro-current stimulation. The circuit simulation and the actual test show that the system is workable and reliable.