Development Of Low Intensity Transcranial Ultrasound Stimulation System And Analysis Of Neuron Response Data

As a functional disease,nervous system diseases seriously threaten human health,and no effective treatment has been found yet.Noninvasive neuromodulation techniques,such as transcranial magnetic stimulation and transcranial electrical stimulation,have shortcomings of inadequate depth of stimulation and low spatial resolution.Ultrasound stimulation,as a new non-invasive neuromodulation technology,has sufficient stimulation depth and good spatial resolution.However,there is no ultrasound stimulation system with adjustable multi-parameter transmission pulse and serial port control at the same time.In order to overcome this defect,a portable low intensity transcranial ultrasound stimulation system with adjustable parameters was developed,and the feasibility of the system was verified by the analysis of neuron response data.Firstly,a low-intensity transcranial ultrasound stimulation system was developed.Based on this system,an ultrasound biological stimulation platform was built and its performance parameters were analyzed and tested.The hardware circuit of the ultrasound stimulation system takes the FPGA as the control core,including the transmitting module circuit with adjustable excitation pulse and the logic control circuit module of the FPGA.The transmitter module includes MOS driver,flyback switching power supply circuit module and power amplifier module.The logic control module of the FPGA includes the power supply and clock module of the system and the chip of the FPGA.The software design mainly includes the logic software of the FPGA and the software design of the upper computer.The logic software of the FPGA is mainly responsible for adjusting the parameters of the excitation pulse of the ultrasound stimulation system.The FPGA communicates with the upper computer through the specified communication protocol and displays the information to be monitored on the PC,and we can adjust the parameters of the transmitted ultrasound signal by the FPGA through this protocol.The performance analysis of ultrasound biological stimulus platform include the theoretical calculation of the resolution of ultrasound stimulation signal,the focusing test of ultrasound stimulation signal and the measurement and calculation of the intensity of ultrasound stimulation.Secondly,the excitatory response data of neurons stimulated by low intensity transcranial ultrasound were obtained,and statistical analysis was carried out to verify the mechanism of opening and closing mechanical sensitive ion channels controlled by ultrasound.A method of brain tissue stimulation based on low intensity ultrasound was designed.The field potential and intracellular calcium concentration changes of neurons before and after ultrasound stimulation were taken as the measurement indexes of excitability of neurons by transcranial ultrasound stimulation,and the mechanism of action of transcranial ultrasound on excitability of neurons was revealed.Finally,the data of neuron growth and development stimulated by low intensity transcranial ultrasound were obtained,and the statistical analysis was carried out to verify the mechanism of intracellular calcium concentration control by ultrasound.A primary neuron stimulation method based on low intensity ultrasound was designed.The area,length,survival rate and number of neurites before and after stimulation were taken as the observation indexes,and the possibility of low intensity transcranial ultrasound stimulation affecting the growth and development of neurons was revealed.