Research On The Generation And Control Device Of Low-intensity Focused Ultrasound Signal

Nervous system diseases have been threatening human health for a long time and have brought great troubles to human daily life.At present,the treatment of nervous system diseases mainly includes drug therapy and nerve regulation,for patients with poor drug treatment effect or drug resistance,such as drug-refractory epilepsy,transcranial magnetic stimulation and transcranial electrical stimulation provide a non-invasive treatment for patients.At present,transcranial electric and magnetic fields still have certain shortcomings in spatial focusing characteristics and stimulation depth,low-intensity transcranial focused ultrasound stimulation can realize the regulation of nerve tissue by focusing the ultrasonic mechanical energy into the skull.It has the advantages of good focus and depth of stimulation,so it has received widespread attention.Since the ultrasound frequency,intensity,pulse repetition time and other parameters directly affect the control effect,in order to meet the needs of low-intensity focused ultrasound neuromodulation research,in this subject,a transcranial ultrasound stimulation device with adjustable frequency,voltage,and pulse repetition time is designed,this device realizes continuous or pulsed ultrasound output,which is suitable for the needs of neuromodulation research.The low-intensity focused ultrasound control system designed in this subject is composed of a signal generator module,an ultrasound transmitter module,a software control module,and a power supply module.The signal generator module takes AD9106 as the core,which can output continuous and pulse mode sine wave signals with adjustable frequency and voltage amplitude.The module includes a Buck circuit,an I/V conversion circuit,and a low-pass filter circuit.The ultrasonic transmitter module is responsible for amplifying the power of the signal generated by the front-level signal generator module to achieve a voltage output of plus or minus25 volts.The power module uses dual switch forward topology as the main circuit of the power and UC3844 as the power control chip to output two voltage signals.The software control module uses Raspberry Pi as the main control board,use Python language programming to write control programs to the signal generator module,output signal with adjustable frequency and voltage amplitude,and drives the focused ultrasound transducer after power amplification.The experimental results show that the system designed in this subject has achieved the driving performance of low-intensity focused ultrasound,realized the ultrasonic with adjustable frequency,voltage and intensity,and basically met the needs of low-intensity focused transcranial ultrasound.