The Design Of The Front-end System Of Portable Ultrasound Color Doppler Imaging

Ultrasonic diagnosis technology is widely used in the diagnosis of medical diseases because of its features of noninvasive,non-invasive and real-time.The development of technology often conforms to the change of social demand.In recent years,the miniaturization of equipment has become a branch of the development of ultrasonic imaging equipment.The traditional ultrasonic imaging equipment has a large volume,poor portability and high development cost.Therefore,this paper designs a portable ultrasonic imaging front-end system.The main contents of this paper are as follows:(1)Designed the hardware circuit of ultrasonic imaging front-end system,and completed the drawing of circuit schematic diagram and PCB diagram.According to the required hardware resources,this paper chooses the FPGA with the chip model of EP4CE30F23C8 as the main control chip,and designs each module according to the function division,including the power supply module,the main controller module,the high-voltage pulse generation module,the array selector module,the transceiver isolation module and the ultrasonic echo receiving module.Four pieces of HV7331 chip are used to generate 16 channels of high voltage pulse output channel,and two pieces of AFE5805 analog front-end chip are used to receive 16 channels of echo signal.Each circuit module is built by integrated chip,which reduces the volume of front circuit to a certain extent.(2)Debug the hardware circuit and write the driver code of each module.First,complete the circuit debugging of the power module,the main controller module and other functional modules successively.Secondly,according to the control mode of each chip,SPI communication protocol was written to realize the read/write operation of the primary gateway chip HV2701 and the echo receiving chip AFE5805.Based on the I^2 C communication principle,the corresponding program was written to realize the control of the output voltage of the DAC081C085 chip for adjusting the voltage control attenuator.Finally,the functional test procedures of each module are sorted out.(3)In order to verify the effectiveness of each module program,simulation tests were carried out on the code of each module of the front-end system.The simulation platformwas Model Sim SE.Because AFE5805 chip output data in an LVDS way,based on FPGA and Quartus ? structures,an LVDS receiving IP core,the solution of an LVDS data string.(4)Test the front-end system,mainly test the high-voltage pulse generation,array selection,transceiver isolation and LVDS signal reception process in the front-end system.The test results show that each module meets the basic functional requirements.