Design Of A Portable Ultrasound Soft Tissue Backscattered Signal Spectrum Analyzer

Ultrasound is widely used in the medical and military fields because of its characteristics of good transmission direction,strong penetration and easy access to concentrated acoustic energy.Especially in the detection technology,ultrasonic detection is popularized in the field of medical diagnosis and treatment because of its non-destructive,non-invasive,simple operation and strong resolution.The important content in the field of medical ultrasound diagnosis and treatment includes the study of the transmission characteristics of human soft tissue and the measurement of ultrasound parameters.Changes in soft tissue lesions or functions will also change their ultrasonic characteristic parameters accordingly.Therefore,the soft tissue can be subjected to ultrasonic excitation,and the soft tissue backscatter signal can be received and processed.Through the spectral analysis of the backscattered signal of soft tissues,the composition and changes of tissues can be retrieved.Combine the knowledge of pathology and clinical medicine to make diagnosis and estimate of soft tissue.The tissue structure information carried by the ultrasound soft tissue backscatter signal can provide an important reference for the characterization and evaluation of the tissue health status.In this paper,based on the soft tissue ultrasonic transmission mechanism and the monitoring requirements of soft tissue changes,a portable ultrasonic soft tissue backscatter signal spectrum analyzer is designed to study the spectral characteristics of soft tissue ultrasonic backscatter signals during changes.This design is an embedded system based on FPGA,using NIOS soft core as the MCU of the system,controlling the designed ultrasonic transmitting and receiving circuit to process the excitation signal and the echo signal.Then through the hardware underlying module,the data is AD converted,cached and fast Fourier transformed,and finally the TFT screen display module is used for human-computer interaction.The software programming part includes the construction of FPGA-based NIOS soft core system,the use of hardware description language Verilog to write the underlying IP core control module and control pulse transmission module;and the preparation of embedded C based on ?c/os-? operating system.The hardware circuit design part includes the design of the driving amplifier circuit based on the transistor and the design of the push-pull amplifier circuit based on the transistor;the design of the control pulse amplifier circuit based on the MOS tube,and the design of the echo receiving processing circuit based on the logarithmic amplifier.Through the design and implementation of software and hardware,the functions of excitation,reception,processing,display and spectrum analysis of ultrasonic pulse signals are completed.The design of the portable ultrasonic soft tissue backscattering signal spectrum analyzer helps to monitor muscle tissue in a daily manner,promote the process of home medical treatment,improve people's daily life quality,and also has important support for research work on soft tissue performance changes value.