Design And Implementation Of Automatic Needle Deflecting System For Medical Use

In recent years,the incidence of cancer in superficial organs such as thyroid and mammary gland is higher and higher,and the accurate diagnosis of cancer is the focus of researchers.In the current superficial organs such as thyroid,breast biopsy in the operation,mostly thanks to the doctor’s experience in vitro image take cell biopsy guided by manual puncture,puncture accuracy is not high,it’s easy to have a piercing operation failed.This article in view of the current superficial organs such as thyroid,breast biopsy system was improved,using automatic biopsy system instead of manual biopsy,namely robot assisted percutaneous puncture cells in biopsy.Compared with manual puncture,automatic puncture biopsy system has the advantages of accurate puncture path planning,automatic needle insertion and puncture accuracy,while reducing the influence of human factors.The automatic biopsy system will be more and more valuable in future puncture operations.The automatic biopsy system is divided into doppler ultrasound imaging,needle deflection and needle into the needle three main parts,the main content of the thesis is to automatic biopsy needle deflection part to carry on the design of the system.First introduced the superficial organs such as thyroid,breast automatic biopsy system research background and development situation at home and abroad,then expounds the related principle of automatic biopsy system,gives the overall structure of the puncture needle deflection system,then,the paper analyzes and designs the software and hardware platform of the needle deflector system,and first realizes the design of the FPGA minimum system in the hardware circuit(including the clock module,reset module,power supply module and download circuit module design),and also on the FPGA function of peripheral circuit design(including communicate with PC serial port circuit,level conversion circuit and AD sampling circuit,etc.).At the same time,the incremental PID controller is used to design the PID controller,and the peripheral components of FPGA are connected together,and the deflection of the puncture needle is controlled by closed-loop.In the software platform built on the upper computer platform and the lower computer platform,the next computer is designed and developed with Quartus Ⅱ 15.0 software,hardware implementation using Verilog HDL language serial port receiving module,stepper motor driver module and sampling clock module;The upper computer design USES the LabVIEW virtual instrument platform for development,realizes the Angle control parameters of the downward position machine transmission Angle and receives the transmitting Angle data from the lower computer,and displays the Angle data for display and monitoring.In the end,the PID controller and stepping motor module in the needle deflector system are simulated and verified by Modelsim,and the accuracy of the Angle deflection of the puncture needle is tested,test results show that the Angle of deflection errors are within the requirements of 1°.The design of the automatic biopsy system is of great theoretical significance and clinical value in promoting the development of superficial organ puncture biopsy technique.