Design And Implementation Of B-Mode Ultrasonic Imaging System Based On FPGA

Portable B-Mode Ultrasonic Diagnostic Apparatus has many advantages such as non-invasive, easy to operate, relatively inexpensive, It has been used more and more widely in clinical diagnosis.It incorporates many important subjects, such as ultrasonic,microelectronics, computer technology, mechanical design & manufacture, biomedical engineering, etc. The significance of this research is that it can improve clinical diagnostic capabilities and promote the development of our nation's health care.Portable B-Mode Ultrasonic Diagnostic Apparatus is made up of four parts, Human-Computer Interaction System, Probes, Imaging System and Display Systems. The basic process is: Firstly, Human-computer Interaction System receiver the commands which is send by the keyboard or mouse, then the Imaging System According with the commands to control the Probe transmitting the ultrasound signal, the imaging System then receivers and processes the Ultrasonic echo signal and synthetics the images,finally, through Display system display image.Imaging System as a core part for The portable B- Mode Ultrasound Diagnostic will have a decisive impact for the image quality . But The Imaging Systems of the Portable B-Mode Ultrasound Diagnostics developed several years ago have three shortages.The first is that they used the single-chip to control the stepper motor, so that the control accuracies are not high, which resultes in inaccurate sample of Image Synthesis System; The second is that the Digital Scan Conversion Algorithms are so rough that lead to the resolution of Ultrasound Images are not high. Finally,it is that the microprocessors used in these systerms mainly are 8 bit C51 signle chips,which are not keep up the measuring speed and have difficulty in development and expansibility.We developed a solutions for Ultrasound Imaging System Based on FPGA . Firstly, we used EP2C5Q208C8 chip of Altera's to subdivise the Step angle of the stepper motor's, so that more uniform motor rotation to improve the accuracy of the sampling. Secondly,proposed and adopted DSTI-ULA algorithm (Uniform Ladder Algorithm based on Double Sample and Trilinear Interpotation) in the FPGA to achieve the Digital Scan Conversion, which increases the image resolution; Finally,we used S3C2410-AL chip as the CPU chip for Human-computer Interaction System, which improves the measurement speed and system scalability.The author has designed and made the hardware circuits of the Portable B-Mode Ultrasonic Diagnostic Apparatus, and written software. From the experiment result, it was concluded that the Portable B-Mode Ultrasonic Diagnostic Apparatus designed in this research, which has high image resolution, high measurement speed, small size and easy operation.It can be play a role in the field operations and emergency ,such as earthquakes and floods, also it can be used to Diagnose related diseases at some rural clinics.