Design of high-frequency ultrasound grayscale blood flow imaging system based on field programmable gate array / 医疗卫生装备

ABSTRACT

Objective To develop a set of high-frequency ultrasound grayscale blood flow imaging system based on field programmable gate array (FPGA) to execute simultaneous imaging of superficial blood flow and tissues.Methods This system was mainly composed of an ultrasonic transducer,an ultrasonic transmission and receiving modules,imaging software in host computer and peripheral equipment.A PVDF transducer with the frequency between 20 and 50 MHz was used for the ultrasonic transducer.In transmission and receiving modules,the radio frequency echo signals were digitized by high-speed A/D.Then the digital signals were transmitted,added,filtered,demodulated,log amplified,double sampled,and lastly transferred to the host computer by USB interface for real-time display.Results A vascular 1 mm far form the surface of the hand skin was examined by this system.Four blood flow images were obtained in corresponding with four transmission frequencies.Conclusion Real-time superficial organ blood flow imaging is realized by this system.The solution has the architecture concise and clear,and lays an experimental foundationfor high-frequency ultrasound gray-scale blood flow imaging.