Research On Hand-held B-type Ultrasonic Diagnostic Instrument Based On FPGA

Compared with MRI,X-CT,and nuclear medical imaging,ultrasonography has the advantages of noninvasive,non-ionizing radiation,cost-effective and easy-to-use.Nowadays,ultrasound imaging is widely used in the medical diagnosis of blood vessels,eyes,heart and other organs.With the rapid developments of computer,microelectronics,and other technologies-especially high-performance FPGA,Hand-held B-type Ultrasonic Diagnostic Instrument(B-HHUDI)has been realized and gradually developed towards miniaturization,low power consumption,high resolution and diversity.But,B-HHUDI also faces technical problems such as resolution and power consumption due to the limitation of portability(size).In view of the conflict between resolution and power consumption,this paper mainly focuses on the following 3 aspects of work:(1)The deficiency of conventional beamformer(CB)and adaptive beamformer(AB)have been studied.The imaging resolution of CB is poor and the computation of AB based on Minimum Variance is complex.Therefore,Spatiotemporally Smoothed Sign Coherent Factor Adaptive beamformer(St S-SCFA)is formed to both improve the imaging resolution and reduce the power-consumption.The targets points and cysts phantom are simulated on the Field II simulation platform.(2)In dynamic focusing,Focus Delay Parameter Compression(FDPC)is proposed to reduce power consumption by lowering the usage capacity and access frequency of RAM.And in middle and far-field,the Signal-to-Noise Ratio of echo signal is improved by Dynamic Receiving Aperture Focusing(DRAF).(3)In the echo signal processing,because of high sampling and focusing precision,the interpolation filter based on Cascade Integrator Comb structure is studied.And in order to improve the computing speed of logarithmic compression,a parallel lookup table logarithm is proposed.Meanwhile,logarithms mentioned above are simulated by Questa Sim,and imaging experiment is carried out on the hardware platform of the Handheld B-type Ultrasonic Diagnostic Instrument Based on FPGA.In order to illustrate the imaging effect,the experimental imaging results are compared with the existing product results.Simulations and experiments show that St S-SCFA can suppress sidelobe,improve imaging resolution and reduce the power consumption;DRAF guarantees the SNR of middle and far-field echo;FDPC can also reduce the power consumption to increase its battery life.