Designs Of Interpolation Filter Based On FPGA Used In Ophthalmology Ultrasonography

The Ultrasonography diagnosis technology is safe, woundless, convenient, inexpensive, and its merits also consists of repetitive examining, high veracity in diagnosis, and has the better ability to distinguish parenchyma. Nowadays, it has become the first choice technology of contemporary medical imaging diagnosis. In recent years, with the rapid development of the digital signal processing, the hardware and software design capabilities, as well as the aspects of materials science and so on, the ophthalmology Ultrasonography has made great progress in some areas, special in digital ophthalmology Ultrasonography. Compared to abdominal Ultrasonography, the frequency of ophthalmology Ultrasonography is higher, more than 10 MHz. The sampling rate and precision of ADC (Analog-To-Digital conversion) make important impact on image clarity and accuracy at the final diagnosis. ADC device with High sampling rate and high-precision is costly and also may be limited at purchasing. But some companies still implement ophthalmology Ultrasonography imaging in use of ADC device with high sampling rate and have no better method. So, it's very important to present and apply effective arithmetic for interpolation (sampling rate increase) in digital ophthalmology Ultrasonography to get high-precision ultrasonic sampling data in used of an ADC with low sampling rate, low precision, low cost and purchasing easy.This paper has been started with the theory and design of filters for decimation (sampling rate decrease) and interpolation (sampling rate increase). At the same time, we also have made a brief introduction of the structure characteristics, the programming theory, and the design process of the Field Programmable Gate Array. On this basis, combined with the characteristics of high frequency Ophthalmology Ultrasound signal processing, we have designed FIR filters for interpolation based on FPGA. Lastly, by building some physical simulation model, the validity of each design in signal processing of the system has been validated. The designs have been successfully applied to digital ophthalmology Ultrasonography. These designs have good ability to process high frequency ultrasonic echo signals of ophthalmology in real time. It has reached design demands, and shows a good application prospect.