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Objective  To design the ophthalmological hi-frequency annular array ultrasonic
platform,and to realize the digital signal processing of ultrasound. Methods We designed
the annular array circuit of transmission and reception. The high frequency ultrasonic echo
signals were proceeded directly to make analog digital sampling with high resolution and
speed after amplification. After the signal digitization,we could accomplish a series of
signal disposals,such as beam formation,dynamic focusing,filtration,demodulation and
logarithm amplification by field-programmable gate array (FPGA). The amplified high
frequency echo signals were proceeded to sample the signals by analog to digital change
device,and deal with the digital signals by FPGA. Results The transverse resolution of the
ophthalmological hi-frequency annular array ultrasonic platform was 0.2mm,the lateral
resolution was 0.4mm,that satisfied the clinical requirement. Conclusions Annular array
digital ultrasonic imaging improved imaging resolution and detective rate of diseases.