Development of a real-time, high-frequency ultrasound digital beamformer for high-frequency linear array transducers

• Published in: IEEE transactions on ultrasonics, ferroelectrics, and frequency control Vol. 53; no. 2; pp. 317 - 323
• Main Authors: Chang-Hong Hu, Xiao-Chen Xu, Cannata, J.M., Yen, J.T., Shung, K.K.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-02-2006; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Acoustic signal processing; Acoustics; Arrays; Biological and medical sciences; Computer Systems; Computer-Aided Design; Delay; Digital; Equipment Design; Equipment Failure Analysis; Exact sciences and technology; Field programmable gate arrays; Filters; Fundamental areas of phenomenology (including applications); General equipment and techniques; Image Enhancement - instrumentation; Image Enhancement - methods; Image Interpretation, Computer-Assisted - instrumentation; Image Interpretation, Computer-Assisted - methods; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Investigative techniques, diagnostic techniques (general aspects); Medical sciences; Miscellaneous. Technology; Noise levels; Phantoms, Imaging; Physics; Radio frequency; Real time; Reproducibility of Results; RF signals; Sampling methods; Sensitivity and Specificity; Signal Processing, Computer-Assisted - instrumentation; Transducers; Ultrasonic imaging; Ultrasonic investigative techniques; Ultrasonic transducer arrays; Ultrasonic transducers; Ultrasonics, quantum acoustics, and physical effects of sound; Ultrasonography - instrumentation; Ultrasonography - methods; Wire; Human; Time frequency domain method; fractional delay filters; Linear array; Rabbit; Field programmable gate array; Lagomorpha; Radiofrequency; Real time; Beam forming; Eye; Vertebrata; Mammalia; Linear antenna; Signal delay; Acoustic antenna; Ophthalmology; Sampling; High frequency; Acoustic image; Ultrasound; Transducer network
• ISSN: 0885-3010; 1525-8955
• DOI: 10.1109/TUFFC.2006.1593370

A real-time digital beamformer for high-frequency ( >20 MHz) linear ultrasonic arrays has been developed. The system can handle up to 64-element linear array transducers and excite 16 channels and receive simultaneously at 100 MHz sampling frequency with 8-bit precision. Radio frequency (RF) signals are digitized, delayed, and summed through a real-time digital beamformer, which is implanted using a field programmable gate array (FPGA). Using fractional delay filters, fine delays as small as 2 ns can be implemented. A frame rate of 30 frames per second is achieved. Wire phantom (20 /spl mu/m tungsten) images were obtained and -6 dB axial and lateral widths were measured. The results showed that, using a 30 MHz, 48-element array with a pitch of 100 /spl mu/m produced a -6 dB width of 68 /spl mu/m in the axial and 370 /spl mu/m in the lateral direction at 6.4 mm range. Images from an excised rabbit eye sample also were acquired, and fine anatomical structures, such as the cornea and lens, were resolved.