A Two-Dimensional Circular Array Transducer for Endoscopic Ultrasound Imaging of Tube

Area of Science:

• Materials Science
• Engineering
• Physics

Background:

• Endoscopic ultrasound (EUS) is used for inspecting tubular structures in non-destructive testing.
• Conventional EUS transducers have fixed normal focusing beams, limiting imaging flexibility and inspection robustness, especially for planar reflectors.

Purpose of the Study:

• To develop a two-dimensional circular array (2-D CA) transducer for three-dimensional focusing in EUS.
• To enhance imaging flexibility and inspection robustness for non-destructive testing applications.

Main Methods:

• Fabrication and validation of a prototype 2-D CA transducer with a central frequency of 10.10 MHz.
• Implementation of an independent-dual-focusing beamforming scheme with delay laws in two orthogonal directions.
• Evaluation of imaging performance through immersion EUS inspection of a stainless-steel tube specimen.

Main Results:

• The 2-D CA demonstrated the capability of focusing in any direction, significantly enhancing EUS imaging flexibility.
• Successfully detected quasi-planar reflectors (ring grooves, flat bottom holes, longitudinal grooves) that are difficult for conventional EUS.
• Achieved a 26.12 dB higher signal-to-noise ratio and 40.37% lower quantitative characterization error compared to conventional EUS.

Conclusions:

• The developed 2-D CA transducer offers superior detection robustness and imaging flexibility for non-destructive testing.
• This technology enables novel EUS imaging modalities with potential applications in both medical imaging and non-destructive testing.