Wideband 2-D Array Design Optimization With Fabrication Constraints for 3-D US Imaging.

Area of Science:

• Medical Imaging
• Acoustic Engineering
• Array Signal Processing

Background:

• Ultrasound (US) 2-D arrays enable 3-D imaging without probe movement, but require complex driving electronics.
• Microbeamforming is used in high-end scanners, but 2-D sparse arrays offer a cheaper, efficient alternative for 3-D US systems.
• Designing optimal sparse array layouts is critical for achieving adequate beam characteristics throughout the 3-D volume.

Purpose of the Study:

• To provide guidelines for designing 2-D sparse arrays using simulated annealing optimization.
• To develop an energy function for optimizing array layout based on multidepth 3-D beam pattern analysis.
• To demonstrate the selection of optimal element activation for efficient acoustic radiating performance.

Main Methods:

• Simulated annealing optimization algorithm applied to 2-D sparse array design.
• Development of a novel energy function incorporating multidepth 3-D beam pattern analysis.
• Tutorial example optimizing element activation for a 32x32 array at 3 MHz.

Main Results:

• The proposed method successfully identifies optimal element subsets for 2-D sparse arrays.
• An optimized 256-element sparse array demonstrated significantly lower sidelobe levels compared to reference arrays.
• The 256-element array achieved 5.7 dB and 10.3 dB lower sidelobe levels than 716-element and 1024-element reference arrays, respectively.

Conclusions:

• Simulated annealing with a multidepth 3-D beam pattern energy function is effective for designing high-performance 2-D sparse ultrasound arrays.
• Optimized sparse arrays offer a viable solution for cost-effective and efficient 3-D ultrasound imaging.
• The design methodology allows tailoring arrays to specific applications and fabrication constraints.