Crossed-array transducer for real-time 3D imaging

A crossed-array transducer for real-time three-dimensional imaging has been developed along with an accompanying transmit pulser and beamforming system. The system incorporates novel design features that address the unique constraints and requirements imposed by the crossed-array construction. These developments include a 1-3 composite with radially apodized polarization; a bipolar ±100V pulser with variable frequency and delay control, and a low-impedance ground in the off-state; and a transmit beamformer with a computer interface to monitor and control the system. Experimental results demonstrate the system to have a 3dB beamwidth of 2mm at 60mm depth (f/1.4) and 4mm at 80mm depth (f/1.8). The beam-shape has excellent confinement along the focused axis, and the defocused orthogonal plane reaches a maximum intensity drop of 6dB over a 45° sector.