Design of a micro-beamformer for a 2D piezoelectric ultrasound transducer

This paper describes the design of a transesophageal probe using a matrix (2D array) ultrasonic transducer for 3D echocardiography. To obtain images with sufficient resolution, several thousand elements are required. To reduce the channel count from the transducer to the imaging system, it is necessary to include electronics close to the transducer and use smart signal processing for data reduction. A micro-beamforming method called pre-steering is proposed. All the groups have the same delay configuration, which will simplify the required electronics. For a correct design, delay steps and the maximum delay are of importance. Furthermore, the delay should be programmable for each direction. Simulations are performed to investigate the effect of pre-steering on the received field. The delay and sum operations are realized by an integrated circuit. Simulations show that, for the micro-beamformer of a matrix transducer, the pre-steering approach is an effective method to reduce the complexity of the electronics and the channel count, while maintaining an adequate receive field.