Low-power receive electronics for a miniature real-time 3D ultrasound probe

Transesophageal echocardiography (TEE) involves the use of an ultrasound transducer mounted at the tip of an endoscope to make ultrasonic images of the human heart from the esophagus. In conventional TEE probes, each transducer element is wired-out by a micro-coaxial cable to an external imaging system. To obtain real-time three-dimensional images, however, a two-dimensional transducer array with more than 1000 elements is required. Direct wiring of so many elements through an endoscope is not feasible, so channel reduction should be performed locally. In this paper, we present an application-specific integrated circuit (ASIC) that includes low-noise amplifiers, programmable-gain amplifiers and micro-beamformer circuits that locally process and combine the signals received by sub-groups of the transducer array. Thus, an order-of-magnitude channel reduction is achieved. The acoustic characterization of the prototype ASIC with a co-integrated transducer array will be presented.