| The Sonic Window is a low-cost, pocket-sized medical ultrasound device currently under development at the University of Virginia. The long-term concept involves integrating a 2D transducer array, custom integrated circuitry, a digital signal processor and an LCD into a compact, battery-powered unit the size of a cell phone. It is envisioned as a widely available, easy to use device suitable for users with little or no prior ultrasound experience who would greatly benefit from using ultrasound to guide routine intervention or provide rapid diagnosis crucial to patient survival. As such, the Sonic Window will not compete with state-of-the-art medical ultrasound systems with respect to image quality or flexibility, but must surpass them with respect to ease of use, cost, and portability. Potential applications of the Sonic Window include guiding needle and catheter insertion, locating foreign bodies, identifying internal bleeding, and supporting routine physical examination. This dissertation work focuses on the receive electronics integrated circuit (IC) design for the Sonic Window.;A custom IC was designed consisting of 64 front-end receive channels composed of a novel transmit protection circuit, a differential low-noise preamplifier, and a transconductance output buffer. Sixteen of these ICs were incorporated into a 1,024-channel experimental ultrasound system serving as the first-generation (Gen1) system prototype of the Sonic Window. It consisted of a 32x32-element 2D transducer array, a PCB containing the front-end ICs, and a PC executing beamforming in software. The ability to form pulse-echo images with the Gen1 system provided first-order confirmation of the transducer, receive electronics, and beamforming approaches.;A second IC was designed consisting of an array of 300 full receive channels at a pitch of 200 μm x 275 μm. Each receive channel contains a protection circuit, a preamplifier, a tunable bandpass filter, a sampler bank, an analog-to-digital converter, and static digital memory. This IC was designed to form the core of a 3,600-channel receive electronics IC (REIC) array constructed by flip-chip attaching 12 bare die to a custom-designed flex circuit interconnect substrate designed to interface with a 60x60 2D transducer array. The REIC array is capable of real-time C-scan image formation and battery-powered operation. |
