Integrated Circuits for Volumetric Ultrasound Imaging With 2-D CMUT Arrays

Abstract

Real-time volumetric ultrasound imaging systems require transmit and receive circuitry to generate ultrasound beams and process received echo signals. The complexity of building such a system is high due to requirement of the front-end electronics needing to be very close to the transducer. A large number of elements also need to be interfaced to the back-end system and image processing of a large dataset could affect the imaging volume rate. In this work, we present a 3-D imaging system using capacitive micromachined ultrasonic transducer (CMUT) technology that addresses many of the challenges in building such a system. We demonstrate two approaches in integrating the transducer and the front-end electronics. The transducer is a 5-MHz CMUT array with an 8 mm × 8 mm aperture size. The aperture consists of 1024 elements (32 × 32) with an element pitch of 250 μm. An integrated circuit (IC) consists of a transmit beamformer and receive circuitry to improve the noise performance of the overall system. The assembly was interfaced with an FPGA and a back-end system (comprising of a data acquisition system and PC). The FPGA provided the digital I/O signals for the IC and the back-end system was used to process the received RF echo data (from the IC) and reconstruct the volume image using a phased array imaging approach. Imaging experiments were performed using wire and spring targets, a ventricle model and a human prostrate. Real-time volumetric images were captured at 5 volumes per second and are presented in this paper.

Frequency‐modulated magneto‐acoustic detection and imaging

“…In order to detect these lower pressure levels at safe average SAR levels, averaging as well as long-term duty cycling may be necessary. In addition, optimized transducers, such as Capacitive Micromachined Ultrasound Transducers (CMUTs), and custom receiver electronics may be advantageous [19].…”

An FPGA Implementation of Resource-Optimized Dynamic Digital Beamformer for a Portable Ultrasound Imaging System

“…One-dimensional ultrasound transducer arrays are used to get 2D images, and two-dimensional transducer arrays have been applied to produce 3D ultrasound images [12][13][14]. The ultrasound produces images through the backscattering of the mechanical energy from boundaries through tissues.…”

A Scalable Organization of 2-D Ultrasonic Sensor Array

“…CMUT enables the frontend to be small with integrated circuits(IC) and many receive elements can be placed. So the high resolution front-end with many ultrasonic sensors is expected (4) . But, increase of cables to the back-end that processes a large number of dataset causes to degree improvement of resolution.…”