The Circuit Design for a Transient Elastography System and Its Improvement Design

Elastography is an emerging ultrasonic imaging technique; it has a broad clinical application for tissue parameter estimation. We designed a real-time system to measure tissue stiffness information non-invasively based on transient elastography. The system performance mainly depends on the circuit design before the Analog-to-Digital Converter (A/D), especially the preamplifier part which is very sensitive to the noise. How to improve the signal-to-noise (SNR) is the key factor for the system design. In this paper, the Time Gain Control (TGC) design is discussed as an example of the circuit design. Displacement tracking algorithm based on correlation techniques and differentiation are applied to Radio frequency (RF) signals from tissues mimicking phantom and in vivo experiments; the young´s modulus of the tissue is estimated from the strain images. The influences of the SNR to the strain image quality are discussed. At the end, an improvement based on the AD9272 is proposed.