Ultrasound Vibration Potential measurement techniques for imaging

Ultrasound Vibration Potential signals (UVP) are generated when an ultrasound wave traverses colloidal suspensions or ionic solutions and disturbs their electrical equilibrium. The potential can be measured as an electrical signal and provides information that can be used to determine characteristics of the sample. The reverse effect, where an electrical signal in a colloidal suspension generates an ultrasonic signal also occurs and is commonly termed the Electro Sonic Amplitude (ESA). Measured amplitudes of UVP signals are in the region of a few hundred nano-volts and micro-volts and therefore pose difficulties in obtaining consistent data. Low noise instrumentation and techniques are necessary to obtain reliable measurements. UVP techniques have already been used to measure sample characteristics in homogenous distributions. However the technique also shows a high contrast between different types of object samples and can be used as an imaging method. This work describes the initial instrumentation and sensing methods that have been developed for detecting UVP signals for the purpose of imaging applications and the results with laboratory phantoms. (C) 2010 Elsevier B.V. All rights reserved.