Abstract

The amplitude cancellation method that uses dual out-of-phase sources (a phased array system) can sensitively detect and locate small objects in turbid media. The balance of these two sources is crucial to the system’s detection sensitivity and accuracy. We describe a convenient method with which to adaptively calibrate the amplitudes of the two sources at each scanning position by use of low-frequency modulation of the intensity of the in-phase and the antiphase sources. We achieve accurate localization ability of the phased array system by accounting for the influence of asymmetrical boundaries and the heterogeneous background absorption. Experimental data on human breast phantoms demonstrate that localization accuracy within several millimeters has been accomplished through this method.

© 2002 Optical Society of America

Detection limit enhancement of fluorescent heterogeneities in turbid media by dual-interfering excitation

Xavier Intes, Yu Chen, Xingde Li, and Britton Chance
Appl. Opt. 41(19) 3999-4007 (2002)

Interfering diffusive photon-density waves with an absorbing-fluorescent inhomogeneity

X. Intes, B. Chance, M.J. Holboke, and A.G. Yodh
Opt. Express 8(3) 223-231 (2001)

Spatial localization of absorbing bodies by interfering diffusive photon-density waves

A. Knüttel, J. M. Schmitt, and J. R. Knutson
Appl. Opt. 32(4) 381-389 (1993)

Fluorescent diffuse photon density waves in homogeneous and heterogeneous turbid media: analytic solutions and applications

X. D. Li, M. A. O'Leary, D. A. Boas, B. Chance, and A. G. Yodh
Appl. Opt. 35(19) 3746-3758 (1996)

Signal-to-noise analysis for detection sensitivity of small absorbing heterogeneity in turbid media with single-source and dual-interfering-source

Yu Chen, Chenpeng Mu, Xavier Intes, and Britton Chance
Opt. Express 9(4) 212-224 (2001)