Abstract: A method and system for calibrating an optical tomographic imaging system that is configured to execute time-series optical measurements of a target's response to incident optical energy is presented. An electro-active device that is configured to be electronically modulated to control the electro-active device's opacity is embedded in a dense scattering medium. A known hemodynamic response pattern is selected and at least one wavelength of optical energy that produces the known hemodynamic response pattern is determined. A wavelength-dependent driving voltage function is then computed. A voltage is then applied to the electro-active device according to the wavelength-dependent driving voltage function. Optical energy is then transmitted to the scattering medium at the at least one wavelength and a hemodynamic response for the target is determined. The known hemodynamic response pattern and the determined hemodynamic response pattern are then compared.

Abstract: A method of measuring local and propagating pulsatile behavior of a vasculature system provides a way to non-invasively measure vascular dynamics and, in particular, allows for objective measurement of the propagating expansion-contraction waves. The method includes capturing a time-series of optical images, and analyzing the images to produce a time-series of vector field maps based on measurements of local displacement of hemoglobin contrast. The method further includes obtaining a resulting time-dependent tensor field image and analyzing the resulting time-dependent tensor field image to obtain metrics of local and propagating oscillatory behavior.

Abstract: A method for imaging functional states of tissue associated with provocation dependent tissue-vascular responses is described. In its preferred embodiment the method combines dynamic near infrared optical tomographic imaging with feature extraction methods to produce a composite image whose particulars can serve to differentiate healthy tissue from diseased, monitor tissue response to therapy or measure tissue responses to pharmaceutical agents. When combined with simultaneous multisite optical measurements, the described method can be used to differentiate local and system-wide responses.

Abstract: Data from a target system (616) that exhibits a non-linear relationship between system properties and measurement data, is processed by applying a linear filter (F) to improve resolution and accuracy. The filter reduces inaccuracies that are introduced by an algorithm used to reconstruct the data. The filter is defined by assigning time varying functions, such as sinusoids (200), to elements (210) in a model (Y) of the system to perturbate the elements. The resulting data output from the model is reconstructed using the same algorithm used to subsequently reconstruct the data from the target system. The filter is defined as a matrix (F) that transforms the reconstructed data of the model (X) back toward the known properties of the model (Y). A library of filters can be pre-calculated for different applications. In an example implementation, the system is tissue that is imaged using optical tomography.

Abstract: A method of significantly improving the quality of solutions to a system of linear equations. The solution to a system of linear equations is enhanced by: (1) modeling a target medium into a plurality of elements and imposing at least one localized fluctuation into the target medium; (2) measuring an output resulting from at least one localized fluctuation; and (3) processing the measured output to reconstruct a result, determining a correction filter, and applying the correction filter to the result.