Patent ID: 7412340
Filing Date: 2008-08-12
Classification: G01N,H01Q

Abstract:
1. A method for detecting a selected material in a sample, comprising holding the sample while shielding the sample from ambient electrical and magnetic energy; introducing noise into the sample to induce stochastic resonance; storing, for each of one or more preselected materials including the selected material, a data set containing low-frequency spectral components that are of a selected frequency range approximately above DC; wherein the data set contains low-frequency spectral components that are of a selected frequency approximately below 50 kHz, and characteristic of the selected material; producing, adjacent to the sample, a time-domain signal having signal components related to low-frequency electromagnetic radiation produced by the selected material in the sample; converting the produced signal to an amplified signal from which frequency components above a selected frequency are substantially omitted; retrieving a data set of low-frequency spectral components characteristic of the selected material; filtering the produced signal to selectively pass low-frequency spectral components corresponding to low-frequency spectral components of the retrieved data set; cross-correlating the produced signal with the retrieved data set of low-frequency spectral components to produce a frequency-domain signal, wherein the frequency-domain signal has a frequency approximately above DC; wherein the frequency-domain signal has a frequency approximately below 50 kHz; determining whether the frequency-domain signal contains one or more low-frequency signal components that are characteristic of the selected material, and diagnostic of a presence or absence of the selected material in the sample; and displaying an output associated with whether the frequency-domain signal contains one or more low-frequency signal components that are characteristic of the selected material.