413 results about "Fluorescence spectroscopy" patented technology

Fluorescence spectral data acquired from tissues in vivo or in vitro is processed in accordance with a multivariate statistical method to achieve the ability to probabilistically classify tissue in a diagnostically useful manner, such as by histopathological classification. The apparatus includes a controllable illumination device for emitting electromagnetic radiation selected to cause tissue to produce a fluorescence intensity spectrum. Also included are an optical system for applying the plurality of radiation wavelengths to a tissue sample, and a fluorescence intensity spectrum detecting device for detecting an intensity of fluorescence spectra emitted by the sample as a result of illumination by the controllable illumination device. The system also include a data processor, connected to the detecting device, for analyzing detected fluorescence spectra to calculate a probability that the sample belongs in a particular classification. The data processor analyzes the detected fluorescence spectra using a multivariate statistical method. The five primary steps involved in the multivariate statistical method are (i) preprocessing of spectral data from each patient to account for inter-patient variation, (ii) partitioning of the preprocessed spectral data from all patients into calibration and prediction sets, (iii) dimension reduction of the preprocessed spectra in the calibration set using principal component analysis, (iv) selection of the diagnostically most useful principal components using a two-sided unpaired student's t-test and (v) development of an optimal classification scheme based on logistic discrimination using the diagnostically useful principal component scores of the calibration set as inputs.

The invention provides a system and method utilizing, among other things, fluorescence spectroscopy in the ultraviolet portion of the electromagnetic spectrum to determine chemical species and concentrations. The basic measuring system includes optics, a spectrograph, a detector, and an energy source (“head” components), along with a computer and control electronics and power source capable of generating and detecting unique fluorescence signatures for individual and unique mixtures of chemical substances including, for example, prescribed and / or compounded medications, alcohol products, food types, synthetic drugs, narcotics, perfumes, liquids, and the like.

The present invention relates to a functionally integrated microanalytical system for performing fluorescence spectroscopy. A source of fluorescence-exciting radiation, typically a LED, is integrated onto a substrate along with a photodetector and, in some embodiments, an optical filter. A pixel-to-point laser lift-off process is used to effect this component integration. For those cases in which a filter is required, a thin film bandgap filter is typically used, such as CdS or CdSxSe1-x (0<x<1). A disposable microchannel containing the sample and its fluorescent tag is mounted onto the integrated assembly of LED, photodetector and (optionally) filter. This configuration of components allows the microchannel and sample to be readily removed and replaced, facilitating rapid analysis of multiple samples. Multiple LEDS, detectors and filters (if present) can also be integrated onto the same substrate, permitting multiple wavelength analysis of the sample to be performed concurrently.

The present invention relates, e.g., to a method for determining the size distribution of DNA molecules in a sample comprising cell-free nucleic acid, comprising labeling the DNA with a fluorescent dye in a stoichiometric manner, subjecting the DNA to molecular spectroscopy (e.g., cylindrical illumination confocal spectroscopy), analyzing suitable fluorescent burst parameters of the labeled DNA, and conducting single molecule DNA integrity analysis of the labeled DNA molecules in the sample. In one embodiment of the invention, the method is used as a diagnostic method for detecting cancer.

Methods and apparatus for classifying tissue use features of Raman spectra and background fluorescent spectra. The spectra may be acquired in the near-infrared wavelengths. Principal component analysis and linear discriminant analysis of reference spectra may be used to obtain a classification function that accepts features of the Raman and background fluorescence spectra for test tissue and yields an indication as to the likelihood that the test tissue is abnormal. The methods and apparatus may be applied to screening for skin cancers or other diseases.