A method is provided for building improved calibration models or for improving modifications to these models or validation of the models used in the non-invasive spectroscopic measurement of an analyte or attribute of tissue. The method uses a matched reference sample and measurement of that sample to ensure that the correct relationship between the spectra and analyte is made during the model building, modification or calibration process. A matched reference sample is one in which the analyte of interest or attribute of interest in the reference sample is representative of the analyte or attribute at the site being non-invasively sampled or the agreement between the reference concentration and the non-invasively sampled concentration is clinically significant.

Apparatus and method for non-invasive spectroscopic measurement of analytes in tissue using a matched reference analyte

Methods and systems are provided for identifying an individual. Electromagnetic radiation is propagated into tissue of the individual. A measured spectral variation is received in the form of electromagnetic radiation scattered from the tissue of the individual. The measured spectral variation is compared with a previously stored spectral variation over a predetermined wavelength interval. The comparison is performed at each of multiple wavelengths within the predetermined wavelength interval and is performed of a property of the measured and previously stored spectral variations that is independent of a presence of other wavelengths. The individual is designated as having an identity associated with the previously stored spectral variation if the measured spectral variation is consistent with the previously stored spectral variation.

Methods and systems for biometric identification of individuals using linear optical spectroscopy

Methods and systems for performing a biometric measurement on an individual are disclosed. A containment film is disposed between a skin site of the individual and a platen. Light is directed through the containment film to the skin site to illuminate the skin site under multiple distinct optical conditions. Light scattered from the skin site is received for the multiple optical conditions. A multispectral image of the skin site is derived from the received light. A biometric function is performed with the derived multispectral image.

Hygienic biometric sensors

Spectroscopic system and spectrometers including an optical bandpass filter unit consisting of a plurality of bandpass regions and a spatial encoding unit for encoding discrete frequencies of light passing through the optical filter. The incorporation of the encoding unit allows the spectrometer system to use a detector consisting of one or a small number of elements, rather than using a more expensive detector array as is commonly used with filter-based spectrometers. The system can also include an integrating chamber that collects the light that is not transmitted through the bandpass filter unit and is substantially reflected, and redirects this light to strike the filter unit again, resulting in a significant increase in the optical power passing through the filter. The integrating chamber maximizes the return of the reflected light to the filter assembly and minimizes optical losses. The integrating chamber may be an orthogonal design to preserve the optical geometric characteristics of the light entering the chamber, even after multiple reflections from the optical filter.

Encoded variable filter spectrometer

Methods and systems are provided that extend the functionality of electro-optical sensors. A device has a multiple light sources, a light detector, and a processor configured to operate the light sources and the light detector to perform distinct functions. At least one of the distinct functions includes a biometric identification function in which light is propagated from the plurality of light sources through presented material. The propagated light is received with the light detector, with the presented material being identified from the received light. Another of the distinct functions includes a nonidentification function performed with the light sources and the light detector.

Electro-optical sensor

A color projection display in which at least one color channel includes: a light source assembly including a multiplicity of pulse modulated light sources providing an aggregate light beam; a light modulation control subsystem; illumination optics to direct the aggregate light beam to an image modulation plane; and a spatial light modulator in the image modulation plane. The light modulation control subsystem senses an aggregate light intensity signal for the aggregate light beam and controls the pulse modulation parameters for the multiplicity of pulse-modulated light sources responsive to the sensed aggregate light intensity signal to reduce light intensity fluctuations in the aggregate light beam within the imaging time interval.

Light source modulation for projection

A film scanner illuminant system with a light integrator module for creating an homogenous light illuminant from a light source. Temporal variations in light beam profiles from the light source which introduce low level temporal variations in the spatial homogeneity of light from the integrator are reduced below level of perceptibility by use of a light shaping diffuser to diffuse the beam of input light at the light input port of the light integrator. Preferably asymmetric light diffusers are used although some additional advantage is obtainable by use of spherical diffusers. The diffuser may be used with a variety of known light integrator configurations.

Andrew F. Kurtz

Papers

Light source modulation for projection

Light integrating system with reduced dynamic shading

Light source control for projector with multiple pulse-width modulated light sources