Optix LP

Other

Chiron Diagnostics Corporation

Lester Sodickson

Myron J Block

Howard E Guthermann

Ronald S Scharlack

An improved method and apparatus for use in optical testing of concentration in samples has been developed. The apparatus restricts the solid angle of illumination and the solid angle of detection to eliminate a high proportion of the scattered radiation while allowing the ballistic radiation and the snake-like radiation to be transmitted. In samples which contain multiple scattering centers, this allows less correction for variations in effective pathlength and allows easier calibration of the apparatus. The use of polarized radiation as a means of minimizing scattered radiation in the sample is also disclosed.

Methods of minimizing scattering and improving tissue sampling in non-invasive testing and imaging

Methods of minimizing scattering and improving tissue sampling in

The present invention provides a generally applicable apparatus and method for achieving measurements of a constituent in a sample. This is achieved by employing a detection means having a plurality of detectors responsive to radiation in a selected region of the spectrum, e.g., the infrared. In most embodiments, at least two of the detectors provide broad wavelength bandpass. If narrow bandpass sources or detectors are used, the information generated is processed in a manner similar to broadband information. The broad bandpass response of the detectors can be contrasted with the approach of classical spectrophotometry, in which the spectral response of the detectors is designed to be as narrow as feasible, and substantially narrower than the spectral features of the constituent or constituents of interest. The data is processed such that the contributions of known background constituents and scattering is eliminated prior to further processing, thereby yielding a better result in high background situations. The use of intensity processing rather than absorbance processing also allows the method and apparatus to be used in a variety of non-ideal situations.

Rapid non-invasive optical analysis using broad bandpass spectral

Improvement methods and apparatus for determination of optical properties of objects have been developed. The apparatus and methods of the invention provide an analog of color perception of human vision, preferably in the near infrared region, replacing spectrophotometers and narrow band sources used in other non-invasive near infrared detection methods. A plurality of detector units are used, each covering a broad and overlapping region of the detected spectrum, paralleling color perception and colorimetry. The improvements are primarily concerned with improving the signal-to-background (or noise) ratio such that the data stream is improved. These improvements use congruent sampling, comparison of different data streams from different sample portions or filter sets, using an interrogation system with sufficient speed to allow testing of arterial blood, and using a filter with a spectral structure. In some circumstances, a neural net is used for analysis, allowing the system to learn. A novel method for background discrimination is also described.

Non-spectrophotometric measurement of analyte concentrations and optical

The present invention provides apparatus and methods for determining the concentration of sample components of a sample by an analytical technique that yields a spectrum that can be written as Y(.omega.)=P(.omega.).multidot.C. The apparatus and methods of the invention account for experimental errors that give rise to distortions in the observed spectrum and that consequently result in inaccurate determinations of sample component concentrations. The invention accounts for such errors by modeling the total experimental error as the sum of one or more types of errors that can be written as .xi..multidot.K. The spectrum is then modeled as Y=P.multidot.C+.xi..multidot.K. Using the observed spectrum, known values for P, and a mathematical model for .xi., this equation can be solved for the best fit value of the sample component concentrations, C, and the magnitudes of the errors, K. The method can be used for any error that can be modeled in the foregoing manner, such as a shift in the spectrum. Particular types of shift include constant shift as well as linear shift across the entire spectrum. The apparatus and methods are advantageously used in absorbance spectroscopy and chromatography.

Apparatus and methods for the analytical determination of sample

Improvements in non-invasive detection methods for glucose and other constituents of interest in a sample have been developed. The apparatus and methods of the invention provide an analog of color perception of human vision, preferably in the near infrared region, replacing spectrophotometers and narrow band sources used in other non-invasive near infrared detection methods. A plurality of detector units are used, each covering a broad and overlapping region of the detected spectrum, paralleling color perception and colorimetry. The improvements are primarily concerned with improving the signal-to-background (or noise) ratio such that the data stream is improved. These improvements use congruent sampling, comparison of different data streams from different sample portions or filter sets, using an interrogation system with sufficient speed to allow testing of arterial blood, and using a filter with a spectral structure. In some circumstances, a neural net is used for analysis, allowing the system to learn. A novel method for background discrimination is also described.

A new non-invasive non-spectrophotometric method for measuring the blood concentration of analytes such as glucose has been developed. The apparatus and methods of the invention exploit analogies with colorimetry and color perception to extract concentration measurements from the global structure of the intensity versus wavelength absorbance or transmission profile. A plurality of broad spectrum filters transmit distinguishably coded beams of radiation in overlapping portions of the spectrum to the sample. Radiation reflected or transmitted by the sample is detected and decoded. LED's may be used instead of the broad spectrum radiation generating device and the filters. Further, a scanning interferometer can be used as the illuminating and coding device. In a preferred mode, congruent illumination is utilized. The coded signals are analyzed by analogy to colorimetry and visual processing and can be converted into concentration measurements.

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Waban, MA, United States of America

Lester Sodickson