Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Disclosed is an apparatus for producing capsules of the type which are formed by immersing liquid droplets in a gelling agent. The apparatus comprises a rotor disposed about a central axis of rotation which houses a reservoir for holding the liquid to be formed into capsules, and conduits which lead to ports spaced uniformly on the circumference of a circle. When the rotor is actuated, spheroidal droplets of the capsule-forming material take shape at the ports and are propelled radially outwardly into a gelling agent contained in a reservoir which comprises an annular surface spaced radially apart from the ports.

Abstract: Chemical analysis of a sample with reagents spotted on a fibrous or porous medium employs a medium pretreated both with reagents and with conditioning agent. The conditioning agent increases the degree to which the liquid reactants wet the medium. One form of pretreated medium has different reagents located predominantly within different selected zones.Liquid is applied to the medium, typically as diluted sample, at a rate selected to enhance formation of repeatable spots. In one embodiment the liquid is applied by flowing it onto a wick element seated on the medium. The wick is disc-like and small relative to the spot which the reactants form on the medium. The disc can be pretreated to carry reagent, which the liquid transfers to the medium.The analysis instrument receives a reaction medium between selectively recessed upper and lower surfaces aligned in opposition at the reaction spot being analyzed.

Abstract: Chemical analysis of a sample with reagents spotted on a fibrous or porous medium employs a medium pretreated both with reagents and with conditioning agent. The conditioning agent increases the degree to which the liquid reactants wet the medium. One form of pretreated medium has different reagents located predominantly within different selected zones.Liquid is applied to the medium, typically as diluted sample, at a rate selected to enhance formation of repeatable spots. In one embodiment the liquid is applied by flowing it onto a wick element seated on the medium. The wick is disc-like and small relative to the spot which the reactants form on the medium. The disc can be pretreated to carry reagent, which the liquid transfers to the medium.The analysis instrument receives a reaction medium between selectively recessed upper and lower surfaces aligned in opposition at the reaction spot being analyzed.

Abstract: An optically-thin preparation of a sample solution and chemical reagents produces a constituent-manifesting reaction product that can be measured in linear relation to the concentration of the constituent of interest. A fibrous sheet contains the sample and the reagents for both the reaction and the measurement. The same site on the fibrous sheet which bears the reacting materials serves as a blank to produce a reference signal for the measurement.

Abstract: A press for compressing a liquid-bearing absorbent article to transfer a portion of the liquid materials to a contiguous article has two concentric pressure feet. One is an outer foot member that bears against the liquid-bearing article along the periphery of the pressure area, and the other is an inner, deformable and contoured foot member that applies pressure to the liquid-bearing article progressively along the pressure area. A photometer can be combined with the press to measure constituents or other properties of the liquid materials being transferred.