Illumination device and method for spectroscopic analysis
First Claim
1. An illumination subsystem for use in optical analysis of a sample comprising:
- a light source generating radiation and means for spatially and angularly homogenizing at least a portion of said radiation, said means for spatially and angularly homogenizing at least a portion of said radiation disposed between said light source and said sample.
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Accused Products
Abstract
An illumination subsystem for use in optical analysis which provides spatially and angularly homogenized radiation to the sample being analyzed. The system eliminates the illumination system as an interferent in the overall optical analysis. Thus, modest translations or rotations of the illumination source or changing the illumination source does not require recalibration of the instrument or prior modeling of illumination variability due to such changes. Illumination stability is achieved by incorporating a light pipe which both angularly and spatially homogenizes the light. Further, a series of filters and/or lenses are incorporated to provide bandpass filtering which eliminates unwanted wavelengths or bands of wavelengths from contacting the tissue and allows for a higher signal-to-noise ratio when the sample is tissue, while preventing thermal damage.
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Citations
53 Claims
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1. An illumination subsystem for use in optical analysis of a sample comprising:
a light source generating radiation and means for spatially and angularly homogenizing at least a portion of said radiation, said means for spatially and angularly homogenizing at least a portion of said radiation disposed between said light source and said sample. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An illumination subsystem for use in optical analysis of a sample comprising:
a light source generating radiation and a radiation homogenizer disposed between said light source and said sample for spatially and angularly homogenizing at least a portion of said radiation prior to illuminating said sample. - View Dependent Claims (8, 9, 10, 11, 12, 16, 17, 18, 19)
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13. An illumination subsystem for use in optical analysis of a sample comprising:
a light source including a filament generating radiation, wherein the radiation exiting the illumination subsystem has a spatial and angular distribution which is repeatable through a one-millimeter vertical translation of the filament resulting in a standard deviation of less than 0.053 in spatial distribution and a standard deviation of less than 0.044 in angular distribution.
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14. An illumination subsystem for use in optical analysis of a sample comprising:
a light source including a filament generating radiation, wherein the radiation exiting the illumination system has a spatial and angular distribution which is repeatable through a 90-degree rotational translation of the filament resulting in a standard deviation of less than 0.050 in spatial distribution and a standard deviation of less than 0.066 in angular distribution.
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15. An illumination subsystem for use in optical analysis of a sample comprising:
an illumination system with a light source that reduces the inverse multivariate signal-to-noise value to 60 or less when the light source is changed in the illumination subsystem.
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20. A light pipe for use in conjunction with spectroscopic analysis, the light pipe comprising:
a proximal end, a distal end, and a length of material therebetween, the light pipe further having a non-circular polygonal cross-sectional area, wherein the light pipe internally reflects radiation introduced through the proximal end of the light pipe, and wherein the radiation emitted from the distal end of the light pipe has been spatially and angularly homogenized by the light pipe. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. A spectroscopic system for measuring analyte concentration in a sample, the system comprising:
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a radiation source emitter, the emitter emitting radiation;
a radiation homogenizer disposed to receive at least a portion of said emitted radiation, wherein the homogenizer angularly and spatially homogenizes at least a portion of said emitted radiation, wherein said homogenized radiation illuminates said sample; and
a sample source, the sample source having an analyte; and
a detector for receiving at least a portion of the radiation subsequent to interacting with said sample. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 49)
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48. A method for homogenizing radiation for spectroscopic analysis, the method comprising the steps of:
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providing a spectroscopic system, wherein the system comprises a radiation source emitter, a radiation homogenizer, a sample having an analyte concentration, and a radiation detector;
emitting radiation by means of the radiation source emitter;
angularly homogenizing the emitted radiation;
spatially homogenizing the emitted radiation;
illuminating the sample source with the homogenized radiation; and
detecting the analyte concentration within the sample source.
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50. An optical measurement system used to measure an analyte or attribute in a biological system, the system comprising:
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a spectrometer including a source and a collection system;
a sampling system for performing reflectance measurements on tissue;
a measurement system for measuring multiple wavelengths in the range for 4000 cm−
1 to 7500 cm−
1;
a prediction process that uses multiple variables obtained from the measurement system; and
an illumination system that does not introduce prediction errors of clinical significance when used in a standard manner. - View Dependent Claims (51, 52, 53)
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Specification