Light source wavelength correction
AssigneeSiemens Medical Solutions Diagnostics
InventorWillis E. Howard, III
Life of this patent
Estimating the term…
Abstract
A wavelength correction function provides corrected reflectance values from actual reflectance values taken in a reflectance-base instrument. The correction is provided as a function of measured reflectance values and a predefined set of high resolution reflectance values established for the reflectance-based instrument implementing the wavelength correction function.
Claims27
A method of correcting one or more reflectance values when a center wavelength of one or more light sources used to generate corresponding light signals is different from a specified center wavelength for the one or more light sources, the method comprising the steps of:
- A. defining, for each of the one or more light sources, a reference spectral distribution {L*} that is characteristic of the one or more light sources and composed of reference light intensity values over a set of reference wavelengths;
- B. defining, for each of the one or more light sources, a spectral distribution {L} comprising actual light intensity values over the set of wavelengths;
- C. determining the actual reflectance R of a set of reflected signals;
- D. defining a set of detector sensitivity data {D} corresponding to the set of detectors receiving the set of reflected signals;
- E. determining high resolution reflectance values {r};
- F. determining a correction factor as a function of {L}, {L*}, {r} and {D};
- and
- G. applying the correction factor to R to determine R*.
A center wavelength correction system configured to correct one or more reflectance values when a center wavelength of one or more light sources used to generate corresponding light signals is different from a specified center wavelength for the one or more light sources, the system comprising:
- A. a spectral distribution module configured to determine, for each of the one or more light sources, a spectral distribution {L} comprising actual light intensity values over the set of wavelengths;
- B. a reflectance module configure to determine actual reflectance R from a set of reflected signals;
- C. at least one storage device comprising:
- 1) for each of the one or more light sources, a reference spectral distribution {L* } that is characteristic of the one or more light sources and composed of reference light intensity values over a set of reference wavelengths;
- 2) high resolution reflectance values {r};
- and
- 3) detector sensitivity data {D} corresponding to the set of detectors receiving the set of reflected signals;
- D. a correction function module configured to determine a correction factor at a given wavelength as a function of {L}, {L*}, {r} and {D} and to apply the correction factor to R to determine R*.
A wavelength correction means for correcting one or more reflectance values when a center wavelength of one or more light sources used to generate corresponding light signals is different from a specified center wavelength for the one or more light sources, the system comprising:
- A. a spectral distribution means for determining, for each of the one or more light sources, a spectral distribution {L} comprising actual light intensity values over the set of wavelengths;
- B. a reflectance means for determining actual reflectance R from a set of reflected signals;
- C. at least one storage means far storing:
- 1) for each of the one or more light sources, a reference spectral distribution {L} that is characteristic of the one or more light sources and composed of reference light intensity values over a set of reference wavelengths;
- 2) high resolution reflectance values {r};
- and
- 3) detector sensitivity data {D} corresponding to the set of detectors receiving the set of reflected signals;
- D. a correction function means for determining a correction factor at a given wavelength as a function of {L}, {L*}, {r} and {D} and to apply the correction factor to R to determine R*.
A reflectometer comprising:
- A. a set of light sources;
- B. a set of detectors;
- C. a reflectance assembly configured to direct light signals from the set of light sources onto a test product and to direct light signals reflected from the test product onto the set of detectors;
- D. at least one storage device configured to store a reference spectral distribution {L*}, a set of high resolution reflectance values {r}, a set of detector sensitivity data {D} corresponding to the set of detectors, a measured spectral distribution {L} corresponding tote set of light sources, and a set of measured reflectance values R;
- and
- E. a correction function module for determining a correction factor at a given wavelength as a function of {L}, {L*}, {r} and {D} and to apply the correction factor to R to determine R*.
A wavelength correction module, in a reflectance-based system comprising a set of light sources, a set of detectors, and a reflectance assembly configured to direct light signals from the set of light sources onto a test product and to direct light signals reflected from the test product onto the set of detectors, the wavelength correction module comprising:
- A. at least one storage device configured to store a reference spectral distribution {L*}, a set of high resolution reflectance values {r}, a set of detector sensitivity data {D} corresponding to the set of detectors, a measured spectral distribution {L} corresponding to the set of light sources, and a set of measured reflectance values R;
- and
- B. a correction function module for determining a correction factor at a given wavelengths a function of {L}, {L*}, {r} and {D} and to apply the correction factor to R to determine R*.
Dependencies are inferred from the claim text.