Analyte system and method for determining hemoglobin parameters in whole blood
An optical spectrometer for use in a COOx analyzer includes a spectrometer housing having an optical fiber housing end, a light-receiving input slit positioned adjacent the optical fiber housing end, a light dispersing element mounted to but spaced from the optical fiber housing end and positioned within an optical path along which light travels from the light-receiving input slit. The light dispersing element receives the light transmitted through the input slit and separates the light into a plurality of light beams, a light-array detector capable of receiving the plurality of light beams and converting the plurality of light beams into the electrical signal, an achromatic lens positioned in the optical path to direct the light from the input slit to the light dispersing element and to direct the plurality of light beams reflected from the light dispersing element onto the light-array detector, and a thermal-compensating means for the spectrometer housing.
1. An optical spectrometer for use in a COOx analyzer, the spectrometer comprising:
a spectrometer housing having a baseplate and an optical fiber housing end;
a light-receiving input slit positioned adjacent the optical fiber housing end of the spectrometer housing;
a light dispersing element mounted to the baseplate spaced from the optical fiber housing end of the spectrometer housing and positioned within an optical path along which light travels from the light-receiving input slit, the light dispersing element being capable of receiving the light transmitted through the input slit, separating the light into a plurality of light beams wherein each light beam has a different wavelength, and re-directing the plurality of light beams;
a light-array detector next to the light-receiving input slit, the light-array detector capable of receiving the plurality of light beams and converting the plurality of light beams into the electrical signal;
an achromatic lens assembly located between the light dispersing element and the light-receiving input slit, the achromatic lens assembly having an achromatic lens positioned in the optical path to direct the light from the input slit to the light dispersing clement and to receive the plurality of light beams reflected from the light dispersing element and directing the plurality of light beams onto the light-array detector; and
thermal-compensating means for maintaining a position of the plurality of light beams on the light-array detector, the thermal-compensating means comprising one or more of insulation disposed around the spectrometer housing, a temperature controller assembly attached to the spectrometer housing, and a thermal-compensating lens mount supporting the achromatic lens, the thermal-compensating lens mount being disposed within the spectrometer housing.
2. The optical spectrometer of claim 1 wherein the thermal-compensating lens mount has a fixed mount end and an unfixed mount end wherein the unfixed mount end permits thermal expansion and contraction of the thermal-compensating lens mount, the fixed mount end being fixedly attached to one of the baseplate or a bottom of the spectrometer housing and wherein the lens mount has a coefficient of expansion greater than the coefficient of expansion of the baseplate or the bottom of the spectrometer housing to which the compensating lens mount is attached.
3. The optical spectrometer of claim 1 wherein the thermal-compensating lens mount moves linearly and transversely relative to an optical path of the light from the light input slit based on the coefficient of expansion of the lens mount to maintain the position of the dispersed light from the light dispersing element on the light-array detector.
4. The optical spectrometer of claim 1 wherein the thermal-compensating lens mount moves linearly and transversely relative to the optical path due to a temperature change within the spectrometer housing to effect the re-positioning of the achromatic lens causing the plurality of light beams to impinge onto the light-array detector without affecting the electrical signal.
5. The optical spectrometer of claim 2 wherein the unfixed mount end has a hold-down fastener disposed through a slot of the lens mount wherein the slot permits expansion and contraction of the lens mount due to a temperature change within the spectrometer housing.
6. The optical spectrometer of claim 1 wherein the achromatic lens is located in an off-axis position relative to the optical path along which light travels from the light-receiving input slit.
7. The optical spectrometer of claim 1 wherein the light dispersing element is a Littrow prism.
8. The optical spectrometer of claim 7 wherein the Littrow prism has a reflective coating on a side opposite a ninety degree angle of the Littrow prism.
9. The optical spectrometer of claim 1 wherein the light-receiving input slit and the light-array detector are mounted on the same side of a single substrate adjacent each other.