A blood measurement device for determining the amount of blood of a subject within a fluid sample, the fluid sample having a volume, the blood measurement device comprising: a light source configured to selectively generate light at a first wavelength and at a second wavelength different from the first wavelength; at least one photodetector, wherein the light source and the at least one photodetector are configured for positioning in an operative position, wherein, in the operative position, the at least one photodetector is configured to receive at least a portion of the light generated by the light source, and wherein upon positioning of the light source and the at least one photodetector in the operative position, the at least one photodetector is configured to produce a first signal indicative of the absorbance of the fluid sample at the first wavelength and a second signal indicative of the absorbance of the fluid sample at the second wavelength; and a processor operatively coupled to the at least one photodetector, wherein the processor is configured to receive the first and second signals from the at least one photodetector, and wherein, based upon the received first and second signals, the processor is configured to repeatedly determine the concentration of hemoglobin within the fluid sample, wherein the at least one photodetector comprises an array of a plurality of photodetectors, wherein each photodetector of the array of photodetectors is configured to produce a transmittance signal indicative of the transmittance of light measured by the photodetector, and wherein the processor is configured to receive the transmittance signal from each photodetector, wherein the light source comprises a plurality of light emitting diodes (LEDs), wherein at least one LED of the plurality of LEDs is configured to emit light at the first wavelength, and wherein at least one LED of the plurality of LEDs is configured to emit light at the second wavelength, and wherein the blood measurement device further comprises a plurality of pairs of opposed optical fibers, each pair of optical fibers comprising a first optical fiber operatively coupled to a corresponding LED of the plurality of LEDs and a second optical fiber operatively coupled to a corresponding photodetector of the plurality of photodetectors, wherein the plurality of pairs of opposed optical fibers are spaced apart relative to a vertical axis, wherein the processor is configured to determine a volume of blood within the fluid sample based upon a previously measured hemoglobin concentration of the subject, the determined hemoglobin concentration within the fluid sample, and the volume of the fluid sample, wherein the plurality of pairs of opposed optical fibers are configured for selective insertion within the fluid sample. a light source configured to selectively generate light at a first wavelength and at a second wavelength different from the first wavelength; at least one photodetector, wherein the light source and the at least one photodetector are configured for positioning in an operative position, wherein, in the operative position, the at least one photodetector is configured to receive at least a portion of the light generated by the light source, and wherein upon positioning of the light source and the at least one photodetector in the operative position, the at least one photodetector is configured to produce a first signal indicative of the absorbance of the fluid sample at the first wavelength and a second signal indicative of the absorbance of the fluid sample at the second wavelength; and a processor operatively coupled to the at least one photodetector, wherein the processor is configured to receive the first and second signals from the at least one photodetector, and wherein, based upon the received first and second signals, the processor is configured to repeatedly determine the concentration of hemoglobin within the fluid sample, wherein the at least one photodetector comprises an array of a plurality of photodetectors, wherein each photodetector of the array of photodetectors is configured to produce a transmittance signal indicative of the transmittance of light measured by the photodetector, and wherein the processor is configured to receive the transmittance signal from each photodetector, wherein the light source comprises a plurality of light emitting diodes (LEDs), wherein at least one LED of the plurality of LEDs is configured to emit light at the first wavelength, and wherein at least one LED of the plurality of LEDs is configured to emit light at the second wavelength, and wherein the blood measurement device further comprises a plurality of pairs of opposed optical fibers, each pair of optical fibers comprising a first optical fiber operatively coupled to a corresponding LED of the plurality of LEDs and a second optical fiber operatively coupled to a corresponding photodetector of the plurality of photodetectors, wherein the plurality of pairs of opposed optical fibers are spaced apart relative to a vertical axis, wherein the processor is configured to determine a volume of blood within the fluid sample based upon a previously measured hemoglobin concentration of the subject, the determined hemoglobin concentration within the fluid sample, and the volume of the fluid sample, wherein the plurality of pairs of opposed optical fibers are configured for selective insertion within the fluid sample.