Timeshared Differential Pathlenght Spectrophotometer

This contract will design a time-shared three wavelength phase modulation spectrophotometerto provide differential path length information directly, thereby eliminating the need for optical benchcalibration. The instrument will employ a synchronous electronic switching circuit to illuminatesequentially three laser diodes at wavelengths of 754, 785, and 816 nm driven at a frequency of 200megahertz. The contractor shall correlate the response of the instrument over the entire range of oxygensaturation in a model system. In addition, the contractor shall also compare the combination 754, 785,and 816 nm versus 754, 816, 840 nm, and characterize instrument response to incremental oxygenationcovering the range of 0 to 100% saturation at varying hematocrits in the physiologic range.