Blood culture sensor station utilizing two distinct light sources

摘要

A method for determining whether a particular sample vial has bacterial growth includes the steps of introducing a first light into the sample vial and measuring the intensity of the reemerging light. One then introduces a second light which is different from the first light and has either a different wavelength, or is introduced at a different location than the first light. The reemerging intensity from the second light is also measured. A ratio quantity is calculated based on the two reemerging intensities, and the calculated ratio is compared to expected ratios for both positive and negative samples. It has been found that a comparison of the reemerging light intensities provides a very good indication of whether a particular sample is a positive or negative sample. Various methods and formulas for calculating the ratios may be utilized. Graphs associated with the particular methods and formulas are developed experimentally to allow one to compare a particular calculated ratio value to expected values for positive and negative cultures.