United States Patent  [ii] Patent Number: 5,164,597
Lodder  Date of Patent: Nov. 17,1992
4,804,273 2/1989 Tondello et al 250/574
4,900,923 2/1990 Gerlinger 250/228
Primary Examiner—Carolyn E. Fields
Attorney, Agent, or Firm—King & Schickli
An apparatus and method are provided for the noninvasive and nondestructive detection of microorganisms within a liquid product contained within a sealed vial. The apparatus includes a near-IR light source that produces both incident and reference beams having a wavelength between 800 and 2500 nm and, more preferably, 1100 and 1360 nm. The apparatus also includes an integrating sphere having incident and reference beam ports and a sample window opposite the incident beam port. A detector is mounted in the integrating sphere substantially adjacent the sample window. A substantially U-shaped mirror is provided to hold the vial. The U-shaped mirror is of a size substantially corresponding to the diameter of the vial. In operation, the incident beam is directed through a sample window so as to enter the vial adjacent a sidewall of the mirror. In this way the U-shaped mirror reflects the incident beam so that it passes through the vial three times before returning to the detector. A computer analyzes the resulting signals from the detector.
19 Claims, 19 Drawing Sheets