Microbial detection apparatus and method

A microbial detection apparatus comprising:

• a fluid flow tube configured to carry a flow of fluid;
• a light source configured to direct a beam of light toward the flow tube;
• a parabolic reflector for reflecting fluorescence light, emitted from microbes within the fluid upon interaction with light from the light source;
• a first detector for detecting fluorescence light emitted from microbes within the fluid passing through the flow tube;
• a second detector for detecting Mie scattered light from particles within the fluid passing through the flow tube;
• an interference filter positioned along the axis of symmetry of the parabolic reflector to block excitation light wavelength;
• a first lens for focusing the fluorescence light onto the first detector, wherein said first detector comprises a photomultiplier tube;
• and
• a second lens for focusing the Mie scattering light onto the second detector, wherein said second detector comprises a photodiode, wherein
• a beam blocker is positioned near the center of the second lens for blocking an unscattered portion of the light emitted from the light source,
• the light beam path and the flow tube intersect at the focal point of the parabolic reflector,
• the parabolic reflector includes holes to allow the entrance of light from the light source, and to allow the flow tube to pass through the parabolic reflector, and
• the light source is positioned such that light is emitted along a path that is at an oblique angle with respect to the axis of symmetry of the parabolic reflector.

A microbial detection apparatus comprising:

• a fluid flow tube configured to carry a flow of fluid;
• a light source configured to direct a beam of light toward a mirror, said mirror configured to direct the light toward the flow tube;
• a parabolic reflector for reflecting fluorescence light, emitted from microbes within the fluid upon interaction with light from the light source;
• a first detector for detecting fluorescence light emitted from microbes within the fluid passing through the flow tube;
• a second detector for detecting Mie scattered light from particles within the fluid passing through the flow tube;
• an interference filter positioned along the axis of symmetry of the parabolic reflector to block excitation light wavelength;
• a first lens for focusing the fluorescence light onto the first detector, wherein said first detector comprises a photomultiplier tube;
• and
• a second lens for focusing the Mie scattering light onto the second detector, wherein said second detector comprises a photodiode, wherein
• a beam blocker is positioned near the center of the second lens for blocking an unscattered portion of the light emitted from the light source,
• the light beam reflected by the mirror and the flow tube intersect at the focal point of the parabolic reflector,
• the mirror is positioned near the center of the interference filter,
• the parabolic reflector includes holes to allow the exit of light from the light source, and to allow the flow tube to pass through the parabolic reflector, and
• the light reflected by the mirror travels inwardly toward and through the focal point of the parabolic reflector.

A method of microbial detection, comprising:

• providing a flow of fluid through a flow tube, said flow tube passing through a focal point of a parabolic reflector;
• directing a beam of light toward the flow tube, said beam of light intersecting with the flow tube at the focal point of the parabolic reflector;
• reflecting, by the parabolic reflector, fluorescence light emitted from microbes within the fluid upon interaction with the light beam;
• detecting with a first detector the emitted fluorescence light;
• and
• detecting with a second detector Mie scattered light resulting from interaction of the light beam with particles within the fluid.