Apparatus, system and method for measuring properties of a sample

A device comprising an optical apparatus for monitoring bacterial growth of a drug-dosed liquid biological sample, the device comprising:

• a sample container port for receiving a sample container, in use, the sample container having at least one detection chamber for containing the drug-dosed sample;
• and the optical apparatus comprising:
• a light source configured to emit light along an incident beam axis that, in use, intersects with at least one detection chamber of the sample container, and to illuminate the drug-dosed sample contained within the detection chamber;
• a first photodetector configured to receive light scattered by bacteria in the sample;
• a light collection arrangement configured to:
• collect light exiting the detection chamber that has been scattered in a forward direction by bacteria in the sample, in a range of scattering angles between about +/−4 and +/−20 degrees relative to the incident beam axis, and to direct the collected scattered light to the first photodetector;
• and
• prevent non-scattered light travelling parallel to the incident beam axis and exiting the detection chamber from reaching the first photodetector;
• and
• at least one processor configured to:
• (a) measure an intensity of the scattered light received by the first photodetector;
• (b) determine a corresponding representative amount or concentration of bacteria present in the sample based on the intensity of the scattered light;
• (c) repeat the measuring step (a) and the determining step (b) at a series of pre-determined intervals to determine changes in the representative amount or concentration of bacteria present in the sample as a function of time;
• and
• (d) determine a corresponding susceptibility of the bacteria in the sample to the respective drug,
• wherein the light collection arrangement comprises first and second condensing lenses and a mirror, wherein:
• the first condensing lens is configured to direct the scattered light to the second condensing lens, and to focus non-scattered light travelling along the incident beam axis onto the mirror;
• and
• the second condensing lens is configured to receive the scattered light from the first condensing lens and to focus the scattered light onto the first photodetector;
• and
• wherein the mirror is arranged along the incident beam axis between the first and second condensing lenses and is configured to reflect the non-scattered light away from the first photodetector.

A system for monitoring bacterial growth of a drug-dosed liquid biological sample, the system comprising:

• a device comprising:
• a sample container port for receiving a sample container, in use, the sample container having at least one detection chamber for containing the drug-dosed sample;
• and
• an optical apparatus comprising:
• a light source configured to emit light along an incident beam axis that, in use, intersects with at least one detection chamber of the sample container, and to illuminate the drug-dosed sample contained within the detection chamber;
• a first photodetector configured to receive light scattered by bacteria in the sample;
• a light collection arrangement configured to:
• collect light exiting the detection chamber that has been scattered in a forward direction by bacteria in the sample, in a range of scattering angles between about +/−4 and +/−20 degrees relative to the incident beam axis, and to direct the collected scattered light to the first photodetector;
• and
• prevent non-scattered light travelling parallel to the incident beam axis and exiting the detection chamber from reaching the first photodetector;
• and
• at least one processor configured to:
• (a) measure an intensity of the scattered light received by the first photodetector;
• (b) determine a corresponding representative amount or concentration of bacteria present in the sample based on the intensity of the scattered light;
• (c) repeat the measuring step (a) and determining step (b) at a series of pre-determined intervals to determine changes in the representative amount or concentration of bacteria present in the sample as a function of time;
• and
• (d) determine a corresponding susceptibility of the bacteria in the sample to the respective drug;
• wherein the light collection arrangement comprises first and second condensing lenses and a mirror, wherein:
• the first condensing lens is configured to direct the scattered light to the second condensing lens, and to focus non-scattered light travelling along the incident beam axis onto the mirror;
• and
• the second condensing lens is configured to receive the scattered light from the first condensing lens and to focus the scattered light onto the first photodetector;
• and
• wherein the mirror is arranged along the incident beam axis between the first and second condensing lenses and is configured to reflect the non-scattered light away from the first photodetector;
• and
• a sample container comprising a plurality of detection chambers, each detection chamber configured to contain a drug-dosed liquid biological sample;
• wherein the system further comprises:
• a sample positioning mechanism configured to align each of the plurality of detection chambers in turn with the incident beam axis such that the light source illuminates the drug-dosed liquid biological sample contained within the illuminated detection chamber.

A method for determining susceptibility of bacteria in a sample to a drug, the method comprising:

• (a) containing a drug-dosed liquid biological sample in a detection chamber of a sample container;
• (b) illuminating, by a light source, the sample in the detection chamber with light emitted along an incident beam axis that passes through the detection chamber;
• (c) collecting, by a light collector, light scattered by interaction with bacteria in the sample, the light being scattered in a forward direction in a range of scattering angles between +/−4 and +/−20 degrees relative to the incident beam axis;
• (d) concentrating, by the light collector, the collected scattered light onto a first photodetector, wherein the light collector comprises first and second condensing lenses and a mirror, wherein:
• the first condensing lens is configured to direct the scattered light to the second condensing lens, and to focus non-scattered light travelling along the incident beam axis onto the mirror;
• and the second condensing lens is configured to receive the scattered light from the first condensing lens and to focus the scattered light onto the first photodetector;
• and wherein the mirror is arranged along the incident beam axis between the first and second condensing lenses and is configured to reflect the non-scattered light away from the first photodetector;
• (e) determining, by a processor an intensity of scattered light collected by the first photodetector, and a corresponding representative amount or concentration of bacteria particles present in the sample;
• (f) repeating, by the processor, the determining step at a series of pre-determined intervals;
• (g) determining, by the processor, changes in the representative amount or concentration of bacteria in the sample as a function of time;
• and
• (h) determining, by the processor, susceptibility of the bacteria in the sample to the drug used to dose the sample based on the determined changes in the representative amount or concentration of bacteria in the sample as a function of time.