Elliptical Reflector Light Collection for Bacterial Susceptibility Testing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for measuring optical properties of biological samples, particularly for determining bacterial concentration and susceptibility to drugs, are limited in their ability to efficiently capture scattered light and provide accurate, time-dependent measurements.
Innovation Solution
An optical apparatus comprising a light source, a first photodetector, a light collection arrangement that collects forward-scattered light within specific angles, and a processor to measure scattered light intensity and determine bacterial concentration over time, allowing for the assessment of bacterial susceptibility to drugs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional light collection methods are used, then the measurement can be performed, but the sample volume required is large and the measurement precision is insufficient
Solution Approach 1:
The patent employs a concave elliptical reflector with curved surfaces to collect and redirect scattered light. The elliptical geometry allows the reflector to concentrate light from specific scattering angles onto the photodetector, thereby improving measurement precision while requiring smaller sample volumes compared to conventional flat or non-elliptical light collection methods.
Solution Approach 2:
The light collection arrangement is designed to selectively collect light within specific scattering angle ranges (forward scattering) while rejecting light from other directions. This localized light collection approach improves measurement precision by focusing on the most informative light paths without requiring large sample volumes.
2Productivity
If integrating sphere light collection is used, then light collection efficiency is improved, but the device complexity increases
Solution Approach 1:
The patent extracts the essential light collection function from the complex integrating sphere design and implements it using a simpler concave elliptical reflector. This extracted function achieves high light collection efficiency for forward-scattered light without requiring the entire integrating sphere structure, thereby reducing device complexity while maintaining productivity.
Solution Approach 2:
Instead of using a complete integrating sphere that collects light from all directions, the patent segments the light collection function to only collect light within specific scattering angle ranges (forward scattering). This segmentation achieves sufficient light collection efficiency without the complexity of capturing all scattering directions.
3Quantity of substance
If the light collection arrangement collects light over a wide angular range, then more light is captured, but non-scattered light interferes with the measurement
Solution Approach 1:
The concave elliptical reflector is designed with specific geometric properties that allow it to selectively collect light from forward scattering angles while naturally rejecting non-scattered light traveling parallel to the incident beam. This local quality of light collection improves measurement precision by ensuring only relevant scattered light reaches the photodetector.
Solution Approach 2:
The asymmetric concave elliptical geometry of the reflector creates directional light collection characteristics that favor forward-scattered light while blocking non-scattered light paths. This asymmetric design enables the system to capture sufficient scattered light without the interference of non-scattered light, maintaining measurement precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The apparatus effectively captures a high proportion of forward-scattered light, enabling the use of smaller sample volumes while maintaining statistical significance, and provides accurate, time-dependent measurements of bacterial growth and drug susceptibility.
Implementation Method 1
a light source configured to emit light along an incident beam axis that, in use, intersects with a detection chamber of a sample container containing the drug-dosed sample, and to illuminate the drug-dosed sample contained within the detection chamber; a first photodetector configured to receive light scattered by particles in the sample
Implementation Method 2
a light collection arrangement configured to: collect light exiting the detection chamber that has been scattered in a forward direction by the particles 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
Implementation Method 3
a first photodetector configured to receive light scattered by particles in the sample; at least one processor configured to: measure an intensity of the scattered light received by the first photodetector
Data Source
AI summary
A device comprising an optical apparatus for monitoring bacterial growth of a drug-dosed liquid biological sample. A sample container port for receiving a sample container, in use, is provided in the device, the sample container having at least one detection chamber for containing the drug-dosed sample. The optical apparatus comprises 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. The optical apparatus comprises a first photodetector configured to receive light scattered by bacteria in the sample. The optical apparatus comprises 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. The optical apparatus comprises at least one processor configured to: measure an intensity of the scattered light received by the first photodetector; determine a corresponding representative amount or concentration of bacteria present in the sample based on the intensity of the scattered light; repeat the measuring and determining steps 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 determine a corresponding susceptibility of the bacteria in the sample to the respective drug.