Optical Detection Assembly for Fluid Concentration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional optical detection assemblies for monitoring biological fluids face challenges such as inconsistent light transport due to varying refractive indices and tubing surface angles, and the limitations of single photodiode configurations when dealing with turbid media.
Innovation Solution
An optical detection assembly that includes a light source, a light detector array with multiple photodiodes, and a controller that generates a scattering profile based on the intensity of light received by each detector. The controller calculates the slope of the rising and falling edges of the scattering profile to determine the platelet mass index (PMI) and substance concentration in the fluid.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single photodiode is used to detect light, then the device complexity is reduced, but the measurement precision deteriorates because light transmitted through turbid media is dispersed and cannot be fully received at a single location
Solution Approach 1:
The light detection function is segmented across multiple photodiodes arranged in an array, with each photodiode detecting light at a different spatial location. This segmentation allows the system to capture the dispersed light pattern from turbid media while maintaining overall detection accuracy.
Solution Approach 2:
The detection system transitions from a single-point detection (0D/1D) to a multi-point spatial array (1D/2D), adding a spatial dimension to the measurement. This dimensional expansion enables capture of the light dispersion pattern across multiple positions, improving measurement precision for turbid media.
2Ease of operation
If conventional optical detection is used through flexible plastic tubing, then the ease of operation is improved, but the measurement precision deteriorates due to varying refractive indices and inconsistent tubing surface formation affecting light transport
Solution Approach 1:
A light guide or optical waveguide is introduced as an intermediary component between the light source and the fluid sample. This intermediary provides a stable, controlled optical path that eliminates the variability introduced by flexible tubing surfaces and refractive index changes, thereby improving measurement precision while maintaining operational ease.
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
This approach provides a non-invasive, accurate method for determining the PMI and substance concentration in biological fluids, overcoming the limitations of conventional systems by utilizing a light detector array and advanced signal processing techniques.
Implementation Method 1
light transmitted through turbid media (e.g., blood or a blood component) will be dispersed
Implementation Method 2
the transport of light into the tubing lumen may vary according to Snell's Law depending on the refractive indices of the materials and incident light angles
Data Source
Figure 1
Figure 2
Figure 2A
AI summary
An optical detection assembly for monitoring a fluid includes a light source, a light detector array, and a controller. The controller receives signals from the light detector array that are indicative of the intensity of light received by the light detector array after the light has passed through the fluid. The controller generates a scattering profile based on the signals, with the scattering profile including rising and falling edges each having a slope. The controller calculates one or both slopes and determines the platelet mass index (for a platelet-containing fluid) and/or the concentration of a substance in the fluid based on said slope(s). The optical detection assembly may also be used to analyze a reference fluid having a known concentration of the substance, with signals received by the controller when analyzing the reference fluid being a factor when determining the concentration of the substance in the fluid of interest.