Orthogonal Laser Single Detection Path for Flow Cytometer Scatter
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Solution Overview
Problem
Current flow cytometers and cell sorters require separate optical detection paths for measuring forward and wide angle light scatter, making the measurement system more complicated and prone to distortion due to undulations in the fluid jet.
Innovation Solution
The use of multiple lasers with different wavelengths and a single detection path, where the lasers are mounted orthogonal to each other, allowing for spectral separation of forward and side scatter signals before detection, reducing distortion by intersecting close to the nozzle and eliminating the need for additional collection optics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate optical detection paths are used for measuring forward and wide angle light scatter, then measurement capability is improved, but device complexity increases
Solution Approach 1:
The patent combines separate optical detection paths for forward angle light scatter (FALS) and wide angle light scatter into a single integrated detection path. The system uses a single detector that receives both FALS and wide angle light scatter signals through one optical path, eliminating the need for separate detection systems while maintaining measurement capabilities for both scatter angles.
Solution Approach 2:
The single optical detection path is designed to perform multiple functions: it detects both forward angle light scatter and wide angle light scatter signals. The detector system is configured to receive and process both types of scatter measurements through the same optical path, making the detection system universal rather than specialized for a single measurement type.
2Stability of the object's composition
If measurement is performed more than a few hundred microns from the nozzle exit, then stable particle flow is achieved, but light scatter measurement accuracy deteriorates due to jet undulations
Solution Approach 1:
The patent positions the laser interrogation point and detection system to perform measurements at the optimal location in the fluid jet, close to the nozzle exit where particles are still stable but before undulations significantly distort the light path. This preliminary measurement approach captures accurate scatter signals before the harmful jet undulations develop fully.
Solution Approach 2:
The patent introduces a specifically designed optical detection path that acts as an intermediary between the particle-laden fluid jet and the detectors. This intermediate optical system is configured to minimize the impact of jet undulations on measurement accuracy, allowing stable particle flow conditions to be maintained while achieving accurate light scatter measurements.
3Adaptability or versatility
If multiple spatially separated laser interrogation points are used for fluorescence measurements, then fluorescence detection capability is improved, but additional collection optics are required increasing device complexity
Solution Approach 1:
The patent merges the detection of scattered light and fluorescent light into a single integrated optical detection path. The same detection system that measures FALS and wide angle light scatter also detects fluorescence signals, eliminating the need for separate collection optics for fluorescence measurements while maintaining multi-functional measurement capability.
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 configuration simplifies the optical measurement system, reduces distortion, and allows for accurate discrimination between different types of particles based on scatter measurements, as demonstrated by clear distinguishability of lymphocytes, monocytes, granulocytes, and other samples.
Implementation Method 1
Forward angle light scatter (FALS) is measured at small angles, typically less than about 15 degrees, from the propagation axis of the incident light beam. FALS is largely described by Mie scattering theory
Implementation Method 2
Wide angle light scatter is measured at relatively large angles from the propagation axis of the incident beam. Wide angle light scatter is largely described by Rayleigh scattering theory
Implementation Method 3
a collection optic having an optic axis; wherein the optic axis and the forward source axis are selected from the group consisting of: parallel and collinear, such that the collection optic receives both forward angle light scatter and side scatter light
Implementation Method 4
The use of multiple lasers with different wavelengths and a single detection path, where the lasers are mounted orthogonal to each other, allowing for spectral separation of forward and side scatter signals before detection
Data Source
AI summary
The various embodiments disclosed herein utilize multiple lasers that have different wavelengths and a single detection path. The lasers are mounted orthogonal to one another so that one laser will provide a forward angle light scatter (FALS) signal in the detection path, and one laser will provide a side scatter signal in the detection path (i.e., the single detection optics are approximately in-line with the FALS laser and approximately orthogonal to the side scatter laser). The single detector path spectrally separates the forward and side scatter signals prior to applying them to their respective detectors for measurement.