Flow Cytometer Positional Velocity Sensing With Crosstalk Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Flow cytometers face challenges in accurately determining the positional velocity of particles in a flow stream due to laser crosstalk and baseline noise, which are exacerbated by temperature fluctuations affecting fluid viscosity, limiting precise electronic measurements and laser alignment.
Innovation Solution
The method involves irradiating particles in a flow stream with multiple lasers in spatially separated interrogation regions, using photodetectors to calculate positional velocity based on light detection, and adjusting laser timing and drop delays to minimize crosstalk and noise, thereby enhancing measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple lasers are used to irradiate particles in spatially separated interrogation regions, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The flow stream is divided into multiple spatially separated interrogation regions, each with its own laser and photodetector. This segmentation allows independent measurement of particle properties at different positions, enabling precise positional velocity determination while isolating the complexity into modular units.
Solution Approach 2:
The system transitions from single-point measurement to multi-point spatial measurement by adding the spatial dimension with multiple interrogation regions. This allows the system to measure not only particle velocity but also positional information, resolving the contradiction by utilizing dimensional expansion.
2Measurement precision
If laser timing is adjusted to minimize crosstalk, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The laser timing is made dynamic and adjustable rather than fixed. By allowing real-time modification of laser pulse timing, the system can optimize measurements to minimize crosstalk between interrogation regions while maintaining measurement precision.
Solution Approach 2:
Laser timing is pre-calibrated and optimized before actual particle measurement begins. This preliminary setup establishes optimal timing parameters that minimize crosstalk, reducing the need for complex real-time adjustments during operation.
3Reliability
If temperature fluctuations are compensated for, then reliability is improved, but device complexity increases
Solution Approach 1:
Temperature sensors provide feedback about thermal conditions in the flow stream, allowing the system to compensate for temperature-induced viscosity changes. This feedback mechanism maintains reliable velocity measurements without requiring complex active temperature control.
Solution Approach 2:
The system compensates for temperature effects by adjusting measurement parameters rather than maintaining constant physical conditions. By modifying how measurements are taken based on temperature conditions, reliability is improved without complex thermal control infrastructure.
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 reduces laser crosstalk and baseline noise, allowing for precise positional velocity determination and improved sorting accuracy, increasing particle sort yield and purity by dynamically adjusting laser delays and drop delays for each particle.
Implementation Method 1
the flow stream is irradiated with light. Variations in the materials in the flow stream, such as morphologies or the presence of fluorescent labels, may cause variations in the observed light
Implementation Method 2
the presence of fluorescent labels, may cause variations in the observed light
Implementation Method 3
detecting light from the irradiated particle by a first photodetector channel in the first interrogation region and by a second photodetector channel in the second interrogation region
Implementation Method 4
The drops containing particles of interest are electrically charged and deflected into a collection tube by passage through an electric field
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
Aspects of the present disclosure include methods for determining positional velocity of a particle in a flow stream of a particle analyzer. Methods according to certain embodiments include irradiating a sample having a particle in a flow stream of a particle analyzer with a first laser in a first interrogation region and a second laser in a second interrogation region, detecting light from the irradiated particle by a first photodetector channel in the first interrogation region and by a second photodetector channel in the second interrogation region, calculating a velocity of the particle in the flow stream based on the light detected by the first photodetector and by the second photodetector, determining a parameter of the particle in the flow stream and calculating a positional velocity of the particle in the flow stream based on the calculated velocity and the parameter of the particle. Systems and non-transitory computer-readable storage media configured to carry out the subject methods are also provided.