Droplet Delay Measurement Using Dual Laser Interrogation Points

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing sorting devices, such as flow cytometers, struggle to accurately calculate droplet delay time from a laser interrogation point to a separation point due to limitations in existing technologies, particularly for glass-pool-based systems where liquid flow fluctuations are not captured until exiting the nozzle.

Innovation Solution

A system and method using multiple laser sources and detectors to measure the time difference at specific interrogation points within and outside the nozzle system, combined with image processing and particle size considerations, to calculate droplet delay time accurately.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single laser interrogation point is used within the nozzle system, then the device structure is simple, but the droplet delay time cannot be accurately calculated because liquid flow fluctuations are not captured until exiting the nozzle

Engineering Contradiction:
Improvedroplet delay time measurementVSAvoidlaser and detector system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the measurement system into multiple laser sources (first and second laser sources) positioned at different locations, with corresponding detectors for each. This segmentation allows independent measurement at multiple interrogation points, enabling accurate calculation of droplet delay time by comparing phase differences between signals from different locations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extends the measurement from a single point to multiple spatial dimensions by placing laser interrogation points at different locations (within and outside the nozzle system). This multi-dimensional approach captures the liquid flow characteristics at various positions, enabling precise delay time calculation that accounts for flow dynamics throughout the system.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If multiple laser sources and detectors are used to measure time difference at multiple interrogation points, then droplet delay time can be accurately calculated, but the device complexity increases

Engineering Contradiction:
Improvedroplet delay time measurementVSAvoidlaser and detector system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes the laser and detector system multi-functional by using each laser source and detector combination not only for particle detection but also for measuring liquid flow phase. This universal approach allows the same hardware to serve dual purposes: characterizing particles and measuring flow dynamics, thereby reducing the need for separate measurement systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent uses the phase difference information obtained from multiple detectors as feedback to calculate and determine the droplet delay time. This feedback mechanism allows the system to continuously monitor and adjust measurements based on the temporal and spatial relationships between signals from different interrogation points, improving measurement accuracy while utilizing existing hardware capabilities.

Inventive Principle:
Principle #23Feedback

3Reliability

If droplet delay time is not accurately determined, then the sorting device cannot appropriately deflect droplets, but adding measurement systems increases device complexity

Engineering Contradiction:
Improvedroplet deflection accuracyVSAvoidmeasurement and calculation system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs preliminary measurement and calculation of droplet delay time using multiple laser sources and detectors before the actual sorting operation. By determining the delay time in advance through phase difference analysis of signals from multiple interrogation points, the system prepares the necessary timing information for accurate droplet deflection, ensuring reliable sorting while using a systematic measurement approach.

Inventive Principle:
Principle #10Preliminary action

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

Enables precise determination of droplet delay time, improving the accuracy of droplet deflection in sorting devices by considering particle size and nozzle configurations, enhancing the overall sorting efficiency.

Implementation Method 1

a first laser source is configured to emit a first laser beam to a liquid flow of the sorting device, wherein the first laser beam and the liquid flow intersect at a first laser interrogation point located in a nozzle system of the sorting device

Methodology Applied
Scientific EffectLight interaction with particles: Light

Implementation Method 2

a second laser source is configured to emit a second laser beam to the liquid flow, wherein the second laser beam and the liquid flow intersect at a second laser interrogation point located outside the nozzle system

Methodology Applied
Scientific EffectLight interaction with particles: Light

Implementation Method 3

the droplet delay time calculation unit is configured to calculate, on the basis of a time difference between a time when a particle in the liquid flow passes through the first laser interrogation point and a time when the particle passes through the second laser interrogation point, a first delay time for the liquid flow flowing from the first laser interrogation point to the second laser interrogation point

Methodology Applied
Scientific EffectTime of flight measurement: Time of Flight

Data Source

PatentEP4281750B1System and method for calculating a droplet delay time, and sorting device
Publication Date: 2025.07.23 BECKMAN COULTER BIOTECHNOLOGY (SUZHOU) CO LTD
  • EP4281750B1 patent drawingFigure 1
  • EP4281750B1 patent drawingFigure 2
  • EP4281750B1 patent drawingFigure 3

AI summary

The present application discloses a system and a method for calculating a droplet delay time in a liquid flow of a sorting device, and a sorting device. The system includes: a first laser source configured to emit a first laser beam to a liquid flow of a sorting device, the first laser beam and the liquid flow intersecting at a first laser interrogation point located in a nozzle system of the sorting device; a second laser source configured to emit a second laser beam to the liquid flow, the second laser beam and the liquid flow intersecting at a second laser interrogation point located outside the nozzle system; a first detector and a second detector which are respectively used for detecting emission, in response to the first laser beam and the second laser beam, of a particle in the liquid flow; and a droplet delay time calculation unit configured to calculate, on the basis of the time when the particle in the liquid flow passes through the first laser interrogation point and the time when the particle passes through the second laser interrogation point, a first delay time for the liquid flow flowing from the first laser interrogation point to the second laser interrogation point, and calculate, on the basis of the first delay time, a droplet delay time.