Biological Sample Imaging Device with Flow Reversal for Particle Dispersion
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Solution Overview
Problem
In biological sample imaging, large-sized particles such as epithelial cells and urinary casts in urine samples are concentrated at the downstream end of a liquid flow channel, leading to overlap and difficulty in individual particle reflection in images, while setting the imaging range upstream may result in insufficient particle presence.
Innovation Solution
A biological sample imaging device and method that uses a syringe pump to control the flow of the sample, temporarily reversing the pump to disperse large particles back upstream and then refilling the imaging cell to ensure a sufficient and moderate dispersion of large particles within the imaging range, preventing overlap and ensuring adequate particle presence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the imaging range is set at the downstream end portion where large-sized particles are concentrated, then the density of particles increases and particles can be efficiently reflected in images, but large-sized particles overlap each other and it becomes difficult to reflect individual particles in images
Solution Approach 1:
The pump operation is made dynamic by alternating between forward and reverse directions. The pump first operates forward to concentrate particles at the downstream end, then reverses to disperse them upstream, creating a time-varying particle distribution that achieves both high density and good dispersion in the imaging range
Solution Approach 2:
The pump performs periodic forward and reverse operations. During the forward phase, particles are concentrated; during the reverse phase, particles are dispersed. This periodic action creates optimal particle distribution conditions for imaging by cycling through concentration and dispersion states
2Manufacturing precision
If the imaging range is set on the upstream side to avoid particle overlap, then individual particles can be clearly imaged, but a sufficient number of large-sized particles may not be present within the imaging range
Solution Approach 1:
The pump performs preliminary forward operation to concentrate particles at the downstream end before the imaging phase. This preliminary concentration action ensures that when the pump reverses and fills the imaging cell, a sufficient number of particles are available to be dispersed into the imaging range while maintaining adequate density
3Extent of automation
If the biological sample is caused to flow through the liquid flow channel, then automation of the test is achieved, but axial concentration effect causes large-sized particles to gather around the center axis and flow at high speed to the downstream side
Solution Approach 1:
Instead of continuously flowing the sample forward which causes axial concentration, the pump operation is inverted by periodically reversing direction. This reverse operation counteracts the axial concentration effect by pushing particles back upstream, dispersing them from the center axis region and achieving more uniform distribution while maintaining automation
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 allows for clear imaging of individual large particles, improving the accuracy and reliability of urine tests by maintaining a sufficient number of large particles within the imaging range without overlap, enhancing diagnostic capabilities.
Implementation Method 1
a pump controller 20c that causes the pump 24 to perform: a first operation of causing the biological sample 104 to flow in a forward direction, and moving a downstream end 104a of the biological sample 104 to a first position A; and a second operation of causing the biological sample 104 to flow in a reverse direction, and moving the downstream end 104a of the biological sample 104 to a second position B
Implementation Method 2
an axial concentration effect acts on the particles in the biological sample. That is, according to fluid dynamics, the flow rate of the biological sample increases as the biological sample approaches the center axis of the liquid flow channel, and the particles in the biological sample gather around the center axis of the liquid flow channel, where the flow rate is highest
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
Provided is a biological sample imaging device and a biological sample imaging method that are capable of disposing a sufficient number of large-sized particles in a biological sample so as to be moderately dispersed within an imaging range. The biological sample imaging method includes: a first step of introducing a biological sample (104) containing particles into a liquid flow channel (40); a second step of causing the biological sample (104) introduced into the liquid flow channel (40) to flow in a forward direction; a third step of causing the biological sample (104) to flow in a reverse direction after the second step; and an imaging step of taking, in an imaging cell (14), images of the particles contained in the biological sample (104) that remains in the liquid flow channel (40) after the third step.