Liquid Sample Analysis Device Air Barrier Prevents Sheath Fluid Dilution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid sample analysis methods using flow cells face challenges in preventing dilution of the sample by sheath fluid, as the sheath fluid fills the aspirator and mixes with the sample before reaching the flow cell, affecting the accuracy of formed element observation.
Innovation Solution
A method and device that utilize a branch flow path to aspirate air from the aspirator, isolate the sheath fluid from the sample, and control the flow paths to ensure the sheath fluid does not mix with the sample until it reaches the flow cell, using pumps and switches to manage the fluid flow and prevent dilution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the aspirator is filled with sheath fluid before aspirating the liquid sample, then the flow path is properly primed and ready for operation, but the liquid sample becomes diluted by the sheath fluid before reaching the flow cell
Solution Approach 1:
Air is introduced as an intermediary substance between the sheath fluid and the liquid sample. The air column acts as a physical barrier that prevents direct contact and mixing between the sheath fluid in the aspirator and the liquid sample being aspirated, thereby eliminating dilution while maintaining proper flow path operation
Solution Approach 2:
The flow path is segmented into distinct zones: the sheath fluid-filled aspirator, an air column barrier, and the liquid sample stream. This segmentation creates isolated compartments that prevent unwanted mixing while allowing each substance to perform its intended function
2Productivity
If air is aspirated along with the liquid sample, then the aspirator can be emptied and prepared for the next sample, but air bubbles may flow into the flow cell and interfere with measurement
Solution Approach 1:
The harmful air bubbles are extracted and removed from the main sample flow path through a dedicated branch flow path. The branch path includes an air outlet that directs air away from the flow cell, preventing bubble interference while maintaining efficient sample processing
Solution Approach 2:
The system utilizes pneumatic pressure differentials created by the pump to selectively direct air and liquid through different flow paths. By controlling pressure zones, air is channeled through the branch path to the air outlet while liquid continues through the main path to the flow cell
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A liquid sample analysis method including communicating a specific flow path (30) with an aspirator (12) via a branch flow path (34), aspirating air (90) from the aspirator (12), aspirating a liquid sample (70) into the sample supply path (33) from the aspirator (12) so that an entire amount of the aspirated air (90) is accommodated in the branch flow path (34), communicating a sample extrusion path (32) with a sample port (22A), communicating a sheath fluid supply path (31) with a sheath fluid port (21A), and isolating the branch flow path (34) from both the sample supply path (33) and the specific flow path (30), extruding the liquid sample (70) in the sample supply path (33) so as to inflow into the sample flow path (22) by causing a sheath fluid (80) to inflow into the sheath fluid flow path (21) from the sheath fluid supply path (31) and causing the sheath fluid (80) to inflow into the sample supply path (33) from the sample extrusion path (32).