Blood Flow Passage Control Using an Air Layer for Aggregation Measurement
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Solution Overview
Problem
Existing methods face challenges in accurately controlling blood flow and preventing contact between rinse liquid and blood due to viscoelasticity issues, which affect pressure transmission and can lead to inaccurate erythrocyte aggregation measurements.
Innovation Solution
A measuring apparatus and method that uses a sensor to detect an air layer in the flow passage, forming a controlled air layer between the rinse liquid and blood to maintain accurate blood flow control and prevent direct contact, utilizing a tube pump with rollers to manage blood flow and a detection unit for erythrocyte aggregation measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a tube pump is used to move blood sample, then blood can be transported from storage unit to detection unit, but accurate control of blood flow position and speed becomes difficult due to viscoelasticity of the flow passage
Solution Approach 1:
A non-compressive fluid (rinse liquid) is introduced as an intermediary substance between the compressive fluid (air) and the blood sample. This intermediary fluid transmits pressure more effectively without compression, enabling accurate blood flow control. The rinse liquid fills the flow passage to replace air, thereby eliminating the pressure attenuation problem caused by air's compressibility while maintaining a barrier to prevent direct contact between blood and rinse liquid.
2Device complexity
If air is used in the flow passage, then the system remains simple, but pressure transmission is attenuated due to high viscoelasticity of air
Solution Approach 1:
The physical state of the fluid in the flow passage is changed from compressive (air) to non-compressive (rinse liquid). This parameter change eliminates compression effects and significantly improves pressure transmission efficiency. By changing the fluid type from gas to liquid, the system achieves reliable pressure transmission necessary for precise blood flow control without increasing device complexity.
3Stress or pressure
If rinse liquid is used to fill the flow passage, then pressure transmission improves, but contact between rinse liquid and blood may occur causing concentration variation
Solution Approach 1:
The flow passage is segmented into distinct zones using the non-compressive fluid as a separator. The rinse liquid creates a physical barrier that segments the air/blood interface, preventing direct contact between blood and rinse liquid while maintaining pressure transmission. This segmentation ensures that blood concentration remains unchanged while benefiting from improved pressure transmission through the non-compressive fluid medium.
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 control of blood flow and prevents contact between rinse liquid and blood, ensuring accurate erythrocyte aggregation measurement by forming a controlled air layer, thus allowing for reliable syllectogram analysis.
Implementation Method 1
The tube pump sucks a blood sample by operating in such a manner that rollers press a tube when they rotate in the circumferential direction
Implementation Method 2
a sensor which detects switching from a liquid to a gas in the flow passage
Implementation Method 3
measuring an optical density variation (called a syllectogram) that occurs at that time
Data Source
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AI summary
A measuring apparatus (1) includes a storage unit (10) in which the blood sample is stored, a pump (20) which sucks the blood sample from the storage unit, a flow passage (30) which communicates with the storage unit and through which the blood sample or a rinse liquid flows when sucked by the pump, a detection unit (50) including an irradiation unit which irradiates the flow passage with light and a light detecting unit which detects light that has been emitted from the irradiation unit and has transmitted through or been reflected from the flow passage, a sensor (60) which is disposed between the storage unit and the detection unit and detects switching from a liquid to a gas in the flow passage, and a control unit (70) which controls a stop of driving of the pump.