Separating Element Sealing Edge Positioning
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Solution Overview
Problem
Existing separating bodies for blood collection tubes often allow small amounts of the denser phase to mix with the lighter phase before reaching the sealing position during centrifugation, leading to contamination and loss of the lighter phase for medical analysis.
Innovation Solution
The separating body is designed with a sealing edge that maintains a predetermined distance above its center of gravity, ensuring precise positioning at the phase boundary between blood serum and blood clot, with a distance of 0.05 mm to 4 mm, preferably 1 mm to 3 mm, to prevent mixing while minimizing the loss of the lighter phase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the separating body is positioned close to the phase boundary to minimize loss of the lighter phase, then the quantity of the lighter phase is improved, but the risk of contamination increases
Solution Approach 1:
The separating body is pre-positioned with its sealing edge at a predetermined distance above the center of gravity, creating a safety margin before the centrifugation process begins. This preliminary positioning ensures that during centrifugation, the separating body will reach the phase boundary without allowing the denser phase to mix with the lighter phase, thus preventing contamination while minimizing loss.
Solution Approach 2:
The invention changes the positional parameter of the sealing edge relative to the center of gravity, establishing a specific distance relationship (predetermined distance above center of gravity). This parameter change creates a safety buffer that prevents the separating body from allowing phase mixing during centrifugation, thereby reducing contamination risk while maintaining efficient separation.
2Object-affected harmful factors
If the sealing edge is positioned at a large distance above the center of gravity to prevent contamination, then the contamination risk is reduced, but the loss of the lighter phase increases
Solution Approach 1:
The invention optimizes the positional parameter by establishing a predetermined distance relationship between the sealing edge and center of gravity. This specific parameter setting creates an optimal balance: the sealing edge is positioned high enough to prevent contamination during centrifugation, but not so high as to cause excessive loss of the lighter phase, thus resolving the contradiction between contamination prevention and phase preservation.
3Ease of manufacture
If the separating body uses a simple structure without precise geometric constraints, then the ease of manufacture is improved, but the positioning precision at the phase boundary deteriorates
Solution Approach 1:
The separating body employs an asymmetric geometric design where the sealing edge is positioned at a predetermined distance above the center of gravity. This asymmetric configuration provides inherent positioning precision during centrifugation without requiring complex manufacturing processes. The asymmetric shape creates a natural reference point that guides the separating body to the correct phase boundary position, achieving precision through simple geometric asymmetry rather than complex constraints.
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 design effectively prevents contamination and ensures that the lighter phase is preserved for analysis by maintaining a safe distance between the sealing edge and the phase boundary, optimizing the separation process.
Implementation Method 1
Under the action of the centrifugal force, the separating body is released from its initial position and moves into a sealing position
Implementation Method 2
Because the density of the entire separating body is in a value range between the density of the blood serum and the density of the blood clot, the separating body automatically positions itself exactly at the phase boundary between blood serum and blood clot
Implementation Method 3
the lighter blood serum floats on the blood clot
Data Source
Figure 1a~1b
Figure 2
Figure 3
AI summary
The invention relates to a separating element (100) for separating a first from a second phase of a liquid in a tubular container. The separating element has a float (110) made of an elastic material and having a circumferential sealing edge (112), and at least one ballast body (120) fixed to the underside of the float. The density of the ballast body is greater than the density of the float, and the density of the whole separating element lies in a value range between the density of the first phase and the density of the second phase of the liquid. In order to reliably prevent the penetration of parts of the second phase of the liquid into the region above the separating body within the tubular container when the separating body moves into the sealing position and is positioned there, according to the invention, the sealing edge of the float is formed at predefined distance (d) greater than zero above the centre of gravity (SG) of the whole separating element.