Septum-Based Sample Injection Device for Biochemical Analysis
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Solution Overview
Problem
Conventional sample injection devices for biochemical analysis experience flow disturbances and injection shocks due to pressure fluctuations when shifting between sample drawing and injection positions, and require separate washing units that complicate downsizing and maintenance.
Innovation Solution
A sample injection device with septa forming the upper and lower walls at the injection position, a cylindrical needle that moves vertically through these septa, and a needle moving unit that positions the needle for sample drawing and injection, integrated with a washing mechanism at an intermediate position, allowing for seamless sample injection without shocks and reduced washing liquid consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate needle washing position is provided, then washing efficiency is improved, but device size increases and washing liquid consumption increases
Solution Approach 1:
The washing function is merged with the sample injection function by integrating the washing mechanism into the injection unit. The needle washing is performed at an intermediate position within the injection unit rather than requiring a separate washing station, thereby combining multiple functions into one compact structure.
Solution Approach 2:
The injection unit is designed to perform multiple functions: sample injection and needle washing. By making the injection unit multi-functional, the device eliminates the need for separate washing units, reducing overall device size while maintaining washing efficiency.
2Reliability
If a separate needle washing position is provided, then washing efficiency is improved, but washing liquid consumption increases
Solution Approach 1:
The washing function is merged with the sample injection function by integrating the washing mechanism into the injection unit. The needle washing is performed at an intermediate position within the injection unit rather than requiring a separate washing station, thereby combining multiple functions into one compact structure.
Solution Approach 2:
Instead of providing extensive washing liquid flow from a separate washing unit, the invention uses a localized washing mechanism that applies washing liquid precisely where needed (at the needle tip within the injection unit), reducing overall washing liquid consumption while maintaining effective cleaning.
3Measurement precision
If constant flow rate control is implemented to prevent injection shock, then analysis precision is improved, but analysis speed decreases due to control response lags
Solution Approach 1:
The needle is moved to an intermediate position and sample washing is performed before the actual sample injection. This preliminary action prepares the system in advance, allowing the injection to proceed smoothly without requiring complex real-time flow rate adjustments, thus maintaining both precision and speed.
Solution Approach 2:
An intermediate position is introduced between the sample drawing position and the final injection position. The needle moves to this intermediate position for washing, and then proceeds to injection. This intermediate step acts as a mediator that separates the washing and injection operations, allowing both to be performed efficiently without compromising analysis speed or precision.
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
The device prevents injection shocks, enables precise and high-speed analysis, and allows for downsizing of the device by eliminating the need for separate washing units and reducing washing liquid volume, while maintaining efficient needle washing.
Implementation Method 1
a measurement pump (29) connected with the needle (27) on a side of a base end section thereof and configured to carry out drawing when the needle (27) is positioned at the sample drawing position and carry out discharge when the needle (27) is positioned at the sample injection position
Data Source
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AI summary
When injecting a sample into carrier-liquid channels (3A and 3B), injection shock is prevented. Septa 13 and 14 constitute the upper wall and the lower wall of a sample injection part (11) of the carrier-liquid channels (3A and 3B). A needle (27) can vertically penetrate the septum (13) on the upper wall side and also penetrate the septum (14) on the lower wall side. A needle moving unit (28) induces the needle (27) to penetrate the septum (14) on the lower wall side and induces the tip of the needle to face the inside of a sample vessel (26). A measurement pump (29) is operated for drawing and as a result a sample is drawn into the needle (27). Next, the needle (27) is extracted from the septum (14) on the lower wall side, the tip of the needle is induced to face the inside of the sample injection part (11), the measurement pump (29) is caused to discharge and as a result the sample within the needle (27) is injected.