Automated Liquid Sampling Device with Clutch-Driven Cannula
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The variability in size and shape of vials containing bodily fluids hinders mechanization of liquid sample transfer to cuvettes or wells, as existing solutions struggle to accommodate different vial heights and the self-sealing nature of rubber bungs complicates cannula withdrawal.
Innovation Solution
A device with a cannula and abutment mechanism, driven by a transmission system, that aligns with vials of varying heights, engages the closure element, and uses a clutch mechanism to decouple drive elements, allowing simultaneous movement of the cannula and abutment to facilitate sample withdrawal or addition without displacing the vial or closure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a fixed-height abutment device is used to hold down the bung during cannula withdrawal, then the cannula can be withdrawn without displacing the vial or closure, but the device cannot accommodate vials of different heights
Solution Approach 1:
The abutment device incorporates a movable platform that can be positioned at different heights to match the closure element position of vials with varying heights. The platform moves vertically along guide rails and is actuated by a positioning mechanism, allowing the same device to accommodate different vial heights while maintaining the holding function during cannula withdrawal
Solution Approach 2:
The abutment device is designed with adjustable height capability to serve multiple vial height requirements with a single device. The movable platform can be positioned to match different closure element heights, making the device universal for handling various vial sizes without requiring multiple fixed-height devices
2Productivity
If manual arrangement of vials by height is performed, then vials of similar height can be grouped together for mechanized processing, but this is time-consuming and often impossible due to the extensive variety of vial dimensions
Solution Approach 1:
The system uses adjustable-height abutment platforms that can dynamically adapt to different vial heights, eliminating the need for manual sorting. The platform height is adjusted automatically or manually to match each vial's closure element position, allowing mechanized processing of vials with varying dimensions without time-consuming pre-arrangement
3Reliability
If the rubber bung is made self-sealing to prevent leakage, then sample integrity is maintained, but the cannula engagement becomes too tight for easy withdrawal
Solution Approach 1:
The abutment device acts as an intermediary between the cannula and the self-sealing bung. By positioning and holding the bung from below, it provides a counterforce that balances the friction grip between the cannula and bung, enabling smooth cannula withdrawal without compromising the self-sealing property or requiring excessive force
Data Source
Figure 1
Figure 2
Figure 3~6
AI summary
Apparatus (1) for withdrawing respective liquid samples from vials (2) which are closed by closure caps (4) penetratable by a pointed cannula comprises a plurality of racks (7) for accommodating the vials (2). A device (10) comprising a housing (25) is slideably carried on a gantry (9) which in turn is slideably carried on guide tracks (12) to provide two degrees of movement of the device (10) for selective alignment of the device (10) with the vials (2). An abutment member (43) which is vertically slideable in the housing (25) of the device (10) is driven by a second gearwheel (51) by a drive shaft (27) along which the housing (25) is slideably mounted through a first gearwheel (40) and a dog clutch (52). A cannula which is secured within a first gear rack (33) is driven upwardly and downwardly within the housing (25) by the first gearwheel (40) which is driven by the drive shaft (27). On engagement of the abutment member (43) with the closure cap (4) of the selected vial (2), the clutch (52) decouples the second gearwheel (51) from the first gearwheel (40) so that the cannula (28) is urgeable through the closure cap (4) into the vial (2) for withdrawing the liquid sample. The clutch (52) retains the second gearwheel (51 ) decoupled from the first gearwheel (40) until the cannula (28) has been withdrawn from the closure cap (4) in order to prevent displacement of the closure cap (4) during withdrawal of the cannula (28) therethrough.