Instead of having to combine several components for each analyzer, developers wanted to have a modular, universal dosing system. In developing such a system, fluid technology experts used proven and tested valves and designed their own special parts to meet all requirements.
Spanish company Biosystems S.A. has been developing and producing reliable analyzers for testing laboratories around the world since the early 1980’s. Employees gave themselves a motto when they developed the new biochemical analyzer BA400: follow the smart efficiency principle.
The analyzer is used to test human blood samples at the point of care and to record chemical parameters, and it has an optical, LED-based light system to measure turbidity. The fluids needed for the analysis have to be dosed accurately in the analyzer. So Biosystems turned to the fluid specialists at Bürkert Systemhaus in Ingelfingen, Germany, to develop a customized solution. What makes the solution so special is that it has a modular design, which allows it to be used not only in the new analyzer, but also in the other products from the Spanish manufacturer.
The two partners have already been working together for years. For previous devices, Bürkert supplied a multitude of different components, which took a certain amount of work for provision and maintenance. To be able to work with greater cost-efficiency and flexibility, the Biosystems engineers decided to develop a dosing unit that is intended to work not only with the new blood analysis systems designed for high flow rates, but also universally with all analyzers of the company’s diverse product portfolio. Reliability and accuracy for the clinical tests had to be maintained, of course. For the analyses, quantities of 2 µl have to be dosed accurately, an amount that is so small it is hard to see with the bare eye.
The technical challenge in implementing this plan was enormous. The complete dosing unit consists of five integrated components: the injection unit, two valves, a pressure sensor, and a filter on a transparent injection molded plastic part. Additionally, the number of dosing units in the analyzer changes with each version of the various analyzers. For this reason, it became quickly clear that the new solution would have to have a modular design. Such would allow the dosing unit to be used as an individual unit in a device type or in any number of ones.
Biosystems engineers used the expertise and experience of Bürkert Fluid Control Systems to achieve reliably the extremely high dosing precision needed in microfluidics technology for fluid control in the smallest space possible. The new development was based on the type-127 2/2-way and 3/2-way solenoid valves and the type-6628 3/2-way rocker solenoid valve from Bürkert. The two valves use the tested rocker technology that not only provides a full back pressure seal, but also is easy to rinse and has low internal volume. The system is guaranteed to work for precision dispensing of the smallest volumes of even aggressive media, while hardly allowing the temperature in the coil to rise.
The fluid specialists delivered more than just the solution for controlling fluid flows. An important function of blood analysis is the detection and prevention of air bubbles, which can falsify the results of the analysis. Therefore, Bürkert avoided using rough surfaces, dead spaces, and sharp edges when designing the dosing unit.
One particular challenge was a transparent inspection window that Biosystems requested be placed above the dosing unit and below the assembly containing the valves and pressure sensors. The window allows for visual inspection of the device. The specialists in Ingelfingen developed a special injection molded part made out of transparent plastic that has very high surface quality without sharp edges in the area of the dosing unit.
For users, the whole device is efficient to use: all they have to do is put the required samples and reagents in the analyzer. Then the fully automated analyzer will analyze up to 400 samples per hour. Since it uses little water and few reagents, it will work for eight hours at a time without interruption after the reservoirs have been filled.
The new one-for-all dosing unit can be used with the BA400 as well as with other analyzers, which is why it will be produced in large quantities. Biosystems takes advantage of the low costs per part, while Bürkert benefits from larger order quantities from the blood analysis specialists in Spain.
But the BA400 analyzer is more than just a technical innovation: its formal design and visual properties convinced the Red Dot jury to award the analyzer with the 2014 Red Dot Design Award for excellent product design, and the product won praise for its “dynamic curved lines, a compact and self-contained form, and environmental sustainability properties.”
Daniela Krahn Bürkert Fluid Control Systems, Ingelfingen, Germany
Additional information About Biosystems: www.biosystems.es/ At the Medica trade fair: Hall 01, Booth B12 About Systemhaus: http://www.burkert-usa.com/en/ At the Compamed trade fair: Hall 08b, Booth H07
Teilen:
