Case Study In Full Flow of IV-bags
Automated visual inspection of infusion bags
Key benefits
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Shorter downtimes due to automated teach-in process
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Print inspection scalable on different products
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False rejects are minimized (<1%)
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Continuous process optimization
The automated visual inspection of infusion bags (IV bags) is a particular challenge in the field of medical technology and pharmaceutical production. With its cutting-edge machine vision systems, VITRONIC not only enables reliable quality inspection, but also ensures a simplified teach-in process and thus shorter downtimes such as at B. Braun headquarters in Melsungen, Germany.
The first project for quality testing of IV bags was carried out by VITRONIC for B. Braun about ten years ago. Since then, a continuous optimization of the production process took place, which was actively accompanied by VITRONIC.
Also with the latest project, the optical inspection of multi-chamber bags for artificial nutrition, there was a close cooperation with B. Braun. First, a specification sheet was drawn up containing all the requirements, for the Group. Then the Healthcare team in charge of the project conducted a feasibility study.
The visual inspection system used so far had reached its limits. This way, bags that were perfectly okay were rejected as defects.
In particular, the shape and printing of infusion bags posed a challenge for quality inspection. The inspection solution from VITRONIC provides a remedy and increases reliability and productivity in the process.
- 620Bags per hour can be inspected with the system, with less than 1% reject.
The large printing of our standardized three-chamber bag including multilingual layouts with small letters and strong waviness of the bag is a real challenge for visual inspection. Yet since the start of the new production process, the reject rate is less than one percent.
Fast automated teach-in
With this solution, the print template is first transmitted to the vision system in the form of a PDF containing the fixed print layout and the division of the fixed print into inspection regions (ROI). This information is then processed by the vision system using specially developed readout routines. The inspection regions are then used to create concrete inspection areas and the fixed print layout is converted into a statistical description.
Specially developed algorithms enable a filing correction of the current characters of each multi-chamber bag to the taught-in characters during the subsequent inspection via camera image and to convert these into a statistical description. Finally, the taught-in description and the defined quality limit values are exactly compared with the current description of the multi-chamber bags.
Thanks to the further developed filing correction of the characters, we can compensate all waviness and distortions and reliably check the characters printed on the multi-chamber bags with shorter downtimes.
A further challenge…
... represents the multilingual printing of the IV bags that has developed due to regulatory requirements. As a result, three times as much text can be placed in the available space as usual. This was only possible with small font sizes.
The solution
A 32-megapixel camera provides images in high resolution. This ensures that even the smallest letters can be reliably inspected. The division of the bags into three priority classes, each with of different fault tolerance to further minimize the reject rate.
Virtual tool box
An important component of the system solution provided for B. Braun is the high-performance evaluation software which has been especially developed by VITRONIC for printing inspection. This application is part of a virtual toolbox including various tools such as for codes reading or OCR (optical character recognition).
Depending on customer requirements, the individual tools can be individually compiled. The optimum combination of soft and hardware components enables the fast capture of a wide range of information.
In the case of B. Braun, this also includes the wavy surfaces of the multi-chamber bags. For the project in Melsungen, a VITRONIC team from the subareas of development, construction, production, and technical documentation joint forces to deliver the solution. Furthermore, an extensive service package for B. Braun also included the training of the line and maintenance employees as well as a backup concept. After the previous inspection system has been replaced by the new system, the production line in Melsungen was qualified together with B. Braun and successfully started operation.
The test results, including the image above, can be called up live via the control keypad on the terminal.
- 0,9% of 1,402 bags in the above display were printed incorrectly.
