The system, which uses AVT’s Marlin F-046B camera combined with software based on National Instruments’ LabVIEW platform, can capture 80,000 images per hour using a short exposure time that prevents blurring.
AVT worked with fellow Germany-based firm Boehringer Ingelheim (BI) to develop the system, applying it to a manufacturing process whereby a precise quantity, 5.5mg, of a micronized powder had to be loaded into capsules.
BI senior scientist Peter Stöckel set out the scope of the challenge, explaining that: “One capsule leaves the filling machine every 45 ms, put another way, the capsules move at a speed of 1.5 m/s.
“[This] means that 22 capsules per second must be captured [by the camera],” continued Stockel, adding that “to avoid motion blurring, the exposure time cannot exceed 80 µs.”
He added that: “We’re very satisfied with the AVT camera. In continuous operation, it gives us sharp images that are indispensible for reliable evaluation.” The drugmaker has already added the new imaging system to several of its production lines.
The machine
To trial the unit BI installed it in the assembly process at its plant in Ingelheim, Germany. The machine was positioned in the assembly line after the filling but before the sealing of the capsules. This allowed it to photograph the open capsules.
Since the camera cannot be positioned over the capsules it images their contents via a tilted mirror. Imaging is supported by a LED flash unit which illuminates the capsules from below.
Captured images are transmitted to an industrial PC via a FireWire connection. The LabVIEW software, programmed by BI, first analyses the images to detect whether the capsule contains any powder at all.
Having established the presence of powder the software analyses the silhouette of the powder cylinder to derive the volumes and amounts of active ingredient in the capsule.