PT  - JOURNAL ARTICLE
AU  - Kaestner, Anders P
AU  - Roth, Jasminka
AU  - Gruenzweig, Christian
TI  - Real-Time Neutron Imaging to Detect Origin of Blocking in Drug Injection Devices
AID  - 10.5731/pdajpst.2015.006353
DP  - 2016 Jan 01
TA  - PDA Journal of Pharmaceutical Science and Technology
PG  - pdajpst.2015.006353
4099  - http://journal.pda.org/content/early/2016/04/13/pdajpst.2015.006353.short
4100  - http://journal.pda.org/content/early/2016/04/13/pdajpst.2015.006353.full
AB  - Non-destructive testing is a common method for root cause investigations of malfunction of mechanical devices, e.g. medical devices for drug dose delivery. Radiography is a method that has the advantage that it is possible to see through the sample. In this work we are using neutron radiography to observe drug distribution in drug injection devices during the injection process and as post injection examination. Using neutrons it is possible to show small amounts of liquid in capillaries and foam bubbles are shown with great contrast compared to metal and glass. The investigation has two parts optimized for high spatial and temporal resolution respectively. Using high spatial resolution it is possible to resolve the thin films of drug product in foam and even to detect the drug residues in the injection needle. Switching to high temporal resolution we demonstrate that it is possible to follow the injection process. Spatio-temporal data sets of the injection process were acquired using remotely triggered injection devices and a camera allowing sub-second frame rates. The motion analysis required the application of an edge preserving spatio-temporal denoising filter to improve the signal to noise ratio. After filtering it is possible to detect relevant edges and extract motion curves from the spatio-temporal data.