US Patent 11311674 Medicament delivery device comprising a visual indicator

Disclosed herein is a pharmaceutical delivery device comprising a cartridge containing a fluid, the cartridge including a light pipe section which acts as a light pipe having an input location; and a light diffusing section optically coupled to the light pipe; and a light source optically coupled to the cartridge at the input location to the light pipe, such that at least some light from the light source entering at the input location is diffused at the light diffusing section.