US Patent 7488308 Injector with bypass channel

An injector with a substance container defining a substance chamber configured for containing a substance to be injected, and an injection conduit configured for injecting the substance into a patient. A driver is associated with the substance chamber for driving the substance through the injection conduit. The injector also has a channel member defining a channel that has an open configuration in which the channel fluidly communicates the substance container to the injection conduit for the injection of the substance. The channel also has a closed configuration for blocking flow of any substance in the substance container therethrough to the injection conduit for inhibiting or preventing contact with the injection conduit prior to injection.