US Patent 8348896 Patency check with pressure monitoring

A patency check protocol (150) for evaluating a patency check injection (156) is disclosed. The protocol (150) incorporates a pressure standard (152) (e.g., a pressure threshold; a target pressure curve). A pressure associated with the patency check injection is monitored (160) and compared against this pressure standard (164). If a first condition is identified (166) (e.g., if the pressure threshold is reached; if the monitored pressure deviates from the target pressure curve by more than a certain predetermined amount), one or more actions may be undertaken (168) (e.g., one or more notifications or alerts may be issued; the flow rate may be reduced for the patency check injection; the patency check injection may be suspended/terminated).