An indicator dilution system includes a catheter configured to deliver an indicator to a patient, an injection device configured to deliver the indicator to the catheter, and a connector coupling the injection device to the catheter. The system also includes one or more sensors configured to acquire measurements from components of the system, which may be used to determine the start and end time of the injection of the indicator to the patient. For example, the one or more sensors may be configured to acquire signals relating to a state of the connector, which may be used to determine whether the connector is in an open state to enable flow of the indicator or in a closed state to reduce flow of the indicator.
