Systems, devices and methods for selectively blocking respiratory air flow to portions of a lung are disclosed. For example, one bronchus of a lung may be sealed off while another bronchus remains open to air flow. An endobronchial blocker may comprise an at least substantially transparent elongate member configured to facilitate real-time monitoring of the position of an inflatable member of the endobronchial blocker throughout a surgical procedure using a visualization or imaging device inserted within a main lumen of the endobronchial blocker.
