The present disclosure includes elongate members for positioning medical devices at a target site within a body lumen. In various embodiments, the elongate member may include one or more articulation joints for maneuvering, one or more transducers for localizing, and one or more lumens for delivering instruments to the target site. Some embodiments are particularly directed to a medical device that guides an operator to a target site, confirms the location of the target site, and enables a biopsy to be taken from and/or a therapy to be delivered to the target site. For example, a position tracking sensor may be utilized to guide the medical device to the target site, a phased array sensor may be utilized to confirming proper positioning at the target site, and a biopsy needle inserted through a lumen may be utilized to acquire a sample from the target site.