A variety of steerable needles, lancets, trocars, stylets, cannulas and systems are provided for examining, diagnosing, treating, or removing tissue from a patient. The steerable needles, trocars, stylets, cannulas and systems also provide a platform for delivery of target materials, such as therapeutics, biologics, polymers, glues, etc., to a target site. An embodiment of the invention includes a steerable device for use in accessing target site in a patient comprising: a steerable member adapted to penetrate tissue; and a steering mechanism adapted to be operated by a user to apply a bending force to bend the steerable member to access the target site.