Abstract: Identifying target anatomic locations in a subject's body, and delivering medicinal substances thereto, following transtissual progression (penetrating, cutting through body tissue) and reaching body tissue with medical device distal tip. Involves acquiring mechanical properties of body tissue. Exemplary medicinal substance is, or includes, a drug (anesthetic agent), and exemplary target anatomic location is epidural space in subject's body. Exemplary system includes: cannular member enclosing cannula lumen; pusher-probe having distal end in cannula lumen and positionable from retracted to protruding positions, wherein pusher-probe distal end protrudes out of cannula distal end; and extending mechanism including cam member, a follower shiftable from first to second stations on cam member, and plunger selectively traveling in cannula lumen while forcing relative motion between cam member and follower, wherein pusher-probe distal end repositions between retracted and protruding positions.

Abstract: A positioning device with sensing capacities is provided, which facilitates needle or catheter introduction into a body tissue or cavity and is configured to sense the types of encountered tissue. Using the epidural access procedure as an example, device and method designs are presented, which enable the sensing of needle entrance to the epidural space and anchoring of the cannula within the ligamentum flavum tissue to prevent puncturing of the dura mater. In case of tissue sensing by an expandable balloon, balloon fluid pressure and volume are used to indicate tissue and cavity characteristics encountered during the procedure. Device embodiments, device construction methods and treatment methods are provided.