Patent attributes
Embodiments disclosed herein are directed to apparatus and methods for a stepped needle for an intraosseous device that uses the outer surface of the bone cortex as a reference point. Since the thickness of the bone cortex does not vary significantly between patients, the accuracy of needle placement can be improved. The device includes a needle with a stepped increase in outer diameter disposed along the needle shaft. The abrupt change in outer diameter provides a substantial increase in insertion force. In embodiments, the stepped increase prevents any further insertion into the bone cortex. Embodiments include a tapered needle lumen for medullary access confirmation and an overtube that is rotatably and slidably engaged to protect surrounding tissues and prevent needle stick injuries. Further, a needle hub can be rotatable or slidable, and can transition an overtube to an extended position to prevent accidental needle stick injuries.