Patent ID: 9072823
Filing Date: 2015-07-07
Classification: A61B,A61M

Abstract:
1. A medical device, comprising: (a) a body having a distal end, a proximal end, a length and a longitudinal axis; (b) a cutting cannula, mounted fixedly on the body and extending away from the distal end of the body, the cutting cannula having a longitudinal bore and a sharpened distal end; (c) a tubular stylet extending through the bore of the cutting cannula, the stylet having a proximal portion and a blunt distal end; (d) a stylet pusher disposed within the body and movable longitudinally with respect to the body, the stylet pusher being located with respect to the tubular stylet so as to urge the tubular stylet longitudinally within the bore of the cutting cannula toward the distal end of the cutting cannula; (e) a spring housed within the body and arranged to urge the stylet pusher in a distal direction with respect to the body; and (f) a selectively engageable and releasable locking mechanism operable first to lock the tubular stylet only in a distally extended position with respect to the body and thereby to keep the tubular stylet in a position in which the blunt distal end of the tubular stylet protrudes beyond the sharpened distal end of the cutting cannula and obscures the sharpened distal end of the cutting cannula when the locking mechanism is engaged, and, second, when the locking mechanism is unlocked, operable to allow both spring-urged extension of the tubular stylet toward a distal position and repression of the tubular stylet in a proximal direction sufficiently to expose the sharpened distal end of the cutting cannula, the locking mechanism including a latch receptacle including a transverse slot, defined in a wall of the body and defining a retaining surface, and an arm extending as a latching member from a flexible portion of the stylet pusher and extending selectively into the transverse slot so as to engage the retaining surface, thereby selectively engaging the locking mechanism.