Abstract: One-handed operable biopsy needle instruments, employing combined spring driven stylets, and cannulas, capable of taking multiple specimens while the other hand is free, e.g. to manipulate an ultrasound probe are described. The particular biopsy needle instrument shown in detail has a pair of cannula and stylet compression springs, a pair of members directly engaged on the ends of the springs mounting respectively the cannula and stylet, and releasable holding means for holding the springs compressed until firing. The device that loads the stylet spring and a pivotal latch each can serve as a means for releasably holding the stylet spring. A latch is employed to releasably hold the cannula spring. Actuation of the stylet can cause sequential operation of the cannula through impact of the stylet-mounting member on the cannula latch.

Abstract: A biopsy needle instrument has selectable locking means to permit or prevent the projection of a cannula and a stylet and separate loading members allowing the cannula and stylet to be loaded separately and yet fired sequentially using a single button. Another embodiment of the invention permits the independent firing of the stylet and the cannula.