A needle for use in taking a bone marrow biopsy comprises a hollow tube having a front end portion formed to a reduced diameter by swaging. The front end is tapered by means of a number of circumferentially-spaced facets, forming a cutting edge. A tapering transition portion, between the main portion...http://www.google.es/patents/US6890308?utm_source=gb-gplus-sharePatente US6890308 - Bone marrow biopsy needle
