PROBLEM TO BE SOLVED: To provide a biopsy needle for collecting a cellular tissue of an examinee in which the cutting of the cellular tissue is made reliably and the cut cellular tissue is held in the inside of the biopsy needle and collected.SOLUTION: A biopsy needle includes a solid-state inner needle 2 and a hollow outer needle 3 with the inner needle 2 movably fitted inside. The biopsy needle relatively moves between a projecting posture where the distal end 2h of the inner needle 2 projects from the tip 3q of the outer needle 3 and a storage posture where the distal end 2h of the inner needle 2 is immersed from the tip of the outer needle 3. The distal end 2h of the inner needle 2 is formed of a through-hole 2i where a cutting unit 2k for cutting a cellular tissue of an examinee and a holding unit 2 m for holding the cut cellular tissue are formed. The through-hole 2i is expanded and transformed radially outward by receiving a body temperature of the examinee when the distal end 2h of the inner needle is in the projecting posture, and is formed of a shape memory alloy so as to be pressed by the outer needle 3 and contracted and transformed radially inside in the storage posture while having a gap capable of containing the cut cellular tissue.SELECTED DRAWING: Figure 3COPYRIGHT: (C)2016,JPO&INPIT【課題】被検者の細胞組織を採取するための生検針を、確実に細胞組織の切断ができるようにするとともに、該切断された細胞組織を生検針内部に保持して採取する。【解決手段】、生検針を、中実状の内針2と内針2が移動自在に内嵌する中空状の外針3とを備えたものとし、内針2の先端部2hが外針3の先端3qから突出する突出姿勢と、内針2の先端部2hが外針3の先端より没入する収納姿勢とに相対移動し、内針2の先端部2hには、被検者の細胞組織を切断する切断部2kと、切断された細胞組織を保持する保持部2mとが形成された貫通孔2iが形成され、貫通孔2iは、内針先端部2hが突出姿勢のときには被検者の体温を受けて径方向外側に拡開変形し、収納姿勢のときには切断された細胞組織を内包できる空隙を有する状態で外針3に押圧されて径方向内側に収縮変形するよう形状記憶合金で形成されている。【選択図】図3
