Puncture device

Abstract

A puncture device is provided that does not allow an outer needle to collapse or rise at the time of puncture and exhibits small puncture resistance. A puncture deviceincludes: a hollow outer needle; an outer needle hubprovided at a proximal end portion of the outer needle; a hollow inner needleinserted into the outer needlefor use; and an inner needle hubprovided at a proximal end portion of the inner needle. The inner needleincludes, from the distal side, a sharp needlepoint, a small diameter portionhaving an almost uniform outer diameter; an intermediate portionformed as a tapered portion which is progressively increased in outer diameter as it goes toward the proximal end; and a larger diameter portionhaving inner and outer diameters larger than inner and outer diameters, respectively, of the small diameter portion. If the puncture deviceis assembled, the needlepointis most projected from the distal openingof the outer needleand the proximal end of the small diameter portionand the distal end of the large diameter portionare located inside the outer needle. The inner diameter of the outer needleat a portion Lwhere the outer needlecovers the small diameter portionof the inner needleis smaller than the large diameter portionof the inner needle