INDWELLING NEEDLE FOR EXTRACORPOREAL CIRCULATION

摘要

A seal member and outer cylinder needle (OCN) tip part for blocking, in a fluid-tight state, both external peripheral space (EPS) end parts formed between the external-peripheral-surface of an inner needle (IN) and internal peripheral surface of an OCN, for slidably holding the IN in close contact; an opening part formed on the OCN external-peripheral-surface and for intravascular communication with the EPS; an OCN connection part for communicating between the EPS and blood circuit end; an IN connection part for communicating between the IN internal space and other blood circuit end. The movable IN positioned between the projecting position where the tip part protrudes from the OCN tip and the housed position housing the tip inside the OCN. The IN punctures the blood vessel interior while holding the projecting position, and moved to the housed position after puncture allowing blood to extracorporeally circulate via the OCN and IN connection part.

主权项

1. An indwelling needle for extracorporeal circulation having a double tube structure including an outer needle made of a tube member having an opening formed on a tip end thereof, and an inner needle made of a tube member having a puncture portion formed on a tip end thereof and inserted in the outer needle, comprising:
a holding member for closing in a liquid-tight state respective ends of an outer circumferential space formed between an outer circumferential surface of the inner needle and an inner circumferential surface of the outer needle, and for closely holding the inner needle in a slidable state; a hole formed on an outer circumferential surface of the outer needle on a tip end side thereof in a position further rearward than the holding member, for communicating the inside of a blood vessel and the outer circumferential space when being punctured in the blood vessel; a first connection portion for communicating the outer circumferential space and one end portion of a blood circuit; and a second connection portion for communicating an inner space of the inner needle and another end portion of the blood circuit, wherein the inner needle is held by the holding member so as to move between a projecting position where an tip end portion thereof projects from a tip end of the outer needle and a housed position where the tip end portion thereof is housed in the outer needle, and the inner needle is punctured into the blood vessel while being held in the projecting position, and then moved to the housed position after being punctured so that blood extracorporeal circulation is able to be conducted via the first connection portion and the second connection portion.