Patent ID: 8105288

Claim:
A catheter insertion assembly comprising: a guide dilator comprising a hub at a dilator proximal end; a rigid guide needle slidably mounted within the dilator and comprising a distal piercing end, an axial bore, and a needle proximal end; a spring-loaded actuator urging the needle proximally relative to the dilator; and, a water triggered detent positioned between the needle and dilator hub preventing the needle from sliding proximally; wherein, in a first position, the distal piercing end of the needle extends out from a distal end of the dilator; wherein, in a second position, the distal piercing end of the needle is retracted within the bore of the dilator; and, wherein, the assembly is configured so that on contact with an aqueous fluid flowing from the needle axial bore, the detent allows the needle to slide proximally relative to the dilator in response to the urging of the actuator.