Catheter attachment for blood sampling

Claim 1

An attachment to be utilized in conjunction with a catheter and syringe, comprising: housing means, adapted to be fixedly secured to a catheter, comprising a housing wall formed as a thin-walled structure and fabricated of a resilient plastic material and fluid flow passageway means for fluidically connecting said housing means with a catheter when secured thereto; mounting means on said housing, adapted for mounting a syringe thereon and providing fluid connection therewith with said fluid flow passageway means; a sealing stylet reciprocatively disposed within said housing between two extreme positions for periodically blocking the flow of fluid through said fluid flow passageway means, said fluid flow to said housing being blocked when said stylet is disposed in said first position, and said fluid being permitted to flow to said housing and said mounting means when said stylet is disposed in said second position; handle means for manipulating said stylet between said two extreme positions; a control means for periodically blocking the flow of fluid from said fluid flow passageway means through said mounting means; and means for maintaining said stylet substantially sterile comprising normally closed slot means defined within said housing wall through which said means for manipulating said stylet projects; whereby said slot means is substantially closed, except within the immediate vicinity of said handle means, so as to maintain the interior of said housing substantially sterile.