US Patent 7025746 Vascular access device

A vascular access system comprises a needle having a distal tip and a proximal fitting section and a dilator having a solid distal section connected to a solid proximal section and an annular recess therebetween, the dilator having a passageway so that the dilator is coaxially positioned around the needle. The needle has at least one opening positioned proximal to its distal tip so that, when the distal end of the needle enters a blood vessel, blood enters the annular recess to show the operator that access has been achieved. Optionally, a sheath having a distal tip, a proximal fitting section, and a lumen sufficient to coaxially fit over the dilator.