US Patent 7534231 Needle tip guard for percutaneous entry needles

A needle tip protective device for use with percutaneous entry needles. In one embodiment, the needle tip protective device includes a needle guard slidably mounted on a hypodermic needle, the latter having a needle tip located at the distal end thereof, and a change of profile formed medially there along. The needle guard is movable along the hypodermic needle and engageable with the change in profile formed thereon. The engagement with the change in profile is configured to correspond with the ability of the needle trap to entrap the needle tip once the needle trap has advanced the sufficient distance distally along the hypodermic needle. In further refinements, the needle trap may be biased toward the distal needle tip of the needle.