Retractable-needle cannula insertion set with refinements to better control leakage, retraction speed, and reuse

Abstract

Leakage of blood from the insertion set, during and after safety-needle retraction, is suppressed by components that receive and retain flash blood for viewing--notwithstanding forces developed within the device in retraction. One preferred such system includes a flash chamber that moves with the retracting needle, within a hollow handle, carrying a relatively high flow-impedance element which allows air exhaust from the chamber into the handle to admit flash blood--but isolates blood in the chamber from retraction-generated increase in air pressure in the handle. Energy-absorbing components control or compensate for retraction speed, to provide quiet smooth retraction--while yet enabling use of ample retraction force to make retraction reliable. Among several energy absorbing systems disclosed is a preferred one that includes a viscous material introduced within the hollow handle to damp the retracting motion; and an injection port to facilitate introduction of the viscous material. Needle reuse, and concomitant risk of spreading disease, are avoided through components that deter needle redeployment--by deterring access to or forward motion of the needle, or trigger reengagement.

Dependencies are inferred from the claim text.