The present invention relates to fitments for connecting medical devices, and in particular, to luer fittings having a textured contact surface.
A conventional luer fitting or fitment generally comprises a conically-shaped element which is adapted to form a relatively air-and-liquid tight seal when mated to a complementary fitting, as for example, a syringe tip to a catheter hub. The surface of the luer fitting which contacts the complementary fitting is ordinarily smooth. Such luer fittings are well known in the art, see International Standard Organization (ISO) 594/1-1986, and have been incorporated into a variety of medical devices.
Once connected, it is important that luer fitments do not become accidentally disengaged during a medical procedure. Such accidental disengagement could result in fluid loss or fluid contamination, which in turn, could have adverse consequences for a patient.
Under most circumstances, the frictional fit between conventional mated luer fitments is sufficient to prevent accidental disengagement of the fitments. However, when fluid contaminants or wetting agents are present between the contact surfaces of mated luer fittings, the fluid contaminants tend to act as a lubricant. The lubricating nature of the fluid contaminants diminishes the frictional force, otherwise known as "engagement force", which must be overcome to separate the luer fittings, and thus increases the possibility of accidental disengagement of the fittings.
Various solutions have been proposed in the prior art to overcome the problem of fluid contaminants lubricating luer fittings. For example, ISO 594-2 1991-05-01 teaches luer fittings with interlocking threads and engagement structure. To connect luer fittings of this design, a medical service provider brings the fittings together, and then secures them with a twisting motion. While this may be a practical solution for many applications, it may be undesirable where rapid engagement and disengagement of the luer fittings is preferred.
U.S. Pat. No. 4,589,871 to Imbert teaches applying a coating on the exterior surface of a syringe tip (male luer fitment) to increase the roughness of the tip. It is stated therein that increasing tip roughness in this manner increases the frictional fit of mated luer components, making them harder to separate in comparison to identically sized conventional luer fittings. However, such coating processes may involve costly post-manufacturing application and quality control steps. Furthermore, for certain medical applications, it may be desirable to use a luer connector, which in addition to being resistant to the lubricating effects of fluid contaminants, also has a frictional fit which is substantially the same as identically sized conventional luer fittings.
Thus, there remains a need for a luer fitting resistant to the lubricating effects of fluid contaminants and a method of manufacturing the same. Optimally, such a luer fitting could be manufactured by a low-cost process, avoiding the need for application of coatings or use of abrasive as taught by the prior art. Preferably, such a luer fitting would be produced in a manner so as not to substantially alter the frictional fit of the luer fittings in comparison to conventional luer fittings.