摘要 |
Means to control the retraction of an auto-retractable safety syringe to minimise splashback or splatter is disclosed. The end of a hollow plunger ( 11 ) is covered by a sealing member ( 14 ) that, upon retraction, is dislodged so that the needle assembly and seal enters the hollow plunger. Three methods by which the auto-retraction is controlled are disclosed. Firstly there is provided a taper within the inside of the hollow plunger which creates varying resistance of movement to the sealing member. Secondly there is provided a bleed hole ( 15 ) at the upper end of the plunger, whereby the air is allowed to escape. Thirdly, there is provided on or more grooves ( 16 ) in the periphery of the plunger seal so that air is allowed to be released, thereby reducing the pressure in the plunger and hence the possibility of splashback.
|