摘要 |
Medicinal fluid to be injected into a patient is drawn into a hypodermic syringe barrel through the valve portion of a combination valve and filter assembly, and is ejected through the filter, thereby preventing particulate contamination of the injected medicine. The valve and filter assembly comprises a generally cylindrical, porous filter element, and an elastomeric valve having a generally annular skirt portion overlying the distal end of the filter element and a central portion extending into the central passage in the filter. The central portion of the valve has a slit therein which opens to permit the flow of medicinal fluid therethrough in a distal-to-proximal direction, but closes to block the flow of fluid therethrough in a proximal-to-distal direction.
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