Syringe tip cap with self-sealing filter
First Claim
Patent Images
1. A cap for facilitating purging of gases from a syringe containing hazardous liquids and the gases, comprising:
- a tubular housing which contains(a) first and second opposing ends, wherein said first end is open,(b) connecting means at said first end of said housing which can form an airtight fit with an open end of the syringe, and(c) filter means, consisting essentially of a hydrophilic filter sufficiently thick to prevent liquid from flowing out from said housing, fixed in said housing between said first and second opposing ends.
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Accused Products
Abstract
A syringe tip cap and a method for purging air from a syringe-like container containing air and hazardous liquid. The cap contains a hydrophilic filter which, when dry, allows air to pass through the filter. When the air is purged from the syringe, liquid from the container is pushed or drawn to the filter. The filter expands when wetted, seals the cap, and prevents further fluid flow. A flow restrictor may be included within the cap to concentrate the flow to only a portion of the filter to prevent premature sealing of the filter.
162 Citations
24 Claims
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1. A cap for facilitating purging of gases from a syringe containing hazardous liquids and the gases, comprising:
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a tubular housing which contains (a) first and second opposing ends, wherein said first end is open, (b) connecting means at said first end of said housing which can form an airtight fit with an open end of the syringe, and (c) filter means, consisting essentially of a hydrophilic filter sufficiently thick to prevent liquid from flowing out from said housing, fixed in said housing between said first and second opposing ends. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A capped syringe comprising:
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a syringe tube having a concentrically narrowed outlet end; a plunger reciprocally slidable within said syringe tube; a cap housing having an open end for receiving the narrowed end of said syringe tube in an airtight fit, an other end with a vent hole and a passageway between the open end and the other end; and a filter means, consisting essentially of a hydrophilic filter, said filter means secured within said cap housing, having a cross-section which covers the passageway and being sufficiently thick to prevent liquid flow from the open end to said vent hole. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A filtered syringe cap comprising:
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a housing having a vent hole at one end, means for receiving a syringe tip in an airtight fit at an other end and a hollow cavity between said ends; a hydrophilic filter secured within said housing so as to cover said vent hole, said filter having a face exposed to said hollow cavity; and means for defining an opening in said other end of said housing such that fluid expelled through said opening and into said hollow cavity is directly aligned with only a portion of the exposed face of said hydrophilic filter; said hollow cavity extending so as to form a reservoir within said housing surrounding said means for defining an opening, said reservoir configured so as to hold liquid components of the fluid away from the exposed face of said filter after the fluid has been expelled from a syringe through said opening so that portions of said filter remain dry to allow gas components of the fluid to escape until said hollow cavity is filled with the liquid components. - View Dependent Claims (17, 18, 19)
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20. A method for purging gases from an arterial blood gas sample, comprising the steps of:
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providing a syringe containing an arterial blood gas sample; removing a needle from a luer end of said syringe; attaching a vented cap, bearing a hydrophilic filter within the vent, over the luer end of said syringe; holding said capped syringe with its capped end above its plunger; and advancing the plunger within said syringe to expel gas and blood from the luer end of said syringe until the blood causes said filter to become sealed, such that the gas escapes through said filter and the blood is prevented from escaping by said filter.
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21. A filtered syringe cap comprising:
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a housing having an open end for receiving a syringe in an airtight fit, an other end with a vent hole and a passageway between the open end and the other end; a hydrophilic filter secured within said housing and having a cross section which covers the passageway so as to prevent liquid flow the open end to said vent hole; and means, interposed between the open end and said hydrophilic filter, for restricting the flow of fluid from said syringe tip. - View Dependent Claims (22, 23, 24)
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Specification