Piercing needle having hydrophobic filter vent

• US 5,242,411 A
• Filed: 01/15/1992
• Issued: 09/07/1993
• Est. Priority Date: 01/18/1991
• Status: Expired due to Term

• Current Assignee: Terumo Kabushiki Kaisha (Terumo Corporation)
• Original Assignee: Terumo Kabushiki Kaisha (Terumo Corporation)
• Inventors: Yamamoto, Masanobu, Hayashi, Kouhei
• Primary Examiner(s): Wilson, John J.
• Assistant Examiner(s): Smith, Jeffrey A.
• Application Number:
  US07/821,426
• Time in Patent Office: 601 Days
• Field of Search: 604/168, 604/126, 604/264, 604/164, 604/167, 604/93
• US Class Current: 604/167.04
• CPC Class Codes: A61M 25/0606 "Over-the-needle" catheter assemblies, e.g. I.V. catheters
• CPC Class Codes: A61M 25/0693 Flashback chambers

Abstract

A piercing needle with which a flashback can be reliably confirmed and air can be prevented from remaining in its hub portion. The piercing needle comprises an outer needle having a hub, an inner needle to be inserted into the outer needle, a hub portion of which is adapted to be fitted in the outer needle hub, and a valve disc to close the internal cavity of the outer needle. Side holes are formed in the distal end of the outer needle. The outer needle hub is provided with a hydrophobic vent filter near the valve disc to allow the internal cavity of the outer needle hub to communicate with the outer atmosphere.

Claims

1. A piercing needle comprising:

a cylindrical outer needle;

an outer needle hub fixed to a proximal end of said outer needle, said outer needle hub having an internal cavity which communicates with said outer needle;

an inner needle, freely insertable into and removable from said outer needle through said outer needle hub, said inner needle being insertable into said outer needle such that a needle tip of said inner needle projects from a distal end of said outer needle;

an inner needle hub fixed to a proximal end of said inner needle, said inner needle hub fitting into said outer needle hub; and

a valve disc that is extended to close said internal cavity of said outer needle hub;

a rod member insertable through said valve disc; and

wherein;

a plurality of side holes are formed in a distal end portion of said outer needle to allow said internal cavity of said outer needle hub to be in fluid communication with an outer atmospheric pressure through said side holes even when said outer and inner needles are assembled together;

said outer needle hub includes a plurality of air vent holes which allow said internal cavity of said outer needle to be in fluid communication with said outer atmospheric pressure, and a vent hydrophobic filter interposed between a plurality of internal cavity-side end portions of said air vent holes and said valve disc; and

said valve disc includes a disk portion having cut portions therein, such that when said rod member is inserted in said valve disc through said cut portions, a central portion of said valve disc is moved away from a center axis of said valve disc in a forward insertion direction of said rod so that the moved away central portion of said valve disc covers an inner circumferential surface of said vent filter.

2. A needle according to claim 1, wherein said vent filter is ring shaped.

3. A piercing needle comprising:

a cylindrical outer needle;

an outer needle hub fixed to a proximal end of said outer needle, said outer needle hub having an internal cavity that is in fluid communication with said outer needle;

an inner needle, freely insertable into and removable from said outer needle through said outer needle hub, said inner needle being insertable into said outer needle such that a needle tip of said inner needle projects from a distal end of said outer needle;

an inner needle hub fixed to a proximal end of said inner needle, said inner needle hub fitting into said outer needle hub;

a valve member that is extended to close said internal cavity of said outer needle hub;

a rod member insertable through said valve member;

a vent filter positioned at an inner surface of, and adjacent to, said valve member to allow said internal cavity of said outer needle hub to be in fluid communication with an outer atmospheric pressure; and

said outer needle hub includes a projected portion on an outer circumferential surface thereof, said projected portion having a plurality of air vent holes formed in side surfaces thereof for providing a fluid communication path to said internal cavity of said outer needle hub via said vent filter.

4. A piercing needle according to claim 3, wherein said vent filter is ring shaped.

5. A piercing needle comprising:

a cylindrical outer needle;

an outer needle hub fixed to a proximal end of said outer needle, said outer needle hub having an internal cavity that is in fluid communication with said outer needle;

an inner needle, freely insertable into and removable from said outer needle through said outer needle hub, said inner needle being insertable into said outer needle such that a needle tip of said inner needle projects from a distal end of said outer needle;

an inner needle hub fixed to a proximal end of said inner needle, said inner needle hub fitting into said outer needle hub;

a valve member that is extended to close said internal cavity of said outer needle hub;

a rod member insertable through said valve member;

a hydrophobic vent filter provided at an inner surface of, and adjacent to, said valve member to provide said internal cavity of said outer needle hub with a fluid communication path to an outer atmospheric pressure; and

a projected portion formed on an outer circumferential surface of said outer needle hub, said projected portion having a plurality of air vent holes formed in a side surface thereof for providing a fluid communication path to said internal cavity of said outer needle hub via said vent filter.

6. A needle according to claim 5, wherein said vent filter is ring shaped.

7. A piercing needle comprising:

a cylindrical outer needle;

an outer needle hub fixed to a proximal end of said outer needle, said outer needle hub having an internal cavity that is in fluid communication with said outer needle;

an inner needle, freely insertable into and removable from said outer needle through said outer needle hub, said inner needle being insertable into said outer needle such that a needle tip of said inner needle projects from a distal end of said outer needle;

an inner needle hub fixed to a proximal end of said inner needle, said inner needle hub fitting into said outer needle hub;

a valve member that is extended to close said internal cavity of said outer needle hub;

a rod member insertable through said valve member;

a plurality of air vent holes formed in said outer needle hub, said plurality of air vent holes allowing said internal cavity of said outer needle hub to be in fluid communication with an outer atmospheric pressure;

a vent filter interposed between a plurality of internal cavity-side end portions of said plurality of air vent holes and said valve member; and

a disk portion of said valve member having cut portions;

wherein when;

said rod member is inserted in said valve member through said cut portions of said disc portion, a central portion of said valve member is moved away from a center axis of said valve member in a forward insertion direction of said rod member away from said rod member so that the moved away portion of said valve member covers an inner circumferential surface of said vent filter.

8. A needle according to claim 7, wherein said vent filter is ring shaped.

9. A needle according to claim 7, wherein said vent filter is hydrophobic.