Filtering needle assembly with seal plug

A method for loading a quantity of a filtered liquid payload into a syringe and a connected hollow needle (150) and precluding loading a second quantity of filtered liquid payload into a second syringe connected to a second hollow needle, the method comprising:

• obtaining a reservoir of a liquid payload;
• attaching the syringe to a filtering needle assembly (100), the filtering needle assembly comprising:
• a needle and connector portion (110) and a filtering needle cap (200):
• the needle and connector portion (110) comprising:
• a hollow needle (150) with a distal tip (154) of the hollow needle having an opening to a lumen (156) running through the hollow needle;
• and
• a hub comprising:
• an open proximal end (114) adapted to reversibly engage a fluid fitting;
• and
• a distal end of the hub engaged with a proximal end of the hollow needle;
• and
• the filtering needle cap (200) comprising:
• a filtering needle cap body (250) with a distal open portion (204) in fluid communication via an internal channel with a proximal open end (208) of the filter needle cap body;
• and
• the proximal open end of the filter needle cap body sized to receive the distal end of the hub within the proximal open end of the filter needle cap body to reversibly engage the hub when the distal end of the hollow needle is inserted into the internal channel,
• a filter (400) adapted for removing debris from the liquid payload as the liquid payload is drawn through the filtering needle assembly into the lumen within the hollow needle as the liquid payload is drawn into the fluid fitting;
• and
• a seal plug (300) to surround the distal end of the hollow needle after the distal end of the hollow needle has been driven through the seal plug to form a seal between the seal plug and a distal portion of the hollow needle so that the liquid payload is drawn into the lumen in the hollow needle as the liquid payload is blocked by the seal plug from traveling down an outside diameter of the hollow needle within the filter needle cap body;
• the seal plug held in place by a holding tool (500) as the distal tip of the hollow needle is driven through the seal plug as the seal plug is able to move distally and away from the distal end of the hollow needle unless held in place by the holding tool so that the second hollow needle cannot be used to load the second quantity of the filtered liquid payload into the second syringe after removal of the hollow needle from the seal plug;
• using the syringe to draw in the liquid payload from the reservoir of the liquid payload, the liquid payload passing through the filter before entering the opening in the distal end of the hollow needle;
• and
• removing the hollow needle from the filtering needle assembly to expose the distal tip of the hollow needle.

A method of assembling a filtered needle assembly (100) comprising:

• obtaining:
• a needle and connector portion (110);
• a filtering needle cap body (250);
• a seal plug (300);
• and
• a filter (400);
• pushing the seal plug into an open distal end (204) of the filtering needle cap body (250) until the seal plug rests against an annular shoulder (220) at a distal end of a proximal chamber (212) that lies between the annular shoulder and an open proximal end (208) of the filtering needle cap body;
• holding the seal plug against the annular shoulder with a holding tool (500) that has an open midline while advancing a distal tip (154) of a hollow needle (150) through the seal plug so that the distal tip of the hollow needle extends beyond a distal end (304) of the seal plug and into the open midline of the holding tool;
• removing the holding tool after the distal tip of the hollow needle extends beyond the distal end of the seal plug;
• and
• inserting the filter into the distal end of the filtering needle cap body and securing the filter to the distal end of the filtering needle cap body.

A method for making a filtered needle assembly unable to work with a second hollow needle, the method comprising:

• loading a syringe with a liquid payload through the filtered needle assembly (100);
• removing a first distal tip (154) of a first hollow needle (150) attached to the syringe from an open proximal end (208) of the filtered needle assembly;
• subsequently, inserting a second distal tip (154) of the second hollow needle (150) into the open proximal end (208) of the filtering needle assembly;
• advancing the second distal tip of the second hollow needle through a proximal chamber (212) of the filtering needle assembly and into a hollow interior (316) of a seal plug (300);
• advancing the second distal tip of the second hollow needle distally until contact with the seal plug pushes the seal plug distally within a distal chamber (230) of the filtering needle assembly without the second distal tip traversing the seal plug;
• and
• failing to easily draw liquid into the second hollow needle as the second distal tip of the second hollow needle is not in the distal chamber as the second distal tip of the second hollow needle could not pass through the seal plug without a holding tool (500) holding the seal plug against an annular shoulder (220) at a distal end of the proximal chamber (212).