System with filter for administrating parenteral liquids

• US 3,978,857 A
• Filed: 02/03/1975
• Issued: 09/07/1976
• Est. Priority Date: 08/14/1972
• Status: Expired due to Term

• Current Assignee: General Electric Capital Corporation (General Electric Company)
• Original Assignee: American Hospital Supply Corp. (Baxter International Inc.)
• Inventors: McPhee, Charles J.
• Primary Examiner(s): Wyse, Thomas G.
• Assistant Examiner(s): Cintins, Ivars
• Application Number:
  US05/546,509
• Time in Patent Office: 582 Days
• Field of Search: 55/159, 128/214 R, 128/214 C, 128/214 D, 128/214.2, 128/218 R, 128/221, 210/23, 210/99, 210/435, 210/451, 210/455, 210/446, 210/479, 210/510, 210/DIG. 23
• US Class Current: 604/257
• CPC Class Codes: A61M 2005/1657 Filter with membrane, e.g. membrane, flat sheet type infusion filter
• CPC Class Codes: A61M 5/165 Filtering accessories, e.g. blood filters, filters for infusion liquids A61M1/14 , A61M1/34, A61M1/3627, A61M1/3679, A61M1/3687 take precedence; needle sets with incorporated air inlet filters A61M5/162

Abstract

A device for filtering a parenteral solution immediately before it is infused into a patient'"'"'s vein. The device has a hollow housing containing a "depth" filter membrane of nonfibrous hydrophobic material having randomly connected stacked passages of from 10 to 40 micron size through the filter. After the filter membrane has had one surface in contact with the parenteral solution for a period of 15 to 60 seconds while passing only a minute amount of liquid it is then manually tapped to send a shock wave through the filter. This shock wave unexpectedly causes the hydrophobic filter to freely pass liquid and filter out more than 90 percent of all particulate matter of 5 micron size and larger from the parenteral solution. The large pore hydrophobic filter membrane can perform these filtering efficiencies with a very small, thin disc-shaped membrane of approximately 1/4 inch effective diameter.

Claims

1. A combination for filtering parenteral solution comprising:

a parenteral solution bottle having means for suspending it above a patient, said bottle having a liquid outlet port;

an administration conduit connected to said outlet port for draining parenteral solution from said bottle, said administration conduit having a dispensing end;

a rigid thermoplastic transparent housing having a hollow chamber and a pair of tubular adapters communicating with this chamber and extending from opposite ends of the housing, one of said adapters being connected to the dispensing end of the administration conduit;

a pair of disc-shaped filter membranes fitting inside the hollow housing and permanently secured in face-to-face relationship to the hollow housing, said filter membranes each being of less than 0.375 inch diameter and each having a thickness of from 0.003 to 0.008 inch and having a "depth" of randomly interconnected stacked passages of from 20 to 30 micron size, said membrane being of a nonfibrous hydrophobic material and presenting a porous hydrophobic structure impervious to at least 95 percent of all particulate matter of 5 micron size and greater from parenteral solution in the bottle passing through the filter'"'"'s interconnected passages;

said housing including a plurality of support prongs having rounded generally hemispherical end contact surfaces abutting a central portion of one of said filter membranes to support it during liquid flow therethrough, said support prongs covering less than 20 percent of the effective filter area of the filter membranes; and

a hypodermic needle fitting over the other tubular adapter of the hollow housing.

2. A medical administration system that includes a container that has liquid therein and has an outlet connected to a depending tubular administration set for establishing a liquid head in the combined container and administration set for gravity dispensing liquid from a lower end of the administration set, wherein the improvement is:

a hollow housing with an inlet and an outlet, said housing connected in series with the administration set below the container outlet, and a "depth" filter membrane of hydrophobic non-fibrous material with randomly interconnected stacked passages of from 10 to 40 micron size, said filter membrane fitting inside the housing and permanently sealed to the housing between its inlet and outlet at a sealed joint adjacent a periphery of the filter membrane, said filter membrane providing a porous hydrophobic structure impervious to at least 90% of all particulate matter of 5 micron size and greater from a parenteral liquid passing through its interconnected passages; and

the housing has a plurality of support prongs having rounded generally hemispherical end contact surfaces engaging the filter membrane on its downstream side, said prongs blocking off less than 20% of the filter area bounded by the sealed joints, so that more than 80% of this filter area can pass liquid.

3. The combination as set forth in claim 2, wherein the hydrophobic filter membrane is of polytetrafluoroethylene.

4. The combination as set forth in claim 2 wherein the hydrophobic filter has interconnected passages of from 20 to 30 micron size.

5. The combination as set forth in claim 2, wherein the filter membrane is between 0.003 and 0.015 inch thick and has a diameter less than 0.375 inch, and the housing supporting this membrane is located adjacent a lower end of the administration set.

6. The combination as set forth in claim 2, wherein the filter membrane is comprised of a plurality of hydrophobic membrane layers of 0.003 to 0.008 inch thick, said membrane being impervious to 95 percent of all particulate matter of greater than 5 micron size.

7. The combination as set forth in claim 2, wherein the housing is formed of two hollow body members, a first body member telescopically fitting within a second body member and hermetically sealed together to seal the membrane within the housing, and the first hollow body member includes a hydraulic pressure surface and a wiper ring structure for hydraulically urging a bonding solvent through the passages of the filter membrane adjacent its periphery to permanently bond the membrane to the other hollow body member.

8. The combination as set forth in claim 7, wherein the hydraulic pressure surface includes a series of grooves for retaining a bonding solvent and a series of land surfaces for forcing solvent into passages of the membrane.