Dialysis apparatus and technique

• US 4,496,458 A
• Filed: 07/09/1979
• Issued: 01/29/1985
• Est. Priority Date: 05/23/1977
• Status: Expired due to Term

• Current Assignee: McNeilab, Inc. (Johnson & Johnson)
• Original Assignee: Extracorporeal Medical Specialties Incorporated (Johnson & Johnson)
• Inventors: Lee, Kyu H.
• Primary Examiner(s): SPEAR JR, FRANK
• Application Number:
  US06/055,881
• Time in Patent Office: 2,031 Days
• Field of Search: 264/25, 156/73.1, 156/73.6, 156/159, 55/158, 210/22 A, 210/321 B, 210/450, 210/90
• US Class Current: 210/90
• CPC Class Codes: A61M 1/16 with membranes

Abstract

Dialysis apparatus is arranged to enable convenient measuring of ultrafiltration rate from liquid, such as blood, that is to be dialyzed. Dialyzer can have, downstream of a dialysis chamber, a dialyzate passageway through which the ultrafiltration flow rate can be readily measured as by introducing a gas bubble into the dialyzate and timing its movement through the passageway. An air-injection attachment can be fitted to the dialyzer or to a dialyzate supply system, to inject the gas bubble for such measurement. Bubble injection can also be effected in a flow rate measuring passageway downstream of the dialyzer. Flow rates of dialyzate into and out of dialyzer can be compared to show ultrafiltration while dialyzing. Dialyzer can also have end caps with thickned closure walls for better ultrasonic welding to the dialyzer body, and the caps can have vents that simplify testing of the seals between the caps and the dialysis membrane body.

Claims

1. An artificial kidney having a tubular casing and an end cap, the casing having an encircling flange to substantially the entire length of which the bottom edge of a skirt on the end cap is bonded, a ring-shaped gasket between the body of the end cap and an internal end wall near the end of the casing to enclose and seal in a chamber between cap body and wall, and a passageway through the cap at a location outside the sealed-in chamber.

2. The combination of claim 1 in which the passageway is a notch in the bottom edge of the skirt.

3. In the process of securing a short end-cap on the end of a tubular artificial kidney casing, the improvement according to which the casing has an outwardly extending encircling flange of fusible plastic near said end and an inwardly extending end wall, the cap is also of fusible plastic and has a body that closes the casing end as well as a skirt the bottom edge of which is notched and welded to the flange by applying a high-frequency vibrating member to the cap body while supporting the remote face of the flange and holding it against the skirt bottom, the notch remaining unwelded.

4. The combination of claim 3 in which a ring-shaped gasket is fitted between the cap body and the end wall to seal a chamber at the end of the casing, and the notch communicates with the outer aspect of the gasket ring.

5. An artificial kidney comprising a tubular casing having a first end, a second end, and an internal chamber;

a securing flange encircling, and extending outwardly from, said casing near one end thereof;

a bundle of hollow dialysis fibers in said internal chamber, said bundle of fibers having a first set of fiber ends and a second set of fiber ends,

the first set of fiber ends being potted in a potting resin which defines a first internal wall near the first end of the casing,

the second set of fiber ends being potted in a potting resin which defines a second internal wall near the second end of the casing, first and second end caps, said first end cap comprising a body portion and a skirt portion having an end edge;

first and second gaskets;

the end edge of the skirt portion of said first end cap being bonded to said securing flange and said first gasket being disposed in sealing relationship between said first internal end wall and said first end cap, whereby there is provided at the first end of said casing a first sealed end chamber in fluid communication with said first set of fiber ends, said first cap having a passageway therethrough at a location outside said first sealed-in chamber;

said second end cap being secured to said second end of said casing and said second gasket being disposed in sealing relationship between said second internal end wall and said second end cap, whereby there is provided at the second end of said casing a second sealed end chamber in fluid communication with said second set of fiber ends;

the lumens of said hollow fibers providing a path for the flow of blood between said first sealed end chamber and said second sealed end chamber;

said casing further comprising an inlet for liquids and an outlet for liquids, each said inlet and outlet being in fluid communication with the internal chamber of said casing and located between said first interior wall and said second interior wall, one of said two end caps further comprising means for introducing blood into the artificial kidney and the other of said two end caps further comprising means for withdrawing blood from the artificial kidney.

6. An artificial kidney according to claim 5 wherein said passageway is a notch in the bottom edge of said skirt.

7. An artificial kidney comprising a tubular casing having a first end, a second end, and an internal chamber;

first and second securing flanges,

said first flange encircling, and extending outwardly from, said casing near the first end thereof and said second flange encircling, and extending outwardly from, said casing near the second end thereof;

a bundle of hollow dialysis fibers in said internal chamber, said bundle of fibers having a first set of fiber ends and a second set of fibers ends,

the first set of fiber ends being potted in a potting resin which defines a first internal wall near the first end of the casing,

the second set of fiber ends being potted in a potting resin which defines a second internal wall near the second end of the casing,

first and second end caps, each of said end caps comprising a body portion and a skirt portion and each skirt portion having an end edge;

first and second gaskets;

the end edge of the skirt portion of said first end cap being bonded to said first securing flange and said first gasket being disposed in sealing relationship between said first internal end wall and said first end cap, whereby there is provided at the first end of said casing a first sealed end chamber in fluid communication with said first set of fiber ends, said first end cap further comprising means for introducing blood into said first sealed end chamber;

the end edge of the skirt portion of said second end cap being bonded to said second securing flange and said second gasket being disposed in sealing relationship between said second internal end wall and said second end cap, whereby there is provided at the second end of said casing a second sealed end chamber in fluid communication with said second set of fiber ends, said second end cap further comprising means for withdrawing blood from said second sealed end chamber;

one of said caps having a passageway therethrough at a location outside the sealed-in chamber associated with said one of said caps;

the lumens of said hollow fibers providing a path for the flow of blood between said first sealed end chamber and said second sealed end chamber;

said casing further comprising an inlet for liquids and an outlet for liquids, each said inlet and outlet being in fluid communication with the internal chamber of said casing and located between said first interior wall and said second interior wall.

8. An artificial kidney according to claim 7 wherein said passageway is a notch in the bottom edge of said skirt

9. A process for securing an end cap on an end of a tubular artificial kidney casing having an internal end wall and an outwardly extending encircling flange of fusible plastic near said end, said cap also being of fusible plastic and comprising a body and a skirt portion having an end edge, said cap also having a passageway therein, said process including the steps of:

placing said casing in a holder which engages the lower face of said flange;

placing a ring-shaped gasket against the outer face of said end wall.

placing said end cap in position over said flange so that the end edge of said skirt comes into contact with said flange;

bringing a high frequency vibrating member into engagement with said cap;

and actuating said high frequency vibrating member to secure the end edge of said skirt to said flange such that, after said securing process is completed, said passageway through said cap communicates with the outer aspect of said gasket.

10. A process according to claim 9 in which the body of said end cap has a thickness of from three to four millimeters.

11. A process according to claim 9 wherein said passageway is a notch in the bottom edge of said skirt.

12. A process according to claim 11 wherein said notch remains unwelded.