System and method for attaching upper and lower outer cases in an implantable drug pump

• US 6,719,739 B2
• Filed: 08/27/2001
• Issued: 04/13/2004
• Est. Priority Date: 08/30/2000
• Status: Expired due to Fees

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Verbeek, Maurice T. Y., Philippens, Frans
• Primary Examiner(s): Thanh, LoAn H.
• Application Number:
  US09/940,344
• Publication Number:
  US 20020072721A1
• Time in Patent Office: 960 Days
• Field of Search: 604/131, 604/132, 604/140, 604/146, 604/151, 604/207, 604/890--89, 604/500, 604/48, 604/93.01, 604/288-1-2, 264/248, 264/345-346, 294/28--29
• US Class Current: 604/288.04
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

An implantable pump having a bulkhead, a reservoir structure attached to the bulkhead and upper and lower cases attached to the bulkhead by a single outer seal as well as a method of making such a pump is disclosed. The reservoir structure forms a reservoir that contains fluid drug or other medicaments. The upper and lower cases are attached to the bulkhead by first connecting either the upper or lower case directly to the bulkhead. Then, the lower or upper case not attached to the bulkhead is attached to the upper or lower case that had been previously attached to the bulkhead.

Claims

1. A method of assembling an implantable infusion pump having a reservoir for storing fluid, an outlet port, a metering system for metering fluid in the reservoir to the outlet port, a bulkhead for positioning the reservoir and metering system, the bulkhead having an outer periphery;

a first case having a bottom surface and a first case side wall, the first case side wall terminating in a first case terminal end, the first case having a thickness; and

a second case having a top surface and an second case side wall, the second case side wall having an inner surface and an outer surface, the second case side wall terminating in an second case terminal end and having an ultimate end near the second case terminal end, the second case having a thickness, the method connecting the second case to the bulkhead and the first case to the second case and comprising the steps of;

forming an inward bend in the second case side wall to form a displaced end portion substantially parallel, although inwardly displaced, to the second case side wall opposite the inward bend, the amount of displacement of the displaced end portion being about equal to the thickness of the first case;

locating and connecting the second case terminal end to the bulkhead whereby the inner surface of the second case side wall near the second case terminal end is in contact with the bulkhead, the step of locating and connecting the second case terminal end to the bulkhead including welding the second case terminal end to the bulkhead; and

locating and sealingly connecting the first case terminal end to the outside surface of the displaced end portion whereby the first case is connected to the second case, the step of locating and sealingly connecting the first case terminal end to the outside surface of the displaced end portion including welding the first case terminal end to the second case side wall.

2. The method of claim 1 further comprising forming an annular recess in the outer periphery of the bulkhead extending around the outer periphery;

the step of locating and sealingly connecting the second case terminal end to the bulkhead including placing the displaced end portion of the second case in the annular recess.

3. The method of claim 2 in which the step of locating and sealingly connecting the second case terminal end to the bulkhead includes forming a second space adjacent the first case terminal end within the recess, the step of welding the second case terminal end to the bulkhead including placing a second weld within the second space.

4. The method of claim 1 further comprising forming an annular recess in the outer periphery of the bulkhead extending around the outer periphery;

the step of locating and sealingly connecting the second case terminal end to the bulkhead including placing the displaced end portion of the second case in the annular recess.

5. The method of claim 4 in which the step of locating and sealingly connecting the second case terminal end to the bulkhead includes forming a second space adjacent the first case terminal end within the recess, the step of welding the second case terminal end to the bulkhead including placing a second weld within the second space.

6. The method of claim 1 in which the reservoir comprises an expandable and contractable bellows structure, the method further comprising sealingly connecting the bellows structure to the bulkhead.

7. The method of claim 6 in which the step of sealingly connecting the bellows structure to the bulkhead comprises welding the bellows structure to the bulkhead.

8. The method of claim 1 in which the step of locating and sealingly connecting the first case terminal end to the outside surface of the displaced end portion includes forming a first space between the second case terminal end and the inward bend, the step of welding the second case terminal end to the bulkhead including placing a first weld within the first space.

9. The method of claim 1 in which the step of locating and sealingly connecting the first case terminal end to the outside surface of the displaced end portion forms a single outer seal.

10. The method of claim 1 in which the first case comprises a lower case, and the second case comprises an upper case.

11. The method of claim 1 in which the first case comprises an upper case and the second case comprises a lower case.

12. A method of assembling an implantable infusion pump having a reservoir for storing fluid, an outlet port, a metering system for metering fluid in the reservoir to the outlet port, a bulkhead for positioning the reservoir and metering system, the bulkhead having an outer periphery with an upper edge, a lower case having a bottom surface and a lower case side wall, the lower case side wall terminating in a lower case terminal end, the lower case having a thickness and an upper case having a top surface and an upper case side wall, the upper case side wall having an inner surface and an outer surface, the upper case side wall terminating in an upper case terminal end and having an ultimate end near the upper case terminal end, the method connecting the upper case to the bulkhead and the lower case to the upper case and comprising the steps of:

forming an annular recess in the outer periphery extending around the outer periphery at the upper edge at the periphery, the recess having a recess bottom and a vertical wall connecting the recess bottom to the upper edge, the recess bottom having a width about equal to the thickness of the upper case;

forming an inward bend in the upper case side wall so that the ultimate end is substantially parallel, although inwardly displaced, to the upper case side wall opposite the inward bend, the amount of displacement of the upper case terminal end being about equal to the thickness of the lower case, the upper case having a thickness; and

locating and connecting the upper case terminal end to the recess bottom whereby the inner surface of the upper case side wall near the upper case terminal end is in contact with the vertical wall, the step of locating and connecting the upper case terminal end to the recess bottom including welding the upper case terminal end to the recess bottom;

locating and connecting the lower case terminal end to the outside surface of the upper case side wall near the inward bend whereby, the lower case is connected to the upper case, the step of locating and connecting the lower case terminal end to the outside surface of the upper case side wall near the inward bend including welding the lower case terminal end to the outside surface of the upper case side wall.

13. An implantable infusion pump comprising;

a reservoir for storing fluid;

an outlet port;

a metering system for metering fluid in the reservoir to the outlet port;

a lower case having an bottom surface and a lower case side wall, the lower case side wall terminating in a lower case terminal end, the lower case having a thickness;

an upper case having a top surface and an upper case side wall, the upper case side wall having an inner surface and an outer surface, the upper case side wall terminating in an upper case terminal end and having an ultimate end near the upper case terminal end, the upper case side wall having an inward bend formed so that the ultimate end is substantially parallel, although inwardly displaced, to the upper case side wall opposite the inward bend, the amount of displacement of the upper case terminal end being about equal to the thickness of the lower case, the upper case having a thickness; and

a bulkhead for positioning the reservoir and metering system, the bulkhead having an outer periphery with an upper edge, the outer periphery having an annular recess extending around the outer periphery at the upper edge at the periphery, the recess having a recess bottom and a vertical wall connecting the recess bottom to the upper edge, the recess bottom having a width about equal to the thickness of the upper case;

wherein, the upper case terminal end is located approximately at and connected to the recess bottom whereby the inner surface of the upper case side wall near the upper case terminal end is in contact with the vertical wall;

wherein, the lower case terminal end is located on and connected to the outside surface of the upper case side wall near the inward bend whereby, the lower case is connected to the upper case; and

wherein the upper case terminal end is welded to the recess bottom and the lower case terminal end is welded to the outside surface of the upper case side wall.

14. An implantable infusion pump having a reservoir for storing fluid, an outlet port, a metering system for metering fluid in the reservoir to the outlet port, a bulkhead for positioning the reservoir and metering system, the bulkhead having an outer periphery with an upper edge, a lower case having a bottom surface and a lower case side wall, the lower case side wall terminating in a lower case terminal end, the lower case having a thickness and an upper case having a top surface and an upper case side wall, the upper case side wall having an inner surface and an outer surface, the upper case side wall terminating in an upper case terminal end and having an ultimate end near the upper case terminal end, wherein the improvement comprises:

the outer periphery having an annular recess extending around the outer periphery at the upper edge at the periphery, the recess having a recess bottom and a vertical wall connecting the recess bottom to the upper edge, the recess having a width about equal to the thickness of the upper case;

the upper case side wall having an inward bend formed so that the ultimate end is substantially parallel, although inwardly displaced, to the upper case side wall opposite the inward bend, the amount of displacement of the upper case terminal end being about equal to the thickness of the lower case, the upper case having a thickness; and

wherein, the upper case terminal end is located approximately at and connected to the recess bottom whereby the inner surface of the upper case side wall near the upper case terminal end is in contact with the vertical wall;

wherein, the lower case terminal end is located on and connected to the outside surface of the upper case side wall near the inward bend whereby, the lower case is connected to the upper case; and

wherein the upper case terminal end is welded to the recess bottom and the lower case terminal end is welded to the outside surface of the upper case side wall.