Pressure regulator for implantable pump

• US 5,067,943 A
• Filed: 09/26/1989
• Issued: 11/26/1991
• Est. Priority Date: 09/26/1989
• Status: Expired due to Term

• Current Assignee: Arrow Interventional, Inc. (Teleflex Incorporated)
• Original Assignee: InfusAID, Inc. (Pfizer Inc.)
• Inventors: Burke, Paul
• Primary Examiner(s): Rosenbaum, C. Fred
• Assistant Examiner(s): MCDERMOTT, CORRINE MARIE
• Application Number:
  US07/412,376
• Time in Patent Office: 791 Days
• Field of Search: 128/DIG. 12, 604/65-67, 604/93, 604/131, 604/140-141, 604/246-247, 604/890.1, 604/891.1
• US Class Current: 604/141
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/16881 Regulating valves on-off valves, e.g. clamps A61M39/28
• CPC Class Codes: Y10S 128/12 Pressure infusion

Abstract

An implantable pump system employing a flow regulator isolates the regulator sensing chamber from the path of drug flow. This is accomplished by establishing either an independent sensing chamber in the regulator or coupling it to the propellant chamber of the pump. Additionally, a downstream restrictor may be used to provide an additional pressure drop between the regulator and the outlet catheter.

Claims

1. An implantable drug delivery system comprising:

a pressure actuated drug dispensing device having a sealed body, said sealed body having a flexible drug reservoir containing a fluid, an outlet from said flexible drug reservoir and a propellant chamber in said sealed body pressurized to a pressure to urge said fluid from said flexible drug reservoir into said outlet, and

a flow regulating device having a regulator chamber and a sensing chamber, said regulator chamber and said sensing chamber separated and maintained in isolation from each other by a flexible diaphragm, said outlet supplying said fluid into said regulator chamber, an outlet catheter coupling said regulator chamber to a drug delivery site, a regulator seal in said regulating chamber of said flow regulating device, said regulator seal positioned relative to said diaphragm to vary the flow of fluid to said outlet catheter and, means not using said fluid to establish a reference pressure in said sensing chamber that is substantially equal to said pressure in said propellant chamber.

2. The system of claim 1 wherein said means to establish a reference pressure comprises a source of propellant in said sensing chamber that is the same as in the propellant chamber of said drug dispensing device.

3. The system of claim 1 further comprising a penetrable septum coupled to said drug reservoir for refilling said fluid.

4. The system of claim 1 further comprising a bacteria filter in said outlet and flow restrictor disposed in said outlet upstream of said regulator chamber.

5. The system of claim 1 wherein said flexible drug reservoir comprises a bellows disposed in said sealed body to define said drug reservoir.

6. The system of claim 1 wherein said flexible diaphragm is biased to deflect in the direction of said regulator seal.

7. An implantable drug delivery system comprising:

a sealed body having a flexible drug reservoir and a separate propellant chamber therein, a fluid in said drug reservoir, an outlet coupled to said drug reservoir, a flow regulating device physically coupled to said sealed body, said flow regulating device comprising a regulating chamber in fluid contact with said drug reservoir, a flexible diaphragm in said flow regulating device, a sensing chamber in said flow regulating device in fluid separation from said regulating chamber, means separate from said fluid in said drug reservoir to define a reference pressure in said sensing chamber substantially replicating the pressure in said propellant chamber such that said flexible diaphragm moves in response to variations in flow rate in said outlet to regulate the pressure in said regulating chamber, an outlet catheter coupled to said regulating chamber, and a regulator seal in said regulating chamber of said flow regulating device, said regulator seal positioned relative to said diaphragm to vary the flow of fluid to said outlet catheter.

8. The system of claim 7 wherein said means to establish a reference pressure comprises a source of propellant in said sensing chamber that is the same as in the propellant chamber of said drug dispensing device.

9. The system of claim 7 further comprising a penetrable septum coupled to said drug reservoir for refilling said fluid.

10. The system of claim 7 further comprising a bacteria filter in said outlet and flow restrictor disposed in said outlet upstream of said regulator chamber.

11. The system of claim 7 wherein said flexible drug reservoir comprises a bellows disposed in said sealed body to define said drug reservoir.

12. The system of claim 7 wherein said flexible diaphragm is biased to deflect in the direction of said regulator seal.