Perforate electrodiffusion pump

• US 6,409,698 B1
• Filed: 11/27/2000
• Issued: 06/25/2002
• Est. Priority Date: 11/27/2000
• Status: Expired due to Fees

• Current Assignee: John N. Robinson
• Original Assignee: John N. Robinson
• Inventors: Robinson, John N., Burke, Paul F., Fine, Kenneth A.
• Primary Examiner(s): WAYNER, WILLIAM E
• Application Number:
  US09/723,057
• Time in Patent Office: 575 Days
• Field of Search: 435/173.6, 604/20, 604/19, 604/501, 417/48, 220/455.0, 220/518
• US Class Current: 604/19
• CPC Class Codes: A61M 2005/14513 with secondary fluid driving or regulating the infusion
• CPC Class Codes: A61M 2205/3523 using telemetric means
• CPC Class Codes: A61M 2205/3569 sublocal, e.g. between console and disposable
• CPC Class Codes: A61M 31/002 Devices for releasing a drug at a continuous and controlled rate for a prolonged period of time artificial gland structures or devices A61F2/022; intra-uterine contraceptive devices A61F6/14; tampons for introducing into the vagina A61F13/20, A61L15/00; suppositories or bougies for intra-vaginal or intra-uterine application A61K9/02; physical forms of medicinal preparations for sustained or differential drug release A61K9/20, A61K9/50
• CPC Class Codes: A61M 39/0208 Subcutaneous access sites for injecting or removing fluids transcutaneous access sites A61M39/0247; implantable infusion devices A61M5/14276
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/172 electrical or electronic A61M5/16804, A61M5/16831 take precedence
• CPC Class Codes: A61N 1/30 Apparatus for iontophoresis, i.e. transfer of media in ionic state by an electromotoric force into the body, or cataphoresis

Abstract

An electrodiffusion pump includes a housing having an inlet, drug reservoir, and outlet. A diffusion membrane is disposed between the reservoir and outlet for diffusing the drug outwardly therethrough. Internal and external electrodes are disposed on opposite sides of the membrane. The electrodes are porous, and the external electrode is additionally perforate to expose a portion of the membrane at the outlet. The electrodes are electrically powered for driving drug ions through the membrane under electrophoresis to complement diffusion thereof.

Claims

1. An electrodiffusion pump for dispensing an ionic drug comprising:

a housing having an inlet for receiving said drug, a reservoir for storing said drug, and an outlet for discharging said drug;

a diffusion membrane disposed in flow communication between said reservoir and outlet for diffusing said drug outwardly therethrough;

an internal electrode disposed inside said reservoir along an internal side of said membrane;

an external electrode disposed outside said reservoir along an external side of said membrane;

said internal and external electrodes being porous for channeling said drug therethrough, and said external electrode further being perforate to expose a portion of said membrane at said outlet; and

means for electrically powering said electrodes as cathode and anode for additionally driving said ionic drug through said membrane under electrophoresis.

2. A pump according to claim 1 wherein:

said internal and external electrodes comprise mesh sheets disposed parallel to said membrane laterally across said internal and external sides thereof; and

said external electrode is perforate to include an external aperture facing outwardly from said membrane to expose said portion thereof, and said aperture is surrounded by smaller pores.

3. A pump according to claim 2 wherein said internal electrode is perforate to include an internal aperture facing inwardly from said membrane to match said external electrode.

4. A pump according to claim 3 wherein said internal and external electrodes each includes a single central aperture therein aligned with each other on opposite sides of said membrane.

5. A pump according to claim 3 wherein said internal and external electrodes each includes a plurality of apertures therein aligned with each other on opposite sides of said membrane.

6. A pump according to claim 5 wherein said outlet is circular, and said electrode apertures are arranged in a ring inside the perimeter of said outlet.

7. A pump according to claim 5 wherein said electrode apertures are rectangular and arranged in a rectangular grid.

8. A pump according to claim 7 wherein said internal and external electrodes include fibers crossing transversely to define said pores and rectangular apertures therebetween.

9. A pump according to claim 3 wherein said internal and external electrodes includes fibers crossing transversely to define said pores and apertures therebetween.

10. A pump according to claim 3 wherein said external electrode is spaced from said membrane to effect a gap therebetween.

11. A pump according to claim 3 wherein said external electrode is laminated to said membrane by an intervening electrical insulator being perforate to match said perforate external electrode.

12. A pump according to claim 11 wherein said insulator and external electrode have equal size apertures aligned therethrough.

13. A pump according to claim 11 wherein said insulator includes an aperture smaller than said aperture of said external electrode and aligned therewith.

14. A pump according to claim 11 wherein internal electrode is spaced from said membrane to effect a gap therebetween.

15. A pump according to claim 14 further comprising a remote electrode spaced inwardly from said internal electrode inside said reservoir, and electrically joined to said powering means to carry the same polarity as said internal electrode.

16. A pump according to claim 15 further comprising a plurality of ribs supporting said remote electrode above said internal electrode for permitting unobstructed flow of said drug therebetween inside said reservoir.

17. A pump according to claim 2 wherein said internal electrode is spaced inwardly from said membrane to effect a gap therebetween.

18. A pump according to claim 17 further comprising a plurality of ribs supporting said internal electrode above said membrane for permitting unobstructed flow of said drug therebetween inside said reservoir.

19. A pump according to claim 2 wherein said reservoir has a flexible boundary wall inside said housing for accommodating volume changes of said drug therein without pressurizing said membrane.

20. A pump according to claim 19 wherein said inlet includes an elastomeric plug for receiving a hypodermic needle 60 therethrough to fill said reservoir with said drug.

21. A pump according to claim 19 further comprising:

a tube joined in flow communication between said housing inlet and a remote inlet; and

said remote inlet includes an elastomeric plug for receiving a hypodermic needle therethrough to deliver said drug to said reservoir through said tube.

22. A pump according to claim 2 wherein:

said reservoir has a rigid boundary wall inside said housing with a fixed volume for said drug; and

said housing includes two of said inlets for simultaneously filling said reservoir with said drug through one inlet while removing a substantially equal amount of liquid from said reservoir through the other inlet.