Iontophoretic device and method for killing bacteria and other microbes

• US 5,328,451 A
• Filed: 08/15/1991
• Issued: 07/12/1994
• Est. Priority Date: 08/15/1991
• Status: Expired due to Fees

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Davis, Charles P., Warren, Michael M.
• Primary Examiner(s): Cohen, Lee S.
• Application Number:
  US07/745,592
• Time in Patent Office: 1,062 Days
• Field of Search: 604/20, 604/21, 128/362, 422/22, 607/1, 607/2
• US Class Current: 604/20
• CPC Class Codes: A61N 1/306 Arrangements where at least part of the apparatus is introduced into the body

Abstract

An apparatus and method for killing microbes, including bacteria or yeast-like fungus within or on a conductive medium, is provided including positive and negative electrodes which may be activated to generate antimicrobial agents from within the conductive medium. The agents are any form of anions including atoms or molecules derived from inorganic salts present within the conductive medium. Due to residual killing effect caused by the presence of internally generated antimicrobial agents, constant activation of the electrodes is not necessary thereby allowing intermittent activation in order to prolong the life of the metallic or non-metallic electrodes. Electrode polarity can be reversed periodically to drive precipitation from the electrode surface and to also extend electrode life.

Claims

1. An apparatus for killing microbes in a conductive medium, comprising:

a positive and a negative electrode spaced apart from one another and placeable in a conductive medium, each postive and negative electrode being formed from an element including carbon;

an intermittent current source connected to said positive and negative electrodes; and

means for activating said source in periodic reverse polarity for generating antimicrobial agents from inorganic salts within said conductive medium.

2. The apparatus as recited in claim 1, wherein said positive and negative electrodes are spaced adjacent each other and are placed about the inside of a catheter.

3. The apparatus as recited in claim 1, wherein said activating means comprises an electrode polarity interchange circuit connected between said intermittent current source and said positive and negative electrodes.

4. The apparatus as recited in claim 3, wherein said electrode polarity interchange circuit comprises means for substantially reducing precipitation occurring between and upon said positive and negative electrodes.

19. The apparatus as recited in claim 1, wherein said positive and negative electrodes are spaced adjacent each other and are placed about the outside of a catheter.

20. The apparatus as recited in claim 1, wherein said positive electrode is wound about a first portion of the inside of a catheter and said negative electrode is wound about a second portion of the outside of said catheter, wherein said first portion is axially spaced from said second portion.

21. The apparatus as recited in claim 1, wherein said positive electrode is wound about a first portion of the outside of a catheter and said negative electrode is wound about a second portion of the outside of said catheter, wherein said first portion is axially spaced form said second portion.

26. The apparatus as recited in claim 1, wherein said positive and negative electrodes are spaced adjacent each other and are placed with a dressing.

5. A method for sterilizing a conductive medium, comprising:

placing positive and negative electrodes apart from each other and into said conductive medium, each postive and negative electrode being formed from an element including carbon;

connecting said positive and negative electrodes to an intermittent current source; and

activating said current source in periodic reverse polarity, whereby antimicrobial agents are released from inorganic salts contained within said conductive medium.

6. The method as recited in claim 5, wherein said connecting step comprises:

attaching said positive and negative electrodes to positive and negative poles, respectively, of said intermittent current source, for a first period of time; and

subsequently attaching said positive and negative electrodes to negative and positive poles, respectively, of said current source for a second period of time to prolong the useful life of said positive and negative electrodes and prevent precipitation accumulation on and between said electrodes.

7. The method of claim 5 wherein said conductive medium is a biological fluid.

8. The method of claim 7 wherein said conductive medium comprises blood.

9. The method of claim 7 wherein said conductive medium comprises urine.

10. The method of claim 7 wherein said conductive medium comprises tissue fluid.

11. The method of claim 5 further comprising, confining said conductive medium in a vessel.

12. The method of claim 11 wherein the vessel is physiological.

13. The method of claim 12 wherein the vessel is an internal organ.

14. The method of claim 12 wherein the vessel is an artery.

15. The method of claim 12 wherein the vessel is a vein.

22. The method of claim 5, wherein said conductive medium comprises a gas.

23. The method of claim 5, wherein said conductive medium comprises fluid from a water treatment plant.

16. A method for sterilizing a chlorine containing conductive medium, comprising:

placing positive and negative electrodes apart from each other and into said conductive medium, each positive and negative electrode being formed from an element including carbon;

connecting said positive and negative electrodes to an intermittent current source;

activating said current source in periodic reverse polarity;

releasing antimicrobial agents within said conductive medium; and

sterilizing said conductive medium by said antimicrobial agents.

17. The method as recited in claim 16, wherein said connecting step comprises:

attaching said positive and negative electrodes to positive and negative poles, respectively, of said intermittent current source, for a first period of time; and

subsequently attaching said positive and negative electrodes to negative and positive poles, respectively, of said current source for a second period of time to prolong the useful life of said positive and negative electrodes and prevent precipitation accumulation on and between said electrodes.

18. A method for sterilizing a conductive medium, comprising:

providing a halide containing conductive medium;

placing positive and negative electrodes apart from each other and into said conductive medium, each postive and negative electrode being formed from an element including carbon;

connecting said positive and negative electrodes to an intermittent current source; and

activating said current source in periodic reverse polarity;

releasing antimicrobial agents from said halide containing conductive medium; and

sterilizing said conductive medium by said antimicrobial agents.

24. The method of claim 18, wherein said halide comprises bromine.

25. The method of claim 18, wherein said halide comprises fluorine.