DRESSING COMPRISING ELECTRODES

Abstract

A dressing comprising first and second electrodes, an electrical power supply, and further comprising a physiologically or antimicrobially active precursor substance, the dressing being operable, when placed on a skin site to be treated, for a first treatment period, whereby the electrochemical oxidation or reduction of the precursor substance on one of the electrodes to produce a physiologically active oxidised or reduced substance which is capable of diffusing towards the skin site for the treatment thereof is carried out, and subsequently for a first rest period, the electrochemical oxidation or reduction is stopped, wherein subsequent treatment periods followed by rest periods are carried out over time.

Claims

1-5. (canceled)

6. A dressing, comprising: a body treatment portion comprising first and second electrodes and a physiologically or antimicrobially active precursor substance; and an electrical power supply; and wherein when placed on a skin site to be treated the dressing is operable: for a treatment period, to carry out electrochemical oxidation or reduction of the precursor substance on one of the electrodes to produce a physiologically active oxidised or reduced substance which is capable of diffusing towards the skin site for the treatment thereof; subsequently for a rest period, to stop the electrochemical oxidation or reduction; and to carry out subsequent treatment periods followed by subsequent rest periods over time; and wherein the treatment period and the rest period define a treatment cycle.

7. The dressing of claim 6, wherein the treatment cycle is at least 1 minute.

8. The dressing of claim 6, wherein the treatment cycle is at least 6 hours.

9. The dressing of claim 6, wherein the treatment cycle is from 6 to 36 hours.

10. The dressing of claim 9, wherein a ratio of a duration of the rest period to a duration of the treatment period is from 2:1 to 30:1.

11. The dressing of claim 6, wherein a ratio of a duration of the rest period to a duration of the treatment period is from 1:1 to 40:1.

12. A method of operating a dressing, wherein the dressing comprises an electrical power supply and a body treatment portion comprising first and second electrodes and a physiologically or antimicrobially active precursor substance, the method comprising: producing, for a treatment period, a physiologically active oxidised or reduced substance which is capable of diffusing towards a skin site for the treatment thereof by carrying out electrochemical oxidation or reduction of the precursor substance on one of the electrodes; and stopping, for a rest period, the electrochemical oxidation or reduction; and repeating the producing and the stopping over time; wherein the treatment period and the rest period define a treatment cycle.

13. The method of claim 12, wherein the treatment cycle is at least 1 minute.

14. The method of claim 12, wherein the treatment cycle is at least 6 hours.

15. The method of claim 12, wherein the treatment cycle is from 6 to 36 hours.

16. The method of claim 15, wherein a ratio of a duration of the rest period to a duration of the treatment period is from 2:1 to 30:1.

17. The method of claim 12, wherein a ratio of a duration of the rest period to a duration of the treatment period is from 1:1 to 40:1.

Description

[0045] The invention will now be illustrated, by way of example, and with reference to the following figures, in which:

[0046] FIG. 1 is an electrochemical dressing for use with the present invention.

[0047] FIGS. 2A and 2B are plan views showing detail of the electrodes of the treatment portion of the dressing shown in FIG. 1.

[0048] FIGS. 2C and 2D show side sectional views and exploded views respectively, of the line A-A through FIG. 6B.

[0049] FIG. 3 is a chart of measured current over time illustrating iodine levels.

[0050] FIG. 4 is a chart of measured current over time illustrating iodine levels.

[0051] Turning to the figures, FIG. 1 shows a dressing 10 according to the invention, the dressing being made up of a body treatment portion 12, a remote electrical power portion 14 and an electrical connecting portion 16.

[0052] The treatment portion comprises a number of planar electrodes 18 embedded in a cross-linked hydrogel 20. The electrodes meet a central electrode node 22. The body treatment portion 12 is attached to the electrical connecting portion 16 via the electrode node 22.

[0053] Electrical power portion has a receiving portion 24 for receiving the electrical connecting portion 16.

[0054] When it is desired to apply the dressing 10, the treatment portion is placed on the body surface requiring treatment. The electrical power portion 14 is connected to the electrical receiving portion by feeding it into receiving portion 24. An indicator light 26 lights up when an electrical circuit is formed with the treatment portion 12. The power portion is located, typically on the body, but remote from the treatment area.

[0055] Thus, the size and weight of the power portion 14 do not interfere with the functioning of the treatment portion 12.

[0056] FIGS. 2A and 2B shows again the detail of the electrode 18 placement in the treatment portion 12, and how they converge at the central electrode node 22.

[0057] FIGS. 2C and 2D show in detail how the treatment portion 12 is formed. Shown are releasable backing papers 40 and two hydrogel slabs 42. The electrodes 18 are made up of a PET film 44 onto which has been printed carbon electrically active surfaces 46, 48 forming the cathode and anode respectively.

[0058] It can be seen that the cathode and the anode have an electrically active side facing away from the other electrode and an electrically insulating side (the PET side) facing towards the other electrode to form the arrangement of the present invention.

[0059] In use, an electrical circuit is made when the power portion 14 is connected to the electrical connecting portion 16. The active precursor substance, e.g. chloride ions, are oxidised at the anode surface 48 to form hypochlorous acid HOCl. The HOCl migrates essentially normal to the surface 48 and therefore directly towards the body surface site 32. Surprisingly the HOCl does not mix with the cathodic reaction products formed on surface 46.

EXAMPLE

[0060] FIG. 3 is a trace of the iodine generation profiles detected in iodine-containing hydrogels subjected to the oxidising action of either the enzyme glucose oxidase or an electrode of the present invention. Deflection of the trace towards the bottom of the graph indicates an increase in iodine generation. The green line shows the over-production of iodine caused by glucose oxidase. The blue lines show the production of iodine by the electrodes at daily intervals over 5 days. The red sections of each electrode trace indicate the time during which the electrical pulse was applied.

[0061] FIG. 4 shows the iodine production pulses of FIG. 3, but superimposed on each other in order to make it easier to observe the consistency of iodine production on each of 5 consecutive daily pulses.

[0062] It can be seen how the pulsing achieves the necessary kill concentrations over several pulses which extends the lifetime of the dressing to several days, by conserving the supply of iodide over several pulses.