Electrochemical system for disinfecting and cleaning contact lenses
The present invention is generally related to a lens care system and method for disinfecting and cleaning contact lenses. A lens care system or method of the invention is based on electrolysis of an aqueous chloride solution for generating germicide species (e.g., chlorine, hypochlorous acid, hypochlorite, or combinations thereof) and subsequent in-situ electrolysis of hypochlorous acid or hypochlorite in the aqueous solution for neutralizing the generated germicide species.
1. A lens care apparatus for disinfecting contact lenses, comprising:
(1) a container for holding an aqueous lens care solution, wherein the aqueous lens care solution has a pH of from about 6 to about 8 and comprises from about 0.5% to about 1.2% by weight of one or more chloride salts selected from the group consisting of sodium chloride, potassium chloride, and mixtures thereof, wherein the container comprises a container cup, a cap, and a lens holder, wherein the container cup is cylindrical and has a bottom panel and a tubular side wall defining an interior chamber accessible through an opening bounded by a circumferential upper rim opposite the bottom panel, wherein the container cup comprises first threads on the exterior surface of the container cup proximal to the upper rim, wherein the cap comprises a circular top panel and a circumferential collar extending transversely downward from the top panel, wherein the collar comprises second threads on the interior surface of the collar for engaging with the first threads on the container cup when the cap is screwed onto the container cup to close the container, wherein the lens holder comprises closable baskets and is attached to the interior surface of the top panel of the cap for inserting the lens holder into the container cup and for retaining the contact lenses immersed in the aqueous lens care solution in the container cup when the container is closed and is in use;
(2) a set of electrodes which are located in the interior chamber and on the bottom panel and immersed in the aqueous lens care solution when in use, wherein the set of electrodes comprises a first anode free of any negatively-charged membrane thereon, a second anode which is coated with a negatively charged membrane for preventing a negatively charged ion from accessing the second anode, a first cathode, and optionally a second cathode, wherein the second anode is a boron doped diamond electrode; and
(3) a control unit operatively connected to the set of electrodes and to a power source, wherein the control unit automatically applies a first potential between the first anode and the first cathode and drives an electrical current through the first anode and the first cathode for a first period of time to electrochemically generate germicide species which are chlorine, hypochlorous acid, hypochlorite, or combinations thereof for disinfecting the contact lenses, and after the first period of time and optionally a disinfecting period of time for disinfecting contact lenses with the electrochemically generated germicide species, automatically applies a second potential between the second anode and the first or second cathode and drives an electrical current through the second anode and the first or second cathode for a second period of time to electrochemically neutralize germicide species which are generated electrochemically but left-over from disinfecting of the contact lenses.
2. The lens care apparatus of claim 1 , wherein the set of electrodes comprises a second cathode.
3. The lens care apparatus of claim 2 , wherein the closable baskets open to receive the contact lenses to be disinfected and cleaned and close to retain the lenses during treatment.
4. The lens care apparatus of claim 3 , wherein the control unit comprises means for operatively connecting the electrodes with the power source and microprocessors/embedded systems for automatically controlling the polarity and potential of the electrodes, and the timing and duration of processes for electrochemically generating germicide species, for disinfecting contact lenses with the electrochemically generated germicide species, and for electrochemically neutralizing germicide species.
5. The lens care apparatus of claim 4 , wherein the control unit comprises a power pack, an automatic switching mechanism, or combinations thereof.
6. The lens care apparatus of claim 1 , wherein the closable baskets open to receive the contact lenses to be disinfected and cleaned and close to retain the lenses during treatment.
7. The lens care apparatus of claim 1 , wherein the control unit comprises means for operatively connecting the electrodes with the power source and microprocessors/embedded systems for automatically controlling the polarity and potential of the electrodes, and the timing and duration of processes for electrochemically generating germicide species, for disinfecting contact lenses with the electrochemically generated germicide species, and for electrochemically neutralizing germicide species.
8. The lens care apparatus of claim 7 , wherein the control unit comprises a power pack, an automatic switching mechanism, or combinations thereof.
9. The lens care apparatus of claim 8 , wherein the control unit comprises means for operatively connecting the electrodes with the power source and microprocessors/embedded systems for automatically controlling the polarity and potential of the electrodes, and the timing and duration of processes for electrochemically generating germicide species, for disinfecting contact lenses with the electrochemically generated germicide species, and for electrochemically neutralizing germicide species.
10. The lens care apparatus of claim 1 , wherein the control unit comprises a power pack, an automatic switching mechanism, or combinations thereof.