Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L2/00—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor
  • A61L2/24—Apparatus using programmed or automatic operation
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L12/00—Methods or apparatus for disinfecting or sterilising contact lenses; Accessories therefor
  • A61L12/02—Methods or apparatus for disinfecting or sterilising contact lenses; Accessories therefor using physical phenomena, e.g. electricity, ultrasonics or ultrafiltration
  • A61L12/023—Electrolysis
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L12/00—Methods or apparatus for disinfecting or sterilising contact lenses; Accessories therefor
  • A61L12/08—Methods or apparatus for disinfecting or sterilising contact lenses; Accessories therefor using chemical substances
  • A61L12/12—Non-macromolecular oxygen-containing compounds, e.g. hydrogen peroxide or ozone
  • A61L12/124—Hydrogen peroxide; Peroxy compounds
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L2/00—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor
  • A61L2/16—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor using chemical substances
  • A61L2/18—Liquid substances or solutions comprising solids or dissolved gases

Definitions

• an antiseptic solution typically one containing chemicals such as hydrogen peroxide although other disinfectants such as sorbic acid may also be used.
• the hydrogen peroxide solution is an eye irritant. Hence, any latent trace of the peroxide solution that remains on the lens surface or is absorbed into a porous lens is likely to cause the wearer extreme discomfort, if not pain. It is therefore necessary to remove or neutralize any residual peroxide in the con ⁇ tact lenses. Other chemical disinfectants are also irritating in varying degrees.
• a more effective solution to the neutralization problem has been found in the use of one or more catalysts to enhance the decomposition of a hydrogen peroxide solution.
• catalytic agents to accelerate the neutralization of a hydrogen peroxide solution absorbed by contact lenses in the course of sterilization is disclosed in U.S. Patent No. 3,912,451 to Gaglia, Jr. for a Method for Removing Hydrogen Peroxide from Soft Contact Lenses.
• Gaglia's method represents an improvement over some prior methods, specifically the ambient decomposition method, in that it substantially shortens the decomposition time, it still takes at least six (6) hours to reduce the percentage of peroxide to an acceptable level for contact lens wear.
• the instant invention overcomes the aforementioned problems of the prior art in substantially lessening the time for effective cleaning and sterilization of contact lenses and neutralization of the disinfectant solution through the use of electrolysis.
• the use of hydrogen peroxide and free radical electrolysis for sterilization in a contact lens disinfecting en ⁇ vironment according to the instant invention should not be confused with the use of electrolysis with ion current for sterilization of contact lenses per se without a disinfectant solution as disclosed in U.S. Patent No. 4,202,740 to Stoner et al. for Apparatus and Method for Disinfecting Objects.
• Electrolysis can also achieve disinfection by the generation • of certain free radicals such as H and 0 and pH changes when the electrolyte used in the solution is more stable than the water molecule and when the electrolyte itself generates additional free radicals that are not destructive to the material to be disinfected. Therefore in the electrolytic system of the instant invention the amount of H 202 can be reduced below the standard three percent (3%) used in solutions typical of the prior art. If the HO were completely removed from the electrolytic solution sterilization would still occur but would take a somewhat longer period of time. Without HO the disinfection rate can be increased with increased current.
• the generated free radicals and pH changes can, in addition to disinfection, be used to neutralize other agents such as cleaning enzymes and soaps added to the electrolyte.
• the instant invention provides an apparatus and method for disinfecting contact lenses, tonometers, plastic medical equipment and other poorly oxidizing objects by immersion in a solution with or without hydrogen peroxide, followed by subjecting the solution to electrolysis to rapidly decompose the hydrogen peroxide and at the same time generate free radicals so that together the effectiveness of the disinfection is increased and at the end of the process render the solution neutral so that it is compatible with the natural liquid se ⁇ cretions on the eye, thereby permitting the user to wear the lenses without undue delay.
• Another object of the invention is to provide an apparatus and method for disinfecting contact lenses, tonometers, plastic medical equipment and other poorly oxidizing objects without leaving any undesirable residue of chemical neutralizers or hydrogen peroxide on the lenses.
• Still another object of the invention is to provide an apparatus and method for disinfecting contact lenses, tonometers, plastic medical equipment and other poorly oxidizing objects wherein the lenses may be worn soon after they are sterilized without harm or discomfort caused by the disinfecting solution.
• An additional object of the invention is to provide an apparatus and method for disinfecting contact lenses, tonometers, plastic medical equipment and other poorly oxidizing objects which allows for a time period prior to electrolysis during which an enzyme or other chemical agent can clean the lenses and sterilization of the lenses and neutralization of the chemicals occurs thereafter.
• Another additional object of the invention is to provide an apparatus and method for disinfecting contact lenses, tonometers, plastic medical equipment and other poorly oxidizing objects with a pH sensitive enzyme followed by electrolysis to neutralize the enzyme.
• An additional further object of the invention is to provide an apparatus and method for generating free radical superoxides not only for disinfection of inanimate objects, but also for use on living tissue, e.g., cataracts.
• Fig. 1 is a perspective view of part of the apparatus of a preferred embodiment of the invention.
• Fig. 2(a) is an elevation view of the apparatus of Fig. 1 installed in an environment including additional apparatus of a preferred embodiment of the invention.
• Fig. 2(b) is a plan view of the apparatus of Fig. 2(a).
• Fig. 3 is a flow diagram for the method of a preferred embodiment of the invention.
• Fig. 4 is a schematic circuit diagram of part of the apparatus of a preferred embodiment of the invention.
• the lens case 1 can be made of nonconductive materials such as glass, most rigid or semi-rigid plas ⁇ tics, or any other material which is not significantly chemically reactive with hydrogen peroxide or free radicals generated in the disinfecting process.
• the lens case 1 is provided with circular covers 2 which can be threaded onto the the lens case 1 to seal the corresponding circular chambers 4 thereby preventing leakage of the solution 3.
• the solution 3 will be water containing from zero to three percent (0%-3%) hydrogen peroxide and a small amount, e.g.., 102 milimoles of sodium sulfate, Na 2SO4, or 153 milimoles of calcium sulfate,'
• Phosphate buffers e.g., NaH 2PO4,
• Na 2HPO4, or Na3PO4 may be added to maintain p ** H constant when necessary.
• Other phosphated buffers wherein metals from classes IA or IIA of the periodic table of elements are substituted for sodium can be used.
• small amounts of NaCl can be added to Na SO to cause generation of chlorine and hydroxides both of which are strong disinfectants.
• Metals from classes IA and IIA of the periodic table of the elements can be substituted for sodium in the various sodium containing salts herein.
• the salt is added in sufficient amounts to buffer the solution to a pH rendering it nearly isotonic with the tears secreted about the eyes.
• the major salt used should have the property of resistance to disintegration in the electrolytic system while small amounts of other salts such as NaCl and the water and hydrogen peroxide are broken down into free radicals.
• a pair of elongated thin wire electrodes including an anode 9 and a cathode 11. Electrically connected to the ends of the anode 9 and cathode 11, respectively, are a positive conductor 13 and a negative conductor 15.
• the electrodes 9 and 11 are preferably made of a metal alloy or other conducting material which is not readily oxidized, e.g. platinum, rhodium, iridium, carbon, platinum rhodium alloy or platinum iridium alloy.
• a metal alloy or other conducting material which is not readily oxidized, e.g. platinum, rhodium, iridium, carbon, platinum rhodium alloy or platinum iridium alloy.
• platinum rhodium, iridium, carbon, platinum rhodium alloy or platinum iridium alloy e.g. platinum, rhodium, iridium, carbon, platinum rhodium alloy or platinum iridium alloy.
• the size of the electrodes typically about 0.5mm diameter by 20mm length is such as to make the amount of electrode material much less than the cat ⁇ alytic amount needed for any material increase in the decomposition of the peroxide by catalytic action. Absent the electrolysis process taught herein, the insertion of the electrodes in the sterilizing solution would provide no material advantage over merely allowing the peroxide to normally decompose under ambient conditions.
• the lens case covers 2 are provided with openings 6 to permit oxygen to escape.
• an oxygen permeable liquid tight seal may be disposed within the openings in the covers 2 to further ensure against leakage of the disinfectant solution as will be known to those skilled in the art. Where no hydrogen peroxide is used and the disinfection period is kept short, the need for the openings 6 may be obviated.
• a source 17 of electrical potential which serves as- a power supply provides the energy for rapid decomposition of the sterilization solution 3.
• the source 17 may be A.C. or D.C.
• the source 17 is a conven ⁇ tional storage battery with a D.C. potential of between 1.5 and 20 volts, high enough to generate free radicals.
• a power source 17 capable of generating square waves having peaks of sufficient amplitude to generate free radicals is alternatively preferred.
• a timing and control unit 14 is provided for carrying out the lens cleaning, sterilization and disinfectant neutralization processes of the invention in accordance with the flow diagram of Fig. 3. The construction and operation of the timing and control unit is described with reference to Fig. 4.
• the timing and control unit 14 governs three process time periods.
• the lenses are placed in a salt solution as previously described which may contain cleaning agents, e.g. including one or more enzyme ingredients and/or soaps, and or an antiseptic, e.g., hydrogen peroxide.
• cleaning agents e.g. including one or more enzyme ingredients and/or soaps
• an antiseptic e.g., hydrogen peroxide.
• the cleaning agents, soaps or enzymes if present, remove contaminants from the lenses and the antiseptic, if present, kills infectious microorganisms.
• the electrolysis disinfects by pH changes as well as free radical formation and also neutralizes any residual hydrogen peroxide, and any enzymes or soaps added, thereby leaving a weak salt solution having a tonicity near the tonicity of the natural fluids surrounding the eyes.
• the first few seconds following the current interruption are included in the second period.
• the third time period follows the interruption of the electrolysis current following the disinfection of the lenses and neutralization of the solution 3. It is during the third time period that the cleaned, sterilized and neutralized lenses may be removed from the timing and control unit 14.
• a pair of electrodes 16 and 18 project upwardly from a planar mounting surface 20 on the timing and control unit 14 for contacting the conductors 13 and 15 respectively on the lens case 1. Electrode 18 is grounded while electrode 16 is normally maintained at the positive battery voltage to which it is connected through a resistor 20 which in the preferred embodiment of the invention has a resistance of approximately 1 megohm. When the electrodes 16 and 18 make contact with the conductors 13 and 15 which are bridged by the ion ⁇ ized solution 3, a current path is completed between the electrodes 16 and 18. Upon completion of the current path between the electrodes 16 and 18, the input to an inverter 22 is brought to ground potential.
• the low signal input to inverter 22 results in a high signal at the output of the inverter 22 which sets a flip-flop 24.
• the flip- flop 24 is a type 4013 CMOS.
• the resultant high signal at the Q output of flip-flop 24 feeds NAND gate 30.
• the other input of NAND gate 30 is connected to the output of an inverter 44.
• This signal is applied to an inverter buffer 32 and enables an eight bit counter 26, which can be a type 4520 CMOS integrated circuit, to begin counting pulses applied by a type 555 integrated circuit timer 28 which in the preferred embodiment of the invention generates one pulse approximately every ten seconds.
• Inverter 44 indicates the status of the eighth bit Q of the counter 26, i.e., whether the cleaning process is completed as will be later explained.
• the inverter buffer 32 which can be a 4049 CMOS integrated circuit, is connected to the anode of a red light emitting diode (L.E.D.) 34 having a cathode connected to ground through a resistor 35. This causes the L.E.D. 34 to light while the cleaning and, where an antiseptic such as hydrogen peroxide is used, partial disinfection of the lenses takes place.
• L.E.D. red light emitting diode
• the seventh bit Q 6 of the eight bit counter 26 goes high marking the completion of the cleaning portion of the process.
• the high output at the seventh bit of counter 26 sets a flip-flop 36 which can also be a type 4013 CMOS. This causes the Q output of flip-flop 36 to go low, and the output of an inverter buffer 38 which is connected to the base of transistor 40 to go high, thereby turning on transistor 40 to begin the generation of the free radicals as well as neutralizing the hydrogen peroxide (HO ) and/or any added soaps or enzymes.
• the electrolysis current should preferably be in the range of 2-120 milliamperes per cubic centimeter of solution.
• the total electrolysis current to generate the radicals in the solution 3 in both chambers 4 is approximately 10-600 milliamperes.
• the current flow also causes the peroxide, if any is present, to be reduced to water and free oxygen in ac ⁇ cordance with the following relationship.
• the high signal at the Q output of flip-flop 36 turns off transistor 40 thereby halting the electrolysis current flow.
• the output of the eighth bit of the counter 26 is connected to the inverter buffer 44, which can be a 4049 CMOS integrated circuit.
• Inverter buffer 44 is connected to inverter buffer 61 which is, in turn, connected to the anode of a green light emitting diode (L.E.D.) 46 having a cathode connected to ground through a resistor 45. This causes the green L.E.D. 46 to light after the sterilization by radicals with or without peroxide and the neutralization by electrolysis of the solution 3 has been completed, thereby signaling the user to remove the lens case 1 from the timing and control unit 14.
• L.E.D. green light emitting diode
• the cleaned, sterilized and neutralized lenses can then be removed .from the lens case 1 and safely inserted into the eyes. Removal of the lens case 1 causes the flip-flops 24 and 36 to be reset at which time the counter 26 is initialized and the L.E.D.s 34 and 46 are turned off.
• the timing and control unit 14 is automatically initialized either when the lens case 1 is removed from the timing and control unit 14 or system battery power is removed and then reapplied.
• the reset logic for initializing the system is provided by NAND gates 48 and 50.
• a NAND gate 42 has its respective inputs connected to the output Q of flip-flop 36 and to the electrode 16 for generating a low output signal when the transistor 40 is off and the case 1 is out of the timing and control unit 14. Capacitor 56 and diode 58 prevent sudden changes in the voltage at the input of NAND gate 42 which could upset the sequence for reinitializing the system.
• NAND gate 48 has its other input connected to capacitor 54 and resistor 60. When power is reapplied after being off, the capacitor 54 is charged through resistor 60 and provides a low signal pulse. The low signal pulse is applied to the other input of NAND gate 48. This low signal pulse causes a reset signal to be generated whenever power is restored after being interrupted.
• Operational amplifier 31 has its respective inputs connected to the electrode 16 and to a voltage divider formed by resistors 63 and 64.
• the values of the resistors 63 and 64 are such that the voltage at the node between them is lower than the voltage at elec ⁇ trode 16 when transistor 40 is on and the case 1 is out of the timing and control unit 14 and higher than the voltage at electrode 16 during any other condition, i.e., the operational amplifier 31 yields a low logic output when transistor 40 is on and the case 1 is taken out of the timing and control unit 14.
• NAND gate 50 has its respective inputs connected to the output of inverter 62 and to the output of operational amplifier 31.
• a high signal output from NAND gate 50 is used to reset counter 26 and flip-flops 24 and 36 when the case 1 is removed from the timing and control unit 14 while transistor 40 is off, or the case 1 is removed from the timing and control unit 14 while transistor 40 is on, or power is restored after being interrupted.
• the reset signal from the output of NAND gate 50 is applied to the reset inputs of flip-flops 24 and 36 and turns off the red L.E.D. 34 and 46 if either was previously lit.
• the container 1 is partially filled with a sterilizing solution of water (HO), hydrogen peroxide (HO ) and salt (Na S04, CaSO , NaBr, KBr, Nal, KI, phosphate buffer or other organic salts that ionize but are otherwise stable at the applied potential) in the above stated relative quantities.
• HO water
• HO hydrogen peroxide
• salt Na S04, CaSO , NaBr, KBr, Nal, KI, phosphate buffer or other organic salts that ionize but are otherwise stable at the applied potential
• the resultant solution is a dilute saline having a tonicity and pH like that of the tears.
• Ultrasonic cleaners may be used in conjunction with the apparatus of the invention. It is to be appreciated that the foregoing is a description of a preferred embodiment of the invention to which variations and modifications may be made without departing from the spirit and scope of the invention.
• the invention is not limited to sterilizing contact lenses and may apply to the disinfection of any article or object which can be cleaned and sterilized by electrolysis. Additionally, the apparatus and method can be used for the treatment of diseased tissue.
• free radical containing solution is believed to be able to destroy or, at least, retard the growth of infectious viruses and bacteria in living tissue.
• the apparatus herein described can be used for tissue treatment. It can also be used in the experimental evaluation of the destructive effects of superoxides on the heart muscle and cataracts. In vitro studies can be done using the apparatus to generate free radicals, such as superoxides, in solutions, inserting the tissue into the solution, and observing the effects of the free radicals, e.g., superoxides, on the tissue.

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• 1988
  • 1988-07-13 JP JP63506831A patent/JPH03502050A/ja active Pending
  • 1988-07-13 EP EP19880906780 patent/EP0376962A4/en not_active Withdrawn
  • 1988-07-13 WO PCT/US1988/002376 patent/WO1989000430A1/en not_active Application Discontinuation
  • 1988-07-13 BR BR888807619A patent/BR8807619A/pt not_active Application Discontinuation
  • 1988-07-15 MX MX012276A patent/MX173044B/es unknown
  • 1988-07-15 ES ES888802240A patent/ES2010292A6/es not_active Expired
  • 1988-07-15 IL IL87127A patent/IL87127A/xx unknown
  • 1988-07-15 NZ NZ225423A patent/NZ225423A/en unknown
• 1990
  • 1990-01-15 FI FI900213A patent/FI900213A0/fi not_active Application Discontinuation
  • 1990-01-17 DK DK013590A patent/DK13590A/da not_active Application Discontinuation
• 1992
  • 1992-03-30 AU AU13901/92A patent/AU1390192A/en not_active Abandoned

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