Hydrogel processing
OwnerJonathan Adams, Paul Lisenby +1inventors
InventorsJonathan Adams, Paul Lisenby, David Turner
Life of this patent
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Abstract
Disclosed are methods and apparatus for hydrating ophthalmic lenses and leaching excess materials from the ophthalmic lenses. The methods include the steps of exposing contact lenses with a hydration solution comprising about 30 to 70 percent isopropyl alcohol and water. In some embodiments, the hydration solution is maintained at an elevated temperature. Exposure to a first hydration solution causes the ophthalmic lenses to swell to a size larger than their functional size, and exposure to a second ophthalmic solution causes the lenses to shrink back to a functional size.
Claims30
A method of processing an ophthalmic lens comprising silicone hydrogel, the method comprising:
- depositing a lens forming resin in a mold part;
- curing the lens forming resin to form an ophthalmic lens and cause the ophthalmic lens to adhere to the mold part;
- heating a first hydration solution of about 30% to 70% IPA to a temperature of between about 30° C. and about 72° C.;
- exposing the ophthalmic lens to the heated first hydration solution of about 30% to about 70% isopropyl alcohol for a first time period of between about 10 and about 60 minutes causing the ophthalmic lens to release from the mold part;
- heating a second hydration solution of about 30% to about 70% IPA to a temperature of between about 30° C. and about 72° C.;
- exposing the ophthalmic lens to the heated second hydration solution of about 30% to about 72% IPA for a second period of about 10 minutes to about 60 minutes leaching unreacted components and diluents from the ophthalmic lens;
- and
- exposing the lens to a third hydration solution comprising about 100% deionized water for a third time period of about 10 minutes to about 180 minutes rinsing the second hydration solution from the lens.
A method of processing an ophthalmic lens comprising silicone hydrogel, the method comprising:
- depositing a lens forming resin on a lens forming surface of a first mold part;
- bringing the lens forming mixture into contact with a second lens forming surface of a second mold part, wherein the first mold part and the second mold part are configured to receive each other such that a cavity is formed between the first lens forming surface and the second lens forming surface and wherein the cavity defines the shape of ophthalmic lens;
- exposing the lens forming resin to polymerization initiating conditions to form a lens from the lens forming resin;
- exposing the lens and the mold part to a first hydration solution comprising about 30% to about 70% isopropyl alcohol for a period of about 10 minutes to about 60 minutes until the lens comprises less than a predetermined threshold of about 300 parts per million of unreacted components and diluents;
- and
- exposing the lens and the mold part to a second hydration solution comprising deionized water to rinse the first hydration solution from the lens.
An automated apparatus for hydrating and leaching an ophthalmic device comprising:
- a) a pallet for transporting one or more lens mold parts, each mold part comprising a lens forming surface and adapted to receive a lens forming mixture for forming an ophthalmic lens;
- b) a deposition mechanism for depositing a lens forming mixture into the lens forming surface;
- c) a curing station functional to expose the lens forming mixture to polymerization initiating conditions to cure the lens forming mixture and form an ophthalmic lens causing the lens to adhere to the mold part;
- d) a hydration station functional to expose the mold and ophthalmic lens to a first hydration solution comprising 30% to 70% isopropyl alcohol for a period of about 10 minutes to 60 minutes until the lens comprises less than about 300 parts per million of unreacted components and diluents and the lens is released from the mold part and expose the lens and the mold part to a second hydration solution comprising deionized water;
- and
- e) a robotic transfer device for transferring one or more pallets and lens mold parts from the curing station to the hydration station.
Dependencies are inferred from the claim text.