Electrode for use in electroretinography
First Claim
1. An electrode for use in electroretinography comprising a thin membrane made of a hydrogel having a thickness from 0.1 to 0.8 mm and a compressive strength of not less than 3000 kg/cm2 and a conductor connected to said thin membrane, said thin membrane being prepared by a process comprising casting an aqueous solution containing more than 8 wt % and not more than 30 wt % of a polyvinyl alcohol having a degree of hydrolysis of not less than 98 mol % and an average polymerization degree of not less than 1000 into a mold having desired shape and dimensions, cooling the cast aqueous solution to a temperature of not higher than minus 10°
- C. to obtain a cooled frozen mass, thawing said cooled frozen mass, and one to seven additional cyclic processing steps each including said cooling and thawing steps.
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Abstract
This invention is directed to an electrode for use in electroretinography. The electrode contains a thin membrane made of a hydrogel of high water content and a conductor connected to the thin membrane. The thin membrane is prepared by casting an aqueous polyvinyl alcohol solution into a mold, freezing the cast aqueous solution to obtain a frozen mass, thawing the frozen mass and subjecting the thawed mass to one to seven additional cyclic freezing and thawing treatments. The thin membrane can also be prepared by subjecting the frozen mass to partial dehydration in a vacuum until the percentage dehydration rate reaches not less than 3 wt %.
47 Citations
16 Claims
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1. An electrode for use in electroretinography comprising a thin membrane made of a hydrogel having a thickness from 0.1 to 0.8 mm and a compressive strength of not less than 3000 kg/cm2 and a conductor connected to said thin membrane, said thin membrane being prepared by a process comprising casting an aqueous solution containing more than 8 wt % and not more than 30 wt % of a polyvinyl alcohol having a degree of hydrolysis of not less than 98 mol % and an average polymerization degree of not less than 1000 into a mold having desired shape and dimensions, cooling the cast aqueous solution to a temperature of not higher than minus 10°
- C. to obtain a cooled frozen mass, thawing said cooled frozen mass, and one to seven additional cyclic processing steps each including said cooling and thawing steps.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An electrode for use in electroretinography comprising a thin membrane made of a hydrogel having a thickness of from 0.1 to 0.8 mm and a compressive strength of not less than 3000 kg/cm2 and a conductor connected to said thin membrane, said thin membrane being prepared by a process comprising casting an aqueous solution containing more than 8 wt % and not more than 30 wt % of a polyvinyl alcohol having a degree of hydrolysis of not less than 98 mol % and an average polymerization degree of not less than 1000 into a mold having desired shape and dimensions, cooling the cast aqueous solution to a temperature of not higher than minus 10°
- C. to obtain a cooled frozen mass, and partially dehydrating the cooled mass of the cast aqueous solution in a vacuum until the percentage dehydration rate reaches not less than 3 wt %.
- View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
Specification