Patent US1504882A successfully refreshed from Google Patents.
Patent EP0228692A2 successfully refreshed from Google Patents.
EP0228692A2
Expired / Lapsed
EP
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skin marker
Assignee: Eneos Corp
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Filing: 1986-12-23
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Granted: —
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Expires: 2006-12-23
Abstract
Abstract A skin marker is provided for diagnosis by X-ray tomography and nuclear magnetic resonance imaging. The skin marker is composed of a vessel in which a non-magnetic and X-ray radioopaque material is dispersed, and a hydrogel of high water content filled in the vessel. The hydrogel is prepared by a process comprising a casting step of casting into the vessel an aqueous solution containing more than 8 wt% and not more than 20 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 1,000, a freezing step of cooling the cast aquesous solution to a temperature of not higher than - (minus)n 10°C to obtain a frozen mass, a thawing step of thawing the frozen mass, and one to seven additional cyclic processing steps each including the freezing and thawing steps.
Inventors
- 👤 Masao Nambu
- 👤 Nobuichi Makino
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 20:37
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/5601; A; A61; A61K; A61K49/00; A61K49/04; A61K49/06; A61K49/18; A61K49/1803; G01R33/58
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
139 words
A skin marker for diagnosis by X-ray tomography and nuclear magnetic resonance imaging, comprising a vessel in which a non-magnetic and X-ray radioopaque material is dispersed, and a hydrogel of high water content filled in said vessel, said hydrogel being prepared by a process comprising a casting step of casting into said vessel an aqueous solution containing more than 8 wt% and not more than 20 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 1,000, a freezing step of cooling the cast aquesous solution to a temperature of not higher than - (minus) 10°C to obtain a frozen mass, a thawing step of thawing said frozen mass, and one to seven additional cyclic processing steps each including said freezing and thawing steps.
Claim 2
Dependent Claim
139 words
A skin marker for diagnosis by X-ray tomography and nuclear magnetic resonance imaging, comprising a vessel in which a non-magnetic and X-ray radioopaque material is dispersed, and a hydrogel of high water content filled in said vessel, said hydrogel being prepared by a process comprising a casting step of casting into said vessel an aqueous solution containing more than 8 wt% and not more than 20 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 1,000, a freezing step of cooling the cast aquesous solution to a temperature of not higher than - (minus) 10°C to obtain a frozen mass, a thawing step of thawing said frozen mass, and one to seven additional cyclic processing steps each including said freezing and thawing steps.
Claim 3
Dependent Claim
35 words
The skin marker according to claim 1, wherein said vessel is made of a material to be easily cut, said material being selected from the group consisting of synthetic resins and natural and synthetic rubbers.
Claim 4
Dependent Claim
30 words
The skin marker according to claim 2, wherein said synthetic resin is selected from the group consisting of polyethylene, polypropylene, polyamides, polyvinylchloride, polyvinylidene chcloride, polyesters, polyacrylonitrile, polyfluoroethylene, and silicone resins.
Claim 5
Dependent Claim
29 words
The skin marker according to claim 1, wherein said non-magnetic and X-ray radioopaque material is dispersed in said vessel in a mixing ratio of from 10 to 45 wt%.
Claim 6
Dependent Claim
30 words
The skin marker according to claim 1, wherein said non-magnetic and X-ray radioopaque material is selected from the group consisting of barium sulfate, silicon carbide, silicon nitride, alumina and zirconia.
Claim 7
Dependent Claim
33 words
The skin marker according to claim 1, wherein said hydrogel is added with an additive which neither hinders gelation of said polyvinyl alcohol nor attenuates the proton NMR signal emitted from said hydrogel.
Claim 8
Dependent Claim
26 words
The skin marker according to claim 6, wherein said additive is added in an amount of not more than 1/2 of the weight of said hydrogel.
Claim 9
Dependent Claim
32 words
The skin marker according to claim 6, wherein said additive is selected from the group consisting of lecithin, iodine, vegetable oils, animal oils, glucose, casein, methyl alcohol, propyl alcohol and butyl p-hydroxybenzoate.
Claim 10
Dependent Claim
25 words
The skin marker according to claim 6, wherein said additive is selected from the group consisting of nickel, vanadyl, iron (III), dysprosium, cobalt and gadolinium.
Claim 11
Dependent Claim
20 words
The skin marker according to claim 1, wherein said hydrogel has a water content of from 80 to 92 wt%.
References Cited (Backward Citations)
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