Patent US3470082A successfully refreshed from Google Patents.
Patent EP0601816A2 successfully refreshed from Google Patents.
EP0601816A2
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EP
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CO2 Sensor using a hydrophilic polyurethane matrix
Assignee: Puritan Bennett Corp
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Filing: 1993-12-06
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Granted: —
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Expires: 2013-12-06
Abstract
Abstract The carbon dioxide sensor includes a CO₂ sensing matrix (1) formed from a hydrophilic, gas permeable, crosslinked polyurethane. The polyurethane matrix is formed from a polyurethane pre-polymer mixture which cross links when mixed with an aqueous carbon dioxide buffer solution (3) e.g. HPTS. The dye-buffer solution is physically entrapped as a homogeneous dispersion in the polymer matrix. The matrix is applied to the exposed glass core (7) of an optical fiber, which may first be coated with a primer to allow the polyurethane matrix to bond firmly to the tip of the optical fiber. The hydrophilic polymeric matrix is preferably coated with a hydrophobic material (5) to help avoid leaching of the dye from the matrix, and to prevent diffusion of hydronium ions into the sensing matrix. The hydrophobic polymer overcoat may thereafter be cured by heat treatment. The hydrophobic coating may also contain a light reflective material such as TiO₂.
Inventors
- 👤 Soonkap Hahn
- 👤 Alan Nelson
- 👤 Monte Bennett
- 👤 Henry K. Hui
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 10:51
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/64; G01N21/6428; G01N21/643; A; A61; A61B; A61B5/00; A61B5/145; A61B5/1455; G01N21/75; G01N21/77; G01N21/7703; G01N2021/7706; G01N2021/772; G01N2021/7769; G01N2021/7786
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
81 words
A carbon dioxide sensor comprising: an optical fiber having a surface portion covered with a hydrophilic, gas permeable, cross-linked polymeric matrix containing an aqueous dye-buffer solution physically entrapped in said hydrophilic polymeric matrix, said hydrophilic polymeric matrix formed from a polyurethane pre-polymer compound having a plurality of terminal isocyanate functional groups, said polyurethane pre-polymer compound being cross-linked by addition of said aqueous dye-buffer solution at room temperature; and a layer of a gas permeable, hydrophobic matrial disposed over said hydrophilic matrix.
Claim 2
Dependent Claim
21 words
The carbon dioxide sensor element of Claim 1, wherein the aqueous dye-buffer solution includes a fluorescent dye in a bicarbonate buffer.
Claim 3
Dependent Claim
19 words
The carbon dioxide sensor element of Claim 2, wherein said fluorescent dye is hydroxypyrenetrisulfonic acid or a derivative thereof.
Claim 4
Dependent Claim
19 words
The carbon dioxide sensor element of any preceding claim, wherein said hydrophobic layer of material includes a reflective material.
Claim 5
Dependent Claim
15 words
The carbon dioxide sensor element of Claim 4, wherein said reflective material comprises titanium dioxide.
Claim 6
Dependent Claim
18 words
The carbon dioxide sensor element of any of Claims 1 to 3, wherein said hydrophobic material is silicone.
Claim 7
Independent Claim
147 words
A method of manufacturing a carbon dioxide sensor element including an optical fiber having a surface portion covered with a hydrophilic, gas permeable, cross-linked polymeric matrix containing a homogeneous dispersion of an aqueous dye-buffer solution physically entrapped in said matrix, and a layer of a gas permeable, hydrophobic material disposed over said hydrophilic matrix, comprising the steps of: mixing a hydrophilic, semi-permeable pre-polymer which cross-links in the presence of water with an aqueous dye-buffer solution to form a homogeneous dispersion of said dye-buffer solution in said pre-polymer material and initiate cross-linking of said pre-polymer material; applying said pre-polymer material in which cross-linking has been initiated to said surface portion of said optical fiber; curing pre-polymer material in which cross-linking has been initiated at room termpature, to form said hydrophilic, semi-permeable matrix on said optical fiber; and coating said matrix with a layer of hydrophobic, gas permeable material.
Claim 8
Independent Claim
161 words
A method of manufacturing a carbon dioxide sensor element including an optical fiber having a surface portion covered with a hydrophilic, gas permeable, cross-linked polymeric matrix containing a homogeneous dispersion of an aqueous dye-buffer solution physically entrapped in said matrix, and a layer of a gas permeable, hydrophobic material disposed over said hydrophilic matrix, comprising the steps of: mixing an aqueous dye-buffer solution with a hydrophilic, semi-permeable, polyurethane pre-polymer compound having a plurality of terminal isocyanate functional groups, to form a homogeneous dispersion of said dye-buffer solution in said polyurethane pre-polymer and to initiate cross-linking of said polyurethane pre-polymer to entrap said dye-buffer solution in said pre-polymer material; applying said polyurethane pre-polymer material in which cross-linking has been initiated to said portion of said optical fiber; curing polyurethane pre-polymer material in which cross-linking has been initiated at room temperature, to form said hydrophilic, semi-permeable matrix on said optical fiber; and coating said matrix with a layer of hydrophobic, gas permeable material.
Claim 9
Dependent Claim
14 words
The method of Claim 7 or Claim 8, wherein said pre-polymer comprises polyether polyisocyanate.
Claim 10
Independent Claim
63 words
The method of any of Claims 7 to 9, wherein said optical fiber has distal and proximal ends, and a glass core covered with a cladding material, and further comprising the step of: removing said cladding material from said core at said distal end of the optical fiber prior to said step of applying said pre-polymer material in which cross-linking has been initiated.
Claim 11
Dependent Claim
40 words
The method of Claim 10, further comprising the step of coating the distal end of said optical fiber from which said cladding has been removed with a priming compound before applying said pre-polymer material in which cross-linking has been initiated.
Claim 12
Dependent Claim
11 words
The method of Claim 11, wherein said priming compound comprises 3-isocyanatopropyltriethoxysilane.
Claim 13
Independent Claim
16 words
The method of any of Claims 7 to 12, wherein said hydrophobic material is heat cured.
References Cited (Backward Citations)
No citation records indexed.
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