Carbon dioxide indicator

Claim 2

A carbon dioxide indicator comprising a predominantly hydrophilic polymer matrix selected from the group consisting of alkyl methacrylate, alkyl halide quaternary salt of an alkyl methacrylate, copolymer of an alkyl halide quaternary salt of an alkyl methacrylate, polyurethane, polyvinylpyrrolidone, copolymer of polyvinylpyrrolidone, polyethylene oxide derivatives, copolymers of polyethylene oxide derivatives, polypropylene oxide derivatives, copolymers of polypropylene oxide derivatives, corn starch derivatives, copolymers of corn starch derivatives and any of the above polymers which have been crosslinked, and a pH-sensitive dye which indicates the presence of carbon dioxide comprising o-cresolpthalein or salt thereof present in said matrix, wherein said indicator is in a sufficient amount that it does not change color for at least 15 minutes when said indicator is exposed to normal ambient air, but does change color when said indicator is exposed to exhaled air, a color change in response to exposure to exhaled air being at least about 50 times more rapid than would occur with exposure of the indicator to normal ambient air alone.

Claim 3

The indicator of claim 1 wherein said polymer matrix is a polyurethane foam.

Claim 4

The indicator of claim 1 wherein said pH-sensitive dye is an o-cresolphthalein complexon sodium salt.

Claim 5

The indicator of claim 1 wherein said polymer matrix further comprises a solid desiccant.

Claim 6

The indicator of claim 1 wherein said indicator changes color upon exposure to two or less exhaled breaths of a patient.

Claim 7

The indicator of claim 1 wherein said indicator further comprises a heat-moisture exchanger in said matrix.

Claim 8

The indicator of claim 1 wherein said matrix further comprises less than about 30% by weight of a hydrophobic monomer.

Claim 9

The indicator of claim 1 wherein said matrix further comprises less than about 20% by weight of a hydrophobic monomer.

Claim 10

The indicator of claim 1 wherein said matrix further comprises less than about 10% by weight of a hydrophobic monomer.

Claim 11

The indicator of claim 1 wherein said matrix further comprises less than about 5% by weight of a hydrophobic monomer.

Claim 12

The indicator of claim 1 further including at least one basic salt present in said matrix.

Claim 13

The indicator of claim 11 where said basic salt is sodium hydroxide, potassium phosphate, trisodium phosphate or potassium hydroxide.

Claim 14

The indicator of claim 1 wherein said color change occurs in less than about five seconds of exposure to exhaled air.

Claim 15

The indicator of claim 13 wherein exhaled air has a carbon dioxide concentration of at least about 15 mm of Hg.

Claim 16

The indicator of claim 1 wherein said polymer matrix is UV cured and said matrix further comprises: a UV-curable methyl chloride quaternary salt of at least one methacrylate; a cross-linking agent; and a photoindicator.

Claim 17

The indicator of claim 15 wherein said at least one methacrylate is a dimethylaminoethyl methacrylate.

Claim 18

The indicator of claim 16 wherein said methyl chloride quaternary salt of dimethylaminoethyl methacrylate is at least 70% of said matrix and lauryl methacrylate comprises no more than 30% of the matrix.

Claim 19

The indicator of claim 1 wherein said hydrophilic polymer matrix comprises a hydrogel.

Claim 20

The indicator of claim 18 wherein said hydrogel comprises the methyl chloride quaternary salt of dimethylaminoethyl methacrylate.

Claim 21

The indicator of claim 18 wherein said polymer matrix further comprises a polyurethane foam.

Claim 22

The indicator of claim 1 wherein said matrix is an alkyl methacrylate in which the alkyl portion contains from 1 to about 12 carbon atoms.

Claim 23

The indicator of claim 21 wherein said alkyl methacrylate further comprises a hydrophobic portion of said matrix.

Claim 24

The indicator of claim 22 wherein the ratio of hydrophilic to hydrophobic portions of said matrix is about 2:1 by weight.

Claim 25

The indicator of claim 22 wherein said hydrophilic portion is comprised of an alkyl halide quaternary salt of an alkyl methacrylate.

Claim 26

The indicator of claim 22 wherein said pH-sensitive dye comprises o-cresolphthalein complexon sodium salt.

Claim 27

The indicator of claim 25 further including at least one basic salt present in said matrix.

Claim 28

The indicator of claim 26 wherein said at least one basic salt is sodium hydroxide, potassium phosphate, trisodium phosphate or potassium hydroxide.

Claim 29

The indicator of claim 27 wherein said basic salt is sodium hydroxide.

Claim 30

The indicator of claim 22 wherein said hydrophilic portion is comprised of a methyl chloride quaternary salt of dimethylaminoethyl methacrylate.

Claim 31

The indicator of claim 29 wherein the ratio of hydrophilic to hydrophobic portions of said matrix is about 2:1 by weight.

Claim 32

The indicator of claim 30 wherein the alkyl portion of the hydrophobic alkyl methacrylate contains from 1 to about 8 carbon atoms.

Claim 33

The indicator of claim 30 wherein the alkyl portion of the hydrophobic alkyl methacrylate contains from 1 to about 4 carbon atoms.

Claim 34

The indicator of claim 30 wherein the hydrophobic alkyl methacrylate comprises ethyl methacrylate.

Claim 35

The indicator of claim 33 wherein the hydrophobic alkyl methacrylate further comprises lauryl methacrylate.

Claim 36

The indicator of claim 30 wherein the hydrophobic alkyl methacrylate is a methyl methacrylate.

Claim 37

The indicator of claim 35 wherein the hydrophobic alkyl methacrylate further comprises lauryl methacrylate.

Claim 38

A carbon dioxide indicator device comprising an indicator housing, and an indicator within the housing, said indicator comprising a predominantly hydrophilic polymer matrix selected from the group consisting of alkyl methacrylate, alkyl halide quaternary salt of an alkyl methacrylate, copolymer of an alkyl halide quaternary salt of an alkyl methacrylate, polyurethane, polyvinylpyrrolidone, copolymer of polyvinylpyrrolidone, polyethylene oxide derivatives, copolymers of polyethylene oxide derivatives, polypropylene oxide derivatives, copolymers of polypropylene oxide derivatives, corn starch derivatives, copolymers of corn starch derivatives and any of the above polymers which have been crosslinked, and a pH-sensitive dye which indicates the presence of carbon dioxide comprising o-cresolpthalein or salt thereof present in said matrix, wherein said indicator is in a sufficient amount that it does not change color for at least 15 minutes when said indicator is exposed to normal ambient air, but does change color when said indicator is exposed to exhaled air, a color change in response to exposure to exhaled air being at least about 50 times more rapid than would occur with exposure of the indicator to normal ambient air alone.

Claim 39

A carbon dioxide indicator device comprising an indicator housing, and an indicator within the housing, said indicator comprising a predominantly hydrophilic polymer matrix selected from the group consisting of alkyl methacrylate, alkyl halide quaternary salt of an alkyl methacrylate, copolymer of an alkyl halide quaternary salt of an alkyl methacrylate, polyurethane, polyvinylpyrrolidone, copolymer of polyvinylpyrrolidone, polyethylene oxide derivatives, copolymers of polyethylene oxide derivatives, polypropylene oxide derivatives, copolymers of polypropylene oxide derivatives, corn starch derivatives, copolymers of corn starch derivatives and any of the above polymers which have been crosslinked, and a pH-sensitive dye which indicates the presence of carbon dioxide comprising o-cresolpthalein or salt thereof present in said matrix, wherein said indicator is in a sufficient amount that it does not change color for at least 15 minutes when said indicator is exposed to normal ambient air, but does change color when said indicator is exposed to exhaled air, a color change in response to exposure to exhaled air being at least about 50 times more rapid than would occur with exposure of the indicator to normal ambient air alone.

Claim 40

The device of claim 37 wherein said polymer matrix is a polyurethane foam.

Claim 41

The device of claim 37 wherein said pH-sensitive dye is an o-cresolphthalein complexon sodium salt.

Claim 42

The device of claim 37 wherein said indicator housing is part of an endotracheal tube circuit.

Claim 43

The device of claim 37 wherein said indicator housing is an endotracheal tube.

Claim 44

The device of claim 37 wherein said polymer matrix further comprises a solid desiccant.

Claim 45

The device of claim 37 wherein said indicator housing further is a connector having at least one end capable of being connected to an endotracheal tube.

Claim 46

The device of claim 37 wherein said indicator changes color upon exposure to two or less exhaled breaths of a patient.

Claim 47

The device of claim 37 wherein said housing has an interior surface and said indicator is applied to the interior surface of said housing.

Claim 48

The device of claim 37 wherein said matrix further comprises less than about 30% by weight of a hydrophobic monomer.

Claim 49

The device of claim 37 wherein said matrix further comprises less than about 20% by weight of a hydrophobic monomer.

Claim 50

The device of claim 37 wherein said matrix further comprises less than about 10% by weight of a hydrophobic monomer.

Claim 51

The device of claim 37 wherein said matrix further comprises less than about 5% by weight of a hydrophobic monomer.

Claim 52

The device of claim 37 wherein said indicator further includes at least one basic salt present in said housing.

Claim 53

The device of claim 50 wherein said basic salt is sodium hydroxide, potassium phosphate, trisodium phosphate or potassium hydroxide.

Claim 54

The device of claim 37 wherein said color change occurs in less than about five seconds of exposure to exhaled air.

Claim 55

The device of claim 52 wherein said exhaled air has a carbon dioxide concentration of at least about 15 mm of Hg.

Claim 56

The device of claim 37 wherein said polymer matrix is UV-cured and said matrix further comprises: a UV-curable methyl chloride quaternary salt of at least one methacrylate; a cross-linking agent; and a photoinitiator.

Claim 57

The device of claim 54 wherein said at least one methacrylate is a dimethylaminoethyl methacrylate.

Claim 58

The device of claim 55 wherein the methyl chloride quaternary salt of dimethylaminoethyl methacrylate is at least 70% of said matrix and lauryl methacry-late comprises no more than 30% of the matrix.

Claim 59

The device of claim 37 wherein said hydrophilic polymer matrix comprises a hydrogel.

Claim 60

The device of claim 37 wherein said hydrogel comprises methyl chloride quaternary salt of dimethyl methacrylate.

Claim 61

The device of claim 58 wherein said polymer matrix further comprises a polyurethane foam.