US5242835A
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US
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Method and apparatus for determining the concentration of oxygen
Assignee: Radiometer AS
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Filing: 1992-07-21
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Granted: 1993-09-07
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Expires: 2012-07-21
Abstract
Abstract The concentration of molecular oxygen in a sample is determined by exciting oxygen molecules of the sample from the electronic ground state to the excited 1 Δ g state (excited singlet state), measuring a 1270-nm luminescence characteristic of the excited oxygen molecules (singlet oxygen) and correlating the luminescence characteristic measured with the concentration of molecular oxygen in the sample. Normally, the 1270-nm luminescence characteristic is the 1270-nm luminescence intensity. Preferably, the oxygen molecules are excited by being subjected to diffusion contact with a sensitizer such as a porphyrin or a porphyrin-related compound, e.g. a transition metal complex of a porphyrin. The sensitizer is brought into an oxygen-exciting electronic state by absorption of electromagnetic radiation such as light, the oxygen-exciting electronic state optionally being adapted to the measuring system employed by means of a quencher such as a substituted polyene. The sensitizer may be present in an organic solvent or a polymer such as polyvinylchloride. The oxygen-containing sample is preferably a sample of biological origin such as a blood sample.
Inventors
- 👤 Niels-Henrik Jensen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:06
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/64; G01N21/6428; G01N21/643; G01N21/645; G01N2021/6482; G01N35/00; G01N35/10; G01N2035/1027; G01N2035/1048; G01N2035/1062; G01N21/17; G01N21/25; G01N21/27; G01N21/274; Y; Y10; Y10T; Y10T436/00; Y10T436/20; Y10T436/207497
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
141 words
A method of determining the concentration of ground state molecular oxygen in a test sample, said method comprising: (a) exciting oxygen molecules of the test sample from the electronic ground state to the excited 1 Δ g state (excited singlet state), (b) measuring a 1270-nm luminescence characteristic of the excited oxygen molecules in the test sample, (c) quantitatively correlating the measured 1270-nm luminescence characteristic with standard values determined on the basis of a positive quantitative correlation between (i) 1270-nm luminescence signals of excited oxygen molecules in reference samples having known, pre-selected concentrations of ground state molecular oxygen and (ii) the concentrations of ground state molecular oxygen in the reference samples, and (d) quantifying the content of ground state molecular oxygen in the test sample on the basis of the quantitative correlation of the measured 1270-nm luminescence characteristic with the standard values.
Claim 2
Independent Claim
141 words
A method of determining the concentration of ground state molecular oxygen in a test sample, said method comprising: (a) exciting oxygen molecules of the test sample from the electronic ground state to the excited 1 Δ g state (excited singlet state), (b) measuring a 1270-nm luminescence characteristic of the excited oxygen molecules in the test sample, (c) quantitatively correlating the measured 1270-nm luminescence characteristic with standard values determined on the basis of a positive quantitative correlation between (i) 1270-nm luminescence signals of excited oxygen molecules in reference samples having known, pre-selected concentrations of ground state molecular oxygen and (ii) the concentrations of ground state molecular oxygen in the reference samples, and (d) quantifying the content of ground state molecular oxygen in the test sample on the basis of the quantitative correlation of the measured 1270-nm luminescence characteristic with the standard values.
Claim 3
Dependent Claim
16 words
A method according to claim 1 wherein the 1270-nm luminescence characteristic is the 1270-nm luminescence intensity.
Claim 4
Dependent Claim
56 words
A method according to claim 1 wherein the excitation of the ground state oxygen molecules is performed by means of a sensitizing agent having an excited electronic state (sensitizing excited state) capable of exciting molecular oxygen from the electronic ground state to the excited singlet state, the sensitizing agent being in diffusion contact with the sample.
Claim 5
Dependent Claim
22 words
A method according to claim 3 wherein the energy of the excited state of the sensitizing agent is higher than 0.98 eV.
Claim 6
Dependent Claim
64 words
A method according to claim 3 wherein the sensitizing agent comprises a sensitizer having an excited state capable of exciting molecular oxygen from the electronic ground state to the excited singlet state and a quencher capable of deactivating the excited state of the sensitizer so as to reduce the excited state lifetime of the sensitizer, the quencher being in diffusion contact with the sensitizer.
Claim 7
Dependent Claim
20 words
A method according to claim 3 wherein the sensitizing excited state of the sensitizing agent is the excited triplet state.
Claim 8
Dependent Claim
29 words
A method according to claim 3 wherein the diffusion contact between the sensitizing agent and the sample is established at an interface between the sensitizing agent and the sample.
Claim 9
Dependent Claim
36 words
A method according to claim 3 wherein the oxidation potential of the excited state of the sensitizing agent is of a size which essentially renders the sensitizing agent incapable of converting molecular oxygen to the superoxide.
Claim 10
Dependent Claim
27 words
A method according to claim 8 wherein the oxidation potential of the excited state of the sensitizing agent is higher than -0.7 V versus saturated Calomel Electrode.
Claim 11
Dependent Claim
21 words
A method according to claim 3 wherein the sensitizing agent is selected from the group consisting of porphyrins and porphyrin-related compounds.
Claim 12
Dependent Claim
25 words
A method according to claim 10 wherein the sensitizing agent is selected from the group consisting of metal-free porphyrins, metallo-porphyrins, phtalocyanins, metallo-phtalocyanins and derivatives thereof.
Claim 13
Dependent Claim
15 words
A method according to claim 3 wherein the sensitizing agent is embedded in a matrix.
Claim 14
Dependent Claim
13 words
A method according to claim 12 wherein the matrix comprises an organic solvent.
Claim 15
Dependent Claim
31 words
A method according to claim 12 wherein the matrix in which the sensitizing agent is embedded is free of OH-groups so as to maximize the luminescence intensity of excited singlet oxygen.
Claim 16
Dependent Claim
42 words
A method according to claim 12 wherein the diffusion contact between the sensitizing agent and the sample is established through a membrane which separates said matrix containing the sensitizing agent and the sample containing the ground state molecular oxygen to be measured.
Claim 17
Dependent Claim
12 words
A method according to claim 12 wherein the matrix comprises a polymer.
Claim 18
Dependent Claim
60 words
A method according to claim 12 wherein the sensitizing agent and the matrix in which it is present are selected so as to affect the excited state lifetime of the sensitizing agent and the oxygen permeability of the matrix to thereby obtain a luminescence characteristic of a sufficient size variation over the ground state oxygen concentration range to be measured.
Claim 19
Dependent Claim
65 words
A method according to claim 17 wherein the sensitizing agent and the matrix in which it is present are adapted to a particular maximum ambient oxygen concentration to be measured so that a matrix oxygen concentration of at the most 50 • [O 2 ] 1/2 will be obtained on contacting the matrix with a sample of the particular maximum ambient ground state oxygen concentration.
Claim 20
Dependent Claim
23 words
A method according to claim 18 wherein a matrix oxygen concentration of at the most 20 • [O 2 ] 1/2 is obtained.
Claim 21
Dependent Claim
23 words
A method according to claim 18 wherein a matrix oxygen concentration of at the most 10 • [O 2 ] 1/2 is obtained.
Claim 22
Dependent Claim
29 words
A method according to claim 3 wherein the excited state of the sensitizing agent is formed from another electronic state of the sensitizing agent by absorption of electromagnetic radiation.
Claim 23
Dependent Claim
19 words
A method according to claim 21 wherein the electromagnetic radiation is of a wavelength of less than 1270 nm.
Claim 24
Dependent Claim
20 words
A method according to claim 22 wherein the electromagnetic radiation is of a wavelength in the range of 300-1000 nm.
Claim 25
Dependent Claim
16 words
A method according to claim 22 wherein the sensitizing agent is selected from transition metal complexes.
Claim 26
Dependent Claim
25 words
A method according to claim 24 wherein the sensitizing agent is selected from the group consisting of complexes of Zn(II), Pd(II), Pt(II), Ru(II) and Os(II).
Claim 27
Independent Claim
158 words
A method of determining the concentration of ground state molecular oxygen in a test sample which is a fluid sample of biological origin having a molecular oxygen concentration at a physiological level, said method comprising: (a) exciting oxygen molecules of the test sample from the electronic ground state to the excited 1 Δ g state (excited singlet state), (b) measuring a 1270-nm luminescence characteristic of the excited oxygen molecules in the test sample, (c) quantitatively correlating the measured 1270-nm luminescence characteristic with standard values determined on the basis of a positive quantitative correlation between (i) 1270-nm luminescence signals of excited oxygen molecules in reference samples having known, pre-selected concentrations of ground state molecular oxygen and (ii) the concentrations of ground state molecular oxygen in the reference samples, and (d) quantifying the content of ground state molecular oxygen in the test sample on the basis of the quantitative correlation of the measured 1270-nm luminescence characteristic with the standard values.
Claim 28
Independent Claim
158 words
A method of determining the concentration of ground state molecular oxygen in a test sample which is a fluid sample of biological origin having a molecular oxygen concentration at a physiological level, said method comprising: (a) exciting oxygen molecules of the test sample from the electronic ground state to the excited 1 Δ g state (excited singlet state), (b) measuring a 1270-nm luminescence characteristic of the excited oxygen molecules in the test sample, (c) quantitatively correlating the measured 1270-nm luminescence characteristic with standard values determined on the basis of a positive quantitative correlation between (i) 1270-nm luminescence signals of excited oxygen molecules in reference samples having known, pre-selected concentrations of ground state molecular oxygen and (ii) the concentrations of ground state molecular oxygen in the reference samples, and (d) quantifying the content of ground state molecular oxygen in the test sample on the basis of the quantitative correlation of the measured 1270-nm luminescence characteristic with the standard values.
Claim 29
Dependent Claim
15 words
A method according to claim 26 wherein the fluid sample of biological origin is blood.
Claim 30
Dependent Claim
17 words
A method according to claim 26 wherein the fluid sample is an oxygen-containing gas of biological origin.
Claim 31
Independent Claim
154 words
A system for determining the concentration of ground state molecular oxygen in a test sample, said system comprising: (a) means for exciting oxygen molecules of the test sample from the electronic ground state to the excited 1 Δ g state (excited singlet state), said means comprising an electromagnetic radiation source and a sensitizing agent, said sensitizing agent being in diffusion contact with the sample, (b) means for measuring a 1270-nm luminescence characteristic of the excited oxygen molecules in the test sample, and (c) means for quantifying the content of ground state molecular oxygen in the test sample based on a quantitative correlation of the measured 1270-nm luminescence characteristic with standard values determined on the basis of a positive quantitative correlation between (i) 1270-nm luminescence signals of excited oxygen molecules in reference samples having known, pre-selected concentrations of ground state molecular oxygen and (ii) the concentrations of ground state molecular oxygen in the reference samples.
Claim 32
Independent Claim
154 words
A system for determining the concentration of ground state molecular oxygen in a test sample, said system comprising: (a) means for exciting oxygen molecules of the test sample from the electronic ground state to the excited 1 Δ g state (excited singlet state), said means comprising an electromagnetic radiation source and a sensitizing agent, said sensitizing agent being in diffusion contact with the sample, (b) means for measuring a 1270-nm luminescence characteristic of the excited oxygen molecules in the test sample, and (c) means for quantifying the content of ground state molecular oxygen in the test sample based on a quantitative correlation of the measured 1270-nm luminescence characteristic with standard values determined on the basis of a positive quantitative correlation between (i) 1270-nm luminescence signals of excited oxygen molecules in reference samples having known, pre-selected concentrations of ground state molecular oxygen and (ii) the concentrations of ground state molecular oxygen in the reference samples.
Claim 33
Dependent Claim
21 words
A system according to claim 29 wherein the sensitizing agent is embedded in a matrix, the matrix being an organic solvent.
Claim 34
Dependent Claim
18 words
A system according to claim 29 wherein said means for quantifying comprises a signal or data processing means.
Claim 35
Dependent Claim
30 words
A system according to claim 29 wherein the sensitizing agent has an excited electronic state capable of exciting molecular oxygen from the electronic ground state to the excited singlet state.
Claim 36
Dependent Claim
24 words
A system according to claim 32 wherein the sensitizing agent has an excited electronic state, the energy of which is higher than 0.98 eV.
Claim 37
Dependent Claim
19 words
A system according to claim 29 wherein the electromagnetic radiation is of a wavelength of less than 1270 nm.
Claim 38
Dependent Claim
21 words
A system according to claim 34 wherein the electromagnetic radiation is of a wave length in the range of 300-1000 nm.
Claim 39
Dependent Claim
37 words
A system according to claim 29 wherein the means for measuring a 1270-nm luminescence characteristic of the excited oxygen molecules comprises a detector being capable of measuring said luminescence characteristic at a wavelength of about 1270 nm.
Claim 40
Dependent Claim
14 words
A system according to claim 36, wherein said detector is covered by a filter.
Claim 41
Dependent Claim
15 words
A system according to claim 36 wherein said detector is connected to an amplifier circuit.
Claim 42
Dependent Claim
15 words
A system according to claim 29 wherein the sensitizing agent is embedded in a matrix.
Claim 43
Dependent Claim
60 words
A system according to claim 39 wherein the sensitizing agent and the matrix in which it is present are selected so as to affect the excited state lifetime of the sensitizing agent and the oxygen permeability of the matrix to thereby obtain a luminescence characteristic of a sufficient size variation over the ground state oxygen concentration range to be measured.
Claim 44
Dependent Claim
42 words
A system according to claim 39 wherein the diffusion contact between the sensitizing agent and the sample is established through a membrane which separates said matrix containing the sensitizing agent and the sample containing the ground state molecular oxygen to be measured.
Claim 45
Dependent Claim
18 words
A system according to claim 39 wherein the matrix is a polymer which is free of OH groups.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-09-06 | 1997-03-08 | 1997-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-09-06 | 2001-03-08 | 2001-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-09-06 | 2005-03-08 | 2005-09-07 | $7700.00 | Window Closed / Lapsed |