GB2428290A - Monofibre optical meter for chemical measurement - Google Patents
Monofibre optical meter for chemical measurement Download PDFInfo
- Publication number
- GB2428290A GB2428290A GB0514245A GB0514245A GB2428290A GB 2428290 A GB2428290 A GB 2428290A GB 0514245 A GB0514245 A GB 0514245A GB 0514245 A GB0514245 A GB 0514245A GB 2428290 A GB2428290 A GB 2428290A
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- sample
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- film
- parameter
- monofibre
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- 230000003287 optical effect Effects 0.000 title claims abstract description 18
- 238000005259 measurement Methods 0.000 title claims abstract description 12
- 239000000126 substance Substances 0.000 title claims description 14
- 230000005855 radiation Effects 0.000 claims abstract description 13
- 238000000034 method Methods 0.000 claims description 10
- 230000004044 response Effects 0.000 claims description 9
- 230000009467 reduction Effects 0.000 claims description 3
- 230000035945 sensitivity Effects 0.000 claims description 3
- 230000008569 process Effects 0.000 claims description 2
- 230000008859 change Effects 0.000 abstract description 13
- 239000010408 film Substances 0.000 description 31
- 238000000576 coating method Methods 0.000 description 12
- 239000000243 solution Substances 0.000 description 12
- 239000011248 coating agent Substances 0.000 description 11
- 239000000523 sample Substances 0.000 description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 239000000835 fiber Substances 0.000 description 9
- 239000012491 analyte Substances 0.000 description 8
- 239000000463 material Substances 0.000 description 7
- 239000000203 mixture Substances 0.000 description 5
- 239000011521 glass Substances 0.000 description 4
- 238000011835 investigation Methods 0.000 description 4
- 238000002835 absorbance Methods 0.000 description 3
- 239000003513 alkali Substances 0.000 description 3
- 238000005530 etching Methods 0.000 description 3
- 229910017000 As2Se3 Inorganic materials 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 150000004770 chalcogenides Chemical class 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- 239000010453 quartz Substances 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 101100234408 Danio rerio kif7 gene Proteins 0.000 description 1
- 101100221620 Drosophila melanogaster cos gene Proteins 0.000 description 1
- 102000004190 Enzymes Human genes 0.000 description 1
- 108090000790 Enzymes Proteins 0.000 description 1
- 101100398237 Xenopus tropicalis kif11 gene Proteins 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000002419 bulk glass Substances 0.000 description 1
- 239000005387 chalcogenide glass Substances 0.000 description 1
- 238000001311 chemical methods and process Methods 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000007888 film coating Substances 0.000 description 1
- 238000009501 film coating Methods 0.000 description 1
- 238000013467 fragmentation Methods 0.000 description 1
- 238000006062 fragmentation reaction Methods 0.000 description 1
- 230000010365 information processing Effects 0.000 description 1
- 238000002329 infrared spectrum Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000013307 optical fiber Substances 0.000 description 1
- 239000000075 oxide glass Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 238000005240 physical vapour deposition Methods 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 230000001235 sensitizing effect Effects 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B9/00—Measuring instruments characterised by the use of optical techniques
- G01B9/02—Interferometers
- G01B9/02041—Interferometers characterised by particular imaging or detection techniques
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/41—Refractivity; Phase-affecting properties, e.g. optical path length
- G01N21/45—Refractivity; Phase-affecting properties, e.g. optical path length using interferometric methods; using Schlieren methods
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/75—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated
- G01N21/77—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator
- G01N21/7703—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator using reagent-clad optical fibres or optical waveguides
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/75—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated
- G01N21/77—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator
- G01N21/7703—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator using reagent-clad optical fibres or optical waveguides
- G01N2021/7706—Reagent provision
- G01N2021/7723—Swelling part, also for adsorption sensor, i.e. without chemical reaction
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/75—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated
- G01N21/77—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator
- G01N2021/7769—Measurement method of reaction-produced change in sensor
- G01N2021/7779—Measurement method of reaction-produced change in sensor interferometric
Landscapes
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- General Physics & Mathematics (AREA)
- General Health & Medical Sciences (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Plasma & Fusion (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
Abstract
An apparatus is disclosed for determining a parameter of a sample 2 comprising an optical sensor in the form of a monofibre wave guide 3 having a distal end coated with a film 4 that is placed in the sample 2. The waveguide 3 has an input channel connected to the radiation light source 1 and an output channel connected to a photodiode and amplifier 5 to receive signals representative of the interference patterns created at the interface between the film 4 and the sample 2. A computer 7 receives the signals for processing the information and providing a measurement of the parameter. The parameter may be the pH or temperature of a solution 2. The thickness of the film 4 may change in the presence of a sample 2.
Description
Monofibre optical meter for chemical measurement 2428290 Monofibre optical
meter for chemical measurement Inventors J.P. Sharkany, S.O. Korposh, M.Y. Sichka, N.B. Zhitov and J.J.
Ramsden
Background of the invention
The concept of using changes in optical properties of a fibre optic sensor to detect chemical changes in solution has been described in the present art.
However, the method of detection in these cases has been to monitor the absorbance or fluorescence of a surface coating on the sensor tip.
The invention utilises the measurement of changes in interference patterns of layers deposited on the sensor tip. The main advantages of this method are: increased sensitivity compared with absorbance and fluorescence changes; increased robustness, and universality, i.e. the same sensing platform can be used to cover a very wide range of analytes.
Description of the invention
The present invention is directed to fibre-optic sensors, or a module made up of a plurality of such sensor devices, having a reactive film or films deposited on their end surface. The invention is a fibre-optic sensor utilising a refractive film producing an interference system (FIGURE 1).
The invention possesses an optically refractive layer or series of optically refractive layers that are designed to produce a predictable interference pattern due to the combination of reflexions at the interface between the fibre and the layer and the interface between the layer and the ambient medium.
In conventional fibre-optic sensor devices there is a use of a thin film, whose colour, absorbance or fluorescence changes according to the chemical composition of the sample to be measured, without producing an interference pattern.
The basis of the sensor operation is the recording of the signal phase change taking place as a result of the changes of the reactive film thickness d2 and/or the reactive film refractive index (r.i.) 2 due to the interaction of the film with the sample. In a simpler but less informative realisation the amplitude alone of the output channel can be measured as an indication of changes in the sensor film.
The sensor can very conveniently be incorporated into a complete sensing system (FIGURE 2).
Within the film on the sensor end, multiray interference takes place, according to: m2 n2d2=-- (eqnl) Monofibre optical meter for chemical measurement where X the wavelength of the radiation in the optical fibre, and m the number of the interference maximum observed in the film.
The output voltage V of the detector depends linearly on the reflexion coefficient R, i.e. R=,cV. (eqn2) In order to determine the proportionality constant K, i.e. to calibrate the device, the response from a medium of known r.i. needs to be measured. The reflexion coefficient is given by R=(hhlfl3)2 (eqn3) nI + n3 where n1 and n3 are the refractive indices of the quartz monofibre and the medium surrounding its end, respectively. If n is unknown, then the responses from two media of known r.i. need to be measured and the corresponding two eqns 3 solved to find n1. FIGURE 3 shows a typical example of the changes in reflexion occurring when a fibre was plunged from air (n3 1.OO) into water (fl3 1. 33) (at t 1O s) and then withdrawn (at t 60 s).
In order to select a material for sensitizing the fibre end, i.e. that interacts optimally with the sample (experimental medium), a number of requirements have to be met: 1) The film should dissolve in the experimental medium via progressive thinning down. Destruction of the film via fragmentation and release of particles at least as big as the wavelength of the radiation used is to be avoided. Alternatively, the film should swell or contract with penetration of selected components of the experimental medium. A further possibility is for selected components of the sample to form layerwise deposits on the film coating the fibre end.
2) The rate of dissolution or swelling, or their converses, deposition or contraction, should be convenient for the method of recording used.
3) The material must be optically transparent to the radiation used.
4) There must be a practicable method for depositing the film on the ends of the optical fibres.
The performance of interference systems can be predicted by modelling the optical arrangement as a multilayer interference system in which the fibre is a transparent substrate and the film is an optically transparent layer deposited on the substrate. The coefficient of reflexion R123 for such a system is, taking account of the multiray interference of the light beams reflected from the two boundaries of the deposited film (considered as a homogeneous medium located between two homogeneous layers, in general different media): Monofibre optical meter for chemical measurement - (n +n)(n +fl)-4n3nn +(n -n)(n -n)cos2fl (n +n)(n +fl)+4fl3flfl +(n -n)(n -n)cos2/3 where n is the index of refraction of the quartz monofibre, fl2 the index of refraction of the film, fl3 the refraction coefficient of the medium under investigation, and /3_in2d2. (eqn5) From eqn (4) it is clear that the sensitivity of the response towards different concentrations of analyte subtly depends on the material properties of the system, especially the indices of refraction.
In practice it is very important, especially in current medicalbiological investigations, to determine the dynamics of change of the concentrations of the experimental solutions under investigation. Eqn (4) also shows how the rate of change of R123, dR123/dt, will depend on the rate of etching, dd2/dt, which in turn depends on the analyte concentration, and the time dependences of the concentrations can also be conveniently determined by following the time dependence of the differential coefficients.
The sensor comprises a Y-type distributor that divides the power equally between the input and output channels. From the input channel the signal propagates into the common channel, which is placed in contact with the sample. The optical signal is reflected from the interface with the sample and returns into the common channel.
The signal propagates from the common channel into the output channel from which the signal is amplified and processed. The device is as described in FIGURE 1 where a radiation source may be, but is not limited to, a light-emitting diode (1) (emitting a wavelength of 0.95.tm in the present work; any wavelength in ultraviolet, visible or infrared spectral regions is suitable), connected to a Y-shaped monofibre (3) that is coated with a thin film deposit (4). The coated tip is placed in the sample (2) and the reflected light is passed to a photodiode and amplifier (5) and then to an analogue- digital converter (ADC) (6). The signals from the ADC are then passed to a computer (7) for information processing and readout.
In a general embodiment, the invention can be used to analyse the composition of any solution, provided that the optical waveguide or waveguides are coated with an appropriate material. In these embodiments the coating or coatings would selectively and predictably change, e.g. be degraded by active chemical processes, in the presence of the analyte whose concentration it is wished to measure. An example of an active degradation process would be the action of enzymes on the film causing a reduction in thickness of the film. In other embodiments the coating may dissolve in the presence of the analyte, for example in a pH analyser the coating may dissolve in the presence of OW ions. The coating may also increase in thickness in the presence of an analyte which in some embodiments may be polymers that selectively swell in the presence of one or more analytes. In yet other embodiments the coating may be a material with the capacity to adsorb the analyte, hence changing the refractive index of the coating. In all these embodiments, the principle is that one or more interactions between the analyte and the coating change the optical thickness of the coating, and Monofibre optical meter for chemical measurement the concentration of analyte affects either the instantaneous magnitude of the change or the rate of change.
In an embodiment where there are multiple coated sensors, probes can be assembled from bundles of fibres, each coated with a different sensitive film, allowing the measurement of many analytes simultaneously (FIGURE 2). Such bundles can include uncoated reference fibres to allow the measured responses of the measurement fibres to be compensated for bulk refractive index changes of the medium under investigation. Hence, as well as functioning as a chemical or biochemical sensor, the device can also function as a physical sensor to measure parameters such as temperature.
In a particular embodiment the invention is a novel film-coated fibreoptic probe which is capable of continuously determining the pH of solutions by using the amplitude of the interference pattern generated when the probe is immersed in the solution to be investigated. Continuous control of changes in the solutions is also possible. Selectivity of response is achievable by the choice of material for coating the fibre end. In the examples (chalcogenide glasses) presented here, the rate of dissolution of the chalcogenide film in alkaline media depends on the chemical composition of the film and the chemical composition (pH) of the medium under study.
In the embodiment of a pH analyser suitable coating materials are the chalcogenide semiconductor glasses (from the Ge-As-Ge and As-Se-As systems): they are soluble in alkaline media (pH>7), transparent in the near infrared spectrum region and are easily deposited as films. The films of chalcogemde glass are deposited onto the surface of the common channel to a thickness of 3-5 tm.
For use in acid media (pH<7) films of oxide glasses are used, which dissolve even at very low concentrations of the acid substance.
In these particular embodiments bulk glasses are vacuum evaporated onto the surface of many monofibres simultaneously. This serves to produce uniform optical properties, necessary for reproducible mass production of devices.
In general, the thin reactive film may be deposited on the sensor tip by the techniques of physical vapour deposition (reactive and nonreactive sputtering, evaporation, plasma spray), chemical vapour deposition, solgel or other methods known in the art.
Example I
FIGURE 3 shows a typical example of the response of a Ge33As125e55 film deposited on the fibre end to two NaOH solutions (0.1% [1] and 1.0% [2]) of different concentrations (the sudden fluctuations at the boundary between the two solutions are an artifact of transferring the sensor from one solution to the other). Over these short intervals, the change in the interference pattern is almost linear. The monotonous increase of the reflectance with time as etching proceeds is due to the decrease of film thickness, which shifts the interference pattern. When the NaOH concentration is increased tenfold the slope of the reflectance versus time curve increases markedly (region 2 in FIGURE 3). The slopes of short intervals - and mV/s bearing in mind Monofibre optical meter for chemical measurement that the actual numerical values are the voltages output by the photodetector (5 in FIGURE 1) - correspond to pH values of 12.4 and 13.4 respectively. This type of film is useful for rather alkaline solutions.
Example 2
FIGURE 4 shows a typical example of the response of a As2Se3 film deposited on the fibre end to NaOH solutions. Unlike the glass containing Ge (Example 1), As2Se3 glass is known to interact with alkali without disintegrating, and hence a smoothly continuous thinning down of the film is expected. Our results confirm this expectation, i.e. the noise amplitude is much lower than in FIGURE 3, in which disintegration is taking place and the predicted sinusoidal interference pattern (cf. eqn 4) is now observed, in contrast to FIGURE 3. The rate of the phase change for the given etching process, and correspondingly the change of the interference pattern, greatly depend on the alkali solution concentration. In FIGURE 4 it can be seen that at a small alkali concentration (region 1) the rate of the phase change is several times smaller than at the larger concentration (region 2, compare especially the second half with the change in region 1). The reversibility of the response was verified by adding distilled water to the medium (region 3), and a reversion to the kinetics characteristic of region 1 was noted. It may be advantageous to mechanically mix the solution.
Claims (26)
1. Apparatus for determining a parameter of a sample, the apparatus comprising at least one optical sensor in the form of a waveguide having a distal end that, in use, is placed in contact with a sample, and is adapted to produce an interference pattern at the interface with the sample representative of a parameter of the sample.
2. Apparatus according to claim 1 wherein the distal end of the waveguide is provided with a reactive film comprising one or more optically refractive layers configured to produce a predictable interference pattern at the interface with the sample.
3. Apparatus according to claim 2 wherein the waveguide comprises a monofibre on which the reactive film is deposited.
4. Apparatus according to claim 3 wherein the monofibre and reactive film are transparent.
5. Apparatus according to any preceding claim 4 wherein the thickness of the reactive film changes in the presence of the sample.
6. Apparatus according to claim 5 wherein the film dissolves to produce a reduction in thickness of the film.
7. Apparatus according to claim 5 wherein the film swells or contracts to produce an increase or reduction in thickness of the film.
8. Apparatus according to claim 5 wherein the film is deposited to produce an increase in thickness of the film.
9. Apparatus according to any preceding claim wherein the sensor comprises a Y-type distributor having an input channel, an output channel and a common channel wherein the common channel is placed in contact with the sample.
10. Apparatus according to claim 9 wherein the input channel provides an input signal to the common channel that is reflected from the interface with the sample and provides an output signal via the common channel to the output channel.
11. Apparatus according to claim 10 wherein the input signal is provided by a radiation source.
12. Apparatus according to claim 11 wherein the radiation source is an LED light source.
13. Apparatus according to claim 11 or claim 12 wherein the output signal is provided to a radiation detector.
14. Apparatus according to claim 12 wherein the radiation detector is a photodiode.
15. Apparatus according to claim 11 or claim 12 wherein the radiation detector provides an output to a computer via an amplifier and an analogue-digital converter (ADC), the computer being operable to process information from the radiation detector and provide a measurement of the parameter of the sample.
16. Apparatus according to any preceding claim comprising a plurality of sensors each comprising a monofibre waveguide.
17. Apparatus according to claim 16 wherein at least one sensor is a reference sensor.
18. Apparatus according to claim 16 or claim 17 wherein each sensor has a different sensitivity.
19. Apparatus according to any preceding claim wherein the sensor is a chemical or biochemical sensor.
20. Apparatus according to claim 19 wherein the sensor is a pH sensor.
21. Apparatus according to any of claims 1 to 18 wherein the sensor is a physical sensor.
22. Apparatus according to claim 21 wherein the sensor is a temperature sensor.
23. Apparatus for determining a parameter of a sample substantially as hereinbefore described with reference to the accompanying drawings.
24. A sensor for use in the apparatus according to any preceding claim, the sensor comprising an optical waveguide having a distal end having a reactive film that, in use, is placed in contact with a sample and produces an interference pattern representative of a parameter of the sample in response to exposure to a radiation source.
25. A method of determining a parameter of a sample comprising providing an optical sensor, placing a distal end of the sensor in contact with a sample, producing an interference pattern at the interface between the distal end and the sample with a radiation source, and using the interference pattern to determine a parameter of the sample.
26. A method of determining a parameter of a sample substantially as hereinbefore described with reference to the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0514245A GB2428290B (en) | 2005-07-12 | 2005-07-12 | Monofibre optical meter for chemical measurement |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0514245A GB2428290B (en) | 2005-07-12 | 2005-07-12 | Monofibre optical meter for chemical measurement |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB0514245D0 GB0514245D0 (en) | 2005-08-17 |
| GB2428290A true GB2428290A (en) | 2007-01-24 |
| GB2428290B GB2428290B (en) | 2010-09-01 |
Family
ID=34897077
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0514245A Active GB2428290B (en) | 2005-07-12 | 2005-07-12 | Monofibre optical meter for chemical measurement |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2428290B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104568946A (en) * | 2015-01-23 | 2015-04-29 | 中国农业大学 | Intelligent optical fiber pH sensor |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2096784A (en) * | 1981-04-09 | 1982-10-20 | Standard Telephones Cables Ltd | Optical fibre temperature sensors |
| US5804453A (en) * | 1996-02-09 | 1998-09-08 | Duan-Jun Chen | Fiber optic direct-sensing bioprobe using a phase-tracking approach |
| US6141098A (en) * | 1996-01-29 | 2000-10-31 | Sentec Corporation | Fiber optic temperature sensor |
| WO2001036945A1 (en) * | 1999-11-18 | 2001-05-25 | Farfield Sensors Limited | Sensor device |
| GB2385915A (en) * | 2001-10-19 | 2003-09-03 | Optomed As | Fibre optic sensing of measurands within the body |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7445887B2 (en) * | 2005-01-07 | 2008-11-04 | Fortebio, Inc. | Enzyme activity measurements using bio-layer interferometry |
-
2005
- 2005-07-12 GB GB0514245A patent/GB2428290B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2096784A (en) * | 1981-04-09 | 1982-10-20 | Standard Telephones Cables Ltd | Optical fibre temperature sensors |
| US6141098A (en) * | 1996-01-29 | 2000-10-31 | Sentec Corporation | Fiber optic temperature sensor |
| US5804453A (en) * | 1996-02-09 | 1998-09-08 | Duan-Jun Chen | Fiber optic direct-sensing bioprobe using a phase-tracking approach |
| WO2001036945A1 (en) * | 1999-11-18 | 2001-05-25 | Farfield Sensors Limited | Sensor device |
| GB2385915A (en) * | 2001-10-19 | 2003-09-03 | Optomed As | Fibre optic sensing of measurands within the body |
Also Published As
| Publication number | Publication date |
|---|---|
| GB0514245D0 (en) | 2005-08-17 |
| GB2428290B (en) | 2010-09-01 |
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