DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Inventorship
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Response to Amendment
Applicant's Amendment filed 8/7/2025 has been fully considered and entered.
Response to Arguments
Applicant’s arguments, see Remarks pages 6-8, filed 8/7/2025, with respect to the rejection(s) of claim(s) 1, 3-11, and 13-15 under 102(a)(1) and 103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of newly found prior art which teaches an erosion sensor and reference Bragg gratings, and which would have been obvious to combine to meet the claimed limitations.
Claim Objections
Claim 1 is objected to because of the following informalities: a period needs to be added at the end of claim 1. Appropriate correction is required.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 1, 3, 5-11, and 13-15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Xia in CN104482876A (hereinafter "Xia") in view of Grattan et al. in US 20050111793 A1 (hereinafter "Grattan").
Regarding claims 1, 3, 6, 10-11, and 13, Xia discloses a Bragg grating erosion sensor (fiber optic grating sensor 2 is interpreted as a Bragg grating erosion sensor since it uses Bragg gratings in a system designed to measure amounts of erosion; see Fig. 2) comprising:
one or more optical fibres (optical cable 12), each optical fibre comprising one or more cores (12 contains a necessarily present core) and an optical sheath surrounding the one or more cores (fiber optic cladding 11 is interpreted as an optical sheath surrounding the necessarily present core; see Fig. 2 where core and cladding are drawn; note that chirped grating 10 is present within the core),
a variable pitch measurement Bragg grating (the chirped grating 10 is interpreted as a variable pitch measurement grating since it is defined with a non-continuous, i.e. variable, grating period; see the top of page 4 of the translation; note that “chirped” is commonly understood to refer to variation in the pitch) inscribed (inscribed is interpreted as imparting information to the core, likened to how data is “written” to memory) in one of the cores of one of the optical fibres (see Fig. 2) and which defines a measurement section to be eroded (the section of 10 at the end of sensor 2 is interpreted as a measurement section since it is eroded as the surrounding concrete 9 is eroded; see Fig. 2),
one or more reference Bragg gratings (the computer-stored initial reading, i.e. pre-stored spectral curves, of chirped grating 10 before erosion is interpreted as a reference grating; see page 4, lines 6-7), each reference Bragg grating being inscribed in one of the cores of one of the optical fibres (see Fig. 2), and
a processing unit (data processing module 5 is interpreted as a processing unit) configured to measure a spectral width of radiation reflected by the measurement Bragg grating (see Fig. 3-4 which show the reflection spectrum with varying amounts of erosion), to measure a wavelength of radiation reflected by at least one reference Bragg grating (the initial stored reference measurement of 0mm), and determine a physical length of the measurement section according to the spectral width of the radiation reflected by the measurement Bragg grating and the wavelength of the radiation reflected by the at least one reference Bragg grating (since the device is capable of obtaining a corresponding erosion depth value, it is interpreted as capable of determining a physical length of the measurement section; Xia relies upon spectral curves for this determination; see page 3, lines 1-2; see page 4, lines 6-7), but fails to teach:
wherein at least one of the one or more reference Bragg gratings is a constant pitch Bragg grating (claim 1);
wherein the measurement Bragg grating and at least one of the one or more reference Bragg gratings are inscribed in a same core of an optical fibre (claim 3);
wherein each reference Bragg grating inscribed in the reference core is arranged to reflect radiation in a wavelength range comprised in a range of wavelengths reflected by the measurement Bragg grating (claim 6);
wherein the one or more reference Bragg gratings comprise a plurality of second reference Bragg gratings distributed along the measurement section (claim 10);
wherein one of the one or more optical fibres comprises a measurement core and a reference core, the measurement Bragg grating being inscribed in the measurement core and the second reference Bragg gratings being inscribed in the reference core, each second reference Bragg grating having a pitch equal to a local pitch of the measurement Bragg grating (claim 11); and
wherein the processing unit is configured to determine the physical length of the measurement section according to the spectral width of the radiation reflected by the measurement Bragg grating and to a wavelength difference between a wavelength of the radiation reflected by the measurement Bragg grating and the wavelength of the radiation reflected by the at least one reference Bragg grating (claim 13).
Grattan teaches a similar device (fibre Bragg grating sensor):
wherein at least one of the one or more reference Bragg gratings is a constant pitch Bragg grating (Grattan relies upon standard, i.e. non-chirped or uniform period, fibre Bragg gratings with “substantially identical grating periods”, see the Abstract and Para. 12; see Para. 17 which includes a reference fibre Bragg grating; note Para. 41) (claim 1);
wherein the measurement Bragg grating and at least one of the one or more reference Bragg gratings are inscribed in a same core of an optical fibre (see Para. 12-13; see Fig. 3 where a variety of Bragg gratings are provided; note that all gratings are not reference gratings; note that all gratings are provided in the same fibre optic cable and thus in the same core) (claim 3); and
wherein each reference Bragg grating inscribed in the reference core is arranged to reflect radiation in a wavelength range comprised in a range of wavelengths reflected by the measurement Bragg grating (see the end of Para. 17; note Para. 39-40) (claim 6); and
wherein the one or more reference Bragg gratings (reference fibre Bragg gratings; see Para. 40) comprise a plurality of second reference Bragg gratings (reference fibre Bragg gratings implies that at least 2 reference Bragg gratings are present; see Para. 40) distributed along the measurement section (Zones A, B, and C) (claim 10);
wherein one of the one or more optical fibres comprises a measurement core (any core section containing the chirped grating is interpreted as a measurement core) and a reference core (any core section containing the uniform grating is interpreted as a reference core), the measurement Bragg grating being inscribed in the measurement core and the second reference Bragg gratings being inscribed in the reference core (the respective gratings are interpreted as being inscribed in their respective core sections), each second reference Bragg grating having a pitch equal to a local pitch of the measurement Bragg grating (the pitch of all gratings within a particular zone are identical; see Para. 34 ) (claim 11); and
wherein the processing unit is configured to determine the physical length of the measurement section according to the spectral width of the radiation reflected by the measurement Bragg grating and to a wavelength difference between a wavelength of the radiation reflected by the measurement Bragg grating and the wavelength of the radiation reflected by the at least one reference Bragg grating (Grattan would implicitly use the spectral width and wavelength difference to perform the physical length determination of the measurement section; see Para. 15 and 30-42) (claim 13).
Accordingly, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have used at least one separate reference Bragg grating with a constant pitch as taught by Grattan in the erosion sensor of Xia for the purpose of actively correcting drifting measurements in the sensor, such as compensating for temperature fluctuations, thereby achieving reduced measurement error and increased precision and/or sensitivity, which is something that Xia alone is not capable of since Xia relies solely on pre-stored reference data for comparison and is not representative of the system in changing environments.
Regarding claim 5, Xia/Grattan discloses the erosion sensor according to claim 1 as discussed above, wherein one of the one or more optical fibres comprises a measurement core (any core section containing the chirped grating is interpreted as a measurement core) and a reference core (any core section containing the uniform grating is interpreted as a reference core), the measurement Bragg grating being inscribed in the measurement core and at least one of the one or more reference Bragg gratings being inscribed in the reference core (the respective gratings are interpreted as being inscribed in their respective core sections).
Regarding claim 7, Xia/Grattan discloses the erosion sensor according to claim 1 as discussed above, wherein the measurement section (the section to be eroded is between the light source and the direction of erosion 8; see Fig. 2) extends between a proximal end (the end nearest the light source is interpreted as the proximal end), arranged to receive incident radiation (light must enter the fiber from this end in order to work as intended), and a distal end (the end at the concrete surface 9), arranged to be eroded (see Fig. 2; note the direction of erosion 8), the one or more reference Bragg gratings comprising a first reference Bragg grating inscribed on a first reference section (any section containing a reference Bragg grating is interpreted as comprising the first reference Bragg grating on the first reference section) located in a vicinity of the proximal end (all sections are interpreted as being within the vicinity of the proximal end as well as the distal end).
Regarding claims 8 and 9, Xia/Grattan discloses the erosion sensor according to claim 7 as discussed above, but fails to teach:
wherein the first reference section is located upstream of the measurement section (claim 8); or
wherein the first reference section is included in the measurement section (claim 9).
Grattan teaches locating the first reference section upstream of the measurement section (Para. 35 describes how the sensor will always detect the closest Bragg grating; if a person having ordinary skill in the art wants to always reduce the amount of error in the system, they will elect to put the reference section first; Additionally, in order to keep the reference grating at a known temperature and stress, as in Para. 41, the person having ordinary skill in the art would have known to keep the grating away from the end performing the erosion and would not have considered the reference Bragg gratings as sacrificial as compared to the measurement Bragg gratings) (claim 8).
Grattan also teaches that each measurement section (Zone A, B, and C for example) may have at least one reference peak per zone, thus implying that the first reference section (any section capable of creating a reference peak is interpreted as a reference section, so the first reference section is interpreted as the section of Zone A that produces a reference peak) could alternatively be included in the measurement section (Zones A, B, and C; see the end of Para. 40) (claim 9).
Accordingly, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have the first reference section upstream of the measurement section as taught by Grattan in the device combination suggested by Xia/Grattan for the purpose of providing a reference section for the entire useful life of the device thereby achieving a device capable of increased accuracy for as long as possible, or alternatively, could have had the first reference section included in the measurement section as taught by Grattan in the device combination suggested by Xia/Grattan for the purpose of capturing a reference peak experiencing conditions as similar as possible to each measurement signal, thus obviating some undesirable error for each signal collected.
Regarding claim 14, Xia/Grattan discloses the erosion sensor according to claim 10 as discussed above, wherein the processing unit (the combined processing unit of Xia/Grattan which is capable of using multiple radiation reflections from a variety of Bragg gratings) is configured to measure a wavelength of the radiation reflected by each of the second reference Bragg gratings (Xia and Grattan both measure and process wavelengths of reflected radiation; Grattan specifically uses second reference Bragg gratings; see the rejection of claim 10 above), to determine a variation of a physical parameter along the measurement section according to the wavelengths of the radiation reflected by the second reference Bragg gratings (Grattan detects errors and corrects them which implies that the reference Bragg gratings, including the second Bragg gratings, are used to determine a variation of a physical parameter, such as temperature variations, along the measurement section; see Para. 41), and to determine the physical length of the measurement section according to the spectral width of the radiation reflected by the measurement Bragg grating (see Fig. 3-4 of Xia) and the variation of the physical parameter along the measurement section (an implied feature of the combination of Xia/Grattan resulting from the desire to remove environmental error such as temperature variations from the desired erosion measurement).
Regarding claim 15, Xia/Grattan discloses a method for determining a physical length of the measurement section of the erosion sensor according to claim 1 as discussed above, comprising:
measuring a spectral width of radiation reflected by the measurement Bragg grating (see Fig. 3-4 which show the reflection spectrum with varying amounts of erosion),
measuring a wavelength of radiation reflected by at least one of the one of more reference Bragg gratings (see Fig. 3-4 which show the reflection spectrum; note that the y-axis is measured in nanometers and represents wavelength), and
determining the physical length of the measurement section according to the spectral width of the radiation reflected by the measurement Bragg grating and the wavelength of the radiation reflected by the at least one reference Bragg grating (since the device is capable of obtaining a corresponding erosion depth value, it is interpreted as capable of determining a physical length of the measurement section; Xia relies upon spectral curves for this determination; see page 3, lines 1-2; see page 4, lines 6-7).
Claim(s) 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Xia in CN104482876A (hereinafter "Xia") in view of Grattan et al. in US 20050111793 A1 (hereinafter "Grattan") as applied to claim 1 above, and in further view of Mihailov in Opto-Mechanical Fiber Optic Sensors, Research, Technology, and Applications in Mechanical Sensing, Chapter 6, pages 137-174, 2018 (hereinafter "Mihailov").
Regarding claim 4, Xia/Grattan discloses the erosion sensor according to claim 1 as discussed above, but fails to teach that at least one Bragg grating is formed by a set of bubbles.
Mihailov discloses a device wherein at least one Bragg grating is formed by a set of bubbles (see Fig. 6.5(C) where the point by point femtosecond laser inscription is interpreted as a Bragg grating formed by a set of bubbles).
Accordingly, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have the Bragg grating formed with point by point femtosecond laser inscription bubbles as taught by Mihailov in the device of Xia/Grattan for the purpose of precisely controlling the placement of each bubble thereby achieving Bragg gratings with complete control over placement and even enhancing the thermal stability of the inscribed bubbles and thus the overall grating making it more suitable for higher temperature environments.
Conclusion
This prior art, made of record, but not relied upon, is considered pertinent to applicant’s disclosure since the following references have similar structure and/or use similar structure and/or similar optical elements to what is disclosed and/or claimed in the instant application:
US 20040222364 A1 measures position of cracks in concrete using a string of gratings.
WO 2020/049448 discloses an erosion sensor using Bragg gratings.
US 8571813 discloses a fiber-optic sensor system for determining surface wear.
US 20120201656 A1 discloses a wear-measuring device using Bragg gratings.
CA 2815788 A1 discloses teaches strings of grating sensors for monitoring health of concrete applications
CN 116698406 A discloses a wear-measuring device using Bragg gratings.
Reference U page 1 (Gillooly et al.) discloses a chirped fibre Bragg grating optical wear sensor.
Reference V page 1 (Enbang Li et al.) discloses a wear-measuring device using Bragg gratings.
Reference U page 2 (Rajabzadeh et al.) discloses a method of measuring the length of fiber Bragg grating sensors using the side-lobes of the reflection spectra.
Reference V page 2 (K. Markowski et al.) discloses a dual-core optical cable including one with a chirped fiber Bragg grating used as a sensor.
Reference W page 2 (Zheng et al.) discloses wear measurement based on the length variation of a sacrificial FBG.
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/DARBY M. THOMASON/
Examiner, Art Unit 2874
/UYEN CHAU N LE/Supervisory Patent Examiner, Art Unit 2874