Prosecution Insights
Last updated: September 17, 2026
Application No. 18/692,732

USE OF FLUORESCENT OR VISIBLE TRACERS TO MONITOR NUTRIENT CONCENTRATIONS IN SOLUTION

Non-Final OA §103§112
Filed
Mar 15, 2024
Priority
Sep 17, 2021 — provisional 63/245,311 +1 more
Examiner
FISHER, BRITTANY I
Art Unit
Tech Center
Assignee
Fehr Solutions LLC
OA Round
1 (Non-Final)
84%
Grant Probability
Favorable
1-2
OA Rounds
3m
Est. Remaining
97%
With Interview

Examiner Intelligence

Grants 84% — above average
84%
Career Allowance Rate
459 granted / 543 resolved
+24.5% vs TC avg
Moderate +12% lift
Without
With
+12.3%
Interview Lift
resolved cases with interview
Typical timeline
2y 9m
Avg Prosecution
35 currently pending
Career history
572
Total Applications
across all art units

Statute-Specific Performance

§101
1.3%
-38.7% vs TC avg
§103
45.1%
+5.1% vs TC avg
§102
27.3%
-12.7% vs TC avg
§112
21.2%
-18.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 543 resolved cases

Office Action

§103 §112
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 . Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 1-14 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. With respect to claim 1, it is unclear if the second recitation of “inert fluorescent tracer” in the first line of clause b is intended to the same as the inert fluorescent tracer recited in clause a, or if applicant is intending for the second recitation to be directed to a separate and/or different inert fluorescent tracer. Is the inert fluorescent tracer recited in clause a now being incorporated into the recited two or more mixtures, or does the inert fluorescent tracer is the first clause separate from that which is recited in clause b? Clarification is requested. Claims 2-14 are ultimately dependent upon claim 1, and thus, inherit the same deficiencies. Claim 6 recites the limitation "the Horticulture methods" in line 1. There is insufficient antecedent basis for this limitation in the claim. 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. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. Claim(s) 1-4, 6-10, and 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Brooke et al (US 9,073,798 B1) in view of Rao et al (10,765,999 B2). With respect to claim 1 Brooke discloses a method to optimize horticulture of growing plants ("The present compositions and method may broadly be applicable to any plant growth medium, but may be particularly suitable for hydroponics ... " – See Col. 4, Iines 26-28) by determining whether the desired amount of at least two nutrient products is present in water which is used to deliver nutrients to growing plants (See Fig. 2); comprising the steps of: adding a known amount of an inert fluorescent tracer to a known amount of a nutrient, wherein said nutrient is useful to provide nutrition to growing plants ("mixing a first coloring agent into a first pre-formulated fertilizer having a first nutrient profile" - Col. 4, Iines 33-35; claim 4, and Col. 17, Iines 18-20 for discussion of fluorescent markers); adding at least two or more mixtures of inert fluorescent tracer and nutrient ("mixing a second coloring agent into a second pre-formulated fertilizer having a second nutrient profile distinct from the first nutrient profile"- See Col. 4, Iines 35-37) to water to create a nutrient liquid; wherein the two or more mixtures have different fluorescent tracers and a different nutrient (See Fig. 4 and Col. 11, Iines 18-47); using a light-sensitive device ("color light sensor 450 such as a charge­coupled device (CCD) camera may be in communication with the computing device 320 to provide feedback on the resulting hue of the concentration blend” – See Col. 11, lines 34-37) to determine the concentration of two or more inert fluorescent tracers in the water and using the concentration of two or more inert fluorescent tracers to calculate the amount of each nutrient present in the water (via computing device 320; See Col. 11, lines 18-47); adjusting the amount of nutrient present in the water when at least one of the fluorescent signals of at least one of the inert fluorescent tracers indicates either too much or too little of the nutrient matched with that inert fluorescent tracer is present (See steps 217 and 219 of Fig. 2; Col. 10, Iines 43-47 - "If the resultant hue is not a match with the reference hue (test 217), e.g., by a color-based comparison...the resultant hue may be adjusted (step 219) by adding portions of one or more of the pre-formulated colorized fertilizers"); and applying the nutrient liquid to growing plants (See step 229 of Fig. 2). Brooke fails to disclose the use of two or more fluorometers (i.e. light-sensitive devices). Rao teaches a method for controlling treatment of an industrial water system (See abstract), wherein an alternative approach to monitor the amount of active added to tank 106 is based on monitoring the direct fluorescence of the active or an inert fluorophore that is mixed with an active at a known proportional amount (See Col. 10, lines 12-15). To monitor multiple actives by fluorescence at different wavelengths, a dispersive or non-dispersive fluorometer can be used. When using a non-dispersive fluorometer, dedicated excitation sources and detector assemblies with appropriate bandpass filter are needed for each wavelength range detected. Using a dispersive system simplifies the number of detectors needed by monitoring the emitted fluorescence of each species on an array detector. To minimize interference from multiple excitation sources and fluorescence from actives or inert dyes, phase sensitive detection techniques can be applied as well as using bandpass filters. Finally, monitoring fluorescence from highly concentrated actives can be problematic due to self-absorption and quenching. In this case, reflectance fluorescence monitoring is the preferred choice with the excitation light incident on the medium with the emitted fluorescence collected in the reflectance mode. For example, a bifurcated fiber can be used to deliver the excitation light through one leg of the fiber and collect emitted fluorescence through the other leg directed to either a dispersive or non-dispersive detection system (See Col. 10, lines 37-57). It would have been obvious to one of ordinary skill in the at before the effective filing date of the claimed invention to provide an alternative design possibility of providing single-wavelength devices, such as taught by Rao, as the light-sensitive device of Brooke in order allow for the detection of fluorescent tracers of varying wavelengths (See Col. 10, lines 37-57 of Rao). Additionally, in the event that it is found that Brooke and Rao fails to explicitly teach the incorporation of multiple fluorometers, it should be noted that the courts have held In re Harza, 274 F.2d 669, 124 USPQ 378 (CCPA 1960) that even if a reference does not teach a plurality of a feature, a mere duplication of parts has no patentable significance unless a new and unexpected result is produced. With respect to claims 2 and 3 Brooke fails to disclosure or teach the specifics of the fluorescent material being PTSA. Rao teaches monitoring and controlling the amount of active added to the holding tank by monitoring fluorescence of a secondary fluorophore component, e.g., PTSA, blended with the concentrated active. The fluorescence from the PTSA monitored by fluorometer 116 (FIG. 1) provides a metric for the active concentration, since the proportion of PTSA to active is known. For example, to construct the additive package in Table 1, HEDP traced with PTSA, can be added first to the holding tank with additional dilution water to set a baseline fluorescent signal count representing a HEDP concentration of the target 11% value for a completed additive package. Controlling the concentration of the subsequent actives is then made by selectively adding or not adding PTSA to concentrated actives. In this case, if the second active added is THSP with no PTSA then the signal measured using the fluorometer tuned for PTSA monitoring will change. The amount of attenuation or gain depending on the concentration level is directly proportional to the amount of THSP added. Addition of the third active, TT, with PTSA added would then result in fluorescence signal increasing a proportional amount. By selectively including PTSA with specific actives provides a means to increase the measurement sensitivity to control the blend concentration (See Col. 12, line 50 – Col. 13, line 6). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate PTSA, as taught by Rao, as the inert fluorescence material of Brooke, in order to increase the measurement sensitivity of the blend concentration of nutrient products (See Col. 12, line 50 – Col. 13, line 6 of Rao). With respect to claim 4 the combination of Brooke and Rao teaches that the nutrients present in the nutrient liquid include nitrogen, phosphorous, and potassium (See Col. 2, lines 20-28 of Brooke). With respect to claim 6 the combination of Brooke and Rao teaches that the horticulture methods are use in hydroponics (See Col. 4, lines 23-28 of Brooke). With respect to claim 7 the combination of Brooke and Rao teaches that the growing plants are selected from the group consisting of fruits, vegetables, tobacco, Cannabis, Hemp, and trees (Brooke: See Col. 30, lines 2-5 for discussion of creating formulations that are useful for optimizing nutrients for plants such as flower, vegetables, and fruits; Col. 32, lines 34-35 contemplate optimum nutrients for cannabis plants). With respect to claim 8 the combination of Brooke and Rao teaches that the growing plants are selected from the group consisting of fruits (Brooke: See Col. 30, lines 2-5 for discussion of creating formulations that are useful for optimizing nutrients for plants such as flower, vegetables, and fruits). With respect to claim 9 the combination of Brooke and Rao teaches that the growing plants are selected from the group consisting of vegetables (Brooke: See Col. 30, lines 2-5 for discussion of creating formulations that are useful for optimizing nutrients for plants such as flower, vegetables, and fruits). With respect to claim 10 the combination of Brooke and Rao teaches that the growing plants are selected from the group consisting of tobacco, Cannabis, and Hemp plants (Brooke: See Col. 32, lines 34-35 contemplate optimum nutrients for cannabis plants). With respect to claim 12 the combination of Brooke and Rao teaches that the growing plants are selected from the group consisting of tobacco, Cannabis, and Hemp plants (Brooke: See Col. 32, lines 34-35 contemplate optimum nutrients for cannabis plants). Claim(s) 11, 13, and 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Brooke et al (US 9,073,798 B1) and Rao et al (10,765,999 B2) in view of Stroock et al (US 2021/0116374 A1). Refer above for the combined teaching of Brooke and Rao. With respect to claims 11, 13, and 14, the combination of Brooke and Rao fails to teach that the growing plants are tobacco (claim 11), hemp (claim 13), or trees (claim 14). Stroock teaches methods and systems useful for determining the response of a substance (including a plant) to water potential. Dispersible biosensors can be useful in a variety of contexts (See Para. 0038). in plants, biosensors may be functionalized with appropriate moieties to detect concentration of abscisic acid or another chemical secreted by plants with change in water potential. A similar response of cells to water potential could be measured by functionalizing biosensors and detecting optical signals in a multiplexed manner (See Para. 0039). In one embodiment, the substance is a plant. In at least one embodiment, the biosensor allows for remote measurement of ψleaf at the level of individual plants. The methods and systems described herein can be used for a wide variety of plants or their seeds. Suitable plants include dicots and monocots. Suitable plants include, for example, crop plants, such as, but not limited to, cereal crops, vegetable crops, fruit crops, flower crops, and grass crops. For example, suitable plants include, but are not limited to, industrial hemp and guayule, as well as agronomic row or other field crops including buckwheat, beans (soybean, snap, dry), corn (grain, seed, sweet corn, silage, popcorn, high oil), cotton, canola, peas (dry, succulent), peanuts, rice, safflower, and sunflower; alfalfa hay and forage crops including alfalfa, clover, vetch, and trefoil; berries and small fruits including blackberries, blueberries, currants, elderberries, gooseberries, huckleberries, loganberries, raspberries, strawberries, and grapes; bulb crops including garlic, leeks, onions, shallots, and ornamental bulbs; citrus fruits including citrus hybrids, grapefruit, kumquat, limes, lemons, oranges, and pummelos; cucurbit vegetables including cucumbers, melons, gourds, pumpkins, squash, and flowers; bedding plants and ornamentals including Arabidopsis thaliana, Saintpaulia, petunia, pelargonium, poinsettia, chrysanthemum, carnation, and zinnia; fruiting vegetables including eggplant, sweet and hot peppers, tomatillos, tomatoes, herbs, spices, and mints; hydroponic crops including cucumbers, tomatoes, and lettuce; herbs and spices; leafy vegetables and cole crops including arugula, celery, chervil, endive, fennel, lettuce (head and leaf), parsley, radicchio, rhubarb, spinach, Swiss chard, broccoli, Brussels sprouts, cabbage, cauliflower, collards, kale, kohlrabi, mustard greens, and asparagus; legume vegetable and field crops including snap and dry beans, lentils, succulent and dry peas, peanuts, and soybeans; pome fruit including pears and quince; crops including beets, sugarbeets, red beets, carrots, celeriac, chicory, horseradish, parsnip, radish, rutabaga, salsify, turnips, sugarcane, zucchini, apple, pineapple, and tobacco; shadehouse and other nursery crops including deciduous trees (maple, oak), ornamentals, grapes, citrus, and pine; small grains including barley, rye, wheat, sorghum, and millet; stone fruits including apricots, cherries, nectarines, peaches, plums, and prunes (See Para. 0040). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to allow for tobacco, hemp, and various trees to be included in the listing of suitable plants being worked upon, as taught by Strook, as the methods have utility in any kind of agriculture, horticultural, and/or forestry practice (See Para. 0040 of Strook). Allowable Subject Matter Claim 5 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims. The following is a statement of reasons for the indication of allowable subject matter: The closest cited prior art of reference fails to disclose that the inert fluorescent tracer for nitrogen is PTSA, the inert fluorescent tracer for phosphorous is NDSA, and the inert fluorescent tracer for potassium is Rhodamine. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to BRITTANY I FISHER whose telephone number is (469)295-9182. The examiner can normally be reached IFP. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, James Lin can be reached at (571) 272-8902. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /BRITTANY I FISHER/Examiner, Art Unit 1796 August 22, 2026
Read full office action

Prosecution Timeline

Mar 15, 2024
Application Filed
Aug 26, 2026
Non-Final Rejection mailed — §103, §112 (current)

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Prosecution Projections

1-2
Expected OA Rounds
84%
Grant Probability
97%
With Interview (+12.3%)
2y 9m (~3m remaining)
Median Time to Grant
Low
PTA Risk
Based on 543 resolved cases by this examiner. Grant probability derived from career allowance rate.

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