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 .
Election/Restrictions
Applicant’s election without traverse of Group 2 and Species 4 directed to claims 204-208 in the reply filed on 8/15/2025 is acknowledged.
Claim 207 discloses a single de-matching layer positioned between the piezoelectric material (402) and the backing structure (408). However, the elected species 4 shown in Figure 17 has no further single de-matching layer shown therein. Hence, this claim is also directed to a non-elected species and is considered withdrawn.
Claim Rejections - 35 USC § 103
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) 204 is/are rejected under 35 U.S.C. 103 as being unpatentable over Tai (US 2013/0315035) and as evidenced by Tanoren (Examination of Film Thickness Dependence on Acoustic Impedance of Gold and Chromium Thin Films by Scanning Acoustic Microscopy, Int. J. Adv. Eng. Pure Sci. 2021, 33(3):505-510) and Isono (US 2020/0206778).Regarding Claim 204:In Figures 1-2, Tai discloses an ultrasonic transducer (16), comprising: a piezoelectric material (acoustic layer 48 formed from piezoelectric materials, see paragraph [0024]) having a front surface (top surface in Figure 2) and a back surface (bottom surface in Figure 2), the piezoelectric material (48) being configured to be in acoustic communication with a sample (body subjected to ultrasound scan, see paragraph [0002]); and a backing structure (50) positioned at the back surface of the piezoelectric material (as seen in Figure 2) and configured to reflect acoustic energy towards the front surface of the piezoelectric material (see paragraph [0026]), the backing structure comprising: a first dual layer de-matching backing (de-matching layer 50 comprises a first high impedance layer formed from a carbide compound material, for instance tungsten carbide, see paragraph [0027]. Furthermore, this carbide compound material is coated with an electrically conductive coating forming a second layer comprising a thin layer of chromium Cr and gold Au, see paragraph [0028]), the first dual layer de-matching backing comprising a first low acoustic impedance layer (electrically conductive coating formed from Cr of 0.1 µm thickness and Au of 0.2 µm thickness, see paragraph [0028]. Furthermore, Tanoren states the following in the abstract: “The acoustic impedance of Cr thin films were found as 1.901 ± 0.050 MRayl for 40 nm, 1.905 ± 0.045 MRayl for 80 nm, 1.943 ± 0.049 MRayl for 120 nm, 1.964 ± 0.049 MRayl for 160 nm and 1.987 ± 0.052 MRayl for 200 nm. The acoustic impedance of Au thin films were found as 1.725 ± 0.026 MRayl for 80 nm and 1.954 ± 0.047 MRayl for 200 nm. T.” This clearly indicates that the electrically conductive coating layer taught by Tai having a Cr layer of approximately 0.1 µm (100 nm) thickness would have an acoustic impedance of approximately 2 MRayl and the gold layer having a thickness of 0.2 µm (200 nm) would have an acoustic impedance of approximately 2 MRayl. This clearly indicates that this electrically conductive coating forms a low acoustic impedance layer henceforth referred to as L1) and a first high acoustic impedance layer (as stated in the paragraphs [0026]-[0027], the de-matching layer 50 can be formed from tungsten carbide and has an acoustic impedance in the range of approximately 40 MRayl to 120 MRayl. In paragraph [0039] Isono states that tungsten carbide has an acoustic impedance of about 90 MRayl. Henceforth referred to as L2).Tai does not explicitly disclose a second dual layer de-matching backing. However, in paragraph [0025], Tai discloses that there may be one or more dual layer de-matching backings (50) and further states that any number of de-matching backings may be used. It is further known in the art that the number of de-matching layers can be controlled in order to control the desired acoustic impedance properties of the ultrasound transducer. Hence, based on Tai’s teachings and common knowledge in the art, it would have been obvious to one of ordinary skill in the art, before the effective filing date, to have included a second dual de-matching backing (identical in structure to the first dual de-matching backing 50) as Tai teaches any number of de-matching backings can be provided, since doing so would be obvious to try and would yield predictable results such as providing the desired acoustic impedance properties in the ultrasound transducer based on the intended application (by controlling the number of provided de-matching backings) and improving the strength of the backing structure. After said modification was made, the added second dual layer de-matching backing would be connected to the first dual layer de-matching backing (envisioned as stacked layers by Tai in paragraph [0025]), the second dual layer de-matching backing comprising a second low acoustic impedance layer (L1 as described above) and a second high acoustic impedance layer (L2 as described above).
Claim(s) 205-206 and 208 is/are rejected under 35 U.S.C. 103 as being unpatentable over Tai (US 2013/0315035) as evidenced by Tanoren (Examination of Film Thickness Dependence on Acoustic Impedance of Gold and Chromium Thin Films by Scanning Acoustic Microscopy, Int. J. Adv. Eng. Pure Sci. 2021, 33(3):505-510), Isono (US 2020/0206778) and Lee et al. (herein Lee) (US 2008/0125658).
Regarding Claim 205:In Figures 1-2, Tai discloses the ultrasonic transducer (16), wherein: the ultrasonic transducer is operable at an operational frequency (known function of ultrasonic transducers and as mentioned in paragraph [0027]), the operational frequency being related to an operational wavelength (λo, operational frequency has a corresponding wavelength as is known in the art).Tai fails to explicitly disclose that the first and second low acoustic impedance layers (L1) and the first and second high acoustic impedance layers (L2) each have a corresponding thickness of about λo/4 thick or odd multiples of λo/4.However, in paragraph [0027], Tai states: “The dematching layer 50 may have any thickness, which may depend on the frequency of the ultrasound transducer 16.” Furthermore, Lee discloses a similar ultrasonic transducer (20) comprising a de-matching backing (88). In paragraph [0053] Lee states: “It may be noted that for the dematching layer 88 having an impedance of about 100 MRayls and a thickness of about one-fourth wavelength, the effective impedance seen to the rear of the acoustic layer 82 and towards the dematching layer 88 is about 24,000,000 MRayls for an air-backed transducer assembly where air is present to the rear of the dematching layer 88.” Hence, based on the evidence provided by Lee, it can be see that the thickness of the dematching backing can be controlled to approximately 1/4th of the wavelength to achieve a desired effective impedance. This indicates that the thickness of the de-matching backing is a controllable result-effective variable that can optimized to achieve the desired effective impedance. Hence, based on common knowledge in the art and the evidence provided by Lee, it would have been obvious to one or ordinary skill in the art, before the effective filing date of the claimed invention, to have modified the first and second low acoustic impedance layers (L1) and the first and second high acoustic impedance layers (L2) to each have a corresponding thickness of about λo/4 thick or odd multiples of λo/4 to achieve a desired effective impedance, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980).
Regarding Claim 205:Tai is silent regarding the resonant frequency of the piezoelectric material (48).However, it is extremely well known in the art that the resonant frequency of the piezoelectric material in an ultrasonic transducer can be selected based on the intended application and desired applied frequency ranges. For instance, in paragraph [0002], Isono states the following: “According to this structure, the piezoelectric layer made of a piezoelectric material such as piezoelectric ceramic is sandwiched between the materials lower in acoustic impedance than the piezoelectric material, so that both surfaces of the piezoelectric layer serve as open ends to excite half-wavelength resonance.” Therefore, based on common knowledge in the art and the evidence provided by Isono it can be seen that the resonant frequency of the piezoelectric material is an optimizable result-effective variable to achieve the predictable results of controlling the frequency output applied by the ultrasonic transducer.
Hence, based on common knowledge in the art and the evidence provided by Isono, it would have been obvious to one or ordinary skill in the art, before the effective filing date of the claimed invention, to have modified Tai’s piezoelectric material (48) tgo be half wave resonant at the operation frequency, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980).
Regarding Claim 208:In Figures 1-2, Tai discloses the ultrasonic transducer (16), wherein the backing structure (50) is further configured to spatially and temporally disperse unwanted acoustic reverberations in the backing structure (all impedance structures inherently spatially and temporally disposed at least some unwanted acoustic reverberations since they are designed to reflect acoustic energy over time and dampen reverberations, see for instance Tai’s paragraph [0026]).
Response to Arguments
Applicant's arguments filed 02/26/2026 have been fully considered but they are not persuasive. Applicant argues that Tai does not mention that the electrically conductive coating is acoustically engineered to contribute to the management of acoustic energy in the ultrasound transducer and so Tai as evidenced by Tanoren and Isono does not disclose a dual layer de-matching backing comprising a first low acoustic impedance layer and a first high acoustic impedance layer as claimed. However, the applicant has not explicitly argued why the inherent properties of the thin electrically conductive coating formed from Cr of 0.1 µm and Au of 0.2 µm thickness (see Tai’s paragraph [0028]) cannot serve as the low acoustic impedance layer in light of the evidence provided by Tanoren (see rejection above). Based on Tanoren’s evidence, it can be seen that the electrically conductive coating provided by Tai would function to provide a low acoustic impedance even if Tai does not explicitly mention it. In response to applicant's argument that Tai’s electrically conductive layer is not acoustically engineered, a recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim. In other words, based on Tai’s disclosed structure and the evidence provided by Tanoren and Isono as explained above in the rejection of claim 204, it can be seen that the structure disclosed by Tai is capable of inherently performing the same function as that which is claimed. The applicant has not sufficiently explained how the reasoning shown by the examiner to prove that Tai’s layers function in the claimed manner is flawed apart from some speculative statements. It is also noted that Tai teaches all the structure and so the argument that there is no motivation to modify is irrelevant.
In response to applicant's argument that Tai does not disclose any working principle and that Tai cannot control acoustic waves with the denoted layers, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985). In this case, Tai’s layers are capable of providing the same acoustic impedance characteristics as those claimed, especially in view of the cited evidence. In response to applicant's argument that the arrangement of the low and high impedance layers produces certain impedance characteristics, a recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim.
In response to applicant' s argument that there is no teaching, suggestion, or motivation to combine the references, the examiner recognizes that obviousness may be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988), In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992), and KSR International Co. v. Teleflex, Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007). In this case, based on the cited evidence and common knowledge in the art, the proposed modification is reasonable.
It is also noted that the terms such as high or low impedance are relatively broad. The applicant is arguing that the claimed structure of claim 204 would produces results such as those exemplified in Figure 13. However, Figure 13 discloses very specific results and materials that are not claimed in claim 204. Hence, without further amendments to claim 204 to establish specific numerical parameters for the claimed layers, this argument is not persuasive.
Due to these reasons, the rejection of claim 204 is not being withdrawn and the arguments are unpersuasive.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. See appended PTO-892 for relevant ultrasonic transducers and related structures.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DOMINICK L PLAKKOOTTAM whose telephone number is (571)270-7571. The examiner can normally be reached Monday - Friday 12 pm -8 pm ET.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Essama Omgba can be reached at 469-295-9278. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/DOMINICK L PLAKKOOTTAM/Primary Examiner, Art Unit 3746
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