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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 11/25/2025 has been entered. Claims 1-23 remain pending in the application.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 11/25/2025 has been considered by the examiner.
Response to Amendment
Claims 1-23 remain pending in the application in response to the applicant’s amendments to the rejections previously set forth in the Final Office Action mailed 08/27/2025.
The applicant submitted a terminal disclaimer over U.S. Patent No. 11,986,269 on 11/25/2025, and the terminal disclaimer is acknowledged and approved; thus, the Double Patenting Rejection is withdrawn.
Response to Arguments
Applicant’s arguments filed 11/25/2025 with respect to claim(s) 1 and 14 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Given the amendments to claim 1, reference to Zhang is being relied upon to teach dependent claim 13 more-consistently with the instant claim language, as shown below.
Given the amendments to claims 1 and 14, reference to Naimi is being relied upon to teach dependent claims 2-4 and 15-17 more-consistently with the instant claim language, as shown below.
Claim Rejections - 35 USC § 102
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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1 and 13-14 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by G. Zhang et al, “High Signal-to-Noise Ratio Contrast-Enhanced Photoacoustic Imaging using Acoustic Sub-Aperture Processing and Spatiotemporal Filtering”, 2019 IEEE International Ultrasonics Symposium (US), pp. 494-497, Oct. 2019, hereinafter referred to as Zhang.
Regarding claim 1, and similarly for claim 14, Zhang teaches a photoacoustic computed tomography method, comprising:
acquiring photoacoustic data recorded by one or more data acquisition devices of a photoacoustic computed tomography system, the photoacoustic data based at least in part on photoacoustic signals obtained by transducer elements of the photoacoustic computed tomography system (see pg. 495, col. 1, para. 3 – “The raw radiofrequency (RF) data was acquired over 10s at a 10 Hz pulse repetition frequency using the multispectral optoacoustic tomography (MSOT) system (inVision 256TF, iThera Medical) with a 256-element transducer covering a field of view of 270°, which is referred as MSOT 256.”);
applying location-based temporal filtering to the photoacoustic data acquired, wherein applying the location-based temporal filtering is on a sub-domain by sub-domain basis for a plurality of imaging sub-domains, the plurality of imaging sub-domains when aggregated forming an entire two-dimensional imaging domain (see pg. 495, col. 1, para. 5 to pg. 495, col. 2, para. 1 – “… RF data collected from 256 channels was equally split into two groups in an alternating pattern [location-based]. Then each set of data extracted from 128 channels was beamformed individually to reconstruct an image for one sub-aperture and two image data sets were obtained [imaging sub-domains]. Singular value decomposition processing [temporal filtering] was applied to each image data set subsequently to remove the clutter signals by rejecting the first several singular vectors that are related to tissue [filtering is on a sub-domain by sub-domain basis]. Next, these two sets of SVD-filtered images were cross-correlated over the 100 frames to generate the final ASAP SVD-filtered image [imaging sub-domains when aggregated forming an entire two-dimensional imaging domain].”); and
reconstructing one or more photoacoustic images from the filtered photoacoustic data (pg. 495, col. 2, para. 1 – “Next, these two sets of SVD-filtered images [filtered photoacoustic data] were cross-correlated [reconstructing] over the 100 frames to generate the final ASAP SVD-filtered image [photoacoustic image].”).
Furthermore, regarding claim 13, Zhang further teaches wherein universal back projection is used to reconstruct the one or more photoacoustic images (see pg. 495, col. 1, para. 3 – “Photoacoustic images were then reconstructed by extracting and beamforming these RF data using a customized back-projection algorithm in Matlab.”).
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.
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.
Claims 2-4 and 15-17 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang in view of Naimi et al. (US 20110243409 A1, published October 6, 2011), hereinafter referred to as Naimi.
Regarding claims 2 and 15, Zhang teaches all of the elements disclosed in claim 1 and 14 above.
Zhang teaches applying location-based temporal filtering to photoacoustic data, but does not explicitly teach applying spatial interpolation after applying the location-based temporal filtering.
Whereas, Naimi, in an analogous field of endeavor, teaches applying spatial interpolation after applying the location-based temporal filtering (Fig. 14; see para. 0196 – “The method begins at 310 and continues to 320 at which the method performs convolution of intensity data representing the thermal image (e.g., intensity data, variance, changes over time, etc.) with a predetermined vessel shapes filter thereby providing filtered data.”; see para. 0226 – “At 350 the method applies an interpolation procedure for generating contours between at least a few of the local intensity extrema.”).
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified applying location-based temporal filtering to photoacoustic data, as disclosed in Zhang, by also applying spatial interpolation after applying the location-based temporal filtering, as disclosed in Naimi. One of ordinary skill in the art would have been motivated to make this modification in order to generate contours between at least a few of the local intensity extrema in the image, and identify the contours as blood vessels in the image, as taught in Naimi (see para. 0231).
Furthermore, regarding claims 3 and 16, Naimi further teaches wherein the spatial interpolation is performed on the sub-domain by sub-domain basis for the plurality of imaging sub-domains (Fig. 14; see para. 0196 – “The method begins at 310 and continues to 320 at which the method performs convolution of intensity data representing the thermal image (e.g., intensity data, variance, changes over time, etc.) with a predetermined vessel shapes filter thereby providing filtered data.”; see para. 0226 – “At 350 the method applies an interpolation procedure for generating contours between at least a few of the local intensity extrema.”).
Furthermore, regarding claims 4 and 17, Naimi further teaches wherein applying location-based temporal filtering mitigates aliasing prior to the spatial interpolation (Fig. 14; see para. 0196 – “The method begins at 310 and continues to 320 at which the method performs convolution of intensity data representing the thermal image (e.g., intensity data, variance, changes over time, etc.) with a predetermined vessel shapes filter thereby providing filtered data.”; see para. 0226 – “At 350 the method applies an interpolation procedure for generating contours between at least a few of the local intensity extrema.”).
The motivation for claims 3-4 and 16-17 was shown previously in claims 2 and 15.
Claims 5-6, 8-9, 18-19, and 21-22 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang in view of H. Huang et al, “An adaptive filtered back-projection for photoacoustic image reconstruction”, Medical Physics, vol. 42, no. 5, pp. 2169-2178, May 2015, hereinafter referred to as Huang.
Regarding claims 5 and 18, Zhang teaches all of the elements disclosed in claims 1 and 14 above.
Zhang teaches applying location-based temporal filtering, but does not explicitly teach pplying one or more lowpass filters associated with the upper cutoff frequency to each imaging sub-domain.
Whereas, Huang, in the same field of endeavor, teaches wherein applying the location-based temporal filtering comprises: determining an upper cutoff frequency for each imaging sub-domain; and applying one or more lowpass filters associated with the upper cutoff frequency (see pg. 2171, col. 1, para. 3 — “The weighting function has a series of singular points when ckt = +(n+1/2), therefore, in Fourier domain for a sampling period (T), one should, naturally, choose the cutoff frequency fcutoff using ckt < π/2 or π fcutoffT < π/2 to avoid singular points. This allows us to obtain an objective upper limit for setting the cutoff frequency fcutoff for a low pass filter. We obtain that fcutoff < (fsampling/4), where fsampling is the sampling rate.”).
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified applying location-based temporal filtering, as disclosed in Zhang, by applying one or more lowpass filters associated with the upper cutoff frequency to each imaging sub-domain, as disclosed in Huang. One of ordinary skill in the art would have been motivated to make this modification in order to obtain a sharper image, as taught in Huang (see pg. 2176, col. 2, para. 2).
Furthermore, regarding claims 6 and 19, Huang further teaches wherein
the one or more lowpass filters associated with the upper cutoff frequency comprise a plurality of lowpass filters each having a different cutoff frequency less than the upper cutoff frequency, and wherein applying the location-based temporal filtering comprises: applying the plurality of lowpass filters to the photoacoustic data (see pg. 2172, col. 2, para. 3 — “Based on the discussion in Sec. 2, our cutoff frequency will be set adaptively; in this case, the cutoff frequency for the low-pass filter is set to 5.0 MHz.”); and
temporal recentering the filtered photoacoustic data for each imaging subdomain of the plurality of imaging sub-domains based on distances between the transducer elements and a center of each imaging subdomain (see pg. 2172, col. 1, para. 5- “For a uniform sample spherical absorber, one can adopt the approximate model suggested in p(r,t) = ... [Equation (18)] ... where AO is a constant, U(a—|R-ct|) is Heaviside function, a is radius of sphere, and R denotes the distance between the center of absorber and detector.”).
Furthermore, regarding claims 8 and 21, Huang further teaches wherein the upper cutoff frequency for a given imaging sub-domain is determined based on locations of the transducer elements, a center of the given imaging sub-domain, and locations of points on a boundary of the given imaging sub-domain (see pg. 2174, col. 1, para. 2 — “The second measurement configuration is an arc-shaped detector array composed of 50-point detectors, evenly spaced over a span of 160° , with a radius of 65 mm. The detector array rotates in 2° steps over 360°, giving 9000 (50x180) detection points (see Fig. 3).”).
Furthermore, regarding claims 9 and 22, Huang further teaches wherein a point source is outside of an imaging sub-domain, and wherein the upper cutoff frequency for the imaging sub-domain is further based on locations of the transducer elements, a center of the imaging sub-domain, and location of the point source (see pg. 2174, col. 1, para. 2—“The second measurement configuration is an arc-shaped detector array composed of 50- point detectors, evenly spaced over a span of 160°, with a radius of 65mm. The detector array rotates in 2° steps over 360°, giving 9000 (50x180) detection points (see Fig. 3).”).
The motivation for claims 6, 8-9, 19, and 21-22 was shown previously in claims 5 and 18.
Claims 7 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang in view of Huang, as applied to claim 5 above, and in further view of Irisawa et al. (US 20140257079 A1, published September 11, 2014), hereinafter referred to as Irisawa.
Regarding claims 7 and 20, Zhang in view of Huang teaches all of the elements disclosed in claim 5 and 18 above.
Zhang in view of Huang teaches selecting an upper cutoff frequency, but does not explicitly teach where the upper cutoff frequency is selected such that a Nyquist criterion is satisfied for each imaging sub-domain.
Whereas, Irisawa, in the same field of endeavor, teaches wherein the upper cutoff frequency is selected such that a Nyquist criterion is satisfied for each imaging sub-domain (see para. 0091 — “The resampling means 46 achieves the upsampling by, for example, adding zero between sample points of the photoacoustic signal sampled at a low sampling rate and applying a low-pass filter with a cut off frequency equal to a Nyquist frequency before the upsampling.”).
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified selecting an upper cutoff frequency, as disclosed in Zhang in view of Huang, by having the upper cutoff frequency selected such that a Nyquist criterion is satisfied for each sub-domain, as disclosed in Irisawa. One of ordinary skill in the art would have been motivated to make this modification in order to fill a difference of the band between the signals in the frequency domain, in place of the time domain, accurate deconvolution of the light pulse differential term can be achieved while using low speed sampling for the detection and the reconstruction of the photoacoustic signal, as taught in Irisawa (see para. 0103).
Allowable Subject Matter
As allowable subject matter has been indicated, applicant's reply must either comply with all formal requirements or specifically traverse each requirement not complied with (see 102 and 103 rejections above). See 37 CFR 1.111(b) and MPEP § 707.07(a).
The following is a statement of reasons for the indication of allowable subject matter:
For claim 10, and similarly for claim 23, no prior art was found that teaches the combination of limitations:
performing an initial reconstruction without anti-aliasing to generate a reconstructed image;
obtaining a set of point source candidates based on the reconstructed image, wherein the general source is different than the set of point source candidates;
randomly selecting one point source in each square of the set of squares as a point source;
repeating the random selection of one point source in each square and applying the location- based temporally filtering for each imaging sub-domain at least one other time to obtain multiple images; and
generating a final reconstructed image based on an average of the multiple images, as disclosed in the applicant’s specification (see para. 0119-0130) and Fig. 7, without hindsight reasoning.
Any combination of the prior art of record does not explicitly teach this limitation as the limitation in combination with all of the other elements of the claim is not obvious or similar.
The closest prior art found to teach the combination of limitations is S. Arridge et al, “Accelerated High-Resolution Photoacoustic Tomography via Compressed Sensing”, Physics in Medicine and Biology, vol. 61, no. 24, pp. 1-34, Dec. 2016, which teaches sampling the photoacoustic field at a smaller number of randomly chosen points for image reconstruction (Fig. 4; see pg. 5, para. 2), but does not explicitly teach repeating the random selection of one point source in each square and applying the location-based temporally filtering for each sub-domain at least one other time to obtain multiple images, and generating a final reconstructed image based on an average of the multiple images without hindsight reasoning.
Claims 11-12 are dependent of claim 10, and therefore considered allowable subject matter as well.
Conclusion
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/Nyrobi Celestine/Examiner, Art Unit 3798