Prosecution Insights
Last updated: April 19, 2026
Application No. 18/460,985

CROSS-DOMAIN UNROLLING-BASED IMAGING PHOTOPLETHYSMOGRAPHY SYSTEMS AND METHODS FOR ESTIMATING VITAL SIGNS

Final Rejection §101
Filed
Sep 05, 2023
Examiner
MOHAMMED, SHAHDEEP
Art Unit
3797
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Mitsubishi Electric Research Laboratories Inc.
OA Round
2 (Final)
51%
Grant Probability
Moderate
3-4
OA Rounds
4y 10m
To Grant
99%
With Interview

Examiner Intelligence

Grants 51% of resolved cases
51%
Career Allow Rate
234 granted / 462 resolved
-19.4% vs TC avg
Strong +57% interview lift
Without
With
+56.7%
Interview Lift
resolved cases with interview
Typical timeline
4y 10m
Avg Prosecution
59 currently pending
Career history
521
Total Applications
across all art units

Statute-Specific Performance

§101
7.3%
-32.7% vs TC avg
§103
45.7%
+5.7% vs TC avg
§102
11.8%
-28.2% vs TC avg
§112
27.9%
-12.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 462 resolved cases

Office Action

§101
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 § 101 35 U.S.C. 101 reads as follows: Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title. Claims 1-20 are rejected under 35 U.S.C. 101 because the claimed invention is directed to an abstract idea without significantly more. The claims recite an abstract idea as discussed below. This abstract idea is not integrated into a practical application for the reasons discussed below. The claims do not include additional elements that are sufficient to amount to significantly more than the judicial exception for the reasons discussed below. Step 1 of the 2019 Guidance requires the examiner to determine if the claims are to one of the statutory categories of invention. Applied to the present application, the claims belong to one of the statutory classes of a process or product as a computer implemented method or a computer system/product. Step 2A of the 2019 Guidance is divided into two Prongs. Prong 1 requires the examiner to determine if the claims recite an abstract idea, and further requires that the abstract idea belong to one of three enumerated groupings: mathematical concepts, mental processes, and certain methods of organizing human activity. Regarding claim 1, the claim is directed to a remote photoplethysmography system for estimating a vital sign signal of a subject. The claim limitations of “execute a cross-domain unrolling optimization iteratively minimizing a difference between the received iPPG signals and reconstructed iPPG signals, wherein the reconstructed iPPG signals have frequency coefficients determined in a frequency domain and transformed into the time domain of the received iPPG signals before computation of the difference between the received iPPG signals and the reconstructed iPPG signals, and wherein the reconstructed iPPG signals are obtained as output of an iPPG neural network trained in the frequency domain with machine learning to enforce a learned structure on the frequency coefficients of the reconstructed iPPG signals; determine the vital sign signal of the subject from the frequency coefficients of the reconstructed iPPG signals upon reaching a termination condition of the cross-domain unrolling optimization” are directed to an abstract because the claim limitations can be performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen paper. Therefore, the cited limitations above, under their broadest reasonable interpretation, cover performance in the mind but for the recitation of generic computer components (i.e., the “processor” and “memory). Other than the processor and memory (which is represented simply as a part of a basic computer system), nothing identified in the claim is precluded from being practically performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen and paper. See MPEP § 2106.04(a)(2)(III)(B). Intellectual Ventures LLC v. Symantec Corp., 838 F.3d 1307, 1318 (Fed. Cir. 2016) established that mental processes encompass acts which, absent anything beyond generic computer components, may be “performed by a human, mentally or with pen and paper.” Intellectual Ventures additionally established that if a claim, under its broadest reasonable interpretation, covers performance in the mind but for the recitation of generic computer components, then it is still in the mental processes category of abstract ideas unless the claim cannot be practically performed in the mind. The judicial exception is not integrated into a “practical application” as defined by the Subject Matter Eligibility Analysis documented in Federal Register 84(4), issued on 07 January 2019 and since documented in MPEP § 2106. While the claim recites that a “a processor” and “memory” that performs the limitations encompassing mental processes and mathematical concepts, this simply represents implementing the abstract ideas with a computer. The additional limitations in relation to the computer, computer product, or computer system does not offer a meaningful limitation beyond generally linking the use of the method to a computer (see ALICE CORP. v. CLS BANK INT’L 573 U. S. ____ (2014)). The claim does not recite a particular machine applying or being used by the abstract idea. See also subsection I of the cited section and MPEP § 2106.05(f) which indicates that instructions to implement the abstract idea on a computer or that “using a computer as a tool to perform the abstract idea” are not sufficient to integrate a judicial exception into a “practical application” as interpreted by the courts. Furthermore, the claim does not include additional elements which are sufficient to amount to significantly more than the abstract idea. As discussed above, the additional elements of a generic computer components (“processors” and “memory”) to execute the abstract ideas and does not add significantly more that the abstract idea because since the one or more processors are merely a generic computer component with the computer being used as a tool for performing the abstract idea. Furthermore, the claim limitation of “receive a sequence of imaging photoplethysmography (IPPG) signals measured from different regions of a skin of the subject in a time domain” is directed to extra solution activity of gathering data and does not include additional elements which are sufficient to amount to significantly more than the abstract idea. Furthermore, the claims limitation “output the vital sign signal corresponding to the reconstructed IPPG signals via an output interface” does not add significantly more than the abstract idea because merely outputting result is directed to extra solution activity. In consideration of each of the relevant factors and the claim elements both individually and in combination, claim 1 is directed to an abstract ideas without sufficient integration into a practical application and without significantly more. Regarding claim 2, the clam further recited claim limitation that (i.e., estimating noise) is directed to an abstract because the claim limitations can be performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen paper. Regarding claim 3, the clam further recites claim limitation is directed to an abstract because the claim limitations can be performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen paper. Regarding claim 4, the clam further recites claim limitation is directed to an abstract because the claim limitations can be performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen paper. Regarding claim 5, the clam further recites claim limitation is directed to an abstract because the claim limitations can be performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen paper. Regarding claim 6, the clam further recites claim limitation is directed to an abstract because the claim limitations can be performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen paper. Regarding claim 7, the clam further recites claim limitation is directed to an abstract because the claim limitations can be performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen paper. Regarding claim 8, the clam further recites claim limitation is directed to an abstract because the claim limitations can be performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen paper. Regarding claim 9, the clam further recites claim limitation is directed to an abstract because the claim limitations can be performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen paper. Regarding claim 10-14, the clam further recites claim limitation is directed to an abstract because the claim limitations can be performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen paper. Regarding claim 15, the claim recites additional element of a generic computer components (“controller”) to execute the abstract ideas and does not add significantly more that the abstract idea because since the one or more processors are merely a generic computer component with the computer being used as a tool for performing the abstract idea. Furthermore, the claim limitation of “receive the vital sign of the subject” is directed to extra solution activity of gathering data and does not include additional elements which are sufficient to amount to significantly more than the abstract idea. Regarding claim 16, the claim is directed to a computer-implemented method for estimating a vital signal of a subject. The claim limitations of executing a cross-domain unrolling optimization iteratively minimizing a difference between the received iPPG signals and reconstructed iPPG signals, wherein the reconstructed iPPG signals have frequency coefficients determined in a frequency domain and transformed into the time domain of the received iPPG signals before computation of the difference between the received iPPG signals and the reconstructed iPPG signals, and wherein the reconstructed iPPG signals are obtained as output of an iPPG neural network trained in the frequency domain with machine learning to enforce a learned structure on the frequency coefficients of the reconstructed iPPG signals; determining the vital sign signal of the subject from the frequency coefficients of the reconstructed iPPG signals upon reaching a termination condition of the cross-domain unrolling optimization” are directed to an abstract because the claim limitations can be performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen paper. Therefore, the cited limitations above, under their broadest reasonable interpretation, cover performance in the mind, and nothing identified in the claim is precluded from being practically performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen and paper. See MPEP § 2106.04(a)(2)(III)(B). Intellectual Ventures LLC v. Symantec Corp., 838 F.3d 1307, 1318 (Fed. Cir. 2016) established that mental processes encompass acts which, absent anything beyond generic computer components, may be “performed by a human, mentally or with pen and paper.” Intellectual Ventures additionally established that if a claim, under its broadest reasonable interpretation, covers performance in the mind but for the recitation of generic computer components, then it is still in the mental processes category of abstract ideas unless the claim cannot be practically performed in the mind. The judicial exception is not integrated into a “practical application” as defined by the Subject Matter Eligibility Analysis documented in Federal Register 84(4), issued on 07 January 2019 and since documented in MPEP § 2106. While the claim recites that a “one or more processor” that performs the limitations encompassing mental processes, this simply represents implementing the abstract ideas with a computer. The additional limitations in relation to the computer, computer product, or computer system does not offer a meaningful limitation beyond generally linking the use of the method to a computer (see ALICE CORP. v. CLS BANK INT’L 573 U. S. ____ (2014)). The claim does not recite a particular machine applying or being used by the abstract idea. See also subsection I of the cited section and MPEP § 2106.05(f) which indicates that instructions to implement the abstract idea on a computer or that “using a computer as a tool to perform the abstract idea” are not sufficient to integrate a judicial exception into a “practical application” as interpreted by the courts. Furthermore, the claim does not include additional elements which are sufficient to amount to significantly more than the abstract idea. The claims limitation “outputting the vital sign signal corresponding to the reconstructed IPPG signals via an output interface” does not add significantly more than the abstract idea because merely outputting result is directed to extra solution activity. In consideration of each of the relevant factors and the claim elements both individually and in combination, claim 16 is directed to an abstract ideas without sufficient integration into a practical application and without significantly more. Regarding claim 17-18, the clam further recited claim limitation that (i.e., estimating noiuse) is directed to an abstract because the claim limitations can be performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen paper. Regarding claim 19, the clam further recites claim limitation is directed to an abstract because the claim limitations can be performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen paper. Regarding claim 20, the claim is directed to a non-transitory computer readable medium having a stored thereon computer-executable instructions which when executed by a computer, case the computer to perform a method for estimating a vital sign signal of a subject. The claim limitations of executing a cross-domain unrolling optimization iteratively minimizing a difference between the received iPPG signals and reconstructed iPPG signals, wherein the reconstructed iPPG signals have frequency coefficients determined in a frequency domain and transformed into the time domain of the received iPPG signals before computation of the difference between the received iPPG signals and the reconstructed iPPG signals, and wherein the reconstructed iPPG signals are obtained as output of an iPPG neural network trained in the frequency domain with machine learning to enforce a learned structure on the frequency coefficients of the reconstructed iPPG signals; determining the vital sign signal of the subject from the frequency coefficients of the reconstructed iPPG signals upon reaching a termination condition of the cross-domain unrolling optimization” are directed to an abstract because the claim limitations can be performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen paper. Therefore, the cited limitations above, under their broadest reasonable interpretation, cover performance in the mind but for the recitation of generic computer components (i.e., the computer). Other than the computer (which is represented simply as a part of a basic computer system), nothing identified in the claim is precluded from being practically performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen and paper. See MPEP § 2106.04(a)(2)(III)(B). Intellectual Ventures LLC v. Symantec Corp., 838 F.3d 1307, 1318 (Fed. Cir. 2016) established that mental processes encompass acts which, absent anything beyond generic computer components, may be “performed by a human, mentally or with pen and paper.” Intellectual Ventures additionally established that if a claim, under its broadest reasonable interpretation, covers performance in the mind but for the recitation of generic computer components, then it is still in the mental processes category of abstract ideas unless the claim cannot be practically performed in the mind. The judicial exception is not integrated into a “practical application” as defined by the Subject Matter Eligibility Analysis documented in Federal Register 84(4), issued on 07 January 2019 and since documented in MPEP § 2106. While the claim recites that a “one or more processor” that performs the limitations encompassing mental processes, this simply represents implementing the abstract ideas with a computer. The additional limitations in relation to the computer, computer product, or computer system does not offer a meaningful limitation beyond generally linking the use of the method to a computer (see ALICE CORP. v. CLS BANK INT’L 573 U. S. ____ (2014)). The claim does not recite a particular machine applying or being used by the abstract idea. See also subsection I of the cited section and MPEP § 2106.05(f) which indicates that instructions to implement the abstract idea on a computer or that “using a computer as a tool to perform the abstract idea” are not sufficient to integrate a judicial exception into a “practical application” as interpreted by the courts. Furthermore, the claim does not include additional elements which are sufficient to amount to significantly more than the abstract idea. As discussed above, the additional elements of a generic computer to execute the abstract ideas and does not add significantly more that the abstract idea because since the one or more processors are merely a generic computer component with the computer being used as a tool for performing the abstract idea. Furthermore, the claim limitation of “receiving a sequence of imaging photoplethysmography (IPPG) signals measured from different regions of a skin of the subject in a time domain” is directed to extra solution activity of gathering data and does not include additional elements which are sufficient to amount to significantly more than the abstract idea. Furthermore, the claims limitation “outputting the vital sign signal corresponding to the reconstructed IPPG signals via an output interface” does not add significantly more than the abstract idea because merely outputting result is directed to extra solution activity. In consideration of each of the relevant factors and the claim elements both individually and in combination, claim 20 is directed to an abstract ideas without sufficient integration into a practical application and without significantly more. Response to Arguments Applicant's arguments filed 02/05/20226 have been fully considered but they are not persuasive. In response to Applicant’s arguments on pages 1-10, with respect to claim rejection under 35 USC 101 to claim 1, the examiner respectfully disagrees. The examiner maintains that the limitations in claim 1, “execute a cross-domain unrolling optimization iteratively minimizing a difference between the received iPPG signals and reconstructed iPPG signals, wherein the reconstructed iPPG signals have frequency coefficients determined in a frequency domain and transformed into the time domain of the received iPPG signals before computation of the difference between the received iPPG signals and the reconstructed iPPG signals, and wherein the reconstructed iPPG signals are obtained as output of an iPPG neural network trained in the frequency domain with machine learning to enforce a learned structure on the frequency coefficients of the reconstructed iPPG signals; determine the vital sign signal of the subject from the frequency coefficients of the reconstructed iPPG signals upon reaching a termination condition of the cross-domain unrolling optimization” are directed to an abstract because the claim limitations can be performed via mathematical concepts and mental process, with assistance of basic physical aids or with pen paper. The Applicant argues on pages 1-5, the some of the claim limitations can’t be performed by the human mind with pen and paper, the examiner respectfully disagrees. The examiner notes that claim 1 is rejected under 35 USC 101 because the execute a cross-domain unrolling optimization steps and determining the vital sign signal steps are directed to abstract idea that can be performed not only by human mind, but combination of human mind and mathematical correlations. The examiner maintains that the executing a cross-domain unrolling optimization iteratively minimizing a difference between the received iPPG signals and reconstructed iPPG signals, wherein the reconstructed iPPG signals have frequency coefficients determined in a frequency domain and transformed into the time domain of the received iPPG signals before computation of the difference between the received iPPG signals and the reconstructed iPPG signals can be perform by a human with pen and paper because these data are already processed by the process, and not electronic IPPG signals and these limitations can be performed by a mathematical concept. Furthermore, the determining the vital sign can also be perform by a human with pen and paper after receiving the reconstructed IPPG signals. The Applicant further argues that claim limitation wherein the reconstructed iPPG signals are obtained as output of an iPPG neural network trained in the frequency domain with machine learning to enforce a learned structure on the frequency coefficients of the reconstructed iPPG signals can’t be perform by a human mind, however, this limitation is directed to an abstract idea because it is directed to a mathematic concept. The examiner notes that the neural network is an algorithm/software and is directed to an abstract idea. The applicant further argues that limitations “receiving a sequence of iPPG signals measured from different regions of a skin of the subject in a time domain” and ““outputting the vital sign signal corresponding to the reconstructed IPPG signals via an output interface” does not add significantly more than the abstract idea because merely outputting result is directed to extra solution activity” can’t be performed by a human, however, these limitations weren’t interspersed as abstract ideas. The examiner has interpreted the receiving the iPPG signals as extra solution activity of gathering data and does not include additional elements which are sufficient to amount to significantly more than the abstract idea, and claim limitation “output the vital sign signal corresponding to the reconstructed IPPG signals via an output interface” does not add significantly more than the abstract idea because merely outputting result is directed to extra solution activity. The Applicant cited case law (SRI int’l v. Cisco) on page 4 and argues a human is not equipped to process raw iPPG signals similar to Federal Circuit recognized that human is not equipped to analyze network packet data, the examiner respectfully disagrees. The examiner not that the limitations in claim 1 in current application is not similar to the cited case law. Claim 1 does not limit that the iPPG signals are raw signals. The claim 1 is merely directed to a memory and processor, and that the processor configured to execute the cross domain unrolling poetization steps and determining the vital sign steps. Furthermore on page 5, the applicant argues that claim 1 is directed to a specific technical signal-reconstruction technique for remote PPG and not standalone concepts and not a generic “mathematical calculation”, the examiner respectfully disagrees. The examiner notes that claim 1 merely recite the term “remote” in the preamble and the claim does not limit any remote optical source and sensor. MPEP 2106 states claims that merely recite generic computer functions (e.g., using a computer to perform a mathematical calculation”) are often considered abstract ideas. Claim 1 is merely directed to a computer component (e.g., memory and processor) to perform the abstract idea. The judicial exception is not integrated into a “practical application” as defined by the Subject Matter Eligibility Analysis documented in Federal Register 84(4), issued on 07 January 2019 and since documented in MPEP § 2106. While the claim recites “a processor” and “memory” that performs the limitations encompassing mental processes and mathematical concepts, this simply represents implementing the abstract ideas with a computer. The additional limitations in relation to the computer, computer product, or computer system does not offer a meaningful limitation beyond generally linking the use of the method to a computer (see ALICE CORP. v. CLS BANK INT’L 573 U. S. ____ (2014)). The claim does not recite a particular machine applying or being used by the abstract idea. See also subsection I of the cited section and MPEP § 2106.05(f) which indicates that instructions to implement the abstract idea on a computer or that “using a computer as a tool to perform the abstract idea” are not sufficient to integrate a judicial exception into a “practical application” as interpreted by the courts. In response to applicant’s arguments on pages 6-10, that the claim 1 is directed to a technical improvement in the field of imaging photoplethysmography, the examiner respectfully disagrees. The examiner notes that claim 1 does not recite any limitations that are an improvement to the functioning of a computer. The Applicant argues that claim 1 provides a technical improvement in the field of iPPG relating to the effective and reliable estimation of a subject’s vital signals from multi-region iPPG signal measurements and non-contact iPPG system, however, the claim does not recite any limitation with regards to multi-region iPPG signal measurements and non-contact iPPG measurement. The examiner notes that claim 1 merely recite the term “remote” in the preamble and the claim does not limit any remote or non-contact optical source and sensor to measure multi-region and non-contact iPPG signals. Applicant further argues that the executing the cross-domain unrolling optimization iteratively minimizing a difference between the received iPPG signals and reconstructed iPPG signals is directed to improvement to the technical improvement in the field of imaging photoplethysmography, however, these limitations are directed to the abstract idea. The examiner notes that claim 1 does not recite additional claim elements and limitations other than the limitations that are directed to the abstract that is significantly more than the abstract idea, and integrate the claims 1 as a whole into a practical use and directed to an improvement to the technology. 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. Any inquiry concerning this communication or earlier communications from the examiner should be directed to SHAHDEEP MOHAMMED whose telephone number is (571)270-3134. The examiner can normally be reached Monday to Friday, 9am to 5pm. 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, Anne M Kozak can be reached at (571)270-0552. 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. /SHAHDEEP MOHAMMED/ Primary Examiner, Art Unit 3797
Read full office action

Prosecution Timeline

Sep 05, 2023
Application Filed
Nov 01, 2025
Non-Final Rejection — §101
Jan 14, 2026
Interview Requested
Feb 04, 2026
Applicant Interview (Telephonic)
Feb 05, 2026
Response Filed
Feb 21, 2026
Examiner Interview Summary
Mar 02, 2026
Final Rejection — §101
Mar 18, 2026
Interview Requested

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Study what changed to get past this examiner. Based on 5 most recent grants.

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3-4
Expected OA Rounds
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Grant Probability
99%
With Interview (+56.7%)
4y 10m
Median Time to Grant
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