Ex Parte Benndorf et alDownload PDFPatent Trial and Appeal BoardApr 11, 201311724657 (P.T.A.B. Apr. 11, 2013) Copy Citation UNITED STATES PATENT AND TRADEMARK OFFICE UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www.uspto.gov APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 11/724,657 03/15/2007 Goetz Benndorf 2006P01207US 2794 22116 7590 04/12/2013 SIEMENS CORPORATION INTELLECTUAL PROPERTY DEPARTMENT 170 WOOD AVENUE SOUTH ISELIN, NJ 08830 EXAMINER NGUYEN, HIEN NGOC ART UNIT PAPER NUMBER 3777 MAIL DATE DELIVERY MODE 04/12/2013 PAPER Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE __________ BEFORE THE PATENT TRIAL AND APPEAL BOARD __________ Ex parte GOETZ BENNDORF, KLAUS KLINGENBECK-REGN, and MICHAEL ZELLERHOFF __________ Appeal 2011 -007598 Application 11/724,657 Technology Center 3700 __________ Before TONI R. SCHEINER, STEPHEN WALSH, and JACQUELINE WRIGHT BONILLA, Administrative Patent Judges. WALSH, Administrative Patent Judge. DECISION ON APPEAL This is an appeal under 35 U.S.C. § 134(a) from the rejection of claims directed to a method for generating a data set with a rotation computer tomograph, and an apparatus for generating an image data set. The Patent Examiner rejected the claims for obviousness. We have jurisdiction under 35 U.S.C. § 6(b). We affirm-in-part. Appeal 2011-007598 Application 11/724,657 2 STATEMENT OF THE CASE The invention “relates to a method for separate three-dimensional presentation of arteries and/or veins of a vessel system in a part of the body of a vertebrate by means of a rotation computer tomograph.” (Spec. 1, [0002].) According to the Specification, “[p]rior art in this case are what are known as C-arm-angiographs, in which an x-ray source and a sensor arranged opposite this source are rotated in an approximately 200° arc around the part of a patient's body to be examined and between 50 and 500 x-ray images are recorded and digitally stored during this process. . . . However, with conventional 3D angiography it is not possible to make a sufficiently clear distinction between arterial and venous vessel system because of the recording times and the dynamics of the contrast medium.” (Id., [0003].) Claims 17-25, and 29-32 are on appeal. Claim 17 illustrates the subject matter on appeal and reads as follows: 17. A method for generating a data set of an artery of a vessel system in a part of a body of a vertebrate with a rotation computer tomograph, comprising: performing a masking run by the tomograph without an injection of contrast media around the part of the body; recording data of the masking run in a first scan over a defined scanning arc; performing a first filling run with the tomograph with a first injection of the contrast media around the part of the body, the first filling run comprising an arterial phase part and a venous phase part; recording, in a second scan over the defined scanning arc, data of the arterial phase of vessel contrasting during the first filling run; performing a second filling run with the tomograph with a second injection of the contrast medium around the part of the body, the second filling run comprising an arterial phase part and a venous phase part; Appeal 2011-007598 Application 11/724,657 3 recording, in a third scan over the defined scanning arc, data of the arterial phase of vessel contrasting of the second filling run; combining the data of the arterial phase of vessel contrasting of the first filling run and the data of the arterial phase of vessel contrasting of the second filling run into a combined data set so that arterial phase data of vessel contrasting is provided over the entire defined scanning arc; subtracting the data of the masking run from the combined data set to generate the data set of the artery of the vessel system; and using the data set of the artery of the vessel system for human observation. The Examiner rejected the claims under 35 U.S.C. § 103(a) as unpatentable over Schoenberg et al. (US 6,377,835 B1, April 23, 2002) in view of the admission of prior art at Specification 2. (Ans. 3-10.) DISCUSSION The Issue The Examiner’s position is that Schoenberg described a method for generating a data set that comprised a masking run, first and second filling runs over a defined scanning arc, and data combination. (Ans. 3-5.) The Examiner found that Schoenberg described combining the first filling run data and the second filling run data. (Id. at 4-5.) The Examiner found that Schoenberg did not disclose rotation computer tomography, and steps subtracting masking run data from filling run data and using the data for human observation. (Id. at 5.) Relying on the Specification’s disclosure that (i) collecting masking run data and filling run data with a rotation computer tomograph was known in the art, and (ii) subtracting the collected masking run data from the filling run data was a known method of processing the rotation computer tomograph data to generate a blood vessel data set was also known in the art, the Examiner concluded: Appeal 2011-007598 Application 11/724,657 4 It would have been obvious to one of ordinary skill in the art at the time of the invention to modify Schoenberg’s method to use rotation computer tomography and subtracting the data of the masking run from the combined data set to generate the data set of the artery of the vessel system and using the data set of the artery of the vessel system in a humanly perceptible manner as taught by the prior art disclose[d] by the application because by using subtraction only the contrasted vessel is visible in the resulting images. Using rotation computer tomography in place of MRI does not change the result of the image and only require[s] ordinary skill in the art. (Id. at 5.) The Examiner concluded that each of dependent method claims 18-25 would have been obvious, as the feature claimed was either disclosed or suggested by Schoenberg and the admitted prior art and within the skill of the ordinary artisan to adjust or optimize. (Id. at 5-7.) The Examiner performed a similar analysis for apparatus claims 29-32. (Id. at 8-9.) Appellants contend that the rejection is mistakenly premised on finding that Schoenberg disclosed a masking run and first and second filling runs. (App. Br. 9.) Appellants contend that a run is not a phase of a tomographic run, and further that the Examiner mistakenly “glossed over the express feature that all three of the scans are over the same scanning arc.” (Id.) Pointing out that Schoenberg used a full body scanner, not a rotation scanner, Appellants state: “it cannot be shown that each phase as disclosed in the Schoenberg reference is a scan ‘over the same scanning arc.’” (Id.) Further, Appellants contend that “[t]o more clearly distinguish a run from a phase within a run the invention of claim 17 was amended to expressly recite that data is recorded in first, second and third scans over a defined scanning arc.” (Id. at 10.) According to Appellants, the Schoenberg passages the Examiner cited actually do not support the Examiner’s findings, particularly Appeal 2011-007598 Application 11/724,657 5 with regard to the claimed recording steps, filling run features, data combining, and subtraction steps. (Id. at 11-12.) Findings of Fact 1. The Examiner relied on admissions in Appellants’ Specification concerning the state of the art before Appellants filed their Application. (Ans. 5.) Specifically, the Examiner relied on statements that rotation computer tomography was known, and subtracting masking run data from filling run data was a known process for deriving a data set for artery imaging. (Id., citing Spec. 2.) 2. The Specification states: [0004] With the previously known three-dimensional vessel presentation what are known as a masking run and a filling run are recorded. In the masking run the C-arm is rotated around the part of the patient's body or around the entire patient and the x- ray images are recorded over the predetermined angular range. Contrast media is then injected into the vessel of interest and a second set of x-ray images is recorded with a new C-arm rotation, mapping what is known as the filling run. The models of the two sequences of images are now subtracted from one another so that only the contrasted vessels (i.e. those containing contrast media) are still visible in the result. These are now reconstructed using a 3D reconstruction method into a three- dimensional data set. Alternatively masking and filling run can also be reconstructed separately and the resulting three- dimensional data sets subtracted from each other. [0005] The 3D angiography method according to the prior art as a rule delivers a three-dimensional data set which represents both a part of the arterial and also parts of the venous vessel system. The reason for this deficiency of current angiography systems can be found in the fact that the rotation time of the tomograph, at appr. 5 secs, is far longer than what is referred to Appeal 2011-007598 Application 11/724,657 6 as the arterial phase of the vessel contrasting, which only lasts 2 to 3 secs. Thereafter the contrast media migrates via the usual capillary paths into the venous vessel system, so that, after the execution of the arterial phase, a venous phase shows the vessel contrasting which will recorded in a later part of the rotation of the tomograph, so that a three-dimensional mixed structure made up of arteries and veins is produced. (Spec. 2.) 3. The Specification states: [0016] In this case a rotation computer tomograph is taken to mean any imaging method based on a penetration technique with computation of a three-dimensional model of the examined object. (Id. at 4.) 4. The Specification explains “masking run” as follows: [0017] A masking run in the sense of the present invention is the rotation computer tomograph run without the use of a contrast medium. (Id. at 4.) 5. The Specification explains “filling run” as follows: [0019] A filling run in accordance with the invention is to be seen as a run of the tomograph in which the hollow space to be examined, in this case vessels, is filled with contrast medium up to the level at which a suitable contrast is produced in the imaging method. (Id. at 4.) 6. The Specification explains combining data and subtracting data sets as follows : [0021] Combining the data from the filling runs into data sets is to be understood as combining, with the aid of a Appeal 2011-007598 Application 11/724,657 7 predetermined algorithm and where necessary with the aid of a human evaluation, subsets of the data of the individual filling runs into a new data set according to predetermined rules. In accordance with the invention the data is selected so that it is complementary and so that data is present over the entire scanning arc of the tomograph used, i.e. from all positions at which projection images will be recorded, which belongs either to the arterial phase of vessel contrasting or to the venous phase. [0022] A subtraction of data sets is, in accordance with normal usage of this expression by those skilled in the art for tomographic methods, to be understood as a computational procedure in which the measurement data of a background is subtracted from the measurement data of interest so that essentially only the measurement data of interest remains in the data set. (Id. at 4-5.) 7. Schoenberg’s patent is entitled “Method For Separating Arteries And Veins In 3D MR Angiographic Images Using Correlation Analysis.” 8. According to Schoenberg, the object of its invention was “to provide a method for conducting MR angiography (MRA) wherein images are produced containing clearly visually separated veins and arteries.” (Schoenberg, col. 2, ll. 37-40.) 9. Schoenberg explained that its object was achieved with “a method wherein the technique of correlation MRA is used to separate lung arteries from lung veins in contrast enhanced multi-phase 3D MRA data sets, that are acquired at a temporal resolution of several seconds. . . . Using reference signal-time-courses from manually selected regions of interest (ROI) in the main lung arteries and veins, arterial and venous correlation angiograms are computed.” (Id. at ll. 41-53.) Appeal 2011-007598 Application 11/724,657 8 10. Schoenberg’s “region of interest (ROI) is defined in a slice of an examination subject containing either a major pulmonary artery or vein. The average ROI signal as a function of time is then stored as a reference time curve for the subsequent cross-correlation analysis.” (Id. at ll. 56-60.) 11. According to Schoenberg, “Analysis of pulmonary enhancement kinetics shows that in healthy individuals there is only a short time window of approximately 3s during which only the pulmonary arteries are enhanced (FIG. 1). With increasing acquisition times per phase pulmonary arteries and veins enhance within the same image and it becomes impossible to separate them on the basis of their enhancement kinetics using conventional techniques.” (Id. at col. 3, ll. 4-11.) 12. The Examiner found that Schoenberg taught administering contrast agent in multiple boli, sequentially. (Ans. 4.) 13. Schoenberg stated that its “inventive method using cross-correlation analysis results in even further improved artery and vein separation when multiple boli are administered to the patient in the procedure for obtaining the 3D MRA data set. In particular, a dual bolus procedure has proven effective.” (Schoenberg, col. 3, ll. 12-17.) 14. Schoenberg taught that “the subtraction of a pre-contrast image also offers a very simple technique for the suppression of the constant background signal in multi-phase MRA.” (Id. at col. 5, ll. 22-24.) 15. Schoenberg described administering two contrast agent boli in a multi-phase scanning technique. (Id. at col. 7, l. 5 – col. 8, l. 33.) In one embodiment, “repetitive injections were synchronized with the Appeal 2011-007598 Application 11/724,657 9 first and third scan phase using programmable delays for the start of the pulse sequence and mechanical infusion.” (Id. at col. 7, ll. 32-34.) In another embodiment, 16. According to Schoenberg, “[t]he combined approach of multi-phase angiography, dual-bolus injection and correlation analysis allows the production of pure arteriograms and pure venograms with decent anatomic coverage and a spatial resolution of about 2 mm. In the analysis by a viewer the vessel patency could be evaluated to the level of the segmental vessels.” (Id. at col. 7, ll. 54-59.) 17. Schoenberg disclosed: All dual bolus measurements were performed on a 1.5-T MR system (Magnetom Vision, Siemens Medical Systems Inc., Iselin, N.J.), equipped with a resonant echo planar imaging (EPI) gradient overdrive (maximum gradient strength: 25 mT/m, shortest rise time to maximum: 300 μs). All exams used the standard 4-element phased-array body coil, centered on the chest. . . . The anterior margin of the 3D scan volume was positioned at the middle of the long heart axis. Posteriorly, as much of the pulmonary vasculature as possible was covered within the defined scan volume. (Id. at col. 6, ll. 43-57.) 18. Schoenberg’s Figure 4 is reproduced here: Appeal 2011-007598 Application 11/724,657 10 “FIG. 4 shows the time sequence of a multiple-bolus multi- phase 3D-Gd-MRA procedure used for obtaining the 3D MRA data set on which cross-correlation is performed in accordance with an embodiment of the inventive method.” (Schoenberg, col. 3, ll. 33-36.) 19. Schoenberg’s claim 1 reads: 1. A 3D magnetic resonance angiography method, comprising the steps of: defining a region of interest in an examination subject, said region of interest containing a major pulmonary vessel; injecting a contrast agent bolus into said examination subject and obtaining a plurality of 3D magnetic resonance angiography data sets from said examination subject before, during and after arrival of said bolus in said region of interest; selecting a slice from each of said data sets containing said region of interest; determining an average region of interest signal as a function of time and storing said average region of interest signal as a reference time curve; Appeal 2011-007598 Application 11/724,657 11 in the respective selected slices from the plurality of data sets, identifying a signal-time curve for the slice; for each of the selected slices, cross-correlating the signal-time curve obtained from the slice with said reference time curve, to obtain cross-correlation results; storing said cross-correlation results as a new 3D data set containing arterial and venous correlation maps; and computing maximum intensity projections from said arterial and venous correlation maps for producing visualized images of arterial and venous vasculature in said region of interest. (Id. at col. 8, ll. 40-67.) Principles of Law “[I]f a technique has been used to improve one device, and a person of ordinary skill in the art would recognize that it would improve similar devices in the same way, using the technique is obvious unless its actual application is beyond his or her skill.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 417 (2007). “One of the ways in which a patent’s subject matter can be proved obvious is by noting that there existed at the time of invention a known problem for which there was an obvious solution encompassed by the patent’s claims.” Id. at 419-420. Analysis Appellants contend the Examiner erred by finding Schoenberg described scans over a defined scanning arc. (See, e.g., Ans. 4.) Schoenberg used a Magnetom Vision, Siemens Medical Systems Inc. 1.5 Tesla MR machine (FF 17), and the Examiner found it was not a rotation tomograph (Ans. 5), thus conceding that Schoenberg did not use a C-arm that moves in an arc around the patient. Schoenberg described its scans in Appeal 2011-007598 Application 11/724,657 12 terms of a “defined scan volume” positioned with reference to the patient’s body (FF 17), not as a scan performed over an arc. The Specification defines a “rotation computer tomograph” broadly as “any” imaging method with computation of a 3D-model of the examined object, i.e. the machine is a method. (FF 3.) However, because the claim requires data collection over an “arc,” we assess the claim as the person of ordinary skill would understand it. In our view, the person of ordinary skill in the art would interpret the arc referred to in Appellants’ claims as the arc described by the C-arm of a rotation tomograph as it moves around a patient. The Examiner contends that because Schoenberg collected data over a region of interest from three scans of a patient “in the imaging device,” “all three scans are being scanned over the same scanning arc.” (Ans. 11.) We are not persuaded that a person of ordinary skill in the art would agree with the Examiner’s explanation. A person of ordinary skill in the art might appreciate that Schoenberg collected data from the same region of interest as Appellants’ method, effectively the same region under Appellants’ defined scanning arc, but Schoenberg collected the data from a “defined scan volume” (FF 17) using a static scanner, not by moving a C-arm through an arc. Notwithstanding Appellants’ unusual definition of a rotation computer tomograph as a method (FF 3), a person of ordinary skill in the art would reasonably interpret “over a defined scanning arc” to mean the arc over which the rotation tomograph’s C-arm moves. We agree with Appellants that the Examiner erred in finding that Schoenberg collected data over a defined scanning arc in the sense that Appellants’ method does. We conclude, however, that this error is not fatal to the case for obviousness because the rejection made up for that deficiency Appeal 2011-007598 Application 11/724,657 13 by expressly relying on the prior art’s practice of rotation tomography, which collected data in masking and filling runs, and subtracted masking run data from filling run data to obtain the 3D vessel image. (Ans. 5, citing Spec. 2.) As explained in the Specification, in the masking run of conventional 3D angiography in use before Appellants filed their Application, “the C-arm is rotated . . . and the x-ray images are recorded over the predetermined angular range.” (FF 2.) There does not appear to be a material difference between the prior art practice of scanning over a “predetermined angular range” and the claimed step of scanning over a “defined scanning arc,” nor do Appellants argue there is a difference. The prior art method performed masking and filling runs, and then subtracted the masking and filling sequences of images from one another “so that only the contrasted vessels (i.e. those containing contrast media) are still visible in the result.” (FF 2.) For the prior art subtraction step to have rendered an image in which only the contrasted vessels were visible, we find it implicit that the filling run must have been done over the same predetermined angular range, i.e., defined scanning arc, as the masking run. The dispositive issue presented by the Examiner’s rejection is simply whether it would have been obvious to apply Schoenberg’s multi-bolus method to the prior art rotation tomography method that performed a masking and a filling run over a defined scanning arc and then subtracted so that the contrasted vessels were visible. For the reasons that follow, we conclude the rejection should be affirmed. Because our reasoning relies on added findings that (i) Appellants’ “defined scanning arc” is the same as the admitted prior art’s “predetermined angular range,” and (ii) the admitted Appeal 2011-007598 Application 11/724,657 14 prior art’s masking and filling scans must have been over the same predetermined angular range, we designate the affirmances as new grounds of rejection. Claim 17 Appellants contend that Schoenberg did not disclose masking and filling runs, but instead disclosed only phases of a tomographic run. (App. Br. 9.) The Examiner found this argument unpersuasive because according to Appellants’ Specification at 4, “a run is just a scan of vessel that is filled with contrast medium.” (Ans. 10.) The Examiner’s interpretation of “run” is consistent with the masking and filling run definitions in the Specification. (See FF 4 and 5.) The evidence supports the Examiner’s finding that Schoenberg described a tomograph run without contrast medium, i.e., a masking run, and that Schoenberg described a tomograph run with contrast agent in a vessel, i.e., a filling run. (FF 13 and 14.) We agree with Appellants’ reiterated contentions that Schoenberg did not describe data collection over a defined scanning arc. (App. Br. 10-12.) However, the rejection explicitly relied on Appellants’ admission that using a rotation computer tomograph for 3D vessel imaging was already known in the art, and that the known method included data collection over a predetermined angular range, i.e., a defined scanning arc. It is not necessary for the Examiner to show that Schoenberg’s phases, or runs, were scans over the same scanning arc because the rejection proposed that it would have been obvious to apply Schoenberg’s multi-bolus visualization scheme to the known method of rotation tomography done over a predetermined scanning arc. Appeal 2011-007598 Application 11/724,657 15 Claims 20-23 have not been argued separately and fall with claim 17. 37 C.F.R. § 41.37(c)(1)(vii). Claim 18 Appellants contend that claim 18’s method would have been non- obvious “because there is no disclosure in the prior art of combining data of venous phases in two different filling runs to provide data with venous vessel contrasting over the entire defined scanning arc and then ‘subtracting the data of the masking run from the further combined data set ....’” (App. Br. 14-15.) The Examiner found this argument unpersuasive. (Ans. 11-12, citing Schoenberg’s disclosure.) The evidence supports the Examiner’s finding that Schoenberg taught imaging veins or arteries. (FF 8-11.) The evidence also supports the Examiner’s finding that Schoenberg taught collecting the data and subtracting the combined runs. (FF 13-16). We agree with the Examiner that Schoenberg, taken with the admitted prior art, suggested Appellants’ method. Claim 19 has not been argued separately and falls with claim 18. 37 C.F.R. § 41.37(c)(1)(vii). Claim 24 Claim 24 is dependent from claim 17 and it specifies that the first and second scanning runs are performed in the same direction, that the first injection is performed when first filling run starts, and that the second injection is performed after the second filling run has been performed. Appeal 2011-007598 Application 11/724,657 16 Addressing claims 24 and 25 together, the Examiner found that Schoenberg disclosed several relevant embodiments for timing the second injection or the second filling run: the first injection of the contrast medium is injected when the first filling run starts and the second injection of the contrast medium is injected after the second filling run has been performed (see col. 7, lines 5-43); wherein the first injection of the contrast medium is injected when the first filling run starts and the second injection of the contrast medium is injected when the second filling run starts, and wherein the second filling run starts when the contrast medium in the first filling run has been flushed out of veins of the vessel system (see col. 7, lines 5-43 and Fig. 4). (Ans. 7, emphasis added.) Schoenberg disclosed that “repetitive injections were synchronized with the first and third scan phase . . . .” (FF 15), which supports the Examiner’s finding that Schoenberg taught a second injection after the second filling run was performed. On this evidence, we conclude that the evidence supports the rejection of claim 24. Appellants contend that the rejection concluded it would have been obvious to perform the second injection when the second filling run starts, but that is not what is claimed in claim 24. (App. Br. 15.) We agree, but that conclusion was directed to the limitations of claim 25. Claim 25 Claim 25 is dependent on claim 17 and recites: “the second filling run starts when the contrast medium in the first filling run has been flushed out of veins of the vessel system.” Appeal 2011-007598 Application 11/724,657 17 Addressing claims 24 and 25 together, the Examiner found that Schoenberg disclosed at least three relevant embodiments for timing the second injection: the first injection of the contrast medium is injected when the first filling run starts and the second injection of the contrast medium is injected after the second filling run has been performed (see col. 7, lines 5-43); wherein the first injection of the contrast medium is injected when the first filling run starts and the second injection of the contrast medium is injected when the second filling run starts, and wherein the second filling run starts when the contrast medium in the first filling run has been flushed out of veins of the vessel system (see col. 7, lines 5-43 and Fig. 4). (Ans. 7, emphasis added.) Appellants contend: “This is inconsistent with the Examiner's citation to col. 7, lines 5-43 of Schoenberg. The prior art does not completely flush the contrast medium of the first filling run out of veins before the second filling run starts.” (App. Br. 15.) The Examiner responds that Schoenberg’s Figure 4 shows “flush out or wash bolus contrast agent with NaCl . . . to wash out contrast medium (CM).” (Ans. 12.) While Schoenberg’s Figure 4 does show that most of the contrast medium has been washed out when the second injection is done, Figure 4 also shows that some contrast medium is still present in the veins (VEN) when the second bolus of contrast medium (CM) is injected. We therefore agree with Appellants that the evidence does not support the rejection’s finding that Schoenberg disclosed starting the second filling run when the contrast medium of the first filling run has been completely flushed out. The rejection of claim 25 is therefore reversed. Appeal 2011-007598 Application 11/724,657 18 Claim 29 Claim 29 reads: 29. An apparatus for generating an image data set of an artery of a vessel system in a part of a body of a vertebrate, comprising: a rotation computer tomography apparatus that obtains: a recording of a masking run during a first scan over a defined scanning arc to provide data for a masking run without an injection of contrast media around the part of the body, a recording of a first filling run with a first injection of contrast media around the part of the body to record data of an arterial phase of vessel contrasting during a second scan over the defined scanning arc, and a recording of a second filling run with a second injection of contrast media around the part of the body to record data of an arterial phase of vessel contrasting during a third scan over the defined scanning arc; and a computation device that: combines the data of the arterial phase of vessel contrasting of the first filling run obtained during the second scan over the defined scanning arc and the data of the arterial phase of vessel contrasting of the second filling run obtained during the third scan over the defined scanning arc into a combined data set, and subtracts the data of the masking run from the combined data set to generate the image data set of the artery of the vessel system. Appellants contend: “The prior art does not disclose this combination of recordings during three different scans over the same defined scanning arc.” (App. Br. 13.) The admitted prior art described two scans, a masking and filling run, over a predetermined angular range, which is the same as a defined scanning arc. (FF 2.) Adding a third scan, as suggested by Schoenberg, would have been an obvious modification, as discussed above. Appellants contend the claimed “computation device” is a distinguishing feature. (App. Br. 13.) We disagree that the computation device is a nonobvious feature. The Examiner found that Schoenberg disclosed storing scan data, cross-correlating data, and computing data, Appeal 2011-007598 Application 11/724,657 19 among other things. (Ans. 8-9, citing, e.g., Schoenberg’s claim 1.) The evidence supports these findings. (FF 19.) Given that the known methods included subtracting masking run data, we agree with the Examiner that a computation device was in the prior art. Appellants contend “[t]he rejection argues without support that the Schoenberg reference discloses combining data of the arterial phase obtained during a first scan (a second recording) with data of an arterial phase obtained during a second scan (a third recording) but, despite citation of numerous lines of text, Appellants cannot find disclosure of this subject matter.” (App. Br. 13.) We agree with the Examiner. Schoenberg’s claim 1, for example, defines a method comprising obtaining a plurality of data sets and combining data from scans before, during, and after contrast medium is injected. (FF 19.) Appellants argue the rejection should be reversed “because there is no disclosure in the prior art of combining data of venous phases in two different filling runs to provide data with venous vessel contrasting over the entire defined scanning arc and then ‘subtracting the data of the masking run from the further combined data set ....’ The rejection provides no citation in support of obviousness. Also, the rejection somehow equates a correlation map with a filling run. This is not understood and the Examiner is apparently in error. Otherwise the Examiner must provide support for this.” (App. Br. 16.) We again agree with the Examiner. No particular combination of data beyond what Schoenberg taught is required by Appellants’ method, which may be done by any “predetermined algorithm.” (FF 6.) Schoenberg taught subtraction (FF 14), and it is admitted that the known prior art methods used subtraction (FF 2), and no particular method beyond what was known in the art is required by Appellants’ method, which is done “in accordance with Appeal 2011-007598 Application 11/724,657 20 normal usage of this expression by those skilled in the art for tomographic methods” (FF 6.) Claim 30 Appellants contend that claim 30 is nonobvious “because there is no disclosure in the prior art of combining data of venous phases in two different filling runs to provide data with venous vessel contrasting over the entire defined scanning arc and then ‘subtracting the data of the masking run from the further combined data set ... .’” (App. Br. 16.) This argument is unpersuasive. The Examiner concluded it would have been obvious to use Schoenberg’s steps with a rotation tomograph to visualize veins because Schoenberg taught visualizing veins. (Ans. 9.) We agree. As both Schoenberg and the admitted prior art used subtraction to produce the vessel image, we again agree that it would have been obvious to use a computation device to do so. Appellants contend that “the rejection somehow equates a correlation map with a filling run. This is not understood and the Examiner is apparently in error.” (App. Br. 16.) We disagree that the rejection equated a correlation map with a filling run. (See Ans. 9.) Claim 31 has not been argued separately and falls with claim 30. 37 C.F.R. § 41.37(c)(1)(vii). Claim 32 Claim 32 is dependent from claim 30 and recites “wherein the arterial phase part of the second filling run occurs in the venous phase part of the first filling run and the venous phase part of the second filling run occurs in Appeal 2011-007598 Application 11/724,657 21 the arterial phase part of the first filling run.” Appellants contend that Schoenberg did not disclose this subject matter. (App. Br. 16.) The Examiner responds: Appellants’ argument is not persuasive because Schoenberg discloses the first filling run starting at first CM that shows artery (ART) then vein (VEN); then second filling run starting at second CM that shows vein (VEN) then artery (ART) (see col. 7, lines 5-58 and Fig. 4, the venous overlay the artery therefore arterial phase part of the second filling run occurs in the venous phase part of the first filling run and the venous phase part of the second filling run occurs in the arterial phase part of the first filling run; in Fig. 4). (Ans. 13.) Put another way, Schoenberg’s overlap satisfies claim 32’s “occur in” features. The overlap is illustrated in Schoenberg’s Figure 4. (See FF 18.) We find the Examiner’s summary accurate, and therefore find Appellants’ argument unpersuasive. 37 C.F.R. § 41.50(b) This decision contains a new ground of rejection pursuant to 37 C.F.R. § 41.50(b) (effective September 13, 2004, 69 Fed. Reg. 49960 (August 12, 2004), 1286 Off. Gaz. Pat. Office 21 (September 7, 2004)). 37 C.F.R. § 41.50(b) provides “[a] new ground of rejection pursuant to this paragraph shall not be considered final for judicial review.” 37 C.F.R. § 41.50(b) also provides that the Appellant, WITHIN TWO MONTHS FROM THE DATE OF THE DECISION, must exercise one of the following two options with respect to the new ground of rejection to avoid termination of the appeal as to the rejected claims: Appeal 2011-007598 Application 11/724,657 22 (1) Reopen prosecution. Submit an appropriate amendment of the claims so rejected or new evidence relating to the claims so rejected, or both, and have the matter reconsidered by the examiner, in which event the proceeding will be remanded to the examiner. . . . (2) Request rehearing. Request that the proceeding be reheard under § 41.52 by the Board upon the same record. . . . SUMMARY We affirm the rejection of claims 17-24 and 29-32 under 35 U.S.C. § 103(a) as unpatentable over Schoenberg and admitted prior art. We reverse the rejection of claim 25 under 35 U.S.C. § 103(a) as unpatentable over Schoenberg and admitted prior art. AFFIRMED-IN-PART; 37 C.F.R. § 41.50(b) lp Copy with citationCopy as parenthetical citation