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 .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 10/22/2024 was being considered by the examiner.
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) 13, 14, 17, 18, 21, 23, 24 and 25 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al. (US 2005/0123097 A1), in view of Behling (US 2014/0307853 A1) and further in view of Zhao (US 2021/0244374 A1).
With regards to claim 13, Wang teaches an X-ray imaging source in which an electron beam is generated and directed onto an end-window transmission target to generate an X-ray flux. Wang identifies a cathode or electron emitter, an evacuated tube or chamber, an end-window target or anode, and associated operating electronics. (Wang [0072]–[0076]; Figs. 1 and 7.)
Wang teaches that the target includes a substantially X-ray-transparent substrate carrying one or more thin target foils or target layers. Wang discloses separate target-foil areas on a common planar substrate and identifies low-atomic-number substrate materials such as beryllium or aluminum. (Wang [0036] – [0037], [0074], [0086]; Figs. 1, 2, 6, and 7.)
Wang teaches that the target layer generates X-rays when struck by the electron beam and that the electron-beam impact location may be selected among different target regions. Wang states that the desired X-ray spectrum may be selected by switching the electron-beam spot among different foils and also teaches selectively moving the focal spot to different positions on a target. (Wang [0036], [0083]; Figs. 1, 2, and 7.)
Wang also teaches acquiring a first image while the electron beam strikes one target region, acquiring a second image while the beam strikes another target region, and partially or completely subtracting the images to remove undesired features. (Wang [0051].)
Wang further identifies conventional imaging environments having a source, a subject or sample, and an image receptor positioned across the subject, including a C-arm system in which the source and receptor are positioned on opposite sides of the subject. (Wang [0080].)
Wang does not expressly teach that the second beam position is a beam-dump position arranged so substantially no radiation generated at that position reaches the detector. Wang’s second acquisition in paragraph [0051] is another desired target-foil exposure rather than a low-primary dump or reference exposure. (Wang [0051].)
Behling teaches the missing low-output beam-dump state. Behling discloses an X-ray anode having target portions and beam-dump portions arranged alternately along the focal track. When the electron beam strikes a target portion, useful X-rays are generated; when the electron beam strikes a beam-dump portion, substantially no useful X-rays for imaging are generated, allowing modulation from approximately 100 percent toward zero. (Behling [0010]–[0014], [0045]–[0052]; Figs. 1–3.)
Behling additionally teaches deflection and focusing structures that establish different focal-spot relationships with the target and dump portions. (Behling [0059]–[0061], [0076]–[0081]; Figs. 6 and 7.) Behling further teaches dump geometry in which the dump bottom does not have a direct line of sight to the X-ray window and discusses minimizing off-focal radiation received by detector cells. (Behling [0081]–[0089]; Figs. 7–9.)
Zhao teaches an X-ray source, subject, downstream detector, processor, and subtractive image correction. (Zhao [0105]–[0112]; Figs. 1A–5.) Zhao also teaches deflecting an electron beam inside an X-ray source with a changing magnetic field or solenoid so that the electron beam strikes a different anode location. (Zhao [0330]; Fig. 15A.)
In view of the utility of rapidly switching the electron beam between imaging and substantially non-imaging operating states while maintaining controlled focal-spot positioning, it would have been obvious to a person of ordinary skill in the art at the time of the invention to modify Wang with the teachings of Behling and Zhao to direct the electron beam between a target-layer position and a beam-dump position while electronically steering the beam and subtracting the resulting images in order to obtain a reference image representative primarily of source-generated secondary radiation for subtraction from the useful imaging exposure, thereby predictably reducing secondary-emission artifacts.
With regards to claim 14, Wang modified teaches the claimed invention according to claim 13, and Wang further teaches C-arm imaging in which the X-ray source and image receptor are mounted on opposite ends of a C-arm and moved about the subject to obtain images from different directions. (Wang [0080].)
Wang fails to expressly teach a manipulator configured to move the X-ray source and sample position relative to one another.
Zhao likewise teaches a mover for moving the X-ray source relative to the subject and/or moving the source and detector relative to the subject. (Zhao [0484]; Figs. 1A and 1B.)
In view of the utility of controlling relative source-object positioning while preserving a desired imaging geometry for multiple corresponding acquisitions, it would have been obvious to a person of ordinary skill in the art at the time of the invention to modify Wang with the teachings of Zhao to provide the claimed manipulator for moving the X-ray source and sample position relative to one another, thereby predictably permitting repeatable acquisition from selected imaging geometries.
With regards to claim 17, Wang modified discloses the claimed invention according to claim1, and further teaches an actuator arranged to move the target relative to the electron beam [0083] – [0084]. Claim 16 and Figure 7).
With regards to claim 18, see the rejection of claim 14.
With regards to claim 21, Wang teaches generating an electron beam, directing it to a first target region, acquiring a first image, changing the impact location to a second target region, acquiring a second image, and subtracting the images. (Wang [0051]; Figs. 1, 2, and 7.) Wang also teaches the layered target and substrate architecture. (Wang [0036]–[0037], [0074], [0086].)
Wang does not expressly perform the second acquisition at a beam-dump position arranged so substantially no dump-generated radiation reaches the detector. (Wang [0051].)
Behling teaches directing the electron beam between target portions and beam-dump portions, with the dump condition producing substantially no useful X-rays and with dump geometry limiting radiation toward the X-ray window. (Behling [0045]–[0052], [0059]–[0061], [0081]–[0089]; Figs. 2–9.)
Zhao teaches electronic beam deflection to a different anode location and processor-based subtraction of unwanted image components. (Zhao [0105]–[0112], [0330]; Figs. 1A–5 and 15A.)
In view of the utility of obtaining a controlled substantially non-imaging source state while electronically steering the electron beam and subtracting corresponding image data, it would have been obvious to a person of ordinary skill in the art at the time of the invention to modify Wang with the teachings of Behling and Zhao to use Behling's beam-dump condition as Wang's second reference state, acquire the corresponding second image, and subtract it from the first target-on image, thereby predictably reducing common source-generated background.
With regards to claim 23, Wang modified discloses the claimed invention according to claim 21, but fails to expressly disclose setting pixel values of the second X-ray image below a predetermined threshold to zero before generating the first difference image.
It is Official Notice that, it is well known in the image-processing arts to threshold a reference image, background image, dark-frame image, calibration image, or other reference image data by assigning pixel values below a selected threshold to zero before subsequent image-processing operations. Such thresholding techniques were conventionally used to suppress low-level noise, remove insignificant background information, reduce false image artifacts, and improve subsequent subtraction, comparison, segmentation, masking, or calibration operations. Likewise, it was well known to apply similar thresholding operations to reference image data sets, background data sets, calibration data sets, or other image data prior to performing image subtraction.
In view of the utility of suppressing low-level background information and insignificant image data before subtraction, it would have been obvious to a person of ordinary skill in the art at the time of the invention to modify Wang with the conventional thresholding techniques taken under Official Notice by assigning pixel values of the second X-ray image below a predetermined threshold to zero before generating the first difference image in order to reduce the contribution of low-level background signals and thereby predictably improve the quality of the resulting difference image. The particular placement of the thresholding operation within the image-processing sequence constitutes a matter of routine implementation and design choice because thresholding performs the same known function regardless of whether the reference image is subsequently used for subtraction, comparison, masking, or calibration.
With regards to claim 24, Wang teaches the claimed invention according to claim 21, but fails to disclose moving an object to be imaged so that a position of an image of the object on the detector is substantially the same for said first X-ray image and said second X-ray image.
Zhao teaches a mover for changing the relative source-subject relationship and teaches matching live measurements to first measurements, including determining translational and rotational shifts from the best-matching projected image. (Zhao [0484], [0530]–[0532]; Fig. 28.)
In view of the utility of maintaining corresponding image locations during subtraction processing, it would have been obvious to a person of ordinary skill in the art at the time of the invention to modify Wang with the teachings of Zhao to move the object or otherwise adjust the source-object geometry so that the object occupies substantially the same detector position in both images, thereby predictably reducing subtraction artifacts caused by misregistration.
With regards to claim 25, Wang discloses the claimed invention according to claim 21, but fails to expressly disclose aligning the first and second images before generating the first difference image.
Zhao teaches matching first and live measurements and determining translational and rotational shifts. (Zhao [0530]–[0532]; Fig. 28.)
In view of the utility of aligning corresponding image features before pixelwise subtraction, it would have been obvious to a person of ordinary skill in the art at the time of the invention to modify Wang with the teachings of Zhao to align the first and second images before generating the difference image, thereby predictably reducing false edge and motion residuals.
Claim(s) 15,16,19,20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al. (US 2005/0123097 A1), in view of Behling (US 2014/0307853 A1) and further in view of Zhao (US 2021/0244374 A1) and Schu (WO 2020/052773 A1, using the US 2022/0068586 A1 for citations).
With regards to claim 15, Wang modified discloses the claimed invention according to claim 13, but fails to expressly disclose a beam-limiting element arranged between the electron source and the target.
Schu teaches a microfocus X-ray tube having an objective or lens diaphragm positioned in the electron-beam path between the electron-source side and the target. Schu explains that the aperture strongly limits the electron beam, particularly during high-resolution operation. (US 2022/0068586 A1 [0002]–[0007], [0022]–[0025]; Fig. 1.)
In view of the utility of restricting and defining the electron beam before it reaches the target so that a small and controlled focal spot is produced, it would have been obvious to a person of ordinary skill in the art at the time of the invention to modify Wang with the teachings of Schu to arrange a beam-limiting element between the electron source and the target, thereby predictably improving beam confinement and focal-spot control.
With regards to claim 16, Wang modified discloses the claimed invention according to claim 13, but fails to expressly disclose that X-ray radiation generated by interaction between the electron beam and the beam-limiting element reaches the detector when the electron beam is directed to both the first and second positions.
Schu teaches that electrons striking the metal body of the objective aperture generate stray X-ray radiation, that the radiation may penetrate the target, and that an image of the diaphragm opening may appear on the image receptor. (US 2022/0068586 A1 [0002]–[0004]; Fig. 1.)
Schu further explains that component-generated stray radiation increases overall image brightness and degrades contrast. (US 2022/0068586 A1 [0002]–[0003].)
The aperture is upstream of both selectable downstream beam destinations. Thus, aperture-generated radiation is produced from the same upstream beam-limiting structure during operation at either target-layer or dump position, absent a separate intervening blocking structure. Schu expressly teaches that such aperture-generated radiation can reach the image receptor. (US 2022/0068586 A1 [0003]–[0004]; Fig. 1.)
In view of the utility of accounting for aperture-generated stray radiation that is common to multiple source states, it would have been obvious to a person of ordinary skill in the art at the time of the invention to modify Wang with the teachings of Schu so that radiation generated by interaction between the electron beam and the common upstream beam-limiting element reaches the detector during both the first and second beam-position acquisitions, thereby predictably providing a common background component suitable for subtraction.
With regards to claims 19 and 20, see the rejections of claims 15 and 16, respectfully.
Claim(s) 22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al. (US 2005/0123097 A1), in view of Behling (US 2014/0307853 A1) and further in view of Zhao (US 2021/0244374 A1) and Barnes et al. (US 2012/0002898 A1).
With regards to claim 22, Wang modified discloses the claimed invention according to claim 21, but fails to expressly teach determining a scale factor from the respective exposure times of the first and second X-ray images, scaling pixel values, and thereafter generating the first difference image.
Barnes teaches capturing images using different exposure durations and compensating image values with scaling factors selected according to the exposure-time relationship. Barnes explains that an image acquired with four times the exposure duration may be given a corresponding one-fourth scaling relationship and teaches adjusting image values so the differently exposed images are represented on a common scale. (Barnes; [0127]–[0131], [0137]–[0139]; Figs. 12 and 13.)
In view of the utility of normalizing image intensity differences caused by differing exposure times before image subtraction, it would have been obvious to a person of ordinary skill in the art at the time of the invention to modify Wang with the teachings of Barnes to determine the claimed scale factor from the respective exposure times and scale the pixel values before generating the difference image, thereby predictably preventing exposure-duration differences from appearing as false subtraction residuals.
Claim(s) 26 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al. (US 2005/0123097 A1), in view of Behling (US 2014/0307853 A1) and further in view of Zhao (US 2021/0244374 A1) and Mistretta et al. (US 4,482,918).
With regards to claim 26, Wang modified teaches the claim according to claim 21 and also Wang teaches selecting among multiple target regions and acquiring corresponding images. (Wang [0036], [0051], [0083]; Figs. 1, 2, and 7.)
Behling teaches distinguishable target and dump states along the focal track. (Behling [0045]–[0052]; Figs. 1–3.)
Together, those references provide multiple physically selectable source states, including useful target production and a substantially non-imaging dump/reference state.
The Wang modified set does not expressly teach the complete ordered difference-of-differences processing recited by claim 26.
Mistretta teaches X-ray hybrid subtraction using multiple source or acquisition conditions. Mistretta acquires low- and high-energy pre-contrast images and corresponding post-contrast images, subtracts the post-contrast and pre-contrast images to form separate low- and high-energy temporal difference images, applies suitable scaling coefficients or weighting factors, and subtracts one temporal difference image from the other to form a final hybrid difference image. (Mistretta; col. 3:25–68; col. 7:40–col. 8:35; col. 10:1–col. 11:20; Fig. 4; claims 1, 7, and 9.)
More specifically, Mistretta states that the low-energy post-contrast image is subtracted from a stored low-energy pre-contrast image to form a low-energy temporal difference image; the high-energy post-contrast image is subtracted from the stored high-energy pre-contrast image to form a high-energy temporal difference image; the temporal difference images are scaled with suitable coefficients; and one scaled difference image is subtracted from the other to produce the hybrid image. (Mistretta, col. 3:44–68; col. 10:55–col. 11:20; Fig. 4.)
In view of the utility of sequentially removing multiple unwanted image components through staged subtraction processing, it would have been obvious to a person of ordinary skill in the art at the time of the invention to modify Wang with the teachings of Behling and Mistretta to acquire the claimed additional source-state image, generate separate intermediate difference images, scale the second difference image, and subtract the scaled second difference image from the first difference image, thereby predictably producing a final compensated image in which common unwanted source-generated components are reduced.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Corum (6,101,287) independently confirms that dark and picture frames obtained using different integration times are corrected by adjusting the dark-frame values according to the respective integration times before subtraction. (Corum; col. 4:46–65; claims 6, 14, and 18; Fig. 4.)
Nichani (US 5,949,901) likewise teaches optionally registering two acquired images before normalization and subtraction and identifies two-dimensional cross-correlation as a known registration technique. (Nichani; col. 5:31–col. 6:35; Fig. 4; claim 12.)
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DJURA MALEVIC whose telephone number is (571) 272-5975. The examiner can normally be reached M-F (9-5).
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/DJURA MALEVIC/Examiner, Art Unit 2884
/UZMA ALAM/Supervisory Patent Examiner, Art Unit 2884
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