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 .
Response to Arguments
Applicant's arguments filed 02/26/2026 have been fully considered but they are not persuasive.
Applicant argues that Rahmer fails to teach or suggest processing circuitry that “generates corrected projection data by performing sensitivity correction on the projection data by using a system function previously acquired for each piece of projection data, wherein the system function is a deconvolution coefficient”, applicant further asserts that the office action improperly refers to a “system matrix X” and “processing circuitry 30” which applicant contends are not expressly disclosed in Rahmer.
Examiner respectfully disagrees, Rahmer expressly teaches that magnetic particle imaging reconstruction requires knowledge of a system function describing the system response to a spatial distribution of magnetic particles, and that image reconstruction is performed by inverting the system function to recover the particle distribution from the measured signals [0007]. The measured MPI signal corresponds to the response of the imaging system to the spatial particle distribution and therefore represents a convolution of the system response with the particle distribution. Accordingly, inversion of the system function during reconstruction inherently corresponds to a deconvolution of the measured signal with the system response on order to recover the underlying particle distribution. Thus, Rahmer’s reconstruction process necessarily performs signal correction using a previously determined system function in a manner consistent with the claimed use of a deconvolution coefficient.
Applicant further argues that Rahmer does not discloses a “system matrix X” or “processing circuitry 30”. While Rahmer may not use the exact terminology cited in the office action. Rahmer clearly discloses that the acquired detection signals are processed by a computer executing a reconstruction algorithm to reconstruct the spatial distribution of magnetic nano articles [0005]. One of the ordinary skills in the art would recognize that such reconstruction operations are implemented using processing hardware executing the reconstruction algorithm, which reasonably corresponds to claimed processing circuitry performing the recited signal processing operation. The particular labels used in the references to describe computational components do not limit the functional teachings of the reference.
Applicants’ argument that Rahmer does not discloses a system function corresponding to the claim deconvolution coefficient is also not persuasive. As explained above, Rahmer teaches that the reconstruction algorithm requires inversion of the system function describing system response [0007]. In signal processing terms, inversion of the system response function corresponds to deconvolution of the measured signal with the system response in order to recover the original spatial particle distribution. Therefore, the claimed characterization of the system function as a “deconvolution coefficient” merely express the mathematical interpretation of the same reconstruction operation already disclosed in Rahmer with respect to the generation of the system function. Weber teaches performing calibration measurement using magnetic particle samples at multiple spatial positions to detect calibration signals and generate a system matrix used for reconstruction of the magnetic particle concentration [0004-6, 32]. These calibration measurements correspond to determining the system response for different spatial locations of magnetic particles, thereby generating the system function used for reconstruction. This teaching corresponds to the claimed step of generating the system function based on magnetization changed measured in a calibration structure containing magnetic nanoparticles. Both Rahmer and Weber address MPI image reconstruction based on system response functions, and Weber expressly teaches calibration procedures approach for determining the system matrix used in reconstruction. Combining Weber’s calibration approach with Rahmer’s reconstruction method would therefore represent a predictable use of known techniques for determining the system response used in MPI reconstruction.
Claim Rejections - 35 USC § 103
3. 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 of this title, 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.
Claims 1-6 ad 8-10 are rejected under 35 U.S.C. 103 as being unpatentable over Rahmer (U.S. Publication 20160216355) in view of Weber (U.S. Publication 20170020407).
Regarding claim 1, Rahmer teaches a magnetic particle imaging device for generating a magnetic nanoparticle image indicating spatial distribution of magnetic nanoparticles in a subject, the magnetic particle imaging device comprising (fig. 1 (30) a MPI device toto reconstruct the spatial distribution of magnetic nanoparticles within a subject based on detected MPI signals (0068-71)):
a linear zero magnetic field generation [[unit]] coil (fig. 1 (12)) to generate a linear zero magnetic field region in the subject and to move the linear zero magnetic field region in a predetermined direction (coils 12 to generate a filed free region in which field free region is a field free line [0061] further focus shift coils 18 apply additional magnetic field that translate the field free line through imaging volume along controlled , predetermined trajectories by adjusting coil currents [0062]);
an excitation magnetic field application [[unit]] coil to apply an AC excitation magnetic field to a magnetic field region including the linear zero magnetic field region (fig. 1 coils 14, to apply time varying AC excitation magnetic field to imaging region including the zero field region tin order to excite magnetic nanoparticles [0063-65]);
detector to detect a magnetization change of the magnetic nanoparticles caused by the excitation magnetic field (fig. 1 coils 16, to detect voltages induced by magnetization changes of magnetic nanoparticles in response to the applied excitation magnetic field [0067]); and
processing circuitry (fig. 3 reconstruction unit 30, and processing circuitry to process detected signals and reconstruct an image of the magnetic nanoparticles distribution [0068-72]), wherein
when generating the magnetic nanoparticle image, the processing circuitry
makes the linear zero magnetic field generation [[unit]] coil form the linear zero magnetic field region in an image capture target as the subject and scan, rotate, or scan and rotate the linear zero magnetic field region (fig. 2 controlling the selection coils 12 and focus/shift field coils 18 to move the field free line along multi directional scanning trajectories through the subject during image acquisition [0062, 66-68]. Such trajectories involve controlled scanning of the zero field region to sample different spatial locations for image reconstruction),
makes the excitation magnetic field application [[unit]] coil apply the excitation magnetic field (applying the AC drive field via the drive coils 14 during scanning of the field free line [0063-65]),
makes the detector detect the magnetization change (detecting magnetization response using receive coils 16 during movement of the field free lines [0065-67]),
generates projection data of the magnetization change based on a position of the linear zero magnetic field region in [[the]] a scanning direction of the linear zero magnetic field region and an angle of the linear zero magnetic field region in [[the]] a rotation direction of the linear zero magnetic field region (acquiring spatially dependent measurement date associated with positions of the field free line and using such data for tomographic reconstruction [0068-71], the field free region is moved along preselected multidirectional trajectories through the imaging volume [0062,77], such that the spatial configuration of the field free line varies as a function of trajectory direction. Because the orientation of the field free line relative to the subject changes when the applied magnetic fields are varied along different trajectory directions, the acquired measurements data are inherently indexed not only by linear position but also by the angular orientation of the field free line, thereby constituting projection data based on both position and angle),
generates corrected projection data by performing sensitivity correction on the projection data by using a system function previously acquired for each piece of projection data (acquiring a system function (system matrix) in advance and applying the system matrix within processing circuitry 30 to correct measured signals for system sensitivity during reconstruction (system matrix x) [0073-78]), data, wherein the system function is a deconvolution coefficient (magnetic particle imaging reconstruction requires knowledge of a system function describing the system response to a spatial distribution of magnetic particles, and that image reconstruction is performed by inverting the system function to recover the particle distribution from the measured signals [0007]. The measured MPI signal corresponds to the response of the imaging system to the spatial particle distribution and therefore represents a convolution of the system response with the particle distribution. Accordingly, inversion of the system function during reconstruction inherently corresponds to a deconvolution of the measured signal with the system response on order to recover the underlying particle distribution. Thus, Rahmer’s reconstruction process necessarily performs signal correction using a previously determined system function in a manner consistent with the claimed use of a deconvolution coefficient) and generates the magnetic nanoparticle image based on the corrected projection data (reconstructing the magnetic nanoparticle image using corrected signal data and the stored system matrix [0078-81]), and
Rahmer does not explicitly teach when generating the system function, the processing circuitry makes the linear zero magnetic field generation [[unit]] coil form the linear zero magnetic field region in a structure as the subject including the magnetic nanoparticles at a predetermined particle concentration and having a predetermined size and scan, rotate, or scan and rotate the linear zero magnetic field region,
makes the excitation magnetic field application [[unit]] coil apply the excitation magnetic field to a magnetic field region including the linear zero magnetic field region in the structure,
makes the detector detect the magnetization change in the structure, and
generates the system function in regard to each piece of projection data based on the magnetization change in the structure.
However Weber in a relevant art teaching MPI calibration and measurement volumes teaches when generating the system function, the processing circuitry makes the linear zero magnetic field generation [[unit]] coil form the linear zero magnetic field region in a structure as the subject including the magnetic nanoparticles at a predetermined particle concentration and having a predetermined size (a calibration structure containing magnetic nanoparticles of known concentration and geometry used during system calibration [0009, 0046])
and scan, rotate, or scan and rotate the linear zero magnetic field region (acquiring calibration signals while the field free region is moved relative to the calibration sample to obtain system response data at different spatial configurations [0005, 31]),
makes the excitation magnetic field application [[unit]] coil apply the excitation magnetic field to a magnetic field region including the linear zero magnetic field region in the structure (applying excitation magnetic fields during calibration measurements to excite magnetic nanoparticles within the calibration structure [0004-6, 0045]),
makes the detector detect the magnetization change in the structure (detecting magnetization response signals from the calibration sample during calibration measurements to generate the system matrix [0004-6, 46-48]), and
generates the system function in regard to each piece of projection data based on the magnetization change in the structure (generating and storing a system matrix (system function) for detected calibration signals for later use in image reconstruction [0046-48]).
It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention to generate the system function used in Rahmer using the calibration structure and calibration process taught by Weber, both directed to MPI systems employing system function based reconstruction for improving reconstruction accuracy and repeatability.
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Regarding claim 2, Rahmer as modified further teaches wherein in the scanning, the linear zero magnetic field generation [[unit]] coil linearly moves the linear zero magnetic field region in the scanning direction (the field free region (FFP, FFL) is shifted linearly along predefined spatial direction by controlling currents applied to the selection d, drive and focus field coils [0003-0004], deliberate FFP trajectories [0062] and changing position of sub zones by magnetic field superposition [0077] teaching movement of the FFP along a preselected trajectory) by a predetermined travel distance each time (the movement of the field free region is controlled according to predefined trajectories and positions, implying discreate predetermined spatial steps during scanning [0003-4] predefined trajectory covering the scanning volume [0099-101], shifting the system function according to known FFP positions corresponding to controlled movement. Because the field free region is moved according to known and preselected positions, the displacement between successive positions necessarily corresponds to a predetermined travel distance).
It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention to generate the system function used in Rahmer using the calibration structure and calibration process taught by Weber, both directed to MPI systems employing system function based reconstruction for improving reconstruction accuracy and repeatability.
Regarding claim 3, Rahmer as modified further teaches wherein the scanning direction is a direction orthogonal to a lengthwise direction of the linear zero magnetic field region([0003] a field free line as an alternative to field fee point, [0061] the spatial extent of the selection field defining the zero field region, [0062] teaches that additional magnetic fields are applied to change the position of the field free region, including shifting the region through the imaging volume, [0077] teaches movement of the field free. When the zero field is implemented as a linear field free line, shifting the field free region through the imaging volume inherently required movement in a direction transvers (orthogonal) to the lengthwise direction of the line in order to sample different spatial locations).
It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention to generate the system function used in Rahmer using the calibration structure and calibration process taught by Weber, both directed to MPI systems employing system function based reconstruction for improving reconstruction accuracy and repeatability.
Regarding claim 4, Rahmer as modified further teaches wherein in the rotation, the linear zero magnetic field generation [[unit]] coil rotates the linear zero magnetic field region (controlling the selection field and additional magnetic fields such that the orientation of the field free region changes over time as part of a predetermined trajectory used for image reconstruction, the field free region follows a deliberately selected trajectory through imaging volume [0003-4], superposition of magnetic fields may be used to change the position and configuration of the field free region [0062], the field free region moves along a preselected trajectory, which may include changes in direction as a function of time [0077]a linear field free region changing the direction of the applied magnetic fields necessarily results in a rotation of the orientation of the field free line within the imaging volumes ) by a predetermined rotation angle each time (the movement of the field free region is controlled according to predefined trajectories and parameters determined prior to imaging [0003-4] the preselected trajectory and movement).
It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention to generate the system function used in Rahmer using the calibration structure and calibration process taught by Weber, both directed to MPI systems employing system function based reconstruction for improving reconstruction accuracy and repeatability.
One of the ordinary skills in the art would have been motivated to make this modification selecting a specific rotation increment for successive orientations of the field free line constitutes a routine design choice based on the discloses framework of predetermined trajectories (Please see MPEP 2144 .04 VI.C.)
Regarding claims 5, 8, Rahmer further teaches wherein when generating the system function, the processing circuitry generates the system function representing detection sensitivity (MPI reconstruction relies on a system function (system matrix) that represents the sensitivity and spatial response of the MPI system to magnetic nano particles [0007-8], describing determination of the system function [0100-101] describing use of the system function to compensate for system response ) at each of combinations of the position and the angle (the system function as associated with known position of the field free region along a preselected trajectory, and that the system function may be shifted or adapted according to the spatial position of the field free region [0077], preselected trajectory, shifting the system function according to FFP [0100-010])
Rahmer does not explicitly teach stores a system function set including a plurality of the system functions in a storage device.
However, Weber in a relevant art teaching MPI calibration and measurement volumes teaches stores a system function set including a plurality of the system functions in a storage device (generating a system matrix composed of plurality of system response measurements, each corresponding to a different spatial position on a calibration sample, and storing that system matrix for subsequent image reconstruction, system matrix generation [0004-6, 46-48] storing columns of the system matrix).
It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention to generate the system function used in Rahmer using the calibration structure and calibration process taught by Weber, both directed to MPI systems employing system function based reconstruction for improving reconstruction accuracy and repeatability.
Regarding claim 6, Rahmer as modified further teaches wherein when generating the magnetic nanoparticle image, the processing circuitry generates the corrected projection data (during image reconstruction detected MPI signals are processed and corrected using previously acquired system response information prior to or as part of image generation [0005], reconstruction by computer using system function [0100-101]) by selecting the system function from the storage device (system function is acquired in advance and stored , and that the stored system function is accessed and used during reconstruction of imaging data[0007-8]) and performing the sensitivity correction on the projection data by using the selected system function ( the stored system function is used to compensate for system sensitivity and spatial response when reconstructing the magnetic nanoparticle distribution form measure signals [0007-8, 0100-101]).
It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention to generate the system function used in Rahmer using the calibration structure and calibration process taught by Weber, both directed to MPI systems employing system function based reconstruction for improving reconstruction accuracy and repeatability.
Regarding claim 9, the method recited is intrinsic to the apparatus recited in claim 1, as disclosed by Rahmer (U.S. Publication 20160216355) in view of Weber (U.S. Publication 20170020407) as the recited method steps will be performed during the normal operation of the apparatus, as discussed above with regard to claim 1.
Regarding claim 10, the structure recited is intrinsic to the method recited in claim 9, as disclosed by Rahmer (U.S. Publication 20160216355) in view of Weber (U.S. Publication 20170020407) as the recited structure will be used during the normal operation of the method, as discussed above with regard to claim 9.
Regarding claim 11-13, Rahmer does not explicitly teach wherein the deconvolution coefficient is a measurement magnetic particle imaging signal divided by an ideal magnetic particle imaging signal.
However, Weber in a relevant art teaching MPI calibration and measurement volumes teaches wherein the deconvolution coefficient is a measurement magnetic particle imaging signal divided by an ideal magnetic particle imaging signal (calibration signals are detected and used to create the system matrix used for reconstruction [0004-06,32] because the calibration measurements in Weber are performed using a known particle distribution, the resulting system response corresponds to the relationship between the measurement magnetic particle imaging signal and the ideal magnetic particle imaging signal corresponding to the known particle distribution).
It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention to generate the system function used in Rahmer using the calibration structure and calibration process taught by Weber, both directed to MPI systems employing system function based reconstruction for improving reconstruction accuracy and repeatability and would be obvious to further define the deconvolution coefficient in this manner as an explicit mathematical expression of the system response determined during calibration and used during reconstruction.
Regarding claim 14-16, Rahmer does not explicitly teach wherein when generating the system function, the processing circuitry generates the system function representing detection sensitivity at each of combinations of the position and the angle.
However, Weber in a relevant art teaching MPI calibration and measurement volumes teaches wherein when generating the system function, the processing circuitry generates the system function representing detection sensitivity at each of combinations of the position and the angle (a system matrix from calibration measurements performed at multiple spatial positions of a calibration sample, wherein calibration signals are detected and used to create the system matrix used for reconstruction [0004-6, 32], because the calibration measurements in Weber are performed at different spatial configurations of the magnetic particle sample relative to the field free region trajectory, the resulting system matrix represents detection sensitivity corresponding to different spatial positions and orientations of the field free region within the measurement volume).
It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention to generate the system function used in Rahmer using the calibration structure and calibration process taught by Weber, both directed to MPI systems employing system function based reconstruction for improving reconstruction accuracy and repeatability.
Allowable Subject Matter
Claim 7 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
None of the prior art of record discloses or teaches the claimed combinations, or feature the following:
Regarding claim 7, wherein when generating the magnetic nanoparticle image, the processing circuitry generates the corrected projection data by selecting the system function from the storage device, estimating a system function other than the selected system function by executing interpolation by using the selected system function, and performing the sensitivity correction on the projection data by using the selected system function and the estimated system function.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 TAQI R NASIR whose telephone number is (571)270-1425. The examiner can normally be reached 9AM-5PM EST M-F.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Lee Rodak can be reached at (571) 270-5628. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/TAQI R NASIR/Examiner, Art Unit 2858
/LEE E RODAK/Supervisory Patent Examiner, Art Unit 2858