DETAILED ACTION
Response to Amendment
Receipt is acknowledged of the amendment filed 11/11/2025. Claims 1-2, 5-6, 8-12 and 14-22 are pending. Claims 3-4, 7, and 13 are canceled. Claims 8 and 12 were amended.
Claim 8 was amended to depend on claim 1 in response to incorporating subject matter from claim 7 into claim 1 and canceling claim 7.
The specification was objected in the Non-Final Rejection filed 8/11/2025, but this response does not appear to address the objection. The objection remains as outlined below. Please review the objection and amend the specification accordingly.
Response to Arguments
Applicant's arguments filed 11/11/2025 have been fully considered but they are not persuasive.
The previous rejection of claim 12 was made over Y. Terada et al. J. Mag. Res. 230 (2013) 125-133 (Terada) in view of Z. Ren et al. Progress In Electromagnetics Research M, Vol. 6, 23-34, 2009 (Ren) and Rimkunas et al. US 6,566,991 (Rimkunas).
Claim 12 was amended to recite, “iii) defining a distribution of correction elements comprising a predetermined number of magnetic dipoles made only of permanent magnets, each of the magnetic dipoles having a predetermined magnetic charge and a predetermined position relative to the magnetic structure generating the magnetic field;”.
The applicant amended claim 12 to specify the magnetic dipoles are “made only of permanent magnets,”. This implies the method of claim 12 comprises only passive shimming and not active shimming.
In the Response to Arguments section of the Non-Final Rejection filed 8/11/2025, the examiner expressed the limitations as claimed would be obvious to one of ordinary skill in the art (see page 3, paragraphs 12-13).
In paragraph 12 on page 3, the examiner expressed the pending claims “are not limited to ‘the use only of ‘passive shimming’’”. The current amendments now specify shimming is performed using only permanent magnets and, therefore, overcomes that argument.
In paragraph 13 on page 3, the examiner argued:
Second, the pending application teaches in [0122] of the specification as filed 9/9/2022, “Fig. 7 shows a block diagram of a high-level embodiment of the generic embodiment of Fig. 2. In this embodiment, the magnetic unit 100 includes …at least one compensation coil 12…” and in [0124] “The thermal and magnetic control unit also controls the compensation coil 13 to correct the static magnetic field with reference to the variations induced therein by external magnetic fields and based on the actual field values detected by the magnetic field sensors 17.” (Note in [0124], the compensation coil 13 should be corrected to recite “the compensation coil 12”, see objection to the specification). Therefore, the pending application supports both active and passive shimming. It is illogical to conclude Terada’s teaching of passive and active shimming “teaches away” when the pending application teaches “a high-level embodiment” incorporating active shimming.
Applicant argues on pages 17-18 of arguments, “Applicant submits that the above-mentioned compensation coil 12 is a compensation coil which is controlled for generating a magnetic compensation field of external magnetic noise-fields permeating inside the gantry.” As best understood by the examiner, the compensation coil compensates for inhomogeneities in the coil, but it is not immediately clear to the examiner how the compensation coil compensates for inhomogeneities from noise without also compensating for inhomogeneities inherent to the magnet. In order to advance prosecution, the examiner will assume, arguendo, that the compensation coil 12 only compensates for noise and does not shim the magnet.
However, the examiner maintains the amendment still does not place claim 12 in condition of allowance since using only passive shimming is routine/obvious to one of ordinary skill in the art for reasons outlined in paragraph 14 on pages 3-4 of the Non-Final Rejection filed 8/11/2025 which were not addressed in the pending response to arguments.
It is well-understood by ordinary skill in the art that shimming is conventionally performed using active and/or passive shimming. Further, it would be common sense for one of ordinary skill in the art that if passive shimming achieves a desired homogeneity, active shimming would no longer be necessary. Further support for this position may be found in:
Previously cited reference US 2017/0299674 teaches wherein a passive shim method may be combined with an active shimming process, or without an “active” apparatus. See [0011], “The passive shim systems and processes disclosed herein combine the best properties of active and passive shimming approaches. Like traditional passive shims, the present systems can be used without the need for sources of electrical current or other “active” apparatus, so that the inventive methods and apparatus can require no power and the overall device containing the magnet does not require high-precision active shim control apparatus, which may be complicated or bulky.”
Previously cited reference 6,634,088 teaches wherein active and passive shimming methods are known, and active shimming “adds expense and complexity to the overall MRI system” and overcomes the “disadvantages of the active (coil) shimming process, the present invention eliminates or minimizes the use of some or all shim coils and their associated currents altogether, achieving a high degree of field uniformity required for high resolution imaging through a process using only passive shimming.” See col. 1, line 25-col. 2, line 65.
Therefore, the examiner maintains it would be obvious to one of ordinary skill in the art to perform shimming using active shimming and/or passive shimming. Limiting the shimming to only passive shimming using permanent magnets would be an obvious matter of design choice for one of ordinary skill in the art if the passive shimming achieves acceptable results and would provide the advantage of a passive shim method without the need for sources of electrical current or other active apparatus which adds expense and complexity to the overall MRI system.
Therefore, claim 12 stands rejected as outlined below.
Specification
The disclosure is objected to because of the following informalities:
In [0124] of the specification, please correct “compensation coil 13” to recite - - compensation coil 12 - - in agreement with [0122]. Please review the spec to see if any similar corrections are required.
Appropriate correction is required.
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) 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Y. Terada et al. J. Mag. Res. 230 (2013) 125-133 (Terada) in view of Z. Ren et al. Progress In Electromagnetics Research M, Vol. 6, 23-34, 2009 (Ren) and US 2017/0299674 (McDowell).
Regarding claims 12, Terada teaches a method for shimming a magnetic field which is generated by a magnetic structure, and which permeates a volume of space, (a method for shimming a magnetic field in an imaging volume of an MRI permanent magnet; see Fig. 1) the method comprising:
i) measuring the magnetic field in a predetermined region of a volume of space permeated by the magnetic field (the magnetic field is measured over a three-axis grid in the target region of interest for shimming; see section 2.4);
ii) determining at least a parameter which is a measure of the homogeneity of the magnetic field (the RMS of ΔB0 corresponds to a measure of the homogeneity; see section 2.5);
iii) defining a distribution of correction elements comprising a predetermined number of magnetic dipoles, each of the magnetic dipoles having a predetermined magnetic charge and a predetermined position relative to the magnetic structure generating the magnetic field (the position and number of different size pole pieces were determined to minimize the homogeneity of the magnetic field; see section 2.5; Further details of determining the position may be found in Ren which corresponds to ref. [29] of Terada);
iv) calculating the charges of each of the dipoles and the position of each of the dipoles of a distribution which minimizes the parameter being a measure of the homogeneity of the magnetic field (the position and number of different size pole pieces were determined to minimize the homogeneity of the magnetic field; see section 2.5; Further details of determining the position may be found in Ren which corresponds to ref. [29] of Terada);
v) reconstructing a virtual representation of the magnetic structure and of the dipoles placed on the magnetic structure and displaying the virtual representation as one or more images (Fig. (a) would reasonably be interpreted as a virtual representation of the magnetic structure and dipoles);
vi) defining at least a plane crossing the volume of space permeated by the magnetic field and generating a graphical representation of the magnetic field intensity map on the plane related to the addition of the magnetic field of the magnetic structure to which the magnetic field of the calculated distribution of dipoles is added (spatial maps of the homogeneity on a plane is shown in Fig. 2(d) and (e));
vii) optionally repeating iv) to v) by using, as a starting distribution of dipoles, the dipoles calculated in the previous minimization step of the parameter measuring the magnetic field homogeneity and by refreshing the images generated and displayed at steps v) and vi) using the new calculated distribution of dipoles; and
viii) ending the repetition at a certain number of repetition steps or and/or when the parameter describing the field homogeneity has reached a predefined threshold and using the distribution of dipoles calculated by the last repletion step as the shimming distribution of dipoles to be positioned on the magnetic structure (since vii) recites “optionally repeating”, this would necessitate step viii) which determines when to end the repetition would also be optional.).
Terada fails to teach i) measuring the magnetic field at points of a grid of points along a closed surface enclosing the target region, and iii) defining a distribution of correction elements comprising a predetermined number of magnetic dipoles made only of permanent magnets.
Ren teaches i) measuring the magnetic field at points of a grid of points along a closed surface enclosing the target region (According to the properties of the harmonic function, the maximum and minimum of the function are all located on the boundary of the region. Thus the practical target area on which the homogeneity of magnetic field has to be checked is reduced and restricted onto the boundary of the region, the surface of the sphere. After the main magnet is assembled, the magnetic field on the spherical surface of the imaging region is measured firstly. See section “FORMULATION OF THE METHOD PROPOSED” on pages 25-26.)
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the features as taught in Ren into Terada in order to gain the advantage of only measuring points on the surface of a volume of interest since the maximum and minimum of the function are all located on the boundary of the region due to the magnetic potential satisfying the Laplace equation.
McDowell teaches iii) defining a distribution of correction elements comprising a predetermined number of magnetic dipoles made only of permanent magnets (a passive shimming method may be used without the need for an “active” shim coil apparatus or combined with active shimming methods and structures; see [0011], [0096], [0101]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the features as taught in McDowell into Terada in order to gain the advantage of shimming a magnet using only passive shims without the need for sources of electrical current or other “active” apparatus so that the apparatus can require no power and the overall device containing the magnet does not require high-precision active shim control apparatus, which may be complicated and bulky and add cost and complexity to the system.
Allowable Subject Matter
Claims 1-2, 5-6, 8-11, and 14-22 are allowed.
Regarding claims 1 and 5, the prior art of record fails to teach or suggest defining a second three-dimensional closed boundary surface enclosing a part of the volume of space permeated by the magnetic field, the second three-dimensional surface having a different shape than the first three-dimensional closed boundary surface and the volume of space enclosed by the two boundary surfaces being at least partly coincident one with the other; - the second three-dimensional closed boundary surface enclosing a part of the volume of space permeated by the magnetic field coinciding with the part of a target body which is represented and visible in an image of the target body; - numerically evaluating the magnetic field in the part of the volume of space inside the second three-dimensional closed boundary surface by applying a field expansion equation; - calculating from the numerical evaluation of the magnetic field the homogeneity variations of the magnetic field for each iteration of the step d); and - carrying out the step d) to h), in combination with all other limitations of claims 1 and 5, respectively.
Claims 2, 6-11, and 14-22, definite and enabled by the specification, are allowed through a dependence on one of allowed claims 1 and 5.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. See PTO-892.
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 STEVEN LEE YENINAS whose telephone number is (571)270-0372. The examiner can normally be reached M - F 10 - 6.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Judy Nguyen can be reached on (571) 272-2258. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/STEVEN L YENINAS/Primary Examiner, Art Unit 2858