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 Amendment
The amendment filed 06/10/2026 was entered. Claims 1-13 are currently pending. Claims 1, 7-9, and 13 are amended by the present amendment. The changes to the claims are supported by the originally filed specification and do not add new matter.
Response to Arguments
Regarding Applicant's detector-ring argument, Applicant is correct that Shao does not expressly disclose the newly added detector-ring limitation. For that reason, the prior §102 rejection of claim 13 over Shao alone is withdrawn. The argument does not establish patentability, however, because Cho '706 expressly teaches a PET detector array arranged in a ring surrounding the patient and expressly teaches DOI-capable PET detectors, Cho '706 [0045]-[0049], [0053], (Figure 3).
Regarding Applicant's asserted incompatibility between Shao and a detector-ring PET system, the argument is not persuasive because it treats Shao's Figure 2 external-irradiation embodiment as the only manner in which Shao's calibration principle can operate. Shao expressly teaches that internal background irradiation can provide initial calibration or recalibration without external uniform irradiation, Shao [0039]. Shao further addresses the situation after the detector is installed inside a PET system and it is not possible or practical to irradiate the crystal with a uniform external source; Shao then extends its calibration principle using detected interaction distributions and updated cumulative distribution functions, Shao [0040]-[0045]. Accordingly, the proposed combination does not require physically placing Shao's Figure 2 side-irradiation arrangement inside Cho '706's detector ring.
Regarding Applicant's argument that the secondary PET reference does not itself teach all of the obtaining and calibrating steps, the rejection does not rely on the secondary reference for those unchanged limitations. Shao remains relied upon for the DOI calibration teachings previously mapped, while Cho '706 is relied upon for the newly added ring-arranged DOI-detector architecture. The references are considered for what they collectively teach, rather than requiring each reference separately to contain the entire claim.
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 1 is rejected under 35 U.S.C. §103 as being unpatentable over Shao (US 2007/0090298 A1) in view of Cho et al. (US 2016/0299240 A1), hereinafter "Cho '240," and Cho (US 2013/0032706 A1), hereinafter "Cho '706."
With regard to claim 1, for the unamended limitations, refer to the rejection of claim 1 in the prior Office Action. The present discussion is limited to the newly added limitation, "a detector ring including a plurality of depth of interaction (DOI) detectors aligned on a circumference around a central axis."
Shao teaches practical three-dimensional PET detectors made from arrays of crystals, states that every individual crystal may be calibrated with the same setting and method, and expressly contemplates use, drift, and recalibration after the detector is installed in a PET system, Shao [0023]-[0024], [0038]-[0045].
Shao, however, does not expressly teach "a detector ring including a plurality of depth of interaction (DOI) detectors aligned on a circumference around a central axis" (that is, the newly claimed circumferential PET-ring architecture containing DOI-capable detectors).
Cho '706 teaches the missing limitation. Cho '706 describes PET coincidence detection using two opposing detectors of a ring of detectors, and further teaches a PET system 32 having a detector array 36 "arranged in a ring that surrounds a patient or subject," Cho '706 [0004], [0045], (Figure 3). Cho '706 further teaches that the PET detectors 44 of detector array 36 are DOI-capable: each scintillation crystal 46 may be configured to capture depth of interaction, including layered DOI structures, light-sharing DOI structures, or optical sensors at both ends of a scintillation crystal for determining DOI from compared signals, Cho '706 [0046]-[0049]. Cho '706 also teaches that detector array 36 may substantially surround the patient, Cho '706 [0053]. A detector array arranged as a ring around the subject necessarily forms the claimed circumferential arrangement around the ring's central opening/axis.
In view of the utility of arranging DOI-capable PET detectors in a ring around the imaging subject so that opposing detector pairs can acquire coincidence events while preserving DOI information, it would have been obvious to a person of ordinary skill in the art at the time the invention was made to implement Shao's DOI calibration teachings in the ring-arranged DOI PET architecture taught by Cho '706, while retaining the processor/calibration implementation previously supplied by Cho '240, thereby predictably providing practical DOI calibration in a conventional PET-ring environment.
Claim(s) 2 – 4 and 7 - 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Shao (US Pub. No. 2007/0090298 A1) and Cho et al. (US Pub. No. 2016/0299240 A1) in view of Cho (US Pub. No. 2013/0032706 A1), hereinbelow Cho 706’.
With regards to claim 2, Shao modified discloses the claimed invention according to claim 1, but fails to expressly disclose that the ideal distribution is a distribution that represents, in association with each other, a depth at which a gamma ray causes an interaction in each of the plurality of DOI detectors to be calibrated and a time difference among the plurality of DOI detectors acquiring corresponding items of detection data.
Cho 706’ discloses a time-of-flight compensation and pet system (Abstract). FIG. 3 shows system 30 including a PET system 32 and an optical configuration system 34 coupled to, and in communication with, the PET system 32. The PET system 32 is a PET imaging system, but may be or include a computer, workstation, database, server, or other system [0045].
Cho 706’ teaches pet detection with timing profiles, wherein the timing profile for each depth of interaction exhibits a distribution of photon arrival times. The distribution may have a Gaussian or near-Gaussian (e.g., parabolic-like) shape, which may follow from the random nature of the travel path of the visible photons between the interaction depth and the optical sensor [0037] – [0039]. Cho 706’ further discloses that the interaction depth effects the timing distribution (i.e., timing profiles) of detected events and that a time difference can be computed between a baseline profile and depth-specific timing profiles using there center points [0037] – [0039] (Figure 2).
In view of the utility, to improve coincidence timing resolution and reduce systematic timing bias, it would have been obvious to a person of ordinary skill in the art at the time of the invention to include in Shao the teachings such as that taught by Cho 706’.
With regards to claim 3, Shao modified discloses the claimed invention according to claim 2 but fails to expressly disclose that the ideal distribution is a distribution in which the time difference decreases as the depth increases.
Cho 706’ discloses the timing profile center shifts monotonically with interaction depth. The sign of “time difference” is a reference convention (baseline minus profile vs profile minus baseline), yielding a decreasing or increasing relationship depending on the underlying monotonic depth to time mapping [0041] – [0042].
In view of the utility, to improve coincidence timing resolution and reduces systematic timing bias, it would have been obvious to a person of ordinary skill in the art at the time of the invention to include in Shao the teachings such as that taught by Cho 706’.
With regards to claim 4, Shao modified discloses the claimed invention according to claim 2 and further DOI is determined using two photodetectors receiving light form the same interaction point (opposing ends), providing an opposing detector geometry [0010] – [0011].
With regards to claim 7, Shao modified discloses the processing circuitry is configured to correct the depth corresponding to each of the plurality of items of detection data in the plurality of DOI detectors to be calibrated to be close to the ideal distribution [0010], [0011].
With regards to claim 8, Shao modified discloses the claimed invention according to claim 7 but fails to disclose the processing circuitry is configured to correct, for each of the plurality of items of detection data, a time shift due to a difference in a rise time between output signals from the plurality of DOI detectors prior to the correcting based on the ideal distribution.
Cho expressly teaches performing a time-walk correction for each detected events using time-walk correction tables derived from timing histograms across multiple energy bands [0073], [0074]. Time-walk is a time shift error arising from pulse-shape differences in threshold-based timing extraction, i.e., leading-edge discriminators), which encompasses differences in rise behavior of detector output signal. Cho further teaches extracting pulse time marks using a timing discriminator and selecting threshold values to optimize timing resolution [0045] [0046].
Cho 706’ further discloses that the interaction depth effects the timing distribution (i.e., timing profiles) of detected events and that a time difference can be computed between a baseline profile and depth-specific timing profiles using there center points [0037] – [0039] (Figure 2).9. The PET apparatus according to claim 2, wherein the processing circuitry is configured to correct the time difference between the plurality of DOI detectors to be calibrated having acquired the detection data to be close to the ideal distribution.
In view of the utility, to improve coincidence timing resolution and reduces systematic timing bias, it would have been obvious to a person of ordinary skill in the art at the time of the invention to include in Shao the teachings such as that taught by Cho and Cho 706’.
With regards to claim 9, Shao modified discloses the claimed invention according to claim 7 but fails to disclose the processing circuitry is configured to correct a time difference between the plurality of DOI detectors to be calibrated having acquired the detection data to be close to the ideal distribution.
Cho teaches time-walk correction tables and timing-histogram centers are derived and used as correction values across energy band [0073] – [0074].
Cho 706’ teaches depth-dependent timing references that teaches correcting timing differences to match a reference and/or ideal timing relation [0037] – [0039].
In view of the utility, to improve timing resolution and reduces systematic timing bias as needed, it would have been obvious to a person of ordinary skill in the art at the time of the invention to include in Shao the teachings such as that taught by Cho and Cho 706’.
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Shao (US Pub. No. 2007/0090298 A1) and Cho et al. (US Pub. No. 2016/0299240 A1) in view of Cho (US Pub. No. 2013/0032706 A1), hereinbelow Cho 706’ in view of Van Eijk et al. (Inorganic scintillators in medical imaging; 2002 Phys. Med. Biol. 47 R85).
With regards to claim 5, Shao modified discloses the claimed invention according to claim 2, but fails to expressly disclose that the depth represents the ideal distribution is a depth at which a gamma ray made diagonally incident on a DOI detector adjacent to one of a pair of opposing DOI detectors causes an interaction.
Van Eijk teaches diagonal and/or oblique or angled incidence and adjacent crystal interactions for Pet, wherein of 511 KeV quanta hitting the detector at those angles, if quantum is not absorbed in the first crystal column encountered. As such, the quantum can traverse the detector and hit a neighboring column behind the entrance window at the least, causing a parallax error and more (5.2. PET-system requirements and sources of error; p R93-R95).
Van Ejik further teaches that efforts to introduce methods that give depth-of-interaction (DOI) information even more information and clarity as needed is important (5.2.3. Position resolution; p R95).
In view of the utility, to improve DOI by reducing parallax error as needed, it would have been obvious to a person of ordinary skill in the art at the time of the invention to include in Shao the teachings such as that taught by Van Ejik.
Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Shao (US Pub. No. 2007/0090298 A1) and Cho et al. (US Pub. No. 2016/0299240 A1) in view of Cho (US Pub. No. 2013/0032706 A1), hereinbelow Cho 706’ in view of McCroskey et al. (US Patent 6,072,177).
With regards to claim 6, Shao modified discloses the claimed invention according to claim 2 and further teaches using a predetermined and/or ideal depth distribution as a calibration target [0010], [0011] but fails to expressly disclose that combination of the depth represented by the ideal distribution includes both a depth at which a gamma ray that has been made incident on the plurality of DOI detectors causes an interaction and a depth at which a scattering gamma ray caused by Compton scattering of the incident gamma ray causes an interaction.
Cho teaches scattered events in Pet detectors includes Compton scattering effects where a 511 KeV photo’s energy may be split between detectors [0076]
Cho 706’ teaches that the interaction depth influences timing profiles and/or time offsets [0037] – [0039].
McCroskey teaches that an energy histogram includes a shape photopeak portion corresponding to the 511 KeV and a flatter portion attributed to Compton scattering (Col. 24, Lines 9 – 28) (Figure 10).
In view of the utility, to include Compton-scatter interactions depths in reference and/or ideal distributing used for calibration since such events are an expected component of PET detect data and accounting for them improves calibration robustness and accuracy, it would have been obvious to a person of ordinary skill in the art at the time of the invention to include in Shao already modified by Cho and Cho 706’ with the teachings such as that taught by McCroskey.
Claim(s) 10 - 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Shao (US Pub. No. 2007/0090298 A1) and Cho et al. (US Pub. No. 2016/0299240 A1) in view of Cho (US Pub. No. 2013/0032706 A1), hereinbelow Cho 706’ in view of Fujisawa et al. (JP 08-271241 A).
Notice that Fujisawa discloses a depth-dependent count and/or intensity relationship as followed, see the formulas below within attenuation coefficient of the gamma ray when considering the rejections of claims 10 – 12.
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With regards to claim 10, Shao modified discloses the claimed invention according to claim 1, and further teaches a PET detector calibration based on distributions of detected events corresponding to interaction locations along a depth axis of a scintillator detector [0025] – [0032].
Shao fails to expressly teach that the ideal distribution is a distribution that represents, in association with each other, a depth at which a gamma ray causes an interaction in each of the plurality of DOI detectors to be calibrated and a count of photons produced by the interaction with the gamma ray in each of the plurality of DOI detectors to be calibrated.
Fujisawa teaches, see Figure 1, intensity and/or count vs depth model [0010] – [0011].
Notice that where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable parts and/or optimum variables by routine experimentation. It would have been obvious to one having ordinary skill in the art at the time the invention was made to modify Shao to include the parameters and set up such as that taught by Fujisawa in order to improve the detection and further, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable general conditions involves only routine skill in the art.
With regards to claim 11, Shao modified discloses the claimed invention according to claim 10 and further teaches a PET detector calibration based on distributions of detected events corresponding to interaction locations along a depth axis of a scintillator detector [0025] – [0032].
Shao fails to expressly teach the ideal distribution is a distribution in which the count decreases as the depth increases.
Fujisawa teaches, see figure 1, that exponential attenuation decreases with increasing depth [0015] – [0016].
Notice that where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable parts and/or optimum variables by routine experimentation. It would have been obvious to one having ordinary skill in the art at the time the invention was made to modify Shao to include the parameters and set up such as that taught by Fujisawa in order to improve the detection and further, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable general conditions involves only routine skill in the art.
With regards to claim 12, Shao modified discloses the claimed invention according to claim 10 and further teaches a PET detector calibration based on distributions of detected events corresponding to interaction locations along a depth axis of a scintillator detector [0025] – [0032].
Shao fails to expressly teach the ideal distribution is a distribution that follows I=Io exp(-μt), where t denotes the depth, I denotes the count at the depth t, Io denotes the count in a vicinity of a surface of each of the plurality of the DOI detectors, and μ denotes an attenuation coefficient of the gamma ray in each of the plurality of DOI detectors.
Fujisawa teaches, see figure 1, explicit exponential form ad parameter meanings [0005], [0015] – [0016].
Notice that where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable parts and/or optimum variables by routine experimentation. It would have been obvious to one having ordinary skill in the art at the time the invention was made to modify Shao to include the parameters and set up such as that taught by Fujisawa in order to improve the detection and further, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable general conditions involves only routine skill in the art.
The claim would have been obvious because the technique for improving a particular class of devices was part of the ordinary capabilities of a person of ordinary skill in the art, in view of the teaching of the technique for improvement in other situations.
Claim 13 is rejected under 35 U.S.C. §103 as being unpatentable over Shao (US 2007/0090298 A1) in view of Cho (US 2013/0032706 A1), hereinafter "Cho '706."
With regard to claim 13, Shao teaches DOI calibration suitable for practical PET detectors and expressly teaches recalibration after a detector has been installed in a PET system, including circumstances in which external uniform irradiation is not possible or practical, Shao [0022]-[0024], [0038]-[0045].
Shao, however, does not expressly teach that the method is performed by a PET apparatus comprising "a detector ring including a plurality of depth of interaction (DOI) detectors aligned on a circumference around a central axis."
Cho '706 teaches a PET system 32 having a detector array 36 arranged in a ring surrounding a patient or subject, and teaches that the PET detectors 44 in the array are configured to obtain depth-of-interaction information, Cho '706 [0045]-[0049], [0053], (Figure 3). Thus, Cho '706 supplies the newly added PET-ring/DOI-detector environment while Shao supplies the previously mapped DOI calibration method.
In view of the utility of performing DOI calibration in the same ring-arranged DOI detector architecture used for PET acquisition, it would have been obvious to a person of ordinary skill in the art at the time the invention was made to perform Shao's DOI calibration method using the ring-arranged DOI-capable detector system taught by Cho '706, thereby predictably enabling calibration of DOI detectors in a practical PET scanner.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/DJURA MALEVIC/Examiner, Art Unit 2884
/UZMA ALAM/Supervisory Patent Examiner, Art Unit 2884
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