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 .
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 13 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Shao (US Pub. No. 2007/0090298 A1).
With regards to claim 13, Shao discloses a calibration method comprising obtaining a plurality of items of detection data (S1, S2) each corresponding to a depth at which a gamma ray has caused an interaction in a plurality of DOI detectors; and calibrating the plurality of DOI detectors based on each of the obtained plurality of items of detection data and an ideal distribution of the plurality of items of detection data [0010], [0011].
Notice the computation R = S1/ (S1 + S2) and further the established dN/dx along the depth axis and the applied theory CDF of R while deriving of the DOI function x(R) and the calibration using the measured data in addition to the reference distribution [0010], [0011].
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) 1 is/are rejected under 35 U.S.C. 103 as being unpatentable over Shao (US Pub. No. 2007/0090298 A1) in view Cho et al. (US Pub. No. 2016/0299240 A1).
With regards to claim 1, Shao discloses method for calibrating three-dimensional PET detectors by applying probability techniques to the problem of calibration [0022]. Shao further teaches the method determines the depth-of-interaction function for PET detectors (Abstract). FIG. 2 schematically illustrates a first step, wherein detector crystal C is uniformly irradiated to have interactions uniformly distributed along the crystal depth (Z axis). Such a distribution may be provided by a uniform flood source 12 or even by a point source (not shown) at a sufficient distance from PET detector 10 to approximate a point source at infinite [0010], [0011], [0018], [0023] – [0027], [0037] – [0042].
Shao fails to expressly disclose that the calibration method is included in a pet apparatus comprising a processing circuitry configured with DOI detection data ideal distribution.
Cho relates to a setup of a pet detector (Abstract). FIG. 3 illustrates an example data acquisition setup using two SiPM detector units 201, 203, scintillator crystals 202, 204, communications path 211 for position and energy information, detector unit separate communications paths 207, 209 for timing, and the processing unit 111 [0005], [0018], [0035], [0036], [0038] – [0042], [0046], [0047].
In view of the utility, to include a processor configured to identify coincident events from the detector unit data and calculate operating parameters as needed for the detector units or scanner, 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.
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 a 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 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 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 a 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.
Conclusion
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/DJURA MALEVIC/Examiner, Art Unit 2884
/UZMA ALAM/Supervisory Patent Examiner, Art Unit 2884