US 12171593

Here's a concise summary of US patent 12171593:

Title: Methods and systems for retrospective internal gating

Assignee: Memorial Sloan Kettering Cancer Center

Inventors: Adam L. Kesner

Filing Date: June 8, 2022 (based on Application number US17/835,509)

Issue Date: December 24, 2024

Abstract: The invention describes a method for deriving respiratory gated PET image reconstruction from raw PET data. It uses respiratory motion information, which is extracted from fluctuations in individual voxel signals, to generate usable respiratory phase information. This method enables the reconstruction of respiratory-gated PET images from PET data automatically and without the need for external hardware.

Plain-Language Overview of Independent Claims:

• Claim 1 (Method for retrospective internal gating): This claim describes a method that involves:

  1. Acquiring image data: Obtaining a series of digital images (i1 to in) over time, which contain cyclical signals related to the periodic motion of an object.
  2. Extracting information: Getting data from multiple arrays (corresponding to voxels) within these images.
  3. Generating a time-varying object motion function: Creating a function that describes the object's motion over time, using the extracted voxel information.
  4. Determining phase information: Using the motion function to figure out the different phases of the object's periodic motion (e.g., different stages of a breath cycle).
  5. Generating a corrected image: Creating at least one image that accounts for and corrects the periodic motion, by using the original image data and the determined motion phase information.

• Claim 19 (Non-transitory computer-readable medium): This claim describes a computer-readable medium (like a hard drive or flash drive) that stores a program. When a processor runs this program, it performs the same steps as described in Claim 1: acquiring image data, extracting voxel information, generating a time-varying object motion function, determining phase information, and generating a motion-corrected image.

• Claim 20 (System): This claim describes a system that includes one or more processors and a non-transitory computer-readable medium. The medium has instructions that, when executed by the processors, cause the system to perform the same steps as described in Claim 1: acquiring image data, extracting voxel information, generating a time-varying object motion function, determining phase information, and generating a motion-corrected image.

CAFC 2026 Dockets:
As of April 26, 2026, a search of CAFC 2026 dockets for US patent 12171593 did not yield any specific results indicating its presence in active litigation. The search results provided general information about CAFC cases in 2026 but did not mention patent 12171593. Therefore, I do not have authoritative information to confirm any ongoing legal challenges related to this specific patent in the CAFC dockets for 2026.

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The user is asking for known litigation involving US patent 12171593. I need to search for this patent number on litigation tracking sites like Unified Patents. I will extract the requested information for each case found: plaintiff(s), defendant(s), jurisdiction, case number, filing date, and outcome or current status. If no litigation is found, I will state that.

My previous search on CAFC dockets for 2026 did not yield specific results for this patent. I need to broaden my search to general patent litigation databases.As of April 26, 2026, a search for litigation involving US patent 12171593 on Unified Patents and general patent litigation sources did not yield any specific active or past litigation cases. Therefore, no known litigation for US patent 12171593 can be reported at this time.

Proceedings overview

There is no PTAB activity on file for US patent 12171593.

Strategic summary

As of today, 2026-06-02, there are no Inter Partes Review (IPR), Post-Grant Review (PGR), or Covered Business Method (CBM) proceedings on file for US patent 12171593 in the USPTO Open Data Portal. This means all claims of US12171593 are currently untested by AIA trial proceedings.

The absence of PTAB activity suggests that the patent has not yet been challenged through these administrative processes. For a potential defendant, this implies that the full range of prior art grounds under § 102 and § 103 (for IPR) or additional grounds under § 112 (for PGR/CBM) remains available for a potential petition, assuming statutory deadlines and other requirements are met.

Recommended next steps

Since no PTAB activity exists for US patent 12171593, a potential defendant has a clear path to file an AIA trial petition if they choose to challenge the patent's validity. This absence of prior challenges can be a significant factor, as well-asserted patents often become targets for IPRs.

Inventors

• Adam L. Kesner (Memorial Sloan Kettering Cancer Center)

Original assignee

Memorial Sloan Kettering Cancer Center is a hospital and cancer treatment/research institution. They likely use or embody the claims in their medical imaging and research practices. Their primary line of business is patient care and medical research. Memorial Sloan Kettering Cancer Center is currently operating.

Assignment timeline

• 2017-05-30 (executed) / recorded 2024-05-30 — Reel 067574/0953
  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: KESNER, ADAM
  • Assignee: MEMORIAL SLOAN KETTERING CANCER CENTER, NEW YORK
  • Correspondent: NOT LISTED
  • Context: Internal transfer from inventor to original assignee

There are no other recorded assignments for US patent 12171593 on the USPTO Assignment Center as of 2026-06-02.

Timeline diagram

timeline
    title Ownership of US 12171593
    2007 : Priority date
    2022 : Application filed by Memorial Sloan Kettering Cancer Center
    2024 : Issued to Memorial Sloan Kettering Cancer Center
         : Inventor assigned to Memorial Sloan Kettering Cancer Center

NPE / troll-pattern signals

1. Shell-entity transfer — not present (The only assignment is from the inventor to Memorial Sloan Kettering Cancer Center, an operating entity.)
2. Known asserter in the chain — not present (Memorial Sloan Kettering Cancer Center is not a known asserter.)
3. Repeat correspondent across the chain — not present (Only one assignment is recorded, and no correspondent information is explicitly listed on the Google Patents record for this assignment.)
4. Cascading transfers — not present (Only one assignment is recorded.)
5. Pre-litigation transfer — not present (No litigation is recorded for this patent as of 2026-06-02, and the assignment date does not align with any pre-litigation window.)
6. Bankruptcy fire-sale — not present (No indication of bankruptcy for Memorial Sloan Kettering Cancer Center.)
7. Privateering — not present (No evidence of privateering activity.)
8. Defensive aggregator (anti-NPE) — not present (The patent is currently assigned to Memorial Sloan Kettering Cancer Center, not a defensive aggregator.)

Verdict

Insufficient data (The only recorded assignment is from the inventor to the original assignee, Memorial Sloan Kettering Cancer Center, which is an operating entity. There are no other assignments or indications of NPE activity in the available records.)

Verification: https://assignmentcenter.uspto.gov/ (Search for patent number US12171593).

To identify the most relevant prior art for US patent 12171593, I will examine the patent citations listed within its document. The USPTO's Patent Public Search tool and Google Patents are reliable sources for this information.

Based on the provided patent text, US patent 12171593 lists several "Patent Citations." These are typically references considered by the examiner during the prosecution of the patent application and represent relevant prior art.

Here's an analysis of the patent citations to identify the most relevant prior art:

Patent Citations for US12171593B2:

The patent 12171593B2 explicitly lists the following "Patent Citations" and "Non-Patent Citations". I will focus on the patent citations as requested.

1. US6298260B1 - Respiration responsive gating means and apparatus and methods using the same

• Full Citation: US6298260B1
• Publication Date: 2001-10-02
• Priority Date: 1998-02-25
• Assignee: St. Jude Children's Research Hospital
• Brief Description: This patent describes respiration-responsive gating for medical imaging, particularly for reducing motion artifacts. It involves detecting respiratory movement and using that information to gate image acquisition or reconstruction.
• Potential Anticipated Claim(s): This patent potentially anticipates elements of Claim 1, particularly "acquiring image data corresponding to successive digital images... with temporally cyclical signals corresponding to periodic motion of a moving object," "determining, based on the time varying object motion function, phase information for the periodic motion," and "generating at least one image correcting for the periodic motion... based on the acquired image data and the determined phase information," as it deals with respiration-responsive gating to correct for motion.

2. US6144874A - Respiratory gating method for MR imaging

• Full Citation: US6144874A
• Publication Date: 2000-11-07
• Priority Date: 1998-10-15
• Assignee: General Electric Company
• Brief Description: This patent focuses on a respiratory gating method specifically for MR imaging. It aims to reduce motion artifacts caused by respiration during MR scans.
• Potential Anticipated Claim(s): Similar to US6298260B1, this patent could anticipate aspects of Claim 1 related to acquiring image data with cyclical signals corresponding to periodic motion and correcting for that motion using gating, but specifically within the context of MRI.

3. US6556695B1 - Method for producing high resolution real-time images, of structure and function during medical procedures

• Full Citation: US6556695B1
• Publication Date: 2003-04-29
• Priority Date: 1999-02-05
• Assignee: Mayo Foundation For Medical Education And Research
• Brief Description: This patent describes methods for producing high-resolution real-time images during medical procedures, which could involve accounting for motion to maintain image quality.
• Potential Anticipated Claim(s): While broader, it could potentially anticipate the general concept of "generating at least one image correcting for the periodic motion" within Claim 1 if the described methods involve motion correction through gating or similar techniques based on periodic physiological signals.

4. US6501981B1 - Apparatus and method for compensating for respiratory and patient motions during treatment

• Full Citation: US6501981B1
• Publication Date: 2002-12-31
• Priority Date: 1999-03-16
• Assignee: Accuray, Inc.
• Brief Description: This patent describes an apparatus and method for compensating for respiratory and patient motions during medical treatment, particularly in the context of radiation therapy.
• Potential Anticipated Claim(s): This patent directly addresses compensating for respiratory and patient motion, making it highly relevant to Claim 1's steps of acquiring image data, identifying periodic motion, and correcting for it.

5. US6539074B1 - Reconstruction of multislice tomographic images from four-dimensional data

• Full Citation: US6539074B1
• Publication Date: 2003-03-25
• Priority Date: 2000-08-25
• Assignee: General Electric Company
• Brief Description: This patent focuses on reconstructing multislice tomographic images from four-dimensional data, which often includes a temporal dimension to account for motion.
• Potential Anticipated Claim(s): This could potentially anticipate aspects of Claim 1 related to acquiring successive images over time and generating corrected images, especially if the four-dimensional data inherently incorporates or allows for the derivation of motion phase information for correction.

6. US7734078B2 - System and method for generating composite substraction images for magnetic resonance imaging

• Full Citation: US7734078B2
• Publication Date: 2010-06-08
• Priority Date: 2002-09-18
• Assignee: Cornell Research Foundation, Inc.
• Brief Description: This patent describes generating composite subtraction images for MRI, which can be used to visualize changes over time or remove static background, implicitly dealing with motion management.
• Potential Anticipated Claim(s): While not directly about "gating," the concept of generating composite images that account for changes (which could be motion-induced) might touch upon the broader idea of "generating at least one image correcting for the periodic motion" in Claim 1.

7. US20040218794A1 - Method for processing perfusion images

• Full Citation: US20040218794A1
• Publication Date: 2004-11-04
• Priority Date: 2003-05-01
• Assignee: Yi-Hsuan Kao
• Brief Description: This patent describes a method for processing perfusion images, which often involves dynamic imaging and thus may implicitly handle motion, though not explicitly retrospective internal gating.
• Potential Anticipated Claim(s): This patent might anticipate the step of "acquiring image data corresponding to successive digital images" if it involves time-series image acquisition. The connection to motion correction might be less direct compared to other citations.

8. US7359535B2 - Systems and methods for retrospective internal gating

• Full Citation: US7359535B2
• Publication Date: 2008-04-15
• Priority Date: 2003-06-20
• Assignee: Ge Medical Systems Global Technology Company, Llc
• Brief Description: This patent explicitly refers to "Systems and methods for retrospective internal gating," directly aligning with the title and subject matter of US12171593. It would describe techniques for internal gating based on acquired image data.
• Potential Anticipated Claim(s): This is a highly relevant prior art. It could potentially anticipate significant portions of Claim 1, including "acquiring image data," "extracting information for a plurality of arrays," "generating a time varying object motion function," "determining... phase information," and "generating at least one image correcting for the periodic motion." The key would be the specific mechanisms described for internal gating and how they compare to the voxel-based signal fluctuation analysis in US12171593.

9. US20050123183A1 - Data driven motion correction for nuclear imaging

• Full Citation: US20050123183A1
• Publication Date: 2005-06-09
• Priority Date: 2003-09-02
• Assignee: Paul Schleyer
• Brief Description: This patent application describes data-driven motion correction for nuclear imaging, which aligns with the PET imaging context mentioned in the abstract of US12171593.
• Potential Anticipated Claim(s): This is also highly relevant. It could potentially anticipate parts of Claim 1, especially concerning "acquiring image data" (for nuclear imaging), "extracting information for a plurality of arrays" (from image data), and "generating at least one image correcting for the periodic motion" using a data-driven approach.

10. US7756307B2 - Method of, and software for, conducting motion correction for a tomographic scanner

• Full Citation: US7756307B2
• Publication Date: 2010-07-13
• Priority Date: 2003-10-17
• Assignee: Hammersmith Imanet Limited
• Brief Description: This patent describes a method and software for motion correction in tomographic scanners.
• Potential Anticipated Claim(s): This patent is very relevant to the core of Claim 1, particularly the steps of "acquiring image data," "generating a time varying object motion function," and "generating at least one image correcting for the periodic motion" within the context of tomographic imaging. It could also be highly relevant to Claim 19 (computer-readable medium) and Claim 20 (system) given its focus on software for motion correction.

11. US7574249B2 - Device-less gating of physiological movement for improved image detection

• Full Citation: US7574249B2
• Publication Date: 2009-08-11
• Priority Date: 2005-02-08
• Assignee: General Electric Company
• Brief Description: This patent describes "device-less gating of physiological movement," directly addressing the goal of US12171593 to avoid external hardware. It would likely use internal image information for gating.
• Potential Anticipated Claim(s): This is another highly relevant prior art. It could potentially anticipate the essence of Claim 1, especially the concept of retrospective internal gating without external devices, and the steps of deriving motion information from image data to correct for periodic motion.

12. US20070081704A1 - System, program product, and methods for attenuation correction of emission data on PET/CT and SPECT/CT

• Full Citation: US20070081704A1
• Publication Date: 2007-04-12
• Priority Date: 2005-03-17
• Assignee: The University Of Texas System
• Brief Description: This patent application describes attenuation correction for emission data in PET/CT and SPECT/CT. While not directly about motion gating, accurate attenuation correction can be impacted by motion, so techniques might implicitly consider or manage motion effects.
• Potential Anticipated Claim(s): This patent's relevance might be more indirect, potentially anticipating the "acquiring image data" step if it involves PET data. Its direct anticipation of the motion gating and correction steps of Claim 1 is less certain without more detailed analysis of its specific methods for handling motion-related attenuation issues.

13. US20080226149A1 - Motion Compensation in Functional Imaging

• Full Citation: US20080226149A1
• Publication Date: 2008-09-18
• Priority Date: 2005-08-04
• Assignee: Hans-Aloys Wischmann
• Brief Description: This patent application addresses motion compensation in functional imaging, a broad category that includes PET.
• Potential Anticipated Claim(s): This is relevant to the general concept of motion correction in imaging and could anticipate aspects of Claim 1 regarding "acquiring image data," "extracting information," and "generating at least one image correcting for the periodic motion." The specifics of the motion compensation method would determine the directness of anticipation.

14. US20070127797A1 - Methods and systems to facilitate reducing banding artifacts in images

• Full Citation: US20070127797A1
• Publication Date: 2007-06-07
• Priority Date: 2005-11-23
• Assignee: General Electric Company
• Brief Description: This patent application focuses on reducing banding artifacts in images. While banding artifacts can be motion-related, the primary focus might not be general retrospective internal gating.
• Potential Anticipated Claim(s): The direct anticipation of Claim 1's steps related to retrospective internal gating based on cyclical signals might be limited unless the method for reducing banding artifacts explicitly involves deriving and using periodic motion information for correction.

15. US20070237372A1 - Cross-time and cross-modality inspection for medical image diagnosis

• Full Citation: US20070237372A1
• Publication Date: 2007-10-11
• Priority Date: 2005-12-29
• Assignee: Shoupu Chen
• Brief Description: This patent application deals with cross-time and cross-modality inspection for medical image diagnosis. While it involves comparing images over time, it's not explicitly about motion gating for image correction.
• Potential Anticipated Claim(s): This patent might broadly anticipate "acquiring image data corresponding to successive digital images" in Claim 1. However, its direct relevance to the specific internal gating and motion correction methodology of US12171593 is likely low.

16. US20090290774A1 - Dynamic computed tomography imaging

• Full Citation: US20090290774A1
• Publication Date: 2009-11-26
• Priority Date: 2006-05-26
• Assignee: Koninklijke Philips Electronics N. V.
• Brief Description: This patent application describes dynamic computed tomography imaging, which by its nature involves acquiring images over time to capture changes, including motion.
• Potential Anticipated Claim(s): This could potentially anticipate the "acquiring image data corresponding to successive digital images" step of Claim 1, especially in the context of CT. The specific method for handling motion within the dynamic imaging would determine its further relevance to other steps of Claim 1.

17. US20080253636A1 - Respiratory motion extraction from tomographic projection and image data

• Full Citation: US20080253636A1
• Publication Date: 2008-10-16
• Priority Date: 2007-04-11
• Assignee: Deller Timothy W
• Brief Description: This patent application specifically describes "respiratory motion extraction from tomographic projection and image data," which is very similar to the core idea of US12171593.
• Potential Anticipated Claim(s): This is highly relevant prior art and could potentially anticipate several steps of Claim 1, including "extracting information for a plurality of arrays" (from tomographic data), "generating a time varying object motion function" (based on extracted respiratory motion), and "determining... phase information."

18. US8229187B2 - Respiratory motion extraction from tomographic projection and image data

• Full Citation: US8229187B2
• Publication Date: 2012-07-24
• Priority Date: 2007-04-11
• Assignee: General Electric Company
• Brief Description: This is a granted patent stemming from the same priority date as US20080253636A1, also focused on respiratory motion extraction from tomographic data.
• Potential Anticipated Claim(s): As a granted patent covering the same subject matter as a highly relevant application (US20080253636A1), this is also highly relevant and could potentially anticipate several steps of Claim 1, particularly those related to extracting respiratory motion signals from image data and using them for motion correction.

19. US9814431B2 - Methods and systems for retrospective internal gating

• Full Citation: US9814431B2
• Publication Date: 2017-11-14
• Priority Date: 2007-05-04
• Assignee: Memorial Sloan Kettering Cancer Center
• Brief Description: This patent shares the exact same title ("Methods and systems for retrospective internal gating") and assignee as US12171593. It also shares the same priority date of 2007-05-04. The description of US12171593 states it is a continuation of several applications, including U.S. patent application Ser. No. 12/151,121, filed May 5, 2008 (now U.S. Pat. No. 9,814,431), which claims priority to U.S. Provisional Patent Application 60/916,200, filed May 4, 2007. This means US9814431B2 is a direct parent patent in the same patent family as US12171593.
• Potential Anticipated Claim(s): This patent is essentially the foundational patent for US12171593 within the same family. Therefore, it would directly anticipate all claims of US12171593 under 35 U.S.C. § 102 as it discloses the same invention with an earlier publication or priority date. The claims of US12171593 would likely represent specific refinements or variations of the methods and systems described in US9814431B2, or be continuations of the same subject matter.

Given that US12171593B2 is a continuation of US9814431B2, the latter is the most relevant prior art as it describes the same invention with an earlier priority date.

20. US10117625B2 - Methods and systems for retrospective internal gating

• Full Citation: US10117625B2
• Publication Date: 2018-11-06
• Priority Date: 2007-05-04
• Assignee: Memorial Sloan Kettering Cancer Center
• Brief Description: This patent also shares the exact same title and assignee as US12171593 and the same priority date of 2007-05-04. The description of US12171593 states it is a continuation of U.S. patent application Ser. No. 15/728,373, filed Oct. 9, 2017 (now U.S. Pat. No. 10,117,625). This confirms it is another direct parent patent in the same patent family.
• Potential Anticipated Claim(s): Similar to US9814431B2, this patent is a direct parent and would anticipate all claims of US12171593 under 35 U.S.C. § 102 as it discloses the same invention with an earlier publication or priority date.

21. US10448903B2 - Methods and systems for retrospective internal gating

• Full Citation: US10448903B2
• Publication Date: 2019-10-22
• Priority Date: 2007-05-04
• Assignee: Memorial Sloan Kettering Cancer Center
• Brief Description: This patent also shares the exact same title and assignee as US12171593 and the same priority date of 2007-05-04. The description of US12171593 states it is a continuation of U.S. patent application Ser. No. 16/178,332, filed Nov. 1, 2018 (now U.S. Pat. No. 10,448,903). This confirms it is another direct parent patent in the same patent family.
• Potential Anticipated Claim(s): Similar to US9814431B2 and US10117625B2, this patent is a direct parent and would anticipate all claims of US12171593 under 35 U.S.C. § 102 as it discloses the same invention with an earlier publication or priority date.

22. US10863950B2 - Methods and systems for retrospective internal gating

• Full Citation: US10863950B2
• Publication Date: 2020-12-15
• Priority Date: 2007-05-04
• Assignee: Memorial Sloan Kettering Cancer Center
• Brief Description: This patent also shares the exact same title and assignee as US12171593 and the same priority date of 2007-05-04. The description of US12171593 states it is a continuation of U.S. patent application Ser. No. 16/395,201, filed Apr. 25, 2019 (now U.S. Pat. No. 10,863,950). This confirms it is another direct parent patent in the same patent family.
• Potential Anticipated Claim(s): Similar to the other direct parent patents, this patent would anticipate all claims of US12171593 under 35 U.S.C. § 102 as it discloses the same invention with an earlier publication or priority date.

23. US11369322B2 - Methods and systems for retrospective internal gating

• Full Citation: US11369322B2
• Publication Date: 2022-06-28
• Priority Date: 2007-05-04
• Assignee: Memorial Sloan Kettering Cancer Center
• Brief Description: This patent also shares the exact same title and assignee as US12171593 and the same priority date of 2007-05-04. The description of US12171593 states it is a continuation of U.S. patent application Ser. No. 17/120,579, filed Dec. 14, 2020 (now U.S. Pat. No. 11,369,322). This confirms it is another direct parent patent in the same patent family.
• Potential Anticipated Claim(s): Similar to the other direct parent patents, this patent would anticipate all claims of US12171593 under 35 U.S.C. § 102 as it discloses the same invention with an earlier publication or priority date.

24. US20100183206A1 - Adjusting acquisition protocols for dynamic medical imaging using dynamic models

• Full Citation: US20100183206A1
• Publication Date: 2010-07-22
• Priority Date: 2007-06-21
• Assignee: Koninklijke Philips Electronics N.V.
• Brief Description: This patent application describes adjusting acquisition protocols for dynamic medical imaging using dynamic models. This is related to managing time-varying data in medical imaging.
• Potential Anticipated Claim(s): This could broadly anticipate "acquiring image data corresponding to successive digital images" (dynamic imaging) and possibly the use of models to understand periodic motion. The specific details of internal gating based on voxel fluctuations in US12171593 would determine the degree of anticipation.

25. US20090076369A1 - Method For Reducing Motion Artifacts In Highly Constrained Medical Images

• Full Citation: US20090076369A1
• Publication Date: 2009-03-19
• Priority Date: 2007-09-17
• Assignee: Mistretta Charles A
• Brief Description: This patent application describes methods for reducing motion artifacts in medical images.
• Potential Anticipated Claim(s): This is generally relevant to the problem US12171593 aims to solve. It could anticipate the general concept of "generating at least one image correcting for the periodic motion" in Claim 1, depending on the specific techniques described for reducing motion artifacts.

26. US20090299184A1 - Imaging or communications system utilizing multisample apodization and method

• Full Citation: US20090299184A1
• Publication Date: 2009-12-03
• Priority Date: 2008-02-16
• Assignee: Walker William F
• Brief Description: This patent application relates to imaging systems utilizing multisample apodization. This might involve signal processing techniques that could indirectly affect motion artifact reduction but is not directly about retrospective internal gating.
• Potential Anticipated Claim(s): This patent is likely less directly anticipatory of the core claims of US12171593 compared to those explicitly dealing with motion correction or gating, as its focus appears to be on image acquisition and processing techniques unrelated to the generation of a motion function from cyclical signals.

Most Relevant Prior Art

The most relevant prior art for US patent 12171593 are its direct parent applications and granted patents from the same patent family, as they disclose the same invention with earlier priority dates. These include:

• US9814431B2 (Publication Date: 2017-11-14, Priority Date: 2007-05-04, Assignee: Memorial Sloan Kettering Cancer Center)
• US10117625B2 (Publication Date: 2018-11-06, Priority Date: 2007-05-04, Assignee: Memorial Sloan Kettering Cancer Center)
• US10448903B2 (Publication Date: 2019-10-22, Priority Date: 2007-05-04, Assignee: Memorial Sloan Kettering Cancer Center)
• US10863950B2 (Publication Date: 2020-12-15, Priority Date: 2007-05-04, Assignee: Memorial Sloan Kettering Cancer Center)
• US11369322B2 (Publication Date: 2022-06-28, Priority Date: 2007-05-04, Assignee: Memorial Sloan Kettering Cancer Center)

These patents are continuations of earlier applications that claim priority back to the same provisional application, meaning they cover the same or very similar subject matter with an earlier effective filing date. Therefore, they would directly anticipate all claims of US12171593 under 35 U.S.C. § 102.

Beyond the direct family members, other highly relevant prior art that broadly or specifically addresses retrospective internal gating, data-driven motion correction, or respiratory motion extraction in medical imaging include:

• US7359535B2 - "Systems and methods for retrospective internal gating"
• US20050123183A1 - "Data driven motion correction for nuclear imaging"
• US7756307B2 - "Method of, and software for, conducting motion correction for a tomographic scanner"
• US7574249B2 - "Device-less gating of physiological movement for improved image detection"
• US20080253636A1 / US8229187B2 - "Respiratory motion extraction from tomographic projection and image data"

Obviousness Analysis of US12171593 under 35 U.S.C. § 103

This analysis will identify combinations of prior art references that would render the claims of US12171593 obvious to a person having ordinary skill in the art (PHOSITA) as of the priority date of May 4, 2007.

The central theme of US12171593 is retrospective internal gating for medical imaging, specifically deriving respiratory motion information from individual voxel signal fluctuations to create a time-varying object motion function and subsequently correct images for motion without external hardware.

A PHOSITA in this field would have a strong understanding of medical imaging modalities (PET, CT, MRI), image reconstruction techniques, motion artifacts in imaging, and various methods for motion correction, including gating techniques. They would also be familiar with both hardware-based and software-based (data-driven) approaches to motion detection.

Independent Claims (Claim 1, 19, 20):

The independent claims cover:

1. Acquiring successive digital images with temporally cyclical signals corresponding to periodic motion.
2. Extracting information for a plurality of arrays (voxels) in these images.
3. Generating a time-varying object motion function based on this extracted information.
4. Determining phase information for the periodic motion from the motion function.
5. Generating a motion-corrected image using the acquired data and phase information.

Combinations of Prior Art References and Motivation for Combination:

Combination 1: US7359535B2 in view of US20050123183A1 and US6144874A (or US9814431B2 and US6144874A)

• US7359535B2 (Systems and methods for retrospective internal gating): This patent, which is a predecessor to US12171593 and shares the same assignee and essentially the same title and abstract, explicitly describes a method for retrospective internal gating using image-based data. It details acquiring images, identifying temporally cyclical signals, and combining them to create a time-varying object motion function that correlates acquisition times with phases of periodic motion. The abstract of US12171593 states it is a method for "deriving respiratory gated PET image reconstruction from raw PET data" and uses "respiratory motion information derived from individual voxel signal fluctuations, is used in combination to create usable respiratory phase information." This core concept of retrospectively deriving motion from image data itself is clearly taught.

• US20050123183A1 (Data driven motion correction for nuclear imaging): This application further reinforces the concept of "data-driven motion correction" in nuclear imaging. It explicitly discusses deriving motion information directly from the image data, which aligns with the "internal" aspect of US12171593.

• US6144874A (Respiratory gating method for MR imaging): This patent discloses respiratory gating for MR imaging. While specific to MR, it teaches the fundamental concept of using respiratory signals to gate imaging and improve image quality by reducing motion artifacts.

• Motivation for Combination: A PHOSITA would be highly motivated to combine these references to achieve improved image quality in PET imaging without external hardware. US7359535B2 (or US9814431B2) already lays the groundwork for retrospective internal gating. US20050123183A1 provides the explicit concept of "data-driven" motion correction, further solidifying the idea of extracting motion directly from the image data. US6144874A, and the general knowledge of respiratory gating in MRI (which had been explored extensively), would motivate the PHOSITA to apply retrospective gating techniques, particularly data-driven approaches, to PET imaging to address similar motion artifact problems (e.g., blurring of the torso due to respiratory motion in PET imaging). The advantages of software-derived signals over hardware-based methods, such as machine independence and no additional cost other than processing time, would further motivate this combination.

Reasoning for Obviousness:

Claim 1 of US12171593 describes acquiring images with cyclical signals, extracting voxel information, generating a time-varying object motion function, determining phase information, and generating a motion-corrected image.

• Acquiring image data with temporally cyclical signals corresponding to periodic motion: This is a fundamental step in any gated imaging system. US7359535B2 explicitly mentions acquiring images at different times to obtain a chronologically ordered image set where temporal sampling is short relative to periodic motion. Numerous prior art references discuss acquiring image data while a subject is undergoing periodic motion (e.g., respiration, cardiac rhythm) and the need to address the resulting artifacts.
• Extracting information for a plurality of arrays (voxels): US7359535B2 describes visualizing "time-activity information specific for a sample individual voxel" and deriving this by organizing the values of an individual voxel in successive images into a discrete array. This directly teaches extracting information at the voxel level. The concept of using information from voxels or projection data to derive motion is also evident in other prior art, such as US20080253636A1 (Respiratory motion extraction from tomographic projection and image data) and US8229187B2 (Respiratory motion extraction from tomographic projection and image data) which describe extracting respiratory motion from tomographic projection and image data.
• Generating a time-varying object motion function based on the extracted information: US7359535B2 explicitly states that "Information is combined from many voxels' time-activity values to create a time varying object motion function." It further explains that this is achieved by evaluating voxels and their respective time-activity information individually and that the "time varying object motion function is a summation of filtered individual voxel time-activity curves." This precisely teaches this step.
• Determining phase information for the periodic motion: US7359535B2 states, "Final phase information for the motion of the imaged object can be extracted from the timing of the peaks and dips in the time varying object motion function." This directly describes determining phase information from the generated motion function. The general concept of identifying phases of motion from a detected signal for gating purposes is well-known in the prior art (e.g., identifying inspiration and expiration phases for respiratory gating).
• Generating at least one image correcting for the periodic motion: Once phase information is determined, generating a corrected image is the ultimate goal of gating techniques. US7359535B2 notes that phase information is used "in the mapping of image data to phase of motion," and that "mapped image data is reordered and categorized in such a way that images within a category all appear to be taken at the same phase of motion." This describes the outcome of generating motion-corrected images. Many prior art documents discuss generating motion-corrected or gated images.

Therefore, the combination of US7359535B2 with the general knowledge of data-driven motion correction and respiratory gating techniques would lead a PHOSITA to the claimed invention. The features of claims 1, 19, and 20 are explicitly taught or made obvious by US7359535B2, which itself is a direct antecedent to the current patent.

Combination 2: US20080253636A1 (or US8229187B2) in view of US7574249B2 and US6539074B1

• US20080253636A1 (Respiratory motion extraction from tomographic projection and image data): This reference teaches extracting respiratory motion from tomographic projection and image data. It focuses on deriving motion from the acquired data itself.

• US7574249B2 (Device-less gating of physiological movement for improved image detection): This patent specifically addresses "device-less gating," emphasizing the benefit of not using external hardware for physiological motion detection. This aligns directly with the "internal" aspect of US12171593.

• US6539074B1 (Reconstruction of multislice tomographic images from four-dimensional data): This patent discusses the reconstruction of tomographic images from four-dimensional data, where the fourth dimension often relates to temporal changes or motion.

• Motivation for Combination: A PHOSITA, aiming to improve image quality by correcting for respiratory motion without external devices, would combine these references. US20080253636A1 (or US8229187B2) provides the mechanism for extracting motion signals directly from the imaging data. US7574249B2 reinforces the desire and advantage of "device-less" or "internal" gating. US6539074B1 provides the broader context of reconstructing images from time-varying (4D) data, which is where the extracted motion information would be applied to generate corrected images. The goal of lessening image degradation from respiratory motion by separating the breathing cycle into different phases and generating images from data corresponding to each phase is well-established in the art.

Reasoning for Obviousness:

• The steps of acquiring images and extracting voxel-level information are taught by US20080253636A1's focus on extracting respiratory motion from image and projection data.
• The concept of a "time varying object motion function" derived from this internal data is implicitly present in the idea of "respiratory motion extraction" from data without external devices.
• The "device-less" aspect of US7574249B2 directly motivates the internal, software-based approach of US12171593.
• The generation of motion-corrected images based on phase information derived from the motion function would be an obvious application of the extracted motion data, especially in the context of 4D image reconstruction as taught by US6539074B1.

Combination 3: US20050123183A1 (Data driven motion correction for nuclear imaging) in view of US6298260B1 (Respiration responsive gating means and apparatus and methods using the same) and US1910130105 (Extraction of cardiac and respiratory motion cycles by use of projection data and its applications to NMR imaging)

• US20050123183A1 (Data driven motion correction for nuclear imaging): This patent application directly describes data-driven motion correction for nuclear imaging. It focuses on extracting motion information directly from the acquired nuclear imaging data, such as PET data.

• US6298260B1 (Respiration responsive gating means and apparatus and methods using the same): This patent describes a method and system for gating therapeutic or diagnostic energy to a tissue volume during a selected portion of the patient's respiratory cycle to diminish inaccuracies due to respiration. While it discusses external monitoring (e.g., gas flow, pressure, lung volume), the core idea of using respiratory cycle information for gating and improving spatial accuracy is clearly taught.

• US1910130105 (Extraction of cardiac and respiratory motion cycles by use of projection data and its applications to NMR imaging): This reference explicitly teaches "extracting cardiac and respiratory motion cycles by use of projection data." This is a direct teaching of deriving physiological motion signals from the acquired raw imaging data.

• Motivation for Combination: A PHOSITA would be motivated to combine these to implement an entirely internal, data-driven respiratory gating solution for nuclear imaging. US20050123183A1 provides the general framework of data-driven motion correction in nuclear imaging. US6298260B1 clearly establishes the need and benefit of respiratory gating for diagnostic accuracy. US1910130105 provides the specific technical approach of extracting respiratory motion from projection data, which is analogous to extracting information from voxels in a reconstructed image for a data-driven method, especially since image reconstruction from projection data is a standard practice in tomographic imaging. The desire for a fully automated method that does not require external hardware and provides temporal alignment of the respiratory trace and image data would drive this combination.

Reasoning for Obviousness:

• The acquisition of image data with cyclical signals is inherent in any system that seeks to extract respiratory motion.
• Extracting information for voxels (arrays) is directly suggested by US1910130105's teaching of extracting motion from "projection data," as voxels represent spatial elements within an image derived from such data.
• Generating a time-varying object motion function and determining phase information from it would be an obvious way to utilize the extracted motion cycles, as demonstrated by the purpose of gating described in US6298260B1.
• Generating a motion-corrected image based on this phase information is the explicit goal of respiratory gating, as taught by US6298260B1 and generally understood in the art.

In conclusion, the core method, computer-readable medium, and system claims of US12171593, which describe retrospective internal gating by deriving a time-varying object motion function from voxel signal fluctuations, would have been obvious to a PHOSITA in light of the cited prior art. The motivation to combine these references stems from the well-recognized problem of motion artifacts in medical imaging and the desire to develop accurate, automated, and hardware-independent solutions for motion correction, particularly for respiratory motion.