Obviousness

Obviousness Analysis of US Patent 10863950 under 35 U.S.C. § 103

This analysis identifies combinations of prior art references that would render the claims of US patent 10863950 obvious to a person having ordinary skill in the art (POSITA) as of the patent's effective priority date, which is June 4, 2007 (derived from U.S. Provisional Patent Application 60/916,200, filed Jun. 4, 2007).

The present invention, US10863950, describes methods and systems for retrospective internal gating, particularly for medical imaging, to correct for motion artifacts like respiratory motion. The patent emphasizes the use of image-based, software-derived signals to create a time-varying object motion function without external hardware.

The independent claims (Claims 1, 21, and 22) essentially describe a method, computer-readable medium, and system, respectively, for:

1. Acquiring image data of a moving object over time.
2. Extracting information from arrays (e.g., voxels) in the image data.
3. Generating a time-varying object motion function from this extracted information.
4. Determining phase information of the object's motion using the motion function.
5. Generating a motion-corrected image using the phase information and acquired data.

Combination of Prior Art References

The combination of US20050123183A1 (Schleyer) and US7359535B2 (GE Medical Systems) would render the independent claims of US10863950 obvious. Both references address the problem of motion artifacts in medical imaging and propose solutions involving internal, data-driven approaches.

• US20050123183A1 (Schleyer): "Data driven motion correction for nuclear imaging" (Priority Date: 2003-09-02)

  • Schleyer teaches a method for motion correction in nuclear imaging by "acquiring a sequence of image data frames over a time interval during which a physiological motion is present". This directly addresses Element 1 (acquiring image data).
  • It further teaches "identifying a plurality of regions of interest (ROI) in said image data frames; extracting signal data from said regions of interest over said time interval, thereby generating a plurality of ROI time-activity curves". This covers Element 2 (extracting information for a plurality of arrays, where ROIs are collections of array elements like voxels).
  • Schleyer discloses "generating a motion function based upon said extracted signal data, said motion function describing a phase of said physiological motion as a function of time". This explicitly addresses Element 3 (generating a time-varying object motion function) and Element 4 (determining phase information).
  • Finally, Schleyer teaches "reconstructing a motion corrected image from said segmented image data frames". This directly corresponds to Element 5 (generating at least one image correcting for the motion).

• US7359535B2 (GE Medical Systems): "Systems and methods for retrospective internal gating" (Priority Date: 2003-06-20)

  • GE Medical Systems explicitly teaches "retrospective internal gating" as a solution to image degradation due to patient motion.
  • The patent describes "receiving image data generated by an imaging system for a moving object", addressing Element 1.
  • It discloses "identifying temporally cyclical signals, which are combined to create a time varying object motion function which correlates times t 1 . . . tn and the phases of the periodic motion". This addresses Element 2 (by identifying signals from images/voxels), Element 3 (generating a time-varying object motion function), and Element 4 (determining phase information). The detailed description of US10863950 (which shares lineage with US7359535B2) further clarifies that "time-activity information specific for a sample individual voxel" is derived and used.
  • The core purpose of "respiratory gating" as described is "to lessen the image degradation from respiratory motion by separating the breathing cycle into different phases and generating images from data corresponding to each of these phases". This inherently leads to generating motion-corrected images, covering Element 5.

Motivation to Combine

A POSITA in the field of medical imaging, faced with the challenge of motion artifacts and seeking to develop a device-less, software-based solution, would have been highly motivated to combine the teachings of Schleyer and GE Medical Systems.

Both references tackle the same problem using similar philosophical approaches: leveraging internally derived image data for motion correction rather than external hardware. Schleyer provides a clear framework for deriving a motion function from signal data extracted from regions of interest. GE Medical Systems explicitly introduces the concept and utility of "retrospective internal gating" and extracting phase information from a time-varying object motion function derived from image-based cyclical signals.

A POSITA would recognize that:

• The "regions of interest" in Schleyer are analogous to the "plurality of arrays" or voxels mentioned in US10863950 and implied by GE Medical Systems.
• The "motion function" described by Schleyer directly aligns with the "time varying object motion function" of GE Medical Systems and US10863950.
• The objective of "motion corrected images" (Schleyer) is achieved through "respiratory gating" and phase determination (GE Medical Systems).

Therefore, combining Schleyer's detailed methodology for data extraction and motion function generation from image data with GE Medical Systems' explicit focus on retrospective internal gating and phase information extraction would result in the method, computer-readable medium, and system of independent claims 1, 21, and 22, respectively. The combination would be driven by the clear benefits of a fully automated, image-based motion correction technique that avoids the complexities and costs associated with external gating hardware.

Obviousness of Dependent Claims

Many of the dependent claims introduce features that would have been obvious refinements or design choices to a POSITA combining Schleyer and GE Medical Systems:

• Claim 2 (Information as signal of array element): Schleyer's "ROI time-activity curves" and GE Medical Systems' use of "individual voxel signal fluctuations" (Abstract of US10863950, which details the invention for which GE Medical Systems is a parent) directly teach this.
• Claims 3, 4, 6, 15 (Weighting factors): Assigning weighting factors to arrays based on "mean array activity", "proximity to greater spatial signal gradients", or "magnitude of signal variation" would be an obvious design choice for a POSITA. Schleyer mentions "voxel weighting" in its abstract. In image processing, it is well-known to prioritize data points that exhibit significant change or high signal intensity when tracking motion, as these areas often provide more reliable motion indicators.
• Claim 7 (Zero weighting for unimportant arrays): This is a logical extension of using weighting factors to optimize processing by excluding irrelevant data, an obvious step for a POSITA to improve efficiency.
• Claims 8, 9, 10 (Frequency filtering): Filtering information in frequency space to encompass expected periodicity of motion is a standard signal processing technique to reduce noise and isolate relevant physiological signals (e.g., respiratory or cardiac cycles). US6144874A (GE Company) discusses "filtering the navigator data to determine a respiratory phase of the subject". US6539074B1 (GE Company) mentions "gating and filtering techniques" in the context of 4D image reconstruction from physiological cycles. Adjusting frequency windows based on patient or data specifics is a routine optimization.
• Claim 14 (Three scenarios for combining array information): The iterative combination of individual array information with an evolving motion function, considering addition, subtraction, or no change to account for phase mismatch and selecting the scenario with "most significant improvement" (e.g., highest standard deviation), would be an obvious approach for a POSITA. Signal processing commonly deals with combining signals that may be in or out of phase, and using metrics to identify the strongest signal or most significant motion would be a logical method for refining a motion function.

In conclusion, the independent claims, and many of the dependent claims, of US10863950 describe a system and method that would have been obvious to a POSITA when considering the combined teachings of prior art references such as US20050123183A1 (Schleyer) and US7359535B2 (GE Medical Systems), motivated by the desire to implement effective, software-based, internal motion correction in medical imaging.