BPAI Finds Method for Interpreting an MRI Image Statutory Even Though Not Tied to a Machine Implementation

In Ex Parte Jack, (Appeal 2009-015192), handed down February 9, 2011, the Board of Patent Appeals and Interferences (BPAI) found a method for classifying tissue in a magnetic resonance image statutory subject matter under Section 101.  The BPAI reversed the Examiner’s rejection of the claim under Section 101, as well as a rejection of the claims under Section 103.  Quoting from the opinion:

 “Similar to the Research Corporation claims, the instant claims are directed to a method for interpreting a magnetic resonance image by measuring, pixel-by-pixel, the image intensity and statistically analyzing a frequency-versus-intensity histogram. The Examiner has not alleged that the claims are directed to a law of nature or physical phenomenon, and we conclude that the claimed process is not so manifestly abstract as to override the broad statutory categories of eligible subject matter recited in § 101. SeeResearch Corporation, 627 F.3d at 868. The rejection of the claims as directed to nonstatutory subject matter is reversed.”

 The Specification of the Ex Parte Jack application discloses a method for “automatically measuring the volume of tissue in a region of interest by acquiring a magnetic resonance image, constructing a pixel intensity histogram of the image, and segmenting the histogram using a statistical regression analysis” (Spec. 5, qr 18). The “histogram is produced by counting the number of image pixels at each possible image intensity level and plotting the result as a frequency versus intensity graph” (id. at 5, qr 20).

Claims 1 and 4 are representative of the claims found statutory and read as follows:

1. A method of classifying tissue in a magnetic resonance image, the method comprising:

(a) acquiring a magnetic resonance image of a region of interest;

(b) constructing a pixel intensity histogram of the magnetic resonance image; and

(c) applying a statistical regression analysis to the histogram to determine a pixel intensity threshold value for segmenting the histogram into at least two regions, wherein at least one of the regions is representative of a tissue of interest.

4. The method as defined in claim 1, wherein the statistical regression analysis of step (c) comprises:

(i) identifying a consistently identifiable statistical characteristic of the histogram;

(ii) determining a statistical parameter of the consistently identifiable statistical characteristic; and

(iii) applying the statistical parameter as an independent variable in a regression analysis to determine a threshold value to classify pixels based on pixel signal intensity.

            What is interesting about this case and the RCT decision is that the method claims in question are not in any way tied to a computer implementation, although in both cases the claims involve imaging applications so are inherently limited to the interpretation or display of images that are certainly not “manifestly abstract.”  If this line of reasoning holds up, patentees and practicioners may finally be relieved from having to follow formalistic claiming conventions invoking computer implementation of methods in order to avoid abstract idea objections under Section 101.  These formalisms do little if anything to limit the substantive scope of claims but can complicate claim drafting so as to introduce unnecessary limitations that unfairly limit the patentee’s claim scope purely to meet formalistic and anachronistic Section 101 requirements.

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