Did the CAFC Extrapolate From the Teachings of the References to Reach the Conclusion of Obviousness?
Bill Schertler | August 12, 2013
In re Adler
July 18, 2013
Panel: Prost, Reyna and Wallach. Opinion by Wallach
The Examiner rejected all of the pending claims under 35 U.S.C. §103 as obvious over several prior art references, including International Patent Publication WO 00/22975 (“Meron”) in view of Masaru Hirata et al., Study of New Prognostic Factors of Esophageal Variceal Rupture By Use of Image Processing With a Video Endoscope, 116 Surgery 8–16 (1994) (“Hirata”).
The Board of Patent Appeals and Interferences (“the Board”) affirmed the Examiner’s rejection of all pending claims of U.S. Patent Application No. 10/097,096 (the ‘096 application) under 35 U.S.C. §103 as being obvious over a combination of prior art references. Adler appealed the Board’s decision to the Court of Appeals for the Federal Circuit (CAFC). The CAFC affirms holding that the Board did not err in rejecting the pending claims as obvious and did not rely on new grounds for rejection.
The ‘096 application relates to a system and method for detecting pathologies of the gastrointestinal (GI) tract, such as bleeding, lesions, polyps, etc., by detecting blood within a body lumen. The system includes a swallowable capsule having an imager for obtaining images from within the body lumen. The images obtained by the imager are compared to two reference values, one for healthy tissue and one for blood. Based on the comparisons, an indication of the position in the GI tract of a change on the level of red color content, correlating with the presence of blood, is displayed thereby allowing for detection of colorimetric abnormalities such as bleeding or clots.
Representative claim 57 is set forth below.
57. A method for displaying in-vivo information, the method comprising:
receiving at a data processor data generated by a swallowable in-vivo device traversing a GI tract, the data comprising a set of in-vivo images of the GI tract;
the data processor comparing values of the received images to a reference value of blood and to a reference value of healthy tissue;
the data processor causing to be displayed the images as a color video; and
the data processor further, based on the comparison, causing to be displayed an indication of the position in the GI tract of a change in the level of red color content, the change correlating to the presence of blood.
‘096 disclosure: “A distance vector r(B,T) between test sample T and an ideal pathology sample B is calculated. Another distance vector r(R,T) between test sample T and a reference sample of healthy tissue R is calculated. The relationship of distance vector r(B,T) and distance vector r(R,T) is calculated. Each test sample T is classified based on the relationship between distance vector r(B,T) and distance vector R(R,T). Briefly, if distance vector r(B,T) is small relative to distance vector r(R,T), there is a positive indication of pathological disorder. In the preferred embodiment, the analysis is set up to include a higher possibility of false positives than false negatives, so as to minimize the likelihood of missing a positive diagnosis.”
During prosecution and on appeal before the Board and the CAFC, Adler argued that the combined teachings of Meron and Hirata do not disclose the method steps related to the detection of the presence of blood, i.e., “the data processor comparing values of the received images to a reference value of blood and to a reference value of healthy tissue” and “the data processor further, based on the comparison, causing to be displayed an indication of the position in the GI tract of a change in the level of red color content, the change correlating to the presence of blood.”
The Meron reference was relied upon for its disclosure of a capsule camera that moves through the GI tract to generate a map of the GI tract. The Hirata reference was relied upon to teach the methods steps related to the detection of the presence of blood.
Based on the Meron reference, Adler did not dispute that the prior art discloses a swallowable in-vivo image-sensing device capable of transmitting images and location information to an external display.
However, Adler did dispute the Board’s interpretation of the Hirata reference, particularly, Adler argued that Board failed to appreciate that Adler’s claims refer to two comparisons to determine whether a change in the level of red color content correlates to the presence of blood.
The primary issue on appeal was whether the Board properly found that it would have been obvious in light of the prior art to compare reference values for healthy tissue and blood to determine whether images of the gastrointestinal tract showed “a change in the level of red color content” where that “change correlat[es] to the presence of blood,” as articulated in the claims at issue.
The Hirata reference discloses a study of factors of esophageal variceal rupture by use of a video endoscope. The Board relied on Hirata’s disclosure that color tone was analyzed by comparing the red color tone of a defined varices region with the red color tone of a defined normal esophageal region. The defined regions are selected by the doctor. Hirata discloses that the two color tones are used to form a ratio value termed “Rr” (ratio of red signal).
The Board concluded that ratio Rr of Hirata discloses comparing the color tone of the known variceal region with the color tone of the known healthy esophageal region. This ratio was used to predict variceal bleeding. Hirata disclosed that “If Rr is less than 1, the possibility of variceal rupture seemed high.”
The Board found that Hirata made comparisons in his follow-up study of the non-bleeders, when he compared the color tone of non-bleeders with the color tone of bleeders – Hirata was taking a (new) test sample from the non-bleeders and comparing it to the “Rr” of the bleeders, where “Rr” represents a combined reference value of healthy tissue and a reference value of blood.
Adler responded to the Board’s analysis, arguing “the claim requires three values to be used in the two comparisons” and that “Hirata discloses one comparison of two values”.
In affirming the Board’s decision, the CAFC stated that Adler overlooked the Board’s rationale, “which explains that one of ordinary skill in the art would equate red color with present bleeding and would be motivated to build on Meron’s teachings concerning received images from a swallowable device that could be compared to the reference values disclosed in Hirata. This is a predictable variation of the combination of Hirata and Meron. See KSR, 550 U.S. at 417 (‘If a person of ordinary skill can implement a predictable variation, §103 likely bars its patentability.’).”
Since the decision in KSR v. Teleflex, Examiners, the Board, and the CAFC have in certain instances found obviousness by extrapolating from the teachings of the references. This extrapolation has been supported, for example, by rationales that such extrapolation is “common sense” or “a predictable variation”.
Because there is necessarily subjectivity in ascertaining what is a common sense or predictable extrapolation or extension of the reference teachings, the practitioner is left in a difficult position. If the allowance of the claims turns on ascertaining what is considered a reasonable extrapolation from the reference teachings, at least make sure that additional claims that distinguish over any such extrapolation are present.