Fed Circ contests PTAB over single or plural meaning in microfluidic device patent
Judges partially overturn decision that ABS had failed to prove claims in Cytonome patent were invalid | PTAB and appeals court differ in interpretation of whether claims language had single or plural meaning.
The US Court of Appeals for the Federal Circuit has determined that at least two claims of a patent belonging to biotech firm Cytonome are invalid, partly overturning a Patent Trial and Appeal Board (PTAB) decision and handing a win to ABS Global, a bovine artificial insemination company.
On Thursday, October 19, Circuit Judges Jimmie Reyna, Richard Taranto and Leonard Stark partly reversed and partly vacated the Board’s conclusion that ABS had failed to prove Cytonome’s patent was invalid, following a petition for inter partes review (IPR).
Cytonome’s patent, US number 10,583,439, relates to a device used for processing particles of interest in a sample fluid.
ABS petitioned for IPR of five claims of the patent in 2020, arguing anticipation or obviousness based on three references, which the Board rejected in April 2022.
The challenged claims were claim 1, which relates to a microfluidic device configured to focus sample fluid; and claims 2, 6, 8 and 9, which depend on claim 1.
ABS appealed the Board’s decision, arguing it had erred in its claim construction of a limitation common to all the challenged claims.
Singular or plural
Ultimately, the PTAB and the federal circuit judges differed in their interpretation of whether the language in claim 1 of the patent had a singular-only meaning or allowed for a plurality.
Judges disagreed with the Board’s determination that “the sample stream” cited in claim 1 was limited to a singular-only sample stream, and concluded that in fact it had a “plural-allowing meaning”.
Their reasoning includes a definition in the patent’s specification that: “the term ‘a’ or ‘an’ entity refers to one or more of that entity. As such, the terms ‘a’ or ‘an’, ‘one or more’ and ‘at least one’ can be used interchangeably herein.”
“The sample stream” referred to the earlier phrase “a sample stream”, the judges said, which meant that the stream could be referring to more than one.
Further determination needed
Regarding the other contested claims, the judges found that one of the references for anticipation cited by ABS disclosed an additional limitation in claim 8 of the patent, and therefore reversed the Board’s decision on this claim.
However, judges agreed with Cytonome regarding claims 2, 6 and 9, and vacated the Board’s final written decision on these, remanding the matter for further proceedings.
The court awarded costs to ABS.
The case was ABS Global v Cytonome. Sidley Austin represented ABS and Akin Gump Strauss Hauer & Feld argued for Cytonome.
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