In re Abbott Diabetes – Prosecution Lessons

by Ryan Alley on October 2, 2012

in +, CAFC PTAB appeals

Case Nos. 2011-1516 (Lourie, Prost, Wallach)

Broadest reasonable interpretations of claim terms during prosecution might not always be so, well, broad. In re Abbott Diabetes Care builds on cases like Suitco Surface in illustrating situations where claim context and specification treatment can mandate a claim interpretation short of the prior art. What makes Abbott especially interesting and useful is that the USPTO’s claim construction was not altogether beyond what prosecutors are accustomed to seeing their claims stretched to, and Abbott’s arguments closely resembled those are routinely dismissed as “importing limitations from the specification.” So there may be lessons and citable material here against an Examiner’s particularly taut claim interpretation.

Abbott DiabetesUS Patents 6,175,752 and 6,565,509, dealing with blood glucose sensors, were ensnared in some ex parte reexamination requests that stayed their litigation. During the reexamination, the Examiner rejected all claims at issue as met by several patent and non-patent references centering around EPO application 0 098 592 to Shichiri and US Patent 5,390,671 to Lord. In applying this prior art, the examiner relied on broad constructions of the following claims:

1. A sensor control unit comprising:
a housing adapted for placement on skin and adapted to receive a portion of an electrochemical sensor extending out of the skin having a plurality of contact pads;
a plurality of conductive contacts disposed on the housing and configured for coupling to the plurality of contact pads on the electrochemical sensor; and
an rf transmitter disposed in the housing and coupled to the plurality of conductive contacts for transmitting data obtained using the electrochemical sensor.

Other claims under reexamination added that “the portion of the sensor above the skin is maintained in a substantially fixed position relative to the position of the sensor control unit when the sensor control unit is placed on the skin and receives the proximal end of the sensor transcutaneously positioned.”

The Examiner rejected all these claims by interpreting the recited “electrochemical sensor” as inclusive of wires or cables that connected the sensor to various other components under BRI. The Board affirmed these rejection and denied a rehearing for the same in both patents under reexam. The Board further interpreted the “substantially fixed” term to include only somewhat restrained relative movement between the sensor and control unit, such as a freely-movable control unit on a patient’s wrist tethered to a sensor elsewhere on the body, in the denial for rehearing.

On appeal, Abbott marshaled three arguments against the USPTO’s construction of “electrochemical sensor”:

1) Claim language of “contact pads” that are “coupled to” or “receive[d]” by “conductive contacts” was narrower than language that would require unlimited electrical connection types. This suggested intermediate external wiring was not involved.

2) The specifications of both the ’752 and ’509 patents disparaged external cables and wires between the sensor and external devices, stating that the “size of the sensor guides and presence of cables and wires hinders the convenient use of [the prior art] for everyday applications.”

3) Every disclosed embodiment in the ‘752 and ‘509 specification and figures lacked free external wiring or any discussion of the same.

The Federal Circuit held that these three pieces of evidence constrained the broadest, reasonable interpretation of “electrochemical sensor” to a sensor that used something other than cables or wires to connect to the sensor unit. The court agreed with the first point – the claim language fairly suggested a direct pad/contact connection without wires. But this suggestion alone was likely insufficient to narrow the claim; the panel found the combination of the suggestion and consistency of the specification to be dispositive. In doing so, the court refuted several common bases advanced by the USPTO for a broader construction. The Office argued disparagement of prior art sensors using only wires or cables nonetheless demonstrated that wires and cables fell within the understanding of a sensor. The Office noted that the specification further lacked any explicit redefinition or In re Bigio-required disclaimer of “electrochemical sensor”; instead, the specification discussed a lack of cables or wires only in connection with the control unit, and even there the treatment was ambiguous. But this was not the correct treatment of the specification:

“Although the PTO emphasizes that it was required to give all claims their broadest reasonable construction, . . . this court has instructed that any such construction be consistent with the specification, and that claim language should be read in light of the specification as it would be interpreted by one of ordinary skill in the art.” In re Suitco Surface, Inc., 603 F.3d 1255, 1260 (Fed. Cir. 2011) (internal citation and quotation marks omitted). Indeed, “the specification ‘is always highly relevant to the claim construction analysis. Usually it is dispositive; it is the single best guide to the meaning of a disputed term.’” Phillips v. AWH Corp., 415 F.3d 1303, 1315 (Fed. Cir. 2005) (en banc) (quoting Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)). Here, the specification contains only disparaging remarks with respect to the external cables and wires of the prior-art sensors: “[t]he size of the sensor guides and presence of cables and wires hinders the convenient use of these devices for everyday applications.” ’752 patent col.1 ll.57-59; ’509 patent col.1 ll.61-63. In fact, the primary purpose of the invention was to provide “a small, compact device that can operate the sensor and provide signals to an analyzer without substantially restricting the movements and activities of the patient.” ’752 patent col.1 ll.60-63; ’509 patent col.1 ll.64-67.

Even more to the point, every embodiment disclosed in the specification shows an electrochemical sensor without external cables or wires. Indeed, the only mention of a sensor with external cables or wires in Abbott’s patents is a single statement addressing the primary deficiency of the prior art. It is true that the specification does not contain an explicit statement disclaiming electrochemical sensors with external cables or wires. But this is not an instance where the specification would necessarily have to disavow an embodiment that would otherwise be covered by the plain language of the claims—rather, claim terms like “coupl[ed]” and “receiv[ed]” are entirely consistent with and even support the specification’s exclusive depiction of an electrochemical sensor without external cables or wires. We have held that “[e]ven when guidance is not provided in explicit definitional format, the specification may define claim terms by implication such that the meaning may be found in or ascertained by a reading of the patent documents.” Irdeto Access, Inc. v. Echostar Satellite Corp., 383 F.3d 1295, 1300 (Fed. Cir. 2004) (internal quotation marks omitted). Here, Abbott’s patents “repeatedly, consistently, and exclusively” depict an electrochemical sensor without external cables or wires while simultaneously disparaging sensors with external cables or wires. Id. at 1303.

To build on the redefinition by implication phenomenon supported by Irdeto Access, the panel revisited some very prominent BRI caselaw. The exegesis strongly suggested that consistent, unfavorable treatment of a particular interpretation of a claim terms in the specification would take that interpretation outside of BRI:

While Abbott’s patents define the electrochemical sensor’s connectivity by implication, the PTO argues that our case law still requires an explicit disclaimer of external cables or wires. But the PTO’s reliance on cases like Amer[i]can Academy of Science and Retractable Technologies is misplaced. Although the patentee in Amer[i]can Academy of Science argued that it had disparaged and therefore disclaimed the use of “multi-user computers such as mainframes” in the background of the invention section of its patent, that same background section and the “specification as whole” actually supported configurations that included multi-user computers. 367 F.3d at 1367. And in Retractable Technologies, the patentee’s supposed disclaimer of “cutting” in the background of the invention was undermined by an embodiment in the specification that indicated that some forms of cutting fell within the scope of the claimed invention. 653 F.3d at 1306. In the case before us, however, nothing suggests or even hints that the claimed electrochemical sensor can include external cables or wires. Instead, Abbott’s patents consistently show the opposite.

Under this reasoning, the discussion of usually no wires or cables only in connection with the control unit was insufficient to raise American Academy of Science- or Retractable Technologies-like inconsistencies in the non-wired treatment of sensors. Because the specification consistently disclosed example embodiment sensors as limited to non-wire-dependent structures and disparaged prior art relying on wires or cables, this confirmed the claim’s suggestion of so limiting the recited sensor. The rejections based on an interpretation of “electrochemical sensor” as including only free, external wires and cables for communication was reversed and remanded for proceedings consistent with an interpretation of “electrochemical sensor” that used non-wired contacts.

The court also reversed and remanded the “substantially fixed” interpretation with very brief analysis. Specifically, the Board’s (re-)interpretation of the term in the denial was simply inconsistent with the specification. The court stated that a control unit freely movable on the arm away from a body-bound sensor was,

not only significantly greater than the movement allowable under the Board’s original construction of “substantially fixed,” it is also greater than the movement described in the specification. Indeed, the embodiments disclosed in the ’509 patent all show the above-skin portion of the electrochemical sensor maintained in a fixed position. Specifically, the specification teaches a “support structure 82” that “hold[s], support[s], and/or guide[s] the sensor 42 into the correct position.” ’509 patent col.34 ll.54-55.

Lessons: Abbott looks like a great case to cite against an Examiner’s broad claim interpretation when 1) the specification explicitly treats the Examiner’s interpretation unfavorably, and 2) disclosed example embodiments and claim language in no way counter this by favorably treating, requiring, or “suggesting” the Examiner’s interpretation. Under the first prong, Abbott makes it clear that absolute disclaimer, redefinition, or disavowal is not required. Although the facts in Abbott involved mere criticism of the prior art, I would think that clear criticism of anything in the specification, regardless if it is prior art, would work. For the second requirement, you probably need claim language that suggests a more limited construction by using terms that are narrower than the broader interpretation, and that “narrower” needs to be in the “direction” of the limited construction (e.g. “pads . . . received by . . . contacts” is narrower than “electrically connected to” in a way that moves away from free-wire/cable-based connections).

Some best practices counsel for never making any negative comments about the prior art or elements not present in the invention; that is, everything is to be stated as an advantage of example embodiments. This practice is borne out of concerns about inequitable conduct in misleading the Office about the nature of the prior art, running afoul of MPEP 608.01(r), and providing the Examiner an “obviousness roadmap” by finding other prior art that also lacks the negative features. While I think this “all advantages” route in application drafting has merit if unsure about the prior art, it probably won’t invoke the limiting rule of Abbott, which seems to require a clear negative/problem statement. It’s a case-by-case situation, but where an invention does recognize and overcome an existing problem in known features that one would never want claim scope coverage over, I see little downside in including a general statement of problems newly recognized in existing features. Abbott adds to the worth of this approach in that it can help turn back a broad claim construction that recaptures the prior art features causing the problems.

I don’t draw any strong lessons from the court’s reversing the interpretation of “substantially fixed.” The opinion is a little conclusory in saying that the asserted prior art wrist attachment interpretation was inconsistent with the specification. I’m not sure if it was because the Board somewhat capriciously adopted that interpretation only in rehearing or because “substantially fixed” is a degree-type limitation that necessarily is more closely tied to the specification for its understanding. Maybe consider a cite to Abbott when faced with a really broad interpretation of a degree-type term that is described much more narrowly in the specification, and let me know how it goes.

Comment: I see this opinion as drawing the “broadest, reasonable interpretation” standard back from its current border, at least in the above-identified specific circumstances of Abbott. To me, the interpretation set down by the Federal Circuit feels closer to a litigation construction. That’s not a huge problem, sometimes the two standards are equivalent. I just observe that Abbott is very likely now prosecution history estopped from ever trying to assert their claims over devices that use sensors with only wired or cabled connections to an outside device. Had this issue in reexamination and case never occurred, however, would a proper claim construction at litigation have also not included the wire/cable interpretation? The answer must be “yes” given BRI never being narrower than litigation constructions, right? Yet I wonder if cases looking at specification implicit redefinition and disclaimer in claim construction would always require a non-wired construction.

Lastly, the ‘752 patent is claimed to for priority by over 100 different child applications. Talk about a fertile application.

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