Opinion ID: 208638
Heading Depth: 3
Heading Rank: 2

Heading: The Ensnarement Defense

Text: Medtronic argues that the district court erred in holding that hypothetical claim 1 would not have been obvious over a combination of Puno and Anderson. The district court found that Puno teaches away from the proposed combination and that various secondary considerations support a conclusion of nonobviousness. Ensnarement Order, 526 F.Supp.2d at 172-76. We review de novo the district court's conclusion that a hypothetical claim does not ensnare the prior art. Wilson Sporting Goods, 904 F.2d at 683. We review a district court's resolution of underlying factual issues in the ensnarement context for clear error. Cf. Festo, 493 F.3d at 1376 (applying clear error standard to review of fact-finding underlying foreseeability criterion). A helpful first step in an ensnarement analysis is to construct a hypothetical claim that literally covers the accused device. Interactive Pictures, 274 F.3d at 1380. Here, both parties agree that the following hypothetical claim literally covers the Vertex® model: Device for stabilizing spinal column segments, comprising a pedicle screw (1) having a threaded shaft portion (3) and a spherically-shaped head (4) at the end of said threaded shaft portion, a receiver member (5) flexibly connected to said head (4), said receiver member being provided with two holes for receiving a rod 916) [sic:(16)], a receiver chamber (7) being provided within said receiver member (5), the receiver chamber (7) having at one end thereof a bore (8) for passing the threaded shaft portion (3) therethrough and an inner hollow conically -shaped portion (9) for receiving the head (4) of said screw (1), an opening (10) being provided opposite said bore (8) for inserting said screw (1), said device further comprising a compression member (18) for exerting a force onto said head (4) such that said head is pressed against the hollow conically -shaped portion (9). '678 patent, cl.1 (emphases added to denote substitution of conically for spherically). Next, the district court must assess the prior art introduced by the accused infringer and determine whether the patentee has carried its burden of persuading the court that the hypothetical claim is patentable over the prior art. Interactive Pictures, 274 F.3d at 1380. Ultimately, [i]f such a claim would be unpatentable under 35 U.S.C. §§ 102 or 103, then the patentee has overreached, and the accused device is noninfringing as a matter of law. Id. Medtronic produced two references, Puno and Anderson, that it believes renders the hypothetical claim obvious under § 103. Puno discloses a polyaxial pedicle screw assembly, illustrated in figure 7 of Puno, reproduced below left, which the parties agree contains all elements of the claim other than a compression member for pressing the screw head against the receiver member. Because Puno's design lacks a compression member, the screw head 30 is separated from the receiver member, depicted in figure 7 as anchor seat 23, and achieves what Puno calls a shock absorber effect, allowing for some motion between the anchor seat and the vertebrae. Puno col.3 ll.60-63. This shock absorber effect prevent[s] direct transfer of load from the rod to the bone-screw interface prior to achieving bony fusion, thereby decreasing the chance of failure of the screw or the bone-screw interface. Id. col.3 ll.64-67. Medtronic asserts that Puno's missing compression member is readily found in Anderson. Anderson discloses an external fracture immobilization splint for immobilizing long bones, such as arm or leg bones, with a swivel clamp that is capable of polyaxial movement until it is rigidly secured by a compression member. The compression member is depicted in figure 4 of Anderson, reproduced below right, as sleeve 15 having a spherically-curved seat 15'. Anderson pg.2 col.2 ll.30-37. When asked on cross-examination at the ensnarement hearing whether a person of ordinary skill would have recognized that the addition of Anderson's compression member to Puno's device would have achieved a rigidly-locked polyaxial pedicle screw covered by the hypothetical claim, DePuy's expert answered I think so. J.A. 5557. Medtronic argues that this admission alone is sufficient to render the hypothetical claim obvious. We disagree. Although predictability is a touchstone of obviousness, the predictable result discussed in KSR refers not only to the expectation that prior art elements are capable of being physically combined, but also that the combination would have worked for its intended purpose. KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 127 S.Ct. 1727, 1739-40, 167 L.Ed.2d 705 (2007). As the Supreme Court explained, The combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results. Id. at 1739 (emphasis added). The Supreme Court went on to state that when a patent `simply arranges old elements with each performing the same function it had been known to perform' and yields no more than one would expect from such an arrangement, the combination is obvious. Id. at 1740 (quoting Sakraida v. Ag Pro, Inc., 425 U.S. 273, 282, 96 S.Ct. 1532, 47 L.Ed.2d 784 (1976)) (emphasis added). The opposite conclusion would follow, however, if the prior art indicated that the invention would not have worked for its intended purpose or otherwise taught away from the invention. See United States v. Adams, 383 U.S. 39, 52, 86 S.Ct. 708, 15 L.Ed.2d 572 (1966) (upholding nonobviousness where references teaching away from the claimed combination would deter any investigation into such a combination); In re ICON Health & Fitness, Inc., 496 F.3d 1374, 1382 (Fed.Cir.2007) ([A] reference teaches away from a combination when using it in that combination would produce an inoperative result.). An inference of nonobviousness is especially strong where the prior art's teachings undermine the very reason being proffered as to why a person of ordinary skill would have combined the known elements. Here, Medtronic asserts that achieving a rigid pedicle screw was itself the reason to combine Puno and Anderson. In rebuttal, DePuy argues, and the district court found, that Puno teaches away from a rigid screw because Puno warns that rigidity increases the likelihood that the screw will fail within the human body, rendering the device inoperative for its intended purpose. Ensnarement Order, 526 F.Supp.2d at 172. The district court thus found that Puno's teachings undermine the very reason Medtronic proffers as to why it would have been obvious to combine Puno and Anderson, viz., the creation of a rigid screw. A reference may be said to teach away when a person of ordinary skill, upon reading the reference, would be discouraged from following the path set out in the reference, or would be led in a direction divergent from the path that was taken by the applicant. Ricoh Co., Ltd. v. Quanta Computer Inc., 550 F.3d 1325, 1332 (Fed.Cir.2008) (quoting In re Kahn, 441 F.3d 977, 990 (Fed.Cir.2006)). A reference does not teach away, however, if it merely expresses a general preference for an alternative invention but does not criticize, discredit, or otherwise discourage investigation into the invention claimed. In re Fulton, 391 F.3d 1195, 1201 (Fed.Cir. 2004). In this case, we agree with the district court that Puno does not merely express a general preference for pedicle screws having a shock absorber effect. Rather, Puno expresses concern for failure and states that the shock absorber feature decrease[s] the chance of failure of the screw or the bone-screw interface because it prevent[s] direct transfer of load from the rod to the bone-screw interface. Puno col.3 ll.64-67 (emphasis added). The district court found that the addition of Anderson's compression member to Puno's device would have eliminated or reduced the device's desired shock absorber effect, which then would increase the chance that screw and bone-screw interface failure would occur. Ensnarement Order, 526 F.Supp.2d at 172. The causal relationship between rigidity and screw failure described in Puno is supported by the testimony of DePuy's expert, Dr. Erik Karl Antonsson, see J.A. 5546-47, 5555 (testifying that rigidity increases the likelihood of screw breakage or failure). Medtronic does not specifically challenge that testimony on appeal. Rather, Medtronic's challenge to the conclusion that Puno teaches away from a rigid screw is directed at other teachings in the prior art, which, in Medtronic's view, would have motivated a person of ordinary skill to look past Puno's warning regarding screw failure. First, Medtronic directs us to an opinion of this court in a different case, in which we construed the word operatively in the phrase lower bone interface operatively joined to said bone segment in Puno's claim 5 to mean effective to perform posterior stabilization of the spine rather than micro-motion, proffered by Medtronic in that case to mean `limited motion' between the anchor and the bone. Cross Medical Prods., Inc. v. Medtronic Sofamor Danek, Inc., 424 F.3d 1293, 1305 (Fed.Cir.2005). According to Medtronic in the present appeal, our claim construction in Cross Medical shows that Puno's screws are not limited to micro or limited motion and that Puno's screws can therefore be rigid. The district court rejected this argument, noting that it was not clear that posterior stabilization and micro-motion were mutually exclusive, and regardless of the construction of the claims, that Puno's specification taught away from a rigid screw. Ensnarement Order, 526 F.Supp.2d at 172 n. 13. We agree with the district court. Nothing in our construction of the word operatively in Cross Medical specifies what degree of rigidity is needed between Puno's anchor seat and vertebrae to achieve posterior stabilization, or that Puno's shock absorber effecta stated advantage of the patentis incompatible with achieving posterior stabilization. The claim construction of the word operatively in no way overshadows the specification's warning against increased rigidity. Second, Medtronic points to U.S. Patent No. 4,946,458 (Harms patent), which lists the same inventors as those on the '678 patent and discloses how certain fasteners may be tightened or loosened as desired to achieve either a substantially stiff connection or a desired dampening movement. Harms patent col.5 ll.8-16. The Harms patent is silent, however, as to why a person of ordinary skill would have desired either of these rigidity levels, much less why a rigid connection would have been selected in the face of Puno's warning against such rigidity. Finally, Medtronic submits that a third patent, which lists Dr. Rolando Puno as a co-inventor, teaches a screw-and-rod system with an intermediate amount of rigidity. U.S. Patent No. 4,805,602 col.1 ll.58-60 (Puno '602 patent). This teaching, in Medtronic's view, would have motivated the creation of a rigid screw. But the Puno '602 patent explains that this intermediate amount of rigidity represents a trade-off between the advantages and disadvantages of wired implant and plate systems. Id. Whereas wired implants have the advantages of ... decreasing rigidity, id. col.2 ll.55-58 (emphases added), the use of plates with the screws is more rigid than the wired implants and ... can cause dislocation or even shearing of the screw, id. col.2 ll.64-67 (emphases added). The Puno '602 patent consistently views low rigidity as an advantage and high rigidity as a disadvantage, one that should be avoided whenever possible. The Puno '602 patent thus bolsters, rather than undermines, the district court's finding that the prior art teaches away from rigid pedicle screws. For the foregoing reasons, we conclude that the district court correctly found that Puno, viewed against the backdrop of the collective teachings of the prior art, teaches away from a rigid pedicle screw encompassed by the hypothetical claim, such that a person of ordinary skill would have been deterred from combining Puno and Anderson in the manner that Medtronic proposes. We also believe that certain secondary considerationsfailure by others and copyingsupport the view that this combination would not have been obvious at the time of invention. The district court found that when Medtronic set out to design a rigid pedicle screw in 1991after the '678 patent's 1989 priority date but before it was issued and published in May 1993Medtronic's engineers initially settled on a design that involved using a rod, not a compression member, to exert pressure on the screw head. Ensnarement Order, 526 F.Supp.2d at 174-75. Medtronic's engineers were focused on solving the same problem as the '678 patent making Puno's device more rigidand were also aware of compression members analogous to those found in Anderson. Id. at 174; J.A. 5532. As late as April 1993, Dr. Kevin Foley, a member of the Medtronic team that had been working to develop a rigid pedicle screw, considered their alternate design (with no compression member) to be the best solution for making Puno's device more rigid. [1] J.A. 5534. When the '678 patent issued the following month, however, Medtronic's team suddenly changed direction and decided to insert a compression member between the rod and the screw head, in the manner disclosed in the '678 patent. Id. This new design eventually became what is now the accused Vertex® model. The district court inferred from these facts that Medtronic relied on and copied the patent's compression member limitation. Ensnarement Order, 526 F.Supp.2d at 175. On appeal, Medtronic argues that it did not copy the patent but tried, albeit unsuccessfully, to design around the patent's spherically-shaped limitation to avoid infringement. But Medtronic does not allege that it independently conceived the idea of adding a compression member to a pedicle screw; indeed, Medtronic does not specifically deny copying the patent's compression member concept. Because the addition of a compression member to a pedicle screw is what Medtronic argues would have been obvious, we agree with the district court that Medtronic's initial attempt at making a rigid pedicle screw without a compression member, together with Medtronic's prompt adoption of the claimed feature soon after the patent issued, are relevant indicia of nonobviousness. See Graham, 383 U.S. at 17-18, 86 S.Ct. 684 (stating that secondary considerations may give light to the circumstances surrounding the origin of the subject matter sought to be patented). For the foregoing reasons, we hold that the hypothetical claim would not have been obvious in view of Puno and Anderson and, therefore, the district court properly denied Medtronic's ensnarement defense. [2]