Ex parte Parker
Appeal 2009009173; Appl. No. 09/815,567; Tech. Center 3700
Decided March 11, 2011
The technology on appeal involved an "introducer sheath," used in medical procedures like angioplasty. The independent claim on appeal included an inner tube, a wire coil wound around the inner tube, and two outer tubes of differing hardness.
The Examiner rejected under § 103, using a primary reference (Horrigan) that disclosed everything in the claim, except it used a wire braid rather than a wire coil. The secondary reference (Park) disclosed a sheath with "various forms of braid and coil reinforcements," along with "the equivalence of a braid or a coil or a combination of one or more of each for reinforcement of an intravascular device for use in an environment of increasingly small diameters." The Examiner used this to advance the substitution rationale:
It would have been obvious ... to have substituted the wire braid 35 of Horrigan et al. with a braided wire coil, a flat wire coil or a round wire coil as disclosed by Park et al. to have facilitated the manufacture of the catheter or sheath with a diameter suitable for application in an environment of increasingly small diameters.
Before appeal, the Applicant submitted declaration evidence to show that coils and braids are not equivalent or interchangeable. The declarations also explained how computer simulation using finite element analysis had shown the claimed coil was superior to the braid described in the primary reference. The Examiner was not persuaded, so the Applicant appealed.
In the Appeal Brief, the Applicant referred to the statements in the declaration, and explained their significance as follows:
Clearly, the [finite elements analysis] test showed that the sheath having a coil reinforcement has bending angles at which the sheath having a braid reinforcement would be unusable. This difference can be critical when attempting to position a medical interventional device, such as a stent, at branched or otherwise tortuous area of the vasculature. In many such cases, placement utilizing a coil-reinforced sheath would be successful, while an attempted placement with a braid-reinforced sheath would fail.
The Board agreed with the Examiner's substitution rationale, finding that "the use of a wire coil in an introducer sheath involves the simple substitution of one type of reinforcement (a braid) for another known reinforcement in order to achieve the predictable result of a sheath of small diameter for use in navigating small blood vessels."
The Board noted the Applicant's disagreement with the Examiner on whether or not the secondary reference (Park) taught the equivalence of braids and coils as "alternative types of reinforcement structures utilized in intravascular devices." However, the Board found that even if the Examiner's finding of equivalence was in error, it would be obvious to balance design trade offs to select either a coil or a braid for a reinforcement. The Board based this, in part, on the Applicant's admissions that differences between coils and braids were well understood:
Appellant admits that the properties of and differences between the two types of support structures were known by persons of ordinary skill in the art. See App. Br. 10 (a braid’s torque transmitting ability “is well known to those skilled in the art”); Reply Br. 4 (“Appellant repeatedly emphasized, with both argument and evidence, that those skilled in the art recognize that there is a distinct difference between various types of reinforcements utilized in medical devices.”); Oral Hearing Transcript at 4:16-21 (discussing the high level of knowledge in the art at the time of the invention); id. at 15:12 – 16:5 (same); Spec. 2:1-7 (paraphrasing Parker, col. 1, l. 64 – col. 2, l. 4, and describing that reference as disclosing a sheath with improved kink resistance due to a coil reinforcement). Accepting as fact that ordinary artisans recognized that a coil reinforcement provides predictable and markedly better results than a braid, this, in itself, is a reason to modify Horrigan’s braid-reinforced device. At most, Appellant’s arguments suggest that the Examiner’s proposed modification would require one of ordinary skill in the art to balance certain design trade-offs in selecting the type of reinforcement. However, this does not render the claimed invention non-obvious. Cf. KSR Int’l Co. v. Teleflex Inc., 550 U.S. at 421 (“If [pursuing known options within the ordinary artisan’s grasp] leads to the anticipated success, it is likely the product not of innovation but of ordinary skill and common sense.”)
My two cents: There's a lot going on in this case – seven Office Actions before the case made it to the Board. The Applicant did a lot right. For starters, the Applicant pulled the case from appeal the first time and introduced declaration evidence. The first three responses included a lot of sweeping statements about the art which could be considered "mere attorney argument" by the Board. After that, the Applicant started submitting declaration evidence – a total of four different 1.132 declarations by four different non-inventor experts over the course of the next three years of prosecution.
Today's post focuses on one narrow issue: how the Applicant's argument and evidence about advantages – designed to overcome an obviousness rejection – apparently did just the opposite.
The Applicant fought the same combination of references since the very first Office Action. The substitution rationale was also present since the first Office Action: "mere substitution of one functional equivalent for another" and "selection of any of these known equivalents would provide a cathether section with improved kink resistance as taught by [primary reference.]"
I think the Applicant got stuck, very early in prosecution, on the Examiner's statements about the equivalence of braids and coils. And in refuting the equivalence, the Applicant walked into what turned out to be an obviousness trap. OK, there are differences between coils and braids when used in stents. OK, a coil like the one claimed by Applicant is superior. But if those differences are known (and Applicant admitted they were) then picking the appropriate one can be viewed as a design trade off like those made by engineers every day, as opposed to an invention worthy of a patent. Worse yet, if the superiority of a coil is known (and Applicant's background admitted this in describing another prior art reference) then it's not even a trade off to be investigated by engineers – this known superiority can be viewed as an actual reason to modify the primary reference to use the superior coil rather than the inferior braid.
There's a lot more to this case. There was a dissenting opinion that offers another viewpoint, one which I find compelling. I'll discuss the Ex parte Parker dissent in a future post.
Postscript: The Applicant has appealed the BPAI decision to the Federal Circuit. The assignee is Cook Medical.