Friday, March 18, 2011

BPAI finds needle "configured to drive a suture against tissue without severing the suture" does not require the tip to sever the suture in all scenarios

Takeaway: The Applicant claimed a needle tip "configured to drive a suture against tissue without severing the suture." On appeal, the BPAI affirmed an anticipation rejection after finding that the limitation "excludes only those structures that would sever a suture in every instance upon being driven against tissue" and "does not mean that in all circumstances the tip severs the suture material."

Details:

Ex parte Strkyer Endoscopy
Appeal 2009-010003; Appl. No. 10/680,079; Tech. Center 3700
Decided   December 22, 2010

This application involved a surgical apparatus for delivering and retrieving a suture. Claim 36 included a cannula (hollow tube for insertion into a body cavity), and the disputed limitation was "wherein a portion of a distal end of the cannula is configured to drive a suture against tissue without severing the suture."

The Examiner rejected claim 36 as being anticipated by Violante, which disclosed a surgical instrument including a hollow needle for delivering suture thread to a body location. According to the Examiner, the needle tip 42 in FIG. 2 corresponds to the "distal end of the cannula is configured to drive a suture against tissue without severing the suture."

Neither FIG. 2 nor any other figure in Violante showed the needle tip in detail. But in the Appeal Brief, the Applicant pointed to the portions of the specification which described the needle tip. These portions described the needle tip as "beveled and sharpened" and "present[ing] a sharpened edge that may be employed in cutting of suture material." The Applicant argued that "the bevel causes the interior surface of the trailing end of the bevel to be sharply acute," which presents "a distinct danger that a suture ... will be severed during insertion." Thus, Violante's needle tip was not "configured to drive a suture ... without severing."

In the Answer, the Examiner responded that Violante met the claim limitation in two ways. First, while the point of the needle tip is sharp, the face of the bevel is blunt. Thus, the face of the bevel is "a portion of the distal end of the cannula" which can be applied to drive the suture "without severing." Furthermore, even the sharp portion of the beveled tip "forms a narrow point that would not likely engage and sever a suture." (Emphasis added.) Since Violante describes the needle as being used for tissue penetration "there is little or no danger that a suture inserted through the use of the device of Violante would be severed during insertion."

The Applicant responded to this last point in the Reply Brief.  While acknowledging that a beveled and sharpened tip can penetrate tissue, the Applicant argued that the reference did not disclose "how the suture can be inserted through tissue without being severed by the sharpened edge." According to the Applicant, the reference did not explain how the needle tip actually interacts with the suture during tissue puncturing. 

The Board affirmed the anticipation rejection, but seemed to apply a slightly different rationale. The Board agreed with the Examiner that some portions of the needle tip would be incapable of severing the suture. But while the Examiner relied on the face of the bevel as that portion, the Board instead looked to the "side of Violante's tip that is not beveled". That side "remains unmodified and thus retains the curved shape of the cylindrical tube's outer surface." The Board found that this curved portion of Violante's needle tip "would not operate to sever suture when driven against tissue."


The Board then went further to note that Violante's structure actually taught more than was necessary. According to the Board, all that was necessary to satisfy the "broadly written" claim was "a structure that in some circumstances will not sever a suture when pressed or driven against body tissue. "

[C]laim 36, as broadly written, excludes only those structures that would sever a suture in every instance upon being driven against tissue. That a "beveled and sharpened tip" includes a sharpened edge which may be useful in cutting a suture material does not mean that in all circumstances the tip severs the suture material. Indeed, the tip's ability to cut the material is not dependent solely on the tip's configuration but is also a function of other factors such as the driving force applied to the suture, the strength of the material that makes up the suture, and the tension on the suture. Violante's tip, even if
sharpened, may be driven against tissue with a force of inadequate magnitude to severe a particular suture. It is neither unreasonable nor inconsistent with Stryker's specification that the beveled and sharpened tip in Violante constitutes a structure that in some circumstances will not sever a suture when pressed or driven against body tissue. That is sufficient to satisfy claim 36.

My two cents: Was it the presence of "configured to" that led the Board to take such an expansive reading of the claim language? Under the Board's reading, a sharp needle tip meets the limitation as long as the surgeon uses minimal force and/or the suture is made of incredibly strong fiber. Does using purely functional language always result in this sort of interpretation?

To combat this you may need to recite structure that performs this function. In this case, the structure that produced the behavior of "driv[ing] a suture against tissue without severing the suture" was a "blunt heel" (274 in FIG. 42 below).


In fact, the Applicant argued this distinction in the Appeal Brief:
This feature is very clearly shown in Figures 42 and 43, and is described in the accompanying text of paragraph 222, which reads "[tlhe cannula is preferably blunted or rounded off at 274 (see FIGS. 42 and 43) so as to minimize the possibility of damaging a suture during a tissue piercing operation, as will hereinafter be discussed in further detail." ...
Clearly, the blunt heel 274 is a feature entirely different from and independent of the beveled shape of the cannula tip.

The BPAI ignored this argument, of course
In this case, if Stryker intended that its cannula end includes the  specific structural characteristic of a "blunt heel," it could easily have amended the claims accordingly. It did not. Claim 36 requires simply that "a portion of the distal end of said cannula is configured to drive a suture against tissue without severing the suture." That feature is met in the prior art by a cannula or tube having a distal end with any portion of the distal end configured such that it does not sever suture when driven against tissue.

This feature was captured in an originally filed dependent claim. But that claim was canceled before appeal.

The first explanation of how the needle tip in the reference met the limitation didn't appear until the Examiner's Answer.

14 comments:

  1. I disagree with the Board's reasoning. If the device of the reference EVER severs the suture, then it is not configured to drive the suture without severing the suture. It is not good enough for it to only not sever it once, or in some cases. It must never sever the suture. Otherwise it is not configured not to sever the suture. (love all the double negatives)

    BAB

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  2. I agree that the BPAI's treatment of functional language here is unreasonable. It's like they take the requirement that the prior art *must necessarily always* meet the claim limitation and turn it into if the prior art *could, once, under very precise circumstances* meet the claim limitation. Can't pretty much any prior art perform a recited function if given the correct, if outlandish, circumstances? I could pass a camel through the eye of a needle if given the proper tools and motivation...

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  3. The BPAI got it right IMO. Karen's right. The Applicant should have claimed the structure itself, not what it can do. The Applicant invented only one way of performing the function, and the claim shouldn't cover all things yet to be invented that can do the function.

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  4. "the claim shouldn't cover all things yet to be invented that can do the function"

    This says nothing of whether prior art exists that can do the function. I thought 112 was more for policing undisclosed/non-enabled claim scope than 102?

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  5. >>the claim shouldn't cover all things yet to
    >>be invented that can do the function
    >
    >This says nothing of whether prior art exists
    >that can do the function. I thought 112 was
    >more for policing undisclosed/non-enabled claim
    >scope than 102?

    112 2nd (indefiniteness) can perform this policing function too.

    The recent PTO Examiner Guidelines on 112 2nd have a whole section explaining the interplay between functional language, 112 1st, and 112 2nd:

    "Notwithstanding the permissible instances, the use of functional language in a claim may fail 'to provide a clearcut indication of the scope of the subject matter embraced by the claim' and thus be indefinite. ... Unlimited functional claim limitations that extend to all means or methods of resolving a problem may not be adequately supported by the written description or may not be commensurate in scope with the enabling disclosure, both of which are required by § 112, ¶1."

    Instead of interpreting the claim limitation broadly enough to read on the prior art, seems like the BPAI could have instead issued a 112 2nd and/or 1st and refused to reach the prior art rejection.

    Most of the cases where I've seen that happen involve "purely" functional language. The limitation here -- "distal end [of a cannula] configured to" -- did contain some structure. Just nothing that actually performed the claimed function.

    The Board could have taken yet a third route here: applied 112P6 and found that the only structure disclosed in the spec was the blunt heel. From what I recall, that structure distinguishes over the reference.

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  6. This comment has been removed by the author.

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  7. "In the Answer, the Examiner responded that Violante met the claim limitation in two ways. First, while the point of the needle tip is sharp, the face of the bevel is blunt. Thus, the face of the bevel is "a portion of the distal end of the cannula" which can be applied to drive the suture "without severing." Furthermore, even the sharp portion of the beveled tip "forms a narrow point that would not likely engage and sever a suture." (Emphasis added.) Since Violante describes the needle as being used for tissue penetration "there is little or no danger that a suture inserted through the use of the device of Violante would be severed during insertion."
    "

    Obviously. Jezus. An applicant paid a lot of money to make this bogus argument.

    "The Applicant responded to this last point in the Reply Brief. While acknowledging that a beveled and sharpened tip can penetrate tissue, the Applicant argued that the reference did not disclose "how the suture can be inserted through tissue without being severed by the sharpened edge." According to the Applicant, the reference did not explain how the needle tip actually interacts with the suture during tissue puncturing. "

    Yeah because one of ordinary skill picks up on that from the get go. If it severed the suture going in then WTF would be the point in having the suture on the tool in the first place? God. Some people.

    ""broadly written" claim was "a structure that in some circumstances will not sever a suture when pressed or driven against body tissue. ""

    Obviously. Situtations like these make you wonder how some people manage to file a patent application at all on these things. Or put their shoes on in the morning.


    "The Board affirmed the anticipation rejection, but seemed to apply a slightly different rationale. The Board agreed with the Examiner that some portions of the needle tip would be incapable of severing the suture. But while the Examiner relied on the face of the bevel as that portion, the Board instead looked to the "side of Violante's tip that is not beveled". That side "remains unmodified and thus retains the curved shape of the cylindrical tube's outer surface." The Board found that this curved portion of Violante's needle tip "would not operate to sever suture when driven against tissue.""

    Meh, either is fine.

    "Does using purely functional language always result in this sort of interpretation? "

    Ever since it came into being in the late 60's/70's. Note also that this is an intended use. Not really "functional" language. The configuration is such that it may accomplish the intended use of not severing the material.

    "if Stryker intended that its cannula end includes the specific structural characteristic of a "blunt heel," it could easily have amended the claims accordingly. "

    Obviously. Gotta hold applicant's hands from point A to point B.

    "The first explanation of how the needle tip in the reference met the limitation didn't appear until the Examiner's Answer."

    That's not exactly something that every kindergartener wouldn't pick up on upon having read the claims and the references. I expect a patent professional, of which I presume there was one prosecuting, to do a lot better.

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  8. "It is not good enough for it to only not sever it once, or in some cases. It must never sever the suture. "

    Lulz, wrong. Go take some patent drafting 101.

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  9. "Instead of interpreting the claim limitation broadly enough to read on the prior art, "

    What on earth would possess the board to purposefully misconstrue a claim in this fashion? Come on Karen. They might misinterprete a claim occasionally, but they don't do it on purpose. This claim is easy pickings to construe.

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  10. "The Board could have taken yet a third route here: applied 112P6 and found that the only structure disclosed in the spec was the blunt heel. From what I recall, that structure distinguishes over the reference. "

    And from what I recall that is improper use of 112 6th in construing a claim. There is certainly no means+function language and there is no clear indication that the applicant meant to invoke such. One of those two is, so far as I'm aware, according to your lawl, required to properly invoke such. Furthermore, I haven't read the whole record but I imagine that if anything there is something on the record indicating implicitly they did not want to invoke 112 6th.

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  11. Just thought I'd point out that the application claimed priority from an issued patent (US6,629,984) already having claims directed to the "blunt heel," as well as claims much more broad in scope that do claim it functionally. For example, see claims 17 and 18, below. So they may not have felt that they had anything to gain by narrowing the claim to that specific feature, and/or, there might have been a double patenting issue. Also, there is a child app pending that is not yet published or available on PAIR.


    6629984
    17. An apparatus for receiving and passing one or more sutures, one or more tools, and combinations thereof, comprising:
    a handle having a proximal end and a distal end;
    a boss mounted on and upstanding from said proximal end of said handle, said boss defining an interior bore therethrough; and
    a cannula mounted on said distal end of said handle and said cannula having a distal end, said cannula defining an interior bore therethrough, said interior bore of said boss and said interior bore of said cannula being substantially aligned with one another;
    wherein at least a portion of said distal end of said cannula is configured to drive a suture against tissue without severing the suture.

    18. The apparatus of claim 17, said cannula having a passage;
    wherein said distal end defines an oblique angle relative to said passage, with a distal sharp tip and a blunt proximal heel;
    said blunt proximal heel defining said at least a portion.

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  12. From MPEP 2112:

    The fact that a certain result or characteristic may occur or be present in the prior art is not sufficient to establish the inherency of that result or characteristic. In re Rijckaert, 9 F.3d 1531, 1534, 28 USPQ2d 1955, 1957 (Fed. Cir. 1993) (reversed rejection because inherency was based on what would result due to optimization of conditions, not what was necessarily present in the prior art); In re Oelrich, 666 F.2d 578, 581-82, 212 USPQ 323, 326 (CCPA 1981). "To establish inherency, the extrinsic evidence 'must make clear that the missing descriptive matter is necessarily present in the thing described in the reference, and that it would be so recognized by persons of ordinary skill. Inherency, however, may not be established by probabilities or possibilities. The mere fact that a certain thing may result from a given set of circumstances is not sufficient.' " In re Robertson, 169 F.3d 743, 745, 49 USPQ2d 1949, 1950-51 (Fed. Cir. 1999).

    Here, the BPAI is arguing that there are certain instances in which the distal end MAY be used in a manner such that the tip may not sever the suture material. This is an inherency argument, which doesn't pass muster under the case law reproduced above.

    Classic BPAI BS analysis.....

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  13. I don't think anyone picked up on this, but if true, this is what disturbs me most: The blog states "The first explanation of how the needle tip in the reference met the limitation didn't appear until the Examiner's Answer." And herein lies the problem with Examination. The examiner didn't explain him/herself until prosecution was closed.

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  14. The manufacture of suture needle includes different method and strong materials like fiber are used to produce it.

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