Monday, August 26, 2013

Board reveses obviousness of cardiac operation method when Examiner relies on statements in reference about suitability of device for operation

Takeaway: The Applicant appealed a claim to a "method for performing operation on a cardiac valve of a heart while the heart is beating." The Applicant argued that the operations disclosed in both references were not beating heart operations and instead were operations that required cardiopulmonary bypass. The Examiner maintained that the primary reference specifically described its perfusion catheter as being used while the heart was beating. The Board, finding that the Examiner had read too much into this teaching, reversed. The Board found that suitability of a device during beating heart operations generally was not a teaching of the claimed method step in the claimed beating heart operation. (Ex parte Lambrecht, PTAB 2012.)

Details:

Ex parte Lambrecht
Appeal 20100067805; Appl. No. 11/115,064; Tech. Center 2700
Decided: March 5, 2012

The application on appeal involved cardiac valve procedures and devices. The independent claim on appeal was a method of use for a cardiac valve:

     1. A method for performing an operation on a cardiac valve of a heart while the heart is beating, comprising the steps of:
     a) placing at least one temporary valve in a flow path of a blood vessel downstream from said cardiac valve, said temporary valve being operative to effect greater antegrade flow than retrograde flow through said vessel;
     b) placing at least one temporary filter in said flowpath downstream from said cardiac valve and within one of the ascending aortia and aortic arch of a patient, said filter being operative to restrict the passage of emboli while allowing blood to flow through said vessel; and
     c) resecting at least a portion of the cardiac valve with the temporary valve and temporary filter as positioned within said flowpath.
(Emphasis added.)
The Examiner found the claim obvious using a primary reference Macoviak for steps (a) and (b) and a secondary reference Stevens for step (c). As a motivation for adding the resecting step from Stevens to the procedur of Macoviak, the Examiner provided "in order to catch debris and avoid embolism," as taught in the second reference.

On appeal, the Applicant argued that several limitations were not disclosed by the combination, including an operation performed "while the heart is beating." The Applicant also argued that a POSITA would not look to modify the cardiac operation of the primary reference:
One of ordinary skill in the art would not look to a perfusion catheter that is used when the heart is stopped, as in Macoviak, in developing a system or method steps for performing surgery on a heart valve with the heart beating, as in the claimed invention. The perfusion catheter features of Macoviak are directed to fundamentally different types of cardiac procedures fiom operations that are to be conducted on a beating heart and that involve valve resection.
The Examiner addressed this argument in the Answer by noting that the relied-on section of the primary reference also taught that the perfusion catheter could be used in "beating heart" operations. The relied-upon section stated:
Therefore, what has been needed and heretofore unavailable, is a catheter device for standard open chest surgery and for use in minimally invasive medical procedures that is simple and relatively inexpensive. One which is capable of isolating the circulation of the arch vessels, while still allowing the heart to perform the function of perfusing the body or alternatively one that can be used in conjunction with an extracorporeal circuit. The present invention solves these problems as well as others.
The Applicant filed a Reply Brief characterizing the rejection as "an attempt to create a device that
might be usable in the claimed manner without any disclosure in either reference of the rejection of method steps." The Applicant then explained that the claimed operation was performed on a beating heart while both of the operations described in the references required a cardiopulmonary bypass. Because of this fundamental difference, the Applicant concluded that "it would not be possible to come up with the claimed method of performing an operation on a cardiac valve while the heart is beating by any combination of the Macoviak and the Stevens references."

The Board found this issue dispositive and reversed the rejection. The Board explained that Macoviak's statement about the suitability of a device during beating heart operations generally was not a teaching of a particular method step in a particular beating heart operation.
The cited disclosure addresses Macoviak’s characterization of the versatility of the disclosed devices, by virtue of their capability to be used both in procedures in which the heart continues to perfuse the body (i.e., continues to beat) and in procedures in which an extracorporeal circuit is used to perfuse the body. The text of Macoviak alluded to by the Examiner does not teach or suggest that all procedures for which the disclosed devices may be used may be performed while the heart is beating.
My two cents: This case (unlike most) does seem to be about the teachings of the reference, and the Examiner read too much into the reference. The Examiner took a teaching that a catheter device is useful during a class of cardiac operations (those performed with a beating heart) and stretched it into something it was not: disclosure of the claimed cardiac operation (operation on a cardiac valve while the heart is beating). A subtle point, and kudos to the Applicant for making a compelling argument.

If this was a device claim, the Applicant might run into problems with functional language being ignored as intended use. But this is a method claim, and this one is all about use. And the Board found that the references, alone or in combination, simply didn't teach the claimed use.

Finally, I note that nobody raised the issue of whether the phrase "while the heart is beating" – which appears in the preamble – should get patentable weight.

4 comments:

  1. Finally, I note that nobody raised the issue of whether the phrase "while the heart is beating" – which appears in the preamble – should get patentable weight.
    Why should it have been?

    While I try to keep meaningful limitations out of the preamble, I'm not afraid to put them in there either. The "while the heart is beating" limitation clearly impacts the claimed steps.

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    1. >"while the heart is beating" limitation
      >clearly impacts the claimed steps.

      Yep, and therefore should be given patentable weight.

      OTOH, can you think of any specific reason *not* to make sure it gets patentable weight by putting the limitation in one or more of the steps, e.g.,

      a) WHILE THE HEART IS BEATING, placing at least one temporary valve in a flow path of a blood vessel downstream from said cardiac valve,

      Other than the generalized reason that any limitation gives an accused infringer something to argue about?

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  2. I'm sorry for my ignorance, but can this claim be enforced? who can be a liable infringer?

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    Replies
    1. Are you referring to the medical use exception under 287(c) ?

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