Wednesday, July 17, 2013

Board reverses obviousness when rejection failed to show the combination used "known methods"

Takeaway: The Applicant appealed an obviousness rejection of a medical infusion pump. The rejection involved combining a mechanism constrained to linear motion with a rotary gear. The Examiner's rationale for the combination: the gear was "a known structure used with shape memory wires to control the flow of gases and liquids." On appeal, the Applicant argued that this rationale was insufficient for obviousness, absent a reason to combine a linear mechanism with a rotary gear. The Applicant also attacked the Examiner's bare assertion that the linear mechanism could be modified to use a gear instead, by pointing out a number of considerations that the Examiner had not addressed, including "which elements in the linearly actuated pumping mechanism the rotating gear is to be attached to and acted upon." The Board reversed the rejection because the Examiner did not explain how the proposed combination of elements would be accomplished, and thus "falls short of showing that the proposed combination could have been done according to known methods." (Ex parte Nason, PTAB 2013.)

Details:

Ex parte Nason
Appeal 2011007641; Appl No. 11/726,330; Tech. Center 3700
Decided:  April 15, 2013

The application on appeal was titled "Shape Memory Alloy Wire Driven Positive Displacement Micropump with Pulsatile Output." A representative claim on appeal read:
     1. A method of using an apparatus having a housing to deliver a fluid medication to a user, comprising the steps of:
     subjecting a shape memory wire within the housing to a first material condition, ... ; and
     subjecting the wire to a second material condition;
     wherein the shape memory wire is operatively coupled to a gear within the housing; and
     the gear comprises teeth and is operatively coupled to a fluid pump within the housing such that when the wire produces the work stroke as a consequence of a transition between the first and second material conditions, the gear is rotated such that the fluidpump generates a fluid flow that delivers the fluid medication from the apparatus to the user.
Fig. 9A (below) shows one embodiment:
During prosecution, the Examiner rejected the independent claims as obvious.The rejection relied on the primary reference Idriss (shown below, left) for the shape memory wires (shown in blue), housing, and fluid pump. In Idriss, the wires moved a slider 3 via a magnet 41, and the slider movement allowed fluid to flow through a port in the slider 3.
Idriss
AbuJudom
The rejection then relied on a secondary reference AbuJudom (shown above, right) to show the remaining element: a gear (shown in red) coupled to the shape memory wires (shown in blue). In AbuJudom, the wires 30, 32 moved the gear 46, which opened damper 12 and allowed fluid to flow.

As a reason for combining, the Examiner asserted that AbuJudom's gear was "a known structure used with shape memory wires to control the flow of gases and liquids."

The Applicant argued that this rationale was improper because adding a gear would render Idriss' pump unsatisfactory for its intended purpose. The Applicant noted that Idriss specifically described the slider as being "constrained for essentially linear movement in the directions of the arrow 30." Idriss also taught that this linear geometry produced a pulse magnitude that was repeatable and fixed. Thus, "the introduction of a rotating gear with teeth will compromise the operability of this mechanism, namely by introducing rotational forces which will oppose, or at the very least, hinder the linear forces and elements."

The Examiner maintained the rejection in a Final Office Action which addressed the Applicant's arguments as follows:
The Examiner finds no merit to the argument that a gear is not capable of delivering a discrete and metered amount of fluid medication or a repeatable and fixed pulse, the linearity of the device is not removed, just how the linear force is applied to the slider. One of ordinary skill in the art would be perfectly capable of utilizing a gear in the above combination while maintaining all the design considerations of Idriss that make it novel.
On appeal, the Applicant argued that the rataionale of a gear being a "known structure" –  without an objective reason to combine Idriss linear mechanism with AbuJudom's rotary gear – was not sufficient to establish a prima facie case of obviousness. The Appeal Brief repeated the "unsatisfactory for intended purpose" argument, along with additional technical explanation:
Because the rotational forces that are produced by a rotating gear with teeth are incompatible with the linear forces that the Idriss' pumping mechanism uses to control its work stroke, the mechanical coupling of such a gear to the Idriss device would compromise the operability of the device unless Idriss somehow taught or suggested for example: (1) how and where a rotating gear could be attached on the linearly actuated pumping mechanism; (2) which elements in the linearly actuated pumping mechanism the rotating gear is to be attached to and acted upon; and (3) how and where the existing elements within the linearly actuated pumping mechanism are to be rearranged and/or removed in order to accommodate the introduction of a rotating gear with teeth.
The Applicant then asserted that Idriss included no such teachings.

The Examiner's Answer responded to the Applicant argument by explaining one advantage of a gear: wire movement is magnified or diminished through the use of larger or smaller gears, which in turn resulted in "greater disbursement of a smaller system (large gear) or greater precision (smaller gear)."

The Board reversed the obviousness rejection, explaining that "the mere fact that AbuJudom described a gear coupled to shape memory wires to control fluid flow is not a reason to add a gear to Idriss’ device." The Board acknowledged KSR's familiar elements/known methods/predictable results rationale. However, the Board noted that here the Examiner failed to make the required "known methods" finding, since he did not explain how the proposed combination of elements would be accomplished.

My two cents:  I don't have statistics to back this up, but I'm confident in saying that when the Board quotes KSR's familiar elements/known methods/predictable results rationale, they usually affirm. And I'm usually disappointed by the Board's handwaving rather than fact-finding about the "known  methods" piece of the analysis. So I was happy to see a reversal based on a failure to show that the combination used "known methods."

The Applicant definitely helped the Board to see this deficiency in the rejection, by making detailed technical arguments about how the features from the two references just didn't fit together very well. Now, a lot of Applicants make the pieces-don't-fit argument but fail to account for modifications that a POSITA would make in fitting them together. This usually results in a reminder from the Board that obviousness does not require one feature to be "bodily incorporated" into another.

Looks like the Applicant here put a lot of thought into how a POSITA would go about fitting the pieces together. The Applicant's technical discussion convinced me – and the Board – that the fit between the pieces was so far off that the combination did not use "known methods" to combine the pieces.

2 comments:

  1. "And I'm usually disappointed by the Board's handwaving..."

    Prepare to be disappointed. A lot.

    They actually got this one right though. You know what they say about blind squirrels.

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  2. Hi Karen,

    Thank you for posting this case. I went into PAIR and read the whole Appeal Brief. It is a very well argued case.

    I am just a young attorney who is still learnig the ropes. I found this case very helpful.

    Please keep pointing out such helpful cases.

    ReplyDelete