Takeaway: The Applicant appealed an obviousness rejection of claims directed to a process of manufacturing stents. Though the Final Office Action relied on advantages taught by the secondary reference, the Advisory Action also mentioned advantages disclosed in the Applicant's specification. The Appeal Brief argued that these Applicant-known advantages actually showed that the secondary reference was non-analogous art. The Board affirmed the obviousness rejection. Though the Decision mentioned advantages taken from the secondary reference, the Board also appeared to impermissibly rely on the Applicant-known advantages as a reason to combine. (Ex parte Sciver, PTAB 2014.)
Ex parte Sciver
Appeal 2012011728; Appl. No. 12/748,271; Tech. Center 1700
Decided: October 31, 2014
The application was directed to systems methods for coating a stent with a drug.
A simplified system diagram from a related application is shown below. Stent 10 rotates about mandrel 24 via motor 340. Print head 210, 220 uses acoustic pulses to eject droplets of a coating onto the stent 10.
11. A method of depositing a substance on a stent, comprising:This independent claim was rejected as obvious over Teichman and Hopkins. Teichman taught a method of coating stents, and the Examiner relied on Teichman for all limitations except the material of the mandrel body. The Examiner relied on Hopkins "Carbide mandrel for micro extrusion of metals" for the carbide mandrel body. As a reason for the combination, the Examiner pointed to an advantages of carbide taught in Hopkins: "sufficient hardness to be practically wear resistant." The Examiner asserted that using this material would be "similarly useful and applicable to [Teichman's] analogous device."
positioning the stent 10 on a mandrel 24 for supporting the stent 10, the mandrel 24 comprising an elongated body for insertion into a longitudinal bore of the stent, the body comprising carbide;
depositing a substance on the stent; and
imaging the stent or the substance being deposited,
wherein the stent is light-colored and the elongated body is dark-colored or black.
(Numbers and emphasis added.)
In an Advisory Action, the Examiner expanded upon the rationale for the combination by referring to the Applicant's own specification, as follows:
The Examiner notes that page 7, lines 10-15 of the instant specification recites "carbide is used as the mandrel material to provide the mandrel with precise dimensions and dimensional stability over time and temperature. Since a carbide mandrel generally does not bend (it breaks instead of bending), the dimensional stability of an intact mandrel can be ensured. Additionally, a carbide mandrel can be machined without warping; this is difficult to do with many other materials because the mandrel is relatively thin and long."On appeal, the Applicant made several arguments against the combination. First, the references were in different fields: coating a medical device and microextrusion of metals. Next, the problem of Hopkins – softening of the mandrel resulting from the high temperatures of extrusion – was not relevant to Teichman, since Teichman did not indicate that softness is bad or hardness is important. Also, Hopkins' focus was a specific geometry for carbide mandrels to avoid a problem with thermal expansion during the extrusion process, and this geometry was irrelevant to Teichman, which did not relate to metal extrusion.
The Applicant summarized these points as follows:
There would not, therefore, have been any reason (such as teaching, motivation or suggestion) why one of ordinary skill would have combined the mandrel of Hopkins into the device of Teichman. Likewise, there would not have been any reason (such as teaching, motivation or suggestion) why one of ordinary skill.The Appeal Brief then went on to rebut the Examiner's position that wear resistance, as taught by Hopkins, would be an advantage in Teichman's mandrel. According to the Applicant, wear resistance in Hopkins referred to "an increased resistance to the flow of liquid metal" during a metal extrusion process. Teichman's mandrel was used to form a stent and did not involve the flow of liquid metal. Therefore, a POSITA would not view Hopkins' teaching as desirable or beneficial for forming the stent in Teichmans.
The Appeal Brief also commented on advantages of carbide mandrels which the Examiner had quoted from the Applicant's own specification:
This evidence from Applicants' own specification strengthens Applicant's position that Hopkins is not analogous to the present application. Indeed, there is no evidence that the alleged mandrel of Hopkins is "relative thin and long" or that Hopkins is trying to avoid warping during manufacture [as described by Applicant]. Nor is the dimensional stability of the mandrel [as described by Applicant] a concern in Hopkins ... Accordingly, Hopkins is non-analogous and not pertinent to the problem.
In the Answer, the Examiner reiterated his previous positions, but also responded to Applicant's characterization of Hopkins as non-analogous. After first citing to "reasonably pertinent" test for analogous art, the Examiner explained as follows:
Hopkins is pertinent to the particular problem with which the Applicant was concerned, since Hopkins clearly discloses [in the Abstract] the carbide mandrel is made from sintered carbide material which has a softening temperature significantly higher than the temperatures experienced during the extrusion process and sufficient hardness to be practically wear resistant.No Reply Brief was filed.
The Board affirmed the obviousness rejection, referring to the hardness and wear properties taught in Hopkins and relied on by the Examiner as a rationale for combining. However, the Board's rationale also referred to advantages taught in the Applicant:
Appellants have not provided persuasive technical reasoning or credible evidence why one of ordinary skill in the art would not have, using no more than ordinary creativity, predictably used a conventional carbide material for a mandrel as exemplified in Hopkins for the supporting mandrel of the prior art process stent coating process of Teichman, for the same/similar advantanges as discussed by Appellants to achieve a dimensionally stable mandrel (e.g., Ans. 6–8; Br. generally). See KSR, 550 U.S. at 421 (“A person of ordinary skill is also a person of ordinary creativity, not an automaton.”).My two cents: The Board's mention of advantages taught by the Applicant was sloppy and confusing at best, impermissible hindsight at worst.
Did the Board view an advantageous property of a carbide mandrel in the Brief as an admission of a property known to a POSITA? If so, the Board was wrong, since the Brief made it clear these properties were taken from the Applicant's Detailed Description.
If the Board knew it wasn't an admission, why bring it up at all? Advantages disclosed by the Applicant are not relevant to obviousness. So the mention of Applicant-known advantages in the Decision either muddied the waters or it was impermissible hindsight.