11956428 (B.P.A.I. Jun. 15, 2012)

Ex Parte Song

Board of Patent Appeals and InterferencesJun 15, 2012

11956428 (B.P.A.I. Jun. 15, 2012)

UNITED STATES PATENT AND TRADEMARKOFFICE UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www.uspto.gov APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 11/956,428 12/14/2007 Xuedong Song KCX-1428 (64376653US01) 7454 22827 7590 06/15/2012 DORITY & MANNING, P.A. POST OFFICE BOX 1449 GREENVILLE, SC 29602-1449 EXAMINER XU, XIAOYUN ART UNIT PAPER NUMBER 1777 MAIL DATE DELIVERY MODE 06/15/2012 PAPER Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE BOARD OF PATENT APPEALS AND INTERFERENCES ____________ Ex parte XUEDONG SONG ____________ Appeal 2011-006970 Application 11/956,428 Technology Center 1700 ____________ Before JEFFREY T. SMITH, LINDA M. GAUDETTE, and DONNA M. PRAISS, Administrative Patent Judges. PRAISS, Administrative Patent Judge. Appeal 2011-006970 Application 11/956,428 2 DECISION ON APPEAL Appellant appeals under 35 U.S.C. § 134(a) from the Examiner’s decision1 finally rejecting claims 1-10 under 35 USC §103(a) as unpatentable over Pugia (US 5,631,163, issued May 20, 1997) in view of Chudzik (US 5,707,818, issued Jan. 13, 1998).2 We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM. The invention “is generally directed to a lateral flow assay device for determining the ionic strength of urine. The device can include a buffering zone with a polyelectrolyte disposed therein and an indicator zone with a pH indicator non-diffusively immobilized therein.” (Spec.3 4.) Claim 1, the sole independent claim on appeal, is representative of the invention and is reproduced below from the Claims Appendix to the Appeal Brief: 1. A method for quantitatively or semi-quantitatively determining the ionic strength of a test sample of urine, the method comprising: providing a lateral flow device comprising a fluidic medium, the fluidic medium defining a buffering zone and an indicator zone, the buffering zone including a polyelectrolyte disposed therein, the indicator zone including a pH indicator non-diffusively immobilized therein, the indicator zone being separate from the buffering zone and in fluid communication with the buffering zone, the polyelectrolyte capable of an ion-exchange with the urine so as to change the hydrogen ion concentration in the urine, the pH indicator capable of producing a signal corresponding to the hydrogen ion concentration in the urine; and contacting the test sample with a fluidic medium of the lateral flow device; determining the ionic strength of the urine based on the signal produced by the pH indicator. 1 Final Office Action mailed Aug. 2, 2010 (“Final”). 2 Appeal Brief filed Dec. 6, 2010 (“App. Br.”). 3 Specification filed Dec. 14, 2007. Appeal 2011-006970 Application 11/956,428 3 Pugia establishes that at the time of the invention, it was known in the art of determining the ionic strength of a urine sample to provide “a reagent strip[] . . . made in such a way that all the relevant reagents are diffusively immobilized together on a small porous zone on the strip” and to apply “[a] sample of urine . . . to the zone or [dip] the entire strip . . . in the urine sample to allow color to develop” to determine the ionic strength of the urine based on the signal produced by the pH indicator. (App. Br. 3). (Ans.4 3-4.) This known system operated as follows: “ions present in urine induce an ion-exchange with a polyelectrolyte, thereby introducing hydrogen ions into the urine. The change in hydrogen ion concentration is detected by a pH indicator” (Spec. 2). (Ans. 3-4.) Chudzik evidences that at the time of Appellant’s invention, it was known in the art of assaying urine samples to use “a lateral flow device comprising a fluidic medium defining a competition zone (22) and an indicator zone (readout zone 26) for processing reagent and readout indicator reagent non-diffusively deposited therein, respectively (see col. 3, lines 3-7; col. 6, lines 56-67; Figure 1).” (Ans. 4.) Chudzik explicitly states “’Non-diffusive’, as used in this respect, means that the reagent is sufficiently stable in its position under the conditions of the assay.” (Chudzik, col. 7, ll. 27-29). The Examiner finds that Chudzik teaches that “by non-diffusively depositing the reagent to the zones, the reagent is sufficiently stable in its position under conditions of the assay (col. 7, lines 21-29), which means the indicating color would last longer” (Ans. 4). The Examiner further finds that “Chudzik teaches non-diffusive[ly] immobilizing 4 Examiner’s Answer mailed May 11, 2010. Appeal 2011-006970 Application 11/956,428 4 the indicator in a specific zone of the test strip, i.e. in a form of band or a plus (‘+’) sign (see col. 6, lines 23-25), which would enhance the contrast of the color indicator” and “[t]he non-diffusive indicator helps maintain the shape of a plus (‘+’) sign or a band.” (Ans. 4). Based on the above findings of fact, the Examiner concluded “it would have been obvious to one of ordinary skill in the art to non-diffusively deposit the reagents (polyelectrolyte and pH indicator) of Pugia in buffer (competition) zone and indicator (read out) zones, respectively, as taught by Chudzik, so that the polyelectrolyte and pH indicator would be sufficiently stable in its position under conditions of the assay.” (Ans. 4.) Appellants do not dispute the above findings of fact with respect to Pugia. (See App. Br. 3-6.) Nor does Appellant disputes the above findings of fact with respect to Chudzik. (See id.) Appellant contends the Examiner reversibly erred in rejecting the claims because: [T]he conventional test strip described in Pugia et al. teaches away from such non-diffusive immobilization [of Chudzik]. Furthermore, Pugia et al. also teaches away from a method for quantitatively or semi-quantitatively determining the ionic strength of a test sample of urine by utilizing a lateral flow device having an indicator zone including a pH indicator non-diffusively immobilized therein. (Id. at 4.) “If a person of ordinary skill can implement a predictable variation, § 103 likely bars its patentability. For the same reason, if a technique has been used to improve one device, and a person of ordinary skill in the art would recognize that it would improve similar devices in the same way, using the technique is obvious unless its actual application is beyond his or her skill.” KSR Int'l Co. v. Teleflex, Inc., 550 U.S. 398, 417 (2007). Appeal 2011-006970 Application 11/956,428 5 Both Pugia and Chudzik are directed to using devices with immobilized reagents, including indicators, for assaying urine samples. As correctly observed by Appellant (App. Br. 3), Pugia differs from the claimed invention in that Pugia utilizes reagents that are diffusively immobilized together, rather than non-diffusively immobilized into zones. However, Appellant has not explained why one of ordinary skill in the art would not have (1) possessed the requisite skills to utilize the non-diffusively immobilized zones disclosed by Chadzik to improve stability, indicating color would last longer, and enhance contrast of the color indicator, and (2) had a reasonable expectation of success in so doing.5 Appellant has not persuasively demonstrated that Pugia, if modified such that the reagents were non-diffusively immobilized into zones as disclosed by Chadzik, would not have resulted in the invention as claimed. For the reasons stated above and in the Answer, we affirm the Examiner’s decision to reject claims 1-10. No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a)(1). AFFIRMED sld 5 Chadzik discloses that it was known at the time of the invention to immobilize reagents either diffusively or non-diffusively (Chudzik, col. 7, ll. 20-35) and further discloses an embodiment with diffusively-bound reagents used in a “competition zone” and non-diffusively-bound reagents in a “read out zone” (Chudzik, col. 8, ll. 5-19). This suggests interchangeability of diffusive and non-diffusive immobilization for some reagents.