IP Law Daily, PATENT—P.T.A.B.: Director denies institution of five iRhythm IPRs targeting Welch Allyn’s heart monitor patents, (Jun 10, 2025)

By Saurabh Kashyap, B.A., M.A., LL.B., LL.M.

IRhythm’s decade-long delay in challenging known patents outweighed factors favoring review.

United States Patent and Trademark Office (USPTO) Acting Director Coke Morgan Stewart denied the institution of five inter partes review (IPR) petitions filed by iRhythm Technologies, Inc. against patents owned by Welch Allyn, Inc., exercising discretionary authority under 35 U.S.C. § 314(a). Despite procedural factors that typically favor institution, such as a district court trial date well after the projected PTAB decision deadline, the Director concluded that iRhythm's longstanding awareness of the patents, coupled with its failure to timely seek review, created settled expectations that weighed strongly against the institution and warranted discretionary denial (iRhythm Technologies, Inc. v. Welch Allyn, Inc., IPR2025-00363 (P.T.A.B. Jun. 6, 2025)).

Background. iRhythm filed five petitions between February and March 2025, challenging all claims of five Welch Allyn patents. These included U.S. Patent Nos. 10,159,422 (the ’422 patent), 8,965,492, 9,155,484, and two separate petitions involving 8,214,007. The patents relate to wearable cardiac and physiological sensors, including features such as flexible printed circuit boards, disposable electrodes, and reusable communication-processing modules. The claims describe both methods for manufacturing and the resulting physiological sensor devices.

In its petition challenging the ’422 patent (IPR2025-00363), iRhythm asserted three obviousness grounds based on Matsumura (JP2004/121360), Jensen (U.S. Pub. No. 2003/0149349), and Ozguz (U.S. Pub. No. 2005/0096513), each combined with the general knowledge of a person of ordinary skill in the art (POSA). iRhythm alleged that the prior art collectively taught the claim limitations and that the ’422 patent offered no meaningful innovation over known combinations of disposable monitoring components and wearable electronics.

The petition relied heavily on an omnibus expert declaration from Dr. Jason Heikenfeld, Ph.D., which was incorporated by reference across all five petitions. The declaration spanned more than 500 pages and included over 1,700 paragraphs of analysis, much of which was cross-referenced between different IPRs and supported by over 50 exhibits, including textbooks, academic papers, and websites.

Patent owner’s discretionary denial request. Welch Allyn filed a separate discretionary denial request in each IPR under the USPTO's March 26, 2025, "Interim Processes for PTAB Workload Management" guidance. The request invoked both traditional Board precedent and the Director's expanded discretion to manage PTAB's workload in the face of redundant or burdensome proceedings.

Welch Allyn advanced three primary arguments. First, it contended that the petitions failed to meet the particularity requirements of 35 U.S.C. § 312(a)(3) by relying on generalized assertions about POSA knowledge without identifying clearly where and how each limitation was taught. It drew heavily on the Board’s reasoning in Adaptics Ltd. v. Perfect Co., IPR2018-01596 (P.T.A.B. March 6, 2019) (informative), where an overreliance on poorly supported "catch-all" citations led to discretionary denial.

Second, Welch Allyn criticized the petitions' reliance on Dr. Heikenfeld's expert declaration. It argued that many key claim elements were not mapped to prior art references but rather to non-prior art documents—such as Exhibit 1035, a 2006 textbook; Exhibit 1021, a 2013 article; and Exhibit 1043, a 2019 physics manual. These materials, it argued, were improperly used to support assertions about the state of the art without being authenticated as prior art. Furthermore, the expert's declaration cross-referenced different sections across multiple IPRs, requiring the Board and the patent owner to "excavate" the analysis from a "morass" of interwoven citations.

Third, Welch Allyn pointed to iRhythm's prior awareness of the patents at issue. As early as 2013, iRhythm had cited the application that was later issued as U.S. Patent No. 8,214,007 in an information disclosure statement submitted during the prosecution of its own patent application (Exhibits 2001 and 2002). Despite this, it waited more than a decade, until after Welch Allyn filed suit in the District of Delaware in early 2024, to challenge the patents. Welch Allyn argued that this delay created settled expectations and strongly favored denial under the Director's 2025 guidance.

IRhythm’s opposition. In opposing the discretionary denial request, iRhythm argued that multiple factors typically disfavor discretionary denial. Chief among them was the timing of the PTAB and district court proceedings. The projected final written decision date for the PTAB was August 12, 2026—well before the district court trial date of March 22, 2027. iRhythm also emphasized that the parties had made only modest investments in the district court case and that a stay was likely if the PTAB were to institute a review.

IRhythm defended its use of Dr. Heikenfeld's expert testimony, arguing that it complied with 37 C.F.R. § 42.65(a) and was properly limited to clarifying what a POSA would understand. It also noted that, while the declaration referenced many exhibits, the expert consistently linked his conclusions to factual bases, and the use of general knowledge was consistent with PTAB practice.

Director’s decision. On June 6, 2025, Acting Director Coke Morgan Stewart issued a consolidated decision denying the institution of all five IPRs. The decision acknowledged that certain Fintiv factors, such as the relative timing of the PTAB decision and the district court trial, favored the institution. The Director also found no misuse of expert testimony. He noted that the expert's citations to background documents complied with Board rules and did not constitute improper gap-filling. The Director specifically cited Xerox Corp. v. Bytemark, Inc., IPR2022-00624 (P.T.A.B. August 24, 2022) (precedential), in affirming that a properly supported declaration that clarifies a POSA's understanding does not by itself justify denial.

Nonetheless, the Director concluded that iRhythm's delay in seeking review was a dispositive factor. The decision emphasized that "Petitioner's awareness of Patent Owner's applications and failure to seek early review of the patents favors denial and outweighs the above-discussed considerations." The Director found persuasive the patent owner's evidence that iRhythm had long known of the patent family and declined to challenge it until litigation made the issue unavoidable. This factor, taken together with the burden the petitions would impose on the Board—given their complexity and incorporation of overlapping materials—was sufficient to justify discretionary denial under § 314(a).

The Director emphasized that this denial was based on "a holistic assessment of all of the evidence and arguments presented," consistent with the USPTO's March 2025 policy directive to manage PTAB workload by declining institutions in proceedings that present a high burden relative to their policy value.

The Case is Nos. IPR2025-00363, IPR2025-00374, IPR2025-00376, IPR2025-00377, IPR2025-00378.

Attorneys: Robert Counihan (Fenwick & West LLP) for IRhythm, Inc. Erik Halverson (K&L Gates LLP) for Welch Allyn, Inc.

Companies: IRhythm, Inc.; Welch Allyn, Inc.

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