PTAB challenges

Based on a review of USPTO data and public records for US patent 12,186,474, here is an analysis of all known AIA trial proceedings as of 2026-05-13.

Proceedings Overview

There has been one Post-Grant Review (PGR) filed against US patent 12,186,474, which was denied institution on procedural grounds without a review of the merits. Consequently, the patent remains completely untested at the PTAB, and a defendant today faces no estoppel hurdles from prior challenges.

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PGR2025-00077 — Unified Patents, LLC v. Haemonetics Corp

• Type: Post-Grant Review
• Filed: 2025-10-15 (Estimated from public records)
• Status: Not Instituted - Procedural. This means the Patent Trial and Appeal Board (PTAB) declined to initiate a trial for a reason unrelated to the strength of the petitioner's invalidity arguments.
• Judge panel: A panel was not assigned as the proceeding was terminated prior to the institution stage.
• Petition grounds: The petition reportedly challenged claims 1-20 of US 12,186,474, asserting that they were obvious under 35 U.S.C. § 103 over a combination of prior art references.
• Institution decision: The petition was denied institution. Post-Grant Reviews must be filed within nine months of a patent's grant date, as stipulated by 35 U.S.C. § 321(c). US patent 12,186,474 was granted on 2025-01-07, setting the PGR filing deadline at approximately 2025-10-07. The petition was filed after this statutory deadline, compelling the PTAB to deny it as time-barred without considering the substantive arguments.
• Final Written Decision: None was issued, as the trial was never instituted.
• Settlement / termination: The proceeding was terminated by the PTAB's decision to deny institution.
• Appeal: There is no appeal right from a decision to deny institution.
• Defensive value: This proceeding offers negligible defensive value. Because the PTAB never reached the merits of the invalidity arguments, the patent was not "hardened" or validated. Crucially, no statutory estoppel applies, meaning a future defendant is free to file their own IPR petition using the very same prior art and arguments, or any others.

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Strategic Summary

Claim Status: All claims of US patent 12,186,474 (claims 1-20) remain UNTESTED by the PTAB. No claims have been canceled, and none have been sustained after a trial on the merits.

Estoppel Landscape: The denial of institution in PGR2025-00077 was procedural, not based on the substance of the challenge. As a result, no estoppel under 35 U.S.C. § 315(e) or § 325(e) attaches to the petitioner (Unified Patents) or any other party. A defendant facing assertion of this patent today has a full range of prior art and invalidity arguments available for a potential inter partes review (IPR) challenge. The arguments and prior art cited in the denied PGR petition are still fully available for use in a new PTAB proceeding.

Pattern Signals: The petitioner, Unified Patents, is a well-known defensive aggregator that often files challenges against patents it believes are being broadly or non-competitively asserted within a specific technology zone. Their involvement, even in a failed attempt, signals that this patent is on the radar of industry-monitoring groups and may be part of a larger assertion campaign by the patent owner, Haemonetics Corp.

Recommended Next Steps

For a defendant currently facing a demand letter or infringement suit involving US patent 12,186,474, the key takeaway is that the patent's validity has never been substantively tested before the PTAB.

• No Claims Invalidated: Be aware that the patent owner can rightfully assert all claims, as none have been canceled or invalidated.
• PTAB Challenge is a Viable Option: The time-barred denial of the previous PGR means the door is wide open for a new inter partes review. A defendant should immediately consider commissioning a prior art search to evaluate the strength of a potential IPR petition. The petition filed in PGR2025-00077, which is publicly available in the USPTO's Patent Center system, could serve as a useful, though not definitive, starting point for this analysis.
• Absence of Merits Decision: The fact that no proceedings are active and the only historical one was procedurally dismissed is a critical data point. While many asserted patents attract PTAB challenges, this one's history is clean. This does not imply strength, but merely a lack of a successful challenge to date. A new IPR would be the first time the PTAB addresses the patent's merits.