US 8989860

I'll search for this specific patent number across the requested sources.

Let me run a couple more targeted checks for any litigation/PTAB activity and the related family member.

US Patent 8,989,860 — Analyst Summary

Search coverage and confidence note

I was able to confirm bibliographic and claim data for US 8,989,860 B2 from the authoritative patent record and cross-check it against FreePatentsOnline. However, I found no CAFC 2026 docket entry, no district-court litigation, and no PTAB proceeding naming this specific patent. Targeted searches returned only unrelated matters (e.g., Contour IP Holding LLC v. GoPro, Inc., Fed. Cir. No. 2026-2012) and non-patent coincidences (a GMC parts catalog "8989860 lamp assy."). Because a null litigation result can also mean the suit is simply not indexed in the sources I reached, I flag this as uncertain rather than a definitive "no litigation exists." No results contradicted the patent text below.

Bibliographic data

Abstract

High-frequency cardiac arrhythmias and fibrillations are terminated using electric-field pacing pulses with roughly an order of magnitude less energy than conventional cardioversion/defibrillation. Pulse frequency and number are selected based on a frequency analysis of the ongoing arrhythmia. Pulse energy is selected from 1/400 to ½ of conventional defibrillation energy, and electric-field amplitude is chosen to activate a multitude of effective pacing sites in heart tissue per pacing electrode. The number and locations of effective pacing sites are regulated by pulse amplitude and by the orientation of the electric field.

Plain-language overview of the independent claims

Claim 1 — Multisite electric-field pacing method (method-of-termination, frequency-gated).

1. Determine whether the high-frequency arrhythmia/fibrillation has a rate higher than that permitting ATP (i.e., ATP ineligible). Only if so, proceed:
2. Determine a real-time Fourier spectrum of the arrhythmia;
3. Select several highest frequencies f_i from that spectrum;
4. Select pacing pulse energy ~0.01–1 J;
5. Select pacing parameters — number of pulses N and pacing frequency F — based on those f_i values;
6. Deliver the pulses to the heart to terminate the arrhythmia.
   Core concept: let the arrhythmia's own frequency content dictate the pacing prescription, and use low-energy field pulses rather than a defibrillating shock.

Claim 6 — Anti-fibrillation pacing (AFP) method (more specific variant).
Same ATP-eligibility gate and Fourier-spectrum step, then:

• Select pulse frequency based on the several highest f_i;
• Select pulse energy ~0.01–1 J;
• Select electric-field amplitude ~0.15–0.5 V/cm, sized to activate a multitude of naturally existing heterogeneities in the heart as effective pacing sites per pulse;
• Deliver 4 to 8 pulses at the selected frequency, energy and amplitude.
  Core concept: the amplitude that recruits natural tissue heterogeneities ("virtual electrodes") is the lever that sets how many pacing sites fire from a single electrode.

Dependent claims 2–5 add: F differing by ≥~5% from any determined highest frequency (claim 2); N = max over i of pulses needed to scan each rotating wave's phase space and hit its vulnerable window (claim 3); n = 3 wave sources (claim 4); and choosing F to minimize N or keep 2 ≤ N ≤ 10 (claim 5).

Practical takeaways

• The patent's central novelty is electrode-count decoupling: multisite pacing is achieved from a single lead by tuning field amplitude (site count) and field orientation (site position), rather than by implanting one lead per site.
• Claim 1 is gated on an ATP-ineligibility determination — a diagnostic precondition, not merely a pacing step.
• The specification reports measured termination energies of 0.15 J (AF, in vivo), 0.08 J (AF, in vitro) and 0.14 J (VF, in vitro) versus a conventional defibrillation field of ~6 V/cm, and states the field should not exceed 6 V/cm.
• Family members to watch (possibly relevant to any future docket): US 9,855,439 B2, plus later Max Planck filings EP 3342455 B1 and EP 4268885 A1.

I'll search for litigation involving US patent 8989860.

Let me search litigation-specific databases.

Let me search more targeted litigation databases.

Litigation Search Results: US Patent 8989860

Bottom line: I found no evidence of any litigation involving US 8989860.

I performed targeted searches across the general web and patent-focused resources (including results pointing to the Unified Patents litigation portal area, PTAB filings, FreePatentsOnline, and PatentLeaderboard). None of the results identified any district court case, Court of Appeals for the Federal Circuit appeal, or PTAB proceeding asserting or challenging US 8989860.

What the search turned up instead

• Patent bibliographic data only — FreePatentsOnline and Google Patents entries confirm US 8989860 B2 ("Multisite heart pacing with adjustable number of pacing sites for terminating high frequency cardiac arrhythmias"), assigned to Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V., inventors Stefan Luther, Valentin Krinski, and Eberhard Bodenschatz. This is consistent with the authoritative full text you provided.

• No case records — No docket entries, complaints, consent judgments, or appeal records naming US 8989860 were retrieved. The "8989860" matches that did appear in searches were unrelated entirely (e.g., a Brazilian corporate-registration PDF and a GMC automotive parts catalog referencing a lamp assembly part number).

• Related activity, but not litigation of this patent — The full patent text shows this patent is part of a family that cites several patents (Sweeney, Kroll, etc.) and itself is cited by later Max-Planck filings (e.g., EP3342455B1, EP4268885A1). These are citations and family members, not litigation.

Important caveats

1. Search completeness. I was unable to exhaustively query every litigation-specific database (Unified Patents litigation caselist, PACER direct, CourtListener, Docket Alarm) within the available search steps. Some results returned were PTAB/IPR documents about other patents and Unified Patents' general "RPX/real-party-in-interest" appeals — none involved US 8989860.

2. No fabricated results. Per the strict rule, I have not auto-corrected any identifiers or substituted a similar number. I am reporting only what was actually found, and explicitly stating that I did not find litigation.

3. A negative is not proof of a legal conclusion. The absence of search hits does not guarantee no litigation exists — for example, a suit could be filed under a proprietary docket not surfaced, or pleadings could reference the patent only by its related application (US 12/040,007 / US 20090062877A1) or by the continuation-in-part lineage.

Recommendation if you need a definitive answer

To confirm conclusively, run direct queries against:

• Unified Patents litigation portal: https://portal.unifiedpatents.com/litigation/caselist (filter by patent number 8989860)
• CourtListener / RECAP: https://www.courtlistener.com (search "8989860")
• PACER (party search: "Max-Planck-Gesellschaft")
• USPTO Patent Center / Assignment for any recorded licenses or assignments tied to enforcement

If no litigation exists (as my searches indicate), the correct answer to your query is: no known litigation involving US 8989860. I am not able to provide plaintiff, defendant, jurisdiction, case number, filing date, or outcome because no such case was identified.

I'll verify the structured "no PTAB proceedings" finding against live sources before writing this up.

Let me run a couple more targeted checks before finalizing.

PTAB / AIA Trial Proceedings — US 8,989,860

Proceedings overview

Total AIA trial proceedings on file for US 8,989,860: zero (0). The canonical structured source (USPTO Open Data Portal "PTAB proceedings on file" block) returns no IPRs, PGRs, or CBMs for this patent, and my independent web checks surfaced no petition, institution decision, FWD, or appeal naming the patent — so there is no "claims invalidated / sustained / denied / settled" breakdown to report, because there is nothing to break down. Bottom line for a defendant: the patent has never been tested at the Board. It is neither "hardened by survival" nor "narrowed by cancellation" — it is un-challenged, which means every claim (1–6) stands as issued, and the invalidity record you would need to attack it has to be built from scratch.

Caveat / do-not-conflate flag. My searches turned up two different patents whose numbers are easy to confuse with 8,989,860, and neither is this patent:

• US 8,898,260 (Singh et al.) — subject of ex parte reexamination control 90/019,489 (requested 2024-04-17, granted; requester was Unified Patents). That is an ex parte reexam of a different patent, not an AIA trial, and not US 8,989,860. Source: Docket Alarm – reexam transmittal, 90/019,489.
• A docket-alarm hit for "8898260" (digit-transposed) likewise is not this patent.
  Per the operating rules I have not auto-corrected or merged any of these identifiers; I am explicitly reporting that they are not proceedings on US 8,989,860.

Per-proceeding detail

None. There are no proceeding numbers to list (IPR20xx-xxxxx, PGR20xx-xxxxx, CBM20xx-xxxxx) for US 8,989,860. I will not invent one. Consequently there are also no judge panels, no institution decisions, no FWDs, no settlement terminations, and no Federal Circuit appeals to report for this patent.

Strategic summary

Claim status of 8,989,860. All six issued claims are UNTESTED and SUSTAINED as-issued — none canceled, none narrowed, none adjudicated. The patent has 6 claims: independent claim 1 (method of terminating high-frequency arrhythmias by multisite electric-field pacing, with a Fourier-spectrum step and a 0.01–1 J pulse-energy selection), dependent claims 2–5 (pacing frequency ≥ ~5% off the detected peaks; N = max(N_i); n = 3; F chosen to keep 2 ≤ N ≤ 10), and independent claim 6 (AFP method with a 0.15–0.5 V/cm amplitude limitation activating natural heterogeneities, delivering 4–8 pulses). Because no tribunal has construed or invalidated any of these terms, claim construction is greenfield — nothing is frozen by a PTAB record, and nothing is estopped.

Estoppel landscape. There is no § 315(e)(2) estoppel in play against any party, because no IPR/PGR was ever instituted. That cuts both ways for a defendant: you have no prior petitioner's win to lean on, but you also face no General Plastic / § 315(e) prior-petitioner baggage and no time-bar inherited from anyone. A fresh petitioner today is free to raise § 102/§ 103 grounds based on patents and printed publications. Note the patent's own prosecution record supplies ready-made art hooks — Sweeney US 4,996,984 / US 7,418,293, Kroll US 7,006,867 / US 7,809,439, and the non-patent literature (Allessie 1991; Pumir & Krinsky 1999; Takagi 2004; Sepulveda/Roth/Wikswo 1989) — some of which the applicant distinguished. Those same references are the natural starting point for an IPR, subject to § 325(d) discretion if the Examiner already considered them.

Pattern signals. No defensive aggregator (Unified Patents, RPX, etc.) appears anywhere in this patent's chain — the only Unified Patents hit in my search belongs to the unrelated 8,898,260 reexam. The patent owner (Max-Planck-Gesellschaft) has not been an aggressive PTAB appellant on this family; the family's downstream activity is prosecution, not litigation: continuation/divisional US 9,855,439 (div. of 13/399,229) and later Max-Planck filings EP 3342455B1 and EP 4268885A1. The prior "litigation summary" section also found no litigation involving this patent — consistent with a patent that has generated zero adversarial record in either forum.

Recommended next steps

1. State the negative plainly, and treat it as the operative finding. There is no PTAB activity on US 8,989,860. Per the task rule, "the absence is itself a signal." A medical-device patent from 2007/2012 that has drawn a decade-plus of product activity without a single IPR suggests either limited commercial assertion or a portfolio the owner has chosen to advance by prosecution (continuations, EPs) rather than enforcement. If you received a demand letter invoking this patent, that letter is not backed by any adjudicated or Board-tested validity — and equally, you cannot cite any cancellation to rebut it.

2. If you are a defendant, you would be the first mover. A petition would need to be filed within the statutory window and would face no predecessor estoppel. Candidate art is visible in the face of the patent (Sweeney, Kroll, Allessie, Pumir/Krinsky, Takagi, Sepulveda). Weigh § 325(d) risk, since several of these were before the Examiner.

3. Watch the sibling and the reexam-named patents, but don't conflate them. Monitor US 9,855,439 (the direct divisional of this patent) for any separate challenge — a challenge there would not, by itself, invalidate 8,989,860, though overlapping claims may create a § 315(e) / issue-preclusion spillover worth tracking. And keep 90/019,489 (US 8,898,260) firmly separate.

4. Verify at the primary source before relying on this negative. I was unable to run exhaustive queries against the PTAB E2E system and USPTO Patent Center before hitting the step limit. Confirm directly at:

   • USPTO PTAB E2E: https://ptacts.uspto.gov/ptacts/ (search patent 8,989,860)
   • USPTO Patent Center / ODP for any AIA trial data tied to application 13/399,229
   • CourtListener (https://www.courtlistener.com) for any CAFC appeal referencing the patent

   If those confirm no proceedings, the correct and final answer is: no AIA trial proceedings exist on US 8,989,860; all claims 1–6 remain as issued and untested.

I'll rebuild the ownership chain for US 8,989,860 from the assignment data in the authoritative record and cross-check the parties.

Ownership Chain Reconstruction — US 8,989,860 B2

Source note / methodology. The Assignment Center could not be queried live within the available search steps. The reel/frame, execution-date, and recording-date data below are taken from the USPTO assignment records as reproduced in the authoritative Google Patents "Legal Events" table for US 8,989,860 (which mirrors Assignment Center data), cross-checked against the sibling patent US 9,855,439 B2. One field the task specifically asks for — correspondent of record — is not reproduced in that record, and I was unable to retrieve it. I flag that explicitly rather than inventing a name. Verify at: https://assignmentcenter.uspto.gov/ (legacy: https://assignment.uspto.gov/patent/index.html).

Inventors

Unusual patterns: None of the classic pre-fire-sale tells. Specifically:

• All three inventors assigned to a common employer/affiliate, not to three different entities.
• The two assignment documents were executed within 3 days of each other (2012-02-24 and 2012-02-27) and recorded together on 2012-03-20 — i.e., centralized, employer-driven execution shortly after the CIP filing, not an inventor-initiated departure transfer.
• No inventor departure / re-assignment appears anywhere downstream. There is no second-generation inventor assignment to a third party.
• Minor note: Krinski (the non-institutional, non-salaried collaborator) executed separately and three days earlier than the two MPIDS scientists, which is the fingerprint of MPI's standard practice of taking a standalone assignment from unaffiliated co-inventors.

Original assignee

Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. ("Max Planck Society"), Hofgartenstrasse 8, 80539 Munich, Germany.

• Type / line of business: A registered non-profit association (eingetragener Verein) that is the central legal and patent-holding entity for the ~80 Max Planck Institutes. Its business is publicly funded fundamental research; its IP is commercialized through its wholly-owned tech-transfer subsidiary Max-Planck-Innovation GmbH.
• Product embodying the claims: No. Max Planck is a research organization and does not manufacture or sell cardiac rhythm-management devices. The specification contemplates external and implantable AFP devices (FIGS. 5–7), but no product was brought to market by the assignee.
• Current status: Operating. Not acquired, not dissolved, not in bankruptcy. Financing is statutory (Bund/Länder), so insolvency risk is negligible.
• Signals of active ownership (not abandonment): maintenance fees paid 2018-09-13 (4th year) and 2022-09-14 (8th year), both recorded as small-entity payments — the statutory small-entity status is consistent with a non-profit research institution and confirms the patent remains live.

Assignment timeline

Two assignments appear in the record. Both are inventor → original assignee; no post-issuance assignment exists.

• 2012-02-24 (executed) / recorded 2012-03-20 — Reel 027891 / 0252

  • Conveyance: Assignment (Assignment of Assignors' Interest)
  • Assignor: Valentin Krinski, Dr. (sole assignor on this instrument)
  • Assignee: MAX-PLANCK-GESELLSCHAFT ZUR FOERDERUNG DER WISSENSCHAFTEN E.V.
  • Correspondent: Not retrievable from the sources available to me. Flag: the fact that this reel and the companion reel below sit in the same 027891 reel batch with a 33-frame gap and bear the same recording date indicates they were filed together — consistent with a single MPIDS/Max-Planck- Innovation recording agent — but I have no attorney name, so I make no recurrence finding.
  • Context: Inventor-to-employer assignment of rights in the patent family (routine, not a fire-sale or reorg).

• 2012-02-27 (executed) / recorded 2012-03-20 — Reel 027891 / 0285

  • Conveyance: Assignment (Assignment of Assignors' Interest)
  • Assignors: Stefan Luther, Dr.; Eberhard Bodenschatz, Dr.
  • Assignee: MAX-PLANCK-GESELLSCHAFT ZUR FOERDERUNG DER WISSENSCHAFTEN E.V.
  • Correspondent: Not retrievable (same caveat as above).
  • Context: Companion inventor-to-employer assignment; same recording batch, same day.

End of recorded chain. No further assignment appears — no LLC, no security agreement, no license record, no release, no correction, no change of name. The absence of any post-2012-03-20 record is itself the central finding: the original assignee still owns the patent.

Contradiction flag for the earlier section: the Google Patents legal-events table heads these entries "AS — Assignment / reassignment." The word "reassignment" there is a table label, not a factual second transfer. Both entries are first-instance inventor→assignee assignments; there is no prior assignee being divested.

Timeline diagram

timeline
    title Ownership of US 8989860
    2007 : Provisional filed by three inventors
    2008 : Parent application filed
    2012 : CIP application filed
         : Krinski assigns rights to Max Planck
         : Luther and Bodenschatz assign rights
    2015 : Patent issues to Max Planck
         : Divisional application filed
    2018 : Divisional issues as US 9855439
         : Maintenance fee paid 4th year
    2022 : Maintenance fee paid 8th year

NPE / troll-pattern signals

1. Shell-entity transfer — not present. The only assignee is a German non-profit research association (Hofgartenstrasse 8, Munich). No "IP / Holdings / Ventures" suffix, no registered-agent service address, no single-member LLC. Reels 027891/0252 and /0285.

2. Known asserter in the chain — not present. Neither assignor nor assignee matches Acacia, Marathon, IV, IPNav, Wi-LAN, Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, or any Unified Patents / RPX high-frequency-plaintiff list. Max Planck is a frequent patent filer and licensor, but it is not a PAE and has not been characterized as one.

3. Repeat correspondent across the chain — unclear. Signal cannot be evaluated: the correspondent of record is absent from the data I could reach. The two recordings share a reel batch (027891), consecutive frames region (0252 / 0285) and a single recording date (2012-03-20), which is consistent with one filing agent, but I will not state a name or a recurrence finding on that basis.

4. Cascading transfers — not present. Two assignments, both on the same day, both terminating at the same assignee. Zero chained LLCs, zero shared-registered-agent addresses.

5. Pre-litigation transfer — not present. Last assignment 2012-03-20; the prior analysis found no litigation naming this patent. Nothing upstream of a suit exists to arrange.

6. Bankruptcy fire-sale — not present. Max Planck is statutorily financed and not in insolvency; no Chapter 7/11 proceeding is associated with it. Nothing resembling Kodak/Nortel/Polaroid dynamics.

7. Privateering — not present. Max Planck retained ownership rather than transferring to an asserter, and it continues to prosecute the family in its own name (later family filings EP 3342455 B1 and EP 4268885 A1 are Max-Planck applications). Continued in-house prosecution is the inverse of privateering.

8. Defensive aggregator — not present. The chain does not terminate at RPX, AST, LOT, Unified, or OIN.

Verdict

Defensive / non-asserting — with a category caveat.

Justification: The entire recorded chain is two inventor→assignee instruments, both effective February 2012 and both recorded 2012-03-20 at reels 027891/0252 and 027891/0285, and it terminates at the original research-institution assignee, Max Planck Society, which still pays maintenance fees (4th year 2018-09-13; 8th year 2022-09-14, small entity) and continues prosecuting the family. None of the eight NPE signals is present (one, the correspondent-recurrence signal, is unclear for lack of the correspondent name), and the prior analysis identified no litigation naming US 8,989,860 — so there is no assertion to characterize as NPE conduct.

Caveat on the label: Max Planck is not a defensive aggregator like RPX or AST, so "Defensive / non-asserting" is used here in its operative sense — the patent is held by its original, non-asserting owner — not as a literal fit. If the taxonomy is applied strictly, the honest alternative is Insufficient data as to NPE status, because a non-practicing research institution that merely does not sue is not the phenomenon the NPE rubric is designed to flag, and no evidence supports labeling it one.

Verify: https://assignmentcenter.uspto.gov/ — search patent number 8989860 (or application 13/399,229); the two records above should return at reels 027891/0252 and 027891/0285.

I'll research the prior art references cited in US 8,989,860, focusing especially on the examiner-cited references most likely to bear on the claims.

Let me gather details on the remaining key references, especially the "virtual electrode" patent and the supraventricular tachyarrhythmia references.

I've reached my search budget, so I'll compile the prior-art analysis now from the authoritative patent record plus the reference details I retrieved. Note: I could not run a live USPTO Patent Center query directly, but the full citation list below is taken verbatim from the authoritative Google Patents record for US 8,989,860 (fetched 2026-09-28) that you supplied, and I retrieved substantive content for the most-pertinent references.

Prior Art Analysis — US 8,989,860 B2

Patent: Multisite heart pacing with adjustable number of pacing sites for terminating high frequency cardiac arrhythmias
Assignee: Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V.
App. No.: 13/399,229 · Filed 2012-02-17 · Issued 2015-03-24
Effective priority: 2007-03-03 (Prov. 60/892,855); CIP of US 12/040,007 filed 2008-02-29

Analytical framing (important)

Under 35 U.S.C. § 102, a single reference must disclose every element of a claim, arranged as in the claim, to anticipate it. My reading of the 25 cited references is that none appears to anticipate any of the six claims as a whole. The two independent claims (1 and 6) require a combination not found together in any cited reference:

1. an ATP-ineligibility gate, PLUS
2. a real-time Fourier spectrum with selection of several highest frequencies f_i, PLUS
3. pacing parameters N and F selected from those f_i, PLUS
4. low field-pulse energy (0.01–1 J), and (for claim 6) a field amplitude of 0.15–0.5 V/cm that recruits natural tissue heterogeneities as pacing sites.

Accordingly, most of these references are best characterized as § 103 obviousness art supporting individual limitations, with a subset serving as § 102 art against specific limitations (e.g., the low-energy limitation). I flag this explicitly rather than overstate anticipatory effect. The examiner-cited references (marked * in the record) cluster around spectrum analysis, multi-site pacing, low-energy fibrillation termination, and virtual electrodes — i.e., exactly the four pillars of the claims.

A. References with the strongest bearing on the claims

1. US 7,386,343 B1 — Spectrum-driven arrhythmia treatment method

• Assignee/inventors: Pacesetter, Inc.; Peter Boileau, Mark W. Kroll
• Filed/priority: 2005-09-30 (App. 11/240,950); granted 2008-06-10
• Description: An implantable cardioverter-defibrillator senses electrical signals, computes a frequency spectrum (Fast Fourier Transform) of each signal, computes a center frequency, and selects an electro-therapy (pre-programmed ATP, shock, or no therapy) based on that frequency. A companion application (US 20080200961 / US 7,809,439 B2) adds the "ATP sweet spot" and optimal therapy-location concepts.
• Relevance to claims: This is the closest cited reference to the spectral-selection concept of claim 1 / claim 6. It shares: real-time Fourier/spectral analysis of the arrhythmia and using the result to choose the delivered electro-therapy.
• § 102 assessment: Potential partial anticipation of claim 1's spectrum-determining step, but it does not disclose selecting "several highest frequencies f_i," nor selecting the number N and frequency F of pacing pulses from those peaks (it selects a therapy type, not a pulse train's N/F). It also lacks the ATP-ineligibility gate and the 0.15–0.5 V/cm heterogeneity-recruiting amplitude. Therefore more properly § 103 art when combined with a multi-site pacing reference.
• Contradiction to flag: The specification states "No prior art method known to the inventors uses Fourier spectrum to select parameters of pacing to terminate fibrillation." US 7,386,343 (and US 4,996,984 below) do use Fourier/spectral analysis to select therapy. This is a factual tension in the applicant's characterization that is worth noting for any validity analysis.

2. US 5,855,592 A — Systems and methods for multi-site cardiac defibrillation using multiple electrode structures

• Assignee/inventors: EP Technologies, Inc.; Whayne, Swanson, McGee
• Filed 1997-04-24; issued 1999-01-05 (priority 1997-04-23)
• Description: A spaced-apart, three-dimensional array of electrodes delivers multi-site pacing signals to entrain a large atrial area and defibrillate AF without a high-energy shock; the specification expressly contemplates a "low level defibrillation pulse of less than 1 Joule." It monitors electrical activity, generates an "organization-indicating output," and alters pulse characteristics in response.
• Relevance to claims: Directly addresses "multisite electric field pacing" and low-energy defibrillation (<1 J) — i.e., the energy range recited in claims 1 and 6.
• § 102 assessment: Potential anticipation of the "multi-site" + "low-energy" concepts underlying claim 6's preamble and energy limitation. However, it achieves multi-site pacing with many physical electrodes (one per site), not by recruiting natural heterogeneities from a single lead via field amplitude — the patent's stated point of novelty. And it does not teach Fourier-spectrum-driven N/F selection. Best treated as § 103 art against claim 6 in combination with a spectrum reference.

3. US 5,562,708 A — Method and apparatus for treatment of atrial fibrillation

• Assignee/inventors: Medtronic, Inc.; Combs, Duffin, Rao
• Filed 1994-04-21; issued 1996-10-08
• Description: A pacemaker delivers pacing-level pulses (≤0.05 J, and even ≤5 mJ in dependent claims) via large-surface-area electrodes to simultaneously stimulate multiple dispersed sites and thereby gradually entrain and terminate fibrillation. It expressly discusses the Allessie regional-capture work and "theoretical possibility of employing pacing level pulses (e.g. less than 0.05 joules) to terminate fibrillation."
• Relevance to claims: Bears directly on the pacing pulse energy selected from about 0.01 to about 1 J limitation in both independent claims (0.05 J falls squarely within 0.01–1 J), and on multi-site pacing.
• § 102 assessment: Strong § 102 challenge to the low-energy pacing limitation of claims 1 and 6. It does not, however, disclose Fourier-spectrum selection of N/F, the ATP gate, or field amplitude in V/cm recruiting natural heterogeneities. So it does not anticipate the claims as a whole, but it is the most dangerous single reference on the energy element.

4. US 4,996,984 A — Defibrillation method

• Assignee/inventor: Eli Lilly and Company; Robert J. Sweeney
• Filed 1989-09-26; issued 1991-03-05
• Description: Determines the mammal's fibrillation cycle length (obtained, e.g., by fast Fourier transformation) and administers two sequential current bursts timed at ~75% of the cycle length; each burst 4–10 A, 200–300 V, energy as low as ~3 J.
• Relevance to claims: Establishes the concept of using a Fourier-derived characteristic of the fibrillation to time the therapy — conceptually adjacent to claim 1's "determine a real-time Fourier spectrum … select … based on the frequencies."
• § 102 assessment: Not anticipatory. The pulses are high-voltage/high-current defibrillation bursts (200–300 V; ~3 J), outside the claimed 0.01–1 J pacing range, and there is no multi-site heterogeneity pacing or several-highest-frequency f_i selection. Reasonable § 103 art for the "frequency-analysis-guided timing" limitation.

5. US 7,142,928 B2 — Field stimulation about a discontinuity of the myocardium to capture the heart at reduced pacing thresholds

• Assignee/inventors: Medtronic, Inc.; Vinod Sharma, Xiaohong Zhou
• Filed 2002-12-03 (priority 2001-12-03); issued 2006-11-28
• Description: By forming a discontinuity (lesion/cleft) in cardiac tissue and pacing from a distance exceeding the tissue space constant, a stimulus below the normal capture threshold induces a transmembrane potential change near the discontinuity (a "virtual electrode" / virtual cathode–anode) that propagates — reducing pacing energy ~50%. The patent (and its cited Knisley "Virtual Electrode Effects in Myocardial Fibers" art) expressly invokes virtual-electrode theory at tissue heterogeneities.
• Relevance to claims: This is the reference the patent's own specification discusses at length (explicitly distinguished as creating a cut discontinuity). It is the closest art to claim 6's "activate a multitude of heterogeneities naturally existing in the heart as effective pacing sites."
• § 102 assessment: Not anticipatory for claim 6 because (i) it requires an artificially created discontinuity (blade cut), whereas claim 6 requires naturally existing heterogeneities; (ii) it is a single-site, sub-threshold capture technique, not multisite arrhythmia termination; and (iii) it lacks the Fourier/f_i selection. It is, however, high-value § 103 art on the virtual-electrode/heterogeneity mechanism, and the applicant's own specification concedes this mechanism was "well known in cardiology."

6. US 7,006,867 B1 — Methods and apparatus for overdrive pacing multiple atrial sites using an implantable cardiac stimulation device

• Assignee/inventor: Pacesetter, Inc.; Mark W. Kroll
• Filed 2002-07-09; issued 2006-02-28
• Description: Multiple atrial leads sense and pace at multiple sites at an overdrive rate; pulses may be staggered with a time delay (~12 ms) and may have different energy levels; for very high rates it falls back to an ATP burst of ~8–15 pulses at 10–20% above the detected rate. Explicitly "multiple site sensing and/or multiple site pacing."
• Relevance to claims: Bears on N (number of pulses) and F (pacing frequency relative to the arrhythmia rate) and on multi-site pacing. This is also the reference the patent's specification singles out, noting "Kroll … for pacing from, say, 5 sites he needs 5 leads."
• § 102 assessment: Not anticipatory. It does not disclose the Fourier/f_i selection, the ATP-ineligibility gate as a precondition to field pacing, the 0.15–0.5 V/cm amplitude, or heterogeneity recruitment. Fits § 103 as evidence that multi-site pacing with enumerated pulse counts and rate-based selection was known.

7. US 6,587,720 B2 and US 6,873,873 B2 — System/method for treating supraventricular tachyarrhythmias

• Assignee: Cardiac Pacemakers, Inc.
• Filed 1998-03-19; issued 2003-07-01 and 2005-03-29
• Description: Cardiac rhythm management that detects supraventricular tachyarrhythmias (including AF) and delivers tiered therapy (pacing/ATP then atrial shock), addressing shock timing.
• Relevance/§ 102: General background art on detecting and tiering therapy for atrial tachyarrhythmias. No anticipation — does not disclose spectral selection of N/F, natural-heterogeneity recruitment, or the specific low-energy field pacing. § 103 background only.

8. US 7,418,293 B2 and US 2006/0100670 A1 — Multiple pulse defibrillation for subcutaneous implantable cardiac devices

• Assignee/inventor: Cardiac Pacemakers, Inc.; Robert J. Sweeney
• Filed 2004-11-09; published 2006-05-11; US 7,418,293 issued 2008-08-26
• Description: Reduces required energy per pulse via multiple-pulse defibrillation; the patent states minimum energy per pulse ≈ one-quarter of single-pulse defibrillation energy.
• Relevance/§ 102: Relevant to the low-energy, multiple-pulse strategy of claims 1/6. Not anticipatory (shock energy, no spectral N/F selection, no field-amplitude/heterogeneity pacing). The specification itself compares against Sweeney's ~2.7–3 J minimum. § 103 art.

B. Remaining references — background / formality citations

These appear on the face of US 8,989,860 but, on the retrieved content, do not bear on the novel elements of claims 1–6 (they are cited as general field context, electrode/catheter structure, or detection conveniences):

None of these discloses all elements of any claim; their § 102 value is nil and their § 103 value is marginal/background only.

C. References cited but post-dating the 2007-03-03 priority — likely NOT § 102 prior art

These were cited in the record but their dates place them after the earliest claimed priority, so they may not qualify as prior art under § 102(b)/(e) unless an earlier-filed family member predates the relevant claim (relevant only for claim elements added in the 2012 CIP with a later effective date):

• US 2010/0042172 A1 — Armoundas, System and method for assessing atrial electrical stability — filed 2008-04-28, published 2010-02-18.
• US 2011/0009916 A1 — Igor Efimov, Method and device for three-stage atrial cardioversion therapy — filed 2007-12-11, published 2011-01-13.
• EP 2 177 243 A2 — Biotronik CRM, Method and apparatus for ectopic beat detection — filed 2008-10-16, published 2010-04-21.
• WO 2008/035070 A2 — Imperial Innovations, Atrial fibrillation analysis — filed 2006-09-20, published 2008-03-27.

Caveat: The WO 2008/035070 A2 date is close to the priority date (filed 2006-09-20, i.e., before 2007-03-03, but published 2008-03-27). I retrieved only partial metadata on it and could not confirm its substantive disclosure; given its title ("Atrial fibrillation analysis") it may be relevant § 102(e)/§ 102(a) art for the spectral-analysis limitation, and it should be verified directly against the subject matter of claim 1.

D. Non-patent literature cited (relevant to § 103, not § 102)

• Allessie M, et al., "Regional control of atrial fibrillation by rapid pacing in conscious dogs," Circulation 1991;84:1689–1697 — the foundational regional-capture art; explains why high-frequency AF cannot be entrained locally. Directly relevant to § 103 motivation.
• Pumir A, Krinsky V., "Unpinning of a rotating wave in cardiac muscle by an electric field," J. Theor. Biol. 199, 311–319 (1999) — the analytical model underlying FIG. 1 (obstacle-size vs. depolarization).
• Sepulveda NG, Roth BJ, Wikswo JP, "Current injection into a two-dimensional anisotropic bidomain," Biophys J 55(5):987–99 (1989) — origin of the "virtual electrode" concept.
• Takagi et al., "Unpinning and removal of a rotating wave in cardiac muscle," Phys. Rev. Lett. 2004, 93(5):058101 — unpinning of rotating waves.
• Daoud EG et al., Circulation 1996;94:1036–1040; Disertori M et al., Eur. Heart J. Suppl. 2001;3:16–24 — ATP clinical response data.

These are the scientific underpinnings the applicant relies on for patentability (the "unpinning/termination by scanning a rotating wave's phase space" mechanism), and they are more likely to be cited by an examiner or a challenger in a § 103 combination than as standalone § 102 art.

E. Bottom-line conclusions

1. No cited reference anticipates claims 1 or 6 in their entirety. No single reference discloses the claimed combination of (ATP-ineligibility gate) + (real-time Fourier spectrum → several highest f_i) + (N and F selected from f_i) + (0.01–1 J) + (natural-heterogeneity recruitment at 0.15–0.5 V/cm).
2. The most dangerous references are:
   • US 5,562,708 (Medtronic) — for the low-energy pacing limitation (≤0.05 J falls inside 0.01–1 J);
   • US 7,386,343 (Pacesetter) and US 4,996,984 (Sweeney) — for the Fourier/frequency-guided therapy selection;
   • US 5,855,592 (EP Technologies) — for multi-site, sub-1 J defibrillation/pacing;
   • US 7,142,928 (Medtronic) — for the virtual-electrode / heterogeneity mechanism (albeit requiring an artificial discontinuity).
3. A realistic invalidity theory would be a § 103 combination, e.g., US 5,855,592 or US 5,562,708 (multi-site low-energy pacing) + US 7,386,343 or US 4,996,984 (spectral selection of therapy/timing) + US 7,142,928 (virtual electrodes at tissue discontinuities). The applicant's key non-obviousness argument would rest on (a) using a single lead to create/control many pacing sites via field amplitude and orientation rather than many leads, and (b) naturally existing heterogeneities rather than a created discontinuity.

Explicit caveats

• I was unable to complete a direct USPTO Patent Center / PAIR retrieval for App. No. 13/399,229 within my search budget; the citation list above is taken from the authoritative Google Patents full-text record you provided. If you need the examiner's exact § 102/§ 103 rejections (as opposed to my independent assessment), that must be pulled from the file wrapper/Image File Wrapper.
• The § 102 "which claims" designations above are my analytical assessment of the references' disclosures, not representations of the examiner's actual rejections. Several of these references were likely cited only as general background or for formal (catheter/electrode) features.
• I did not fabricate any identifier; all patent numbers and dates are as listed in the record. Where I could not verify content (e.g., WO 2008/035070 A2), I say so rather than guess.

I'll verify the key prior-art references from the page's Prior Art section before building the § 103 analysis.

Let me verify one discrepancy I noticed between the specification's characterization of US 7,809,439 and the record.

Obviousness Analysis — US 8,989,860 B2 under 35 U.S.C. § 103

Reference date: Priority 2007-03-03 (provisional 60/892,855; CIP of US 12/040,007 filed 2008-02-29; this application filed 2012-02-17). Pre-AIA § 103 applies (filed before 2013-03-16).

Sources used: the Prior Art section of the US 8,989,860 Google Patents page (22–25 cited patent documents, 6 non-patent citations), plus verification of the four most load-bearing references against their own records. No reference in the page's list anticipates all elements of any claim; this is therefore a combination case under KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007).

1. Scope of the claims to be tested

Two structural observations matter for the analysis:

• Claim 1 is broad. It does not require the electric-field amplitude range, the "heterogeneity/virtual-electrode" mechanism, or the 4–8 pulse count. Claim 1 is essentially "spectrum-guided, low-energy, multi-pulse pacing for an ATP-refractory arrhythmia." The electrophysiology insight (claim 6) is not in claim 1.
• The specification concedes the governing physics. The applicant's own FIG. 1 is expressly derived from Pumir & Krinsky, J. Theor. Biol. 199, 311–319 (1999) ("the depicted data result from an analytical solution of a linearized (LR) model according to A. Pumir, V. Krinsky"), and the specification cites Sepulveda, Roth & Wikswo, Biophys. J. 55(5), 987–99 (1989) for the proposition that virtual electrodes "exist in all tissues." Both are listed in the page's Non-Patent Citations. Admissions in the specification about what the prior art taught are usable against the applicant.

2. Element-by-element mapping of the primary references

3. The three strongest § 103 combinations

Combination A — the "spectrum-guided low-energy unpinning" combination

US 7,386,343 B1 (=US 7,809,439 B2) + Takagi 2004 + Pumir & Krinsky 1999 + Sepulveda 1989, optionally + US 7,142,928 B2

This is the most damaging combination because it covers both independent claims without the "formed discontinuity" estoppel of US 7,142,928.

• US 7,386,343 B1 supplies every diagnostic step of claim 1: spectrum calculation, center-frequency/peak selection, and therapy selection driven by the spectral result. Its stated files show it as a Pacesetter patent (application 11/240,950 filed 2005-09-30; granted 2008-06-10; published as US 2008/0200961 A1). The application predates the 2007-03-03 priority date, so it is available as § 102(e)/§ 103 art. (US 2008/0200961)
• Takagi 2004 supplies the therapeutic mechanism and the quantitative bridge: field-based rotor unpinning at 0.52 V/cm with energy "2 orders of magnitude less than defibrillation energy." (PubMed 15323732; HAL hal-00015183)
• Pumir & Krinsky 1999 supplies the amplitude→depolarization relationship the applicant itself reproduces as FIG. 1, i.e., the teaching that raising field amplitude recruits progressively smaller heterogeneities.
• Sepulveda 1989 teaches that virtual electrodes are intrinsic to all tissue, supplying the "naturally existing" limitation of claim 6 without need for a created lesion.

Motivation to combine: both US 7,386,343 and Sweeney are directed to the same problem the patent states — reducing the energy of arrhythmia termination to avoid patient discomfort and tissue damage — and US 7,386,343 expressly ties therapy selection to the spectral content of the arrhythmia. Takagi 2004 supplies the "predictable" result (low-energy field termination of a rotor) and even identifies the target (the rotor/pinned wave) and the field magnitude. A PHOSITA reading Takagi 2004 and US 7,386,343 side by side would see a natural, two-step design: use the spectrum to pick the pacing interval, and use a low-amplitude field to hit the rotor.

Combination B — the "spectral multi-burst defibrillation" combination

US 4,996,984 (Sweeney) + US 7,386,343 B1 + US 7,006,867 B1 (Kroll) + US 5,855,592 A

• Sweeney supplies (i) FFT of the fibrillating heart, (ii) selection of number/timing/intensity of bursts from the measured cycle length, (iii) express motivation to reduce voltage/current/energy, and (iv) sub-3 J energies.
• Kroll supplies multi-site pacing with staggered pulse delivery.
• US 5,855,592 supplies multi-site defibrillation electrode structures.
• US 7,386,343 supplies the "spectrum is the control input" step.
• The KSR rationales engaged are (A) combining known elements (spectral analysis + multi-pulse low-energy delivery + multisite electrodes) to yield a predictable result, and (D) applying a known technique (spectrum-derived timing) to an analogous device (a multi-pulse pacing/stimulation generator) ready for improvement.

Combination C — for claim 6's amplitude window specifically

US 7,142,928 B2 + Takagi 2004 + Sepulveda 1989

US 7,142,928 is the single most on-point reference for the claim 6 concept: it teaches that pacing at an energy below the direct-capture threshold can still propagate a wavefront because of the transmembrane potential change induced at a discontinuity/heterogeneity. Its inventive step is forming the discontinuity (a cutting blade or fixation screw). The applicant's claim 6 removes that step and relies on naturally existing heterogeneities. Under KSR's "simple substitution of one known element for another," substituting natural heterogeneities for a deliberately formed lesion — with Sepulveda 1989 teaching that virtual electrodes exist naturally in all tissue — is a strong obviousness position. Takagi 2004 then supplies the claimed field magnitude (0.52 V/cm; note the claim says "about 0.15 to about 0.5 V/cm," and "about" is broad enough to reach 0.52).

4. Dependent claims

• Claim 2 (F ≥ ~5% from any f_i). Directly taught. Sweeney US 4,996,984 selects inter-burst timing as a percentage of the fibrillation cycle length — its own claims cover 30%–200%, 60%–85%, and 75%–85% of FCL; a 75–85% timing is a 15–25% offset from the cycle, comfortably ≥5%. The patent's own "Detailed Explanation of the Mechanism" concedes the rationale (pacing period must not sit close to T_i, or the required N becomes "unrealistically large"). (US 4,996,984)
• Claim 3 (N = max N_i to scan phase space and hit the VW). The VW concept and the "scan the phase space of a rotating wave" framing come from Pumir & Krinsky 1999 and Takagi 2004, both on the page. Caveat: the page's prior-art list does not contain a reference that expressly computes N as a maximum across n rotors. The closest is the Siemens Pacesetter WO 95/09029 reference found in searching ("scans symmetrically/centrifugally about the statistically significant starting value … The number and size of steps could be either programmable … or automatically computed by the pulse generator based upon the termination window size"), which is not in this patent's cited list; if it were added via an Information Disclosure Statement or IPR, claim 3 would be materially weaker. As the record stands, claim 3 is the least well-anticipated of the dependent claims.
• Claim 4 (n = 3). Highly vulnerable. The specification itself says "several (e.g., three)" and FIG. 8 simply depicts three spectral peaks; selecting the top three peaks is a routine optimization. US 7,386,343's multi-signal center-frequency ranking and WO 2008/035070 A2's DF analysis support it.
• Claim 5 (minimize N, or 2 ≤ N ≤ 10). Routine optimization under KSR ("a finite number of identified, predictable solutions"). Sweeney teaches selecting the number of bursts; the specification's own operable embodiment is 4–8.

5. Arguments the applicant can make against obviousness (and how strong they are)

a) Unexpected results (strongest defense). The specification reports measured termination energies of 0.15 J (AF in vivo), 0.08 J (AF in vitro) and 0.14 J (VF in vitro), versus Sweeney's stated minimum of 2.7–3 J — "~20 times less (obtained on n = 8 animals)" — and states that "[f]rom a conventional point of view, the method of the present invention should not be able to terminate AF or VF due to the very low energy." This is a Graham v. John Deere secondary-consideration argument of unexpected results. Its force depends on whether the ~20× reduction over Sweeney is truly unexpected in view of Takagi 2004's express teaching of a two-order-of-magnitude reduction. This is the crux of the case: if Takagi 2004 is treated as analogous art for the same purpose (terminating a cardiac rotor with a low-amplitude field), the "unexpected" energy reduction is the expected one, and the defense collapses. If a tribunal confines Takagi 2004 to "unpinning a pinned rotor in a preparation" and not to "terminating AF/VF in vivo," the defense has more room.

b) Teaching away / failure of others. Allessie 1991 (entrainment only "locally … several cm"), Daoud 1996 (only type I AF responds to atrial pacing) and Disertori 2001 (ATP registry results) can be argued as teaching away from pacing as a modality for high-frequency arrhythmias. But this argument cuts both ways: the documented failure of ATP is precisely the motivation a PHOSITA would have to pursue a different low-energy electrical modality. KSR requires that the prior art "criticize, discredit, or otherwise discourage" the claimed solution, not merely failing to achieve it. The stronger form of the argument is that these references teach away from pacing at a frequency near the arrhythmia frequency, which is why claim 2's ≥5% offset helps the applicant.

c) The single-lead, amplitude/phase-controlled multisite insight. The applicant's genuine advance is that multisite pacing is obtained without multiple leads by tuning amplitude (site count) and field orientation (site position). The specification's own comparison section asserts that Kroll "does not use or anticipate creation and control of several pacing sites with one lead only." This is a real, articulable distinction. Its weakness as an obviousness defense is that US 7,142,928 already taught field-based capture via induced transmembrane potential at a distance from the active electrode — i.e., the de-linking of pacing site from electrode location was known.

d) Claim 1's ATP-ineligibility gate. Because the specification fixes the ATP threshold at a frequency of about 4 Hz ("ATP … is only successful against low frequency arrhythmias (frequency not higher than 4 Hz)"), the gate is a known clinical determination. A functional preamble of this kind is unlikely, standing alone, to confer patentability; expect it to be construed narrowly and treated as a mental/clinical step.

6. Where the prima facie case is thin, and where it is strong

Strong obviousness positions:

1. Claim 1 over US 7,386,343 + Takagi 2004 (with Sepulveda 1989) — especially once the applicant's own admissions about Pumir & Krinsky 1999 (FIG. 1) and Sepulveda 1989 are put in evidence. Claim 1 requires no heterogeneity-formation step, no amplitude window and no particular pulse count; nearly all of its limitations are separately and expressly disclosed.
2. Claim 6's amplitude window over US 7,142,928 + Takagi 2004 + Sepulveda 1989. Takagi 2004's 0.52 V/cm and "2 orders of magnitude less than defibrillation energy" fall inside (or at the edge of) "about 0.15 to about 0.5 V/cm" and inside "0.01 to 1 J."
3. Claim 2 over Sweeney's percentage-of-FCL timing.
4. Claim 4 (n = 3) and claim 5 (2 ≤ N ≤ 10) as routine optimizations.
5. The 4–8 pulse count of claim 6 over Sweeney's multi-burst disclosures (two or three bursts) and US 7,418,293 / US 8,000,786 multi-pulse defibrillation — a numerical range with no disclosed criticality; absent evidence that the endpoints are critical, In re Aller / In re Woodruff reasoning applies.

Weaker positions (where the patent is most defensible):

1. Claim 3. No reference in the page's Prior Art section computes N as a maximum across the scanned phase spaces of n rotors. This is the one limitation that arguably reflects a specific algorithmic insight rather than routine design. (But see the WO 95/09029 note above — this could change.)
2. The specific algorithm in the Detailed Description (the dT, N_1/N_2/N_3 decision tree) is not claimed and therefore does not itself support patentability of the claim set as issued, but it evidences that the inventors made a non-trivial computational contribution that claim 3 partially captures.
3. In vivo AF/VF termination at 0.08–0.15 J is the best secondary-consideration evidence, if the applicant can show (i) the reference range was not suggested by the art and (ii) others had tried and failed to reach it with pacing.

7. Flags and discrepancies (per the strict-identifier rule)

1. US 7,809,439 B2 mischaracterized / mis-attributed in the specification. The specification states: "Kroll U.S. Pat. No. 7,809,439 B2 describes a conventional multisite pacing, i.e., for pacing from, say, 5 sites he needs 5 leads." The record does not support that characterization: US 7,809,439 B2 is the continuation (application 12/111,036, filed 2008-04-28) of US 7,386,343 B1 and is titled "Spectrum-driven arrhythmia treatment method" (Pacesetter, Inc.). Its own claims recite selecting a preferred electro-therapy location based on the maximum center frequency across sensed spectra. I flag this without auto-correcting either number. This matters for § 103: if the applicant intended to distinguish a Kroll multisite-pacing patent but actually described a spectrum-driven patent from the same field, the very reference the applicant tried to dismiss is one of the closest pieces of prior art to claim 1. Expect a validity challenger to use this specification statement as an admission that the applicant knew of and considered the spectrum-driven art.
2. No contradiction with the previously generated sections. The earlier bibliographic and litigation summaries are consistent with the authoritative text. Nothing in the prior-art record contradicts them; the litigation null result stands as an uncertain negative.
3. Date sensitivity (CIP priority). Because US 8,989,860 is a CIP of US 12/040,007 (filed 2008-02-29, published as US 20090062877A1 on 2009-03-05) with a 2007-03-03 priority claim, the effective date of each claim depends on whether the Fourier-spectrum pacing selection and the heterogeneity-amplitude limitation were supported in the earlier disclosure. If any claim is entitled only to the 2012-02-17 filing date:
   • US 7,386,343 B1 (granted 2008-06-10) becomes unambiguous § 102(b)/(e) art with no date argument;
   • US 20090062877A1 (the applicant's own parent publication, 2009-03-05) may itself be prior art against newly added subject matter.
     I cannot resolve the written-description question from the page alone and flag it as an open issue rather than a conclusion.

8. Bottom line

• No single reference on the page anticipates any claim. The case is a combination case.
• Claim 1 is, on this record, the most vulnerable: US 7,386,343 B1 supplies the entire spectrum-driven therapy-selection sequence; Sweeney US 4,996,984 supplies FFT-based arrhythmia characterization, number/timing-from-cycle-length selection, and the express energy-reduction motivation; Takagi 2004 and Pumir & Krinsky 1999 supply the low-amplitude field termination of the rotor; and Sepulveda 1989 supplies the natural "virtual electrode." Motivation is supplied by the shared objective of reducing defibrillation energy to avoid pain and tissue damage, and Takagi 2004 provides a reasonable expectation of success at the claimed field/energy level.
• Claim 6 is vulnerable over US 7,142,928 B2 + Takagi 2004 + Sepulveda 1989, with the only real gap being the substitution of natural heterogeneities for a formed discontinuity — a substitution the art itself suggests.
• Claim 3 is the strongest defensive ground, and claims 4 and 5 are the weakest, being routine optimizations of a small numerical design space.
• The decisive contest will be Takagi 2004's scope: whether it is treated as analogous art establishing an expected (not unexpected) ~100× energy reduction. The applicant's best counter is the measured in vivo/in vitro result of 0.08–0.15 J on n = 8 animals against Sweeney's 2.7–3 J, offered as an unexpected result. Moderate-to-high confidence in the element mappings above (they track express disclosures and the applicant's own admissions); low confidence as to how a tribunal would weigh the unexpected-results argument, which is a factual question I cannot resolve from the patent record alone.