Sunlighten LLC v. Peak Wellness USA LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Sunlighten, LLC (Missouri)
  • Defendant: Peak Wellness USA LLC (Wyoming)
  • Plaintiff's Counsel: Avek IP, LLC; LAW OFFICE OF TOM WAGSTAFF JR.
• Case Identification: 1:26-cv-7782, N.D. Ill., 07/02/2026
• Venue Allegations: Venue is asserted based on the defendant's principal place of business being located in Chicago, Illinois, within the district, as well as alleged acts of infringement occurring in the district.
• Core Dispute: Plaintiff alleges that Defendant's line of infrared saunas infringes a patent related to dynamic control systems for multiple, distinct infrared heating elements within a sauna.
• Technical Context: The technology concerns advanced infrared saunas that use multiple, independently controllable emitters to deliver different wavelengths of infrared radiation (e.g., near-, mid-, and far-infrared) for customized therapeutic experiences.
• Key Procedural History: The complaint alleges that Plaintiff put Defendant on notice of the patent and its infringement contentions via a letter dated November 26, 2025. Following this notice, Plaintiff alleges it obtained and inspected one of the accused saunas in May 2026, which confirmed its infringement allegations.

Case Timeline

Date	Event
2008-03-19	'787 Patent Priority Date
January 2019	Defendant Peak Wellness USA LLC was formed
2022-08-23	'787 Patent Issue Date
Before 2025-11-26	Defendant allegedly began offering the Infringing Saunas for sale
2025-11-26	Plaintiff sent notice letter to Defendant regarding the '787 Patent
March 2026	Plaintiff's attempt to purchase an accused "Rainier" sauna was canceled by Defendant
May 2026	Plaintiff obtained and inspected an accused "Shasta" sauna
2026-07-02	Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

• Patent Identification: U.S. Patent No. 11,419,787, "Dynamic Sauna," issued August 23, 2022 (the "'787 Patent").

The Invention Explained

• Problem Addressed: The patent describes a technical landscape where sauna heating elements were typically either traditional (e.g., hot rocks, steam) or basic infrared (IR), lacking the ability to provide granular, user-directed control over different IR wavelengths for targeted therapeutic purposes ʻ787 Patent, col. 1:52-61
• The Patented Solution: The invention is a system for a "dynamic sauna" that incorporates multiple, distinct types of IR emitters (e.g., near-infrared, mid-infrared, far-infrared) which can be independently controlled. This allows a user to select and combine different IR wavelengths, power levels, and target locations on the body, creating a customizable therapeutic session rather than a uniform heating experience ʻ787 Patent, abstract ʻ787 Patent, col. 2:23-39 Figure 9, for example, illustrates an embodiment with planar far-IR elements, ceramic mid-IR elements, and near-IR LEDs combined in a single emitter unit ʻ787 Patent, Fig. 9
• Technical Importance: This technology enabled a shift from static, single-mode saunas to dynamic, multi-spectrum IR environments, allowing for personalized treatments tailored to specific wellness goals like detoxification or pain management ʻ787 Patent, col. 5:1-5

Key Claims at a Glance

• The complaint alleges infringement of at least independent claims 13 and 19.
• Independent Claim 13:
  • An infrared-therapy device comprising:
  • an enclosure assembly for accommodating a user;
  • an infrared emitter coupled with the enclosure, where the emitter includes a first heating element (for near-IR) and a second heating element (for far-IR) that are "integrated into a single unit"; and
  • a control panel allowing a user to cause emission of near- and far-infrared radiation from the emitter.
• Independent Claim 19:
  • An infrared-therapy device comprising:
  • an enclosure assembly for accommodating a user;
  • a first heating element (for near-IR) positioned to emit toward a user's torso;
  • a second heating element (for far-IR) also positioned to emit toward the user's torso "from substantially the same vertical position" as the first; and
  • a control panel allowing a user to cause emission of near- and far-infrared radiation from these elements.

III. The Accused Instrumentality

Product Identification

The accused products are a line of saunas sold by Defendant under the names "Aspen," "Olympus," "Rainier," "Shasta," "Fuji," "Everest," "Patagonia," "Crown," "Matterhorn," "Denali," "El Capitan," and "Kilimanjaro" (collectively, the "Infringing Saunas") Compl. ¶16

Functionality and Market Context

The complaint alleges that the Infringing Saunas incorporate "infrared heating systems, control features, and other relevant technical characteristics" that infringe the '787 Patent Compl. ¶22 The allegations are based on a review of Defendant's product specifications, marketing materials, and user manuals, and were purportedly confirmed by a physical inspection of a "Shasta" model sauna Compl. ¶22 The complaint frames Defendant as an imitator seeking to capitalize on Plaintiff's innovation and market success Compl. ¶13 No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint references claim charts in "Exhibit B" which were not attached to the public filing. The following tables summarize the infringement theory as can be inferred from the complaint's narrative allegations, which assert that an inspection of the "Shasta" sauna confirmed the presence of the infringing features Compl. ¶¶21-22

'787 Patent Infringement Allegations (Claim 13)

Claim Element (from Independent Claim 13)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
an enclosure assembly for accommodating a user	The accused products are saunas, which are enclosures for users.	¶16	col. 22:2-3
an infrared emitter coupled with the enclosure, the emitter including a first heating element operable to emit near-infrared radiation and a second heating element operable to emit far-infrared radiation, the first and second heating elements being integrated into a single unit	The accused saunas allegedly contain infringing "infrared heating systems" which, based on the claim, are alleged to be integrated units containing both near-IR and far-IR emitting elements.	¶22	col. 22:4-10
a control panel associated with the enclosure and operably coupled with the first heating element and the second heating element, the control panel operable by the user to cause near-infrared and far-infrared radiation to be emitted	The accused saunas allegedly possess "control features" that allow users to operate the infringing heating systems, thereby causing the emission of near- and far-infrared radiation.	¶22	col. 22:11-18

'787 Patent Infringement Allegations (Claim 19)

Claim Element (from Independent Claim 19)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
an enclosure assembly for accommodating a user	The accused products are saunas, which are enclosures for users.	¶16	col. 22:32-33
a first heating element operable to emit near-infrared radiation and positioned within the enclosure to emit the near-infrared radiation toward a torso of a human user positioned within the enclosure	The accused saunas allegedly contain infringing "infrared heating systems," which are alleged to include a near-IR emitter positioned to radiate toward a user's torso.	¶22	col. 22:34-37
a second heating element operable to emit far-infrared radiation and positioned within the enclosure to emit the far-infrared radiation toward the torso of the human user positioned within the enclosure, the first heating element and the second heating element emitting the near- and far-infrared radiation toward the torso from substantially the same vertical position within the enclosure	The accused saunas allegedly contain infringing "infrared heating systems," which are alleged to include a far-IR emitter positioned at substantially the same vertical level as the near-IR emitter, both radiating toward the user's torso.	¶22	col. 22:38-48
a control panel...operable by the user to cause near-infrared and far-infrared radiation to be emitted	The accused saunas allegedly possess "control features" that allow users to operate the infringing heating systems.	¶22	col. 22:49-56

• Identified Points of Contention:
  • Scope Questions: A primary issue for Claim 13 will be the interpretation of "integrated into a single unit." The court will need to determine if the accused products' heating elements meet this structural limitation as defined by the patent, or if they are merely separate components co-located within the sauna.
  • Technical Questions: A key factual question for Claim 19 will be whether the accused saunas' near- and far-infrared emitters are in fact positioned to emit "from substantially the same vertical position." This raises a question of both claim construction (what does "substantially" mean in this context?) and evidentiary proof regarding the specific physical layout of the accused products.

V. Key Claim Terms for Construction

• The Term: "integrated into a single unit" (Claim 13)

• Context and Importance: This term is critical to determining infringement of Claim 13. If Defendant's near- and far-IR emitters are constructed as physically separate components merely placed within the same sauna, they may not meet this limitation. Practitioners may focus on this term because it distinguishes a simple collection of parts from a purposefully combined apparatus.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The patent states that combinations of heating elements are "referred to generally as IR emitters" ʻ787 Patent, col. 5:56-59, which could suggest that any functional grouping might be considered an "emitter."
  • Evidence for a Narrower Interpretation: The specification explicitly provides an example for this term: "IR emitters may comprise such combinations that are integrated into a single unit, like for example, that shown in FIG. 9" ʻ787 Patent, col. 5:59-62 Figure 9 depicts a complex, layered assembly of different heater types. This specific example may be used to argue for a narrower definition requiring a high degree of physical and functional integration.

• The Term: "from substantially the same vertical position" (Claim 19)

• Context and Importance: This spatial limitation is a core element of Claim 19. The infringement analysis will hinge on how closely the vertical alignment of the accused emitters must be to satisfy this term.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The patent does not provide an explicit numerical definition for "substantially," which may support an argument that emitters located on the same general wall panel, aimed at the same body region, meet the requirement.
  • Evidence for a Narrower Interpretation: The use of the term "position" could be argued to imply a specific, narrow location. A defendant may argue that if the geometric centers of the emitters are vertically separated by more than a trivial distance, they do not occupy "substantially the same" position. The figures show various emitter placements but do not provide specific guidance on this term, making it a likely point of contention.

VI. Other Allegations

• Indirect Infringement: The complaint pleads only direct infringement under 35 U.S.C. § 271(a) Compl. ¶27 It does not contain allegations to support claims for induced or contributory infringement.
• Willful Infringement: The complaint alleges willful infringement, asserting that Defendant had "actual knowledge" of the '787 Patent and its alleged infringement at least as of November 26, 2025, the date of Plaintiff's notice letter Compl. ¶31 The complaint alleges that Defendant's continued infringement after receiving this notice has been deliberate and willful, and it seeks treble damages as a result Compl. ¶31 Compl. ¶32

VII. Analyst's Conclusion: Key Questions for the Case

1. A core issue will be one of definitional scope: can the term "integrated into a single unit," which the patent exemplifies with a complex, multi-layer apparatus, be construed to read on the potentially simpler assembly of heating elements in the accused saunas? The outcome of this claim construction battle may be determinative for Claim 13.
2. A second key question will be one of spatial arrangement and proof: does the physical layout of the accused saunas meet the limitation of emitting radiation "from substantially the same vertical position" as required by Claim 19? This will involve both a legal construction of the term "substantially" and a factual, evidence-based comparison of the accused products against that construction.
3. Finally, a central question for damages will be willfulness: did the Plaintiff's November 2025 letter provide sufficient notice to make Defendant's subsequent alleged infringement "willful" under the standards set by patent law, potentially exposing Defendant to enhanced damages?