In-depth Analysis of FAR UV IP Case regarding Patent 11,246,951 B

Ramifications of the PTAB Preliminary Ruling on Far-UV Sterilray Patent Claims


The case IPR2023-00695 revolves around Patent 11,246,951 B2 (referred to as the ’951 patent). The patent’s veracity is being challenged by the petitioner on the basis of prior art references, namely Eckhardt and Sosnin. This review specifically addresses the examiner’s previous decisions and whether there was any material error in their assessment.


  1. Connection to Eckhardt: The Patent 11,246,951 B2 is believed to have the same application as Eckhardt. Both Eckhardt and the Eckhardt Patent reportedly have similar disclosures.
  2. Role of Sosnin: The discussion delves into a publication from Sosnin, which describes a 222 nm excimer lamp, a critical component the petitioners focus on. The patent owner argued that the examiner considered the publication from Sosnin, while the petitioner emphasized that the examiner did not consider the Sosnin references.
  3. Referencing Errors: It is highlighted that there’s an error in referencing Ex. 1038 as it doesn’t contain the mentioned pages.
  4. Comparison of Sosnin and Sosnin IEEE: The Sosnin IEEE publication is regarded to have similar disclosures as the main Sosnin reference. Both discuss the use of UV irradiance for sterilization, specifically using excilamps. The wavelength between 240 and 300 nm, particularly at 222 nm, is underlined for its ability to disinfect.
  5. Examiner’s Oversight: The petitioner points out that the examiner might have overlooked key teachings of Eckhardt, especially when it comes to the use of UV light sources and ranges for disinfection.
  6. Patent Owner’s Defense: The patent owner believes the examiner acknowledged Eckhardt and other references. The examiner’s statement, which highlights the uniqueness of the patent, emphasizes its use of 222 nm UV radiation for the destruction of microorganisms.
  7. Eckhardt’s Role: The petitioner’s core argument revolves around the belief that the examiner, while using Eckhardt as an obviousness rejection, didn’t fully consider its teachings, especially the use of UV light.
  8. Conclusion on Material Error: After assessing both the Eckhardt and Sosnin references, it is believed that there was a material error in the previous considerations. The examiner’s conclusions, based on the presented evidence, were seen as an oversight.
  9. Institution Decision: Due to the presented arguments, there’s a decision to not exercise discretion to deny the institution under § 325(d). The institution of the inter partes review of all challenged claims of the ’951 patent is approved, and the trial will move forward based on the fully developed record.


This review highlights the critical role of prior art in patent cases and the importance of thorough evaluations. Errors or oversights during patent evaluations can lead to re-evaluations and legal disputes. In this case, the alleged oversight by the examiner regarding the teachings of Eckhardt and Sosnin is leading to a renewed review of the patent’s veracity.

Overall, the case showcases the complexities and nuances involved in patent evaluations and the rigorous scrutiny required to ensure that patents granted are indeed novel and non-obvious. The final outcome of the trial will determine the validity of Patent 11,246,951 B2.


The patent Owner does not propose a level of ordinary skill in the art. Prelim. Resp.

For purposes of this decision, we adopt Petitioner’s definition of a person of ordinary skill in the art, which seems reasonable given the technical nature of the ‘951 patent and is unopposed by Patent Owner at this stage. Accordingly, we determine that a person of ordinary skill in the art at the relevant time would have had at least a bachelor’s degree in an engineering discipline or in physics or a similar subject matter and would have had two to three years of work or research experience with UV disinfection technology and/or systems and would be familiar with the fundamentals of UV excimer lamps. We also note that less education could be compensated by more experience and vice versa.

C. Overview of Eckhardt and Sosnin

  1. Eckhardt

Eckhardt discloses a system and method for disinfecting air in an occupied space using germicidal ultraviolet light. Ex. 1004, Abstract. The document states that UV germicidal irradiation is known to be effective in disinfecting air, surfaces, and water by destroying or deactivating microorganisms such as bacteria, viruses, and molds. Id. at ¶ 5. Eckhardt describes that germicidal UV light generally has a wavelength of between about 200 nm and about 280 nm, with the most effective wavelength being about 254 nm. Id. at ¶ 6.

Eckhardt also describes a need for continuous disinfection of air in occupied spaces, especially in health care facilities, to reduce the risk of transmission of airborne infectious diseases. Id. at ¶ 7. The document suggests that the use of germicidal UV light for air disinfection in occupied spaces has been limited due to concerns about direct exposure to UV light, which can cause skin burns and eye injuries. Id. at ¶ 8.

  1. Sosnin

Sosnin discloses new bactericidal UV light sources known as “excilamps” and their applications. Ex. 1005. Sosnin describes that these excilamps have spectral lines in the VUV and UV ranges and can be used for various purposes, including microbial disinfection of air, water, and surfaces. Id. at 1. The document also discusses the efficiency of bactericidal action of UV light at different wavelengths and highlights that the most efficient bactericidal action is achieved at wavelengths of 207 nm and 222 nm. Id. at 2.

D. Alleged Obviousness Over Eckhardt and Sosnin

Petitioner contends that the subject matter of claims 1–5 and 7–18 of the ‘951 patent would have been obvious over the combined teachings of Eckhardt and Sosnin. Pet. 20-45.

  1. Claim 1

For claim 1, Petitioner argues that Eckhardt teaches a process for destroying DNA or RNA of microorganisms on a surface using UV light with a wavelength of about 254 nm, which is within the range of germicidal UV light. Pet. 21 (citing Ex. 1004, ¶¶ 5-6). Although Eckhardt does not disclose a specific wavelength of 222 nm, Petitioner contends that Sosnin teaches that the most efficient bactericidal action is achieved at wavelengths of 207 nm and 222 nm. Id. (citing Ex. 1005, 2). Combining these teachings, Petitioner asserts that it would have been obvious to a person of ordinary skill in the art to use a wavelength of 222 nm as taught by Sosnin in the process of Eckhardt to achieve better bactericidal action. Id. at 22.

Petitioner further argues that Eckhardt’s teachings about concerns of UV light exposure would lead a person of ordinary skill in the art to consider other wavelengths, such as 222 nm, that might provide effective germicidal action without causing harm to human or animal tissue. Id. at 23 (citing Ex. 1004, ¶ 8).

In summary, Petitioner contends that a combination of Eckhardt’s teachings about UV germicidal irradiation and Sosnin’s teachings about the bactericidal efficiency of 222 nm UV light would have rendered the claimed process obvious. Id. at 24.

  1. Dependent Claims

Petitioner provides detailed explanations for each of the dependent claims, asserting that their subject matter would also have been obvious based on the combined teachings of Eckhardt and Sosnin, in view of the level of ordinary skill in the art. Pet. 25-45.

E. Patent Owner’s Preliminary Response

In response, Patent Owner argues that the Petitioner has failed to establish a reasonable likelihood of prevailing on its challenge to the claims of the ‘951 patent. Prelim. Resp. 1-15. Specifically, Patent Owner contends that the cited references do not disclose or suggest all the limitations of the challenged claims. Id. at 3-10. Additionally, Patent Owner challenges Petitioner’s assertion that it would have been obvious to combine the teachings of the cited references and contends that Petitioner has failed to provide a sufficient rationale for the combination. Id. at 10-15.

III. Conclusion

Based on our review of the Petition, the Preliminary Response, and the evidence of record, we determine that Petitioner has established a reasonable likelihood that it would prevail in showing the unpatentability of at least one claim challenged in the Petition. Accordingly, we institute an inter partes review of all claims and all grounds asserted in the Petition.

It is ORDERED that inter partes review is instituted on all challenged claims and all asserted grounds.

Leave a Reply

Your email address will not be published. Required fields are marked *