Obviousness

Under 35 U.S.C. § 103, an invention is obvious if the differences between the claimed invention and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art (PHOSITA). The analysis requires identifying the scope and content of the prior art, ascertaining the differences between the prior art and the claims at issue, and resolving the level of ordinary skill in the pertinent art. The Supreme Court's decision in KSR International Co. v. Teleflex Inc. emphasized that obviousness can arise from common sense, design motivations, or other market forces.

US Patent 9700642 claims methods for destroying DNA or RNA of microorganisms on a substance or surface using specific ultraviolet (UV) wavelengths, particularly 222 nm and 282 nm (and optionally 207 nm or 254 nm), and specifically mentions human or animal skin as a substance or surface to be disinfected. The patent introduces a "new ultra-violet (NUV) source," which it describes as an excimer lamp capable of emitting narrow spectral bands at chosen wavelengths.

The patent's background section discusses several relevant pieces of prior art and technological context:

• Commercially available UV lamps: These are described as "mercury based and emit principally at 254 nm." They are known for destroying "virus, bacteria, spores and pathogens" (VSP) in room air, but "require a long time to be effective in treating large flowing volumes of air that pass quickly down large ducts. Its long treatment time is impractical for treating most surfaces."
• Magnetic based apparatus: Mentions Wesley, U.S. Pat. No. 4,458,153 (liquids in pipes) and Sangster, U.S. Pat. No. 5,750,072 (sterilizing fluid mist with magnetic field), both of which require time to deactivate VSPs.
• Hofmann, U.S. Pat. No. 4,524,079: Directed to treating foodstuffs, requiring pulsed radiation for "short action time," but limited by "power required to treat large areas and the apparatus design."
• Scientific Understanding of UV Absorption: The patent acknowledges that "DNA action spectra show that absorption increases as the wavelength decreases, with a relative maxima at 260 nm and largest at 200 nm." It further notes that "Most literature credits this peak [200 nm] to protein absorption" and that "the steep rise in absorption below 240 nm is exhibited by most proteins." Additionally, the patent states, "proteins also have an absorption maximum at about 280 nm due to the absorption by the aromatic amino acids phenylalanine, tyrosine and tryptophane."
• Excimer Lamps (NUV sources): The patent states, "During the past few years, new UV emitting lamps based on the excitation of excimers are becoming commercially available." These emitters "produce single line or narrow spectral emission at a wavelength determined by the gas composition of the lamp."

Based on these disclosures, the following combinations of prior art would render the claimed invention obvious:

Obviousness for Claim 1 (Disinfection of Human or Animal Skin using 222 nm or 282 nm)

Claim 1: A process for destroying a DNA or RNA of a microorganism on a substance or surface comprising the steps of: generating photons of at least one wavelength corresponding to a peak absorption wavelength of DNA or RNA, the at least one wavelength being at least one of 222 nm and 282 nm; directing the photons to the substance or surface to be disinfected, whereby the photons are selected to destroy a plurality of chemical bonds within the DNA or RNA of the microorganisms; and wherein the substance or surface to be disinfected is human or animal skin.

Combination of Prior Art References: General knowledge of UV disinfection (using mercury lamps, 254 nm) + Scientific understanding of UV absorption spectra (specifically protein absorption peaks at shorter wavelengths) + Availability of excimer lamps (NUV sources) + Motivation to improve efficiency and expand application.

Motivation for Combination:
A person having ordinary skill in the art (PHOSITA) would have been motivated to combine these elements for the following reasons:

1. Addressing Limitations of Existing UV Disinfection: The prior art explicitly describes 254 nm mercury lamps as requiring "long exposure times" which are "impractical for treating most surfaces." A PHOSITA would recognize the need for faster, more effective disinfection methods for various applications.
2. Scientific Rationale for Shorter Wavelengths: The patent itself highlights that while 254 nm is close to a DNA absorption band, "DNA action spectra show that absorption increases as the wavelength decreases, with a relative maxima at 260 nm and largest at 200 nm." Crucially, it notes that the "200 nm peak" and the "steep rise in absorption below 240 nm is exhibited by most proteins," which are "responsible for the steep rise in absorption." The patent further argues that "since we do not live underwater, the protein absorption band offers much more significant action spectra that can be used to alter the DNA of microorganisms more effectively." This provides explicit motivation for a PHOSITA to explore shorter wavelengths, such as 222 nm, for disinfection in air and on surfaces where water absorption is less of a concern. Similarly, the patent mentions 282 nm for targeting amino acids and other proteins.
3. Availability of Enabling Technology: The patent states that "new UV emitting lamps based on the excitation of excimers are becoming commercially available," and that these can "produce single line or narrow spectral emission at a wavelength determined by the gas composition of the lamp." This means the technical means to generate the desired specific wavelengths (e.g., 222 nm, 282 nm) were known and available to a PHOSITA. The selection of the gas to match the emission wavelength to the "absorption peak of the targeted biochemical" is explicitly taught as an advantage of NUV lamps.
4. Extending to Skin Disinfection: The general concept of UV disinfection is known. The patent explicitly teaches that the "present invention may be applied to skin disinfection" and that specific wavelengths like "207 nm and 222 nm may be particularly useful for skin and wound disinfection because they do not penetrate the epidermis, and 207 in particular does not damage human or animal cells." It also notes that "222 nm kills non-epidermis cells entirely, and therefore there is no concern of DNA mutation." Given the motivation to apply more effective UV disinfection broadly, and the known biological effects of different UV wavelengths, extending disinfection to human or animal skin, particularly with wavelengths identified as safer for skin, would be a logical and obvious design choice for a PHOSITA.

Therefore, a PHOSITA, seeking to overcome the limitations of 254 nm UV light and leveraging the scientific understanding of protein absorption peaks and the commercial availability of excimer lamps capable of emitting targeted wavelengths, would have been motivated to use 222 nm or 282 nm (or similar wavelengths effective against proteins) for faster and more efficient disinfection on various surfaces, including human or animal skin.

Obviousness for Claim 12 (Disinfection using at least two single line wavelengths from 222 nm, 254 nm, and 282 nm)

Claim 12: A process for destroying a DNA or RNA of a microorganism on a substance or surface comprising the steps of: generating photons of at least two single line wavelengths corresponding to a peak absorption wavelength of DNA or RNA, the at least two single line wavelengths being at least two of 222 nm, 254 nm and 282 nm; and directing the photons to the substance or surface to be disinfected, whereby the photons are selected to destroy a plurality of chemical bonds within the DNA or RNA of the microorganisms.

Combination of Prior Art References: General knowledge of UV disinfection (254 nm mercury lamps) + Scientific understanding of multiple UV absorption peaks in DNA/RNA and proteins (e.g., 200 nm, 260 nm, 280 nm) + Availability of excimer lamps (NUV sources) capable of producing specific narrow wavelengths + Motivation to achieve broader or more complete destruction of microorganisms/substances.

Motivation for Combination:
A PHOSITA would have been motivated to combine these elements for the following reasons:

1. Comprehensive Targeting of Biochemicals: The patent itself details that "Pyrimidine and purine bases of nucleic acids have a strong absorption near 260 nm," while "proteins also have an absorption maximum at about 280 nm." It also points to the "200 nm peak" for DNA absorption, attributed to proteins. Furthermore, it specifically mentions that "Test data confirmed that proteins in the RNA of the norovirus do not absorb the NUV wavelength at 222 nm effectively. However, a number of RNA proteins do exhibit strong absorption near the amino acid peak absorption of 280 nm." This illustrates that different components of microorganisms (DNA bases, various proteins, amino acids, RNA components) respond optimally to different UV wavelengths.
2. Maximizing Disinfection Efficacy: Given the diverse biochemical targets and their varying absorption spectra, a PHOSITA aiming for "high levels of disinfection on all types of contaminated surfaces and air" would logically seek to utilize multiple wavelengths to target a broader range of chemical bonds within the microorganisms or toxic substances. This would lead to more comprehensive and robust destruction.
3. Technological Feasibility: With the known prior art of 254 nm mercury lamps and the commercially available excimer lamps (NUV sources) capable of producing specific "single line or narrow spectral emission" at chosen wavelengths (e.g., 222 nm, 282 nm), it would be technically feasible to combine these light sources. The patent explicitly describes this, stating that the "NUV source may also produce 254 nm photons so as to target specific amino acids" and that an embodiment could use "two separate lamps" or a "dual annulus lamp" to emit both 207 nm and 222 nm simultaneously.

Thus, a PHOSITA, aware of the multiple critical absorption peaks in microorganisms and the availability of distinct UV light sources (including excimer lamps and existing mercury lamps) capable of producing these specific wavelengths, would have been motivated to combine at least two of these wavelengths (222 nm, 254 nm, 282 nm) to achieve a more potent and broad-spectrum disinfection effect.