HK1121233A - Method and apparatus for sterilizing and disinfecting air and surfaces and protecting a zone from external microbial contamination - Google Patents

Description

Method and apparatus for sterilizing and disinfecting air and surfaces and protecting an area from contamination by external microorganisms

Technical Field

The present invention provides a new method of disinfecting and sterilizing air, various types of surfaces, and food products from microorganisms and toxic chemicals. More particularly, the present invention relates to a method and apparatus for protecting surfaces in an enclosed or captured environment (area) from exposure to external sources of microbial contamination in an efficient and cost effective process. These areas may be large volumes such as high-rise buildings, cruise ships, jet airliners, or small volumes such as small rooms or surgical fields in hospital operating rooms or on the battlefield.

Background

All prior art techniques for sterilizing and disinfecting air are based on the use of commercially available Ultraviolet (UV) lamps or by using magnetic fields. The lamps are either pulsed or continuous. The continuous lamp is mercury based and emits light predominantly at 254 nm. Many companies are producing UV light based devices for destroying viruses, bacteria, spores and pathogens (microorganisms or VSP) in indoor air. This is an effective treatment because it continuously exposes the indoor air stream to the treatment light and has sufficient exposure time to the VSP over time. The required exposure time is 10-100 seconds, depending on the light absorption capacity at 254nm of different viruses and bacteria. This is effective for treating indoor air in a single room, but is not applicable for treating large flows of air that rapidly pass through large ducts. Its long treatment time is not practical for treating most surfaces.

Magnetic-based devices also require time to deactivate or destroy these VSPs. Two such inventions are directed to specific applications. Wesley, U.S. patent 4,458,153, is specific to liquid substances enclosed in tubes, but does not discuss any test results. United states patent 5,750,072 to Sangster requires the magnetic field to be sprayed with a sterilizing fluid in the form of a mist or vapor to generate free radicals which in turn kill the VSP. He did not discuss any test results. U.S. patent 4,524,079 to Hofmann is directed specifically to treating food products. He talks about the need for up to 100 pulses at a frequency of 5-500 kHz. These patents are not admitted to be prior art by their mention in the background section. Although the action time can be relatively short, the power required to treat a large area and the design of the equipment limit its practical application.

The broad ultraviolet spectrum has been divided into three regions depending on its different effects on biological systems. Referring to these regions primarily in medical terminology, UV-A is defined as the range or band of 320-400nm, UV-B is defined as the band of 280-320nm, and UV-C is defined as including wavelengths shorter than 280 nm. Photochemists and photobiologists do not generally use these terms because the absorption spectra of chemical bonds are much narrower than these conventionally defined bands. Instead, they use the wavelength of the applied radiation to define the observed effect.

It has been claimed that UV-C radiation is used to kill DNA. This is due to the mercury lamp emission at 254nm being close to a good DNA absorption band. None of these claims relate to any shorter wavelength and primary DNA protein absorption band with a peak at 200nm (see FIG. 9). Indeed, all literature directs researchers away from utilizing any shorter wavelength because of the high absorption of molecular water. Mercury lamps are used for wastewater treatment and are well suited for this application. However, this specification teaches that the protein absorption band provides a more important spectrum of action that can be used more effectively to kill microbial DNA since we are not living underwater. This concept is an important advance and step change in the technology used for sterilization and disinfection.

Over the last few years, new UV emitting lamps based on exciting excimers have become commercially available. These emitters produce a single line or narrow spectral emission at a wavelength determined by the gas composition of the lamp. If the wavelength of the treatment lamp is chosen to closely match the protein absorption peak of the microbial DNA, the lethal dose can be delivered to the VSP in a shorter time. No patents have been found that teach the use of a Novel Ultraviolet (NUV) source in combination with auxiliary equipment that can effectively and efficiently sanitize and disinfect large volumes of air, large and small surfaces, and food products in various preparation stages.

In this specification, sterilization refers to sterilization or high level of disinfection as specified by the US FDA. The term disinfectant or disinfection refers to all other levels of disinfection.

(NUV background)

The genome composition of all living organisms is contained in their DNA molecules. Replication occurs through the division of a DNA molecule, which replicates itself through its structural transformation. Some DNA molecules have been named, for example, pyrimidine bases, cytosine, thymine or uracil, which form a group of life-sustaining biologicals. Long DNA molecules are held together by the use of simple linkages similar to those found in sugars.

Researchers believe that the energy of the UV photons causes the formation of strong (covalent) bonds to develop between particular biochemicals. However, the bond energy of the covalent bond is very dependent on the relative positions of the participating atoms. When the bond is bilaterally symmetric to a hydrogen atom therein, it is called a dimer. Dimers are strong bonds and are not generally broken during evaporation of the liquid. UV light is known to produce thymine, cytosine-thymine, and cytosine dimers. After dimer formation, further replication of the DNA is stopped. FIG. 8 shows the principle of dimer formation in DNA molecules.

The DNA molecules absorb light from about 180nm to about 300 nm. The most effective wavelength in water is about 254nm, because water absorption steadily increases as the wavelength drops below 240 nm. DNA absorption also increases as the wavelength decreases. FIG. 9 illustrates this relationship (Von Sonntag; diagnosis by free radifications and UV-radiation. Water Supply 4, 11-18 (1986)).

Commercial light sources for UV irradiation close to the 260nm absorption peak of DNA have been produced by using mercury as the source for generating photons. The mercury gas in the lamp and its pressure determine the wavelength of the emitted light. For Low Pressure (LP) lamps and low pressure high intensity (LPHO) lamps, the emission wavelength is 254 nm. For medium pressure lamps, the emission wavelength is from 200nm to over 300 nm. However, the emitted light intensity is below 245nm, which is ineffective for continuous emission lamps and below 235nm, which is ineffective for medium voltage lamps. Xenon in a pulsed lamp produces similar emissions as a medium pressure mercury lamp.

The DNA action spectrum shows an increase in absorption with decreasing wavelength, a relative maximum at 260nm and a maximum at 200 nm. Many documents indicate that the main action spectrum of DNA absorption is 245-280nm, and no 200nm peak is indicated. As the water absorption increases significantly below 235nm, it becomes clear that: the DNA effectiveness curve omitting the 200nm peak is only applicable to organisms in water.

The MS-2 phage is a tagged virus that is used to measure reproductive capacity after UV irradiation. FIG. 10 is DNA uptake without the influence of water (Gates, F.L A study of the bacterial activity of ultra violet light III. journal. general Physiology 14, 31-42 (1930)). The absorption is not more than doubled at 222 nm.

Recent technical literature (Peak et al, UV action spectra for DNA dimer induction, photochemistry and Photobiology, 40, 5 (613-. The absorption of other molecular groups in long DNA strands increases as the wavelength decreases from 254 nm. Damaging or destroying these bonds may be more effective in deactivating DNA than in the 254nm band. No one has made a detailed study of the effectiveness of the inactivation of different single line UV emitters produced by a new UV source (NUV) excimer lamp. The report shows that the damage caused by 254nm light can be reversed by longer wavelength UV and blue light (fig. 12). Photons with higher energy of 222nm are not expected to cause this "photo-reactivation" phenomenon. However, this theory also needs to be confirmed.

Excimer lamps emitting at 222nm are considered the most efficient light source because DNA strands and organisms have greater absorption at this wavelength. All proteins showed a sharp increase in absorption below 250 nm. It has been well established that peptide bonds are responsible for the sharp increase in absorption exhibited by all proteins. This also occurs for nucleoprotein, aromatic amino acids, diglycine, triglycine and bovine albumin (McLaren, et al, Photochemistry of Proteins and nucleic acids, Pergamon Press, Macmillan Company, 1964). An organic chemist suggested that this lower wavelength was more effective at breaking bonds and forming dimers in purine bases and phosphate sugars rather than pyrimidines. The 222nm light is not strongly absorbed by water vapor and oxygen in the air. For long irradiation distances in air, shorter wavelengths may become very certainly ineffective by water vapor and oxygen absorption. Shorter wavelength radiation can significantly increase the generation of ozone, which is harmful to both humans and animals.

Test of

A comparison test was carried out with and without water using a lamp emitting 222nm light to determine the effect of this irradiation on the organism. The organism used in all experiments was a MS-2 virus that has become a standard indicator of the effectiveness of mutations. EPA reports (811-R-96-002) that mercury lamps at 254nm are used at more than 128mj/cm²The mean log reduction of the MS-2 virus at irradiance of (1) was 4.3.

The three wavelengths detected were 222, 253, 259 nm. The 222nm lamp was tested at three irradiance levels with the virus in a thin layer of water to reduce the water absorption effect. Additional separate experiments were also performed with the virus in more water. 253 and 259nm lamps were tested with the virus in water at the same irradiance level. All tests were controlled and a test tray was prepared on each lamp to check for experimental error.

222nm lamp (FIG. 11) at 40mj/cm²Irradiance of (3) produces a reduction of log5 to 60mj/cm²Produces a log6.5 reduction in irradiance. The water test produced a log reduction of 3.2, which matches the equivalent calculated irradiance in air. 253 and 259nm lamps at 60mj/cm²With an irradiance yielding a reduction of approximately log 4. A 300 million reduction in virus number is approximately 10-100 times more effective than the reported 254nm mercury lamp results under the same irradiance.

(analysis)

The test results show that 222nm light is very effective in causing mutations in organisms. These tests show a 10-1000 fold increase in intensity depending on the lamp. It is important to note the improvement of 259nm light source compared to 254nm light source. This produced a 10-fold increase in the test sample. It illustrates the importance of using UV photon emitters close to the absorption peak of DNA or target chemicals such as proteins, nucleic acids or amino acids.

It is important to note that the DNA biochemical will have different absorption spectra and the absorption peaks will be shifted by water, PH, temperature, previously absorbed light and environmental contaminants in the air. The presence of ozone can significantly reduce the damage resistance and shorten the action kill time. For some applications, ozone is prepared to increase killing efficiency.

For example, tyrosine has a relative maximum at 275nm, a 20nm red-shift relative to the standard DNA curve. The tobacco mosaic virus has a peak at 265nm, but its X-protein peak at pH7.3 is 280nm, while the RNA peak appears at 260 nm. The key to the destruction of a living organism is to align the correct biochemical so that a critical dose can be delivered in the shortest amount of time. The critical dose refers to a dose that destroys or deactivates the organism and prevents its replication.

Excimer lamps are of a coaxial design which can be made as small as a pencil to as large as 1 meter long. Lamp efficiency is approximately equal to mercury at wall power (wall power) of 10-25% of UV emission. The design has several advantages over mercury lamps. Most importantly, its gas can be selected to maximize its emission to the absorption peak of the targeted biochemical. Unlike mercury lamps, the excimer intensity can vary from near 0 to a maximum. Depending on the lamp specifications, it produces 10 to 1000 times more intensity than mercury lamps, and such lamps do not use mercury, which the EPA will soon regulate.

The energy of the emitted photon is determined by its wavelength. The photon energy at 250nm is about 5ev, and the energy increases with decreasing wavelength. Different bonds in DNA will be affected by photons of different energies.

Figure 12 illustrates the 254nm dose required to deactivate different VSPs. Bars represent with (solid) and without (open) light reactivation, respectively. It should be noted that 75mj/cm is required to inactivate the MS2 phage virus and prevent light reactivation²The dosage of (a). In the experiment shown in FIG. 11, half the dose at 222nm was just as effective as the higher dose at 254 nm. Even with the sample under water, 222nm radiation is still more effective than 254nm radiation.

The 222nm photon has more energy and can be absorbed by S-N, S-O, O-H and many carbon bonds that do not absorb 254 nm. This indicates that 222nm light can also prevent the reported DNA repair for low level 254nm UV sources.

(toxic gas weapons)

Biotoxins and nerve agents may be used by terrorists as weapons against populations. No economic means have been developed to mitigate attacks and prevent loss of lives and disable them at the time of the attack. While U.S. government agencies have developed detectors that can be used in the future to warn people in the enclosure under an attack, nothing can defeat the attack.

Biotoxins and neurotoxic agents are or include DNA or organic molecules with long chain carbon molecules. Both of which are easily destroyed with NUV sources. 222nm will break the C ═ C and C ═ O bonds, which will lead to destruction of the chemical.

The most effective method of delivering these agents is to propagate them in the gas phase through an air ventilation system. A detector is used to turn on sufficient NUV sources to destroy the agent before it exits the ventilation system into the confined area where the captured population is located. The tests still need to be conducted in a laboratory that can be adjusted and controlled to develop the criteria that these light sources are effective and become the first line of defense. However, the concept of using NUV sources and associated support equipment to process VSPs is valid and is also included within the scope of this specification.

(support equipment included in the device)

Important to sterilization and disinfection equipment is a high electric field electrostatic precipitator (ESP). Fig. 13 compares the range of effectiveness of mechanical filters for different contaminant sizes. As illustrated in the fourth column, it is able to eliminate VSP. However, since it can also capture fog and smoke, ozone O is present₃Ability to decompose into oxygen. Its use avoids ozone levels exceeding EPA radiation safety levels.

The apparatus includes a humidification system to provide and maintain a minimum water content at a predetermined and controllable level. In addition, the apparatus contains baffles and zone restriction devices that enhance zone protection and minimize the positive pressure required to maintain the protected zone.

Disclosure of Invention

The key to this approach is the development of New Ultraviolet (NUV) sources that emit single-line photons corresponding to the maximum absorption band of DNA. A preferred embodiment is a NUV source at 222 nm. This spectral emission is more efficient than the standard 254nm photon 10 when used to destroy DNA⁴And (4) doubling. The killing time is shortened from 10-100 seconds to less than 0.1 second. The photon energy of the NUV source is high enough to break the carbon bonds of the chemical toxins in a similar action time. The only way to achieve short action (kill) times is to determine the specific wavelength required to destroy the target organism or chemical. The NUV source is selected to provide a single line emission that matches the absorption peak of the target organism or chemical.

This advantageously creates an economical method for sterilizing and sanitizing air, surfaces and food items during daily life, avoiding the prior need to limit the occupation and use of the treated area. Furthermore, the device is capable of effectively and efficiently disinfecting floors, handrails, objects that are frequently touched by passers-by, with the aim of preventing the spread of diseases and toxic substances that may cause injury or illness to these people. NUV irradiation may be applied to any item or surface that requires disinfection and/or sterilization. The test will determine the correct irradiation limits to avoid any deleterious effects that may occur when used to disinfect human skin, hands, animal epidermis, such as skin, fur, and hair, and critical plastics and materials used in medical devices.

Because the NUV source is a light source, it can be directed through optical fibers to illuminate different levels of thick material to distribute the light intensity. One example uses a NUV source to disinfect the floor by directing it at the floor, by directing some light through a fiber optic buried in a brush to the bottom of a carpet or a floor scrubbing brush. In a similar manner, products having cavities or areas that are not directly illuminated by an external light source may be sterilized.

The NUV source can be used to directly disinfect the surfaces of a room or particles and microorganisms in the room air by irradiating all objects for the required irradiation time. Several light sources may be used in combination to ensure that all surfaces are illuminated and to shorten the total illumination time. A room contaminated with biological agents can be treated by moving the NUV source in many directions and moving it (them) around the room during treatment.

Normally breathable air contains many contaminants including water droplets, dust, fluff, bacteria, viruses, cists, spores and possibly toxic gases. The NUV source alone may be used to disinfect air. Sterilization sometimes requires removal of all particles to the smallest possible size. NUV sources generate by-products that must be removed for certain processing applications. These byproducts include oxidized air (ozone), condensable chemical byproducts, and damaged microorganisms. It is critical to the equipment that these contaminants and by-products be removed. In some special applications, ozone is added to make the treatment more effective. Thus, the apparatus includes a high E-field precipitator, an ozone generator and an ozone destruction lamp, as well as means for effectively utilizing a combination of these techniques.

The sterilized air is then used to prevent microbial contamination of the protected area by preventing the inflow of untreated air from the outside. The apparatus includes a pressurizing device and a zone shield that provides sufficient outflow from the protected zone so that no contamination occurs. The protected area may be as small as an injured area on a battlefield operating table, as large as a passenger ship, an airplane, or a high-rise building with thousands of people.

The main sources of infection and terrorist activity are directed to food and material processing. Photon emitters have been used for many years to effectively clean food and surfaces. However, the present invention uses NUV sources, which makes it less costly to treat food and material surfaces, since the action time is almost instantaneous. The apparatus of the present invention can irradiate food products in transport assemblies, stationary carts, and processing lines during transport from warehouse to food preparation processes. It may also be used to sterilize/disinfect medical or critical components on an assembly line prior to packaging.

Drawings

Fig. 1 is a schematic perspective view of a preferred embodiment of the invention in which the important components of the NUV source are located.

Fig. 2 is a schematic perspective view of a preferred embodiment of the present invention in which the critical components for sterilizing or sanitizing large volumes of air are located.

Fig. 3 is a perspective schematic view of a preferred embodiment of the present invention in which the important components for disinfecting floor surfaces and other surfaces such as chairs, armrests, counter tops, trays, table tops, and the like are positioned.

FIG. 4 is a perspective schematic view of a preferred embodiment of the present invention in which important components for sanitizing food prior to processing by a cook or chef are positioned prior to serving to people.

Fig. 5 is a perspective schematic view of a preferred embodiment of the present invention in which important components for disinfecting air used to cover and protect the area around a surgical procedure or procedure independent of the surgical site are located.

Fig. 6 is a perspective schematic view of a preferred embodiment of the present invention illustrating a regional air disinfection apparatus in combination with a remotely protected operating field.

Fig. 7 is a CFD chart of a preferred embodiment of the present invention defining a pattern of air flow emitted by the disinfection device that is used to cover and protect the area around the surgical procedure or procedure independent of the surgical site.

FIG. 8 is a graphical representation of dimer formation in a DNA molecule.

FIG. 9 is a graph of UV absorption of DNA plotted against wavelength.

FIG. 10 is a graph of DNA uptake plotted without the influence of water.

FIG. 11 plots the effectiveness of UV irradiation at different wavelengths for reducing MS-2 phage virus.

Figure 12 plots the UV dose required to achieve 4 log deactivation for selected microorganisms.

FIG. 13 is a comparison of various filter effectiveness ranges for removing particulate matter from air.

Detailed Description

The drawings illustrate the different forms of the invention and the equipment required to disinfect the air and surfaces containing the VAP. Fig. 1 illustrates a NUV source. Figure 1a shows a NUV source installed in an air channel. The high-voltage electrode 1 is located in the inner tube of the annular lamp. The ground electrode screen 2 is located outside the ring-shaped lamp. The gas generating UV photons is located in an annular region 3 between the inner and outer tubes 4. The gas type is selected so that the emitted UV photons are absorbed by the target microorganism or chemical. The preferred embodiment is 222 nm. The UV radiation is emitted radially outwards 5. The voltage or current between the two electrodes is varied to vary the amount of UV radiation generated.

Fig. 1b illustrates a NUV source for directing UV photons to specific locations. The NUV source is shown in the center of the figure as an end view. The special reflector 6 in the end view incorporates a special "gull-wing" design so that more than 90% of the emitted light is directed to the underlying plane. The special reflector 6 is also made of barium sulfate (Ba)₂SO₄) As a reflective material to maximize the number of photons reflected onto the plane. In some cases, the cover 6a is essential to protect the NUV source and reflector from dust. The cover transmits 222nm light. The dedicated reflector may also have different shapes to vary the directed irradiation for different applications.

In use, the NUV source may be made of any size and length. In the air channel, as in the embodiment shown in fig. 2, the part 6b would have the NUV source supported from the side, top or bottom of the duct so that its irradiance would be conveyed parallel to the air flow. For particular applications, the second embodiment, part 16 of FIG. 5, would have the NUV source and cylindrical reflector supported inside the duct so that the irradiance is perpendicular to the air flow. One example of this embodiment is a NUV source located in the center of the tumble dryer. During the drying process, all garments are irradiated for a length of time that will ensure sterilization.

Figure 2 illustrates the equipment required to sterilize and disinfect the air stream in large pipes. The NUV source 7 is located a distance before an electrostatic precipitator (ESP)9 that may allow a short exposure time to complete the destruction of the toxic gases or VSPs. A humidifier 10 may follow the precipitator with a control sensor 11 so that the humidity of the outgoing air can be selected and maintained. One or more blowers 12 may also be used to pressurize the outgoing air so that a slight pressurization may be applied to the protected area to prevent the ingress of contaminated air. Depending on the nature of the zone, a confining baffle (not shown) is used to assist in maintaining a positive pressure within the protected zone.

Figure 3a illustrates the NUV source 13 located in the front box of a vacuum cleaner or floor cleaning machine. The vacuum cleaner may be of the upright floor type or of the canister type. It may also be any device capable of supporting and carrying a NUV source close to the floor. The main part is that the NUV source with reflector 6 consists of the components described in fig. 1 b. Figure 3b illustrates a preferred embodiment of the NUV source contained in a hand held wand. A sensing switch 14 may be included in this embodiment that turns off the NUV source when the wand is not properly directed at the surface desired to be treated.

Figure 4a illustrates the NUV source located on a conveyor that carries raw and unformulated food prior to kitchen cooking and an industrial packaging line that carries product that needs to be sterilized. The conveyor assembly 24 is designed to maximize the surface area illuminated by the NUV source. In some cases, several light sources 13 are required because the illuminated surface of the food or product cannot be changed to illuminate the entire surface during the illumination time of one NUV source. Reversing gears or vibrators are typically used to redirect the food products and they move along the conveyor belt. Fig. 4b illustrates one or more NUV sources 13 located next to heat lamps 15 or other heating surfaces, which heat lamps 15 or other heating surfaces are used to keep food hot at a service counter before the food is served from the kitchen to customers. In another embodiment, the NUV source is used to irradiate cool or cold food, so no heating lamps 15 are used.

Fig. 5 illustrates the NUV source located in an air sterilization apparatus that provides air to a remote and separate operating table. The NUV source 16 is located inside the UV reflector chamber 17 to reduce the loss of UV photons. The light trap 18 blocks the UV light before turning vanes 19(turning vanes), which vanes 19 direct the air flow vertically downwards towards the surgical site. The diffuser 20 ensures that the air flow is uniform through the duct. A high E-field electrostatic precipitator (ESP)21 follows the diffuser to remove particulates and reduce all ozone to oxygen. The air stream then passes through a second diffuser and humidifier 22 to ensure that the air stream passes uniformly through the duct and the humidity level is controlled at a predetermined value. Fig. 6 illustrates how the air sterilization apparatus may be used in conjunction with a remote surgical site where a surgeon is using teleoperated surgical instruments located in the sterile air region. Fig. 7 illustrates an air flow pattern using a CFD computational fluid design that ensures that the air above the surgical field is uniform and inhibits contaminated air from entering the protected field.

Although preferred embodiments of the present invention have been described herein, the foregoing description is merely exemplary. Further modifications of the invention herein disclosed will occur to those skilled in the relevant art and all such modifications are considered to be within the scope of the invention as defined by the appended claims.

Claims (20)

1. A disinfection apparatus, comprising:

a photon source of 222nm wavelength; and

a photon reflector spaced from the photon source and fixed,

the device thereby generates photons that are directed to a selected area or surface and are effective to destroy the DNA of the microorganism.

2. The apparatus of claim 1, further comprising a source of discrete wavelength photons other than 222 nm.

3. The apparatus of claim 1, wherein the 222nm photon source is an excimer lamp.

4. The apparatus of claim 1, wherein the photon reflector is a gull-wing shaped director selected to direct at least 90% of the emitted light to a plane.

5. The apparatus of claim 1, the photonic reflector comprising barium sulfate for enhancing its reflective properties.

6. An apparatus as claimed in claim 1, further comprising a floor cleaning device, the photon source being fixed to the floor cleaning device in a position suitable for impinging photons on a floor.

7. The apparatus of claim 1, further comprising:

a handle attached to the photon source; and

a surface detection mechanism adapted to turn off the photon source when the photon source is not proximate to the surface to be disinfected.

8. The apparatus of claim 1, further comprising:

an air channel surrounding the photon source; and

a particle removal device in the passage spaced from said photon source, the photon source being selected to provide a specific action time in the air stream to disinfect the air.

9. The apparatus of claim 8, wherein the particulate removal device is an electrostatic precipitator.

10. The apparatus of claim 8, further comprising a humidifier in the air channel downstream of the electrostatic precipitator.

11. The apparatus of claim 10, further comprising a humidity sensor downstream of the humidifier.

12. The apparatus of claim 8, further comprising an optical trap disposed between the photon source and the particle removal device.

13. The apparatus of claim 8, further comprising turning vanes within the channel to change the direction of the air flow.

14. The apparatus of claim 8, further comprising a diffuser.

15. A method for disinfecting a substance, comprising the steps of:

generating photons with a wavelength of 222 nm; and

the photons are directed to the substance to be disinfected so that the photons destroy the DNA of the microorganisms.

16. The method of claim 15, wherein the photons are directed to a desired surface by reflecting the photons.

17. A method for disinfecting a substance in an air stream, comprising the steps of:

directing an air stream to a 222nm photon source; and

the air stream is irradiated with 222nm photons, whereby the photons destroy the DNA of the microorganism.

18. The method of claim 17, further comprising the steps of:

determining the required action time of the disinfecting air flow; and

the particulate matter is removed from the air stream after the action time.

19. The method of claim 18, further comprising the step of humidifying the air stream after the removing step.

20. A method for providing a sterile surgical space, comprising the steps of:

directing an air stream to a 222nm photon source; and

illuminating the air stream with 222nm photons;

removing particulates from the air stream; and

the air flow is directed vertically downwards towards the operation area, so that the sterile air flow surrounds the operation space and prevents the ingress of contaminated air.