WO2002065972A2 - Method for disinfecting fresh air, air disinfection module, cpap device, air humidifier, breathing apparatus, flashlamp and gas discharge lamp - Google Patents

Abstract

The aim of the invention is to improve hygiene in medicine, especially with respect to CPAP and breathing apparatuses. This is achieved by exposing the air which is to be inhaled by a patient to electromagnetic radiation, whereby bacteria and germs are heated and subsequently destroyed.

Description

 Fresh air disinfection process, air disinfection module, CPAP

Device, humidifier, respirator, flash lamp as well

Gas discharge lamp

The invention relates to a method for disinfecting fresh air, an air disinfection module, a CPAP device, a humidifier, a respirator, a flash lamp and a gas discharge lamp.

It is known that radiation can damage cells in various ways. Microwaves primarily work by being absorbed by the water in the cells. This energy absorption leads to the heating of the cell. Infrared radiation is absorbed by the organic molecules and water, but mostly only on the surface of the cells. The low penetration depth of the radiation means that the interior of the cell is only heated by heat transport. Light in the visible range is partially absorbed, but not nearly as strong as infrared or microwaves. The heating of the cell either leads to cell death via protein coagulation or, with a correspondingly high radiation output, to boiling and bursting of the cells.

UV light is able to split organic molecules.

It follows from this that the different types of radiation, that is to say the different frequencies of the electromagnetic spectrum, kill different types of germs with different degrees of effectiveness. Highly water-containing cells are most effectively thermally destroyed with microwaves. Moderately hydrated cells can be effectively combated with selectively selected infrared radiation. Low-water germs (spores), on the other hand, are more likely to be killed by destroying the organic components using UV light.

On the website http://www.stermax.com.br/ingles/i_pr_a20.htm two devices for air sterilization are offered. The devices work with a ceramic block through which holes are drilled in the vertical direction and wires made of a nickel-chromium alloy are drawn. The wires are heated electrically up to 350 ° C. Due to convection, the ambient air passes through the Ceramic block from bottom to top. The high temperatures and the associated infrared radiation kill fungal spores, bacteria and microorganisms in the air.

The VitaTech UV-Systeme GmbH (http://www.vitatech.de) offers systems for water purification with ultraviolet radiation.

HOWATHERM Klimatechnik GmbH (www.howatherm.com) also offers a UV disinfection module for air disinfection with UV light in buildings with the highest hygiene requirements such as hospitals (HLH, Volume 51 (2000) Issue 7, pp. 24-31) ,

The intensive use of chemical disinfectants has led to major septic problems in the hospital sector. Increasingly resistant, pathogenic germs and general human intolerances are known consequences. Symptomatic symptoms, such as "building related illness" or the "sick building syndrome" are generally known today. Chemical-free disinfection techniques include Wekhof, A: Flash disinfection and pollutant degradation, GIT-Labor trade journal 8/2000, page 930-932, Wekhof, A: Destructive rays - flash systems for optimal disinfection, Pharma Food, Hütting, March 2000; Trageser, M: Detoxification with UV-activated oxidation, Kaff 6-2000, page 54/55.

Non-invasive ventilation is becoming increasingly important. Non-invasive ventilation is widely used in the therapy of sleep-related breathing disorders with CPAP devices (CPAP: continuous positive airway pressure). The CPAP therapy is in Chest. Vol. 110, pages 1077 to 1088, October 1996 and Sleep, Vol. 19, pages 184 to 188.

In CPAP therapy, a constant positive pressure is applied to a patient through a nasal mask. If the overpressure is selected correctly, this ensures that the upper respiratory tract remains fully open throughout the night and thus no obstructive breathing disorders occur. The pressure required depends, among other things, on the stage of sleep and the body position of the Asleep. A therapy device (AutoCPAP) is known from DE 198 49 571 A1, which automatically adjusts the ventilation pressure and thus adapts to the sleep stage and the body situation. There are also breathing support devices that support the patient's inhalation and exhalation by lowering the pressure when exhaling. They are referred to as BiPAP or multilevel devices. In this application, the term CPAP device is used as a generic term for AutoCPAP, BiPAP and multilevel devices, since they all create overpressure in the patient's airways and therefore have a similar effect.

A major problem is the drying out of the nasal mucous membranes, which in addition to the unpleasant irritation of the nose also prevents effective therapy. Usually, additional humidifiers are prescribed against this side effect.

Due to the high humidity of the air exhaled by the patients, a back diffusion of the exhaled air through the ventilation hose and the lower temperature in the compressor compared to the temperature of the exhaled air, water condenses in the housing of the compressor. In connection with fine dust, a breeding ground for microorganisms forms especially in the cracks and pores of soundproofing foams. Germs can get to such breeding grounds from the environment and from the patient himself. From there, infections get to the next patient as well as to the environment with the air, which is particularly problematic when the devices are used in different clinics. Regular disinfection of these devices is only possible with gases because the electronics built into the devices do not survive the temperatures required for disinfection. Due to the numerous poorly accessible cavities in the device, a long penetration time of the gases and an equally long flushing time after the disinfection must be guaranteed.

Apart from CPAP therapy, ventilators are used as respirators in the field of intensive care medicine. In the neon catalog area, the air supply for incubators is regulated by ventilators. The object of the present invention is to provide a method for disinfecting fresh air, an air disinfection module, a CPAP device, a humidifier, a respirator, a flash lamp and a gas discharge lamp for effective disinfection in the medical field, including the home care area.

This object is solved by the subject matter of the independent claims.

Preferred embodiments are the subject of the dependent claims.

The advantage of disinfecting the air between the patient and the ventilator is that the corresponding ventilator (CPAP therapy device or respirator) has to be disinfected less frequently.

An advantage of the effect of electromagnetic radiation at a narrowed point is that the radiation density increases with the same output, thereby ensuring effective destruction of bacteria and germs.

The advantage of using microwaves is that microwave radiation is effectively absorbed by water and thus water-containing cells are very effectively thermally destroyed. In addition, microwave generators are manufactured in large numbers for microwave ovens, so that they are inexpensive available. The advantage of using UV rays is the killing of water-poor germs, in particular spores of fungi.

The advantage of a pulsed mode of operation is that the energy density of the electromagnetic radiation is higher during the pulse than if the electromagnetic radiation were to act continuously.

The advantage of using several disinfection stages is a more reliable disinfection and thus a longer operation of ventilators without cleaning, in particular gas disinfection. The method according to the invention and the air disinfection module can advantageously be used in patients with a weakened immune system, such as cancer patients who are undergoing chemotherapy. This reduces the risk of infection in the home environment.

The advantage of using a flash lamp is that the flash light has a high energy density.

The high energy density in the interior of the ring, ie close to the axis of symmetry, is advantageous in the ring-shaped design of flash lamps.

Preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawings. It shows:

1 is a respirator with humidifier and air disinfection module, which is equipped with a flash lamp,

2 a respirator with humidifier and air disinfection module, which is equipped with a gas discharge lamp,

3 is a hollow cylindrical flash lamp,

4 is an annular flash lamp, the outer and inner surfaces being spherical,

5 shows a hollow cylindrical gas discharge lamp,

Fig. 6 annular gas discharge lamp, the outer and inner surfaces are spherical, and

Fig. 7 shows a disinfection module.

FIG. 1 shows a compressor 1, the turbine 2 of which in the breathing tubes 8 and the breathing mask 12 has a slight excess pressure of up to 30 mbar the ambient pressure. The speed of the turbine 2 can be controlled via controller 3, so that the overpressure is also controlled indirectly via controller 3. After the compressor, the compressed air is preferably passed through a humidifier 4. The air sweeps past the surface of a water reservoir 5. The water reservoir is preferably heated by a heating plate, the temperature of which can be controlled by the temperature controller 7. In Fig. 1, a heating coil 6 is shown instead of the heating plate.

After the humidifier, the breathing air is passed through a waveguide 9 before it is fed to the face mask 12. Microwaves are coupled into the waveguide from the open end of the waveguide in FIG. 1. The other end of the waveguide is closed in order to form microwaves in the waveguide with a high energy density. The connections of the waveguide 9 to the breathing tubes 8 are covered by metallic grids, so that these connections are closed to microwave radiation but are air-permeable.

A lamp is arranged in the waveguide. FIG. 1 shows an example of a flash lamp 10. A flash lamp typically has three electrodes, namely a cathode to which 0 volts are applied in the drawing, an anode to which 400 V is applied as shown in FIG. 1, and an ignition electrode. The flash lamp flashes when a high voltage of several thousand volts (Fig. 1: 6000 V) is applied to the ignition electrode. A suitable choice of the light gas in the flash lamp ensures that the UV portion of the flash light is high and emission lines of the light gas coincide with absorption lines of the microorganisms to be destroyed.

The disinfectant effect of flash lamps is primarily due to the fact that they deliver a high energy density and thus lead to protein clotting or even to a boiling or bursting of the cells. The concentration of light in a short pulse largely prevents the microorganisms from releasing the radiant energy into their surroundings quickly enough by conduction. The inner wall of the waveguide 9 is mirrored in order to achieve the highest possible effect of the light. A mirroring of the waveguide on the inside can easily be achieved, since practically all pure metal surfaces reflect electromagnetic radiation including visible light due to their high conductivity. However, oxidation of the waveguide on the inside must be prevented, which can be done by gilding. The waveguide 9 is preferably air-tightly closed at its end shown in FIG. 1 by plastic. In this way, the air we breathe cannot contaminate the microwave generator. On the other hand, plastic is not conductive, so that it is almost completely permeable to microwaves.

Because of the clarity of the illustration, the waveguide was drawn larger than the ventilation tubes 8 in FIG. 1. In reality, however, the area remaining between the waveguide and the flash lamp should in particular be smaller than the cross-sectional area of the breathing tubes 8.

However, another light source can be used instead of a flash lamp. Fig. 2 shows a very similar arrangement as Fig. 1, with the same reference numerals designating the same parts. Instead of the flash lamp 10, however, a gas discharge lamp 30 is provided, in which the two incandescent filaments 31 and 32 are indicated. The electrical control of the two filaments is known. Mercury or amalgams can be used as illuminating gas 33 under a low pressure of a few μbar. The mercury atoms predominantly emit UV light with a wavelength of 254 nm. It is energetic enough to break the peptide bond between amino acids in proteins and destroy genetic material. This is the basis for the disinfectant effect of such low-pressure mercury lamps. A phosphor can also be provided on the outer surface of the gas discharge lamp in order to change the wavelength of the UV light so that it coincides with absorption bands of the microorganisms to be destroyed.

Excimer emitters are also suitable as light sources instead of flash or gas discharge lamps. The excimer emitters in particular generate light in a narrow wavelength range of a few nm, which is also from Microorganisms is well absorbed. The emitters mentioned generate light with a high UV component. As mentioned above, the disinfectant effect of UV light is primarily due to the fact that it splits organic molecules. The heating of the microorganisms by UV light is insignificant. The most important factor for the disinfection effect is the dose, which results from the power density multiplied by the duration of exposure. It follows that pulsed operation has no advantages with regard to the disinfection effect of UV light, because the higher power density is associated with a shorter exposure time. Similar to flash lamps, the above-mentioned spotlights with mirror optics are used to concentrate the UV light on the air to be disinfected. As mentioned above, this mirror optic can be formed by an internally mirrored waveguide.

The embodiments shown in FIGS. 1 and 2 advantageously combine the effects of microwaves with the effect of UV light. However, it is clear to a person skilled in the art that the lamp or the microwave source with a waveguide can be omitted if the disinfecting effect of the microwave radiation or of the light is sufficient.

In order to make the killing of germs even more reliable, two or more disinfection stages with flash lamps, UV lamps and / or waveguides for microwaves can be provided in other embodiments.

A flash lamp and / or a UV lamp can be replaced or supplemented by semiconductor lasers to take advantage of the germicidal effect of infrared light with high energy density.

In another preferred embodiment, the humidifier 4, the waveguide 9, the flash lamp 10 and a microwave generator are accommodated in a housing. In a further preferred embodiment, the assemblies of the compressor 1 are also accommodated in this housing.

After the breathing air has left the waveguide, it is partially supplied to the respiratory mask 12. Part of the air we breathe leaves Breathing tube through the exhalation opening 11. When the patient inhales, only a small part of the breathing air leaves the breathing tube through the exhalation opening 11. When exhaling, the exhaled air in particular leaves the breathing tube through the exhaling opening 11. However, some of the exhaled air also diffuses into the Ventilation tube 8 back.

Instead of the devices for CPAP therapy shown schematically in FIGS. 1 and 2, the invention can also be used with respirators. For this purpose, the exhalation opening 11 is connected by an expiration tube to a valve, via which the patient's exhalation is controlled. Another valve is arranged in one of the breathing tubes 8 in order to control the inhalation of the patient. In the case of a respirator, an air disinfection module can also be arranged in the expiration tube, which can consist of a waveguide, a flash lamp and / or semiconductor lasers.

All devices shown in Fig. 1 and 2 are supplied with a wipeable, largely closed housing. Only the connections for ventilation tubes are open. The air duct in the humidifier 4 and the waveguide with a connected microwave generator are - apart from the openings for the ventilation tubes - designed so that they are airtight, so that the devices can be operated even with slight overpressures and underpressures and air leaks are excluded.

One or more air disinfection modules can be integrated in a respiratory air humidifier. When the humidifier 4, waveguide 9 and flash lamp 10 or UV lamp 30 are integrated in one device, the microwave radiation and also the radiation from the flash lamp or the UV lamp can be used to heat the water reservoir 5 of the humidifier 4. In addition, the flash lamp or the UV lamp can be arranged in the humidifier so that part of the UV light generated by these light sources falls into the water reservoir 5 of the humidifier. In this way, the water reservoir is kept germ-free. Since the water is in the water reservoir, i.e. no microorganisms are subsequently supplied, a small amount of UV light is sufficient to keep this water germ-free. The one or more air disinfection modules can be close to the Air outlet, that is, the patient-side ventilation hose connection of the humidifier to prevent contamination of the humidifier by the patient.

One or more air disinfection modules can also be integrated in a CPAP device or a respirator. This allows the disinfection intervals of the devices to be extended. In particular, due to their self-disinfecting properties, the devices can be used in succession with several patients, for example, in hospitals, so that the duration of use is extended in comparison to the duration of maintenance. The air disinfection modules can be placed near the vent hose connector to prevent contamination of the CPAP or ventilator by the patient. Instead or in addition, air disinfection modules can be provided in the suction area of the devices in order to sterilize air that is inhaled. Such CPAP or ventilators can also include humidifiers.

In order to increase the energy density generated by flash lamps and thus their germicidal effect, ring-shaped flash lamps 20 or 27 according to FIGS. 3 and 4 are used. The air to be disinfected flows through the middle of the flash lamp. The air is guided to the flash lamp and away from the flash lamp by hoses drawn in dashed lines in FIGS. 3 and 4. The luminous gas 21, the anodes 24 and the cathodes 25 are located in a largely rotationally symmetrical, annular body made of glass, for example. The ignition electrodes 26 are located on the outer surface of the flash lamp. They act as mirrors and further increase the energy density inside the flash lamp due to their reflective effect. As mentioned above, practically all pure metal surfaces shine, so that good conductivity and a reflective effect are mutually beneficial. The outer electrode of the flash lamps can be made of aluminum. The glass body of the flash lamp protects the inward-facing side of the aluminum layer against oxidation. The conical surfaces of the flash lamp shown in FIG. 4 can be blackened. The required voltages are given in FIGS. 3 and 4 only by way of example and are identical to FIG. 1. The designs for flash lamps shown in FIGS. 3 and 4 can also be used advantageously for gas discharge lamps. For example, mercury can be used as the luminous gas. Sections through such gas discharge lamps are shown in FIGS. 5 and 6, respectively. The electrodes 24 and 25 are replaced by a filament 31 and 32, respectively. The outer lateral surface 41 can be mirrored in order to concentrate the UV light on the gas 23 to be disinfected.

FIG. 7 shows a further embodiment for a disinfection module 60 according to the invention. In this embodiment, light emitted by an intensive light source 61 is concentrated by optics 62 on a small spatial area. An ellipsoidal mirror is shown as an example in FIG. 7. The light source is located in a first focal point 63 of the ellipsoidal mirror. The small spatial area surrounds the second focal point 64 of the ellipsoidal mirror.

In order to achieve effective disinfection, the gas to be disinfected is passed through two funnel-shaped hose pieces 65 and 66 through the small spatial area around the second focal point 64. The two funnel-shaped pieces of tube are preferably transparent to the light used in a wide wavelength range. Arc lamps can be used as the light source 61 since they generate high-intensity light in a small spatial area, which can be focused again on a small spatial area. In other embodiments, halogen lamps can also be used. Halogen lamps are significantly cheaper than arc lamps, but do not achieve their light energy density.

Instead of the ellipsoidal mirror shown in FIG. 7, glass optics can also be used to focus the light generated by the light source 61 onto the small spatial area around the second focal point 64. The glass look can be supplemented by additional mirrors. The disinfection module according to FIG. 7 can be used together with other disinfection modules, the air to be disinfected passing through the disinfection modules one after the other. The invention was previously explained in more detail using preferred embodiments. However, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. Therefore, the scope of protection is determined by the following claims and their equivalents.

LIST OF REFERENCE NUMBERS

1. Compressor

2. Turbine

5 3. Controller

4. Humidifier module

5. Water reservoir

6. Heating coil

7. Temperature controller

10 8. Respiratory tubes

9. Waveguide

10. Flash lamp

11. Exhalation opening

12. Respiratory mask

15 13th patient

14. Metal grid

20. Annular flash lamp

21. Luminous gas

22. High-voltage reflective electrode

20 23. Gas to be disinfected

24. Cathode

25. Anode

26. Ignition electrode

27. Ring-shaped flash lamp

25 30. Gas discharge lamp

31. incandescent filament

32. incandescent filament

33. Illuminant gas

40. annular gas discharge lamp

30 41. mirrored outer surface

50. annular gas discharge lamp

60. Disinfection module

61. Light source

62. Optics 63. first focus

64. second focus

65. funnel-shaped tube pieces

66. funnel-shaped tube pieces

Claims

claims: 1.Procedure for disinfecting fresh air in ventilators with the steps: Conveying fresh air through a hose (8) under slight excess pressure to a respiratory mask (12); characterized in that the fresh air is exposed to strong electromagnetic radiation in part of the conveying path. 2. The method according to claim 1, characterized in that the conveying path has a section with a narrowed cross section and the electromagnetic radiation is mainly concentrated on this narrowed section. 3. The method according to any one of the above claims, characterized in that microwaves are used as electromagnetic radiation. 4. The method according to any one of the preceding claims, characterized in that infrared or UV radiation is used as electromagnetic radiation. 5. The method according to any one of the above claims, characterized in that the electromagnetic radiation is switched on and off in a pulsed manner. 6. The method according to any one of the above claims, characterized in that the electromagnetic radiation heats the water reservoir (5) of a humidifier (4). 7. The method according to any one of the above claims, characterized in that the method is part of a CPAP therapy. 8. The method according to any one of claims 1 to 6, characterized in that the exhaled air is discharged through an expiration tube and the exhaled air in the expiration tube is also exposed to electromagnetic radiation. 9. Air disinfection module with: an input port for supplying air; 5 an outlet port for exhausting the air; characterized in that the air between the input connection and the output connection is exposed to strong electromagnetic radiation. 10 10. Air disinfection module according to claim 9, characterized in that a constriction is provided between the input connection and the output connection, the clear cross section of which is smaller than that of a breathing tube and the air to be inhaled at this constriction of the strong electromagnetic radiation 15 is suspended. 11. Air disinfection module according to claim 9 or 10, characterized in that microwaves are used as electromagnetic radiation. 20 12. Air disinfection module according to one of claims 9 to 11, characterized in that infrared or UV radiation is used as electromagnetic radiation. 13. Air disinfection module according to one of claims 9 to 12, characterized in that the electromagnetic radiation is switched on and off in a pulsed manner. 14. Air disinfection module according to one of claims 9 to 13, characterized in that an air humidifier module (4) at the input connection. 30 is connected, the air disinfection module and the humidifier module being accommodated in a common housing and the electromagnetic radiation heating the water reservoir (5) of the humidifier module (4). 15. Air disinfection module according to one of claims 9 to 14, characterized in that the electromagnetic radiation is generated by a flash lamp (10), laser diodes or a UV lamp (30). 16. Air disinfection module according to claim 9, characterized in that the electromagnetic radiation is generated by a light source (61) with a high radiation density and is focused by optics (62) onto a small spatial area which has a focal point (64) of the optics (62) surrounds, whereby the air to be disinfected is passed through the small area. 17. Air disinfection module according to claim 16, characterized in that the intensive light source is an arc or halogen lamp. , , 18. Air disinfection module according to one of claims 9 to 17, characterized in that it is connected to a device for performing the CPAP therapy. 19. CPAP device with one or more air disinfection modules according to one of claims 9 to 18. 20. CPAP device according to claim 19, characterized in that the CPAP device further comprises a humidifier. 21. CPAP device according to claim 19 or 20, characterized in that the humidification modules between the turbine (2) and a connection for one Ventilation hose are attached. 22. Humidifier with one or more air disinfection modules according to one of claims 9 to 18. 23. Humidifier according to claim 22, wherein a UV light source is used for disinfection and the UV light of the UV light source partially falls on water, which is located in a water reservoir (5) of the humidifier. 24. Ventilator with one or more air disinfection modules according to one of claims 9 to 18. 25. The ventilator according to claim 24, characterized in that the 5 ventilator further comprises a humidifier. 26. Ventilator with several air disinfection modules according to one of claims 9 to 18, characterized in that air to be inhaled passes through the air disinfection modules one after the other. 10 27. Ventilator according to one of claims 24 to 26, characterized in that the exhaled air is discharged through an expiration tube and the exhaled air is passed through a further air disinfection module. 15 28. Flash lamp, characterized in that the illuminating gas (21) is enclosed in an annular transparent container and there is also an annular cathode (24) and an annular anode (25) in the illuminating gas and an ignition electrode (26) is arranged on the outside of the annular container it's so 20 that the annular container, cathode, anode and ignition electrode, apart from the contacts on the electrodes, are essentially rotationally symmetrical. 29. Flash lamp according to claim 28, characterized in that the 25 ignition electrode acts simultaneously as a mirror. 30. Flash lamp according to claim 28 or 29, characterized in that the annular container has essentially the shape of a hollow cylinder (20). 31. Flash lamp according to claim 28 or 29, characterized in that the outer surface of the annular container forms part of the surface of a large ball and the inner part of the annular body forms part of the surface of a small ball (27). 32. Gas discharge lamp, characterized in that the luminous gas (33) is enclosed in an annular transparent container and there are also two largely annular glow electrodes (31, 32) in the luminous gas, so that the annular container and the two glow electrodes, from the contacts 5 of the glow electrodes are essentially rotationally symmetrical. 33. Gas discharge lamp according to claim 32, characterized in that the annular container is mirrored on the outside. 10 34. Gas discharge lamp according to claim 32 or 33, characterized in that the annular container has essentially the shape of a hollow cylinder (40). 35. The gas discharge lamp as claimed in claim 32 or 33, characterized in that the outer surface of the annular container forms part of the surface of a large sphere and the inner part of the annular body forms part of the surface of a small sphere (50). 20