GB2402066A

GB2402066A - Apparatus for disinfecting a surface

Info

Publication number: GB2402066A
Application number: GB0311958A
Authority: GB
Inventors: John George Chewins
Original assignee: Bioquell UK Ltd
Current assignee: Bioquell UK Ltd
Priority date: 2003-05-23
Filing date: 2003-05-23
Publication date: 2004-12-01
Anticipated expiration: 2023-05-23
Also published as: JP2007503960A; RU2005140286A; US7967800B2; GB0311958D0; BRPI0410601B1; RU2330690C2; CN1822875A; GB2402066B; CN1822875B; EP1626767A1; BRPI0410601A; CA2526644C; US20070163935A1; UA88612C2; ES2328358T3; EP1626767B1; ZA200509587B; KR100984385B1; CA2526644A1; NO20055954L

Abstract

An apparatus for disinfecting a surface, in particular a wound surface, with aqueous ozone. The apparatus comprises a fluid containing reaction vessel 7a with one or more inlets and outlets. Fluid leaves the vessel via inlet 9 and enters a recirculation loop. Gaseous ozone is introduced into the fluid within the loop via means 6. The ozonated fluid re-enters the vessel via nozzle 8. Ozone gas bubbles are prevented from re-entering the recirculation loop due to the shape of inlet 9 and instead leave via outlet 13a and enter an ozone destructor. The oxidation reduction potential and the ozone capacity of the fluid within the vessel can be measured via sensor 13. A spray head 24 is provided to supply the ozonated fluid in the vessel to the surface to be treated when required and means are provided to collect and contain the fluid thereafter.

Description

- 1 - 2402066 Apparatus for Disinfecting a Surface This invention relates

to apparatus for use in the disinfection of surfaces and wounds using aqueous ozone.

Wounds can be divided into two basic categories, acute and chronic.

Acute wounds are caused when damage occurs to external intact skin tissue. This includes surgical wounds, bites, burns, cuts, abrasions, lacerations and more traumatic crush or gunshot wounds.

Chronic wounds are associated with endogenous mechanisms connected to a predisposed condition that eventually damages the dermal tissue. Chronic wounds often result when the supply of oxygen and nutrients (perfusion) to tissues is impaired. Reduced arterial supply, venous drainage or metabolic diseases can cause chronic wounds. Leg ulcers, foot ulcers and pressure sores are all examples of chronic wounds.

Hunt et al (1997) state that acute wounds will heal rapidly if blood perfusion is maximised, thus providing the cells of the immune system the oxygen and nutrients necessary to ward off infection. Oxygen is an integral requirement for cell growth, division and wound healing (Grief et al, 2000). It is also critical for the respiratory burst of Polymorphonuclear leukocytes (PMNs), which produce potent anti - 2 microbial compounds. As well as providing the energy for metabolic reactions and hence infection defence mechanisms, oxygen also plays a major role in determining the oxidation - reduction potential of tissues. Bakker (1998) identifies that a low redox potential favours the growth of anaerobic bacteria. Bowler et al (2001) state that a low redox potential will facilitate the development of synergistic aerobic/anaerobic populations.

Wounds often have a diverse array of microflora. The primary pathogens involved in the infection of chronic and acute wounds are thought to be Staphylococcus Duress, Pseudomonas aeruginosa and beta-hemolytic streptococci. These pathogens are aerobic or facultative. However, anaerobic pathogens are often overlooked in wound infection investigations, because they reside deep within the dermal tissue. Anaerobic micro-organism isolation, identification and collection is time consuming and labour intensive. Bowler et al (2001) investigated and conclude that there is correlation between the incidence of anaerobic pathogens and the prevalence of infection.

Bascom (1996) reports that anaerobic bacteria are the true causative micro-organisms of wound infection and that improved oxygenation of wounds is required to minimise infection.

The polymicrobial nature of wounds has been widely published, however Staphylococcus Duress is considered to be the most problematic bacterium in traumatic, surgical and burn wound - 3 - infections (Bowler et al, 2001). Tengrove et al (1996) report that when four or more bacterial groups are present within a leg ulcer, the likelihood of healing is significantly reduced. This finding promotes the hypothesis that microbial synergy occurs within wounds increasing the net pathogenic effect and severity of the infection. Oxygen consumption by aerobic bacteria induces tissue hypoxia and lowers the redox potential, which provides a more favourable habitat for anaerobic organisms. Nutrients produced by one micro-organism may encourage the growth of potentially pathogenic co-habiting micro- organisms. Some anaerobes are able to impair host immune cell function and hence provide an advantage for themselves and other co- habiting micro-organisms. Bowler (2002) states that micro-organisms are able to aid each other within a wound. Micro-organisms (especially in biofilms) use a communication mechanism called Quorum sensing.

This is a cell density dependent form of communication, facilitating survival in a new harsh environment. They release signalling molecules informing each other of "survival tips" (i.e. produce a specific morphological change or a specific defensive chemical).

Debridement is an integral part of wound healing. The removal of dead and unhealthy tissue is essential to minimise the habitat available for microbial colonization and allow new tissue formation. Debridement is achieved through physical removal of tissue using a sharp instrument or the application of saline or sterile water. The management of bite wounds involves high pressure irrigation to reduce microbial load.

Historically ozone has been used to disinfect wounds in its gaseous form or dissolved within oil. Direct ozone gas application, intravenous injection, rectal insufflation or autohemo-ozonotherapy are all patented methods of medical ozone application. Patent examples include RU-2178699, FR-2784388, US-6073627.

Aqueous Ozone Hypotheses 1. Disinfection 1.1.0zone is highly reactive and decomposes through the formation of free radicals to form molecular oxygen. Free radicals have an unpaired electron in their outer orbital making them highly unstable and reactive. These free radicals comprise hydroxyl, superoxide or ozonide radicals. Ozone micro-organism attack is primarily on the cellular membrane, with damage subsequently occurring to other cell sites. The proposed mechanism of action is thought, in large part, to relate to the olefinic bonds within the micro-organism cell membrane being attacked by ozone to form an ozonide or other decomposition product. The ozonide reacts with enzymes, sulfhydryl groups and aldehydes, releasing peroxyl compounds. The peroxyl compounds further damage proteins, DNA and other structures. The cell is Iysed and the cytoplasm dispersed. - 5 -

In essence, the aqueous ozone would be used to reduce the microbiological organisms within the wound.

1.2. Aqueous ozone will be particularly effective against anaerobic bacteria due to their lack of anti-oxidants and other oxidation defence systems. Aerobic bacteria produce anti-oxidants such as Superoxide Dismutase to prevent cellular damage caused through respiration using oxygen. Anaerobic bacteria do not use oxygen to respire and hence have not evolved advanced anti-oxidants. The removal of anaerobic bacteria will reduce the likelihood of infection (Bowler, 2002).

1.3. Free radical based oxidation is random and hence it will be extremely difficult for a micro-organism to develop resistance to aqueous ozone. Free radical based disinfection does not involve target site specificity. Free radicals will be effective against all micro-organisms, with the killing rate being dependent on, among other things, the prevalence of anti-oxidants within different microbial species.

1.4. A sufficiently long contact period will remove all micro- organisms from a wound bed, creating a sterile environment.

2. Debridement 2.1. Aqueous ozone is not cell specific and will attack the wound tissue as well as the micro-organisms. Unhealthy or dead tissue is less well perfused than healthy tissue and as such does not contain as much anti- oxidant or enzymatic agents (Superoxide Dismutase, glutathione, macrophage, etc). The unhealthy tissues will mount a far weaker defence against the free radical attack than the healthy tissues and hence will be more prone to damage/rupture/removal than healthy tissues. Hence, the aqueous ozone will provide a quasi-selective chemical debridement system, creating an improved healing environment.

3. Moist healing environment 3.1. The application of aqueous ozone will provide a moist healing environment (in conjunction with 1.4.). A moist healing environment is critical to wound healing (Winter, 1962).

4. Reactive Oxygen Species (ROS) 4.1. Aqueous ozone produces reactive oxygen species as decomposition intermediaries. The ROS produced will complement the bodies own natural defence system in which Polymorphonucleocytes (PMNs) produce ROS to remove micro- organisms. The aqueous ozone healing system is biomimetic, - 7 - providing a "booster" when the bodies own PMNs have been overwhelmed by infection.

4.2. Aqueous ozone will act as an ROS generator in poorly perfused ischemic tissues. The lack of perfusion inhibits the body's own production of ROS through a deficiency in nutrient/oxygen/energy.

The aqueous ozone artificially creates the body's natural infection removal mechanism.

4.3. ROS will support the formation of blood vessels (angiogenesis) and stimulate collagen production (Sen et al, 2002).

4.4. Micro-organisms communicate through quorum sensing, which is facilitated through the release of signalling molecules. ROS may actively oxidise these signalling molecules reducing synergistic survival effects. This mechanism would be important in reducing any biofilm formation.

5. Oxygenation 5.1. Aqueous ozone decomposes to water and oxygen. The decomposition reaction takes place within the wound providing surface application of oxygen to cells and produces a hyperopic environment. Anaerobic bacteria cannot survive in a hyperoxic environment, reducing infection. - 8-

5.2. A hyperopic environment produced through aqueous ozone application can provide a source of oxygen to poorly perfused tissues (ischemic), which may improve wound healing.

5.3. Cytokines and growth factors show an improved mechanistic action in a hyperopic environment, which can be facilitated through the use of aqueous ozone application equipment.

5.4. The aqueous ozone application equipment contains an oxygen concentrator that can be used to provide high pressure sterile oxygen to a wound. Oxygen is critical to the wound healing process. The equipment allows the application of oxygen to the wound via a high pressure jet or through the use of a hyperbaric chamber around the wound area.

6. Acute wound response 6.1. Research has identified that inflicting an acute wound within a chronic wound can induce a wound healing response. The cellular oxidation caused by aqueous ozone application may induce an acute wound type response within a non-healing chronic wound. - 9 -

Ozonated water Ozonated water is widely used to kill bacteria and other micro- organisms. However, when generating and dissolving ozone in water it is usual to expect levels of under 1 ppm. The method of the invention produces a high concentration ozone solution capable of rapid disinfection.

This invention relates to the use of high concentration aqueous ozone solution to disinfect surfaces and more specifically wounds of both humans and animals. The process and application of the method is novel, although the technology is relevant to many pieces of equipment and apparatus.

W0-0020343 discloses an apparatus for producing an aqueous ozone solution to disinfect animal house feed water. Although similar to the apparatus of this invention, the process requires pressurization of the contactor to facilitate ozonation. This invention requires no such pressurization.

US-5834031 discloses an apparatus that utilises aqueous ozone to treat foot fungi. This unit uses a single "in-line" ozonation process to produce aqueous ozone, whilst completely submerging the appendage to be treated. Our system utilises a contactor and closed loop system - 10 - to produce high concentration aqueous ozone solution. The solution is also applied via a spray as opposed to a submersion.

US-5098415 discloses an apparatus to treat foot diseases using aqueous ozone. The system utilises submersion of the appendage into aqueous ozone solution.

WO-0172432 discloses a mobile spray apparatus for providing an aqueous ozone stream. The aqueous ozone production process uses an "in-line" method of production as well as a de-gas unit. Our invention utilises a "closed loop" system incorporating a contactor.

US-6455017 discloses a mobile apparatus for washdown and sanitising using aqueous ozone. The aqueous ozone production process uses an "in-line" method of production. Our invention utilises a "closed loop" system to facilitate high concentration ozone production.

US-2002139755 discloses a method for enhancing dissolution of gasses in liquids. The method uses a plurality of nozzles sized and sited to produce micro-fine bubbles and initiate rotational flow. Our invention incorporates a single straight nozzle used to facilitate an increase in back pressure required by the injector. The nozzle is not sized to produce micro-fine bubbles.

- 1 1 - RU-2175539 discloses a method of treating wounds with ozone gas.

The unit is designed and functions in a manner significantly different from that of our invention. The system is based upon the application of gas as opposed to a concentrated aqueous solution.

US-4375812 discloses a method for treating burn injuries with aqueous ozone. The invention relates to submerging the patients entire body in a bath of aqueous ozone.

The invention provides a method of disinfecting surfaces with particular reference to wounds. Although described in the context of a wound surface, the scope of the invention covers all types of surfaces.

The method comprises the steps of causing aqueous ozone to flow over and into a wound surface at a pre-determined concentration and rate, whilst actively removing ozone gas released by the application of the solution to the wound surface. The invention incorporates a method of collecting the solution after it has been applied. Thus the aqueous ozone solution disinfects surfaces and promotes healing within wounds due to the issues described in the background to the invention.

The system is novel and inventive, as it takes a number of previously invented systems (ozone generator, oxygen concentrator, differential pressure injector) and combines them in such a way as to produce a - 12 portable and highly mobile unit that is able to produce very high aqueous ozone concentrations (>20ppm).

Previous aqueous ozone based disinfection systems have been based on large less-portable systems or on mobile systems that can only produce low concentration aqueous ozone solutions (5ppm). The concept of applying ozone to wounds is not novel, however the theories developed based on the inventors research and understanding of biological systems and their modes of interaction with aqueous ozone is novel. The development of an effective system to apply high concentration aqueous ozone to a human (or animal) without endangering the patient through exposure to ozone gas is novel and inventive. The invention incorporates an aqueous ozone delivery system that delivers the high concentration solution to the wound surface whilst minimising the amount of ozone gas released from that solution. The design of the spray configuration, the pressure requirements and the spray head enclosure design are all novel in regard to minimising ozone gas release. The use of an extraction system to remove ozone gas from the wound area is novel, as is the design, which incorporates the aqueous ozone delivery conduit and ozone gas extract into a single pipe system.

The catchment tray also incorporates areas of novel and inventive design. The perforated insert tray is designed to allow aqueous ozone solution to pass through to the bottom of the tray. Ozone gas is heavier than air and hence will remain at the bottom of the tray. The insert functions to trap the ozone gas in the bottom of the tray away from the patient. The method of removing the waste solution within the tray is based on a peristaltic pump system, therefore removing the ozone gas as well as the waste solution. The invention has been designed so that all sources of ozone gas are extracted back to a single manifold at the input to the systems main fan, which forces the gas through a catalytic destruct. The design of the system is novel and inventive in that a single catalyst is used to destruct gas from three individual sources. Further, the catalytically reacted gas is directed to and exhausted over the surface of the ozone generator, which is preferentially an air-cooled (as opposed to watercooled) generator.

The primary catalytic destruct is novel and inventive. Catalytic destructs are designed to operate with dry gas supplies, as water poisons most catalysts. The design of the system allows the catalyst to destroy wet ozone gas, without damaging the catalyst.

The invention allows the user to determine the concentration of the solution that is to be applied to the surface (preferentially ranging from 1 - 21 ppm). The user is able to select the aqueous ozone concentration required at the start of the cycle. The user is also able to select the duration for which the solution is to be applied to the surface. Both of these factors add novelty and "uniqueness" to the - 14 The following is a description of some specific embodiments of the invention, reference being made to the accompanying drawings in which: Figure 1 is a diagrammatic illustration of a system for generating and applying ozonated water to a pound; and Figures 2 and 3 show modification of the system.

Vessel 17 contains a volume of water. Fan 28 is activated drawing air through a suction head 25 and a tube 26. A heating element 16 is activated heating an ozone destruct unit 15. A temperature sensor 1 6a is linked back into a programmable logic computer (PLC), which controls the heating process and maintains the destruct unit 15 at a constant temperature between 40 and 80 C, but preferentially 60 C. A pump 18 is activated and a solenoid valve 19 opened. Water is transferred into a contactor 7a until a sufficient level is reached to activate a level sensor 11. A relay is activated sending a signal back to the PLC, which turns off a pump 18 and closes a solenoid valve 19. A pump 7 is activated taking in water through an inlet 9, circulating through a differential pressure injector 6 (such as a Mazzei injector Pat No. US-5863128) and returning it to the contactor 7a via a nozzle inlet 8. The nozzle serves two functions. Primarily it provides the back pressure required by the differential injector and secondly, it increases the gas/liquid mixing within the contactor. An oxygen supply 1, - 15 preferentially using an oxygen concentrator, supplies dry oxygen gas through a throttle valve 2, a pressure regulator 3 to an ozone generator 4. The ozone generator can utilise ultra violet, proton exchange membrane or corona discharge based production methods, but preferentially is an air cooled corona based ozone generator. The ozone generator is activated and a solenoid valve 5 is opened. Ozone is drawn through the differential pressure injector where it contacts the water. The gas/liquid mixture stream is forced through a nozzle 8 and into the contactor 7a. Ozone gas bubbles move up through the contactor and exit at an outlet 1 3a into a pipe 14. The pipe 14 is angled so that any condensation that occurs within the pipe runs back down through outlet 1 3a back into the contactor 7a. The ozone gas passes through the destruct 15, where it is broken down into oxygen.

The destruct 15 is heated, which prevents moisture forming within the destruct itself, causes condensation to occur in pipe 14 and aids in the ozone decomposition process. The oxygen gas exits destruct 15 and moves into manifold 27. The oxygen gas is drawn through fan 28 and into a secondary ozone destruct 29. The oxygen gas exits the secondary ozone destruct where the air stream is directed onto the ozone generator 4 where it aids in cooling the unit.

Returning to the ozonation process in the contactor. Inlet 9 is shaped to prevent ozone gas bubbles being sucked into the re-circulation system. The aqueous ozone concentration is monitored by a dissolved ozone sensor 13 linked into the PLC. When the dissolved ozone - 16 concentration reaches the desired level, set by the operator, the PLC switches off the oxygen concentrator and the ozone generator and closes a solenoid 5. A pump 7 is switched off and a pump 20 activated. A solenoid valve 21 is opened and the solution moves along the pipe where the pressure is restricted to between 40 and 100 mbar, but preferentially 70 mbar, by a pressure and flow regulator 22. The aqueous ozone solution moves through a pipe 23, which itself is contained within another pipe 26, which is preferentially flexible. The aqueous ozone exits the pipe 26 via a spray head 24. The spray is designed and constructed so as to produce a series of jets, preferentially in an interlocking fan configuration.

The spray system although appearing simple is actually quite complicated. When high concentration ozone solution is forced through an aperture a pressure differential is created and causes the ozone gas dissolved in the stream to come out of solution into the atmosphere (due to ozone's vapour pressure). The higher the pressure differential the greater the amount of gas liberated to atmosphere. The legal atmospheric limit for ozone is 0.1 ppm, which is very low. Hence the spray head has been developed to use "jet holes" that are sufficiently small to use low quantities of solution (facilitating the small size of the unit) and yet have a large enough diameter to prevent an excessively high pressure differential being created that liberates too much ozone gas from the solution. The pressure at which the ozone solution is supplied to the head is also a - 17 factor and tests have indicated that a level around 70 mbar is the most suitable. Higher pressures mean more ozone gas is liberated to atmosphere and also causes the jets to be too powerful "drilling" bugs down into the surface of the wound.

As the solution exits the spray head, the pressure drop causes ozone gas to come out of solution. The overlapping arrangement of the jets minimises the surface to volume area of the outer edges of the spray cone, thus reducing the amount of ozone gas that is liberated from the solution. Ozone will rapidly decompose in air and hence the reduced surface to volume ratio is critical in preventing the decomposition of the ozone solution as it is travailing from the spray head to the wounds surface. The jets operate at very low pressures to minimise the amount of ozone gas that escapes from solution and also to ensure that micro- organisms are not driven down into the wound bed.

The spray head is located within a head attachment (further referred to as the "cone head") 25, shaped to match the dimensions of the "jet cone" produced by the spray head. The length of the cone head is dependent upon the pressure of the jets, but is preferentially 1 25mm.

The inside of the cone head is at a negative pressure to the atmosphere due to its connection to fan 28, via flexible tube 26. Any ozone gas released from solution in the spraying process is sucked back through tube 26 and subsequently passed through the secondary ozone destruct 29, where it is decomposed to oxygen. The cone head is positioned over the wound to be decontaminated/healed. The distance from the wound surface to the edge of the cone head is dependent on the pressure of the jets but is preferentially 1 Omm.

The patient whose wound is to be disinfected/healed can be bed- ridden or mobile. A collection tray 32 is placed under the patients appendage on which the wound is located. The catchment tray contains a jointed support mechanism that takes the weight of the patients appendage during the treatment. The support mechanism can be rigid or flexible, but preferentially comprises of a removable padded concave or convex support, located upon a knuckle joint to facilitate horizontal rotation. This in turn is located on a stem fixed to the collection device by means of a joint that allows the stem to move in an arc in the vertical plane. Preferentially this is a pin joint. The catchment tray has a removable insert that has holes in it to allow the used solution to drain to the base of the tray. This insert will preferentially be a perforated sheet of a configuration that allows the solution to drain through, but retains any large biological material flushed off the wound in the disinfection process. The catchment tray has side flanges upon which the spray head system is mounted. The spray head is fixed to a mounting and support device that securely holds the spray cone in position above the wound. This mounting device can comprise of a wide range of structures to retain the head in its required position, but is preferentially an electromagnetic base attached to a flexi-rigid conduit upon which the spray head is clamped. The base of the catchment tray contains a number of holes - 19 - through which the used solution is drawn out of the tray. A pump 35 creates a negative pressure within vessel 34, causing the liquid in the collection tray to be drawn into the vessel 34. The gas removed from vessel 34 by pump 35 is directed through manifold 27, where it passes through the secondary catalyst. Any residual ozone gas released by the used solution is decomposed here.

The solution is applied to the wound for a period of time determined by the operator and programmed into the PLC at the start of the I treatment. Once the required duration has past, the PLC closes valve 21 and continues to operate fan 28 and pump 35 for a defined period! of time to clear the catchment tray of solution. During this period valve I 36 is opened and the solution within the contactor is pumped into vessel 34, until level switch 12 is activated. Pump 20 is turned off and valve 36 is closed. After this period has passed the pump 35 and fan 28 are switched off.

The inlets and outlets of vessels 17 and 34 comprise of quick connect couplings to facilitate their ease of removal and attachment. At the I end of the treatment, vessel 34 is disconnected and the water I contained within it poured straight to drain.

Figure 2 shows an alternative arrangement of the apparatus, whereby vessel 17 and pump 18 are replaced by a direct pipe connection to a mains water supply via a pressure restriction valve. -

Figure 3 shows an alternative arrangement of the apparatus, whereby vessel 34 is removed and the contents of the catchment tray are pumped directly to drain via a pump. The excess solution remaining in the contactor is pumped directly to drain as opposed to vessel 34.

This solution can pass through a carbon filter within the waste pipe line to destroy any ozone that may remain.

The system is described operating with tap water taken from a domestic or commercial supply. The invention does not preclude the use of a filtered or conditioned water supply. Such a water supply will have an effect of speeding up the ozonation process, but is not the preferred water supply of use due to the reduction in portability filtration systems present. 21

Claims

Claims 1. An apparatus for disinfecting surfaces, but more specifically

the disinfecting and healing of human and animal wounds, the apparatus comprising: a) a reaction vessel having b) one or more inlets for the fluid being treated in the reaction vessel; c) one or more outlets for the fluid being treated in the reaction vessel; d) an outlet for gas to be removed from the reaction vessel; e) a re-circulation loop suitable for carrying a gas/liquid mixture having: outlets connected to the reaction vessel at one end and an inlet connected to the reaction vessel at its other end; a means for dissolving gas into the fluid within the loop; a means for moving fluid around the piping loop; and means for preventing gas bubbles within the reaction vessel entering the re- circulation loop; f) means for measuring the dissolved ozone concentration and, or, the oxidation reduction potential of the fluid; and 9) means for applying said fluid contained within the reaction vessel to a surface, preferentially a wound h) means of containing and collecting said fluid once it has been applied to the surface.

- 22 -
2. The apparatus of claim 1, where the means of applying a gas into the fluid within the loop is a differential pressure injector.
3. The apparatus of claim 1 or claim 2, where the apparatus is suitable for the use with ozone.
4. The apparatus of any of claims 1 to 3, where the fluid enters and exits the reaction vessel through the same orifice.
5. The apparatus of any of claims 1 to 4, where the undissolved gas is captured and passed through a destruct device.
6. The apparatus of any of claims 1 to 5, where the reaction fluid produced is aqueous ozone.
7. The apparatus of any of claims 1 to 6, where the reaction fluid is applied to the surface by means of a spray head.
8. The apparatus of any of claims 1 to 7, where the reaction fluid is sprayed onto a surface while encompassed by a negative pressure atmosphere.

- 23 -
9. The apparatus of any of claims 1 to 8, where the reaction fluid is sprayed onto a wound and is subsequently collected in a device, onto or into which the patients' appendage is placed.
10. The apparatus of any of claims 1 to 9, wherein the equipment is portable.
11. A process for destroying the undissolved gas released from the reaction vessel, comprising of: a) A gas decomposition unit b) A heating element c) A temperature sensor
12. The apparatus in claim 1 1, where the destruct unit is a manganese dioxide catalyst
13. The apparatus in claim 11, where the gas decomposition unit destroys ozone gas.
14. The apparatus in claim 1 1, where the gas decomposition unit is connected to the reaction vessel by a horizontally angled tube.
15. The apparatus in claim 11, where heating element and temperature sensor keep the gas decomposition unit at a - 24 temperature of between 40 and 80 C, although preferentially 60 C.
16. The apparatus in claim 1 1, where the decomposed gas is directed through a secondary destruct unit.
17. The apparatus in claim 16, where the secondary destruct unit is an activated carbon catalyst.
18. An apparatus for applying the fluid produced within the reactor to a surface and more preferentially a wound, comprising: a) A means of conducting the fluid from the reactor to the surface.

b) A spray head c) A shroud d) A means of producing a negative pressure around the spray head.
19. The apparatus in claim 18, where the conduit is a tube resistant to ozone.
20. The apparatus in claim 18, where a pump moves the fluid along the conduit. - 25
21. The apparatus in claim 1 8, where the spray head consists of a number of orifices to produce fluid jets
22. The apparatus in claim 18, where the spray head consists of a number of jets that are located to produce an overlapping pattern
23. The apparatus in claim 18, where the spray head contains a number of orifices between 0.2mm and 1.5mm in diameter, but are preferentially 0. 5mm.
24. The apparatus in claim 18, where the fluid is directed to the spray head at a pressure of between 50 and 1 OOmbar, but preferentially 70 mbar.
25. The apparatus in claim 18, where the spray head is mounted on a framework located in the opening of one end of a tube, wherein the other end is connected to a suction device.
26. The apparatus in claim 18, where the shroud has an open end and is pyramidal in shape.
27. The apparatus in claim 18, where the dimensions of the shroud are such as to closely contain, yet not interfere with, the fluid spray pattern. 26
28. The apparatus in claim 18, where the spray head is held in place by a support structure.
29. The apparatus in claim 28, where the support structure consists of a switchable electromagnetic base and a variable position clamping device.
30. An apparatus for collecting the fluid once it has been applied to a wound, comprising: a) a catchment device b) a means of conducting the fluid from the catchment device to the main unit.

c) a means of conducting ozone gas from the catchment device to the main unit.
31. An apparatus for producing a spray of ozonated water for disinfecting a surface comprising a reservoir for accumulating ozonated water, means to deliver ozonated water from the reservoir to a nozzle having one or more jets for delivering a spray of ozonated water onto the surface to be treated, means to circulate a flow of water from the reservoir through an ozonating station and to the reservoir, means to supply ozone to the ozonating station to be entrained in the flow of circulating liquid returning to the reservoir to enable the ozone - 27 concentration in the water to be raised to a requisite level prior to delivery of the ozonated water to the spray nozzle for application to the surface to be treated.
32. An apparatus as claimed in claim 31 wherein the circulation means has an inlet in the reservoir which is upwardly open to minimise entry of bubbles of ozone into the inlet.
33. An apparatus as claimed in claim 31 or claim 32, wherein the ozonating station comprises a venture through which the water in the circuit passes and to the constriction of which the ozone gas is supplied to be entrained in the water flow.
34. An apparatus as claimed in any of claims 31 to 33, wherein the nozzle is arranged to deliver jets of ozonated water with a low pressure drop across the nozzle to minimise release of ozone from the aqueous solution.
35. An apparatus as claimed in any of the claims 31 to 34 wherein the nozzle has an encircling shroud and means are provided for withdrawing ozone gas liberated at the nozzle from around the nozzle for destruction.