GB2593944A

GB2593944A - Disinfection method and apparatus

Info

Publication number: GB2593944A
Application number: GB2009092.4A
Authority: GB
Inventors: Herd Matt; Jones Ross; Starkie Joanna; Hember Miles; Amos Dall
Original assignee: Sagentia Ltd
Current assignee: Sagentia Ltd
Priority date: 2020-04-08
Filing date: 2020-06-15
Publication date: 2021-10-13
Also published as: GB202005247D0; GB202009092D0

Abstract

A disinfection system 100 comprising: a sealable housing comprising treatment space 106; a means for circulating air 104; wherein the means for circulating air 104 can drive an air flow along a supply flow path and a return flow path; and a heating element 124 situated on the air flow path to heat the air. The supply and return air flow paths may be separated by a partition. Also claimed is a disinfection system (Fig.2, 200) comprising: a treatment module (Fig.2, 202) comprising a treatment space (Fig.2, 206); a separate air circulation module 104; a means for connecting the treatment and air circulation modules together; wherein upon connection, an air flow path is provided between the treatment 202 and air circulation modules 104; and a further heating element (Fig.2, 224) to heat the circulated air. There may also be more than one treatment module. The time and temperature of treatment may be adjustable depending on the pathogen and/or item to be disinfected. Also claimed is a similar disinfection system, further comprising a fan 152 in an air circulation module 104. Also claimed is a method of disinfecting an item.

Description

DISINFECTION METHOD AND APPARATUS

Field of Invention

This invention relates to a disinfection apparatus and method. More specifically, the invention relates to a disinfection apparatus and method for circulating heated air through a treatment chamber, and a modular disinfection system for providing scalability.

Backqround Presently, disinfection of personal protective equipment (PPE) or other medical equipment, used in hospitals or by community health workers, is carried out at centralised facilities. All potentially infected equipment requiring disinfection is brought to the central facility where steam cleaning is carried out, often using machinery such as autoclaves.

This practice is problematic. Centralised cleaning requires many people and objects to interact at a single location which can have the effect of aiding the transmission of viruses and other pathogens. For community health workers, it is inefficient and inconvenient to visit a central location to have equipment disinfected between every visit to a patient. In less developed countries, it is difficult to transport large machines (such as autoclaves) to remote locations, if such expensive machinery is available at all. In all cases, the requirement with steam cleaning for consumables, such as a water supply and often a supply of a chemical disinfectant, complicates efforts to provide localised cleaning facilities.

Summary of the Invention

Aspects and embodiments of the present invention are set out in the appended claims.

These and other aspects and embodiments of the invention are also described herein.

According to one aspect of the present invention, there is provided a disinfection system comprising: a sealable housing comprising a treatment space for receiving items to be disinfected; means for circulating air; and a heating element; wherein the means for circulating air is arranged to drive a flow of air within the disinfection system along an air flow path comprising: a supply flow path from the means for circulating air to the treatment space; and a return flow path from the treatment space to the means for circulating air; wherein the heating element is situated on the air flow path and is arranged to heat air driven along the air flow path. -2 -

Preferably, the system further comprises an air return plenum situated on the return flow path. Preferably, the means for circulating air is arranged to extract air from the air return plenum. Preferably, the system further comprises an air flow regulating element situated along the return flow path between the treatment space and the air return plenum.

Preferably, the system further comprises an air supply plenum situated along the supply flow path. Preferably, the means for circulating air is arranged to output air into the air supply plenum. Preferably, the system further comprises an air dispersion element situated along the supply flow path between the air supply plenum and the treatment space.

Preferably, the system further comprises a partition for separating the supply flow path and the return flow path.

Preferably, the treatment space, the means for circulating air, the heating element, and the air flow path are contained within the sealable housing to form a closed air circulation system.

According to another aspect of the present invention, there is provided a disinfection system comprising: a treatment module comprising a treatment space for receiving items to be disinfected; an air circulation module comprising means for circulating air; and means for connecting the treatment module and the air circulation module, wherein, upon connection of the treatment module to the air circulation module, an air flow path is provided between the treatment module and the air circulation module; the system further comprising a heating element arranged to heat air circulated by the means for circulating air.

Preferably, the treatment module further comprises means for connecting to one or more further treatment modules.

Preferably the system comprises at least one further treatment module, comprising a treatment space, connected to the first treatment module, wherein, upon connection of the further treatment module to the first treatment module, an air flow path is provided between the at least one further treatment module and the air circulation module.

Preferably, the system comprises an air supply plenum shared across the treatment modules and situated on a supply flow path between the circulation module and the treatment spaces of the treatment modules. Preferably, the system comprises a resistive element shared across the treatment modules and situated on the supply flow path between the shared air supply plenum and the treatment spaces of the treatment modules. -3 -

Preferably, the system comprises an air return plenum shared across the treatment modules and situated on a return flow path between the treatment spaces of the treatment modules and the air circulation module. Preferably, the system comprises a resistive element shared across the treatment modules and situated on the return flow path between the treatment spaces of the multiple treatment modules and the shared air return plenum.

Preferably, the treatment module(s), the air circulation module, and the air flow path form a closed air circulation system.

Preferably, the treatment module(s) is/are expandable and collapsible, thereby to vary the volume of the treatment space(s).

Preferably, the treatment module comprises a double-walled exterior surrounding the treatment space.

Preferably, the system comprises an insulating material arranged to prevent heat loss from the treatment module.

Preferably, the system comprises means for sealing the treatment chamber(s) while an item is being disinfected.

Preferably, the system comprises at least one temperature sensor for measuring the temperature within the treatment chamber(s).

Preferably, the system comprises means for receiving user input to select a temperature and/or time period setting for a disinfection cycle.

Preferably, the system comprises means for controlling the operation of the means for circulating air and the heating element in dependence on the sensor measurements and the user input.

Preferably, the system comprises a timer configured to count the time for which the temperature within the treatment chamber(s) is at or above the user selected temperature.

Preferably, the system comprises means for unsealing the treatment chamber(s) when treatment chamber has been at or above the a user selected temperature for a user selected time.

Preferably, the system comprises means for storing a temperature and/or time setting for a disinfection cycle. Preferably, the stored temperature and/or time setting corresponds to a particular pathogen and/or item to be disinfected. -4 -

Preferably, the system comprises means for providing information to the user, the information relating to: a temperature within the treatment chamber(s); the temperature of a surface of the system; and/or a length of time at which the temperature within the treatment chamber(s) has been at or above a temperature. Preferably, the means for providing information to a user comprises a display and/or a thermochroic indicator.

Preferably, the system comprises a support within the treatment chamber(s) for holding items to be disinfected in a spaced configuration. Preferably, the support is arranged to hold items in a spiral configuration.

Preferably, the system comprises an air filter arranged to filter air circulated by the means for circulating air.

Preferably, the system comprises means for connecting the system to an automobile auxiliary power outlet.

Preferably, the means for circulating air and/or the heating element are repurposed from commodity hardware, preferably from a hairdryer or a fan oven.

According to another aspect of the present invention, there is provided a disinfection system as aforementioned, for use in disinfecting items potentially infected with SARS-CoV-2.

According to another aspect of the present invention, there is provided a disinfection system comprising: a sealable housing comprising a treatment space for receiving items to be disinfected; a fan having an air outlet and an air inlet; an air supply flow path between the air outlet and the treatment space for supply of air from the fan to the treatment space; an air return flow path between the treatment space and the air inlet for return of air from the treatment space to the fan and a heating element for heating air within the system.

According to another aspect of the present invention, there is provided a disinfection system comprising: a treatment module comprising a treatment space for receiving items to be disinfected; and an air circulation module comprising a fan for circulating air within the system; wherein the treatment module and the air circulation module are attachable to and detachable from one another, and; wherein, upon attachment of the treatment module to the air circulation module, an air flow path is provided between the treatment module and the air circulation module.

According to another aspect of the present invention, there is provided a method of disinfecting an item, comprising: circulating air along an air flow path, the air flow path comprising a supply flow path and a return flow path, the circulating comprising: supplying, -5 -along the supply flow path, air from a means for circulating air to a treatment space within which the item is located; returning, along the return flow path, air from the treatment chamber to the means for circulating air; and heating the air circulating along the air flow path.

As used herein the term 'disinfect' and related terms, means to inactivate pathogens, such as viruses, present on an item so as to reduce the overall number of pathogens on the item. Items are referred to as 'infected' or 'potentially infected' if they have, or might have, such pathogens present on them.

Any apparatus feature as described herein may also be provided as a method feature, and vice versa. As used herein, means plus function features may be expressed alternatively in terms of their corresponding structure.

Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. In particular, method aspects may be applied to apparatus aspects, and vice versa. Furthermore, any, some and/or all features in one aspect can be applied to any, some and/or all features in any other aspect, in any appropriate combination.

It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and/or supplied and/or used independently.

The invention extends to methods, system and apparatus substantially as herein described and/or as illustrated with reference to the accompanying figures.

One or more embodiments will now be described, by way of example only and with reference to the accompanying drawings having like-reference numerals, in which: Figure 1 is a cross-sectional view of a first disinfection system with one treatment module and one circulation module; Figure 2 is a cross-sectional view of the first disinfection system with multiple interconnected treatment modules; Figure 3 is a block diagram showing the operation of the first disinfection system; Figures 4a and 4b are perspective views, and Figure 4c is a plan view, of a base module of a second disinfection system; Figure 5 is a perspective view of the second disinfection system showing the base module and an extension module; -6 -Figure 6 is cross-sectional view of the second disinfection system with base module and extension module; Figures 7a to 7d are perspective views of the second disinfection system in use; Figure 8 is a perspective view of a third disinfection system; and Figure 9 is a perspective view of a fourth disinfection system.

Detailed description

Figure 1 is a cross-sectional view of a first embodiment of the disinfection system 100. The disinfection system 100 is a modular, scalable system shown in Figure 1 having one treatment module 102 and one circulation module 104. The treatment module 102 has a treatment chamber 106 between an air supply plenum 108 and an air return plenum 110.

The air supply plenum 108 has an outer wall 112 corresponding in shape to the lower edge of an outer wall 114 of the treatment chamber 106. The air supply plenum 108 is secured to the treatment chamber 106 so that the outer wall 114 of the treatment chamber 106 continues from the outer wall 112 of the air supply plenum 108 at the joint (or junction) between the air supply plenum and the treatment chamber. The air return plenum 110 has an outer wall 116 corresponding in shape to an upper edge of the outer wall 114 of the treatment chamber 106. The air return plenum 110 is secured to the treatment chamber 106 so that the outer wall 116 of the air return plenum 110 continues from the outer wall 114 of the treatment chamber 106 at the joint between the treatment chamber and the air return plenum. To simplify manufacture of the disinfection system 100, the air supply plenum 108 and the air return plenum 110 are structurally identical but are secured to the treatment chamber 106 in opposite orientations. The walls 112, 114, 116 and other components which form the exterior of the system are heat insulating so as to prevent heat from within the treatment module 102 being transferred outside the module 102. For example, the walls 112, 114, 116 could be made from or comprise heat insulating materials (such as polystyrene foam). Additionally or alternatively, the walls 112, 114, 116 could have a double-walled structure with an inner and outer wall and an air gap, a near-vacuum, or a layer of insulating material (such as polystyrene foam) between the inner and outer walls. Additionally, components within the interior of the system are made from materials that have a low thermal mass (or heat capacity) so as to minimise the heat energy required to bring the interior of the system up to temperature. Advantageously, the separation of the treatment module 102 and the circulation module 104 means that the configuration of either module could be changed without requiring the other module also to be changed. 7 -

A seal 118 is disposed at the joint between the outer wall 112 of the air supply plenum 108 and the outer wall 114 of the treatment chamber 106 and extends around the entire length of the joint. The air return plenum 110 is secured to the treatment chamber 106 via a hinged connection 120 located at one side of the joint between the air return plenum and the treatment chamber. On the opposite side of that joint, the air return plenum 110 is detachably secured to the treatment chamber 106 by an interlock 122. A seal (not shown) is disposed between the outer wall 114 of the treatment chamber 106 and the outer wall 116 of the air return plenum 110 and extends around the entire length of the joint between the treatment chamber and the air return plenum.

A first resistive element 124a is secured within the treatment module 102 between the air supply plenum 108 and the treatment chamber 106. The resistive element 124a comprises at least one porous but resistive barrier layer 126a, such as a fabric layer, which intersects a path from the interior of the air apply plenum 108 to the interior of the treatment chamber 106. In this example, the resistive element 124a has two resistive barrier layers 126a; a first layer secured across the area enclosed by the top of the walls 112 of the air supply plenum 108 and one secured across the area enclosed by the bottom of the walls 114 of the treatment chamber 106. A first air filter layer 128a is interposed or sandwiched between, and retained by, the two resistive barrier layers 126a. A second resistive element 124b is secured within the treatment module 102 between the treatment chamber 106 and the air return plenum 110. The resistive element 124b comprises at least one resistive barrier layer 126b which intersects a path from the interior of the treatment chamber 106 to the interior of the air return plenum 110. In this example, the resistive element 124b has two resistive barrier layers 126b; a first layer secured across the area enclosed by the top of the walls 114 of the treatment chamber 106 and one secured across the area enclosed by the bottom of the walls 116 of the air return plenum 110. A second air filter layer 128b is sandwiched between, and retained by, the two resistive barrier layers 126b.

The interior of the treatment chamber 108, enclosed by the walls 114 and the resistive elements 124a, 124b, accommodates a support 130, for example a rack, on which potentially infected personal protective equipment 132, for example masks, can be loaded for disinfection. Whilst the example of personal protective equipment is referred to throughout, it should be understood that the system is suitable for use with other potentially infected items such as medical instruments. At least one sensor is situated within the interior of the treatment chamber 108. In this example, two temperature sensors 134a, 134b are mounted at different positions within the treatment chamber. -8 -

The treatment module 102 is connected to the circulation module 104 by an air return duct 136 and an air supply duct 138. The air return duct 136 is received through an opening 140 in the wall 116 of the air return plenum 110 and the air supply duct 138 is received through an opening 142 in the wall 112 of the air supply plenum 108. The circulation module 104 has a housing 144 having a first opening 146 through which the air return duct 136 is received and a second opening 148 through which the air supply duct 138 is received. The housing 144 of the circulation module 104 encloses an air circulation volume 150 which accommodates a fan 152 and a heating element 154 which in this example is a conductive wire coil. The circulation module 104 also comprises a control unit 156. The control unit 156 includes user input interface 158 for receiving user input to control the operation of the disinfection system 100, a timer 160, and a display 162 capable of displaying information about the operation of the system 100 to the user, such as the temperature as measured by the sensors 134a, 134b or the time remaining on the timer 160.

The fan 152 provides means for circulating aft around the disinfection system 100 as shown by the arrows in Figure 1. The fan 152 drives air across the heating element 154 which heats the air before it is circulated throughout the system 100. The air supply duct 138 provides a channel through which air driven by fan 152, and heated by the heating element 154, is supplied to the treatment module 102. The heated air supplied through the air supply duct 138 is prevented from immediately passing into the treatment chamber 106 by the first resistive element 124a. The barrier layers 126a are porous but provide a degree of air resistance. The air supply plenum 108 thus acts to collect the heated air arriving through the air supply duct 138 before the air passes through the resistive element 124a into the treatment chamber 106. The heated air from the circulation module 104 therefore mixes together with other air present within the air supply plenum 108 to generate a body of air of approximately uniform temperature within the air supply plenum 108. The resistive element 124a also acts to disperse the air and thus regulate the rate of air flow from the air supply plenum 108 to the treatment chamber 106 across the area of the system by preventing uneven air currents from the circulation module 104 propagating into the treatment chamber 106. Therefore, the air that emerges through the resistive element 124a into the treatment chamber 106 has an approximately uniform flow rate and temperature across the area of the resistive element 124a. The first air filter layer 128a filters the heated air as it passes through the first resistive element 124a to remove some pathogens from the air. The first air filter layer 128a also provides a degree of air resistance.

The air passing from the air supply plenum 108 into the treatment chamber 106, through the resistive element 126a, is driven through the interior of the treatment chamber 106 towards the air return plenum 110. Heat from the air is transmitted to the personal protective -9 -equipment 132 held within the treatment chamber 106 thus heating the equipment 132 and thereby gradually disinfecting the equipment 132. The temperature sensors 134a, 134b measure the temperature of the air within the treatment chambers 106, in which case it is either assumed that the equipment 132 is at the same temperature as the air or a calibration is used to convert the measured air temperature to a temperature for the equipment 132.

Alternatively, the sensors are arranged to contact the equipment 132 within the chambers so as to directly measure the temperature of the equipment. The two temperature sensors 134a, 134b are located at different positions within the treatment chamber to measure air temperatures from different locations of the treatment chamber 106, to identify any non-uniformity in the temperature of the chamber and to enable an average temperature of the chamber to be calculated.

The air flowing through the treatment chamber 106 towards the air return plenum 110 is prevented from immediately passing into the air return plenum 110 by porous but air resistant barrier layers 126b of the second resistive element 124b. If the heated air within the treatment chamber 106 could flow freely in to the air return plenum 110, the air would tend to be quickly extracted from the treatment chamber 106 resulting in relatively ineffective heating of the equipment 132 within the chamber. In addition, the air would tend to be drawn towards the side of the treatment chamber 106 closest to where the air return duct 136 is located which would result in uneven heating of the equipment 132. The resistive element 124b causes the heated air to be retained within the treatment chamber 106 for longer so that it circulates about the chamber to facilitate more effecting heat transfer from the heated air to the personal protective equipment 132. The resistive element 124b also regulates the rate of air flow from the treatment chamber 106 to the air return plenum 110 across the area of the resistive element 124b by preventing immediate extraction of air from the treatment chamber 106, therefore ensuring a more uniform distribution of hot air within the treatment chamber 106 and thus more even heating of the equipment 132. The second air filter layer 128b filters the heated air as it passes through the second resistive element 124b to remove some pathogens from the air. The second air filter layer 128b also provides a degree of air resistance.

The air that passes from the treatment chamber 106 to the air return plenum 110, through the second resistive element 124b, is extracted through the air return duct 136 under the action of the fan 152. The air returns to the circulation module 104 where the fan 152 drives the air through the air circulation volume 150 towards the heating element 154 and on to circulate the air again through the disinfection system 100. The treatment module 102 and circulation module 104 of the disinfection system 100 together provide a closed system for recirculating a flow of hot air over the equipment being disinfected. This avoids blowing -10 -particles off the equipment and into the surrounding room, to reduce the risk of contamination of the outside room. Recirculation of hot air around the system also provides for a more stable air temperature within the system 100 as opposed to heating ambient air from outside the system. Recirculation of hot air around the system also results in more efficient heating of the air by reducing heat losses to the outside, which in turn reduces the power requirements for the fan 152 and the heating element 154. A lower power requirement enables the system to be powered by a wider variety of power sources and thus provides for increased convenience and portability. As the system 100 is closed On that air is prevented from escaping from the system 100, for example due to the walls 112, 114, 116, seal 118, and interlock 122) hot air is prevented from leaking into the outside environment and so the system 100 does not increase the heating, ventilation, or air-conditioning burden in the room in which the system 100 is located. This is particularly advantageous in hospitals where the air conditions is important. The use of hot (dry) air rather than steam means that the system 100 does not require any water supply or any other consumable.

This enables the system 100 to be used in locations where water is not available therefore increasing convenience and portability.

In use, a user accesses the interior of the treatment module 102 by unlocking the interlock 122 to unsecure the air return plenum 110 from the treatment chamber 106. The air return plenum 110 pivots about the hinged connection 120 when lifted by the user to unseal the treatment module 102 so that the interior of the treatment chamber 106 is accessible. The air return duct 136 is flexible to as to permit the air return plenum 110 to pivot. The user places potentially infected items, in particular personal protective equipment 132 such as masks, onto the support 130 provided within the treatment chamber 106. The equipment 132 may be secured to the support 130 so as to prevent the equipment 132 from being dislodged by the air flow during disinfection treatment. For example, a user may secure the elastic strap of a face mask to the support 130. The user then reseals the treatment module by closing the air return plenum 110 against the treatment chamber 106 and the interlock 122 secures the air return plenum 110 to the treatment chamber 106 to seal the space within the treatment module 102. The user then interacts with the control unit 156 to initiate a disinfection cycle. The user input interface 158 include a power control that enables the user to power up the circulation module 104 as well as controls for selecting the temperature to which the user wishes to heat the equipment 132. The user then selects on the timer 160 the desired length of the cycle.

The user input interface 158 includes a number of pre-set disinfection cycles stored in a memory of the control unit, each cycle operating at a particular temperature for a particular length of time that is suited to a certain type of equipment or a certain pathogen. For example, the control unit may store temperature and time settings for a disinfection cycle that is particularly suited to disinfecting an N95 face masks carrying the SARS-CoV-2 virus. In this example the temperature setting is 70°C and the time setting is 30 minutes, as these are conditions that will deactivate the virus but will not damage that mask. In addition, the user input interface 158 comprises means for receiving user input to create and store new disinfection cycle settings. For example, the user interface 158 may comprise buttons enabling a user to store a particular temperature and time setting as a pre-set in the memory of the control unit, for browsing the stored pre-sets and for selecting one of the stored presets from the memory. The system may also comprise means for downloading disinfection cycle pre-sets, for example from an external memory or via an internet connection, so that new disinfection cycle settings can be loaded onto the system.

The display 162 conveys information to the user about the treatment cycle, for example the real-time temperature inside the treatment chamber 106 as measured by the sensors 134a, 134b and the length of time remaining on the cycle. In addition, the system may become hot therefore a thermochromic indicator, such as a thermochromic strip or thermochromic ink, is preferably provided on the outside of the system to indicate to a user when it is safe (once the treatment cycle has ended) to touch the system to remove the disinfected items. The interlock 122 is controlled so as to seal the treatment module 102 during operation of the system so as to prevent access to the interior of the treatment module. The interlock 122 is controlled to unseal the treatment module 102 only when the treatment cycle is complete (that is, when the items within the treatment module have been exposed to the user selected temperature for the user selected period of time). This prevents an item being removed from the system before it has been properly disinfected. In addition, the interlock 122 may be controlled to unseal the treatment module after the treatment cycle is complete only when the interior of the treatment module has cooled to a safe temperature. This reduces the risk that a user would burns themselves when accessing the interior of the treatment module immediately after a treatment cycle has been completed. Additionally, the display 162 may display a measurement of the temperature within the treatment chamber to the user even after the treatment cycle is complete so that a user can see when the device has cooled to the point where it is safe to access the interior of the treatment chamber.

Critically, the treatment cycle conditions (the temperature and time) should be chosen so as to produce conditions within the treatment chamber that result in the inactivation of the pathogen that is, or potentially is, present on the equipment 132, but which do not result in destruction of the equipment 132 itself. For example, for disinfecting an N95 face mask (which uses a polypropylene electret layer) which is infected with the SARS-CoV-2 virus, the temperature should be set to 70°C and the timer should be set to 30 minutes. SARS-Cov-2 -12 -is inactivated if maintained at 70°C temperature for 30 minutes, whereas an N95 mask can be exposed to 70°C for at least 24 hours without becoming ineffective (because these conditions do not result in the deactivation of the charge-implanted filter materials in an N95 mask). The temperature limit at which electret filters begin to deactivate is about 95°C, therefore the disinfection system is configured so as not to exceed this temperature when used to disinfect face masks containing such filters.

During the treatment cycle, the fan 152 circulates air from the air circulation volume 150 across the heating element 154 (which, in use, is hot so as to heat the air passing across it) and into the treatment module 102 via the air supply duct 138. The heated air is collected in the air supply plenum 108 before passing through the first porous resistive element 124a (which acts as described above to homogenise and diffuse the air flow rate and temperature) and in to the treatment chamber 106 where heat is transferred from the air to the potentially infected equipment 132 thereby to heat the equipment 132. The air then flows across the second porous resistive element 124b and into the air return plenum 110 from which the air is extracted through the air return duct 136 under the action of the fan 152. The air is then recirculated as described. Once the cycle is complete, the interlock 122 is unlocked to unseal the treatment module 102 so that a user can access the interior of the treatment chamber 106 to remove the disinfected equipment 132.

Figure 2 is a cross-sectional view of the first embodiment of the disinfection system with multiple interconnected treatment modules. The disinfection system 200 in this example has been scaled up from the system 100 shown in Figure 1 by combining two further treatment modules together with the first treatment module described in Figure 1 to form one larger combined treatment unit 202. The disinfection system 200 also comprises a circulation module 104 of the same type shown in Figure 1. The treatment unit 202 thus comprises three treatment chambers 206a, 206b, 206c -one from each of the three treatment modules making up the treatment unit 202 -positioned between an air supply plenum 208 and an air return plenum 210. In this example, the first treatment chamber 206a contains one piece of personal protective equipment 132, the second chamber 206b contains no equipment, and the third chamber 206c contains two pieces of equipment 132. The treatment modules are connected in line to form the combined treatment unit 202 such that the walls of the treatment chambers form dividing walls 213a, 213b between the treatment chambers and outer walls 214a, 214b of the combined treatment unit 202. The air supply plenum 208 and air return 210 each span the area of the three treatment chambers 206a, 206b, 206c such that the three chambers share the same air supply plenum and air return plenum.

-13 -The air supply plenum 208 has an outer wall 212 corresponding in shape to the perimeter of the lower edge of the treatment unit 202. The air supply plenum 208 is secured to the treatment unit 202 so that the walls 214a, 216b of the end-most treatment chambers 106a, 106c continue from the outer wall 212 of the air supply plenum 208 at the joint between the air supply plenum and the treatment unit. The air return plenum 210 has an outer wall 216 corresponding in shape to the perimeter of the upper edge of the treatment unit 202. The air return plenum 210 is secured to the treatment unit 202 so that the outer wall 216 of the air return plenum 210 continues from the walls 214a, 216b of the end-most treatment chambers 106a, 106c at the joint between the treatment chamber and the air return plenum. To simplify manufacture of the disinfection system 100, the air supply plenum 208 and the air return plenum 210 are structurally identical but are secured to the treatment chamber 206 in opposite orientations. The internal and external walls of the treatment unit 202 and other components of the system are made from or comprise heat insulating materials (such as polystyrene foam) with a low thermal mass (or heat capacity) so as to prevent heat from escaping from the treatment chambers 206a, 206b, 206c and to minimise the heat energy required to bring the components of the system up to temperature. A first seal 218a is disposed at the joint between the outer walls 214a, 214b of the treatment chambers and the air supply plenum 208 and extends around the entire length of the joint. A second seal 218b is disposed at the joint between the outer walls 214a, 214b of the treatment chambers and the air return plenum 210 and extends around the entire length of the joint.

A first resistive element 224a is secured within the treatment unit 202 between the air supply plenum 208 and the three treatment chambers 206a, 206b, 206c so that it intersects a path from the interior of the air supply plenum 208 to the interior of the treatment chambers. The resistive element 224a comprises a porous but resistive barrier layer 226a, such as a fabric layer, and a sealable vent 228a. The resistive barrier layer 226a is secured across the area enclosed by the top of the walls 212 of the air supply plenum 208 and the vent 228a is secured across the area enclosed by the bottom of the outer walls 214a, 214b of the treatment unit 202. A second resistive element 224b is secured within the treatment unit 202 between the three treatment chambers 206a, 206b, 206c and the air return plenum 210 and so that it intersects a path from the interior of the treatment chambers to the interior of the air return plenum 210. The resistive element 224b comprises a porous but resistive barrier layer 226b, such as a fabric layer, and a sealable vent 228b. The resistive barrier layer 226b is secured across the area enclosed by the top of the outer walls 214a, 214b of the treatment unit 202 and the vent 228a is secured across the area enclosed by the bottom of the wall 216 of the air return plenum 210. The resistive barrier layers 226a, 226b comprise filter material for removing pathogens from air passing through the layers. The vents 228a, -14 - 228b each comprise three sections corresponding to the three treatment chambers 206a, 206b, 206c, positioned so that each section of the first vent 228a is aligned with the entrance to one of the treatment chambers, and each section of the second vent 228b is aligned with the exit from one of the treatment chambers. The sections of the vents 228a, 228b can be individually opened and sealed so that the entrance and exit of a particular treatment chamber may be selectively opened and sealed by a user.

The interior of the treatment chambers 206a, 206b, 206c accommodate potentially infected personal protective equipment 132, for example masks, can be loaded onto supports within the chambers for disinfection. At least one sensor is situated within each of the treatment chambers 206a, 206b, 206c. In this example, temperature sensors 234a, 234b, 234c are mounted within the treatment chambers 206a, 206b, 206c -one sensor for each chamber. The temperature sensors 234a, 234b, 234c measure the temperature of the air within the treatment chambers 206a, 206b, 206c, in which case it is either assumed that the equipment 132 is at the same temperature as the air or a calibration is used to convert the measured air temperature to a temperature for the equipment 132. Alternatively, the sensors are arranged to contact the equipment 132 within the chambers so as to directly measure the temperature of the equipment. The treatment unit 202 comprises means (not shown) for individually accessing the interior of each of the treatment chambers. For example each treatment chamber may comprise a side hatch arranged to open perpendicular to the direction of air flow through the chamber. Alternatively each of the treatment chambers may be formed as a drawer slidable on runners mounted on the walls of the treatment chamber. In any case, the treatment unit 202 comprises an interlock (not shown) for sealing the means for accessing the interior of the treatment chambers.

The treatment unit 202 is connected to the circulation module 104 by an air return duct 136 and an air supply duct 138, each of which is rigid in this example. The air return duct 136 and air supply duct 138 are received through openings in the wall 216 of the air return plenum 210, the wall 212 of the air supply plenum 208, and the housing 144 of the circulation module 104. The housing 144 of the circulation module 104 encloses an air circulation volume 150 which accommodates a fan 152 and a heating element 154. The circulation module 104 also comprises a control unit 256. The control unit 256 includes user input interface 258 for receiving user input to control the operation of the disinfection system 200, a timer 260, and multiple displays 262a, 262b. 262c each corresponding to one of the three treatment chambers and capable of displaying information to the user about the operation of that treatment chamber within the system 200, such as the temperature in each chamber as measured by its respect sensor 234a, 234b, 234c or the time remaining on the timer 260.

-15 -The fan 152 provides means for circulating air around the disinfection system 200 as shown by the arrows in Figure 2. The fan 152 drives air across the heating element 154 which heats the air before it is circulated throughout the system 200. The air supply duct 138 provides a channel through which air is supplied from the circulation unit to the treatment unit 202. The heated air supplied through the air supply duct 138 is prevented from immediately passing into the treatment chambers 206a, 206b, 206c by the porous but resistive barrier layer 226a of the first resistive element 224a. The air supply plenum 208 spanning the three treatment chambers thus acts to collect the heated air arriving through the air supply duct 138 before the air passes through the resistive element 224a into the treatment chambers. As described above this ensures that the air emerging from the air supply plenum 208 into each of the treatment chambers is at an approximately uniform temperature and flows into each of the treatment chambers at an approximately constant rate across the area of the resistive element 224a. The resistive barrier layer 224a filters the heated air as it passes through the first resistive element 124a to remove some pathogens from the air. Where it is desired for heated air to pass into one of the treatment chambers (because the chamber contains personal protective equipment to be disinfected), the sections of the vents 228a, 228b corresponding to that treatment chamber can be opened to allow air to pass from the air supply plenum 208 through that treatment chamber and into the air return plenum 210. Where it is desired for heated air not to pass into one of the treatment chambers (for example because the chamber is empty, and so there is no need to heat it), the sections of the vents 228a, 228b corresponding to that treatment chamber can be closed to prevent air from pass into that treatment chamber from the air supply plenum 208; the sections of the vents corresponding to the other treatment chambers remain open.

The first resistive element 224a is configured to provide an air resistance much greater than any air resistance resulting from personal protective equipment within the treatment chambers. This means that the presence or absence of equipment within a treatment chambers does not significantly affect the total air resistance along a flow path from the air supply plenum 208 to the air return plenum 210 through any one treatment chamber as compared to any other treatment chamber. Therefore, the presence or absence of equipment within a particular treatment chamber does not significantly affect the air flow rate through that treatment chamber as compared to the air flow rate through other treatment chambers. Without the air resistance provided by the first resistive element 224a, the heated air in the system 200 of Figure 2 might tend to flow more readily through the second treatment chamber 206b (relative to the first or third treatment chambers 206a, 206c because they contain less or no equipment) resulting in uneven heating of the treatment chambers. This problem is ameliorated by introducing the resistive element 224a which -16 -dominates the net air resistance through each chamber making it more or less equally easy (or difficult) for air to flow through any of the three treatment chambers regardless of the presence of equipment within the chamber. This means that the air will flow more or less equally through each of the three chambers in use, thus resulting in the equipment within the three chambers being treated in parallel.

The porous but air resistant barrier layer 226b of the second resistive element 224b prevents air flowing through the treatment chambers 206a, 206b, 206c from immediately passing into the air return plenum 210. Without the second resistive element 224b, the heated air within the treatment chamber would tend to be quickly extracted from the treatment chamber along a path of least air resistance through the chamber. Thus, in the first chamber 206a, which contains one piece of equipment 132 positioned at one side in the chamber, the heated air would tend to flow through the chamber on the opposite side of the chamber as this flow path would encounter less air resistance, resulting in the equipment being poorly and unevenly heated (particular on its side closest to the side of the chamber). With the second resistive element 224b, the heated air is prevented from immediately flowing through and out of the treatment chamber and so will tend to circulate within the treatment chamber before passing through to the air return plenum 210, resulting in more effective and even heating of the equipment 132. The second resistive barrier layer 226b also filters the heated air as it passes through the second resistive element 224b to remove some pathogens from the air.

Therefore, while the first resistive element makes for more uniform air flow and heating between treatment chambers, the second resistive element makes for more uniform air flow and heating within treatment chambers.

The air that passes from the treatment chambers 206a, 206b, 206c to the air return plenum 210 is extracted through the air return duct 136 under the action of the fan 152. The air returns to the circulation module 104 where the fan 152 drives the air through the air circulation volume 150 towards the heating element 154 and on to circulate the air again through the disinfection system 200. The disinfection system 200 is a closed system for recirculating a flow of hot air over the equipment being disinfected. This prevents contamination and heating of the surrounding room, and also provides for a more stable air temperature within the system 200 while also reducing the power requirements for the circulation module 104.

As described above, the air resistance provided by the first and second resistive elements is larger than the air resistance generated by the presence of a mask (or other items) within one of the treatment chambers so as to promote more uniform air flow between the parallel treatment chambers. In more detail, if the variation in the air flow rate between an empty -17 -chamber and a full chamber is to be no more than 25%, then the air resistance provided by the resistive elements in the system must be at least 3 times more than the air resistance generated by the item in the chamber. A mask in a closed treatment chamber, where the mask significantly obstructs the flow through the chamber, generates an aerodynamic pressure drop of approximately 2 Pa (depending on the extent to which the mask occupies the area of the chamber). Therefore, the resistive elements should provide air resistance to generate an aerodynamic pressure drop of at least approximately 6 Pa. Therefore, in this case, the total aerodynamic pressure drop along an air flow path through an empty chamber would be approximate 6 Pa (generated by the resistive elements) and along an air flow path through a full treatment chamber would be 8 Pa (2 Pa generated by the masks, and 6 generated by the resistive elements). Thus, the air resistance through the empty chamber is 25% lower, limiting the resulting air flow rate variation to approximately 25% higher than the filled chamber. This flow resistance can be generate by both the first or second resistive elements (i.e. resistance to air flowing into the treatment chambers, or resistance to air flowing out of the treatment chambers) as in either case the resistance relates to the air flow along a path a particular chamber.

The resistive elements may comprises an array of nozzles of suitable diameter and length, a perforated plate, or a conventional filter element such as a high-efficiency particulate air (HEPA) type pleated filter. The dimensions of the nozzles or perforations are designed using standard formulae, and filters likewise can be adapted to provide the target resistance value as described above. A nozzle array or perforated-plate is advantageous as it will not be blocked by the accumulation of dust over time. A filter is advantageous because it can clean the air during circulation while also providing the requisite air resistance -in particular a HEPA standard clean air supply prevents the passage of bacterial or viral particles.

In use, a user accesses the interior of at least one of the treatment chambers 206a, 206b, 206c as described above to place potentially infected items, in particular personal protective equipment 132 such as masks, onto support provided within the treatment chambers. The equipment 132 may be secured to prevent it from being dislodged by the air flow during disinfection treatment. In this example, the treatment chambers are not accessed via a hinged air return plenum as in Figure 1 as to do so would result in all three treatment chambers 206a, 206b, 206c being unsealed simultaneously. Instead, in this example each of the treatment chambers 206a, 206b, 206c is individually accessible, for example via a side hatch in each chamber. Once the user has placed equipment 132 within a particular treatment chamber, the user then seals that chamber. The user interacts with the control unit 256 to initiate a disinfection cycle. The user input interface 258 includes a power control to enable a user to power up the circulation module 104, a control to enable a user to select -18 -the treatment chamber in which they have deposited their equipment, as well as controls for selecting the temperature to which the user wishes to heat the equipment 132 (which may depend on the level of disinfection the user wishes to achieve, or the equipment placed within the treatment chamber). The user then selects on the timer 260 the desired length of the cycle (which again may depend on the desired disinfection and the equipment). The user input interface 258 may include a number of pre-set disinfection cycles stored in a memory of the control unit, each cycle operating at a particular temperature for a particular length of time that is suited to a certain type of equipment or a certain pathogen. The displays 262a, 262b, 262c convey information to the user about each of the three treatment chambers 206a, 206b, 206c respectively. For example the real-time temperature inside each of the treatment chambers as measured by the sensors 234a, 234b, 234c and the length of time remaining on the treatment cycle.

This configuration conveniently enables the treatment chambers to be utilised independently by different users. For example, a first user may load one face mask into the first treatment chamber 206a (as shown in Figure 2) and then interact with the control unit to begin a 30 minute treatment cycle. At a later time a second user may load two face marks into the third treatment chamber 206c (as shown in Figure 2). As the third chamber can be accessed independently of the first chamber, the first user's disinfection cycle need not be disrupted by the second user loading that chamber. The second user may wish to close the sections of the vents 228a, 228b corresponding to the third treatment chamber while loading that chamber to prevent heated air passing into the chamber during loading. The conditions within the first and third chambers are measured by independent sensors 234a, 234c and thus the two users can independently monitor the progress of the disinfection cycle in each chamber via the respective displays 262a, 262c and remove their equipment once each user's cycle is complete. The second treatment chamber 206b in this example is empty, therefore the sections of the vents 228a, 228b corresponding to the second treatment chamber 206b may be closed to prevent this chamber being heated unnecessarily and thus to reduce energy consumption. The control unit 256 may control the operation of the vents 228a, 228b so as to open only the sections of the vents corresponding to treatment chambers that are in use, according to the user input at the user input interface 258. As each treatment chamber within the treatment unit 202 can be used independently, each chamber may be assigned to a particular user so that that chamber is always used by the same person. This is useful for preventing cross contamination from infected equipment to clean equipment and between people.

During the treatment cycle, the fan 152 circulates air from the circulation module 104 into the treatment unit 202 via the air supply duct 138. The heated air is collected in the air supply -19 -plenum 108 before passing through the first porous resistive element 224a into the treatment chambers 206a, 206b, 206c. Heat is transferred from the air to the potentially infected equipment 132 thereby to heat the equipment. The air then flows from the three treatment chambers across the second porous resistive element 224b and into the air return plenum 210 from which the air is extracted through the air return duct 136 under the action of the fan 152. The air is then recirculated as described. Once the cycle is complete, the user accesses the interior of the relevant treatment chamber to remove the disinfected equipment 132. If further capacity for disinfecting equipment is required, a larger disinfection system can be constructed by adding further treatment modules to the three modules already combined in this example.

Figure 3 is a block diagram showing the operation of the disinfection system of Figures 1 and 2. The system comprises a circulation module 104 connected to a treatment module 102, or a group of treatment modules interconnected as a treatment unit 202. The treatment module or unit 102, 202 comprises at least one sensor 134, 234 to measure conditions within a treatment chamber, and an interlock 122 for sealing a means for accessing the chamber. The circulation module 104 comprises a fan 152 for driving a circulation of air within the system as shown by the arrows, a heating element 154 for heating the air circulated by the fan 152, and a control unit 156, 256 for controlling the operation of the fan 152 and heating element 154. The heating element 154 and the fan 152 are off-the-shelf components, preferably repurposed from a household hairdryer, fan oven, or other commodity hardware. The control unit 156, 256 comprises at least one processing unit 302 (such as a microprocessor, microcontroller or Central Processing Unit or an ASIC). The processing unit 302 is configured to receive readings from the one or more sensors 134, 234, for example a measure of the temperature in the treatment chamber. The processing unit is also configured to receive input from the user input interface 158, 258, for example to receive a temperature setting input by a user, and input from the timer 160, 260, for example the time remaining on the timer. The display 162, 262 is configured to receive input from the timer 160,260 and user input interface 158, 258 so as to display information input from the timer and information input by a user. The processing unit 302 is configured to control the timer 160, 260 at least to stop and start the timer depending on whether certain disinfection conditions are present within the treatment chamber (as measured by the sensors 134, 234). The processing unit 302 is configured to output data to a heating element control interface 304 and a fan control interface 306 which convert that data from the processing unit 302 to control signals to operate the heating element 154 and fan 152 respectively. The processing unit 302 is also configured to control the interlock 122 sealing the treatment chamber of the treatment module or unit 102, 202 to lock the chamber while treatment is in progress and -20 -unlock it when the treatment is complete. The treatment module or unit 102, 202 is passive in that it requires no power supply. The circulation module 104 may be powered from a mains outlet. Alternatively, the circulation module 104 may be powered from an in-car power supply such as an automobile auxiliary power outlet (an in-car cigarette lighter socket) for improved portability. Features of the system which minimise power consumption (recirculation of air, insulated walls, low thermal mass components, and air-tight seals) mean that the power supplied by an automobile auxiliary power outlet is sufficient to power the circulation module. In addition, the system may be battery powered to enable increased portability and convenience.

When a user has deposited items to be disinfected within a treatment chamber of the treatment module or unit 102, 202 the user interacts with the user input interface 158, 258 to select a temperature at which the items are to be treated, for example 70°C. The user input interface 158, 258 controls the display 162, 262 so that this user selected temperature is displayed to the user. The user then selects on the timer 160, 260 the time for which the items must be kept at or above the user selected temperature in order for the disinfection cycle to be complete, for example 30 minutes. The timer 160, 260 controls the display 162, 262 so that this user selected time is displayed to the user. The processing unit 302 then receives a reading from the sensors 134, 234 as to the current temperature in the treatment chamber. If the temperature in the chamber is below the user selected temperature, the processing unit 302 turns on the heating element 154 via the heating element control interface 304 and turns on the fan 152 via the fan control interface 306, so that the fan and heating element together cause heated air to be circulated into the treatment chamber. Once the processing unit 302 determines that the temperature within the chamber has reached the user selected temperature (as measured by the sensors 134, 234) the processing unit 302 controls the timer 160, 260 to begin counting down the user selected time. It is important that the timer does not begin counting down until the temperature within the chamber has reached the desired level, as the temperature is critical for disinfecting the items. The processing unit reduces the power of the heating element 154 and fan 152 to as to maintain a steady temperature within the chamber at the user selected temperature. In the event that the temperature within the treatment chamber drops below the user selected temperature, the processing unit 302 pauses the timer. This ensures that the item spends the entire length of the user selected time at or above the critical temperature selected by the user. This is particularly useful where power supply is intermittent, and where it is important to verify that the items have been exposed to a certain temperature for a minimum length of time. Once the timer has finished, the items in the treatment chamber will have been exposed to the user selected temperature for the user selected time (either in a single -21 -period or multiple interrupted periods) meaning that the treatment cycle is complete. The processing unit 302 controls the interlock 122 so as to release the chamber so that the user may access the disinfected items. The processing unit 302 does not unlock the chamber until the treatment cycle is complete so that the chamber cannot be unsealed by a user during operation.

Figures 4a and 4b are perspective views, and Figure 4c is a plan view, of a base module 400 of a second embodiment of the disinfection system. The base module 400 comprises a container 402 having outer walls on which a removable lid 404 is seated to provide an airtight seal of the container 402. The base module 400 comprises a control panel 406 for receiving user input to control the conditions within the container in use. The control panel 406 has a timer 408, a temperature control 410, and a power switch 412. The interior of the container 402 is divided into a base module treatment chamber 414 and a base module air circulation chamber 416 by a base module partition 418. The base module partition 418 contains vents 420 providing a channel for air flow across the partition 418. Other than the vents 420, the base module partition 418 prevents any air flow between the base module treatment chamber 414 and the base module air circulation chamber 416. The base module partition 418 has an opening through which a fan heater 422 is received, so that an air inlet of the fan heater 422 is positioned in the base module air circulation chamber 416 and an air outlet of the fan heater 422 is positioned in the base module treatment chamber 414. While the lid 404 is shown in Figures 4a and 4b as extending across the entire base module 400, the base module 400 may instead be provided with a removable cover across the treatment chamber 414, to allow user access to the treatment chamber 414, and a permanent cover across the air circulation chamber 416 so seal the air circulation chamber 416. This reduces opportunities for heated air might escape from within the system so as to improve efficiency.

Items to be disinfected, such as personal protective equipment 132, are placed by a user into the base module treatment chamber 414. The container 402 is sealed by replacing the lid 404. The user interacts with the control panel 406 to power on the base module, using the power switch 412, to set a temperature for a disinfection cycle using the temperature control 410 and to set a length of time for the disinfection cycle using the timer 408. The system controls the fan heater 422 so as to intake air from the base module air circulation chamber 416, heat that air and output the heated air into the base module treatment chamber 414. Heat is transferred from the heated air to the equipment 132 thereby to heat the equipment to disinfect the equipment. As heated air is driven into the base module treatment chamber 414 by the fan heater 422, air from within the base module treatment chamber 414 is driven out through the vents 420 and into the base module air circulation chamber 416. This air is then heated and recirculated around the system by the fan heater -22 - 422 as shown by the arrows in Figure 4c. Once the system has heated the equipment 132 within the treatment chamber to the target temperature set by the user (as measured by a sensor within the chamber), the system starts the timer 408 and maintains the equipment at the target temperature for the duration of the timer as described with reference to Figure 3.

The base module 400 is suitable for disinfecting a number of small items, such as the four face masks shown in Figures 4b and 4c, or a smaller number of larger items, for example a visor. The base module 400 of this second embodiment provides the treatment module and air circulation module as a single integrated unit so that the base module 400 can be operated as a stand-alone device. The base module 400 is compact so as to be conveniently portable and to have lower power requirements, making it suitable for personal use such as by community health workers.

Figure 5 is a perspective view of the second embodiment of the disinfection system showing the base module 400 and an extension module 500. The airtight lid of the base module shown in Figure 4 has been replaced with a porous lid 502 having an array of perforations 503a, 503b which provide passages through which air can flow between the interior of the base module 400 and the interior of the extension module 500. The extension module comprises a flexible casing 504 which is supported by a collapsible and erectable spiral frame 506. The extension module 500 is secured at its base to the base module 400 via fixings (not shown) at the base of the casing 504 and the frame 506 and on the top of the perforated lid 502. The base module 400 and extension module 500 together form an airtight closed system. The extension module 500 comprises an extension module partition 508 which substantially divides the extension module into an extension module treatment space 510 on one side of the partition 508 and an extension module air return space 512 on the other side of the partition 508. The extension module partition 508 is aligned in the same plane as the base module partition 418, and when the extension module 500 is attached to the base module the vents 420 in the base module partition are closed so that air cannot flow from the base module treatment chamber 414 into the base module air circulation chamber 416 other than by circulating first around the extension module 500. The attachment of the extension module 500 to the base module 400 may automatically cause the vents 420 to close. This divides the perforations in the lid 502 into a first set of perforations 503a on one side, which provide an air flow passage from the base module treatment chamber 414 into the extension module treatment space 510, and a second set of perforations 503b on the other side, which provide an air flow passage from the extension module air return space 512 into the base module circulation chamber 416. The extension module treatment space 510 accommodates a support 514 to retain equipment within the extension module treatment space 510 for disinfection treatment. In this example the -23 -support 514 is an upright rack. The extension module 500 comprises a hatch 516 in its top side through which a user can access the extension module treatment space 510 to load and unload equipment to or from the support 514. Alternatively or additionally, a side hatch is provided in the casing 504. The base module 400 comprises a control panel 406 as before.

The extension module 500 provides a means for a user to scale the system to increase the capacity for disinfecting equipment, rather than relying on the capacity of the base module treatment chamber 414 alone. The flexible casing 504 of the extension module 500 enables a user to vary the volume of the extension module according to the required capacity. For example, the extension module in Figure 5 is shown accommodating 11 face masks, however if the extension module was only required to accommodate 5 masks, the spiral frame 506 could be collapsed somewhat to reduce the internal volume of the extension module 500 to just what is required to accommodate the 5 masks. If more than 11 face masks were being disinfected, the spiral frame 506 could be erected further to expand the space within the extension module 500 to accommodate more masks. The flexible casing 504 is configured to expand and contract accordingly. The size of the support 514 too can extend or contract to suit the space available within the extension module 500, for example the rack may be telescopic, or rows of the rack may be added or removed. This enables a user to vary the volume of the extension module to reduce the power requirements for the system by minimising the volume that must be heated to just that necessary to accommodate the equipment being disinfected. In addition, when the system is not in use the extension module 500 can be entirely collapsed for stowage for increased portability and convenience. The flexible casing 504 can be removed from the base module 400 or collapsed to expose the support 514 for ease of loading items onto the support 514. When the items have been loaded onto the support 514, the casing 504 is re-attached to the base module 400, or re-erected around the support 514 to enclose the support 514 within the volume of the extension module 500. The components of the system are made from or comprise heat insulating materials (such as polystyrene foam) with a low thermal mass (or heat capacity) so as to prevent heat from within the system being transferred outside the system and to minimise the heat energy required to bring the components of the system up to temperature. Alternatively, the extension module casing 504 may be double walled, with a layer of static air between the walls, to insulate the extension module 500. VVhile the casing 504 is described as flexible and collapsible, the extension module 500 could instead be provided with a rigid exterior.

Figure 6 is cross-sectional view of the second embodiment of the disinfection system.

Figure 6 shows the operation of the system during a disinfection cycle. A user accesses the -24 -extension module treatment space 510 via the hatch 516 to load items to be disinfected onto the support 514. The user then closes the hatch 516 to seal the interior of the extension module 500. The user interacts with the control panel 406 as described above to begin a treatment cycle for a particular time and temperature. The fan heater 422 then extracts air from the base module air circulation chamber 416, and heats the air as it forces the air into the base module treatment chamber 414. The base module treatment chamber 414 may also contain items to be disinfected, or, as in the example shown in Figure 6, the base mode treatment chamber may be empty. The heated air is prevented from flowing directly from the base module treatment chamber 414 into the base module air circulation chamber 416 by the base module partition 418 which is not porous because the vents 420 in the partition are closed while the extension module 500 is secured to the base module 400. The air therefore flows through the perforations 503a of the lid 502 and into the extension module treatment space 510. The perforations act to disperse the air flowing into the extension module to provide more even heating within the extension module. The base module treatment chamber acts as an air supply plenum for the air supplied into the extension module treatment space 510, providing the same function as the air supply plenum of the first embodiment. The heated air flows up through the extension module treatment space 510, between one side of the extension module partition 508 and the extension module casing 504. Heat transfers from the heated air to the items on the support 514 thereby to heat the items and disinfect the items. The air then flows over the top of the extension module partition 508 and down through the extension mode air return space 512, between the other side of the extension module partition 508 and the extension module casing 504. The air then passes through the perforations 503b in the lid 502 and into the base module air circulation chamber 416, from which the air is again extracted, heated and circulated around the system as described. The treatment cycle continues until the equipment has been maintained at the user defined target temperature for the user defined time period. Once the treatment cycle ends, the hatch 516 may be unlocked to enable a user to access the extension module treatment space 510 to remove the items that have been disinfected.

As described above, the extension module partition 508 is aligned in the same plane as the base module partition 418, so that the system defines a one-way flow path for air as shown by the arrows in Figure 6. Air flows from the base module air circulation chamber 416, to the base module treatment chamber 414, to the extension module treatment space 510, to the extension module air return space 512, and back into the base module air circulation chamber 416. The items in the extension module treatment space 510 are shown in this example to be stacked one on top of the other. However, the items may alternatively be -25 -held in a different configuration, such as in a spiral stack, to promote even air flow over each of the items being disinfected and effective heat transfer from the heated air to the items.

Figures 7a to 7d are perspective views of the second embodiment of the disinfection system in use. Figure 7a shows a user accessing the extension module 500 via the hatch 516 to load personal protective equipment 132 to be disinfected onto the support located within the extension module treatment space. Afterwards, the user closes the hatch 516 to seal the interior of the extension module 500. Figure 7b shows the user interacting with the control panel 406 as described above to begin a treatment cycle. The control panel 406 comprises a timer for a user to set a length of time for the disinfection cycle, a temperature control for a user to set a temperature for the disinfection cycle, and a power switch for the user to power-on the base module 400. The fan and heater within the base module heats air and circulates the heated air around the system to disinfect the equipment 132 as described with reference to Figures 5 and 6. The fan and heater are controlled to achieve the desired temperature conditions within the system for the desired period of time as described below.

Once the treatment cycle is complete, the user unseals the hatch 516 to access the interior of the extension module 500 to remove the equipment 132 that has been disinfected as shown in Figure 7c. When the system is not in use, the extension module 500 is collapsed for storage, by collapsing the frame of the extension module as shown in Figure 7d.

The operation of the second embodiment of the disinfection system is analogous to the operation of the first embodiment as described with reference to Figure 3. The base module treatment chamber 414 and the extension module treatment space 510 each comprise at least one sensor (not shown) to measure conditions within the base module treatment chamber 414 and the extension module treatment space 510. The fan heater 422 drives a circulation of heated air within the system as shown by the arrows in Figure 6. The control panel 406 comprises a control unit for controlling the operation of the fan heater 422. The fan heater 422 is preferably an off-the-shelf component, preferably repurposed from a household hairdryer, fan oven, or other commodity hardware. The control unit receives readings from the one or more sensors in the base module treatment chamber 414 and the extension module treatment space 510, for example a temperature measure. The control unit is also configured to receive the user input at the control panel 406, for example a temperature setting input by a user at the temperature control and a time setting input by a user at the timer. The control unit is configured to control the timer, at least to stop and start the timer depending on whether certain disinfection conditions are present within the base module treatment chamber 414 and the extension module treatment space 510 (as measured by the sensors).

-26 -When a user has deposited items to be disinfected within the base module treatment chamber 414 and/or the extension module treatment space 510, the user interacts with the control panel 406 to select a temperature at which the items are to be treated. In this example the user selects 70°C. The user then selects, using the timer, the time for which the items must be kept at or above 70°C in order for the disinfection cycle to be complete. In this example the user selects 30 minutes. The control unit then receives a reading from the sensors as to the current temperature in the base module treatment chamber 414 and the extension module treatment space 510. If the temperatures are below 70°C, the processing unit 302 turns on the fan heater 422 to cause heated air to be circulated into the base module treatment chamber 414 and the extension module treatment space 510 as described. The base module treatment chamber 414 and the extension module treatment space 510 are heated until they reach the target temperature of 70°C as measured by the sensors. Once the control unit determines, via the sensor readings, that the temperature within the chamber has reached 70°C, the control unit controls the timer to begin counting down the 30 minutes. It is important that the timer does not begin counting down until the temperature within the chamber has reached the desired level, as it may be critical for the temperature of the items being disinfected to be at or above the target temperature to disinfect the items. The control unit reduces the power of the fan heater 422 to as to maintain a steady temperature of 70°C within the base module treatment chamber 414 and the extension module treatment space 510. In the event that the temperature within the treatment chamber drops below 70°C, the control unit pauses the timer. This ensures that the item spends 30 minutes at or above the critical temperature selected by the user. This is particularly useful where power supply is intermittent, and where it is important to verify that the items have been exposed to a certain temperature for a minimum length of time. The control unit will ramp up power to the fan heater 422 to increase the temperature in the base module treatment chamber 414 and the extension module treatment space 510 back up to the target temperature of 70°C and once the temperature is achieved the timer countdown continues. Once the timer has finished, the items in the treatment chamber will have been exposed to 70°C heat for 30 minutes (either in a single period or multiple interrupted periods) meaning that the treatment cycle is complete. The control unit powers down the fan heater 422 and the user opens the hatch 516 to retrieve the disinfected items.

The base module 400 may be powered from a mains outlet. Alternatively, the base module 400 may be powered from a connection to an in-car power supply such as an automobile auxiliary power outlet for improved portability. Features of the system which minimise power consumption (recirculation of air, airtight seals around the system, variable volume extension module) mean that the power supplied by an automobile auxiliary power outlet is sufficient to -27 -power the base module 400. In addition, the system may be battery powered to enable increased portability and convenience.

The second embodiment is described above with the extension module partition 508 dividing the extension module 500 into two segments along a vertical axis. However, the extension module may instead be formed as an inner casing and a concentric outer casing with a gap between the inner and outer casing. In this case, the space within the inner casing is a central treatment space and the gap between the inner and outer concentric casings is the air return space. The treatment space contains the items being disinfected, and heated air from the base module flows up through the central treatment space. When the air reaches the top of the extension module, the air is directed radially outwards and down through the gap between the inner and outer concentric casings and into the base module. In this case, the fan heater and base module partition are configured to create a central base module treatment chamber and a surrounding base module air circulation chamber to correspond to the features of extension module. This configuration is optimised for collapsing the extension module because of the radial symmetry of the extension module.

Figure 8 is a perspective view of a third embodiment of the disinfection system. The system 800 comprises a walled container 802 and a lid 804. The lid 804 is attached to the container 804 via a hinged connection 805 between the lid and one of the walls of the container. The lid 804 is arranged to seal the interior of the container 802, for example by an interlock which latches the lid 804 to a wall of the container, so that the lid cannot be opened in use while a disinfection cycle is in progress. The interior of the container 802 is divided by a partition wall 806 into an air supply channel 808, a treatment space 810, and an air return channel 812. The partition wall 806 has two limbs, a first limb 806a which is not porous, and a second limb 806b which is porous due to a series of apertures 814 in the second limb 806b which provide passages for air to pass through. The second limb 806b of the partition wall extends to contact the wall of the container 802 so that the only passage for air to flow from the air supply channel 808 into the treatment space 810 is through the apertures 814. The apertures 814 in the second limb 806b of the partition wall act to more evenly diffuse and distribute air flowing from the air supply channel 808 into the treatment space 810 so that items within the treatment space 810 are more evenly heated by the air. The partition wall 806 runs parallel to the walls of the container 802 so that the air supply channel 808 and air return channel 812 are bounded on one side by the partition wall 806 and on the other side by the walls of the container 802. When the lid 804 seals the container 802, the lid forms an airtight contact with the top of walls of the container and the top of the partition wall 806 thereby to enclose the air supply channel 808 and air supply channel 812.

-28 -The treatment space 810 accommodates supports 816 for retaining personal protective equipment within the treatment space 810. The first limb 806a of the partition wall does not extend to contact the walls of the container 802, leaving a gap through which air from the treatment space 810 can pass into the air return channel 812. The air return channel 812 is partitioned from the air supply channel 808 by a block 818. The block 818 has an opening through which a a fan heater 820 is mounted. The fan heater 820 utilises elements from commodity hardware, such as the fan and heating element commonly found in a household hair dryer. The opening is airtight when the fan heater 820 is mounted. The fan heater 820 contains a fan and heating element to provide means for heating and driving air from the air return channel 812 into the air supply channel 808 so as to circulate air around the system 800. The system 800 further comprises a control panel 822, which has a timer 824 for receiving a user input of a length of time for a disinfection cycle, a temperature control 826 for receiving user input of a temperature for the disinfection cycle, and a temperature sensor 828 which protrudes through the wall of the container 802 and into the treatment space 810 to measure the temperature within the treatment space. The temperature sensor measures the temperature of the air within the treatment space 810 in which case it is either assumed that the equipment items within the chamber are at the same temperature as the air or a calibration is used to convert the measured air temperature to a temperature for the items. Alternatively, the sensor is arranged to contact an item within the chamber so as to directly measure the temperature of the item. The control panel 822 also comprises a built-in control unit configured to control the operation of the fan heater 820 based on readings of the sensor 828. A power cable 830 connects the system to a power source 800, such as to an automobile auxiliary power outlet or a mains power supply, to power the control panel 822 and the fan heater 820. The system 800 is a closed and compact system in that it is sealed to the outside, and the volume of air which must be heated and recirculates within and around the system 800 is minimised. This reduces the power consumption of the system 800 allowing the system to be powered by a wider range of power supplies to increase convenience and portability. The walls of the container walls 802, the partition 806, the supports 816, the block 818 and other components of the system 800 are made from or comprise heat insulating materials (such as polystyrene foam) with a low thermal mass (or heat capacity) so as to prevent heat from within the system being transferred outside the system and to minimise the heat energy required to bring the components of the system up to temperature.

In use, a user opens the lid 804 of the container 802 to load potentially infected items such as personal protective equipment onto the supports 816 within the treatment space 810.

The lid 804 is then closed to seal the interior of the container 802, and the lid 804 is secured -29 -to the walls of the container, for example by an interlock (not shown) so that the lid cannot be opened accidentally during a treatment cycle. The user interacts with the control panel 822 to select a temperature at which the items are to be treated. In this example the user selects 70°C. The user then selects, using the timer 824, the time for which the items must be kept at or above 70°C in order for the disinfection cycle to be complete. In this example the user selects 30 minutes. The control unit of the control panel 822 then receives a reading from the sensors as to the current temperature in the treatment space 810. If the temperature inside the treatment space 810 is below 70°C, the control unit turns on the fan heater 820 to cause heated air to be circulated through the system 800. The one-way circulation path of air through the system 800 is shown by the arrows in Figure 8. The air is heated by the fan heater 820 and driven along the air supply channel 808, through the apertures 814 of the second limb 806b of the partition wall 806 and into the treatment space 810. Each of the apertures 814 is small enough to allow only a small portion of the total air flow to pass through it. Therefore, while some air will pass through the first aperture encountered along the air supply channel 808, most air will be forced to flow onwards to other apertures to pass through the partition wall. The acts to distribute the air flowing across the partition wall more evenly thereby to provide more even heating throughout the treatment space 810. The treatment space 810 is heated by the air flowing into the space until the items loaded onto the supports 816 reach the target temperature of 70°C as measured by the sensors 822. Once the control unit determines, via the sensor readings, that the temperature of the items in the treatment space 810 has reached 70°C, the control unit activates the timer to begin counting down the 30 minutes. The control unit at this point also reduces the power of the fan heater 820 to a level that maintains a steady temperature of 70°C within the treatment space 810, by introducing the same amount of heat energy into the treatment space 810 as is lost from the treatment space 810. In the event that the temperature within the treatment chamber drops below 70°C, the control unit pauses the timer. This ensures that the item within the treatment space 810 spends 30 minutes at or above the critical temperature selected by the user. If the temperature of the items as measured by the sensor 828 drops below the target temperature, the control unit will ramp up power to the fan heater 820 to increase the temperature in treatment space 810 back up to the target temperature of 70°C. Once the target temperature is achieved again, the timer countdown continues. The air flows out of the treatment space 810 through the gap between the first limb 806a of the partition wall 806 and the wall of the container 802 and into the air return channel 812. The air is then extracted from the air return channel 812 through an inlet of the fan heater 820, and is heated and expelled from an outlet of the fan heater 820 into the air supply channel 808 to repeat the circulation as described. Once the timer has finished, the items in the treatment chamber will have been exposed to 70°C heat -30 -for 30 minutes (either in a single period or multiple interrupted periods) meaning that the treatment cycle is complete. The control unit powers off the fan heater 820 and the lid 804 is unlocked so as to allow the user to retrieve the disinfected items.

Figure 9 is a perspective view of a fourth embodiment of the disinfection system. The disinfection system 900 comprises a treatment capsule 902 and a circulation unit 904 having a rigid tube casing 905 that contains means for heating and circulating air around the system 900 such as a fan heater. The treatment capsule 902 has a housing 906 having a top hatch 907 by which user can access the interior of the treatment capsule 902 to load potentially infected items such as masks 908 for disinfecting. The housing 906 may be rigid or alternatively the housing 906 may be flexible (similar to the flexible casing 504 described with reference to Figure 5) so as to enable it to expand to provide a variable treatment volume and to collapse for convenient storage. The treatment capsule 902 has at its base a perforated dome 910 for inlet of heated air from the circulation unit 904 into the treatment capsule 902. The treatment capsule 902 has a duct 912 for outlet of air from the treatment capsule 902 into the circulation unit 904. A control panel 912, having a power switch, a timer, a temperature control, and a digital display is located on the exterior of the tube casing 905 of the circulation unit 904. In use, the circulation unit 904 heats and circulates air through the perforations in the dome 910 and into the treatment capsule 902. The perforations in the dome 910 disperse the air to flowing into the treatment capsule 902 in an analogous way to the apertures 814 of the third embodiment as described with reference to Figure 8. The dispersed air makes for more uniform and effective heating of the masks 908 within the treatment capsule. Heat from the air is transferred to the masks 908 within the capsule 902 to heat the masks and disinfect the masks. Once the air has flowed over the masks 908 the air flows out of the treatment capsule through the outlet duct 912 and back into the circulation unit 904 for heating and recirculation around the system 900. The treatment capsule 902 contains a temperature sensor for measuring the temperature of the masks 908 to verify that the masks are heated to the desired temperature. The fan and heater in the circulation unit 904 are controlled on the basis of the sensor readings to maintain the target temperature for the desired length of time as described previously with respect to Figure 8. Upon completion of the treatment cycle, the user opens the top hatch 906 to remove the disinfected masks 906.

The four example embodiments of the invention described herein each have different structural features. For example, in some embodiments, the aspects of the system which accommodate equipment being disinfected are separated from the aspects of the system which drive the circulation and heating of air, whereas in other embodiments these aspects of the system are integrated into combined units. In addition, in the first embodiment the -31 -system is scalable by adding further treatment modules, whereas in the second embodiment the system is scalable not only by adding an extension module but also by varying the volume of that extension module. Notwithstanding these structural differences, the principles of operation are common to all embodiments described herein, and it should be understood that any principles of operation described in relation to one embodiment can be applied equally to another embodiment, or combined with any principles of operation described with respect to another embodiment.

The four example embodiments of the invention all employ air recirculation. However, it should be understood that the modular disinfection system described herein (that is, a system comprising a treatment module (having a treatment space for receiving items to be disinfected) and a connected an air circulation module (comprising means for circulating air) with an air flow path between them for heated air) could equally be provided without employing recirculation of air. In this case, air may be extracted from the surroundings of the system via an external air inlet of the air circulation module, which heats the air and drives the air into the treatment module. Once the heated air has passed into the treatment space to heat the items being disinfected, the air is extracted from the treatment module back into the air circulation module and is expelled via an external air outlet into the surrounding environment. In this example, a filter may be provided at the air outlet to prevent pathogens being expelled from the system into the surrounding air.

The present invention is particularly suitable for use with face masks potentially infected with the SARS-CoV-2 virus. Hot air inactivates SARS-CoV-2 because maintaining SARS-CoV-2 at a high temperature for a period of time denatures both the lipid membrane encasing the virus as well as the RNA inside. In particular, inactivation of SAR-CoV-2 is achieved by exposing SARS-CoV-2 to a temperature of 70°C for 30 minutes. N95 masks that use a polypropylene electret layer can withstand 70°C for up to 24 hours without sustaining damage that would make the masks ineffective. Thus, the present invention can be used to provide a hot air disinfection treatment at 70°C for 30 minutes for N95 masks to disinfect the masks from SARS-CoV-2 without damaging the masks. Therefore, the present invention is particularly well suited for use in the COVID-19 pandemic where use of N95 masks is widespread, and so where there is a need to disinfect N95 masks that are potentially infected with SARS-CoV-2. Disinfecting masks rather than disposing of masks after each use reduces waste while also reducing burdens on mask production supply chains. In addition, hot air tends to reach parts of the masks that are difficult to access by manual cleaning and as such the disinfection system and methods described above may be more effective than manual cleaning.

-32 -The present invention is also particularly suitable for ameliorating some of the problems set out in the background section above. Embodiments of the invention are compact meaning that many disinfection systems can be distributed throughout a hospital, one on each ward for example, so that disinfection of equipment can be carried out locally to isolate the virus to individual wards and minimising the movement of people and equipment between wards.

The use of the hot air, rather than steam, means that there is no need for a consumable such as a water supply or chemical disinfectant, and also reduces the power requirements (as it requires less power to heat air than water to a given temperature, and evaporation of water is not required). In addition, the use of hot air avoids the need to dry items after disinfection, which would be the case if using steam. These features mean that embodiments of the invention are conveniently portable, meaning disinfection systems can be provided to every community health worker to carry about, which enables the worker to disinfect equipment while travelling between patients. The low power requirements enable the system to be powered from an in-car power supply such as an automobile auxiliary power outlet or USB socket, or from battery power. The portability of embodiments of the invention allows disinfection systems to be easily transported to remote locations in less developed countries. Embodiments of the invention repurpose widely available and cheap equipment such as household hairdryers or other commodity hardware. This means that construction of a disinfection system is cheap and simple so that many such systems can be made available in less developed countries. Embodiments of the invention are scalable allowing them to be easily adapted for different use cases. For example, the base module of the second embodiment is suitable for personal use such as by a community health worker, but can be easily adapted by adding the extension module to increase its capacity and so make the system suitable for use by multiple users such as on a hospital ward.

It will be understood that the invention has been described above purely by way of example, and modifications of detail can be made within the scope of the invention.

Each feature disclosed in the description, and (where appropriate) the claims and drawings may be provided independently or in any appropriate combination. In particular, features described in relation to one embodiment may be provided in combination with features described in relation to any other embodiment.

Reference numerals appearing in the claims are by way of illustration only and shall have no limiting effect on the scope of the claims.

Claims

-33 -Claims 1 A disinfection system comprising: a sealable housing comprising a treatment space for receiving items to be disinfected; means for circulating air; and a heating element; wherein the means for circulating air is arranged to drive a flow of air within the disinfection system along an air flow path comprising: a supply flow path from the means for circulating air to the treatment space; and a return flow path from the treatment space to the means for circulating air; wherein the heating element is situated on the air flow path and is arranged to heat air driven along the air flow path.
2. A disinfection system according to Claim 1, further comprising an air return plenum situated on the return flow path.
3. A disinfection system according to Claim 2, wherein the means for circulating air is arranged to extract air from the air return plenum.
4 A disinfection system according to Claims 2 or 3, further comprising an air flow regulating element situated along the return flow path between the treatment space and the air return plenum.
5. A disinfection system according to any preceding claim, further comprising an air supply plenum situated along the supply flow path.
6. A disinfection system according to Claim 5, wherein the means for circulating air is arranged to output air into the air supply plenum.
7 A disinfection system according to Claim 5 or 6, further comprising an air dispersion element situated along the supply flow path between the air supply plenum and the treatment space.
8. A disinfection system according to any preceding claim, further comprising a partition for separating the supply flow path and the return flow path -34 - 9 A disinfection system according to any preceding claim, wherein the treatment space, the means for circulating air, the heating element, and the air flow path are contained within the sealable housing to form a closed air circulation system.A disinfection system comprising: a treatment module comprising a treatment space for receiving items to be disinfected; an air circulation module comprising means for circulating air; and means for connecting the treatment module and the air circulation module, wherein, upon connection of the treatment module to the air circulation module, an air flow path is provided between the treatment module and the air circulation module; the system further comprising a heating element arranged to heat air circulated by the means for circulating air.11. A disinfection system according to Claim 10, wherein the treatment module further comprises means for connecting to one or more further treatment modules.12. A disinfection system according to Claim 10 or 11, comprising at least one further treatment module, comprising a treatment space, connected to the first treatment module, wherein, upon connection of the further treatment module to the first treatment module, an air flow path is provided between the at least one further treatment module and the air circulation module.13. A disinfection system according to Claim 12, comprising an air supply plenum shared across the treatment modules and situated on a supply flow path between the circulation module and the treatment spaces of the treatment modules.14. A disinfection system according to Claim 13, comprising a resistive element shared across the treatment modules and situated on the supply flow path between the shared air supply plenum and the treatment spaces of the treatment modules.15. A disinfection system according to any of Claims 12 to 14, comprising an air return plenum shared across the treatment modules and situated on a return flow path between the treatment spaces of the treatment modules and the air circulation module.16. A disinfection system according to Claim 15, comprising a resistive element shared across the treatment modules and situated on the return flow path between the treatment spaces of the multiple treatment modules and the shared air return plenum.-35 - 17. A disinfection system according to any of Claims 10 to 16, wherein the treatment module(s), the air circulation module, and the air flow path form a closed air circulation system.18. A disinfection system according to any of Claims 10 to17, wherein the treatment module(s) is/are expandable and collapsible, thereby to vary the volume of the treatment space(s).19. A disinfection system according to Claim 18, wherein the treatment module comprises a double-walled exterior surrounding the treatment space.20. A disinfection system according to any preceding claim, further comprising an insulating material arranged to prevent heat loss from the treatment module.21. A disinfection system according to any preceding claim, further comprising means for sealing the treatment chamber(s) while an item is being disinfected.22. A disinfection system according to any preceding claim, further comprising at least one temperature sensor for measuring the temperature within the treatment chamber(s).23. A disinfection system according to any preceding claim, further comprising means for receiving user input to select a temperature and/or time period setting for a disinfection cycle.24. A disinfection system according to Claim 22 and 3, further comprising means for controlling the operation of the means for circulating air and the heating element in dependence on the sensor measurements and the user input.25. A disinfection system according to any of Claims 22 to 24, further comprising a timer configured to count the time for which the temperature within the treatment chamber(s) is at or above the user selected temperature.26. A disinfection system according to any of Claims 22 to 25, further comprising means for unsealing the treatment chamber(s) when treatment chamber has been at or above the a user selected temperature for a user selected time.27. A disinfection system according to any preceding claim, further comprising means for storing a temperature and/or time setting for a disinfection cycle.-36 - 28. A disinfection system according to Claim 27, wherein the stored temperature and/or time setting corresponds to a particular pathogen and/or item to be disinfected.29 A disinfection system according to any preceding claim, further comprising means for providing information to the user, the information relating to: a temperature within the treatment chamber(s); the temperature of a surface of the system; and/or a length of time at which the temperature within the treatment chamber(s) has been at or above a temperature.30. A disinfection system according to Claim 29, wherein the means for providing information to a user comprises a display and/or a thermochroic indicator.31. A disinfection system according to any preceding claim, further comprising a support within the treatment chamber(s) for holding items to be disinfected in a spaced configuration.32. A disinfection system according to Claim 31, wherein the support is arranged to hold items in a spiral configuration.33. A disinfection system according to any preceding claim, further comprising an air filter arranged to filter air circulated by the means for circulating air.34. A disinfection system according to any preceding claim, further comprising means for connecting the system to an automobile auxiliary power outlet.35. A disinfection system according to any preceding claim, wherein the means for circulating air and/or the heating element are repurposed from commodity hardware, preferably from a hairdryer or a fan oven.36. A disinfection system according to any preceding claim, for use in disinfecting items potentially infected with SARS-00V-2.37 A disinfection system comprising: a sealable housing comprising a treatment space for receiving items to be disinfected; a fan having an air outlet and an air inlet; an air supply flow path between the air outlet and the treatment space for supply of air from the fan to the treatment space; -37 -an air return flow path between the treatment space and the air inlet for return of air from the treatment space to the fan; and a heating element for heating air within the system.38 A disinfection system comprising: a treatment module comprising a treatment space for receiving items to be disinfected; and an air circulation module comprising a fan for circulating air within the system; wherein the treatment module and the air circulation module are attachable to and detachable from one another, and; wherein, upon attachment of the treatment module to the air circulation module, an air flow path is provided between the treatment module and the air circulation module.39 A method of disinfecting an item, comprising: circulating air along an air flow path, the air flow path comprising a supply flow path and a return flow path, the circulating comprising: supplying, along the supply flow path, air from a means for circulating air to a treatment space within which the item is located; returning, along the return flow path, air from the treatment chamber to the means for circulating air; and heating the air circulating along the air flow path.