WO2006131720A1

WO2006131720A1 - Uv-radiation virus deactivation unit

Info

Publication number: WO2006131720A1
Application number: PCT/GB2006/002063
Authority: WO
Inventors: John James
Original assignee: Medi Uv Hold Ltd
Priority date: 2005-06-06
Filing date: 2006-06-06
Publication date: 2006-12-14
Also published as: GB2427113A; GB0511474D0; EP1907019A1; GB2427113B

Abstract

A virus deactivation unit comprising a body defining a chamber for location of an item to be cleansed, wherein the chamber comprises a plurality of ultraviolet light sources configured to minimize shadowing of UV light over the majority of the surface of the item in use.

Description

UV-RADIATION VIRUS DEACTIVATION UNIT

The invention relates to a unit for cleansing items such as electronic equipment and the like. The invention is particularly adapted for cleansing items used in hospital and in particular for deactivating viruses or other organism containing RNA or DNA which might be present on such items.

It is known to use ultraviolet light to deactivate viruses for example in water treatment whereby water is passed through a region of ultraviolet light in the cleaning process. This requires the complication of the water to be pumped through the region of UV and for the section to be sufficiently long to ensure deactivation of all viruses in the water. In order to cleanse solid objects, it is known to provide hand-held units to shine ultraviolet light on items in order to cleanse them by deactivation of viruses. However, use of such hand-held units requires the user to take considerable health and safety measures to prevent harm both to themselves and anybody else within the vicinity. Accordingly, typically protective clothing including gloves and goggles are worn by a user in order to reduce the risk of excess exposure to ultraviolet radiation. Moreover, it cannot be determined accurately how much of the surface of the item has been irradiated in such a hand-held operation.

An object of the invention is to provide an improved unit for enabling virus deactivation on items, particularly static, three dimensional solid items, such as electrical equipment and even larger items such as hospital beds. Another object of the invention is to minimise the number and/or optimise the efficiency of UV exposures of an item to ensure complete deactivation over the entire surface of the item. A further object of the invention is to reduce the risk of exposure to users of excess ultraviolet radiation.

Accordingly, an aspect of the invention provides a virus deactivation unit comprising a body defining a chamber for location of an item to be cleansed, wherein the chamber comprises a plurality of ultraviolet light sources configured to minimise shadowing of UV light over the majority of the surface of the item in use. Preferably, the unit achieves UV radiation coverage of over 90%, and more preferably over 95%, of the surface of an item in a single exposure of UV to the item in the unit, and preferably this is achieved even when the item is stationary in the unit.

Preferably, the unit has a moveable closure and is entirely closed in use to prevent egress of UV radiation from the unit. Beneficially therefore a user does not need to wear protective clothing when using a unit according to the invention.

Other aspects and features of the invention are set out in the claims hereto.

Embodiments of the invention will now be described by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a first embodiment of the invention, Figure 2 is a schematic end view of the interior of the unit shown in figure 1,

Figure 3 is a schematic side view of three of the walls forming part of the unit shown in figure 1,

Figure 4 is a schematic side view of part of the door for the unit shown in figure 1,

Figure 5 is a schematic block diagram of some of the electronic circuitry used in the unit shown in figures 1 to 4.

Figure 6 is a schematic view of a wall of a unit comprising an array of lamps, and

Figure 7 is a schematic side view of another form of reflector panel.

Referring to the figures there is shown a unit 10 according to the invention comprising a main body 12 having closure in the form of a door 14, wherein the unit 10 comprises a chamber 16 for location of items to be cleansed. The unit 10 has a width W, depth D, and height H (as shown in figure 1) which are preferably in the order of a meter each in one form of the unit thereby enabling insertion of solid three-dimensional items such as electrical equipment into chamber 16. In other forms the dimensions are considerably larger and, for example, the width, depth and height might be up to three meters thereby enabling insertion of larger items, such as hospital beds into unit 10. Referring to figure 1, it can be seen that door 14 comprises a hinge 18 and a handle 22 such that it is moveable between an open and closed position. Preferably, a seal 20 is provided at the interface of the door 14 and body 12 to prevent egress of ultraviolet light in use when the door is closed. Preferably, this comprises an outer UV stable material and can comprise magnetic strips to hold the door 14 against the body 12. Other latching mechanisms can also be provided to hold the door 14 in a closed position.

The front of the door 14 further comprises a user interface 23, for example comprising a UV effectiveness display 24 which in this embodiment comprises one LED per ultraviolet light source contained within unit 10. In other forms, a UV effectiveness display 24 can be provided having a numeric output of the numbers of lamps which are in use. Beneficially therefore a user is able to determine whether or not the unit 10 is operating at maximum efficiency and whether or not any individual ultraviolet light sources require replacing. Preferably the location of any blown UV tubes is indicated by the display. The user interface 23 further comprises a start button 26, a timer display 28, an instructions panel 30, which in one form is an interactive user interface with a central controller, and a main power on/off light 32.

Referring to figure 2, the top, bottom and side walls 34 of body 12 are shown with the door 14 and rear wall removed for clarity. From this end view of the body 12, chamber 16 can clearly be seen as defined in the centre of the unit. Each wall 34 of the unit 10 carries a panel 36 for supporting a reflector panel 38 positioned between the wall 34 and an array 39 of ultraviolet light sources 40, in this case a number of tubes. In this embodiment each wall 34 carries eight UV lamps 40, so that forty eight lamps are provided in chamber 16. A screen is provided in front of the ultraviolet tubes 40 to prevent damage by an item inserted into chamber 16. Preferably the screen 42 comprises a wire mesh. Supports 44 are provided to hold the mesh 42 away from the tubes. In one form, five supports 44 are provided in the base of the unit 10, a single support 44 can be provided to hold the top layer of mesh and possibly a single support 44 is provided in the rear wall similarly to support the mesh 42. In this embodiment, the tubes 40 are aligned above or adjacent one another on the associated wall 34. In other forms, combinations of staggered arrays of UV light sources 40 can be positioned on a wall 34 in order to minimise shadowing of an item placed in chamber 16. For example if the depth d is larger than the width w or height h of the unit 10, longer tubes might be used on the side top and bottom walls than on other end wall and door or a staggered array of overlapping or interdigitated tubes might be appropriate as shown in Figure 6.

The arrangement of the support panels 36, tubes 40 and supports 44 can be seen also in figure 3 wherein the side walls 34 are removed for clarity. Also shown in figure 3 is an extension of the walls at the open end adjacent to the door in the form of a lip 46 which preferably extends into the door when closed thereby helping to prevent egress of ultraviolet light from the chamber 16 when in use. Preferably lip 46 protrudes from all four edges of the entry to chamber 16 thereby to engage the door 14 when closed, along the entire circumference of the interface of the door 14 with the unit 12.

The door 14 is shown in greater detail in figure 4 wherein one edge of the door is removed for clarity. As is shown, the door 14 comprises a hinge 18, an array of ultraviolet light tubes 40 mounted on a support panel 36 which carries a reflective panel (38 not shown). Behind the support panel 36 there is space between the wall of the door and the panel 36 for the ballast for each of the ultraviolet lights 40.

Referring to figure 7 there is shown a form of reflector panel 38 having a different configuration to that shown in figure 2. In this embodiment, the reflector plate provides a recess behind each lamp 40 which rather than simply being a two sided V shape, is a three sided truncated V shape. Preferably the base indicated at 38 b has a width approximately twice the diameter of lamp 40. Similarly, preferably the depth of the recess indicated by reference to panel 38 d is in the order of or greater than the diameter of the light source 40. In one form, the unit 10 according to the invention can be constructed about a tubular framework forming a cube or other six sided structure having tubes along each of the corners. Preferably, the tubes have a square cross section and enable folding of a blank of

metal sheet around the frame thereby to form the main body 12. Accordingly, in one form, a blank can be formed having all of the walls 34 for the main body 12 cut to a single blank whereby folding of the blank about the framework enables formation of the outer wall which can then be closed through welding along for example two edges between the top wall and the end wall and one side wall and similarly between the bottom wall and the end wall as well as one side wall. Preferably, the walls are joined along edges by tig welding. Accordingly, a light tight box is ideally formed for use in the virus deactivation unit.

By mounting the support panels 36 in a removeable manner within units 10, it is possible to place the ballast 48 for each of the lights behind 40 each of the panel 36. Alternatively, the top bottom and side wall support panels 36 might be more permanently positioned and the support panel 36 in the rear wall might be removable and thereby enable positioning of ballast for some or all of the UV light sources 40 within the main body 12 to be located behind a support panel 36 positioned (removeably) against the rear wall 34. Preferably, the reflector panels 38 are detachably mounted on the support panels 36 for example using a nut and bolt arrangement or a magnetic arrangement.

Referring to figure 5, there is shown a schematic diagram of some electronics for operating the unit 10 according to the invention. In figure 5 there is shown a power supply 52 connected to an overall array 64 of light sources 40 represented schematically by a single tube 40 having an associated ballast 60. Preferably an LED 62 is provided for each lamp 40 forming part in an LED array in display 24 shown in figure 1. The start button 26 is shown schematically in figure 5 at switch 58 and a timer 56 is also provided which is linked to timer display 28 on the door 14 shown in figure 1 thereby to indicate to a user the length of exposure of an item being cleansed. Preferably a door proximity sensor 54 is also provided which preferably acts to prevent operation of the unit, that is exposure of an item to ultraviolet radiation, unless it is determined that the door 14 is properly closed. In use, a user loads an item to be cleansed into chamber 16. The item can be mounted directly onto the mesh or on a knife edge support for example in the form of a triangular structure having minimal contact with the item and the base mesh 42 in chamber 16. The user then closes door 14 ensuring a close fit of the door 14 with body 14 preferably through overlap of lips 46 with the door and/or due to contact of seal 20. The user ensures that the power on light 32 is lit then starts the unit using start button 26. In one form, the unit 10 is configured automatically to provide a single exposure of say 30 seconds, or other predetermined time, to each item upon activation of the unit by depression of start button 26. In another form, a user interface to an electronics control device can be provided enabling the user to determine the length of exposure. In the circumstances of automatically timed exposure, power is then supplied to each of the lamps 40 within the unit and an individual LED 24 light according to the functionality of those lights 40. Assuming that all lights are operational (or another number or percentage of the overall number of lights are functional beyond a predetermined limit to ensure satisfactory cleansing), the timer 56 counts down the predetermined exposure time such as 30 seconds and this is displayed at timer display 28. Upon completion of the predetermined exposure, the user opens the door 14 and, preferably using a sterilised tool, moves the item being cleansed to a different position to effect radiation of the entire surface of item. The user then closes door 14 again and, in one embodiment, the unit is configured automatically to repeat a second exposure for the predetermined time limit again indicating the number of lamps and the time for the exposure on the relevant display. Alternatively the user presses start button 26 again to commence cleansing.

After completion of the second exposure, the user is able to remove the cleansed item and repeat the cleansing procedure on a second item.

In the circumstances that the door proximity sensor is not closed or other safety features indicates a problem, then the unit 10 is configured not to allow activation of the lamps thereby preventing accidental leakage of radiation of ultraviolet light from the unit 10.

Similarly, if an event occurs during an exposure such as opening of the door 14 or one or more lamps blows during the exposure, possibly effecting a reduced level of activity of the overall array of lamps below a predetermined limit whereby it is deemed that the decontaminating exposure would not be of a satisfactory level, the unit 10 ceases further exposure and provides a warning to the user for example through display 28.

Claims

1. A virus deactivation unit comprising a body defining a chamber for location of an item to be cleansed, wherein the chamber comprises a plurality of ultraviolet light sources configured to minimise shadowing of UV light over the majority of the surface of the item in use.

2. A unit according to claim 1, in which the UV light source configuration achieves UV radiation coverage of over 90%, and more preferably over 95%, of the surface of an item in a single exposure of UV to the item in the unit.

3. A unit according to claim 1 comprising a moveable closure which is closable in use to prevent egress of ultraviolet light.

4. A unit according to claim 3 comprising a lip located at the interface between the closure and the rest of the unit which lip helps prevent egress of ultraviolet light in use.

5. A unit according to claim 3 or 4 comprising a seal locatable between interface of the closure and the rest of the unit thereby to prevent egress of ultraviolet light in use.

6. A unit according to claims 3, 4 or 5 comprising a sensor for determining if the closure is closed thereby enabling prevention of activation of the ultraviolet light sources in the event that the closure is in an open position.

7. A unit according to any preceding claim wherein chamber is defined by a plurality of walls, each wall having at least one ultraviolet light source.

8. A unit according to claim 7 wherein each wall comprises more than 5 ultraviolet light sources.

9. A unit according to any preceding claim wherein the chamber is defined by 6 walls.

10. A unit according to any preceding claim wherein more than 40 ultraviolet light sources are provided.

11. A unit according to any preceding claim wherein a reflector is provided for an ultraviolet light source to direct light radiated from the source into the chamber.

12. A unit according to claim 11 wherein a panel of reflectors is provided for an array of ultraviolet light sources.

13. A unit according to claim 12 wherein the panel of reflectors is removable from the unit.

14. A unit according to any preceding claim comprising a removable panel for supporting an ultraviolet light source within the unit in use but allowing removal thereof for repair.

15. A unit according to claim 14 wherein the removable panel enables removal of one or more of a light source, a reflector panel, and a protective screen.

16. A unit according to any preceding claim comprising a protective screen between an ultraviolet light source and the centre of the chamber.

17. A unit according to claim 16 wherein a plurality of protective screens is provided and preferably the protective screens form a cage defining chamber within the unit.

18. A unit according to claims 15, 16 or 17wherein the protective screen comprises a mesh preferably a wire mesh.

19. A unit according to any preceding claim comprising a user interface providing one or more of the following: an indication of the number of operable ultraviolet light sources within the unit, an individual indication of the operability of each light source within the unit, an indication of the length of exposure during use of the unit, a warning indicator to indicate to the user of any irregularity such as the closure being in an open state during an intended decontamination exposure.