GB2530384A - Sterilisation device and method - Google Patents

Abstract

The present invention relates to a device 1 for sterilising an article 2, the device comprising means for emitting a germicidal light and means for sweeping the emitted light over the article. The device may comprise a base 3 and a casing 4, wherein the casing is slidable in the longitudinal direction of the base. Preferably the germicidal light is an ultraviolet (UV) light or is plasma-based or plasma-generated. The device may further comprise a means for reflecting germicidal light towards the article and means for detecting the article and/or the presence of an object on the article. Also claimed is a method of sterilising an article 2 comprising the steps of directing germicidal light onto the article using the device 1 and sweeping the emitted light over the surface of the article.

Description

STERILISATION DEVICE AND METHOD

The present invention relates to a sterilisation device, more particularly a device for sterilising articles using a germicidal such as ultraviolet (TJV) light.

Radiation sterilisation has been used for many years to kill microorganisms in a variety of applications, for example in the food industry and for medical sanitisation, Both ionising and non-ionising radiations are available. lonising radiation uses short wavelength, penetrating high intensity radiation, whilst non-ionising radiation uses longer wavelength and non-penetrating lower energy. Thus, non-ionising radiation, such as UV radiation (UVR) can be used for safely sterilising surfaces, As mentioned above, this type of sterilisation technology has been widely used in the food and medical fields, where the prevention of infection is a high priority target. A typical infection pathway is for example where a medical practitioner examines a contaminated patient and enters data into a computerised system, thereby transfethng bacteria and germs onto the computer input devices (keyboard, mouse and/or touch screen). The contaminated devices are then handled by the same or different medical practitioner and spread to the next patients. Similarly, in a meat counter, the counter assistant will cut, weight and label a meat product thereby contaminating the cutting device, the scale and the printing device. The risk of infection is not limited to the food and medical fields, and viruses, bacteria, mould and germs can be found in research facilities, schools and offices, or simply at a cash point or public telephone, Several radiation sterilisation methods have been proposed. Typically, the object to be sterilised is placed into a sterilisation chamber and exposed to TJV light for a set time period, Such a chamber, as described for example in US 2008/00674 17, can be bulky and unsuitable for facilities where no or limited storage space is available as the chamber can only sterilise one object at a time. Alternatively, the sterilisation process would be time consuming where a large number of objects (for example computer keyboards in an office) were to be sterilised in turn, in addition, the object, in this case a keyboard, must be unplugged and moved into the chamber and cannot be utilised during the sterilisation period. This could be appropriate in facilities such as offices and schools, where sterilisation could be carried out overnight; however, it is not suitable for hospitals or other facilities where a 24 hour access to the computer system is required, Desktop solutions have been proposed such as modified keyboards with an integrated cover as exemplified in 0B2446387. Although these devices are less bulky than the sterilisation chambers discussed above, purchase, repair and/or replacement of these all-in-one devices can be expensive. In addition, in its open configuration, the cover will either be between the user and the computer screen or occupying desk space.

It is an object of this invention to mitigate problems such as those described above.

According to a first aspect of the invention, there is provided a device for sterilising an article, the device comprising means for emitting a germicidal light and means for sweeping the emitted light over the article.

Thus, the invention seeks to provide a device capable of efficiently sterilising, sanitising and or disinfecting a variety of articles such as keyboards, desktops and computer screens and is therefore versatile. The device can simply be fitted to the article to be sterilised and need not be removed when the article is being used. An important distinction over known sterilisation devices is that the device according to the present invention is capable of sweeping the germicidal light across the surface of the article to be treated. Thus, the entire surface of the article can be homogeneously sterilised. In addition, the article can be exposed to germicidal light when required and the germicidal light source can simply be positioned into a rest position when the article is being used. Further advantages will be described below with reference to

specific examples.

In a preferred embodiment, the device further comprises a base and a casing for containing the means for emitting a germicidal light, wherein the casing is slidably connected to the base.

The base and casing provide enclosed spaces capable of containing the various elements of the present invention so that the contamination of such elements by bacteria, viruses, mould and germs is minimised or prevented.

Preferably, the base is an &ongate base and the casing is slidable along the longitudinal direction of the base. This configuration is advantageous to sterilise elongate or substantially rectangular articles such as keyboards, desktops and screens so that the entire surface can be homogeneously sterilised, The elongate base can neatly fit along one of the longitudinal sides of the article so that minimal desk space is required.

Preferably, the casing is pivotable relative to the base from a use position substantially perpendicular to the base to a storage position substantially parallel to the base. In the use position, the casing is positioned such that the germicidal light is directed to the surface of the article to be sterilised. In the storage position where the casing is substantially parallel to the base, the casing and the germicidal light source are protected and the device can be stored in a compact and safe manner. Additionally or alternatively, the casing is pivotable in the radial direction of the base. This enables the user to accommodate and sterilise articles of various shapes and sizes.

Preferably, the casing comprises means for reflecting germicidal light towards the article.

This reflector focuses and redirects the germicidal light towards the article to be sterilised so that there is minimal or no loss of germicidal light.

The preferred distance between the surface of the article to the germicidal light source is equal or less than about 0.75 inch (19.05 mm) and the preferred distance is about 0.5 inch (12.7 mm). The inventor has observed that a greater distance between the light source and the article results in loss of germicidal light firstly because of the distance itself, but also because of interfering outside light into the germicidal light beam. In addition, although germicidal light, such as UV-C light, is not harmful to the user at the applied intensity, exposure is preferably avoided and the preferred distance prevents any germicidal light leakage. At about 0.5 inch (12.7 mm), the above advantages are achieved and so is optimum germicidal efficiency.

Preferably, the device further comprises means for detecting the presence of an object on the article. The object can be the user's hand (e.g. if the user starts typing) or simply an obstacle (e.g. an object accidentally falling on a keyboard). The detector may act as a safety switch such that the sterilisation process is halted and/or cannot be initiated until the object is removed. An audio and/or visual alarm can be provided to signal the presence of an obj ect on the article.

Preferably, the device further comprises means for detecting the article, more particularly to detect that the presence of the article, its correct installation and/or positioning relative to the sterilisation device. The detector may simply be a tab which is retractable when the article is correctly positioned relative to the sterilisation device. The detector may act as a safety switch such that the sterilisation process is halted and/or cannot be initiated until the article is correctly installed (e.g. tab in the retracted position). An audio and/or visual alarm can be provided to signal incorrect positioning.

Preferably, the device further comprises a control unit. The control unit enables the adjustment of parameters such as sterilisation process start and/or stop, speed of sweep, number of sweeps, detectors, audio and/or visual signals, and any other device parameters, The control unit is preferably a reprogrammable chip, which enables the manufacturer and/or user to set the required parameters. Preferably, the control unit is located within the device to minimise and/or avoid contamination or damage. Additionally or alternatively, the device may comprise a control panel to set the device parameters.

Preferably, the device comprises a plastic material, For example, the base and/or casing can be made of moulded plastic, Preferred plastic materials include but are not limited to Acrylonitrile Butadiene Styrene (ABS), Styrene Acrylonitrile Resin (SAN), Acrylonitrile Styrene Acrylate (ASA), Nylon, High Impact Polystyrene (HIPS), Polypropylene (PP), and Polycarbonate (PC). The preferred material is ABS. Plastic materials are preferred for ease of manufacture, versatility and lightness. Alternatively, the base and/or casing could be made of metal, such as stainless steel, for robustness but lighter materials are preferred.

Preferably, the device comprises one or more antibacterial agent. In a preferred embodiment, the base and/or casing are made of a plastic material which comprises an antibacterial agent. For example, the material is a polymer mixed or blended with one or antibacterial agents before moulding, Thus, the risk of infection is further minimised, Examples of such materials include but are not limited to Biomaster1 612 and ASA KibilacThI PW-957.

BiomasterThi 612 is an antibacterial additive which slowly releases silver ions, thereby inhibiting bacterial growth for a prolonged time period. This antibacterial additive carl be processed at temperatures up to 600°C without losing its antibacterial properties and is particularly suitable for blending in ABS and/or SAN.

Preferably, the device comprises a heat resistant material and/or a UV resistant material. A preferred material is ASA Kibilac'TM PW-978B, The germicidal light is preferably UV light, preferably IJV-C light. Preferably, the IJV light is in the range of about 200 nm to about 280 nm, more preferably about 254nm, most preferably 253.7 nm and 260nm, This is because optimum antibacterial efficiency has been observed when the IJV light source has a peak at 260nm. Nonetheless germicidal lamps at 253,7 nm are widely available and also efficient. Any numerical range provided within the context of the invention includes the lowermost and uppermost numerical values, Preferably, the light emitting means is a lamp. The lamp is preferably tubular for optimum light emission across the article(s). The preferred wattage is 4 Watts per lamp and preferably the device comprises three lamps, Examples of preferred lamps emitting germicidal light include but are not limited to mercury vapour lamp and LED-type IJY lamps, The germicidal light may alternatively be a plasma-generated light, In other words, the present invention can incorporate plasma sterilisation technology, for example oxygen plasma, which is a safe and environmentally friendly alternative to traditional cleaning methods, The active species in the oxygen combined with VUV energy creates a chemical reaction with the surface contaminants, resulting in their volatilization and removal from the reaction chamber.

According to a second aspect of the invention, there is provided a method for sterilising an article comprising the steps of directing germicidal light onto the article using a device as described in any one of the preceding paragraph and sweeping the emitted light over the surface of the article.

Preferably, the light is swept at a speed of from 400mm/minute to 500mm/minute. For example, a typical sweep time over the surface of a standard computer keyboard is 45 -60 seconds, preferably 60 seconds.

The invention will be frirther described with reference to the drawings and figures, in which figure 1 is a schematic representation of a sterilisation device according to the present invention in use with a computer keyboard; figure 2 is a schematic representation of the sterilisation device of figure 1, shown without the computer keyboard; figure 3 is a schematic representation of a second sterilisation device according to the present invention in use with a touch screen tablet, such as an iPadTM.

figure 4 is a schematic representation of the sterilisation device of figure 1 further comprising side tabs; figures SA and 5B are schematic representations of the sterilisation device of figure 1 further comprising a front clip; figures 6A and ÔB are partial schematic representations of a base and a casing for a sterilisation device of figure 1; figures 7A to 7E are partial schematic representations of a casing for a sterilisation device of figure 1; figures 8A and 8B are partial schematic representations of a sweeping mechanism for a sterilisation device of figure 1; figure 9 is a partial schematic representation of a cross-section of the sterilisation device of figure 1; figure 10 is a schematic representation of a third sterilisation device according to the present invention; figures 1 IA and 1 lB are partial schematic representations of a base for a sterilisation device of figure 10; figures 12A and 12B are schematic representations of a fourth sterilisation device according to the present invention shown with and without the article to be treated; figures 13A and 13B are schematic representations of the sterilisation device of figures 12A and 12B in use with a computer mouse; figures 14A and 14B are partial schematic representations of a sterilisation device according to the present invention; figure 15 is a schematic representation of a sterilisation device according to the present invention in use with a display screen, such as a computer screen; figures 16 and 17 are schematic (perspective front and back) representations of a fifth sterilisation device according to the present invention, in a working configuration; figure 18 is a schematic representation of the sterilisation device of figure 16 in a rest or storage configuration; figure 19 is a schematic representation of the sterilisation device of figure 16, shown without its base casing; figure 20 is a schematic representation of the sterilisation device of figure 19, shown without its lamp casing; figure 21 is a schematic representation of the sterilisation device of figure 16 shown with a computer keyboard; figures 22A to 22C are schematic representations of the sterilisation device of figure 16 comprising a keyboard positioning means; figure 23 is a schematic representation of the sterilisation device of figure 16 shown with a laptop computer; and figures 24 and 25 are diagrams showing an electronic system for a sterilisation device according to the present invention.

Referring to figure 1, there is illustrated a device for sterilising an article 2, the device I comprising means for emitting a germicidal light and means for sweeping the emifted light over the article. The device I comprises a base 3 and a casing 4 for containing the means for emitting a germicidal light. In figure 1, the article 2 is a computer keyboard; in figure 3, the article is a touch screen tablet, such as an iPadTM, and in figure 14, the article is a display screen, such as a computer screen.

The invention will be described with respect to the sterilisation of a computer keyboard 2.

However, it is understood that the invention can be applied to other articles such as a desk top, fixed and mobile telephones, keys, computer mouse, calculators, office stationary and the like.

Similarly, the invention can be applied in any environment requiring sanitization, including offices, food manufacturing and catering facilities, healthcare facilities, cash points and tills, restrooms and the like.

Turning back to the sterilising device of figure 1, the base 3 comprises an elongated hollow housing 3A, which is placed along a side of the computer keyboard 2. In the position as shown in figure 1, i.e. with the keyboard 2 between the user and the device 1, the device 1 does not hinder access to the keyboard 2. A keyboard support 3B extends along the longitudinal direction of the housing 3A to support at least part of the lower surface of the keyboard 2. In this embodiment, the upper surface of support 3B is slightly angled relative (i.e. not parallel) to its lower surface so that the keyboard surface to be sterilised is substantially parallel to the light source.

With reference to figure 3, the length of the housing 3A may be adjusted to fit articles of various sizes, such as touch screen devices (e.g. iPadTM), Alternatively or additionally, the device I comprises means for securing and/or correctly positioning the article 2 relative to the device L In the embodiment of figures 3 and 4, the keyboard support 3B comprises width retainers, which are two side tabs SA extending substantially perpendicularly from the upper surface of support 3B. The tabs 5A are slidable along a guiding recess SB, so that the article 2 can be securely positioned between the two tabs 5A. The guiding recess SB is substantially parallel to the housing 3A. In an alternative embodiment, the side tabs SA are slidable within a guiding recess (not shown) within the housing 3A.

Alternatively or additionally, the keyboard support 3B comprises depth retainers, which is an arm extending substantially perpendicularly from the housing 3A so that the arm's length can be adjusted to fit the depth of the keyboard 2. The keyboard 2 is secured between the housing 3A and the front tab 6 extending substantially perpendicularly from the distal end of the arm, In an alternative embodiment, the front tab 6 extends substantially perpendicularly from the support 3B and may be slidable within a guiding recess (not shown) within the support 3B.

The housing 3A of the base 3 is substantially hollow so that it provides a housing for the sweeping means, control unit and other internal elements and a support for switches, electrical leads and other external elements as illustrated for example in figures 9 and 10.

In this embodiment, a control unit 7 is housed within the base 3. The control unit enables the adjustment of parameters such as sterilisation process start and/or stop, speed of sweep, number of sweeps, detectors, audio and/or visual signals, and any other device parameters such as those relating to the motor, In this embodiment, the control unit is a reprogrammable chip, which enables the manufacturer and/or user to set the required parameters.

The device I comprises means for detecting the presence of an object on the keyboard 2.

The object can be the user's hand (e.g. if the user starts typing) or simply an obstacle (e.g. an object accidentally falling or left on the keyboard 2). The detector (not shown) acts as a safety switch such that the sterilisation process is halted and/or cannot be initiated until the object is removed from the keyboard 2. Audio and visual alarms are provided to signal the presence of an object on the keyboard 2.

The device 1 comprises means for detecting the presence of the keyboard 2, its correct installation and/or positioning relative to the sterilisation device I. The detector (not shown) can be a retractable tab located on the base 3, on the housing 3A or the support 3B, The detector acts as a safety switch such that the sterilisation process is hailed and/or cannot be initiated until the keyboard is correctly installed (i.e. tab in the retracted position). Audio arid visual alarms are provided to signal the presence of an object on the keyboard 2.

The germicidal light source is a TJV lamp 9, preferably LTV-C lamp between about 200 and 280 nm, and preferably at around 254 nm or 2GOnm for optimum efficiency. Preferred lamps are mercury vapour lamps. Preferred wattage is 4 Watts per lamp. Preferred number of lamps is one to three, most preferably three. The shape of the germicidal light source or lamp can vary according to the shape of the article to be sterilised. In this embodiment, the lamp casing 4 is comprises an elongate member to accommodate the tubular UV lamps. The elongate shape of the casing 4 combined with the shape of the base 3 allows optimum sterilisation of substantially rectangular articles, such as keyboards, touch screen devices, screens, mobile telephones and the like.

The IJV-C lamp(s) are partially surrounded by lamp casing 4. The lamp casing 4 shields the user from UV light and directs the UV light beam towards the keyboard 2, for example by means of a reflector (not shown). For example, reflectors with a reflection capacity of from 60 to 90% have been found to be advantageous.

With reference to figure 10, only the light emitting portions of the UV lamp are exposed.

In other words, the electrical connections are housed within closed sub-compartments 26 in the lamp casing 4 so that contamination of small parts is minimised. The casing 4 can comprise an optional UV-transparent window through which the UV light beam traverses to hit the surface to be sterilised, This IJV-transparent window protects the light source from contaminati on, In use, the casing 4 is arranged and located over the surface of the keyboard, so that the UVIamp is at a distance of from 0.75 inch to 0.5 inch 19.05 mm to 12.7mm), preferably 0.5 inch (2.7 mm) from the surface of the article to be sterilised. The casing 3 is positioned such that the surface of the UV lamp is substantially parallel to the surface of the article to be sterilised so that homogeneous sterilisation is achieved, The back of the keyboard 2 is raised by means of the support 3B so that the plane of the keyboard 2 is at a slight angle so as to minimise or prevent the risk of repetitive strain injury to the user, Turning now to the sweeping mechanism, the base 3 comprises a slit 8 along the housing 3A, along which the lamp casing 4 is slidable as shown in figures GA and 6ft More specifically, the external lamp casing 4 is connected to an internal sliding element 27 by a neck U. The neck U is slidable along the slit 8. In this context, the terms "external" and "internal" are used with reference to the housing 3A. A first internal sliding element 27 will be described in further detail below th reference to figures 7 to 9.

The internal sliding element 27 comprises one or more wheels 13A, 13B for sliding long support ribs 16, 17 within the housing 3A. In this embodiment, the sliding element 27 comprises two front wheels 13A positioned substantially parallel to the longitudinal axis of housing 3A for sliding along front support ribs 16 also substantially parallel to the longitudinal axis of housing 3A. There are two front support ribs which, in use, partially surround the front wheels 13A for accurate sliding movement, The sliding element 27 also comprises two back wheels 13B for sliding along back support ribs 17. The back support ribs 17 are also substantially parallel to the longitudinal axis of housing 3A.

The support ribs 16, 17 are formed within the housing 3A, as internal parts, so as to avoid contamination from external viruses, bacteria, mould and/or germs. In addition, the support ribs 16, 17 are preferably integrally formed or moulded with the housing 3A for robustness and ease of manufacture. The housing 3A may comprise additional internal ribs 15 to strengthen the overall housing structure.

With reference to figures 8A and 8B, the sliding element 27 is attached to a belt 19, In this embodiment, the belt 19 is an endless chain which is connected to two rotatable wheels 18 located adjacent each end of the housing 3A so that rotation of the wheel(s) enables the movement of the sliding element 27 in the longitudinal direction of the housing 3A. The motor (not shown) of the sweeping means, and therefore the rotation of the wheels 18 (including direction, speed and timing) is controlled by the control unit 7, which has been (pre-) programmed by the user and/or manufacturer.

The belt 9 may comprise a buffering means, such as a spring 20, to prevent the sliding element 27 from impacting the rotatable wheels 18, thereby minimising the risk of mechanical damage. The sliding element 227 comprises a recess 14 to receive the belt 9.

The base 3, casing 4 and/or sliding element 27 are made from the same or different material, such as a polymer or plastic material. Alternatively, a metal, such as stainless steel, could be used for its robustness, However, plastic materials are preferred because of the ease of manufacture of moulded products. Although stainless steel provides a robust alternative, the resulting device is heavy and more expensive to manufacture and transport. Polycarbon materials were also considered and tested but found to be too brittle for the present application. The material may comprise one or more antibacterial agents, heat resistant material and/or UV-resistant material.

The device 1 may be powered via an electrical power cable 25 from the mains, via a USB cable from the computer or may be battery powered.

Figures 10 to H are provided to describe additional or alternative features for a sterilising device t according to the present invention. The features shown in the figures and described herein can be combined or used independently from each other to produce a device t meeting the requirements of the user.

Figure 10 illustrates an alternative sweeping means mechanism, in which the lamp casing 4 is connected to a sliding element 21 by a neck 12. The neck 12 is arranged and constructed to slide along a slit 8. The slit 8 is substantially parallel to the longitudinal direction of the housing 3A, The sliding element 1 is slidably connected and supported by support bars 22 extending parallel to the longitudinal direction of the housing 3A, The neck 12 is attached to and/or sits onto a belt 24. The belt 24 (for example an endless flat belt) is connected to rotatable wheel 23 so that rotation of the wheel 23 enables the movement of the sliding element 21 along the longitudinal direction of the housing 3A.

In the present invention, the base 3 and casing 4 are constructed and arranged so as to minimise the risk of contamination by surrounding viruses, bacteria, mould and/or germs and small parts and recesses are not included wherever possible. As described above, the base 3 is used to house the sweeping means, control unit and other internal elements. The base 3 can comprise one or two detachable end caps 0 as shown in figures 1 IA and FIB, which in the closed configuration is flush with the distal end of the housing 3A, thereby reducing the number of entry points or surface area for viruses, bacteria, mould and/or germs to deposit and thus minimi sing the risk of contamination.

With reference to figures 12 and 13, the device I is used to sterilise articles 2, in this case a computer mouse 2, laid adjacent the device 1. In this embodiment, the casing 4 is positioned substantially perpendicular to the longitudinal and radial axis of housing 3A. The casing 4 may be pivotable relative to the housing 3A in a clockwise and/or anti-clockwise manner, in a plane substantially parallel to the desk top or support surface, for example so that (1) the casing 4 is substantially parallel (0) to and along the housing 3A (in a storage position); (2) the casing 4 is perpendicular (90) to the housing 3A (as illustrated in figure 13 B); the casing 4 is substantially parallel (180) to the housing 3A and extending in the longitudinal direction of the housing 3A to sterilise articles such as lab books, mobile telephones, keys, laid by the device 1. Similarly, the casing 4 may be pivotable relative to the housing 3A so that it is no longer parallel to the desktop or support surface. This feature allows the sterilisation of articles of different shapes and/or dimensions.

In use, a keyboard is placed onto the support 3B so that the housing 3A of the sterilisation device 1 sits against the top edge of the keyboard 2. The lamp casing 4 is positioned adjacent the keyboard 2 in its rest configuration, i.e. on the left hand side or the right hand side of the keyboard 2, so that the user can still have access to the keyboard 2. The width retainers 5A are -In I.3 moved along guiding recess SB to trap the keyboard 2 sideway and the front retainer 6 is adjusted to trap the keyboard 2 between the retainer 6 and the housing 3A, The sterilisation process can be initiated either by the user (e.g. by pressing the switch) or S automatically (e.g. after a period of inactivity). The pre-programmed control unit 7 controls the speed, number and timing of rotation of wheels IS, so that the sliding element 27 slides along the internal ribs 16, Vi. The UV lamp is switched on and the lamp casing 4 moves above the keyboard 2. UV light is emitted by the IJV lamp and directed to the surface of the keyboard 2 by the reflector(s) so that the surface of the keyboard 2 is sterilised, A typical sweep programme consists of two sweeps across the surface of the keyboard 2.

This can be from left to right, then right to left or right to left, then left to right. A preferred sweep time is one minute per one sweep across a keyboard 2. For heavy use/contamination, the sweep programme can be repeated or the sweep time extended.

The control unit 7 can be programmed to start a sweep program automatically after a period of non-use. The control unit 7 can be programmed to stop the sweep as soon as an obj ect is detected on the keyboard 2 (e.g. the user's hand) and/or if the keyboard is dislodged from its correct position. In the case where a sweep is interrupted, the casing 4 is automatically sent back to its rest position. The rest position can be programmed to be on the left of the keyboard (e.g. for right handed users) or on the right of the keyboard (e.g. for left handed users). The control unit 7 may be programmed to suit the user's preferences.

If the user wishes to sterilise another article, for example the computer mouse, the article is placed adjacent the keyboard 2 and the lamp casing 4 positioned at the end of the distal end of the housing 3A above the article and sterilisation can be initiated by the user.

The sterilisation process can be stopped automatically after completion or manually (e.g. by the user entering a command on a control pad or pressing a switch).

To store the device 1, the keyboard 2 is removed and the lamp casing 4 is pivoted about its neck 12 so as to sit along the upper surface of the housing 3A in its storage position. An example of pivoting mechanism is illustrated by figures 14A and 14B in which a cam 28 enables the rotation of the casing 4 about a vertical axis from an in-use position (substantially perpendicular to the housing 3A -see figure MA) to a storage position (substantially parallel to and along the upper surface of the housing 3A -see figure 14B). The device I can then be stored in this compact configuration.

In other preferred embodiment, the device I is used to sterilise a vertical surface, such as a computer screen 2 as shown in figure 15. The housing 3A is safely secured on top of the computer screen and, if present, the support 3B is positioned behind the computer screen. The lamp casing 4 at rest is positioned on the left or right hand side of the screen. In use, the lamp casing 4 emits germicidal light and sweeps across the surface of the screen.

Figures 16 to 23 are provided to describe additional or alternative features for a sterilising device according to the present invention, The features shown in the figures and described herein can be combined or used independently from each other to produce a device meeting the requirements of the user.

Referring to figure 16, there is illustrated a device 100 for sterilising an article 200, the device 100 comprising means for emitting a germicidal light and means for sweeping the emitted light over the article. The device 100 comprises a base 300 and a casing 400 for containing the means for emitting a germicidal light. The base 300 comprises an elongated hollow housing 300A, which is placed along a side of the article 200 and a support 300B extending along the longitudinal direction of the housing 300A to support at least part of the lower surface of the article 200.

Figures tO to 23 illustrate the following features of the present invention, which can be used independently from each other as required by the user, The device t, 100 comprises a visual indicator 301, for example and LED visual indicator.

The indicator may be in the shape of a light bar, In a preferred embodiment, the visual indicator 301 comprises a tn-colour LED to communicate the following to the user: colour (a) scan needed, colour (b) battery needs charging, colour (c) Fault refer to owner's manual. The visual signal can also be pulsed to convey a different message to customer. The visual indicator 301 can be positioned so as to be easily seen by the user, The visual indicator 301 is preferable positioned on the housing 300A.

The device 1, 100 may comprise one or more apertures 302 to emit a sound signal in S addition to or instead of the visual indicator 301.

The device support 30DB may comprise or consist of a silicone material. In a preferred embodiment, the support 300B comprises a silicone mat used to support a keyboard 200 and grip it to stop excessive movement, This feature may be used in addition to or instead of the tabs 5, 6 described above, Preferably, the support 30DB is flexible so that it can act as a protective cover around the housing 300A. The support 30DB can be rolled around the housing 200A so that the device can be more easily transported from site to site when used as a portable device.

The device 1,100 may comprise an opening 303 through or under the housing 300A for accommodating any cable or wire for connection to the article 2,200 (e.g. a keyboard USB wire).

Reference is made to figures 22A to 22C. This allows better cable management but also can assist as a positioning means, i.e. to position the article 2,200 relative to the device 1,100. In a preferred embodiment, an opening 303 is placed in the silicone matt allows the user to thread keyboard IJSB connector through the aperture 303 and clip the cable to the underside of the device 1, 100 and out the back of the device 1,100 ensuring that the keyboard is located securely and the cable managed correctly.

The device 1,100 may comprise a scan command/button 304, preferably with a corresponding visual indicator (not shown), such as a LED lighting ring. The button can be pressed by the user to run a scan, The (LED) visual indicator can be used to communicate the status of the scanning process and its function may be linked to the main visual indicator 301. A time delay can be built into this feature, for example, the user should hold the button for a time period, e.g. 3 seconds, prior to the lamp casing 400 moving in order to avoid accidently starting a scan.

The device 1, 100 may comprise means 305 for connecting the device to a power supply (e.g. the mains). This feature is preferably positioned at the rear of the device (in use) in order to improve cable management.

The device 1,100 comprises a slit 8, 800 to enable the lamp casing 400 to moves from one end of the device to the other. Preferably, the slit 8,800 is positioned towards the rear of the housing 300A to minimise the risk of dirt ingress in the top of the device.

The lamp casing 400 preferably comprises one or more apertures 401, such as air vents, preferably positioned on one or more sides of the lamp casing 400.

Figures 19 and 20 show inner components of the device 100. A motor 3 tO, preferably a step motor is coupled to gear wheels 311 A and 311 B, each positioned at each end of the housing 300A, by a belt 312. The belt 312 itself is coupled to the lamp casing 400, for example to a carrier portion 410. Thus, the lamp casing 400 can move back and forth in a controlled manner.

This belt system is also advantageous in that it does not require much space so that overall the device 1,100 can be a compact size and more space is available to include a battery, if required.

The carder portion 410 of the lamp casing 400 is slidably coupled to guiding means 314, for example rails 314, having a bearing surface which allows the carrier portion to move freely up and down the rails, The bearing surface is advantageous in that it provides a low cost, low friction solution and, with no moving parts, it is less likely to become damages and easier to maintain.

The device 1,100 comprises at least one printed circuit board (PCB) 315. This is the main control for the device and may comprise a lamp ballast. A flexible cable (not shown) may be connected to PCB 315, pass through the carrier portion 410 and be connected to a lamp PCB 412, There is space within the device, in particular in support 300A, to allow the flexible cable to move back and forth with the lamp casing 400.

A lamp motor 411, preferably a step motor 411, may be included in the lamp casing 400.

This motor may be a high torque geared step motor used to rotate the lamp casing 400. It may be coupled to the lamp PCB 412 along with the liv lamps 413, Wiring the lamps 413 and motor 411 to its own dedicated PCB eliminates the number of wires passing from moving head to main PCB 315 and makes the system easier to assemble and replace parts, if required.

The device 1,100 may comprise a rechargeable battery 313. This is particularly advantageous in a portable version of the device. The rechargeable battery 313 may be accessible via a battery door (not shown) so that the user can easily replace when required.

All items above may be mounted to a base moulding and a top cover will be added last and screwed in place. This makes the product easy to assemble and set up during manufacture.

The device according to the present invention may be configured to be permanently situated on a desktop or may be configured as portable version for mobile use.

Figures 25 and 26 show preferred electronic systems for use in a device 1, 100 according to the present invention. The electronic system is preferably enclosed in the support 3A, 300A of the device.

In the embodiment illustrated in figure 25, the device 1,100 comprises two circuit boards or printed circuit boards (PCB). A primary control board comprises the circuitry for controlling the device. The secondary PCB comprises other features, for example, it may contain the power inlet, battery charger and/or power regulation system or may more simply provide wired connections to some off-board components such as indicator LEDs or switches.

In the embodiment illustrated in figure 26, the device 1,100 comprises three circuit boards or printed circuit boards (PCB). The UV lamp or tubes and the motor can be plugged into an interconnecting PCB to reduce the number of wires between the movable lamp casing 400 and main control PCB 315 and lighting ballast.

Power Supply: The electronic system may comprise a DC powerjack for connection to an off the shelf mains to DC power unit. The power unit may be specified and suitably rated to power all features of the device, Preferably, the system can be powered from 12V DC.

Power switch: The device 100 may comprise a main power switch which can be conveniently positioned to be accessible by the user. The device will not operate and will consume a minimal amount of power from the battery when switched off.

Battery: The device 100 may comprise a rechargeable battery 313, for example an integrated Lithium Ion (or similar) rechargeable battery. The battery 3 3 preferably provides 4 hours of operation or more. The circuit board set may incorporate circuitry to charge the battery 313 whenever the device is powered via the external DC power supply.

Battery operation: The device 100 may run from the DC power supply when connected and powered -even if the device is switched off via the built-in power switch. The device 100 may operate from the internal battery without the need for the DC power supply. The device 100 may indicate battery status via a LED which may be visible to the user, Operation between the external power source and the battery may be automatized. The device may continue to ifinction from the internal battery when the external power source is disconnected or switched off Power saving mode: When powered from the internal battery, the device may be configured to consume a minimal amount of power from the battery between scans.

User Interface: The device may incorporate a clean, minimal user interface which may comprise one or more of: Visual indicators: Indicator LEDs may provide visual feedback of the current condition of the unit, For example: * Next Scan due: A fixed period time lapse from the last scan will illuminate / flash an LED on or around the start! scan button. The micro will go to sleep to conserve battery power (if it is not plugged in) until it is time to flash the LED again.

* Battery state indicator (orange): o constant on when battery capacity is SO to 100% o 50% duty cycle (1 second period) when battery capacity is 25 to 50% o 25% duty cycle (0,5 second period) fast flash when capacity is below 25% * Battery charging indicator (green) o LED pulsing characteristics * Device status indicator (red/green) o Red flashing under fault condition (see fault indication) o Green constant when device is operating

S

Fault indicator: The device fault indicator may provide feedback for the user when a fault condition occurs, Fault conditions may include: * Scan fault (not reached target position within allowed time) * Park fault (not reached target position within allowed time) Sound indicator: The device may incorporate a piezo-sounder which may emit audible signals while/ before/ when finished operating. These signals may include: * Momentary beep when the device starts a scan IS * Momentary beep when the device finishes a scan * Repeating sound (e.g. 10 seconds duration) when a fault is detected * The repeating sound may end when the user presses the start button Start button: The device may include an accessible start button. The scan process may commence when the start button is pressed. When the start button is pressed during a scan it will pause the scan and when pressed again will resume scan.

The electronic system may comprise means for wireless communication (e.g. Wi-Fi or Bluetooth).

Control System: The system may include one or more of: * Microcontroller (e.g. ARIVI Cortex MO) to provide automation and user interaction * Two DC motors o Park o Scan * Motor drivers (to power and control the park and scan motors) * Limit switches o Park: Park position reached o Park: Scan position reached o Scan: Start position reached o Scan: End position reached Motors: The motors may be selected to suit the application. The device may comprise mean for monitoring the motor current for positional limit detection. The circuit board(s) may be configured to enable the microcontroller to monitor up to four limit switches for detecting both ends of stoke of the park and scan mechanisms.

Process sequence: The embedded firmware may enable the following automated sequence: * Await start' button press * Emit process started sound * Enable process running' indicator * Rotate head from park to scan position o Switch park motor on (head direction CCW) o Await limit switch at head in scan position' * Fault if not reached in allotted time o Switch park motor off * Switch UV lamps on * Traverse head across keyboard o Switch scan motor on (head direction left to right) o Await limit switch at scan reached right end' * Fault if not reached in allotted time * Return head o Change scan motor direclion fright in leVi) o Await limit switch at scan reached left end' * Fault if not reached in allotted time o Switch scan motor off * Switch UV lamps off * Return head to park position o Switch park motor on (head direction CW) o Await limit switch at head in park position' Fault if not reached in allotted time o Switch park motor off Emit completed' sound * Disable process running' indicator The device according to the present invention reliably and automatically administer UV light to keyboards, mice and other portable electronic equipment to ensure they are free from germs. The device can be used as a fixed item permanently installed on a desk and as a portable product that can be taken to site and used in multiple ocations. The device improves the cleanliness of our IT equipment to prevent the spread of infection within public spaces! buildings.

EXPERIMENTAL DATA

Tests have been carried out to demonstrate the efficacy of the invention against four organisms found to be representative of environmental contaminants of concern within the food manufacturing and catering industry.

L Method * BS EN 13697:20W: Chemical disinfectants and Antiseptics, Quantitative non-porous surface test for the evaluation of bactericidal and/or fungicidal activity of chemical disinfectants used in food, industrial, domestic and institutional areas * The four organisms are Staphylococcus aureus (NCIMB 9518), JJsteria monocytogenes (NCTC 10357), Salmonella Tjphimurium (FH 68) and Escherichia coil (NCIIVIB 8879).

2. Experimental set-up 2.1 Preparation of metal discs Stainless steel discs (2cm diameter, Grade 2 B 1.4301 [EN 10088-1, EN 10088-2]), previously sterilised in accordance with MA-FI-I-017 (ES EN 13697:2001).

2.2 Inoculum preparation Working subcultures of each of the challenge bacteria were derived from the master stock culture. All subcultures were incubated for 24 hours at 37 C. A first subculture from the master culture was used as the working culture and was recovered by adding 5g of sterile glass beads and 9mL Maximum Recovery Diluent (MRD) to each slope. The slopes were then shaken gently to remove the culture from the agar surface, The resultant suspension was then filtered through a funnel containing sterile glass wool and eluted with further MRD to maximise recovery.

The optical density of each material suspension was measured at 420nm and calibration graphs of absorbmce against viable count were used to determine the concentration. The suspension was then diluted with MRD to give an approximate concentration of to8cfu.mL', 2.3 Inoculation of metal discs Cleaned stainless steel discs (2,1) were split into 4 sets of 9 discs (one set per challenge organism). Each set of discs was inoculated with 0.OSmL of an approximate lO8cfu.mL1 inoculum suspension of the relevant organism, The suspensions were dried onto the discs at a temperature of 37 C for approximately 1 hour and then allowed to equilibrate to room temperature.

Three inoculated discs for each organism were untreated and used as the controls, p.., Li 2.4 First experimental set-up -Sweep Three inoculated discs for each organism were placed upon a 6 x 6 inch grid and the UV light source (at approximately 254 mm) was moved across the surface (right to left and left to S right) at a height of 0.5 inch for 45 seconds. A single 4 Watts UV lamp was used.

2.5 Second experimental set-up -Stationary Three inoculated discs for each organism were placed in a line and the UV light source (at approximately 254 nm) was placed directly over the discs at a height of 0.5 inch for 45 seconds.

A single 4 Watt UV lamp was used.

2.6 Processing of discs After treatment, the treated and untreated discs were aseptically transferred into sterile plastic universal containers (diameter 4-Scm) containing Sg sterile glass beads (diameter 3-4mm) and lOmL Maximum Recovery Diluent (MRD), The containers were agitated on a horizontal surface for minute to recover the surviving bacteria into suspension.

Each sample was serially diluted in TvIRD to i04 and plated out in pour plates using Tryptone Soya Agar. The plates were incubated aerobically at 37 C for at least 48 hours.

3. Results Table 1 below is a summary of the raw data. The results are expressed as mean log difference and percentage difference compared to the controls.

Log reduction was determined using the following formula: MLR=LOGCD-LOGED wherein: MILR Mean log reduction LOG CD Mean log recovered organisms from the control discs LOG ED Mean log recovered from discs exposed to UV light The percentage reduction was determined using the following formula: %R(CFUCD-CFUEDx 100

CFU CD

wherein: %R Percentage reduction CFTJ CD Recovered organisms from the control discs CFTJ ED Recovered organisms from the discs exposed to UV light

Tablet

Log difference from control % difference from control TJV source IJV source TJV source UV source stationary sweeping stationary sweeping E. coil 0,86* 0,86* 86,24* 86,24* L. Inoflocy/ogefleS 2,28 1.50 99,48 86,84 aureus 1.59 1.02 97.40 90.43 1S1 Jyphirnunun; 2.09 0.94 99.19 88.47 * No E. coil was recovered from the test surfaces and drying reduced the number of recoverable cells on the control and thus these were the maximum log and % reductions achievable within the test.

The results show optimum efficiency with both sweeping and stationary UV light sources with respect to E.co/i and optimum to satisfactory efficiency with respect to L. monocytogenes, S aurens and S. Typhirnuriwn.

An increased height above the test surface whilst allowing a greater area to be illuminated reduces the efficacy of the germicidal light due to increased air depth to be penetrated and interfering surrounding light before coming into contact with the challenge organism.

Height may also affect the exposure time in particular when using the sweeping germicidal light source. The closer the test surface, the smaller the illuminated area and the exposure time is a function of area illuminated, the area being swept and the speed of sweeping. It should also be noted that high concentrations of vegetative bacteria (viable or not) can in themselves act as an organic interfering substance and protect cells located below them from the germicidal light.

The inventor has found that a distance of 0.5 inch (15mm) between the UV lamp and the surface to be sterilised results in optimum sterilisation efficiency and homogeneity. The inventor also found that a sweep time of 60 seconds results in optimum sterilisation for a standard Iceyboard (40-45cm). The light may sweep at a speed of from 400mm/minute to 500mm/minute.

For example, a typical sweep time over the surface of a standard computer keyboard is 45 -60 seconds, preferably 60 seconds, The UV lamp will make 2 passes over the keyboard resulting in a scan time of circa 120 seconds or 2 minutes. Moreover, further experimentations have shown that 3 lamps of 4 Wafts each provide optimum results, superior to those achieved with a single 4 Watt lamp, whilst offering a good practical compromise.

Thus, from the above description, it can be seen that the present invention efficiently sterilises, sanitises and/or disinfects articles, whilst minimising disruption for the user. The sterilisation process takes place when the article is not in use and the sterilisation process does not require extended UV exposure time, It does not require the removal and isolation of the article into a separate chamber. The sterilisation device according to the present invention can be stored in a compact configuration or simply left on the desktop or work surface when not in use.

It is smaller than existing sterilisation devices and therefore suitable for us in facilities where no or limited storage space or desk space is available. The process does not require expensive and bullcy equipment and can be applied to any standard every day articles, Finally, the device according to the present invention can be used safely as it is itself not prone to contamination and includes a number of safety features for example to correctly install the article, to prevent damage due to user's movements or obstacles, to minimise leakage of UV light.

Claims (21)

1. CLAIMSI. A device for sterilising an article, the device comprising means for emitting a germicidal light and means for sweeping the emitted light over the article.
2. 2. The device according to claim I wherein the device further comprises a base and a casing for containing the means for emitting a germicidal light, wherein the casing is slidably connected to the base.
3. 3. The device according to claim 2, wherein the base is an elongate base and the casing is slidable in the longitudinal direction of the base.
4. 4. The device according to claim 2 or 3, wherein the casing is pivotable relative to the base from a use position substantially perpendicular to the base to a storage position substantially parallel to the base.
5. 5. The device according to any one of claims 2 to 4, wherein the casing is pivotable in the radial direction of the base.
6. 6. The device according to any one of claims 2 to 5, wherein the casing comprises means for reflecting germicidal light towards the article,
7. 7. The device according to any preceding claim, wherein, in use, the distance between the surface of the article to the means for emitting a germicidal light is from 0.75 inch to 0.5 inch (19.05mm to 12.7 mm), preferably 0.5 inch (t2.7 mm).
8. 8. The device according to any preceding claim, wherein the device further comprises means for detecting the article.
9. 9. The device according to any preceding claim, wherein the device further comprises means for detecting the presence of an object on the article.
10. 10. The device according to any preceding claim, wherein the device ifirther comprises a control unit.
11. II. The device according to any preceding claim wherein the device comprises a plastic material.
12. 12. The device according to any preceding claim, wherein the device comprises one or more antibacterial agent.
13. 13. The device according to any preceding claim, wherein the device comprises a heat resistant material and/or a UV resistant material.
14. 14. The device according to any preceding claim, wherein the germicidal light is UV light.
15. 15. The device according to claim 2, wherein the TJV light is in the range of 200 nm to 280 nm, preferably 260nm.
16. 16. The device according to any one of claims 1 to 13, wherein the germicidal light is plasma-based or plasma-generated.
17. 17. The device according to any preceding claim, wherein the light emitting means is a lamp.
18. 18. A device substantially as described herein with reference to the accompanying figures and examples.
19. 19. A method for sterilising an article comprising the steps of directing germicidal light onto the article using a device according to any one of claim I to 18 and sweeping the emitted light over the surface of the article,
20. 20. The method according to claim 18, wherein the light is swept at a speed of from 400mm/minute to 500mm/minute.
21. 21. A method substantially as described herein with reference to the accompanying figures and examples.