GB2454642A

GB2454642A - Portable UV steriliser

Info

Publication number: GB2454642A
Application number: GB0713256A
Authority: GB
Inventors: Philip Mutton; Alex Wolski; Stephen Colin Brown
Original assignee: Dezac Group Ltd
Current assignee: Dezac Group Ltd
Priority date: 2007-07-09
Filing date: 2007-07-09
Publication date: 2009-05-20
Also published as: GB0713256D0

Abstract

A portable ultraviolet germicidal irradiation device including a body housing a UV-C radiation source for generating UV-C radiation of a wavelength and intensity sufficient to render harmless microorganisms exposed to said UV-C radiation; and at least one switch or sensor for detecting or otherwise recognising an undesirable occurrence by altering the condition of the switch or sensor; wherein the switch or sensor causes operation of the device to be interrupted when the undesirable occurrence is detected or otherwise recognised. The invention sets out to provide safety features such as a dead man's switch, a lock, a timer and a bright light to deter users from pointing the device towards their eyes.

Description

I

STERILISING APPARATUS

The present invention relates generally to a sterilising device and in particular, but not exclusively, to Ultraviolet Germicidal Irradiation (UVGI) devices intended for home usage.

In the past, home sterilisation has been traditionally achieved through use of chemical disinfectant and sanitisers. The use of chemicals for sterilisation however presents certain problems. Very few disinfectants and sanitisers can sterilise (e.g. completely eliminate all microorganisms) and almost all are toxic to humans. Use of chemical disinfectants must be done with care as potentially harmful by-products can be produced, or damage can occur to the surfaces .. : being cleaned, due to the highly reactive nature of the chemicals used. S...

Furthermore, continual use of chemical disinfectants has resulted in some *..S viruses and bacterial endospores acquiring tolerance.

The use of electromagnetic energy for sterilisation is well known, in

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***..I * particular Ultraviolet Germicidal Irradiation (UVGI), which is a sterilisation method that uses UV-C ultraviolet light. UV-C light is electromagnetic radiation of wavelength less than 280nm, and which possesses germicidal properties. A particularly important UV wavelength is 254nm: UV light of this wavelength is known to be harmful to microorganisms by causing adjacent thymine molecules within the microorganisms' DA to dimerise. This inhibits the microorgranisms' ability to replicate and thereby renders microorganisms harmless.

In humans, prolonged exposure to UV-C radiation may result in acute and chronic health effects relating to the skin, eye, and immune system. Furthermore UV-C can produce ozone, which can have a harmful effect on the respiratory system.

Because of the safety considerations inherent with the use of these devices, traditionally UVGI has been carried out within specialist biological laboratories and medical facilities rather than at home.

There is therefore a need for an UVGI device that it can be used safely by the domestic market.

Accordingly, in a first, broad aspect, this invention concerns a portable ultraviolet germicidal irradiation device including: a body housing a UV-C radiation source for generating UV-C radiation of a wavelength and intensity sufficient to render harmless microorganisms exposed to said UV-C radiation, *..* : with one or more safety features designed to prevent accidental misuse of the * * S...

device.

In a first particular aspect of this invention, there is provided a portable S..

ultraviolet germicidal irradiation device including: a body housing a UV-C *..

* S radiation source for generating UV-C radiation of a wavelength and intensity sufficient to render harmless microorganisms exposed to said UV-C radiation; at least one switch or sensor for detecting or otherwise recognising an undesirable occurrence by altering the condition of the switch or sensor; wherein the switch or sensor causes operation of the device to be interrupted when the undesirable occurrence is detected or otherwise recognised.

In a preferred embodiment, the device includes a dead man's switch which requires a user of the device to satisfy a condition in order that the switch attains an on state in which the device can be operated, and wherein the switch adopts an off state if the user does not satisfy the condition which causes operation of the device to be interrupted. Preferably, the condition is the application of pressure to the switch by the user. Dead man's switches are also commonly known as momentary switches, dead man's handles or killer switches. Other switches or sensors could be used to perform a similar function.

The device may include an angular position switch which causes operation of the device to be interrupted when the switch detects that the device is inclined at a predetermined angle from a reference axis. Preferably, the angular position switch is a tilt switch which detects whether the device is inclined at a predetermined angle from a horizontal axis. This feature prevents or reduces the risk of accidental exposure of the user to the UV-C radiation, which .. : could be injurious to the skin or eyes should the device be inadvertently S... * * *...

orientated away from a surface which has been sterilised. It is possible in some ***.

embodiments to utilise a tip-over switch which detects whether the device is *..

inclined at predetermined angle from a vertical axis. **...

* The device may include control means responsive to the condition of the switch or sensor for interrupting operation of the device when the undesirable occurrence is detected or otherwise recognised. In the case of switches, a control means may or may not be necessary, since it may be possible to incorporate the switch directly into an electrical circuit which powers the UV-C radiation source.

The device may include a sensor for detecting the proximity of the device to a surface, and control means responsive to the output of said sensor for inhibiting operation of the device when the device is greater than a

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predetermined distance from the surface. The sensor may include a source of electromagnetic radiation and a detector for detecting the electromagnetic radiation returning from the surface. The sensor may conveniently comprise a combination of a photocell and LED or laser, and an electrical circuit for determining the proximity of the device to the surface. The electrical circuit may for example determine from the photocell the measured intensity of the reflected beam from the LED or laser and compare this to a predetermined acceptable intensity.

Other sensors could be used with similar function for determining the proximity of the device to the surface. For example, the sensor incorporating a sonic beam may determine the distance of the device from the surface, and the . : output of this sensor may be used by the control means to inhibit operation of S...

the device.

In a second aspect of the invention there is provided a portable ultraviolet germicidal irradiation device including: a body housing a UV- C radiation source S. .**S * for generating UV-C radiation of a wavelength and intensity sufficient to render harmless microorganisms exposed to said UV-C radiation; and control means for operating the device, said control means including a lock for preventing unauthorised use.

Said lock may take various forms; for example, it could include a keypad for a user to input an identification code, with operation being inhibited unless the correct code is input; it could include a key operated switch such that only a user with the key can turn the device on; and/or the correct activation of a series of user inputs activated in the correct order. The control means may inhibit operation of the UV-C radiation source unless a series of two or more actions are performed. For example the control means may inhibit operation of the UV-C radiation source until an activation key is inserted and a user has pressed a control switch. One of the actions may be the placing of the device on a surface.

This condition might be detected using one or more sensors in accordance with the first aspect of the invention. The control means may require that these actions be performed in the correct order.

In a third aspect of this invention, there is provide a portable ultraviolet germicidal irradiation device including: a body housing a UV- C radiation source for generating UV-C radiation of a wavelength and intensity sufficient to render harmless microorganisms exposed to said UV-C radiation; an indicator; and a...

means for operating the indicator in order to communicate the status of the S... * S ***.

device to a user.

The indicator may take various forms; for example, it could include a S..

visible display light which turns on or changes colour when the device is in S.....

* operation, or an audible noise which sounds when the device is in operation or a combination of the two. Furthermore, the control means and indicator may display various modes of operation of the device. For example the indicator means may change colour to indicate that the device is in a standby mode of operation following the insertion of an activation key or that the battery of the device is low on power and requires recharging or replacement.

In a fourth aspect of the invention, there is provided a portable ultraviolet germicidal irradiation device including: a body housing a UV-C radiation source for generating UV-C radiation at a wavelength and intensity sufficient to render

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harmless microorganisms exposed to said UV-C radiation; and a further light emitting element arranged to emit a beam of radiation non-injurious to the eye in generally the same direction as the UV-C radiation generated by the UV-C radiation source, in which the beam of non-injurious radiation is of an intensity sufficient to deter a user from aiming the device towards their eye.

The high intensity beam is non-injurious in the sense that whilst it may be unpleasant to look into the beam, no permanent injury is caused by that beam.

Preferably the beam of non-injurious radiation is turned on as soon as the device is powered and before the light source is activated. The further light emitting element preferably emits light at a wavelength to which the eye is particularly sensitive such as light of wavelength of the order of 500-600nm and : ideally around 555nm. The light emitting element may comprise an LED I...

designed to provide light of the required wavelength.

In a fifth aspect of this invention, there is provided a portable ultraviolet S..

germicidal irradiation device including: a body housing a UV-C radiation source *****S * for generating UV-C radiation of a wavelength and intensity sufficient to render harmless microorganisms exposed to said UV-C radiation; and control means including a timer for interrupting operation of the device after a preset period.

This feature prevents over exposure of the skin from reflected rays, which could result in skin damage, and also forces the user to remove the UV-C radiation source from the targeted area between uses.

In a sixth aspect of this invention, there is provided a portable ultraviolet germicidal irradiation device including: a body housing a UV-C radiation source for generating UV-C radiation of a wavelength and intensity sufficient to render harmless microorganisms exposed to said UV-C radiation; in which the UV-C radiation source is a non-ozone generating UV-C radiation source.

Preferably said non-ozone generating UV-C radiation source is a high voltage discharge tube; however the non-ozone generating UV-C radiation source could be a solid state device such as a LED.

In general, the non-ozone generating UV-C radiation source is one which does not produce appreciable UV output at wavelengths below around 190-200nm. In general, the non-ozone generating UV-C radiation source is one which does not cause photolysis of oxygen.

In a seventh aspect of the invention, there is provided a portable ultraviolet germicidal irradiation device including: a body housing a UV-C : radiation source for generating UV-C radiation of a wavelength and intensity S...

sufficient to render harmless microorganisms exposed to said UV-C radiation; S...

*.. and a portable power source providing an electrical output for powering the UV-*5* C radiation source.

*5*SS* * Preferably, the portable power source is a battery. Advantageously, the portable power source is a rechargeable battery, and the portable device further includes recharging means for enabling the rechargeable battery to be recharged. Alternative power sources, such as a fuel cell, might be envisaged.

The portable device may include more than one portable power source.

Thus, the portable device may include an ancillary portable power source for powering ancillary functions of the portable device.

Whilst it is preferable that the device is powered from a portable source in accordance with the seventh aspect of the invention, it should be appreciated that other aspects of the invention might be implemented using a device powered from a mains power supply.

In all aspects of the invention, it is preferred that the UV-C radiation source generates UV-C radiation of a wavelength greater than 200nm for rendering harmless microorganisms. Most preferably, the UV-C radiation source generates UV-C radiation of about 254nm. UV-C radiation of this wavelength disrupts microorganisms' ability to replicate. The term "about 254nm" is understood to include reference to wavelengths between 253 and 255nm.

The invention may be embodied in an applicator type device, which contains at least the majority of the components and control functionality, required for the operation of the device. Alternatively, the device may be in the S...

form of a separate base unit, which contains the majority of the control S...

S.. functionality, with a separate head unit containing the UV-C radiation source. *SS*

The head unit may be connected to the base unit by a flexible link.

T5 Whilst the invention has been described above, it extends to any

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* inventive combination of the features set out above, or in the following

description, drawing or claims.

The invention may be performed in various ways, an embodiments thereof will now be described by way of example only, reference being made to the accompanying drawings, in which: -Figure 1 is a perspective view of a first embodiment of a device of the invention showing the upper face thereof; Figure 2 is a perspective view of the first embodiment of a device of the invention showing the lower face thereof; Figure 3 is a perspective view showing the internal arrangements of the first embodiment of a device of the invention; and Figure 4 is a perspective view of a second embodiment of a device of the invention showing the lower face thereof.

Figure 1 depicts a portable device of the invention, shown generally at 1, comprises a housing 2, which contains a non-ozone producing UV-C radiation source (not shown) suitable for effecting the sterilisation of microorganisms and arranged to project a beam through an elongate opening 5 which extends along a longitudinal axis of the device. Non-ozone producing UV-C radiation sources can be obtained from, for example, Topbulb.com of East Chicago, USA.

Figure 2 depicts the reverse lower side of the device 1 which further *** : comprises a press and hold "dead man's switch" control button 4 for controlling S...

the function of device 1, LED indicator 6 for displaying the operational mode of a.'.

device 1 and a key operated switch 13. A compartment 7 houses a portable and rechargeable battery (not shown).

*5*SSs * The internal arrangement of the portable device 1, is shown in more detail in Figure 3, which depicts the device with the lower portion of the housing removed. The remaining housing 2 contains the UV-C radiation source 3. The battery is used to power the device 1, including the UV-C radiation source 3.

The battery also powers the ancillary functions of the device 1, principally supplying appropriate power to controller 8. The controller 8 controls the operation of the UV-C radiation source 3. The battery is rechargeable and as shown in Figure 2 appropriate recharging means 9 are provided in the compartment 7 which enable connections to be made (for example via a suitable input socket 10) to a mains power supply for the purposes of recharging the battery.

In use, the control circuit inhibits operation of UV-C radiation source 3 until certain conditions are fulfilled. In this particular example, it is necessary firstly to turn on the unit using a key (not shown) which is inserted in key switch 13. Upon detection of the correct key, controller 8 changes the colour of LED indicator 6 to show that device I is in a stand-by mode of operation. When these steps have been carried out, the device 1 may be offered up to the area of the surface where sterilisation is required and the main UV-C radiation source 3 can be activated by pressing and holding the control button 4. Upon activation of the main UV-C radiation source 3, control unit 8 changes the colour of LED : indicator 6 to shown that the device is in use and potentially hazardous invisible *..s light is being emitted. *. .

It will therefore be appreciated that the embodiment illustrated in Figures 1 to 3 requires several security stages to be passed before the device 1 can be S*d..

* operated; the first level security checks the credentials of the user, for example by being in possession of the right key, and thereafter physical security is assessed by ensuring that the control button 4 is continually held while the UV-C radiation emitter is enabled. Control button 4 must be continually pressed for the device 1 to operate-relaxation of pressure against control button 4 causes an electrical current in the device 1 to be broken thereby inhibiting operation of the UV-C radiation source 3.

A second embodiment a device of the invention, shown generally at 40, is illustrated in Figure 4. Features common to the first and second embodiments have like numbering.

Adjacent the UV-C radiation source 3 is an LED 11 designed to project a high intensity beam of non-injurious visible light substantially in the same direction as the UV-C radiation emitted by the UV-C radiation source 3. At least a portion of the beam of non-injurious light propagates from the longitudinal axis of the device 40. Adjacent to LED 11 is a photocell 16 arranged so as to detect the reflected high intensity beam of non-injurious light.

In use the controller 8 inhibits operation of UV-C radiation source 3 until certain conditions are fulfilled. In this particular example, it is again necessary firstly to turn on the unit using a key 1 in key switch 3. Upon detection of the correct key control unit 8 changes the colour of LED indicator 6 to show that device 40 is in standby mode of operation. When these steps have been carried out, the control unit activates LED 11, so that a high intensity beam of visible light is projected along the longitudinal axis of the device 40, both as a warning of the projected axis of the UV-C radiation beam from the UV-C radiation source * . S 3 when it is activated and also to deter users from pointing it towards their own S...

or other's eyes. Having passed the initial security steps, the device 40 may be S...

offered up to the area of the surface where sterilisation is required and proximity to the surface is detected from a measurement of the intensity of reflected light *S S...

* 20 by the controller using the photocell 16.

In this second embodiment of the invention, the UV-C radiation source 3 can only be activated by pressing and holding the control button 4. Upon activation of the UV-C radiation source 3, the control unit 8 changes the colour of the LED indicator 6 to show that the device is in use and potentially hazardous invisible light is being emitted.

It will therefore be appreciated that the second embodiment illustrated in Figure 4 requires several security stages to be passed before the device 1 can be operated; the first level security again requires use of the correct key, and thereafter physical security is assessed by ensuring that both the control button 4 is continually held and the device is maintained within a safe proximity to the surface before the UV-C radiation emitter is enabled.

In some embodiments of the invention (including the first and second embodiments described herein) the control unit 8 includes a tilt switch 15 mounted so as to detect the orientation of the device. In use, the control circuit inhibits operation of the UV-C radiation source 3 where the vertical angle is larger than a predetermined value.

Modifications, alternatives, variants, additions and simplifications to the embodiments described above, and illustrated will be readily apparent to the skilled addressee. In particular, not all the safety features mentioned above S... * S S

need to be used together, or the features mentioned could be combined. *.* S... S... *S.

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Claims

1. A portable ultraviolet germicidal irradiation device including a body housing a UV-C radiation source for generating UV-C radiation of a wavelength and intensity sufficient to render harmless microorganisms exposed to said UV-C radiation; and at least one switch or sensor for detecting or otherwise recognising an undesirable occurrence by altering the condition of the switch or sensor; wherein the switch or sensor causes operation of the device to be interrupted when the undesirable occurrence is detected or otherwise recognised.

2. A portable ultraviolet germicidal irradiation device according to Claim 1 including a dead man's switch which requires a user of a device to satisfy a condition in order that the switch attains an on state' in which the device can be operated, and wherein the switch adopts an off state' if the user does not satisfy the condition which causes operation of the device to * S * be interrupted. *..

3. A portable ultraviolet germicidal irradiation device according to *.*.

Claim 2 in which the condition is the application of pressure to the switch by the user.

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* 20

4. A portable ultraviolet germicidal irradiation device according to any one of Claims 1 to 3 including an angular position switch which causes operation of the device to be interrupted when the switch detects that the device is inclined at a predetermined angle from a reference axis.

5. A portable ultraviolet germicidal irradiation device according to Claim 4 while the angular position switch is a tilt switch, which detects whether the device is inclined at a predetermined angle from a horizontal axis.

6. A portable ultraviolet germicidal irradiation device according to any previous Claim including control means responsive to the condition of the switch or sensor for interrupting operation of the device when the undesirable occurrence is detected or otherwise recognised.

7. A portable ultraviolet germicidal irradiation device according to Claim 6 including a sensor for detecting the proximity of the device to a surface, and control means responsive to the output of said sensor for inhibiting operation of the device when the device is greater than a predetermined distance from the surface.

8. A portable ultraviolet germicidal irradiation device according to Claim 7 in which the sensor includes a source of electromagnetic radiation *:: and a detector for detecting the electromagnetic radiation returning from the a.. surface.

9. A portable ultraviolet germicidal irradiation device including a S...

body housing a UV-C radiation source for generating UV-C radiation of a wavelength and intensity sufficient to render harmless microorganisms S....

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exposed to said UV-C radiation; and control means for operating the device, said control means including a lock for preventing unauthorised use.

10. A portable ultraviolet germicidal irradiation device according to Claim 9 wherein said lock comprises one or more of: a keypad for the user to input an identification code, with operation being inhibited unless the correct code is input; a key operated switch such that only a user with the key can turn the device on; and/or the correct activation of a series of user inputs activated in the correct order.

11. A portable ultraviolet germicidal irradiation device according to Claim 10 wherein said lock comprises control means which inhibits operation of the laser unless a series of two or more actions are performed.

12. A portable ultraviolet germicidal irradiation device according to Claim 11 wherein the control means requires that these actions are performed in the correct order.

13. A portable ultraviolet germicidal irradiation device including: a body housing a UV-C radiation source for generating UV-C radiation of a wavelength and intensity sufficient to render harmless microorganisms exposed to said UV-C radiation; an indicator: and control means for operating the indicator in order to communicate the status of the device to a user. * * *

14. A portable ultraviolet germicidal irradiation device including: a **** body housing a UV-C radiation source for generating UV- C radiation of a S...

wavelength and intensity sufficient to render harmless microorganisms exposed to said UV-C radiation and a further light emitting element arranged *.***. S *

to emit a beam of radiation non-injurious to the eye in generally the same direction as the UV-C radiation generated by the UV-C radiation source, in which the beam of non-injurious radiation is of an intensity sufficient to deter a user from aiming the device towards their eye.

15. A portable ultraviolet germicidal irradiation device according to Claim 14 in which the beam of non-injurious radiation is turned on as soon as the device is powered or before the UV-C radiation source is activated.

16. A portable ultraviolet germicidal irradiation device including: a body housing a UV-C radiation source for generating UV-C radiation of a wavelength and intensity sufficient to render harmless microorganisms exposed to said UV-C radiation; and control means including a timer for interrupting operation of the device after a preset period.

17. A portable ultraviolet germicidal irradiation device including: a body housing a UV-C radiation source for generating UV-C radiation of a wavelength and intensity sufficient to render harmless microorganisms exposed to said UV-C radiation; in which the UV-C radiation source is a non-ozone generating radiation source.

18. A portable ultraviolet germicidal irradiation device including: a body housing a UV-C radiation source for generating UV-C of wavelength and intensity sufficient to render harmless micro organisms exposed to said * * S UV-C radiation; and a portable power source providing an electrical output S...

for powering the UV-C radiation source. S...

S *5S*

*

19. A portable ultraviolet germicidal irradiation device according to Claim 18 in which the portable power source is a battery.

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20. A portable ultraviolet germicidal irradiation device according to Claim 19 in which the portable power device is a rechargeable battery, and the portable device further includes recharging means for enabling the rechargeable battery to be recharged.

21. A portable ultraviolet germicidal irradiation device according to any previous Claim in which the UV-C radiation source produces UV-C radiation of wavelength greater than 200mm, preferably of a wavelength of about 254mm.

22. A portable ultraviolet germicidal irradiation device substantially as described herein with reference to the accompanying drawings. S... * S * S. * *.* * S 5.55 5...

S 5..

S S..

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