GB2421220A

GB2421220A - Computer input apparatus having UV light source

Info

Publication number: GB2421220A
Application number: GB0513584A
Authority: GB
Inventors: Pratik Sharma
Original assignee: Medisafe Technologies Europe Ltd
Current assignee: Medisafe Technologies Europe Ltd
Priority date: 2004-12-15
Filing date: 2005-07-01
Publication date: 2006-06-21
Anticipated expiration: 2025-07-01
Also published as: GB2421217A; GB2421220B; GB0427440D0; GB0513584D0

Abstract

A computer input apparatus (1;11) comprising a computer input device (2; 14, 26), ultraviolet light source means (3; 18), the computer input device (2; 14, 26) and the ultraviolet light source means (3; 18) being moveable relative to one another whereby an outer surface of the computer input device (2; 14, 26) can be irradiated with ultraviolet light to disinfect it, and control circuit means adapted to monitor use of the computer input device (2; 14, 26) by a user and, after a predetermined period of lack of use of the computer input device, to permit further use of the computer input device only after irradiation of the computer input device (2; 14, 26) with ultraviolet light for disinfection thereof.

Description

COMPUTER INPUT APPARATUS This invention relates to a computer input apparatus, such as a computer keyboard. More particularly it relates to a computer input apparatus, such as a computer keyboard, which incorporates a built-in disinfection feature using ultraviolet (UV) light. Such a computer input apparatus is particularly suitable for use with a personal computer (PC) in a hospital environment. The use of ultraviolet light as disinfecting agent helps to minimise the incubation and spread of infectious bacteria, such as methicillin-resistant Staphylococcus aureus (also known as MRSA), as well as viruses, in a hospital environment. Present research in the United Kingdom and recent figures supplied by the United Kingdom National Health Service (NHS) suggest that the rate of spread of infections has risen by 3.4% in the United Kingdom. Thus over 7000 patients per year pick up post operative infections. In an effort to control infections in hospitals, the United Kingdom National Health Service today spends an estimated 1 billion on measures designed to minimise such post-operative infections. It has also been found in various different research projects and trials that one most common frequent carrier and incubating ground for infectious viruses and bacteria (especially MRSA) is the computer keyboard, commonly a PC keyboard, used by doctors or other medical personnel in hospitals and intensive care units (ICU's). Pens used by doctors or other medical personnel are further carriers and incubating grounds for infectious viruses and bacteria. All of the above problems due to bacteria or viruses possibly present on a computer keyboard could be contained or minimized if the keyboard is cleaned using alcohol wipes after every use. It has been also proven that rate of spread of infectious viruses is controlled by this activity. However, this method is solely dependent on the user and the availability of the wipes. International Patent Publication No. WO 03/061382 Al discloses use of pulsed light, for example UV light from a xenon lamp in a pulsed system, to deactivate toxic and pathogenic bacteria on articles such as pieces of mail or keyboards. In United States Patent Application Publication No. 2003/0071790 Al there is taught a mouse seat with sterilising and deodorising ability wherein an ultraviolet lamp pipe is mounted in a seat coated with a titanium dioxide (Ti02) layer. United States Patent Specification No. 6,458,331 Bl proposes a computer input device sterilization apparatus which comprises a box open at one side which contains an ultraviolet source for irradiating a keyboard, mouse, trackball, touchpad or other computer input device when the box is placed over the device to be sterilized. A timer/power circuit is provided which activates the ultraviolet sterilization lamps as well as a recirculation fan for a specific period of time sufficient to achieve sterilization. In addition the apparatus includes an interlocking sterilization switch which is biassed in the "off" position so that, in the absence of a keyboard or the like, all lamps are off but which, when the box is placed over the keyboard or other input device, is closed so that power is provided to the lamps. In United States Patent Specification No. 6,278,122 Bl there is described a computer keyboard and mouse sterilizing system which has a cabinet and extendable base on a slidable rail mechanism for storage and support of a computer keyboard and mouse. There is an ultraviolet light source located inside the cabinet and a front door is hinged on the extendable base so that it can close the front of the cabinet when the extendable base and keyboard is slid into the cabinet. A safety interlock switch is mounted to the inside of the cabinet near to the opening of the front door so as to prevent operation of the ultraviolet lamp unless and until the base is in the retracted position and the front door is closed. Sterilization of an information processor is described in Japanese Patent Publication No. 07160362 A. This proposal utilises storage spaces for a computer keyboard and mouse with a sterilizing lamp and with a door. Upon closure of the door a sensor detects the storage of the keyboard and the mouse and a sterilizer lamp is automatically turned on. Then the lamp is automatically turned off after a prescribed sterilizing time set by a timer. Use of ultraviolet light for sterilization of telephone handsets is described in British Patent Specification No. 2 383 225 A. There is a need to provide an improved form of computer input apparatus for use in environments where risk of infection by bacteria and viruses is a particular problem, such as in hospital environments, including intensive care units where it is desirable that risk of infection, in particular by virulent microorganisms such as by methicillin-resistant Staphylococcus aureus (also known as MRSA) should be avoided as far as humanly possible. The present invention accordingly seeks to provide an improved form of computer input apparatus which ensures that scrupulous disinfection of a computer keyboard or the like computer input device can be carried out, thereby minimising the risk of a user of the apparatus unwittingly spreading infection by contact with a contaminated computer input device. According to the present invention there is provided computer input apparatus comprising a computer input device, ultraviolet light source means, the computer input device and the ultraviolet light source means being moveable relative to one another whereby an outer surface of the computer input device can be irradiated with ultraviolet light to disinfect it, and control circuit means adapted to monitor use of the computer input device by a user and, after a predetermined period of lack of use of the computer input device, to permit further use of the computer input device only after irradiation of the computer input device with ultraviolet light for disinfection thereof. The computer input device may be a computer keyboard, preferably a membrane keyboard. Such a keyboard may include a touchpad as a pointing device. It may alternatively comprise a computer mouse. In one preferred embodiment the ultraviolet source means is mounted on a support frame traversable over the computer keyboard while the computer keyboard remains substantially stationary. Thus the support frame may be arranged to run on guide rails mounted on the computer keyboard and wherein a servo mechanism is provided so as to cause the support frame to traverse over an operating face of the keyboard so as to enable irradiation of the operating surface. Alternatively the support frame can be arranged to run on guide rails mounted on the computer keyboard and to be manually moveable to cause the support frame to traverse over an operating face of the keyboard so as to enable irradiation of the operating surface.In such an arrangement in either case the guide rails may extend across a shorter dimension of the operating face while the support frame extends in the direction of a longer dimension of the computer keyboard. In such an apparatus the ultraviolet light source may be arranged to be activated upon expiry of the predetermined period of lack of use. In addition, the control circuit means may be arranged to disable the keyboard upon expiry of the predetermined period of lack of use, to detect when the support frame reaches the fully deflected position, and thereafter to re-enable use of the keyboard. In an alternative preferred embodiment the support means comprises a housing having an interior adapted to receive the computer keyboard, the computer keyboard being retractably mounted for movement into and out of the interior of the housing, while the ultraviolet light source is mounted in an upper part of the interior of the housing for irradiating an operating face of the computer keyboard when the computer keyboard is received within the interior of the housing. In such an embodiment the keyboard may be arranged to move into and out of the interior of the housing on guide rails. Alternatively the computer keyboard can be mounted on a tray arranged to move into and out of the interior of the housing on guide rails.Preferably in this embodiment the control circuit means is arranged to disable the keyboard upon expiry of the predetermined period of lack of use until the keyboard has been disinfected in readiness for further data entry. A switch means, for example a magnetic switch/position sensor, may be provided to detect when the keyboard has been inserted fully home into the housing and to signal to the control circuit that the keyboard is now ready for disinfection. In this case the control circuit is arranged so that, upon receiving an indication from the switch means that the keyboard is fully home, the ultraviolet light source is turned on for a preselected time, such as 15 seconds, so as to irradiate the upper surface of the keyboard and disinfect it. It is further preferred that upon expiry of the preselected time the keyboard is reenabled to permit further data entry. The computer input means according to the invention may include a plurality of light indicators for indicating the status of the computer input apparatus. For example, three light indicators may be provided for indicating respectively that the apparatus has been disinfected and is ready for use, that the apparatus requires disinfection and has been temporarily disabled, and that the apparatus is being disinfected. Preferably in this case the control circuit is further arranged to indicate by causing all three light indicators to flash simultaneously that the ultraviolet light source has failed. In order that the invention may be clearly understood and readily carried into effect two preferred embodiments thereof will now be described, by way of example only, with reference to the accompanying semi-diagrammatic drawings wherein:- Figure 1 is a perspective view of a first form of computer keyboard in accordance with the present invention; Figure 2 is a perspective view of the computer keyboard of Figure 1 with built-in controls and with the hood, which forms an ultraviolet lamp unit, removed; Figure 3 is a perspective view of the hood which houses the ultraviolet lamps; Figure 4 is a flowchart depicting a method of disinfecting a computer keyboard of the type illustrated in Figures 1 to 3; Figure 5 is a further flowchart of a method of disinfecting a modified form of the computer keyboard of Figures 1 to 3;Figure 6 is a perspective view of a second form of computer input apparatus according to the invention; Figure 7 is a further perspective view of the computer input apparatus of Figure 6 with the cover removed: Figure 8 is a plan view of the computer input apparatus of Figures 6 and 7 with the cover removed and with the keyboard withdrawn from the interior of the housing ready for use; Figure 9 is a block circuit diagram for the computer input apparatus of Figures 6 to 8; Figure 10 is a flow diagram illustrating a method of disinfecting the computer input apparatus of Figures 6 to 8; and Figure 11 is a further flow diagram showing a method of disinfecting a modified form of the computer input apparatus of Figures 6 to 8. Referring to Figures 1 to 3 of the accompanying drawings, a computer keyboard 1 in accordance with the invention comprises a flat membrane based keyboard 2 with a built-in UV light over it. The UV light (not shown) is housed in a hood 3 which extends over essentially the entire width of the keyboard 1 and is arranged to be movable along guides 4 provided one at each end of the keyboard 1. Preferably the ultraviolet light source is mounted within the hood 3 so as to lie closely adjacent to the upper surface of the keyboard 2 and the hood 3 is designed so as to shield as far as possible the ultraviolet light source so as to minimise the risk of ultraviolet light shining into a user's eyes.Thus the hood preferably comprises a metal shroud which has an opening of, for example, about half an inch (about 1.27 cm) on its underside for the ultraviolet light to fall directly on the keyboard 2. Suitably the ultraviolet light source comprises a pair of two ultraviolet tubes each rated at 5 to 6 watts, e.g. 5.3 watts. Keyboard 2 is a flat membrane keyboard, that is to say a computer keyboard whose operating surface is formed by a flat membrane of a suitable plastics material and whose "keys" are not separate, moving parts, as with the majority of other keyboards, but rather have only outlines and symbols printed on a flat, flexible surface. It is provided with low travel, tactile, low profile switches which are located underneath the printed outlines and symbols and which provide electrical contact when keytop areas are pressed. Such a keyboard is substantially free from crevices, nooks and crannies where bacteria and viruses can develop colonies and is also resistant against dirt and liquids. It can have its "keys" laid out in any convenient layout, for example one of the conventional "QWERTY" keyboard layouts conventionally used in the United States of America or in the United Kingdom.Other layouts may be appropriate for other countries. The "keys" can be printed with luminous ink so as provide an "autoglow" feature. A loudspeaker (not shown) is built into keyboard 2 and the control circuit is arranged so that a gentle "beep" is emitted by the loudspeaker as the user makes each keystroke. Underneath the "space bar" area 6 there are mounted five contact switches in parallel so that wherever the user's digit, often the user's thumb, hits the "space bar" 6 at least one of the contact switches is caused to close and thereby send a corresponding signal to the computer to which the keyboard 2 is connected. Keyboard 2 contains in its base a control circuit (not shown) which is able to detect activity and inactivity, that is to say it is able to detect keystrokes or the absence of keystrokes. It also contains a ballast (not shown) for the ultraviolet light source (not shown) within hood 3. A servo mechanism (not shown) is also housed with the base of keyboard 2. This mechanism may include a motor or motors which is or are arranged to drive reciprocally a pair of belts or chains, each of which is coupled to a downwardly projecting portion (not shown) of a respective end of hood 3 which is received in a corresponding one of the guides 4. By actuation of the motor or motors the hood 3 can be made to traverse across the upper surface of the keyboard 2. The ultraviolet tubes are preferably of the type sold as instant start germicidal lamps and are desirably made from fused silica. For example, tubes of this type are sold by Arklite Speciality Lamps Ltd. , of J-152, MIDC, Bhosari, Pune, Maharashtra, India. A ballast (not shown) for the ultraviolet light is also mounted in the base of keyboard 2. Power cables (not shown) for the ultraviolet light source within hood 3 are run through at least one of the aforementioned downwardly projecting portions. The method of use of the apparatus of Figures 1 to 3 is illustrated in Figure 4. As shown by step 100, upon turning on the power supply to the keyboard 2, the control circuit initialises all sensors which detect the position of the hood 3 relative to the keyboard 2 and, if necessary, resets the motor or motors to the start position, which is shown in Figure 1. This is step 101. The control circuit then detects in step 102 whether or not a keystroke has been made. If the keyboard is inactive, then it repeats the initialisation step 101, as indicated by line 103. If the control circuit detects keyboard activity, then according to line 104 it starts a timer 105 which is set to run for a pre-determined time, for example 1 minute.The control circuit then detects, as shown by step 106, whether there has or has not been keyboard activity during the period that the timer 105 has been running. If the keyboard has been used while the timer 105 has been running, then, as shown by line 107, the control circuit reverts to step 101. On the other hand, if there has been no keyboard activity during the period that timer 105 has been running, then, as shown by line 108, a second delay timer 109 begins to run for a period of two minutes. At the end of this two minute delay the control circuit activates the ultraviolet light or lights for a suitable period, for example 15 seconds.In addition, as indicated by step 110, the control circuit initialises the motor (or motors) for movement of the hood 3 forwards across the keyboard 2 so that, as the hood 3 moves over the keyboard 2, the ultraviolet light shines on the operating surface of the keyboard 2 to sterilise it. In experiments it has been shown that irradiation of a surface seeded with E coli cells with ultraviolet light with a wavelength of 254 nm produces a 99.9% kill of E coli at a dose of 90 J/m . Further experiments have demonstrated that, upon exposure of a flat membrane computer keyboard, which has been deliberately seeded with MRSA, to ultraviolet light of wavelength 254 nm, a 10 second exposure is sufficient to kill over 99.5% of the MRSA colonies. The unique features of computer input apparatus 1 are as given below; 1. No human intervention is necessary for cleaning; 2. There are substantially no crevices in the operating surface in which micro-organisms can incubate; 3. The apparatus operates automatically; 4. UV is a proven technology for disinfection; 5. The computer input apparatus 1 is compact in size; and 6. It enables simple, safe and sure disinfection. In summary, the keyboard 2 is a flat membrane based keyboard with minimum crevices with audio prompt for key stroke. The base of the keyboard 2 comprises the control electronics, the ballast, and the servo mechanism for movement of the hood 3. The hood 3 comprises two UV tubes rated 5.3 watts each. These are well encased in a metal shroud which has a half inch (1.27 cm) opening at the bottom for the UV light to fall directly on the keyboard 2. The edges have enough protection to ensure that there is no UV light visible to the naked eye. The intelligent electronics inside the keyboard sense the start of the keyboard activity and then waits for keyboard activity to stop. It waits for two minutes (this feature is configurable as per client requirement) after the last keystroke. The hood 3 then traverses across the length of the keyboard 2 and disinfects it with the UV light which comes on at full power. The hood 3 then returns to its original position and switches the UV tube to minimum power. This action is similar to a wiping action of an alcohol wipe after every keyboard use, except the fact that this is automatic. It will be appreciated by those skilled in the art that the periods for which timer 105 and the delay timer of step 109 run can be varied to suit the particular circumstances. Thus timer 105 can be made to run for a shorter or longer period than described above, e.g. from about 30 seconds to about 90 seconds, and so can the delay timer of step 109, which can run, for example, for a period of from about 30 seconds or less up to about five minutes or more. In a modification of the computer input apparatus 1 of Figures 1 to 3, the servo mechanism is omitted and the control circuit is designed so that, instead of automatically causing the hood 3 and UV lamps to traverse across the upper surface of the keyboard 2, it automatically disables the keyboard 2 so that any keystroke is not transmitted to the computer until the user disinfects the keyboard 2 by manually moving the hood 3 from its rearward rest position across substantially the whole of the upper surface of the keyboard 2. In this case the keyboard 2 is provided with a rest position sensor switch which is actuated if the hood 3 is moved away from its rest position at the rear of the keyboard 2. Also the hood 3 can be provided with a spring return mechanism so that the hood 3 returns automatically to its rearward rest position upon being released by the user.Moreover an end of travel contact switch or other form of detector is provided which is actuated only if the hood 3 completes its full range of travel before being released, such actuation serving to reenable the keyboard 2. The operation of this modified form of computer input apparatus is illustrated in Figure 5. When the power to the keyboard is turned on in step 200, the control circuit initialises the system. Steps 201 to 208 are essentially the same as steps 101 to 108 of Figure 4. However, instead of turning on the ultraviolet light, as occurs in step 109 of Figure 4, the control circuit in this case disables the keyboard 2 in step 209 so that a user cannot enter any further data into the computer until the keyboard 2 has been disinfected by being irradiated with ultraviolet light. The control circuit then looks to see if hood 3 is being moved in step 210 by detecting whether the hood 3 has moved away from its rest position sensor switch. If not, then it continues to check whether there has been any movement of hood 3 (see line 211).As soon as the control circuit detects that hood 3 is being moved it activates the ultraviolet light for a period of 15 seconds in step 212. Following completion of the forward stroke of the hood 3, as detected by the end of travel sensor switch and subsequent return of the hood 3 to its rest position, the control circuit re-enables the keyboard 2 to permit a user to enter further data to the computer and reverts to step 201. In Figures 6 to 8 there is illustrated a second form of computer input apparatus 11 in accordance with the invention. This comprises a cover 12 and a base 13 with a steel baseplate, the cover 12 and base 13 together forming a housing whose interior receives a flat membrane keyboard 14. The plastics material used for the upper surface of the flat membrane keyboard 14 desirably includes titanium dioxide (TiO2) with a view to reducing pollution by grease during handling. Although this is not indicated in Figures 6 and 7, the upper surface of flat membrane keyboard 14 is provided (as can be seen in Figure 8) with "keys" similar to those of keyboard 2 of the embodiment of Figures 1 to 3. As with the embodiment of Figures 1 to 3, the "keys" can be printed with luminous ink so as provide an "autoglow" feature.Also a loudspeaker can be built into keyboard 14, while the control circuit is arranged so that a gentle "beep" is emitted by the loudspeaker as the user makes each keystroke. Underneath the "space bar" area of keyboard 14 there are mounted five contact switches in parallel so that wherever the user's digit, often the user's thumb, hits the "space bar" area at least one of the contact switches is caused to close and thereby send a corresponding signal to the computer to which the keyboard 14 is connected. Keyboard 14 is mounted like a drawer on base 13 and is provided with guides or runners (not shown) similar to the guides or runners of a conventional filing cabinet or of a drawer in a fitted kitchen. It will be appreciated by those skilled in the art that in Figure 8 the cover 12 has been omitted (apart from a display panel which will be described below). On base 13 there are mounted a pair of brackets 15, 16 which each bear end connections 17 for receipt of corresponding the ends of a pair of conventional ultraviolet germicidal light tubes 18, for example, tubes similar to those available from Arklite Speciality Lamps Ltd., of J152, MIDC, Bhosari, Pune, Maharashtra, India. These are connected by electrical leads 19 to a ballast 20 which is provided with a UV tube fail sensor and which is connected to a mains inlet 21 for connection to a conventional electrical mains supply, for example a 230 volt 50 Hz mains supply. Ballast 21 is also connected by a control cable 22 (see Figure 6) to a control circuit box 23 which contains an appropriate printed circuit board having the desired electronic circuit thereon.From control circuit box 23 there emerge also PS/2 cables 24, 25 for connecting the keyboard 14, and a touchpad 26 (see Figure 6) incorporated in the keyboard 14, respectively to a computer. At the rear of the housing there is a magnetic switch and position sensor 27 which is connected to control circuit box 23 by cable 28. This magnetic switch and position sensor 27 detects when the keyboard 14 has been pushed back into the interior of the housing in readiness for disinfection. A display panel 29 is provided on cover 12 and is connected to control circuit box 23 by means of cable 30. This is provided with three LEDs 31, 32, and 33 which light up to indicate the current status of the computer input apparatus 11. Suitable wording appears adjacent each of the three LEDs 31, 32, and 33. Thus the word "DISINFECTING" appears next to LED 31, while the legends "READY TO USE" and "USED" appear beside LEDs 32 and 33 respectively. As can be seen from Figure 8 keyboard 14 is provided with a series of touch pads 34 corresponding, for example, to those of a conventional "QWERTY" keyboard as well as a touchpad 26, which takes the place of a conventional computer mouse. Keyboard 14 is connected to control circuit box 23 by means of cable 35. On the front of the keyboard 14 there is a copper strip 36. By pushing on copper strip 36 a user can trip the magnetic switch and position sensor 27 to cause the keyboard 14 to be pushed out a short distance on its guide rails from the interior of the housing to enable the user then to pull it fully out into the operating position. It also serves for pushing the keyboard 14 back into the housing again until it re-engages with the magnetic switch and position sensor. Copper is used as the material from which strip 36 is made because it has been shown that it is a material upon which bacteria and viruses do not tend to multiply. In a modification of the computer input apparatus of Figures 6 to 8 copper strip 36 extends the full width of the front of keyboard 14. Figure 9 is a block diagram of the internal circuitry of computer input apparatus 11. Reference numeral 37 indicates a conventional personal computer (PC)/network interface for a keyboard and mouse (or touchpad). In use of the computer input apparatus 11 of Figures 6 to 9, the user first checks the LED indications on the top of the apparatus 11. If keyboard 14 has been disinfected and hence is substantially sterile and ready for use, then LED 32 will be lit, indicating that the apparatus is "READY FOR USE". The user can accordingly then nudge copper strip 36 so as to cause the keyboard 14 to be partially ejected from the housing in readiness for entry of data. The control circuit will have enabled the touch keys 34 so that signals resulting from the user's keystrokes will be received by the computer. As shown in Figure 10 when the power to the keyboard 14 is turned on, as indicated by step 301, the control circuit initialises the system in step 302 and then checks whether the keyboard is active in step 303. If no keystrokes have been recorded and the keyboard 14 is inactive, then the control circuit returns to step 402 as indicated by line 304. On the other hand when the control circuit detects keyboard activity, it starts a timer which runs for a predetermined period of between about 10 and about 90 seconds, for example about 60 seconds. If at the end of this predetermined period the control circuit has detected any keyboard activity in step 306, then it reverts to step 302 as indicated by line 307.On the other hand if the keyboard 14 has not been used within this predetermined period, then as indicated by line 308 the control circuit disables the keyboard 14 in step 309 so that a user can no longer enter data into the computer. Also LED 33 is illuminated to indicate the condition "USED", i.e. that the keyboard 14 now needs disinfection. The control circuit monitors the position of keyboard 14 in step 310. If the keyboard 14 has not been pushed back into its housing, then the control circuit returns to steps 309 and 310 as indicated by line 311. On the other hand if the control circuit detects that keyboard 14 has been pushed back into its housing as result of keyboard 14 reaching its fully closed position and activating magnetic switch and sensor 27, then it proceeds to step 312 to commence irradiation with ultraviolet light.In step 312 it is only necessary to activate one of the ultraviolet tubes 18. (Only the forward ultraviolet tube 18 is used at any one time, the rearward one being immediately available on standby in case of failure of the forward tube 18). In step 312 the operating surface of keyboard 14 is irradiated for a period sufficient to disinfect it, for example a period of about 15 seconds. At the same time LED 33 is extinguished and instead the LED 31 is illuminated during this period adjacent the word "DISINFECTING", thus indicating to a potential user that the keyboard 14 is being disinfected. After the period of disinfection is completed the control circuit re-enables the keyboard 14 so that it is again ready for user input and returns to step 302.At the same time LED 31 is extinguished and LED 32 is lit against the words "READY TO USE" in order to indicate to a potential user that the keyboard 14 is ready for user input. Conveniently the LEDs 331, 32, and 33 have different colours; for example, LED 31 can be blue, LED 32 can be green, and LED 33 can be red. If both ultraviolet tubes 18 should have failed then the control circuit causes all three LEDs 31, 32, and 33 to flash and automatically re-enables the emergency use of the keyboard 14. Users need to be aware that, if all three LEDs should be flashing, then any user needs to revert to use of alcohol wipes for disinfection until such time as the ultraviolet tubes 18 can be replaced. It is preferred that, if possible, the control circuit should be arranged, in the event of a failure of a tube 18, to send a message automatically to the maintenance staff via the hospital's network to alert them that the computer input apparatus requires maintenance. In a modification of the computer input apparatus of Figures 6 to 9, the keyboard is mounted in the housing using a mechanism similar to that found in many designs of audio CD or DVD players whereby a gentle nudge on the front of the tray or on an ejection button for the CD or DVD automatically actuates a servo mechanism which causes the tray to open to permit a CD or DVD to be inserted or removed. Such a mechanism can also be made to retract the keyboard 14 into the housing under the control of the control circuit. Figure 11 illustrates how such a modification operates. Upon turning the power on in step 401, the control circuit in this case initialises the system in step 402 and then proceeds to check whether there is any keyboard activity in step 403. If there is none, then it reverts to step 402 as indicated by line 404.On the other hand if keyboard activity is detected, then the timer 405 is started and runs for a predetermined period, for example 60 seconds. In step 406 the control circuit checks whether there has been any keyboard activity during this period. If there has been such activity then, as indicated by line 407, the control circuit reverts to step 402. On the other hand if there is no keyboard activity during this period, then the control circuit proceeds in step 408 to disable the keyboard, to retract it, and then irradiate it with ultraviolet light, while the LEDs 33, 31, and 32 are illuminated in turn. Thereafter, when LED 32 is lit, the control circuit reverts to step 403 as shown by line 409.

Claims

CLAIMS:

1. Computer input apparatus comprising a computer input device, ultraviolet light source means, the computer input device and the ultraviolet light source means being moveable relative to one another whereby an outer surface of the computer input device can be irradiated with ultraviolet light to disinfect it, and control circuit means adapted to monitor use of the computer input device by a user and, after a predetermined period of lack of use of the computer input device, to permit further use of the computer input device only after irradiation of the computer input device with ultraviolet light for disinfection thereof.

2. Computer input apparatus according to claim 1, wherein the computer input device is a computer keyboard.

3. Computer input apparatus according to claim 2, wherein the computer keyboard is a membrane keyboard.

4. Computer input apparatus according to claim 2 or claim 3, wherein the keyboard includes a touchpad as a pointing device.

5. Computer input apparatus according to any one of claims 2 to 4, wherein the ultraviolet source means is mounted on a support frame traversable over the computer keyboard while the computer keyboard remains substantially stationary.

6. Computer input apparatus according to claim 5, wherein the support frame is arranged to run on guide rails mounted on the computer keyboard and wherein a servo mechanism is provided so as to cause the support frame to traverse over an operating face of the keyboard so as to enable irradiation of the operating surface.

7. Computer input apparatus according to claim 5, wherein the support frame is arranged to run on guide rails mounted on the computer keyboard and to be manually moveable to cause the support frame to traverse over an operating face of the keyboard so as to enable irradiation of the operating surface.

8. Computer input apparatus according to claim 6 or claim 7, wherein the guide rails extend across a shorter dimension of the operating face and wherein the support frame extends in the direction of a longer dimension of the computer keyboard.

9. Computer input apparatus according claim 8, wherein the ultraviolet light source is arranged to be activated upon expiry of the predetermined period of lack of use.

10. Computer input apparatus according to claim 8 or claim 9, wherein the control circuit means is arranged to disable the keyboard upon expiry of the predetermined period of lack of use, to detect when the support frame reaches the fully deflected position, and thereafter to re-enable use of the keyboard.

11. Computer input apparatus according to any one of claims 2 to 4, wherein the support means comprises a housing having an interior adapted to receive the computer keyboard, wherein the computer keyboard is retractably mounted for movement into and out of the interior of the housing, and wherein the ultraviolet light source is mounted in an upper part of the interior of the housing for irradiating an operating face of the computer keyboard when the computer keyboard is received within the interior of the housing.

12. Computer input apparatus according to claim 11, wherein the keyboard is arranged to move into and out of the interior of the housing on guide rails.

13. Computer input apparatus according to claim 11, wherein the computer keyboard is mounted on a tray arranged to move into and out of the interior of the housing on guide rails.

14. Computer input apparatus according to any one of claims 10 to 13, wherein the control circuit means is arranged to disable the keyboard upon expiry of the predetermined period of lack of use until the keyboard has been disinfected in readiness for further data entry.

15. Computer input apparatus according to claim 14, wherein a switch means is provided to detect when the keyboard has been inserted fully home into the housing and to signal to the control circuit means that the keyboard is now ready for disinfection.

16. Computer input apparatus according to claim 15, wherein the switch means comprises a magnetic switch/position sensor.

17. Computer input apparatus according to claim 15 or claim 16, wherein the control circuit means is arranged so that, upon receiving an indication from the switch means that the keyboard is fully home, the ultraviolet light source is turned on for a preselected time so as to irradiate the upper surface of the keyboard and disinfect it.

18. Computer input apparatus according to claim 17, wherein upon expiry of the preselected time the keyboard is reenabled to permit further data entry.

19. Computer input means according to any one of claims 11 to 18, wherein a plurality of light indicators is provided for indicating the status of the computer input apparatus. 19. Computer input apparatus according to claim 18, wherein three light indicators are provided for indicating respectively that the apparatus has been disinfected and is ready for use, that the apparatus requires disinfection and has been temporarily disabled, and that the apparatus is being disinfected.

20. Computer input apparatus according to claim 19, wherein the control circuit is arranged to indicate by causing all three light indicators to flash simultaneously that the ultraviolet light source has failed.