GB2474094A

GB2474094A - Lone worker alarm system

Info

Publication number: GB2474094A
Application number: GB201012836A
Authority: GB
Inventors: Phillip John Bunting
Original assignee: CAMWATCH Ltd
Current assignee: CAMWATCH Ltd
Priority date: 2009-07-31
Filing date: 2010-07-30
Publication date: 2011-04-06
Also published as: GB0913371D0; GB201012836D0

Abstract

A lone worker panic alarm system 1 is disclosed comprising: a network of at least two RFID interrogator devices 130a-s within a building 100. The system further comprises a lone worker alarm unit 10 including an alarm activator 16 configured to send an alarm signal when activated, and an RFID tag arranged to communicate with the network so that the alarm system 1 has a record of the last known location of the alarm unit 10. The system 1 is configured to receive the alarm signal, and to discover and output the last known location of the lone worker alarm unit 10. In this way, a reliable indication as to the whereabouts of a lone worker located indoors can be determined. In a further embodiment the system 1 may be integrated with a CCTV sub-system.

Description

LONE WORKER SECURITY SYSTEM

BACKGROUND

Technical Field

The invention relates to a lone worker security system and in particular to a lone worker security system for use indoors.

Description of Related Art

Lone workers are often exposed to a significant level of threat, and often work indoors.

For example, nurses in hospitals, teachers in classrooms, security staff within buildings, students on campuses and cleaners in hotels are all examples of lone workers operating indoors.

Lone worker panic alarm devices already exist. The current generation of devices is based on mobile phone technology, to raise an alarm, combined with Global Positioning System (GPS) capability, which uses satellite tracking to identify the location of the lone However, the known systems only work outdoors and are not usable indoors. Currently there is no lone worker security system that can locate a lone worker within a building.

Because the location of a lone worker cannot be determined reliably indoors, there is no useful follow-up action available once an alarm has been activated. Any response to the alarm would be slow and uncertain, relying on an operator in a monitoring station to interpret the circumstances of the alarm and to send a responder to try and find, then assist, the lone An aim of the invention is to provide a lone worker security system able to locate lone Another aim of the invention is to provide a useful follow-up action, once a lone worker in distress has been located.

SUMMARY OF THE INVENTION

In summary, the invention provides a lone worker alarm system which uses RFID technology to solve the problem of identifying the location of a lone worker within a building.

Additionally, in one aspect, the invention integrates selective CCTV recording to provide evidence of pre-and post-alarm activity, and to allow a remote operator to locate the lone worker more precisely, and to provide immediate support.

According to the present invention there is provided an apparatus and method as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows.

In one aspect of the invention, there is provided a lone worker alarm system comprising: a network of at least two RFID interrogator devices located within a building; a lone worker alarm unit comprising an alarm activator configured to send an alarm signal when activated; and an RFID tag arranged to communicate with the network so that the lone worker alarm system has a record of the last known location of the lone worker alarm unit; wherein the system is configured to receive the alarm signal and to discover and output the last known location of the lone worker alarm unit.

In this way, a reliable indication as to the whereabouts of a lone worker located indoors can be determined. Further assistance can then be dispatched in a more efficient manner.

Preferably, the lone worker alarm unit is arranged to send the alarm signal over a wireless link. Preferably, the lone worker alarm unit is arranged to send the alarm signal over a telecommunications network. Preferably, the telecommunications network is one of a GSM or 3G telecommunications network.

Preferably, the last known location is determined based on a time stamp recording the time the RFID tag last communicated with one of the RFID interrogator devices, and location information of the RFID interrogator device which last communicated with the RFID tag. In this way, a relatively simple and elegant system is employed which can easily determine the approximate location of the lone worker alarm unit, and hence the lone worker.

Preferably, the lone worker alarm system comprises a database arranged to store information relating to the position of each RFID interrogator within the building, and to store information relating to the time each RFID interrogator communicates with the RFID tag so that the last known location of the lone worker alarm unit can be discovered. Preferably, the database is located in the building.

Preferably, the lone worker alarm system comprises a receiving station arranged to communicate with each RFID interrogator. Preferably, the receiving station is arranged to communicate wirelessly with each RFID interrogator. Preferably, the receiving station is arranged to receive the alarm signal. Preferably, the receiving station is located in the building.

Preferably, the lone worker alarm system comprises an alarm notification unit arranged to output the last known location of the lone worker alarm unit when the alarm signal is received by the receiving station. Preferably, the alarm notification unit is located in the building.

Preferably, the system comprises a CCTV sub-system comprising a network of CCTV installations. In this way, a more precise location of the lone worker can be identified quickly, and evidence of the alarm situation can be recorded. Preferably, the network of CCTV installations corresponds to the network of RFID interrogators, so that at least one CCTV installation is provided for each RFID interrogator. In this way, video images from the last known zone, or neighbouring zones, can be quickly identified, recorded and displayed.

Preferably, each CCTV installation includes at least one camera, a microphone, a loudspeaker and a communications unit arranged to transmit data and receive data. The video is only recorded into long-term memory at the point at which the alarm signal is received in order to protect the privacy of the occupants of the building.

Preferably, the CCTV sub-system is arranged to buffer video from each CCTV installation for a predetermined overwrite period when no alarm signal has been generated.

Preferably, the overwrite period is between around 1 minute and 10 minutes. Most preferably, the overwrite period is 10 minutes. Preferably, the video is buffered in a memory local to each CCTV installation. Alternatively, the video is buffered in a memory external from each CCTV installation. In this way, useful pre-alarm video can be preserved, without impacting unduly on the privacy of the occupants of the building.

Preferably, the lone worker alarm system comprises a remote monitoring centre. In this way, a useful back-up, or centralised control operation, is achieved.

Preferably, the lone worker alarm system is arranged to record data from one or more selected CCTV installations when the alarm signal is generated. Preferably, each selected CCTV installation is arranged to transmit video to a digital video recorder when the alarm signal is generated. Preferably, the system is arranged to send buffered data from the one or more selected CCTV installations to the digital video recorder when the alarm signal is generated. Preferably, the lone worker alarm system is arranged to select the CCTV installation associated with the last known location of the lone worker alarm unit. Preferably, one or more neighbouring CCTV installations are also selected when the alarm signal is generated. In this way, if accidental detection occurs, in other words, if an RFID interrogator in an adjacent zone detects the lone worker alarm unit 10, video data from the correct zone is more likely to be recorded and displayed, to aid an operator identify the precise location of the lone worker. Preferably, the digital video recorder is located in the building. Preferably, the digital video recorder is located remote from the building at the remote monitoring centre.

Preferably, there are two digital video recorders, one located in the building, and one located in the remote monitoring centre.

Preferably, the lone worker alarm system is arranged to relay video being recorded by the digital video recorder to an output screen, preferably in the remote monitoring centre.

Preferably, the lone worker alarm system is arranged to de-select certain CCTV installations after the alarm signal has been received so that only video pertinent to the alarm is recorded.

Preferably, the lone worker alarm system is arranged to record, long-term, video from all, or selected, CCTV installations during pre-selected time periods. Additionally, the lone worker alarm system may be configured to record video from specific pre-selected high risk locations even when an alarm is not raised. Preferably, the recorded video is automatically overwritten a predetermined time after recording. Preferably, the predetermined time is between I day and 3 months. Most preferably, the predetermined time is 1 month. In this way, a medium-term recording length of video data can be achieved for specific situations only, such as lunchtimes at schools, when children are largely unsupervised.

Preferably, the lone worker alarm system is arranged to record video from all CCTV installations, and to record all buffered video, when a high-level alarm is raised. Preferably, the high-level alarm is caused by a panic button, or master button. Preferably, the panic button, or master button, can be activated from the building. Additionally, or alternatively, the or a panic button or master button can be activated from the remote monitoring centre.

Preferably, the high-level alarm is raised by a fire alarm or a burglar alarm in the building. In this way, useful video evidence can be gathered and preserved during emergency situations, when privacy is not an issue.

Preferably, the lone worker alarm unit comprises an intermediate alarm activator configured to send a video recording request signal when activated, which causes the system to record video from selected CCTV installations depending on the location of the lone worker alarm unit, but which does not raise an alarm.

According to another aspect of the invention, there is provided a method of locating a lone worker, the method comprising: monitoring a lone worker alarm unit having an RFID tag using a network of RFID interrogators spread throughout a building and recording the last known location of the lone worker alarm unit; sending an alarm signal from the lone worker unit; and, upon receiving the alarm signal, discovering and outputting the last known location of the lone worker alarm unit.

For brevity, the reader will understand that the preferred features listed above for the first aspect of the invention relating to the system are applicable, where appropriate, to the method.

According to another aspect of the invention, there is provided a lone worker alarm unit comprising: an RFID tag for communication with a network of RFID interrogators located within a building; an alarm activation button for sending an alarm signal; and an alarm notification unit for sending the alarm signal to an alarm monitoring apparatus.

Preferably, the alarm notification unit is arranged to transmit the alarm signal wirelessly.

Preferably, the alarm notification unit is arranged to transmit the alarm signal wirelessly over a telecommunications network. Preferably, the alarm notification unit is arranged to transmit the alarm signal wirelessly over a GSM or 3G telecommunications network.

At least some of the exemplary embodiments may be constructed, partially or wholly, using dedicated special-purpose hardware. Terms such as component', module' or unit' used herein may include, but are not limited to, a hardware device, such as a Field Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC), which performs certain tasks. Also, elements of the exemplary embodiments may be configured to reside on an addressable storage medium and be configured to execute on one or more processors. That is, some of the exemplary embodiments may be implemented in the form of a computer-readable storage medium having recorded thereon instructions that are, in use, executed by a computer system. The medium may take any suitable form, but examples include solid-state memory devices (ROM, RAM, EPROM, EEPROM, etc.), optical discs (e.g. Compact Discs, DVDs, Blu-Ray discs and others), magnetic disks such as hard disks, magnetic tapes and magneto-optic storage devices. In some cases the medium is distributed over a plurality of separate computing devices that are coupled by a suitable communications network, such as a wired network or wireless network. Thus, functional elements of the invention may in some embodiments include, by way of example, components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Further, although the exemplary embodiments have been described with reference to the components, modules and units discussed below, such functional elements may be combined into fewer elements or separated into additional elements.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention, and to show how exemplary embodiments may be carried into effect, reference will now be made to the accompanying drawings in which: Fig. 1 is a schematic view of a lone worker security system 1 according to a first embodiment of the invention; Fig. 2 is a schematic diagram showing the system of Fig. 1 in more detail; Fig. 3 is a schematic view of a second embodiment of the invention; and Fig. 4 is a schematic diagram showing the system of Fig. 3 in more detail; Fig. 5 is another schematic drawing of the system of Fig. 3; Fig. 6 is a schematic diagram showing the main components of a monitoring station shown in Fig. 5; Fig. 7 is a flowchart showing a method for detecting the location of a lone worker alarm unit according to the first and second embodiments of the invention; Fig. 8 is a flowchart showing a method of activating an alarm according to the first and second embodiments of the invention; Fig. 9 is a flowchart showing an alarm activation method according to the second embodiment of the invention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Two embodiments of the invention are now described with reference to the accompanying drawings, in which like reference numerals denote like items.

The first embodiment of the invention is described with reference to Fig. 1, which is a schematic view of a lone worker security system 1.

The system 1 comprises a lone worker alarm unit 10 able to raise an alarm, and a building 100 in which a lone worker carrying the lone worker alarm unit 10 is normally located during working hours.

The lone worker alarm unit 10 is arranged to be able to raise an alarm when the lone worker needs assistance. In this example, the lone worker alarm unit 10 is arranged to raise an alarm via a wireless communication channel, and in particular a mobile GSM telecommunications network 50. However, any form of communication channel would be adequate, whether wireless or wired, direct or via a network, depending on the application.

The lone worker alarm unit 10 in this example is portable and is uniquely associated with the lone worker.

In this example, the building 100 is a school comprising a ground floor 110 and a first floor 120. On the ground floor 110 is an assembly hall llOa, a corridor hUb, a stairwell hOc and an entry/exit point 112. The second floor 120 comprises a corridor 120d, a first classroom 120e and a second classroom 120f. Of course, the system could be employed in other types of building, or indeed across multi-building sites.

The building 100 is split into six zones as follows, in addition to the entry/exit point 112: Zone A -assembly hall llOa; Zone B -corridor 1 lOb; Zone C -stairwell hOc; Zone D -corridor 120d; Zone E -first classroom 120e; and Zone F -second classroom 1 20f.

The lone worker alarm unit 10 is also arranged to communicate using RFID (radio-frequency identification) technology. Correspondingly, each of the above-indentified zones A-F in the building 100 comprises an RFID interrogator able to detect the lone worker alarm unit 10. In practice, the system will include many lone worker alarm units 10, and each lone worker alarm unit 10 will have a unique RFID tag having a unique ID allowing each lone worker alarm unit 10 to be uniquely indentified.

In more detail, there is provided seven RFID interrogators 130a-f located in zones A-F.

Zone B is the corridor 120b and comprises two entry/exit points 112 at either end thereof.

Correspondingly, zone B comprises two RFID interrogators 130b, each located adjacent the respective entry/exit points 112. Each of zones A and C-F comprise a single RFID interrogator 130a and 130c-f, respectively.

Each RFID interrogator is of a suitable type already known to those in the art. Each RFID interrogator must be able to detect a lone worker alarm unit 10 at a distance ranging up to 25 metres or more depending on the application. In most applications, a maximum range of 5 metres to 15 metres is suitable. The lone worker alarm unit 10 has an active RFID tag, a battery assisted RFID tag, or any other suitable RFID tag, to ensure a sufficient range is available for the application. In some specific low-range applications, the lone worker alarm unit 10 may carry a passive RFID tag. The RFID interrogators 130b are arranged to detect entry and exit from the building 100.

The ground floor 110 also comprises a control room 114 which is arranged to receive signals from each of the RFID interrogators 130a-f located throughout the building 100. The control room 114 is arranged to store information relating to the zone of each RFID interrogator 130a-f and information on when the lone worker alarm unit 10 is detected by each of the RFID interrogators 130a-f. In practice, this is done by associating the unique ID of the RFID tag with a time stamp to indicate the last detected time of the lone worker alarm unit 10 at a particular RFID interrogator 130a-f.

The lone worker alarm unit 10 is arranged to send an alarm signal, when necessary, via the GSM telecommunications network 50 as mentioned above. The control room 114 is arranged to receive the alarm signal via the GSM telecommunications network 50 and to determine which zone the lone worker alarm unit 10 was most recently detected in from the information discussed in the paragraph above. Then, an alarm notification is output which includes the last known location of the lone worker alarm unit 10 based on the latest time stamp associated with the lone worker alarm unit 10 and corresponding RFID interrogator 130a-f.

Fig. 2 is a schematic diagram showing the system of Fig. 1 in more detail. In particular, Fig. 2 shows zone E (classroom 120e) and the control room 114 in more detail.

The control room 114 comprises a receiving station 115, a controller 116, a database 117, and an alarm notification unit 118.

The receiving station 115 is arranged to receive information from each of the RFID interrogators 130a-f. In this example, the RFID interrogators 130a-f are arranged to communicate wirelessly with the receiving station, however, any form of communication channel would be adequate, whether wireless or wired, direct or via a network.

The information from each of the RFID interrogators 130a-f comprises the unique ID from the RFID tag of the lone worker alarm unit 10, as and when detected by one of the RFID interrogators 130a-f. The unique ID is recorded together with a time stamp indicating when the lone worker alarm unit 10 was detected by the particular RFID interrogator 130a-f.

The controller 116 is arranged to store the unique ID, time stamp and location of the relevant RFID interrogator 130a-f in the database 117. The receiving station 115 is also arranged to receive an alarm signal from the lone worker alarm unit 10 via the GSM telecommunications network 50. In this case, upon receipt of the alarm signal, the controller 116 is arranged to interrogate the database 117 for the last known location for the lone worker alarm unit 10 and to output an alarm, by way of an audible and visual warning, using the alarm notification unit 118. The alarm notification unit 18 outputs the last-known location of the lone worker alarm unit 10 retrieved from the database 117, in terms of one of zones A-F.

Fig. 3 is a schematic view of a second embodiment of the lone worker security system 1 ofFig.1.

The lone worker security system 1 of the second embodiment is similar to the first embodiment, but has the following differences, additional components and functionality.

Firstly, the lone worker security system 1 is integrated with a CCTV (closed circuit television) sub-system. The CCTV sub-system comprises seven CCTV installations 140a-f located in each of zones A-F, respectively, to correspond to the RFID interrogators 130a-f. As described with reference to the first embodiment, one zone, that is zone B, comprises two entry/exit points 112 at either end thereof. Correspondingly, zone B comprises two CCTV installations 140b, each located adjacent the respective entry/exit points 112. Each of zones A and C-F comprise a single CCTV installation 140a and 140c-f, respectively.

Fig. 3 shows a typical CCTV installation 150, located at one of the entry/exit points 112.

The typical CCTV installation 150 comprises a digital video camera 152, a microphone 154, a loudspeaker 156 and a communications unit 158 for receiving commands and relaying video and audio information via a wireless connection.

The CCTV sub-system is arranged to buffer video from each CCTV installation 140a-f continuously on a short cycle having a predetermined overwrite period. In other words, all recorded video is overwritten periodically during normal operation of the system 1. Normally, the overwrite period is between 1 minute and 10 minutes, but any sensible overwrite period may be employed depending on the application. This is an example of short-term video storage. In this embodiment, the video is buffered in memory locally in each digital video camera 152; however, any form of buffering or short term recording may be employed, for example by using a digital video recorder or a networked video recorder. There could be any means of fixed or removeable storage located at any suitable point in the building 100 or system 1.

Also, in the second embodiment shown by Fig. 3, there is a remote monitoring station 200 which is arranged to receive the alarm signal from the lone worker alarm unit 10, and which is arranged to receive location information relating to the movement of the lone worker alarm unit 10 as discussed in relation to the first embodiment, and to receive video information from the CCTV sub-system in response to the alarm signal. In this embodiment, the remote monitoring station 200 is arranged to communicate wirelessly with the alarm unit 10 to receive the alarm signal directly via the GSM telecommunications network 50, and is arranged to relay the alarm signal to the control room 114. However, the alarm signal could be relayed by the control room 114 to the remote monitoring station 200, or the control room 114 and the remote monitoring station could receive the alarm signal independently of one another. Also, the remote monitoring station 200 is arranged to communicate wirelessly with the control room to receive the video information, and to pass control commands to the CCTV sub-system. Of course, the communications need not be wireless, and could be hard-wired or employ any other suitable communications method.

The remote monitoring station 200 is also arranged to maintain a database of last-known locations of the lone worker alarm unit 10, raise an alarm upon receipt of the alarm signal, record video from the CCTV sub-system upon receipt of the alarm signal, display the video, establish a voice channel with each CCTV installation 140a-f, and output the last known location of the lone worker alarm unit 10. The remote monitoring station 200 can effectively replace much of the functionality of the control room 114, or act in parallel to provide a back-up service, depending on the application.

Figs. 4 to 6 are schematic diagrams showing the system of Fig. 3 in more detail.

Specifically, Fig. 4 shows the control room 114 and remote monitoring station 200.

In the second embodiment, the control room 114 additionally comprises a CCTV hub 159, and a communications server 119. In the example shown, the controller 116, the database 117, and the alarm notification unit 118 remain in the control room 114 to provide local operational support, however these components are optional where repeated in the remote monitoring station 200 and in some applications are not employed locally in the control room 114.

The receiving station 115 is arranged to receive the unique ID of the lone worker alarm unit 10 from each of the RFID interrogators 130a-f as discussed above in relation to the first embodiment The CCTV hub 159 is arranged to receive and transmit data to each of the CCTV installations 140a-f, including commands to pan, zoom and tilt each camera, a command to transmit video and audio from each camera and microphone, respectively, a command to save and transmit buffered video and audio data, and voice data to be output by each loudspeaker.

The communications server 119 is arranged to establish communication with the remote monitoring station 200 via a 3G telecommunications network 60, or the GSM telecommunications network 50, as appropriate, to exchange data, such as location and control commands. The communications server 119 is arranged to use the 3G telecommunications network 60 for video transmissions.

The remote monitoring station 200 (see especially Figs. 4 and 6) comprises a communications module 202, a controller 204, a database 206, a digital video recorder 208, a TV display panel 210, a microphone 212, and an alarm notification unit 214.

The communications module 202 is arranged to communicate with the lone worker alarm unit 10 via the GSM telecommunications network 50 so as to receive the alarm signal.

The communications module 202 is also arranged to communicate with the communications server 119 in the control room 114 via the 3G telecommunications network 60, or GSM telecommunications network 50, as appropriate, to receive video information from the CCTV sub-system, and to relay information and commands from the remote monitoring station 200 back to the CCTV sub-system. The controller 204 is arranged to control components of the remote monitoring station 200.

The database 206 is the same as the database 117 of the control room 114, but when the remote monitoring station 200 is used, the database 117 is duplicated by database 206 in the remote monitoring station 200 as shown, or is replaced by the database 206.

The digital video recorder 208 is arranged to record video from the CCTV sub-system when an alarm is raised, and to record the buffered video from the CCTV sub-system to create time-limited pre-alarm video evidence. The recorded video on the digital video recorder 208 is stored until deleted by a user, and is an example of long-term video storage.

Likewise, the TV display panel 210 is arranged to output video signals from the CCTV sub-system and in particular selected ones of the CCTV installations 140a-f when an alarm is raised.

The microphone 212 is used to establish a voice channel with a corresponding one of the CCTV installations 140a-f, 150 via a microphone 154 and loudspeaker 156 within the CCTV installation 140a-f, 150.

The alarm notification unit 214 is the same as the alarm notification unit 118 located in the control room 114. Again, one or both alarm notification units may be employed, depending on the application.

Referring now to Fig. 5, the lone worker alarm unit 10 is shown to comprise a GSM module 12 for communicating with the GSM telecommunications network 50, an RFID module for communicating with the RFID interrogators 130a-f, and an alarm button 16 for raising an alarm via the GSM telecommunications network 50.

Each of zones A-F is shown in communication with the receiving station 115 and CCTV hub 159, both of which are located in the control room 114. In this example, the lone worker alarm unit 10 is shown to have communicated most recently with the RFID interrogator 130e of zone E. Also, the alarm button 16 has been activated, and the alarm signal has been sent to the remote monitoring station 200 via the GSM telecommunications network 50. The controller 204 interrogates the database 206 for the last known location, and causes a command to be sent to the CCTV installation 140e in zone E to begin relaying video data to the remote monitoring station 200, via the CCTV hub 159. Also, the command, or a separate command, causes locally buffered video to be sent through to the remote monitoring station 200 so that some pre-alarm footage is available for later examination. The video received from zone E is recorded in the digital video recorder 208 and is simultaneously displayed on the TV display panel 210. A voice channel is established between the microphone 212 in the remote monitoring station 200 and the loudspeaker 156 in CCTV installation 140e so that, if necessary, voice communication can be established with the lone worker. Additionally, the alarm notification unit 214 alerts an operator to the alarm with a visual and audible warning.

In this example, the digital video recorder 208 is used to record the video data once an alarm has been raised, however, any method of recording may be employed, for example by using a networked video recorder. There could be any means of fixed or removeable storage located at any suitable point in the building 100 or system 1.

In some cases, the system 1 may activate CCTV installations adjacent zone E, to compensate for errors by RFID interrogators 130a-f. This is because an RFID interrogator in a zone adjacent the lone worker alarm unit 10 may inadvertently receive a signal if the RFID tag is within range. The operator in the remote monitoring station 200 is then able to determine in which zone the lone worker is in, visually from the received video, in this example from zone E and adjacent zones. To help here, the database 206 is also arranged to store an image of the lone worker associated with the lone worker alarm unit 10, and the voice channel from the remote monitoring station 200 is opened with all active CCTV installations so that audible descriptions of the lone worker's whereabouts may be used.

The above discussion of the second embodiment of the invention describes one example of how CCTV can be integrated with RFID location technology to create a lone worker alarm system 1 having improved responses. One important obstacle in relation to realising the invention is concerns over privacy. The building 100 in this example is a school, and there is considerable resistance to the use of CCTV in schools. By using short-term memory buffering and activating only relevant cameras based on lone worker location, the privacy argument can be overcome and the advantages of the CCTV sub-system can be realised in practice. Only when an alarm is raised does the system 1 turn the buffered video, along with subsequently recorded video for the duration of the alarm, into long-term video.

Another aspect of the invention involves medium-term video recording. This is when, for predetermined periods during the day, all or pre-selected CCTV installations 140a-f are activated to record data in a medium-term data storage device, either locally or remote depending on the application. This video data is maintained for a limited period of time before being overwritten, such as one day, one week or, most preferably, one month. Examples of predetermined periods include break-times and lunch-times in schools, where children are not in the classroom under close supervision.

Also, although not shown, the invention finds another use when combined with a master alarm, or high-level alarm, separate from the lone worker alarm unit 10. Here, the master alarm activates the whole CCTV sub-system to record continuously, and raises a high-level alarm via the alarm notification units 118, 214, and causes the system 1 to save all buffered video. The master alarm may be activated by one or more dedicated switch units in the building 100 or remote monitoring site 200, or by a fire alarm or a burglar alarm. In this way, if a serious incident occurs, such as the entry of a dangerous intruder or a fire, video evidence can be captured and preserved as evidence, without impacting on privacy.

Also, although not shown, the invention finds another use when combined with an intermediate alarm activator button located on the lone worker alarm unit 10. Here, the intermediate alarm activation button transmits a video recording request signal which activates selected CCTV installations 140a-f depending on the last known location of the lone worker alarm unit. The selected CCTV installations 140a-f are based on the last known location and also based on adjacent zones, where appropriate, to take account of accidental or inaccurate readings from the RFID interrogators 130a-f. In this situation, an alarm is not raised but video is permanently recorded. This is useful where the lone worker feels threatened but is unsure of the severity of the problem and does not wish to call for assistance.

Fig. 7 is a flowchart showing a method for detecting the location of a lone worker alarm unit 10 within a building according to the first and second embodiments of the invention.

At step S700, each RFID interrogator 130a-f monitors to see whether an RFID signal is detected from a nearby RFID tag.

At step S710 if a signal is not detected, then step S700 is repeated. If a signal is received then the unique ID code of the detected RFID tag is sent to the receiving station 115 of the control room 114 at step S720.

Then, at step S730, the location of the lone worker alarm unit 10 is recorded in the database 117.

Of course, when a remote monitoring station 200 is present in the system 1, then the unique ID is relayed to the remote monitoring station 200 via the receiving station 115, and that information is recorded in the database 206 located in the remote monitoring station 200, in addition to, or in place of the database 117.

Fig. 8 is a flowchart showing a method of activating an alarm according to the first and second embodiments of the invention.

At step S800, the system 1 monitors for an alarm signal received from the lone worker alarm unit 10, in this example over the GSM telecommunications network 50.

At step S810 if an alarm signal is not received, then step S800 is repeated. If an alarm signal is received, then the last known location, or zone, of the lone worker alarm unit 10 is determined from the database 117 or 206 at step S820.

At step S830, an alarm is activated which causes the alarm notification unit 118 and/or 214 to output the zone identifier of the last-known location of the lone worker alarm unit 10.

Then, at step S840, the alarm is reset by a user and the method repeats from step S700.

Fig. 9 is a flowchart showing an alarm activation method according to the second embodiment of the invention.

Here, at step S900, an alarm is received at the remote monitoring station 200 via the GSM telecommunications network 50.

Then, at step S910, the zone corresponding to the last-known location of the lone worker alarm unit 10 is determined from the database 206, based on the time stamp information.

Step S920, an alarm is output together with the last-known location.

Then, step S930 the CCTV installation 140a-f is activated in the zone corresponding to the last-known location. If necessary depending on the application, then neighbouring CCTV installations are also activated. Additionally, the CCTV installations 140b at the entry/exit points 112 of the building 100 are also activated if not already activated.

By activated, it is meant that each camera 152 of the corresponding CCTV installation 140a-f, 150 is instructed to transmit video data back to a digital video recorder, in this case the digital video recorder 208 located in the remote monitoring station 200, via the receiving CCTV hub 159, communications server 119 and 3G telecommunication network 60.

At step S940, any buffered video relating to the activated CCTV installations is also sent to the digital video recorder 208, or made permanent locally.

At step S950, live video is displayed via the TV display panel 210 and the remote monitoring station 200. Also, in case of any doubt, the digital video recorder 208 is arranged to record video data from the moment the alarm signal was received and an alarm was raised.

At step S960, an optional voice channel is opened between the remote monitoring station 200, and one of the activated CCTV installations 140a-f. This is achieved using the microphone 212 at the remote monitoring station 200.

Finally, step S970, the alarm is eventually reset and the method repeats from step S900.

Although not shown, it is envisaged that the system could switch over to the use of GPS based systems once the lone worker leaves the building 100. This could be achieved by monitoring relative signal strengths of GPS versus RFID in the lone worker alarm unit 10, in combination with signals from RFID interrogators 130b at the entry/exit points 112.

Also, one or more lone worker alarm units 10 may be static and associated with a particular zone, such as dedicated classroom alarm units 10. The system 1 would be modified accordingly, as there would be no need to monitor the location of such static lone worker alarm units 10.

While the invention has been described in relation to a school, many other applications are envisaged. For example, the system 1 could be employed in a hospital, public library, government building, factory, office building, university campus, and so on.

Also, the CCTV sub-system may be wholly arranged in the control room 114, without communication with the remote monitoring station 200. In this case, or in any case, an output device such as a video monitor or bank of video monitors may be provided in the control room 114, SO that a local response can be initiated with the above-mentioned accuracy.

The skilled person would realise that any form video recording may be employed, for example by using memory, digital video recorders, or networked video recorders. There could be any means of fixed or removeable storage located at any suitable point in the building 100 or system 1 for recording video.

Although some example methods of communication between items in the system have been described, such as GSM and 3G, the invention may be realised by any form of communication, including those yet to be developed.

Although a few preferred embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAIMS1. A lone worker alarm system comprising: a network of at least two RFID interrogator devices located within a building; a lone worker alarm unit comprising an alarm activator configured to send an alarm signal when activated; and an RFID tag arranged to communicate with the network so that the lone worker alarm system has a record of the last known location of the lone worker alarm unit; wherein the system is configured to receive the alarm signal and to discover and output the last known location of the lone worker alarm unit.
2. The lone worker alarm system of claim 1, wherein the lone worker alarm unit is arranged to send the alarm signal over a wireless link.
3. The lone worker alarm system of claim 1 or claim 2, wherein the lone worker alarm unit is arranged to send the alarm signal over a telecommunications network.
4. The lone worker alarm system of claim 3, wherein the telecommunications network is one of a GSM or 3G telecommunications network.
5. The lone worker alarm system of any preceding claim, wherein the last known location is determined based on a time stamp recording the time the RFID tag last communicated with one of the RFID interrogator devices, and location information of the RFID interrogator device which last communicated with the RFID tag.
6. The lone worker alarm system of any preceding claim, wherein the lone worker alarm system comprises a database arranged to store information relating to the position of each RFID interrogator within the building, and to store information relating to the time each RFID interrogator communicates with the RFID tag so that the last known location of the lone worker alarm unit can be discovered.
7. The lone worker alarm system of claim 6, wherein the database is located in the building.
8. The lone worker alarm system of any preceding claim, wherein the lone worker alarm system comprises a receiving station arranged to communicate with each RFID interrogator.
9. The lone worker alarm system of claim 8, wherein the receiving station is arranged to communicate wirelessly with each RFID interrogator.
10. The lone worker alarm system of claim 8 or claim 9, wherein the receiving station is arranged to receive the alarm signal.
11. The lone worker alarm system of any of claims 8, 9 or 10, wherein the receiving station is located in the building.
12. The lone worker alarm system of claim 10 or claim 11, wherein the lone worker alarm system comprises an alarm notification unit arranged to output the last known location of the lone worker alarm unit when the alarm signal is received by the receiving station.
13. The lone worker alarm system of claim 12, wherein the alarm notification unit is located in the building.
14. The lone worker alarm system of any preceding claim, wherein the system comprises a CCTV sub-system comprising a network of CCTV installations.
15. The lone worker alarm system of claim 14, wherein the network of CCTV installations corresponds to the network of RFID interrogators, so that at least one CCTV installation is provided for each RFID interrogator.
16. The lone worker alarm system of claim 13 or claim 14, wherein each CCTV installation includes at least one camera, a microphone, a loudspeaker and a communications unit arranged to transmit data and receive data.
17. The lone worker alarm system of any of claims 14 to 16, wherein video is only recorded by at least one CCTV installation into long-term memory at the point at which the alarm signal is received in order to protect the privacy of the occupants of the building.
18. The lone worker alarm system of any of claims 14 to 17, wherein the CCTV sub-system is arranged to buffer video from each CCTV installation for a predetermined overwrite period when no alarm signal has been generated.
19. The lone worker alarm system of claim 18, wherein the overwrite period is between around 1 minute and 10 minutes.
20. The lone worker alarm system of claim 19, wherein the overwrite period is 10 minutes.
21. The lone worker alarm system of any of claims 18 to 20, wherein the video is buffered in a memory local to each CCTV installation.
22. The lone worker alarm system of any of claims 18 to 20, wherein the video is buffered in a memory external from each CCTV installation.
23. The lone worker alarm system of any preceding claim, wherein the lone worker alarm system comprises a remote monitoring centre.
24. The lone worker alarm system of any of claims 14 to 23, wherein the lone worker alarm system is arranged to record data from one or more selected CCTV installations when the alarm signal is generated.
25. The lone worker alarm system of claim 24, wherein each selected CCTV installation is arranged to transmit video to a digital video recorder when the alarm signal is generated.
26. The lone worker alarm system of claim 25, wherein the system is arranged to send buffered data from the one or more selected CCTV installations to the digital video recorder when the alarm signal is generated.
27. The lone worker alarm system of any of claims 24 to 26, wherein the lone worker alarm system is arranged to select the CCTV installation associated with the last known location of the lone worker alarm unit.
28. The lone worker alarm system of any of claims 24 to 27, wherein one or more neighbouring CCTV installations are also selected when the alarm signal is generated.
29. The lone worker alarm system of any of claims 25 to 28, wherein the digital video recorder is located in the building.
30. The lone worker alarm system of any of claims 25 to 28, wherein the digital video recorder is located remote from the building at the remote monitoring centre.
31. The lone worker alarm system of any of claims 25 to 28, wherein there are two digital video recorders, one located in the building, and one located in the remote monitoring centre.
32. The lone worker alarm system of any of claims 25 to 31, wherein the lone worker alarm system is arranged to relay video being recorded to an output screen in the remote monitoring centre.
33. The lone worker alarm system of any of claims 24 to 32, wherein the lone worker alarm system is arranged to de-select certain CCTV installations after the alarm signal has been received so that only video pertinent to the alarm is recorded.
34. The lone worker alarm system of any of claims 24 to 33, wherein the lone worker alarm system is arranged to record, long-term, video from all, or selected, CCTV installations during pre-selected time periods.
35. The lone worker alarm system of any of claims 24 to 34, wherein the lone worker alarm system is configured to record video from specific pre-selected high risk locations even when an alarm is not raised.
36. The lone worker alarm system of claim 35, wherein the recorded video is automatically overwritten a predetermined time after recording.
37. The lone worker alarm system of claim 36, wherein the predetermined time is between I day and 3 months.
38. The lone worker alarm system of claim 37, wherein the predetermined time is 1 month.
39. The lone worker alarm system of any of claims 24 to 38, wherein the lone worker alarm system is arranged to record video from all CCTV installations, and to record all buffered video, when a high-level alarm is raised.
40. The lone worker alarm system of claim 39, wherein the high-level alarm is caused by a panic button, or master button.
41. The lone worker alarm system of claim 40, wherein the panic button, or master button, can be activated from the building.
42. The lone worker alarm system of claim 40 or claim 41, wherein the or a panic button or master button can be activated from the remote monitoring centre.
43. The lone worker alarm system of any of claims 39 to 42, wherein the high-level alarm is raised by a fire alarm or a burglar alarm in the building.
44. The lone worker alarm system of any of claims 24 to 43, wherein the lone worker alarm unit comprises an intermediate alarm activator configured to send a video recording request signal when activated, which causes the system to record video from selected CCTV installations depending on the location of the lone worker alarm unit, but which does not raise an alarm.
45. A method of locating a lone worker, the method comprising: monitoring a lone worker alarm unit having an RFID tag using a network of RFID interrogators spread throughout a building and recording the last known location of the lone sending an alarm signal from the lone worker unit; and upon receiving the alarm signal, discovering and outputting the last known location of the lone worker alarm unit.
46. A lone worker alarm unit comprising: an RFID tag for communication with a network of RFID interrogators located within a building; an alarm activation button for sending an alarm signal; and an alarm notification unit for sending the alarm signal to an alarm monitoring apparatus.
47. The lone worker alarm system of claim 46, wherein the alarm notification unit is arranged to transmit the alarm signal wirelessly.
48. The lone worker alarm system of claim 47, wherein the alarm notification unit is arranged to transmit the alarm signal wirelessly over a telecommunications network.
49. The lone worker alarm system of claim 48, wherein the alarm notification unit is arranged to transmit the alarm signal wirelessly over a GSM or 3G telecommunications network.
50. The lone worker alarm system of any of claims 46 to 49, wherein the lone worker alarm unit comprises an intermediate alarm activator configured to send a video recording request signal when activated, which causes the system to record video from selected CCTV installations depending on the location of the lone worker alarm unit, but which does not raise an alarm.