GB2568318A

GB2568318A - Tracking device, system and method

Info

Publication number: GB2568318A
Application number: GB1718825.1A
Authority: GB
Inventors: Marinelli Claudio; Sele Christoph; Wright Guy
Original assignee: EIGHT19 Ltd
Current assignee: EIGHT19 Ltd
Priority date: 2017-11-14
Filing date: 2017-11-14
Publication date: 2019-05-15
Also published as: GB201718825D0; WO2019097223A1

Abstract

Tracking an entity in a network comprising a set of devices, comprising, switching a device for tracking the entity into a first operation mode if the device is determined to be in motion or was recently in motion and has now become stationary and communicating with the set of devices operationally connected to the device to determine a location of the device within the network and switching the device into a second operation mode if the device is determined to be stationary and a location of the device within the network has been determined to a specified degree of accuracy. The device comprises a sensor which comprises one or more of an accelerometer, a gyroscope, a gyrometer, a compass, a barometer and a magnetometer. The communication module comprises a radio communication system for communication with the set of devices operationally connected to the device.

Description

TRACKING DEVICE, SYSTEM AND METHOD

FIELD OF THE INVENTION

The present invention generally relates to a device for tracking an entity in a network and methods and systems fortracking entities in a network.

BACKGROUND TO THE INVENTION

It is desirable to be able to track the location of assets within an environment so that it is possible to readily find an asset when required and/or to ensure that access to an asset is restricted to authorised parties. For example, it is desirable to track medical (patient) records and medical equipment within a hospital, so that the records and equipment can be obtained quickly when needed.

The present applicant has recognised the need for improved techniques to track assets.

SUMMARY

In a first aspect of the invention there is provided a device for tracking an entity in a network comprising a set of devices, the device comprising: at least one processor; a communication module; at least one power source; and a unique identifier identifying the device; wherein the at least one processor and communication module are configured to: switch the device into a first operation mode if the device is determined to be in motion or was recently in motion and has now become stationary, and communicate with the set of devices operationally connected to the device to determine a location of the device within the network; and switch the device into a second operation mode if the device is determined to be stationary and a location of the device within the network has been determined to a specified degree of accuracy.

In a second aspect of the invention there is provided a system for tracking entities in a network, the system comprising: a plurality of devices of the type described herein; at least one reader device configured to communicate with the plurality of devices to record the location and status of each device; and at least one server configured to communicate with each reader device to obtain and store the location and status of each device.

In a third aspect of the invention there is provided a method for tracking an entity in a network using a tracking device coupled to the entity, the method of the tracking device comprising: processing data to determine if the tracking device is in motion; and switching the device into a first operation mode if the tracking device is determined to be in motion or was recently in motion and has now become stationary, and communicate with a set of devices operationally connected to the tracking device to determine a location of the tracking device within the network; or switching the tracking device into a second operation mode if, responsive to processing the data, the tracking device is determined to be stationary and a location of the device within the network has been determined to a specified degree of accuracy.

In a related aspect of the invention there is provided a non-transitory data carrier carrying code which, when implemented on a processor, causes the processor to carry out any of the methods described herein.

Computer program code for carrying out operations of the present techniques may be written in any combination of one or more programming languages, including object oriented programming languages and conventional procedural programming languages. Code components may be embodied as procedures, methods or the like, and may comprise sub-components which may take the form of instructions or sequences of instructions at any of the levels of abstraction, from the direct machine instructions of a native instruction set to high-level compiled or interpreted language constructs.

The techniques further provide processor control code to implement the above-described methods, for example on a general purpose computer system or on a digital signal processor (DSP). The techniques also provide a carrier carrying processor control code to, when running, implement any of the above methods, in particular on a non-transitory data carrier - such as a disk, microprocessor, CDor DVD-ROM, programmed memory such as read-only memory (firmware), or on a data carrier such as an optical or electrical signal carrier. The code may be provided on a carrier such as a disk, a microprocessor, CD- or DVD-ROM, programmed memory such as non-volatile memory (e.g. Flash) or read-only memory (firmware). Code (and/or data) to implement embodiments of the techniques may comprise source, object or executable code in a conventional programming language (interpreted or compiled) such as C, or assembly code, code for setting up or controlling an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array), or code for a hardware description language such as Verilog™ or VHDL (Very high speed integrated circuit Hardware Description Language). As the skilled person will appreciate, such code and/or data may be distributed between a plurality of coupled components in communication with one another. The techniques may comprise a controller which includes a microprocessor, working memory and program memory coupled to one or more of the components of the system.

It will also be clear to one of skill in the art that all or part of a logical method according to the preferred embodiments of the present techniques may suitably be embodied in a logic apparatus comprising logic elements to perform the steps of the above-described methods, and that such logic elements may comprise components such as logic gates in, for example a programmable logic array or application-specific integrated circuit. Such a logic arrangement may further be embodied in enabling elements for temporarily or permanently establishing logic structures in such an array or circuit using, for example, a virtual hardware descriptor language, which may be stored and transmitted using fixed or transmittable carrier media.

In an embodiment, the present techniques may be realised in the form of a data carrier having functional data thereon, said functional data comprising functional computer data structures to, when loaded into a computer system or network and operated upon thereby, enable said computer system to perform all the steps of the above-described method.

BRIEF DESCRIPTION OF THE DRAWINGS

The techniques are diagrammatically illustrated, by way of example, in the accompanying drawings, in which:

Figure 1 shows a block diagram of an example tracking device;

Figure 2 shows a schematic diagram of a system for tracking entities;

Figure 3 shows a specific implementation of a system for tracking entities;

Figure 4 shows different example ways that a tracking entity may be used; and

Figure 5 shows a flow diagram of example steps performed by a tracking device.

DETAILED DESCRIPTION

Broadly speaking, the present techniques relate to an apparatus, a system and a method for tracking entities in an environment. For example, particular embodiments of the present techniques provide a system for tracking medical assets (e.g. medical records, medical equipment, medicines, etc.), medical personnel, and patients within, or relative to, a particular environment (such as a hospital). It will be understood that the tracking device, system and methods described herein may be implemented in any environment, and the hospital environment mentioned herein is merely one illustrative example.

Figure 1 shows a block diagram of an example tracking device 100. The tracking device 100 comprises at least one processor 102. The at least one processor 102 may be a microcontroller or microprocessor. The or each processor 102 may be coupled to at least one memory (not shown). The memory may comprise working memory, and program memory storing computer program code to implement all or part of tracking methods described herein. The memory may store, among other things, an identifier 108 which uniquely identifies the tracking device 100. The memory may comprise a volatile memory such as a random access memory (RAM), for use as temporary memory whilst the processor 102 is processing data or performing tasks in relation to tracking. Additionally or alternatively, the memory may comprise non-volatile memory such as Flash, read only memory (ROM) or electrically erasable programmable ROM (EEPROM), for storing data, programs, or instructions received or processed by the processor 102.

The tracking device 100 comprises a communication module 104 for communicating with other devices within a network. For example, the tracking device may be able to communicate with other tracking devices, reader devices (i.e. devices which are able to read data of the tracking devices), servers, and potentially user devices. As the tracking device 100 is for tracking the movement of/location of entities within an environment, the tracking device 100 preferably uses wireless communication techniques to communicate. Accordingly, the communication module 104 may use wireless communication (e.g. WiFi), short range communication such as radio frequency communication (RFID) or near-field communication (NFC), or by using the communication protocols specified by e.g. ZigBee, Thread, Bluetooth (RTM), Bluetooth Low Energy (RTM), IPv6 over Low Power Wireless Standard (6L0WPAN) or Constrained Application Protocol (CoAP), cellular/mobile communication (e.g. GSM, GPRS, 2G, 3G, 4G, 5G, etc.), or any other wireless communication protocol to transmit location data.

The tracking device 100 comprises at least one power source 106. In embodiments, the tracking device 100 may comprise at least one or more of any of the following types of power source: a battery, a cell, a capacitor, a super capacitor, a rechargeable battery, a non-rechargeable battery, and a light-energy powered battery. The battery may be chargeable by connection to a mains power supply. In embodiments, the battery may be chargeable by connection to a lightenergy harvesting module, such as a solar cell 114. The battery may have a finite lifetime, after which the tracking device 100 is no longer functional (or is not as reliable). In such embodiments, the tracking device 100 may be returned to the supplier/manufacturer, in exchange for a replacement tracking device 100.

The tracking device 100 may comprise at least one sensor 110. The sensor 110 may be or comprise a motion sensor/motion detector or accelerometer, which may be used to determine when the tracking device 100 is stationary and when it is in motion. The sensor 110 may be or comprise a sensor for determining/measuring the orientation of the tracking device 100. For example, the sensor 110 may be or may comprise any of: a compass, a gyroscope, a gyrometer, a barometer, a magnetometer, and an accelerometer.

The tracking device 100 is couplable to entities that are to be tracked within an environment. For example, the tracking device 100 may be couplable to a piece of medical equipment which is to be tracked within a hospital. Thus, the tracking device 100 may comprise at least one coupling mechanism or attachment means to removably couple the tracking device 100 to the entity to be tracked. Preferably, the tracking device 100 is readily removable from the entity to which it is attached/coupled, to enable charging of the power source 106 of the tracking device, or maintenance or replacement, for example.

The tracking device 100 may comprise a user interface 116, such as a conventional display screen, one or more lights which may be used to indicate a status and/or operation mode of the tracking device 100, and/or interfaces that enable a user or operator of the tracking device 100 to input instructions. For example, the tracking device 100 may comprise one or more buttons which a user of the device may use to change a state of the tracking device.

Thus, the tracking device 100 of the present invention provides an infrastructure-free location tracking mechanism, which uses a wireless communication technology (such as, but not limited to, Bluetooth low energy (RTM)) to communicate with other devices and apparatuses, to provide real-time location and status information of the tracking device (and thereby, of the entity to which it is attached). The tracking device may, in embodiments, use a motion sensor and signal processing to detect movement of the tracking device.

The tracking device 100 may be switchable between at least two operation modes: a first operation mode in which the tracking device 100 is in motion and in which the tracking device uses the location of other fixed/stationary devices to determine its location, and a second operation mode in which the tracking device 100 is stationary. When the tracking device is in the second operation mode, it may not need to transmit location data as frequently as when the tracking device

100 is in motion. Furthermore, in the second operation mode, the tracking device 100 may be used by other devices to determine their location.

Thus, the operation mode of the tracking device 100 may change depending on whether the tracking device is mobile or stationary. When the tracking device is mobile, it may be possible to determine the location of the tracking device through triangulation using other stationary devices. When the tracking device is stationary, it may be used for location triangulation of other tracking devices.

Transition from one operation mode to another operation mode may be gradual, in embodiments. For example, if a tracking device 100 is determined to be stationary, (for example using accelerometer data or consistent signal strength from a significant number of other tracking devices), the tracking device may initially remain in the mobile (first) operation mode until an approximate location of the tracking device has been determined. Over a period of time, tracking device location may be predicted with ever-increasing accuracy by reading radio signal strength reports from other tracking devices that are in the stationary (second) operation mode. As this accuracy reaches a maximum, the tracking device may be considered to be in the stationary (second) operation mode. In the stationary operation mode, the tracking device 100 may contribute to determining the location of other tracking devices within range, based on radio signal strength reports derived from communications with those other devices. The tracking device 100 may contribute in a similar way during its transition from mobile to stationary mode, but with correspondingly reduced weighting in the statistical triangulation algorithm reflecting the location uncertainty.

Signal strength data from a statistically significant number of other devices may contribute to usefully determining the location of a tracking device even if the location of those devices themselves has not been accurately determined.

Accordingly, in embodiments there is provided a device for tracking an entity in a network comprising a set of devices, the device comprising: at least one processor; a communication module; a power source; and a unique identifier identifying the device; wherein the at least one processor and communication module are configured to: switch the device into a first operation mode if the device is determined to be in motion or was recently in motion and has now become stationary, and communicate with the set of devices operationally connected to the device to determine a location of the device within the network; and switch the device into a second operation mode if the device is determined to be stationary and a location of the device within the network has been determined to a specified degree of accuracy. Here the term recently in motion may mean that the device was in motion any time within the last few seconds, the last few minutes, the last hour, the last few hours, etc. These are non-limiting example time periods - the specific time period may depend on the environment in which the device is used. The term specified degree of accuracy may mean that the device location has been determined to within a few metres or has been determined to be stable/fixed for a particular amount of time, for example.

In embodiments, if the device is determined to have been recently in motion, the at least one processor and the communication module may be configured to gradually switch the device from the first operation mode into the second operation mode by: determining an approximate location of the device; improving, over a defined period of time, an accuracy of the approximate location of the device using signals received by the device from the set of devices operationally connected to the device; and switching the device into the second operation mode when the accuracy of the location of the device is within the specified degree of accuracy.

Preferably, when the device gradually transitions between the first operation mode and the second operation mode, the at least one processor and communication module may be configured to: communicate with at least one device of the set of devices operationally connected to the device to enable determination of a location of the at least one device within the network, and transmit data indicating the accuracy of the device location to the at least one device to enable the at least one device to weight any communications from the device. Thus, while the device 100 is transitioning from the first operation mode to the second operation mode, the device 100 may still be able to participate in communications that help other devices to determine their locations within the network. However, the device 100 provides additional information to the other devices to ensure that any communications or signals received from the device

100 are weighted depending on the accuracy of the determined location of device 100. That is, the closer the device 100 is to switching into the second operation state, the more accurately its location is known/determined, and therefore, the more weight can be placed on the signals received from the device 100 by other devices trying to determine their location.

The tracking device 100 may comprise a radio antenna 112, or similar mechanism to enable communication via radio. Tracking devices that use radio communication signal strength to determine proximity to other devices commonly use radio transmission in one direction only. For a given distance and environment, the reported signal strength can still vary widely over time and between devices. This is in part due to parameter variation within the device hardware. Embodiments of the present invention may mitigate against this element of variation by reading the received signal strength report of a transmission in both directions, i.e. a signal transmitted from device A and measured by device B, and additionally a signal transmitted by device B, and measured by device A.

Radio antennas generally do not radiate with equal power in all directions, with some directions in 3-dimensional space having particularly bad 'nulls'. In embodiments where the tracking device 100 comprises an accelerometer (and/or a gyroscope or compass), it may be possible to determine the direction of gravity and thus, the orientation of the antenna in a single spatial plane. This information can be used to increase the certainty in ranging other devices in the vicinity of the tracking device 100.

An integrated accelerometer may be used to determine whether the tracking device (and therefore, the entity to which the tracking device 100 is attached) is in motion or is stationary. A tracking device that has been stationary for a period of time may save power by reducing the rate at which it takes part in networking and reporting activity. Additionally, by reporting the time since a tracking device was last used over the network, it may be deduced whether a tracking device can be considered 'in use' or whether the tracking device is being stored, for example.

In embodiments, when the device 100 is in the second operation mode, the at least one processor 102 and communication module 104 may be configured to: communicate with at least one device of the set of devices operationally connected to the device 100 to enable determination of a location of the at least one device within the network.

In embodiments, the at least one processor and the communication module may be configured to: analyse signals received from a plurality of devices operationally connected to the device to determine if a signal strength of each signal is steady or fluctuating; and determine if the device is in motion or is stationary.

In embodiments, the device 100 may comprise at least one sensor 110; wherein the at least one processor and the communication module are configured to use data from the at least one sensor to determine if the device is in motion or is stationary. In embodiments, the at least one sensor may comprise an accelerometer and/or a motion sensor.

In embodiments, the communication module 104 may use a wireless communication protocol to communicate with the set of devices operationally connected to the device.

In embodiments, the communication module 104 may use Bluetooth (RTM) or Bluetooth Low Energy (RTM) to communicate with the set of devices operationally connected to the device.

In embodiments, the communication module 104 may comprise a radio communication system for communication with the set of devices operationally connected to the device.

In embodiments, if the device is in the second operation mode, the at least one processor and communication module may be configured to: reduce a rate at which the device communicates with the set of devices operationally connected to the device to reduce power consumption of the device.

In embodiments, the device 100 may comprise at least one light energy harvesting module coupled to the power source 106 and arranged to recharge the power source (e.g. battery). The light energy harvesting module may comprise at least one photovoltaic cell 114. The at least one energy harvesting module may be configured to harvest energy from one or both of: ambient light, and sunlight. In embodiments, the solar cell /photovoltaic cell 114 may be provided within the external casing of the device, to enable the device 100 keep its internal power source 106 charged for longer.

In embodiments, the device 100 may comprise a user interface 116.

The user interface 116 may be configured to indicate a low power warning to a user when the at least one power source reports that a power level of the power source 106 is below a predetermined level.

The user interface 116 may comprise at least one button to set an operation mode or status of the device 100.

In embodiments, the device 100 may comprise a tamper-proof alarm 118 configured to emit a sound if the tampering is detected and/or to send a message to a remote server or remote device if the tampering is detected.

In embodiments, the device 100 may comprise attachment means for coupling the device to an entity to be tracked.

In embodiments, the at least one processor and the communication module may be configured to: transmit messages to at least one reader device, each message comprising the unique identifier of the device, a current location of the device, and a status or operation mode of the device.

In embodiments, the tracking device 100 may be provided in multiple different sizes. A larger size tracking device may be suitable for an entity which is larger, or which is to be tracked for a longer time (as a larger tracking device may have more batteries/a longer battery life).

In embodiments, a reader device may be used for calibration or data collection in areas/environments with a small number of tracking devices. The reader device may be mobile and may be moved around by a user through an environment to gather location and status data of each tracking device. This may be useful for environments with small numbers of tracking devices because with only a few tracking devices, it may not be possible to accurately determine location via triangulation. Thus, the mobile reader device may be used regularly within an environment to verify location of each tracking device. The reader device (also referred to herein as an audit device) may be a hand-held or trolley-mounted device. The audit device may be moved through the hospital environment, e.g. on a daily basis, as part of standard routines. The audit device may record the status of each tracking device 100, as well as the location of the device 100 to within approximately 5m, for example. The data collected by the audit device may be uploaded to a remote server and added to a report for users or third parties, which provides the location and status of all tracking devices (and tracked entities) within the hospital.

In embodiments, an environment may comprise one or more 'bridge' or gateway devices to connect the network of tracking devices 100 to a conventional LAN/WAN. This may improve the ability to track and accuracy of tracking a tracking device automatically and in real-time. The portable audit device described above may then be used only for initial set-up of the system/network, and/or for infrequent 're-calibration' on sites containing a small number of tracking devices. Coupling the tracking devices 100 to a LAN/WAN may reduce battery life by up to 50%, but may still provide a service life of over a year when the tracking device is a large device. It may be possible, in embodiments, to integrate physically larger tracking devices that are fitted to larger equipment into the ecosystem, and to rely on these larger devices for real-time location tracking of other smaller tracking devices. This may increase battery/service life of smaller tracking devices.

In embodiments, an environment may be provided with 'geo-fencing' to determine when a tracking device enters and/or leaves the environment. For example, the exit/entrance to an environment may be provided with a specific type of reader device which can determine when a tracking device has passed in to or out of the environment. The reader device may be able to sound an alarm if a tracking device has passed out of the environment when it should not have. For example, it may be desirable for pieces of medical equipment or patient files to remain within a hospital. If these entities are determined to pass out of the environment, an alarm may sound to indicate possible theft or a security breach.

In embodiments, as the tracking device 100 may use industry-standard radio communication technology, it is possible that the tracking device may also easily communicate with a personal electronic device carried by individuals (e.g. hospital personnel). Using this communications capability, and a software application running on that personal device, tracked entities could be 'checked out' and assigned to individual personnel (e.g. a doctor or nurse), or their clients (e.g. patients). The reporting mechanism could then include information on who has been using the tracked entity, and for how long.

In embodiments, the tracking device 100 may be capable of ambient (or solar) light energy harvesting for energy-autonomy.

In embodiments a low battery signal may trigger recharging of a battery, or battery replacement, or tracking device 100 replacement.

In embodiments, the tracking device 100 may be placed into a low-power state depending on the location of the tracking device. For example, particular locations within an environment may be classified as 'offline' locations (e.g. an equipment store). In such locations, the tracking device 100 may be undergoing maintenance or may be 'out-of-service', and thus, it may not be required for the device 100 to transmit updates as frequently. Accordingly, the tracking device 100 may conserve power by switching into a low-power state in such locations. The tracking device 100 may automatically switch into this low-power state, or a user may switch the state manually via the user interface 116 (e.g. a button). The tracking device 100 may be automatically or manually re-activated (i.e. switched out of the low-power state) when the tracking device is in motion. If the tracking device 100 comprises an accelerometer or motion sensor, the tracking device 100 may be automatically able to detect motion and switch out of the low power state. Switching into a low-power state may help to increase the lifetime of the battery and therefore, the service lifetime of the device 100.

In embodiments, switching a state of the tracking device may comprise switching the tracking device into a low-power state when the tracking device is determined to be in a location where real-time location tracking is not required. The tracking device may be switched into an online state when the tracking device is determined to no longer be in this location.

If a tracking device 100 is determined to be in a particular location where real-time tracking is not required (a store room, for example), the tracking device 100 may be able to switch into a very low power sleep mode to conserve battery life. This mode differs from the normal operating mode in that it partakes in radio communication far less frequently.

The tracking device may be switched into different states such as an in-use state, an offline state, a low-power state, and a maintenance-required state. A user may be able to switch the tracking device 100 into a particular state via the user interface, e.g. via a push button. The button may be pressed to flag that the entity to which the tracking device 100 is attached is 'in use'. This flag may timeout or expire after a specified amount of time (e.g. after 24 hours). The status of this flag is collected during each audit, and included in the audit report. In this way, it is possible to differentiate between a tracking device/an entity that is in active use, and a tracking device/an entity that is idle and free for use elsewhere. This same data may be collated into a periodic report (e.g. bi-annually) to give an indication of equipment utilisation. In embodiments, the button may be pressed to flag that the tracking device 100 is in need of maintenance. This information would then be reported to the relevant department/party.

A tracking beacon button can be pressed to flag that the attached equipment is 'in use'. This flag can time out after 24 hours (for example). The status of this flag is collected during each audit, and included in the audit report. In this way, it is possible to differentiate between equipment that is in active use, and equipment that is stood idle and free for use elsewhere. This same data can be collated into a periodic report (e.g. bi-annually) to give a good indication of equipment utilisation.

In embodiments, it may be possible for a tracking device 100 to be assigned to a particular person, e.g. a member of staff or a patient, and it may be possible to link or couple the tracking device 100 to a user device of that person, or to a further tracking device. If hospital staff are individually equipped with any kind of PDA or similar personal electronic device, it may be possible for them to use a software application on that device to 'check out' an item of equipment (and tracking device) to themselves, and add any other relevant metadata. The PDA may be briefly held in proximity to the tracking device to register this metadata to that particular item of equipment. If desired, the staff member could then additionally assign the equipment to a specific patient, in embodiments.

Tracking of rapidly moving items or persons (e.g. patients), may require using a higher time resolution on the tracking device 100. The time resolution of the tracking devices may be increased to track items that are moving rapidly and frequently, such as patients. This feature may be used in conjunction with the real-time location tracking and auditing techniques described above.

In embodiments, the tracking device 100 comprises a tamper-proof system. The tamper-proof system may comprise an alarm which emits a sound or sends a signal to a remote device/server when the tracking device 100 is tampered with (e.g. is opened or removed from a particular environment).

In embodiments, the tracking device 100 may comprise communication means for long-range communication, e.g. to enable tracking outside of a hospital building (via long range wireless technology).

In embodiments, the tracking device 100 is small, portable and relatively lightweight, to enable it to be readily affixed to entities such as medical equipment, patient records, individuals, and medicines. For example, the area of the hardware of the tracking device 100 may be smaller than the area of a UK postage stamp, and may have a thickness of e.g. 3mm. the overall size of the tracking device 100 may be larger due to the battery/power source 106 and the casing that encases the hardware and battery. We then need to add casework and a battery. The overall device size may be adjustable to provide the required balance between size and battery life to suit particular needs.

In particular embodiments, the battery life may be directly related to the overall size of the tracking device 100. For example, a tracking device that has a diameter or width of 36mm and a depth/thickness of 5mm may provide a service life of between six months to one year. A similar device with a depth approaching 10mm may provide a service life of several years. Thus, the tracking device 100 may be fabricated to suit the end use of the device. In embodiments, each tracking device 100 may routinely report battery status (e.g. remaining power or remaining battery life) as part of its location report.

Thus, in embodiments, the at least one processor and the communication module may be configured to: report to an external server when the device is nearing the end of its lifetime. When a device reports that it is nearing the end of its service (battery) lifetime, this information is reported back to the device supplier/manufacturer, and a replacement device is automatically shipped to the user. The replacement device may be pre-configured to clone the existing tracking device, so that no further set-up or configuration is required by the user. The returned tracking device may be recycled by recharging or replacing the internal battery, for example.

In embodiments, the device 100 may comprise an external casing for protecting the device. The external casing may provide a hermetic seal around the device. The external casing may be formed of an antibacterial (or antimicrobial) polymer or plastics material, which may be easy to clean. The external casing may be injection-moulded into any suitable shape.

Turning to Figure 2, this shows a schematic diagram of a system 200 for tracking entities in, or relative to, an environment. The system 200 comprises a plurality of tracking devices 100 and a plurality of reader devices 202. (The number of devices illustrated in Figure 2 is purely exemplary). As explained above, the tracking devices 100 may be able to communicate with each other to enable location tracking, as shown by the dashed arrows. Each tracking device 100 may be able to communicate with one or more reader devices 202 to feedback information on the status and location of the tracking device 100, as shown by the dot-dash arrows. The reader device 202 may be able to communicate with an extern al/re mote server 204, so as to provide real-time location information to a user/operator of system 200, to a third party, or to a manufacturer/supplier of the tracking devices 100 (e.g. when a tracking device 100 is nearing the end of its service lifetime). The system 204 may transmit data to a database or data store 206.

Figure 3 shows a specific implementation of a system for tracking entities in a hospital environment. The hospital comprises a number of tracking devices 100. Each tracking device may be in the mobile (first) operation mode, or in the stationary (second) operation mode. Those tracking devices 100 which are mobile are indicated by the dashed boxes. Those tracking devices 100 which are stationary are indicated by the solid-line boxes.

As mentioned above, each tracking device 100 may be in one of a plurality of different states, e.g. available for use, in use and in service/in maintenance. The tracking devices 100 in Figure 3 which are available are indicated by the hash-filled boxes, while those that are in use are indicated by the dot-filled boxes, and those in service are the unfilled/unpatterned boxes.

The system comprises three reader devices: an audit device 202a, which is also mobile as explained above; a staff device 202b, which is mobile/portable; and an exit reader or gate device 302 to monitor the movement of tracking devices in to and out of the hospital environment. The tracking devices 100 may communicate with each other to e.g. determine their location - this triangulation communication is indicated by the double parallel lines between devices 100. The tracking devices 100 may communicate with each other to form a mesh network - these communications are indicated via the dotted lines between devices 100. The tracking devices may transmit status and location information to the reader devices and/or to a server 204 - this is indicated via the solid lines/arrows.

The environment shown in Figure 3 comprises multiple specified locations/areas: a ward, a library (i.e. where tracking devices 100 are stored for use), and a service/maintenance area. As explained above, a tracking device 100 may switch into a low-power state when the tracking device enters the service area.

The environment shown in Figure 3 comprises a server 204 for communicating with the devices 100/reader devices. The environment may also comprise a database 206 for storing location and status data, and may comprise means 304 for a third party to access information about the devices 100. The server 204 may provide this information to the means 304 directly, e.g. via an API, or the database 206 may provide this information to means 304 upon request. The means 304 may be a third party asset management software or system.

The exit reader 302 is located at an entrance/exit to the hospital to track movement of devices 100 in to and out of the hospital. As explained above, any unauthorised movement of a device 100 out of the hospital may cause an alarm to be raised.

As explained above, a tracking device 100 may be coupled to patients, or to medicines or equipment provided to a patient. Thus, tracking of entities may be possible outside of the environment as shown in Figure 3. To enable this, the tracking device 100 may comprise communication means for long-range communication, such as GSM, via a SIM card for example.

Figure 4 shows a number of different ways that the tracking device 100 may be used. In box (A), the tracking devices 100 are used to provide location information of the entities to which they are attached to audit device 202a. Optionally, the tracking devices 100 may provide device status information to the audit device 202a. In this case, the tracking devices 100 may only communicate with the audit device 202a, and not with each other. This means that location information can only be provided when the audit device 202a is passed through an environment, and is therefore, not real-time information. In box (B), the tracking devices 100 may be used to provide real-time location and status information, as the tracking devices 100 are able to communicate with each other as well as the audit device 202a. The audit device 202a may be used for calibration or re-verifying location information. In box (C), the tracking devices 100 may be able to link patients 306, medical staff 202b and tracked entities, such that real-time updates are provided to all.

Figure 5 shows a flow diagram of example steps performed by a tracking device. As mentioned above, the tracking device 100 processes data to determine whether the tracking device is in motion or is stationary. The tracking device 100 may use signals received from other devices (i.e. via the triangulation process described above) (step S502) to determine if the tracking device is in motion. In embodiments, the tracking device 100 may receive sensor data (step S500), e.g. from an accelerometer or motion sensor, which may help determine if the tracking device is in motion. At step S504, the tracking device analyses the signals (and optionally sensor data), to determine if the device is stationary. If the answer is no, i.e. the device is in motion, the device switches into the first operation mode (step S506). In this mode, the device communicates with other stationary tracking devices to determine its location (step S508). If the answer is yes, i.e. the device is stationary, the device switches into the second operation mode (step S510). In this mode, the device may communicate with one or more other devices to help those devices determine their location.

Embodiments of the present techniques also provide a non-transitory data carrier carrying code which, when implemented on a processor, causes the processor to carry out the methods described herein.

The techniques further provide processor control code to implement the above-described methods, for example on a general purpose computer system or on a digital signal processor (DSP). The techniques also provide a carrier carrying processor control code to, when running, implement any of the above methods, in particular on a non-transitory data carrier or on a non-transitory computerreadable medium such as a disk, microprocessor, CD- or DVD-ROM, programmed memory such as read-only memory (firmware), or on a data carrier such as an optical or electrical signal carrier. The code may be provided on a (non-transitory) carrier such as a disk, a microprocessor, CD- or DVD-ROM, programmed memory such as non-volatile memory (e.g. Flash) or read-only memory (firmware). Code (and/or data) to implement embodiments of the techniques may comprise source, object or executable code in a conventional programming language (interpreted or compiled) such as C, or assembly code, code for setting up or controlling an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array), or code for a hardware description language such as Verilog™ or VHDL (Very high speed integrated circuit Hardware Description Language). As the skilled person will appreciate, such code and/or data may be distributed between a plurality of coupled components in communication with one another. The techniques may comprise a controller which includes a microprocessor, working memory and program memory coupled to one or more of the components of the system.

Computer program code for carrying out operations for the above-described techniques may be written in any combination of one or more programming languages, including object oriented programming languages and conventional procedural programming languages. Code components may be embodied as procedures, methods or the like, and may comprise sub-components which may take the form of instructions or sequences of instructions at any of the levels of abstraction, from the direct machine instructions of a native instruction set to high-level compiled or interpreted language constructs.

Those skilled in the art will appreciate that while the foregoing has described what is considered to be the best mode and where appropriate other modes of performing present techniques, the present techniques should not be limited to the specific configurations and methods disclosed in this description of the preferred embodiment. Those skilled in the art will recognise that present techniques have a broad range of applications, and that the embodiments may 10 take a wide range of modifications without departing from the any inventive concept as defined in the appended claims.

Claims

1. A device for tracking an entity in a network comprising a set of devices, the device comprising:

at least one processor;

a communication module;

a power source; and a unique identifier identifying the device;

wherein the at least one processor and communication module are configured to:

switch the device into a first operation mode if the device is determined to be in motion or was recently in motion and has now become stationary, and communicate with the set of devices operationally connected to the device to determine a location of the device within the network; and switch the device into a second operation mode if the device is determined to be stationary and a location of the device within the network has been determined to a specified degree of accuracy.

2. The device as claimed in claim 1 wherein, when the device is in the second operation mode, the at least one processor and communication module are configured to:

communicate with at least one device of the set of devices operationally connected to the device to enable determination of a location of the at least one device within the network.

3. The device as claimed in claim 1 or 2 wherein the at least one processor and the communication module are configured to:

analyse signals received from a plurality of devices operationally connected to the device to determine if a signal strength of each signal is steady or fluctuating; and determine if the device is in motion or is stationary.

4. The device as claimed in claim 1 or 2 further comprising:

at least one sensor;

wherein the at least one processor and the communication module are configured to use data from the at least one sensor to determine if the device is in motion or is stationary.

5. The device as claimed in claim 4 wherein the at least one sensor comprises any one or more of: an accelerometer, a gyroscope, a gyrometer, a compass, a barometer and a magnetometer.

6. The device as claimed in claim 4 wherein the at least one sensor comprises a motion sensor.

7. The device as claimed in any one of claims 1 to 6 wherein the communication module uses a wireless communication protocol to communicate with the set of devices operationally connected to the device.

8. The device as claimed in any one of claims 1 to 6 wherein the communication module uses one or more of the following techniques to communicate with the set of devices operationally connected to the device: Bluetooth, Bluetooth Low Energy, Wi-Fi, Zigbee, 6L0WPAN, Thread, ZigBee, CoAP, GSM, GPRS, 2G, 3G, 4G and 5G.

9. The device as claimed in any one of claims 1 to 6 wherein the communication module comprises a radio communication system for communication with the set of devices operationally connected to the device.

10. The device as claimed in any preceding claim wherein, if the device is in the second operation mode, the at least one processor and communication module are configured to:

reduce a rate at which the device communicates with the set of devices operationally connected to the device to reduce power consumption of the device.

11. The device as claimed in any preceding claim further comprising at least one light energy harvesting module coupled to the power source and arranged to recharge the power source.

12. The device as claimed in claim 11 wherein the light energy harvesting module comprises at least one photovoltaic cell.

13. The device as claimed in claim 11 or 12 wherein the at least one energy harvesting module is configured to harvest energy from one or both of: ambient light, and sunlight.

14. The device as claimed in any preceding claim further comprising a user interface.

15. The device as claimed in claim 14 wherein the user interface is configured to indicate a low power warning to a user when the power source reports that a power level of the power source is below a predetermined level.

16. The device as claimed in claim 14 or 15 wherein the user interface comprises at least one button to set an operation mode or status of the device.

17. The device as claimed in any preceding claim further comprising a tamperproof alarm configured to emit a sound if the tampering is detected and/or to send a message to a remote server if the tampering is detected.

18. The device as claimed in any preceding claim further comprising an external casing for protecting the device.

19. The device as claimed in claim 18 wherein the external casing provides a hermetic seal around the device.

20. The device as claimed in claim 18 or 19 wherein the external casing is formed of an antibacterial polymer material.

21. The device as claimed in any preceding claim wherein the at least one processor and the communication module are configured to:

report to an external server when the device is nearing the end of its lifetime.

22. The device as claimed in any preceding claim further comprising: attachment means for coupling the device to an entity to be tracked.

23. The device as claimed in any preceding claim wherein the at least one processor and the communication module are configured to:

transmit messages to at least one reader device, each message comprising the unique identifier of the device, a current location of the device, and a status or operation mode of the device.

24. The device as claimed in any preceding claim wherein, if the device is determined to have been recently in motion, the at least one processor and the communication module are configured to gradually switch the device from the first operation mode into the second operation mode by:

determining an approximate location of the device;

improving, over a defined period of time, an accuracy of the approximate location of the device using signals received by the device from the set of devices operationally connected to the device; and switching the device into the second operation mode when the accuracy of the location of the device is within the specified degree of accuracy.

25. The device as claimed in claim 24 wherein when the device gradually transitions between the first operation mode and the second operation mode, the at least one processor and communication module are configured to:

communicate with at least one device of the set of devices operationally connected to the device to enable determination of a location of the at least one device within the network, and transmit data indicating the accuracy of the device location to the at least one device to enable the at least one device to weight any communications from the device.

26. A system for tracking entities in a network, the system comprising:

a plurality of devices according to claims 1 to 25;

at least one reader device configured to communicate with the plurality of devices to record the location and status of each device; and at least one server configured to communicate with each reader device to obtain and store the location and status of each device.

27. The system as claimed in claim 26 wherein the at least one server is configured to:

receive a request for device data from a third party; and provide device data responsive to the request.

28. A method for tracking an entity in a network using a tracking device coupled to the entity, the method of the tracking device comprising:

processing data to determine if the tracking device is in motion; and switching the device into a first operation mode if the tracking device is determined to be in motion or was recently in motion and has now become stationary, and communicate with a set of devices operationally connected to the tracking device to determine a location of the tracking device within the network; or switching the tracking device into a second operation mode if, responsive to processing the data, the tracking device is determined to be stationary and a location of the tracking device within the network has been determined to a specified degree of accuracy.

29. The method as claimed in claim 28 wherein, when the tracking device is in the second operation mode, the method further comprises:

communicating with at least one device of the set of devices operationally connected to the device to enable determination of a location of the at least one device within the network.

30. The method as claimed in claim 28 or 29 wherein the step of processing data to determine if the tracking device is in motion comprises:

analysing signals received from a plurality of devices operationally connected to the tracking device to determine if a signal strength of each signal is steady or fluctuating; and determining if the tracking device is in motion or is stationary.

31. The method as claimed in claim 28 or 29 wherein the step of processing data to determine if the tracking device is in motion comprises:

receiving motion data from at least one sensor; and using the motion data to determine if the tracking device is in motion or is stationary.

32. The method as claimed in any one of claims 28 to 31 wherein, if the device is in the second operation mode, the method comprises:

reducing a rate at which the tracking device communicates with the set of devices operationally connected to the tracking device to reduce power consumption of the tracking device.

33. The method as claimed in any one of claims 28 to 32 further comprising switching a state of the tracking device into one of the following states: an in-use state, an offline state, a low-power state, and a maintenance-required state.

34. The method as claimed in claim 33 wherein the step of switching a state of the tracking device is responsive to user instructions.

35. The method as claimed in claim 33 wherein the step of switching a state of the tracking device is responsive to one or more of the following: a current location of the tracking device, a current operation mode of the tracking device, a power level of the tracking device, and detection of a fault in the tracking device.

36. The method as claimed in claim 33 wherein the step of switching a state of the tracking device comprises switching the tracking device into a low-power state when the tracking device is determined to be in a location where real-time location tracking is not required, and wherein the method further comprises switching the tracking device into an online state when the tracking device is determined to no longer be in this location.

37. A non-transitory data carrier carrying code which, when implemented on a processor, causes the processor to carry out the method of any of claims 26 to 36.