WO2015040355A1

WO2015040355A1 - Apparatus and method for location identification

Info

Publication number: WO2015040355A1
Application number: PCT/GB2013/052484
Authority: WO
Inventors: Martin KENWRIGHT
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-09-23
Filing date: 2013-09-23
Publication date: 2015-03-26
Anticipated expiration: 2016-03-23
Also published as: GB201605175D0; GB2533738A

Abstract

A system for generating a 3-D map of a plurality of loci within a structure includes a triangulation network associated with the structure whereby each locus may be assigned co- ordinates corresponding to its position within the structure relative to the triangulation network, and a portable mapping device,arranged for determining the location for each locus from a position of the portable mapping device relative to the triangulation network and a position of each locus relative to the portable mapping device, and arranged for storing the location for each locus in a memory. The system may then be used to subsequently guide a user within the structure to the loci identified by the labels. The system is useful for assisting a visually-or memory-impaired user to find objects and locations within a structure such as a dwelling.

Description

Apparatus and Method for Location Identification

BACKGROUND The present invention relates to systems, methods and portable mapping devices for assisting users to locate objects within structures such as dwellings. In particular, the invention is concerned with systems for guiding a visually-impaired or memory-impaired user to the locations of objects. FIELD

Many people, as a result of disease or ageing, suffer from impairment to their visual acuity and/or to their short-term memory. In many cases, these ailments may be combined within a single person. A result of this is that such impaired individuals may have difficulty in locating objects within their surroundings, such as within their dwelling place.

As a result of this, it may become necessary for such individuals to rely upon carers in order for them to carry out daily tasks required for survival in the home or in a care facility. The need for an increasing number of full time carers leads to a considerable drain on society's resources in a situation where the average age of the population is increasing and a greater proportion of the population is suffering from ailments leading to memory impairment and visual impairment. Hence, there is a need to provide technical solutions which may allow such impaired in visual individuals to carry out daily tasks with a reduced need to rely upon carers to assist them with such tasks.

It is known to use global positioning satellite systems in order to assist in the guidance of users to geographic locations. Is also known to use triangulation networks based upon WiFi networks or mobile telephone cells in order to provide information relating to the geographical locations of devices such as mobile telephones.

SUMMARY

It is one aim of the present invention, amongst others, to provide systems, methods and apparatus for assisting in the guidance of a visually- or memory-impaired user to loci within a structure. In particular, it is an object of the invention to assist such a user in the location of specific objects and regions within a structure such as a dwelling. 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. Throughout this specification, the term "comprising" or "comprises" means including the components) specified but not to the exclusion of the presence of other components. The term "consisting essentially of or "consists essentially of means including the components specified but excluding other components except for components added for a purpose other than achieving the technical effect of the invention. The term "consisting of or "consists of means including the components specified but excluding other components.

Whenever appropriate, depending upon the context, the use of the term "comprises" or "comprising" may also be taken to include the meaning "consists essentially of or "consisting essentially of, and also may also be taken to include the meaning "consists of or "consisting of.

The optional features set out herein may be used either individually or in combination with each other where appropriate and particularly in the combinations as set out in the

accompanying claims. The optional features for each aspect or exemplary embodiment of the invention, as set out herein are also applicable to any other aspects or exemplary

embodiments of the invention, where appropriate. In other words, the skilled person reading this specification should consider the optional features, set out in relation to each aspect or embodiment of the invention, as interchangeable and combinable between different aspects and embodiments of the invention unless such a combination is clearly inappropriate.

A first aspect of the invention provides a system for providing guidance of a user to locations of a plurality of loci within a structure, the system comprising:

a triangulation network associated with the structure whereby each locus may be assigned coordinates corresponding to its location relative to the triangulation network and hence relative to the structure, and

a portable mapping device, arranged for determining the location for each locus from a position of the portable mapping device relative to the triangulation network and a position of each locus relative to the portable mapping device, and arranged for storing the location for each locus in a memory upon input of a storage command,

wherein the portable mapping device is also arranged for recording a label for each locus and for storing the label for each locus linked to the location of the respective locus stored in the memory, and wherein the portable mapping device is arranged to provide guidance of the user to a location of a specific locus of the plurality of loci in response to input of a guidance command identifying the specific locus. As used herein, the term "system" refers to a collection or assembly of apparatus intended for use together as a jointly-operating device. It will be understood that the system may include components from different sources or supplers, and so, for instance, the system of the first aspect of the apparatus may employ a conventional smartphone or the like as the basis for the portable mapping device, with the smartphone running a computer programme or application whereby it is arranged to carry out the operations required for the first aspect of the invention in combination with a triangulation network.

The structure may be any suitable structure, for instance a vessel or a dwelling structure, and may typically be a building with one or more floors. The structure is preferably a dwelling.

A triangulation network is associated with the structure whereby each locus may be assigned co-ordinates corresponding to its location relative to the triangulation network and hence relative to the structure. Each locus may be a specific fixed point in the structure identifiable by a co-ordinate set relative to the triangulation network.

Triangulation networks are known in the prior art, and may comprise, for instance, a plurality of senders or beacons emitting electromagnetic waves, with the waves from each sender overlapping and mutually interfering. The co-ordinates of a particular point within the triangulation network may be obtained by various means such as by amplitude measurement, phase measurement, interference pattern location or the like.

The system includes a portable mapping device, arranged for determining the location for each locus from a position of the portable mapping device relative to the triangulation network and a position of each locus relative to the portable mapping device, and arranged for storing the location for each locus in a memory upon input of a storage command.

In one simple arrangement, the portable mapping device may be located at or near the locus to be stored, so that the position of the portable mapping device may be the same as the location of the locus to be stored.

The portable mapping device is also arranged for recording a label for each locus and for storing the label for each locus linked to the location of the respective locus stored in the memory. The label may refer to the name of a part of the structure, or may, for instance, refer to the name of an object which is temporarily positioned at the stored locus. In this way, the system provides the capability for a locus and an object to be linked at storage so that the portable mapping device can later retrieve a locus associated with a particular object whereby the user may be guided to that object by guiding the user to the associated locus. Hence, the portable mapping device is arranged to provide guidance of a user to a location of a specific locus of the plurality of loci in response to input of a guidance command identifying the specific locus, for instance identifying the desired object.

The guidance command may be a guidance command identifying the specific locus by a word related to the label of that locus. The guidance command may be a voice command for guidance from the user.

So, for instance, if the word "spectacles" is associated with a particular locus as the label stored with the location co-ordinates of that locus, then the input of a guidance command including the word "spectacles" or a synonym such as "glasses" or "eyeglasses" may prompt the portable mapping device to provide guidance instructions to the user to guide the user to the location associated with the label.

If there is more than one location associated with a label, then the portable mapping device may be arranged to interrogate the user for further detail. For instance requesting specification as to whether the location of "reading glasses" or "sunglasses" is required. Known voice recognition software may be employed for input of commands and interrogation of the used.

The triangulation network may suitably comprise a plurality of WiFi base stations located within the structure, such as at least three such base stations, for instance four or more base stations.

A plurality of reference markers may also be located within the structure, wherein the portable mapping device is arranged to calculate the position of the portable mapping device relative to the triangulation network based on a position determined relative to the triangulation network and a position of the portable mapping device relative to the one or more of the reference markers. It will be understood that the location accuracy of a triangulation system based on electromagnetic waves may have a limited resolution, for instance depending upon the wavelength used, and so in order to improve the accuracy for recorded locations, supplementary information may be gathered from reference markers which are positioned in the structure at locations which are already known. The reference markers may, for instance, include a code readable by the portable mapping device, whereby the identity, and hence the known location, of a particular reference marker may be established. Typically, for instance, a code such as a Quick Response (QR™) code or barcode may be employed. The portable mapping device may also comprises a means for measuring a movement of the portable mapping device relative to the triangulation system and a means for calculating the position of the portable mapping device from an initial position and the movement. A suitable such means for measuring movement of the portable mapping device is an accelerometer. Hence, in order to improve the accuracy of the stored locations for loci, the user may be prompted, for instance, to position the portable mapping device at or near a reference marker and then prompted to move to the locus to be recorded.

It will be understood that the portable mapping device may be programmed to obtain the most accurate co-ordinates available based upon a combination of information from the triangulation network, information from reference markers and information from the means for measuring movement.

The storage command may be a voice command for storage. The portable mapping device may include an output means arranged for prompting the user for commands. For instance, for a memory-impaired user, there may be a reminder list which is played back to the user at regular intervals in order to prompt the user to ensure that certain items are still with the user.

The portable mapping device may comprise a display means and may further comprise a map of the structure arranged for simultaneous display of a 2-D representation of the structure and of the location of the specific locus and the location of the portable mapping device, relative to the structure.

The portable mapping device may be arrangeable to be operated in a mapping mode for input of details of the map of the structure. So, for instance, prior to use by a memory- or visually- impaired user, the map of the structure may be recorded onto the portable mapping device by a person other than the impaired user following instructions from the portable mapping device to generate the map, for instance by conducting a systematic walk-through of the structure. The portable mapping device may be arranged to switch between a recording mode and a guidance mode in response to a switching input from a user. For instance, this switching may be initiated by input of a verbal command starting "where are... ?" or "where is....?" to put the portable mapping device into guidance mode. For instance the switching to recording mode may be initiated by input of a verbal instruction starting "remember where...." Or "store location of... "

The portable mapping device may be arranged to provide a route for the user from a current location of the portable mapping device to the location of the specific locus. For instance, the route may be arranged for display on the display means along with the 2-D representation of the structure. For instance, the portable mapping device may be arranged to provide the route to the user as a set of instructions for movement.

In an embodiment, the portable mapping device may be arranged to provide the set of instructions sequentially as audio instructions as the user progresses along the route.

The map of the structure may comprise a plurality of regions each associated with a region name. These regions may be input along with the generation of the map of the structure, or separately therefrom, whilst the portable mapping device is operated in a mapping mode for input of details of the map of the structure. So, for instance, prior to use by a memory- or visually-impaired user, regions of the map of the structure may be recorded onto the portable mapping device by a person other than the impaired user following instructions from the portable mapping device to generate the map, for instance by conducting a systematic walkthrough of the structure.

For instance, the regions may be areas or spaces such as rooms, e.g. "kitchen", "Michael's room", "toilet", or may be regions that have been designated as hazardous, such as "kettle" or "electric fire" or "stove". The portable mapping device may be arranged to provide the respective region name to the user through an audio signal or visual display when the portable mapping device moves into one of the plurality of regions, or at intervals whilst the user remains in the respective region.

The portable mapping device may be arranged to provide guidance of the user to a requested region in response to a guidance command identifying the requested region by referring to a region name.

The portable mapping device may be arranged to provide an alarm signal when the portable mapping device moves into a predetermined one of the plurality of regions. For instance, the device may be arranged to give warning of risk areas such as hot surfaces or areas where the user is at risk of falling (for instance at the approach to a staircase, basement door, etc.) The portable mapping device may be arranged to transmit the alarm signal to the user and/or to a remote monitor. For instance this transmission to a remote monitor may be achieved through the SMS messaging system using a SIM in the portable mapping device, or an e-mail message or the like may be dispatched from the portable mapping device.

The portable mapping device may be arranged for storing the position of the mapping device as the location of the locus when the portable mapping device is positioned at the respective locus. Hence, the user merely needs to ensure that the portable mapping device is placed at or near, say within 1 metre, of the locus, the location of which is to be recorded, along with a label relating to that locus or object at that locus. The device may prompt the user to place the device adjacent to or near to the object whose locus is to be recorded. In an exemplary embodiment, the portable mapping device may be arranged to determine the location of each locus by calculation from the position of the portable mapping device, an orientation of the portable mapping device and distance from the portable mapping device to the locus, wherein the portable mapping device includes a means for measuring the orientation of the portable mapping device.

For instance, the device may prompt the user to enter an estimate of the distance to the device when entering a label and may prompt the user to align the device to point at the object or locus to record an orientation of the device. The portable mapping device may further include a means for measuring the position of the locus relative to the position of the portable mapping device, such as a laser measurement device known in the art.

In a preferred exemplary embodiment of the first aspect of the invention, the portable mapping device may comprise a headset adapted for wear by the user.

The portable mapping device, for this exemplary embodiment according to the invention, may be arranged to determine the location of each locus by calculation from the position of the headset and a direction and distance from the headset to the locus, whilst the user's eyes are directed onto the respective locus and wherein the headset includes a means for measuring the position of the locus relative to the position of the headset. For instance, this may be by means of a compass and laser measuring device, or may be derived, for instance, from analysis of the user's eye configuration, by monitoring of the position of the eyes and calculating the point upon which their view converges.

The portable mapping device is arranged to provide instructions to the user to direct the user's eyes onto the respective locus whilst inputting a label for the respective locus, whereby the location of the locus may be determined, relative to the position of the headset. The headset may comprise a heads-up display means arranged for simultaneous display of a 2-D representation of the structure and of the location of the specific locus and the location of the portable mapping device, relative to the structure. The headset may be in the form a pair of spectacles arranged to include a heads-up display through lenses of the spectacles.

The headset may comprise an image recognition means arranged to identify and notify an object viewed by the user, through the headset, to the user.

The portable mapping device of the first aspect of the invention, whether a headset or otherwise, may be arranged to provide an alarm signal when the portable mapping device moves to a co-ordinate position outside of the structure. The portable mapping device may further comprise a GPS location identifier and a sender for transmitting a GPS location determined by the GPS location identifier to a remote monitor. The sender may be arranged to transmit the GPS location to the remote monitor when the portable mapping device moves to a co-ordinate position outside of the structure. In this way, a carer at a remote location may be warned that the user is straying outside the structure. For instance this may be achieved through the SMS messaging system using a SIM in the portable mapping device, or an e-mail message or the like may be dispatched from the portable mapping device.

A second aspect of the invention provides the use of the system of the first aspect of the invention to provide guidance to a memory-impaired user, or, in a third aspect, to a vision- impaired user.

A fourth aspect of the invention provides a method for providing a user with guidance to the location of one of a plurality of loci within a structure, the method comprising:

providing a triangulation network fixed within the structure whereby each locus may be assigned co-ordinates corresponding to its location relative to the triangulation network and hence relative to the structure, and

providing a portable mapping device arranged for determining the location for each locus from a position of the portable mapping device relative to the triangulation network and and a position of each locus relative to the portable mapping device,

storing the location for each locus in a memory upon a storage command from the user, recording a label for each locus and storing the label for each locus linked to the location of the respective locus stored in the memory, and

providing guidance from the portable mapping device to guide the user to the location of a specific one of the plurality of loci in response to a guidance command from the user identifying the specific locus.

The preferred or optional features set out in relation to the first aspect of the invention are specifically disclosed in combination with this fourth aspect of the invention. A fifth aspect of the invention provides a portable mapping device arranged for use with the system or method of the invention as set out hereinbefore, with the optional or preferred features relating to the headset, as set out hereinbefore, also relating to this fifth aspect. The portable mapping device of the fifth aspect of the invention may comprise a computing means arranged to run a computer program comprising computer readable instructions configured to cause the portable mapping device to carry out the method of the invention as set out above. The portable mapping device may include a computer apparatus comprising: a memory storing processor readable instructions; and a processor arranged to read and execute instructions stored in the memory; wherein the processor-readable instructions comprise instructions arranged to control the portable mapping device to carry out the method of the invention. A further aspect of the invention provides a computer program comprising computer readable instructions configured to cause the portable mapping device according to the invention to carry out a method according to the invention. Also provided as an aspect of the invention is a computer readable medium carrying a computer program according to the invention. BRIEF DESCRIPTION OF DRAWINGS

For a better understanding of the invention, and to show how exemplary embodiments of the same may be carried into effect, reference will be made, by way of example only, to the accompanying diagrammatic Figures, in which:

Figure 1 schematically depicts a 2-D representation of a dwelling;

Figure 2 schematically depicts a smartphone used as a portable mapping device according to an embodiment of the invention;

Figures 3 and 4 schematically depict a user wearing a portable mapping device, according to an embodiment of the invention, in the form of a pair of glasses.

DETAILED DESCRIPTION

Figure 1 shows a schematic representation of the ground floor 2 and first floor 3 of a dwelling 1 , with the walls of rooms indicated by solid lines. Figure 2 shows a schematic representation of a portable mapping device 9 according to an embodiment of the invention according to this embodiment of the invention, the portable mapping device 9 having a display screen 15 and a microphone 16 for input of voice control commands.

A triangulation system is provided by four Wi-Fi base stations 4 is shown in Figure 1 . Doors 5 providing entrance to, or exit from, the building are present on the ground floor 2. Internal doors are shown by broken lines 6. The region 7, indicated on the first floor 3 represents an area where stairs are present leading from the upstairs first floor down to the ground floor 2. The user 8 is shown holding a portable mapping device 9 and is standing adjacent to a first object 1 1 , say a briefcase.

In order to record the location of the object 1 1 , in this first embodiment, the user 8 stands adjacent to the object 1 1 , or places the portable mapping device 9 close to the object 1 1 and using voice control, says "remember where the briefcase is... ". The voice control software then uses the label "briefcase" and associates it with the coordinates of the portable mapping device and 9 as established by the portable mapping device 9 in relation to the triangulation network formed by the base stations 4. In this manner, the location of the briefcase 1 1 is stored along with a label.

They will be understood that in this manner, the user, or a carer, can store the locations of the loci of a variety of objects, each associated with an easily remembered label.

A second object (wallet) 10 is also shown present on the ground floor 2 of the dwelling. In order to be guided to the location of the wallet 10, the user 8, using voice control with the portable mapping device 9, says "where is my wallet?". The voice control software then searches for the label "wallet" which has previously been recorded within the storage memory of the portable mapping device known and identifies a record where the label "wallet" has been previously associated with a location relative to the translation network.

Referring now to Figure 2, in response to the voice control request from the user 8, the portable mapping device 9 then displays a 2-D map 12 to the user 8, on the display screen 15 of the portable mapping device 9, with an icon indicating the current position of the user 13 relative to the 2-D map and the location of the object which the user wants to find, relative to the 2-D map, as a flashing icon 14. Figure 3 shows another embodiment according to the invention, where the portable mapping device 9' is in the form of a headset configured as a pair of glasses including a microphone 17 for input of instructions by the user. With this embodiment of the invention, rather than that the user 8 placing the portable mapping device 9' to be at or near the object whose locus is to be recorded, the portable mapping device 9' is configured to calculate the coordinates x', y', z' of the locus of the object 1 1 from the coordinates of the headset 9', (x, y, z) relative to the triangulation network 4 and the orientation of the headset 9', as measured by a compass device contained within the headset (not shown), when the user is looking at the object 1 1 . The distance between the object 1 1 and the headset 9' may be measured, for example, using a laser measurement device in the headset (not shown), or may be calculated from the position of the user's eyes as monitored by the headset. In an embodiment, the headset may prompt the user to estimate and states a distance between the headset and the object, with the headset using the stated distance for calculation purposes. Figure 4 shows how a headset 9' according to an embodiment of the invention may be used with a reference marker order to improve the accuracy of the identification of the location of the headset within a structure. The headset 9' is arranged to calculate the position of the headset 9' relative to the triangulation network based on a position determined relative to the triangulation network (x,y,z) and a position of the portable mapping device relative to the more accurately known predetermined location of the reference marker 18 (a,b,c). It will be understood that the location accuracy of a triangulation system based on electromagnetic waves may have a limited resolution, for instance depending upon the wavelength used, and so in order to improve the accuracy for recorded locations, supplementary information in this embodiment is gathered from the reference marker 18 which is positioned in the structure at a known or predetermined location already stored in the headset 9'. The reference marker 18 includes a code readable by the headset 9', whereby the identity, and hence the known location, of the reference marker 18 is established. The headset 9' is programmed to use, as its accurate location, either the location relative to the triangulation network or the location relative to the reference marker 18 based upon an estimate of which is most accurate at any particular time.

Although a few exemplary 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. For example, although in the embodiments set out above, it has been assumed that the memory is located within the portable mapping device 9, 9' the memory may instead be located in a remote computer with the portable mapping device communicating with the remote computer wirelessly. 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, 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, and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1 . A system for providing guidance of a user to locations of a plurality of loci within a structure, the system comprising:

a triangulation network associated with the structure whereby each locus may be assigned co-ordinates corresponding to its location relative to the triangulation network and hence relative to the structure, and

wherein the portable mapping device is also arranged for recording a label for each locus and for storing the label for each locus linked to the location of the respective locus stored in the memory, and

wherein the portable mapping device is arranged to provide guidance of said user to a location of a specific locus of the plurality of loci in response to input of a guidance command identifying the specific locus.

2. The system of claim 1 wherein the guidance command is a guidance command identifying the specific locus by a word related to the label of that locus.

3. The system of claim 2 wherein the guidance command is a voice command for guidance from said user.

4. The system of any preceding claim wherein the triangulation network comprises a plurality of WiFi base stations located within the structure.

5. The system of claim any preceding claim wherein a plurality of reference markers are located within the structure and wherein the portable mapping device is arranged to calculate the position of the portable mapping device relative to the triangulation network based on a position determined relative to the triangulation network and a position of the portable mapping device relative to the one or more of the reference markers.

6. The system of claim 5 wherein the portable mapping device comprises a means for measuring a movement of the portable mapping device relative to the triangulation system and a means for calculating the position of the portable mapping device from an initial position and the movement.

7. The system of any preceding claim wherein the structure is a dwelling.

8. The system of any preceding claim wherein the storage command is a voice command for storage.

9. The system of any preceding claim wherein the portable mapping device includes an output means arranged for prompting said user for commands.

10. The system of any preceding claim wherein the portable mapping device comprises a display means and further comprises a map of the structure arranged for simultaneous display of a 2-D representation of the structure and of the location of the specific locus and the location of the portable mapping device, relative to the structure.

1 1 . The system of claim 10 wherein the portable mapping device is arrangeable for operation in a mapping mode for input of details of the map of the structure.

12. The system of any preceding claim wherein the portable mapping device is arranged to switch between a recording mode and a guidance mode in response to a switching input.

13. The system of any preceding claim wherein the portable mapping device is arranged to provide a route for said user from a current location of the portable mapping device to the location of the specific locus.

14. The system of claim 13 wherein the route is arranged for display on the display means with the 2-D representation of the structure.

15. The system of claim 13 or claim 14 wherein the portable mapping device is arranged to provide the route to said user as a set of instructions for movement.

16. The system of claim 15 wherein the portable mapping device is arranged to provide the set of instructions sequentially as audio instructions as said user progresses along the route.

17. The system of any one of claims 10 to 16 wherein the map of the structure comprises a plurality of regions each associated with a region name.

18. The system of claim 17 wherein the portable mapping device is arranged to provide the respective region name to said user through an audio signal or visual display when the portable mapping device moves into one of the plurality of regions, or at intervals whilst said user remains in the respective region.

19. The system of claim 17 or claim 18 wherein the portable mapping device is arranged to provide guidance of said user to a requested region in response to a guidance command identifying the requested region by referring to a region name.

20. The system of any one of claims 17 to 19 wherein the portable mapping device is arranged to provide an alarm signal when the portable mapping device moves into a predetermined one of the plurality of regions.

21 . The system of claim 20 wherein the portable mapping device is arranged to transmit the alarm signal to a remote monitor.

22. The system of any preceding claim wherein the portable mapping device is arranged for storing the position of the mapping device as the location of the locus when the portable mapping device is positioned at the respective locus.

23. The system of any one of claims 1 to 21 wherein the portable mapping device is arranged to determine the location of each locus by calculation from the position of the portable mapping device, an orientation of the portable mapping device and distance from the portable mapping device to the locus, wherein the portable mapping device includes a means for measuring the orientation of the portable mapping device and a means for measuring the position of the locus relative to the position of the portable mapping device.

24. The system of claim 23 wherein the portable mapping device comprises a headset adapted for wear by said user.

25. The system of claim 24 wherein the headset is arranged to determine the location of each locus by calculation from the position of the headset an orientation of the headset and distance from the headset to the locus, whilst said user's eyes are directed onto the respective locus.

26. The system of claim 25 wherein the portable mapping device is arranged to provide instructions to said user to direct said user's eyes onto the respective locus whilst inputting a label for the respective locus.

27. The system of any one of claims 24 to 26 wherein the headset comprises a heads-up display means arranged for simultaneous display of a 2-D representation of the structure and of the location of the specific locus and the location of the portable mapping device, relative to the structure.

28. The system of claim 27 wherein the headset is a pair of spectacles arranged to include a heads-up display through lenses of the spectacles.

29. The system of any one of claims 24 to 28 wherein the headset comprises an image recognition means arranged to identify and notify an object viewed by said user, through the headset, to said user.

30. The system of any preceding claim wherein the wherein the portable mapping device is arranged to provide an alarm signal when the portable mapping device moves to a co-ordinate position outside of the structure.

31 . The system of any preceding claim wherein the portable mapping device further comprises a GPS location identifier and a sender for transmitting a GPS location determined by the GPS location identifier to a remote monitor.

32. The system of any preceding claim wherein the sender is arranged to transmit the GPS location to the remote monitor when the portable mapping device moves to a co-ordinate position outside of the structure.

33. The use of the system of any preceding claim to provide guidance to a memory- impaired user.

34. The use of the system of any preceding claim to provide guidance to a vision-impaired user.

35. A method for providing a user with guidance to the location of one of a plurality of loci within a structure, the method comprising:

providing a portable mapping device arranged for determining the location for each locus from a position of the portable mapping device relative to the triangulation network and a position of each locus relative to the portable mapping device,

providing guidance from the portable mapping device to guide the user to the location of a specific one of the plurality of loci in response to a guidance command from said user identifying the specific locus.

36. A portable mapping device arranged for use with the system of any one of claims 1 to 32 or the method of claim 35.

37. The portable mapping device of claim 36 comprising a computing means arranged to run a computer program comprising computer readable instructions configured to cause the portable mapping device to carry out the method according to claim 35.

38. The portable mapping device of claim 37 including a computer apparatus comprising: a memory storing processor readable instructions; and

a processor arranged to read and execute instructions stored in said memory;

wherein said processor readable instructions comprise instructions arranged to control the portable mapping device to carry out a method according to claim 35.

39. A computer program comprising computer readable instructions configured to cause a portable mapping device according to any one of claims 36 to 38 to carry out a method according to claim 35.

40. A computer readable medium carrying a computer program according to claim 39.

41 . A system, method, portable mapping device or computer program substantially as described herein and with reference to and as shown in the accompanying Figures.