Device for tracking a person by using contextualised activity measurements

1 . A device for monitoring a status of a user, with the user occupying an environment, the device comprising:

a mobile module, configured to be worn by the user; and

beacons, distributed in the environment, configured to send a transmission signal to the mobile module via a short-range wireless connection;

the mobile module comprising:

a short-range wireless connection unit, configured to receive at least one transmission signal transmitted by at least one beacon;

a range-finding unit, configured to estimate, at different measurement times, a distance between the mobile module and the at least one beacon whose transmission signal is received by the mobile module;

at least one activity sensor of the user, configured to establish an activity signal representing an activity of the user at each measurement time;

wherein the device further comprises:

a processing unit, configured to establish a position signal as a function of at least one distance estimated by the range-finding unit, at each measurement time, with the position signal representing a position of the user relative to the environment; and

a transmission unit, configured to transmit the position signal and the activity signal to a central unit;

wherein the central unit is configured to:

determine the status of the user, from both of the position signal and the activity signal, the status of the user being selected from among a plurality of predetermined statuses, the status of the user being at least one of:

a physical activity undertaken by the user at the measurement time;

a stress status of the user at the measurement time; and

a physiological status of the user at the measurement time; and

characterize the status of the user.

2 . The device of claim 1 , wherein characterizing the status is one of:

estimating a duration of the status; and

analyzing at least one activity signal of the user during the status.

3 . The device of claim 1 , wherein at least one beacon is a privacy beacon, the device being programmed such that when the mobile module is arranged at a distance from the privacy beacon that is below a threshold distance, no position signal and no activity signal is transmitted to the central unit.

4 . The device of claim 1 , wherein the activity sensor comprises at least:

a motion sensor; and/or

a cardiac activity sensor; and/or

a muscle activity sensor; and/or

a brain activity sensor; and/or

a blood pressure sensor; and/or

an analyte sensor.

5 . The device of claim 1 , wherein the range-finding unit is configured to estimate a distance between the mobile module and the at least one beacon as a function of the strength or the power of the transmission signal sent by the beacon to the mobile module.

6 . The device of claim 5 , wherein:

the mobile module comprises an orientation unit, configured to estimate an orientation of the mobile module; and

the range-finding unit takes into account an orientation of the mobile module to estimate the distance of the mobile module and each beacon whose transmission signal is received by the mobile module.

7 . The device of claim 1 , wherein the range-finding unit is configured to estimate several distances between the mobile module and respectively several beacons as a function of transmission signals respectively transmitted by each beacon to the mobile module.

8 . The device of claim 7 , wherein the processing unit is configured such that the position signal corresponds to a position of the mobile module relative to several beacons.

9 . The device of claim 1 , wherein the short-range wireless connection is a connection with a range of less than 50 meters or 30 meters.

10 . The device of claim 1 , wherein:

the at least one beacon comprises an ambience sensor, configured to measure a temperature and/or a sound level and/or a light level;

the at least one beacon is configured to transmit an ambience signal to the mobile module that is dependent on the measurement carried out by the ambience sensor; and

the processing unit is programmed to assign an ambience level to each status signal that is dependent on the ambience signal.

11 . The device of claim 1 , wherein:

the at least one beacon is configured to receive an identification signal transmitted by at least one other beacon, with the power of the identification signal being dependent on a distance between the two beacons;

the at least one beacon is configured to transmit a transmission signal comprising a relative position signal, with the relative position signal being determined from a power of each identification signal received by the at least one other beacon; and

the mobile module is configured to transmit the relative position signal to the processing unit.

12 . The device of claim 1 , wherein:

the processing unit and transmission unit are enclosed within the mobile module;

the mobile module is configured to switch between:

a reception mode, in which the short-range wireless connection unit receives at least one transmission signal transmitted by at least one beacon; and

a transmission mode, wherein the transmission unit transmits the activity signal and/or the position signal, at each measurement time, to the central unit; and

the mobile module is configured such that:

when the duration of the transmission mode exceeds a predetermined duration, the transmission mode is interrupted, so as to allow switching from the transmission mode to the reception mode; and

following the reception of at least one transmission signal, the module switches from the reception mode to the transmission mode, so as to continue the transmission to the central unit.

13 . A method for monitoring the status of the user of the device of claim 1 , wherein the user is placed in the environment, with the user wearing the mobile module of the device, with several beacons of the device being distributed in the environment, the method comprising, for at least one measurement time:

a) measuring an activity of the user, using at least one activity sensor of the mobile module, and generating an activity signal therefrom;

b) estimating a distance between the mobile module and at least one beacon;

c) determining, from the distance or from each distance estimated in b), a position signal representing a position of the user in the environment;

d) determining, with a central unit, a status of the user, from both of the position signal and the activity signal, the status of the user being selected from among a plurality of predetermined statuses, the status of the user representing at least one of:

a physical activity undertaken by the user at the measurement time;

a stress status of the user at the measurement time; and

a physiological status of the user at the measurement time; and

e) characterizing, with the central unit, the status of the user.

14 . The method of claim 13 , wherein characterizing the status of the user is one of:

estimating a duration of the status; and

analysing at least one activity signal of the user during the status.

15 . The method of claim 13 , wherein the at least one beacon is a privacy beacon, with the device being programmed such that when the mobile module is placed at a distance from the privacy beacon that is below a threshold distance, no activity signal and no position signal is transmitted to the central unit.

16 . The method of claim 13 , wherein the at least one beacon is fixed in the environment.

17 . The method of claim 13 , wherein the at least one beacon is worn by a third party, other than the user.

18 . The method of claim 13 , wherein:

the environment comprises an object, likely to be in contact with the user or handled by at least one user; and

the at least one beacon is attached to the object.

19 . A method for monitoring a status of a plurality of users, with each user of the plurality of users using the device of claim 1 , the each user being placed in an environment, the each user wearing the mobile module of the device, with several beacons of the device being distributed in the environment of the each user, the method comprising, for the each user, at different measurement times:

a) measuring an activity of the each user, using at least one activity sensor of the mobile module, and generating an activity signal therefrom;

b) estimating a distance between the mobile module and at least one beacon;

c) determining, from the distance or from each distance estimated in b), a position signal representing a position of the each user in the environment;

d) determining a status of the each user, from both of the position signal and the activity signal, the status of the each user being selected from among a plurality of predetermined statuses, the status of the each user representing at least one of:

a physical activity undertaken by the each user at the measurement time;

a stress status of the each user at the measurement time; and

a physiological status of the each user at the measurement time;

e) characterizing, with the central unit, the status of the each user;

the method comprising, after carrying out steps a) to e), for the plurality of users, and at different measurement times:

taking into account a predetermined task;

selecting, for the each user, measurement times during which the status of the each user corresponds to said task, with the measurement times selected for the each user forming at least one time range specific to the each user; and

characterizing the activity of the each user during one time range specific to the each user.

20 . The method of claim 19 , wherein characterizing the status is one of:

estimating a duration of the status; and

analysing at least one activity signal of the each user during the status.