Method for detecting falls and a fall detection system

1. A fall detection system comprising:

a user device configured to be worn or carried by a user, the user device comprising:

a plurality of proximity sensors for measuring a proximity of the user device to a ground or a floor; and

a movement sensor for measuring movements of the user; and

a processing unit configured to:

process the measurements from the movement sensor to detect whether the user may have suffered a fall;

activate the plurality of proximity sensors if it is detected that the user may have suffered a fall;

operate the plurality of proximity sensors to enable a direction of a beam formed by the plurality of proximity sensors to be varied or steered, and

process the measurements from the proximity sensors to determine if the user has fallen.

2. The fall detection system as claimed in claim 1 , wherein the processing unit is configured to process the movement sensor to detect whether the user may have suffered a fall by processing the movement sensor measurements to determine a change in a height and/or a magnitude of an impact, and it is detected that the user may have suffered a fall if the change in the height is greater than a first threshold value and/or the magnitude of the impact is greater than a second threshold value.

3. The fall detection system as claimed in claim 1 , wherein the processing unit is configured to process the measurements from the plurality of proximity sensors and the measurements from the movement sensor to determine if the user has fallen.

4. The fall detection system as claimed in claim 1 , wherein the plurality of proximity sensors are distributed in different orientations around the user device.

5. The fall detection system as claimed in claim 4 , wherein the processing unit is configured to activate each of the plurality of proximity sensors if it is detected that the user may have suffered a fall.

6. The fall detection system as claimed in claim 4 , wherein the processing unit is configured to, on detection that the user may have suffered a fall, process the measurements from the movement sensor to determine the orientation of the user device, determine which of the plurality of proximity sensors is facing downwards from the determined orientation, and activate the proximity sensor that is determined to be facing downwards.

7. The fall detection system as claimed in claim 4 , wherein each proximity sensor has an associated orientation sensor for determining an orientation of the proximity sensor, and wherein the processing unit is configured to measure the orientation of each proximity sensor using the orientation sensors, and to determine a direction in which each proximity sensor is facing from the measured orientations.

8. The fall detection system as claimed in claim 1 , wherein the plurality of proximity sensors face a same direction to form an array, and wherein the processing unit is configured to operate the array of proximity sensors together to enable a width of a viewing direction of the array to be changed.

9. The fall detection system as claimed in claim 8 , wherein the processing unit is configured to operate the array to steer a direction of a beam formed by the array.

10. The fall detection system as claimed in claim 8 wherein the processing unit is configured to control the array to measure a distance to an object in different directions, and to process the distance measurements in different directions to determine an extent or extendedness of the object.

11. The fall detection system as claimed in claim 8 , wherein the processing unit is configured to control the array to measure a distance to an object in different directions, and to determine an extent or extendedness of the object from a strength of a received echo as a function of a relative phase of the beam.

12. The fall detection system as claimed in claim 10 , wherein the processing unit is configured to determine whether the distance measured by the array of proximity sensors is a distance to the ground, the floor or another object from the determined extent or extendedness of the object.

13. The fall detection system as claimed in claim 12 , wherein the processing unit is configured to use a result of the processing to determine whether the distance measured by the object is to the ground, the floor or another object in the processing of the measurements from the proximity sensor and the measurements from the movement sensor to determine if the user has fallen.

14. A method for detecting falls, the method comprising:

measuring movements of a user using a movement sensor;

processing the measurements from the movement sensor to detect whether the user may have suffered a fall;

if it is detected that the user may have suffered a fall, activating a plurality of proximity sensors that measures a proximity of a user device to a ground or a floor;

operating the plurality of proximity sensors to enable a width of a viewing direction of the array to be changed; and

processing the measurements from the proximity sensor to determine if the user has fallen.

15. A non-transitory computer readable medium encoded computer executable instructions, which, when executed by a processor, causes the processor to:

measure movements of a user using a movement sensor;

process the measurements from the movement sensor to detect whether the user may have suffered a fall;

if it is detected that the user may have suffered a fall, activate a plurality of proximity sensors that measures a proximity of a user device to a ground or a floor;

operate the plurality of proximity sensor to determine if the user has plurality of proximity sensors to be varied or steered; and

process the measurements from the proximity sensor to determine if the user has fallen.