Methods and apparatus for detecting a fall of user
View Patent ↗This invention relates to methods and apparatus for detecting a fall of a user, especially to methods and apparatus for detecting a fall of a user by using pressure sensors. This invention discloses an apparatus for detecting a fall of a user, and the apparatus comprises first and second pressure sensors configured to obtain first and second data values of atmosphere pressure and intended to be worn on the body of the user, and a processor configured to derive a third data value of atmosphere pressure for determining whether a fall occurs or not from the first and second data values of atmosphere pressure. The first and second pressure sensors are configured in a way such that preset orientations of the first and second pressure sensors are opposite to each other. In this way, the weight of measuring elements comprised in the first and second pressure sensors have opposite effects on the measured atmosphere pressure, and thus (?) the measurement error caused by pressure sensor orientation variation can be reduced or even eliminated.
1. An apparatus for detecting a fall of a user, the apparatus comprising:
first and second pressure sensors configured to obtain first and second data values of atmosphere pressure; and
a processor configured to derive, from the first and second data values of atmosphere pressure, a third data value of atmosphere pressure indicating a change in altitude indicative of a fall;
wherein the first and second pressure sensors are configured in a way such that preset orientations of the first and second pressure sensors are opposite to each other.
2. The apparatus as claimed in claim 1 , wherein the third data value of atmosphere pressure is derived by calculating the average of the first and second data values of atmosphere pressure.
3. The apparatus as claimed in claim 1 , wherein the third data value of atmosphere pressure is derived by calculating weight values assigned to the first and second data values of atmosphere pressure.
4. The apparatus as claimed in claim 3 , wherein the weight values are determined based on an orientation of the first and second pressure sensors.
5. The apparatus as claimed in claim 1 , wherein each pressure sensor comprises a pressure sensing element with an atmosphere pressure sensing surface, surface and the preset orientation is the normal direction of the atmosphere pressure sensing surfaces of each pressure sensor.
6. The apparatus as claimed in claim 5 , wherein each pressure sensor comprises an air entrance through which the atmosphere enters, and the normal direction of the atmosphere pressure sensing surface is parallel to the normal direction of the air entrance.
7. The apparatus as claimed in claim 5 , wherein each pressure sensor comprises an air entrance through which the atmosphere enters, and the normal direction of the atmosphere pressure sensing surface is perpendicular to the normal direction of the air entrance.
8. A pressure sensor (or measuring atmosphere pressure, the pressure sensor comprising:
first and second pressure sensing elements configured to obtain first and second data values of atmosphere pressure; and
a processor configured to derive a third data value of atmosphere pressure from the first and second data values of atmosphere pressure;
wherein each pressure sensing element is deformable in response to the atmosphere pressure and comprises an atmosphere pressure sensing surface, and the normal direction of the atmosphere pressure sensing surface of the first pressure sensing element is configured so as to be opposite to the normal direction of the atmosphere pressure sensing surface of the second pressure sensing element.
9. An apparatus for detecting a fall of a user, the apparatus comprising:
a pressure sensor configured to obtain a data value of atmosphere pressure, the pressure sensor comprising a pressure sensing element being deformable in response to the atmosphere pressure; and
a housing configured to house the pressure sensor;
wherein the pressure sensing element comprises an atmosphere pressure sensing surface and the pressure sensor is configured in the housing in a way such that the normal direction of the atmosphere pressure sensing surface is substantially at right angles to the gravity direction when the pressure sensor falls to the ground.
10. The apparatus as claimed in claim 9 wherein the housing comprises a plurality of convex surfaces.
11. The apparatus as claimed in claim 9 wherein the housing comprises six flat sides and one convex surface is formed on four of the six flat sides.
12. The apparatus as claimed in claim 9 , wherein the housing comprises a substantially flat surface and the shape of the housing is substantially flat, and the pressure sensor is configured in the housing in a way such that the normal direction of the atmosphere pressure sensing surface is substantially parallel to the substantially flat surface of the housing.
13. The apparatus as claimed in claim 12 , wherein the pressure sensor comprises an air entrance through which the atmosphere enters, and the normal direction of the atmosphere pressure sensing surface is parallel to the normal direction of the air entrance.
14. The apparatus as claimed in claim 9 wherein the housing comprises an elliptical portion and a flat portion.
15. The apparatus as claimed in claim 14 wherein the normal direction of the atmosphere pressure sensing surface is parallel to the flat portion.
16. A method of detecting a fall of a user, the method comprising:
obtaining first and second data values of atmosphere pressure by first and second pressure sensors; and
deriving a third data value of a atmosphere pressure from the first and second data values of atmosphere pressure by a processor;
wherein the first and second pressure sensors are configured in a way such that preset orientations of the first and second pressure sensors are opposite to each other.
17. The method as claimed in claim 16 , wherein the step of deriving comprises:
deriving the third data value of atmosphere pressure by calculating the average of the first and second data values of atmosphere pressure by the processor.
18. The method as claimed in claim 16 , wherein each pressure sensor comprises a pressure sensing element with an atmosphere pressure sensing surface, and the preset orientation is the normal direction of the atmosphere pressure sensing surface of each pressure sensor.
19. The method as claimed in claim 18 , wherein each pressure sensor comprises an air entrance through which the atmosphere enters, and the normal direction of the atmosphere pressure sensing surface is parallel to the normal direction of the air entrance.
20. A method of measuring the atmosphere pressure, the method comprising:
obtaining first and second data values of atmosphere pressure by first and second pressure sensing elements; and
deriving a third data value of atmosphere pressure from the first and second data values of atmosphere pressure by a processor;
wherein each pressure sensing element comprises an atmosphere pressure sensing surface which is deformable in response to the atmosphere pressure, and the normal direction of the atmosphere pressure sensing surface of the first pressure sensing element is configured so as to be opposite to the normal direction of the atmosphere pressure sensing surface of the second pressure sensing element.