Method of enhancing the detectability of a height change with an air pressure sensor and a sensor unit for determining a height change
AssigneeKoninklijke Philips N.V.
InventorWarner Rudolph Theophile Ten Kate
Life of this patent
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Abstract
A sensor unit (2) comprising a pressure sensor (9) is worn by a person. A fall of the person causes a height change as well an orientation change of the pressure sensor. To enlarge the detectability of the fall the air pressure is positioned such that in a pre-fall condition the contribution of an error to the sensor's measurement is maximal. This error is caused by gravity acting on the membrane of the sensor.
Claims15
A method of enhancing the detectability of a height change with an air pressure sensor (9), the air pressure sensor providing a height measurement, the height measurement including a measurement error depending on the orientation of the pressure sensor relative to the direction of gravity, the air pressure sensor being included in a sensor unit (2), the sensor unit being attachable to a person (4), the method comprising the steps of
- determining a preferred orientation of the pressure sensor relative to the direction of gravity (5) in which it provides a largest height measurement;
- determining a reference orientation of the sensor unit relative to the direction of gravity wherein said reference orientation corresponds to the orientation of the sensor unit when attached to the person while the person has a predetermined posture;
- determining a relative orientation of the pressure sensor, the relative orientation corresponding to the orientation of the pressure sensor relative to the orientation of the sensor unit wherein the pressure sensor has the preferred orientation while the sensor unit has the reference orientation;
- mounting the pressure sensor in the relative orientation relative to the orientation of the sensor unit.
Dependencies are inferred from the claim text.