Fall detection device and method

A device wearable by a user, the device comprising:

• a processor;
• an acceleration sensor operatively attached to the processor, wherein the acceleration sensor is configured to sense an acceleration vector of the protection device;
• a gyroscope sensor operatively attached to the processor, wherein the gyroscope sensor is configured to sense an angular velocity of the device;
• a distance sensor operatively attached to the processor, wherein said distance sensor is oriented to measure a point-to-point distance between the protection device and a point on the ground;
• wherein the processor is configured to time sample and to input a plurality of respective values over time of:
• the acceleration vector, the angular velocity and the point-to-point distance;
• wherein the processor is configured to determine over time the direction of gravity from the acceleration vector;
• wherein the processor is configured to integrate over time the angular velocity to produce an orientation angle of the protection device relative to the direction of gravity;
• wherein the processor, responsive to the point-to-point distance and the orientational angle, is configured to dctcrminecompute heights over time of the distance sensor from the ground;
• wherein the processor is configured to indicate initiation of a potential fall event by a change in downward acceleration measured by the accelerometer or a rapid decrease in the determined heights of the distance sensor from the ground;
• wherein the processor is configured, responsive to the point-to-point distance and the orientation angle, to compute a height of the distance sensor from the ground before the initiation of the potential fall event a height of the distance sensor from the ground after the initiation of the potential fall event,
• wherein the processor, when a computed height is less than a predetermined threshold height, is configured to determine completion of a fall at a time tf and to compute said height of the distance sensor after the initiation of the potential fall event based on stored results from a measurement recorded at a time during a previously determined time interval prior to the time tf.