FALL DETECTING DEVICE AND FALL DETECTING METHOD

• US 20110218460A1
• Filed: 03/08/2011
• Published: 09/08/2011
• Est. Priority Date: 03/08/2010
• Status: Abandoned Application

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Masuzawa, Toshihiro
• Application Number:
  US13/043,381
• Publication Number:
  US 20110218460A1
• Time in Patent Office: Days
• US Class Current: 600/595
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/1117 Fall detection
• CPC Class Codes: G01C 9/06 Electric or photoelectric indication or reading means
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G08B 21/043 detecting an emergency event, e.g. a fall
• CPC Class Codes: G08B 21/0446 worn on the body to detect changes of posture, e.g. a fall, inclination, acceleration, gait

Abstract

A fall detecting device includes: a detector unit that includes a plurality of tilt sensors each including a pair of electrodes disposed to oppose each other with the positional relationship therebetween being fixed and a conductor capable of freely moving between the pair of electrodes and changing an electrical-connection state between the pair of electrodes by means of the movement of the conductor resulting from a variation in posture of the pair of electrodes, wherein the plurality of tilt sensors are arranged so that directions in which the pairs of electrodes are opposed to each other are perpendicular to each other; a multivalued data output unit that acquires the electrical-connection states between the pair of electrodes of the plurality of tilt sensors and converts the acquired electrical-connection state into multivalued data on the basis of the ratios of the electrical-connection states in a predetermined first period.

Claims

1. A fall detecting device comprising:

a detector unit that includes a plurality of tilt sensors each including a pair of electrodes disposed to oppose each other with the positional relationship therebetween being fixed and a conductor capable of freely moving between the pair of electrodes and changing an electrical-connection state between the pair of electrodes by means of the movement of the conductor resulting from a variation in posture of the pair of electrodes, wherein the plurality of tilt sensors are arranged so that directions in which the pairs of electrodes are opposed to each other are perpendicular to each other;

a multivalued data output unit that acquires the electrical-connection states between the pair of electrodes of the plurality of tilt sensors and converts the acquired electrical-connection state into multivalued data on the basis of the ratios of the electrical-connection states in a predetermined first period; and

a fall determining unit that determines the occurrence of a fall when a moving average value of the multivalued data of the plurality of tilt sensors in a second period is equal to or greater than a first threshold value, wherein the second period is an integral multiple of the first period.

2. The fall detecting device according to claim 1, wherein the fall determining unit determines the occurrence of a fall when a period from a first time point to a second time point is equal to or less than a predetermined third period, where the first time point is when the moving average value of the multivalued data of the plurality of tilt sensors in the second period is equal to or greater than the first threshold value and the second time point is when the moving average value of the multivalued data in the second period of the tilt sensor in which the pair of electrodes is disposed to be opposed to the vertical direction before the variation in posture is equal to or less than a second threshold value.

3. The fall detecting device according to claim 1, wherein each tilt sensor includes the pair of electrodes whose hemispherical concave faces are opposed to each other and the conductor having a spherical shape and the conductor moves in a spherical space formed by the hemispherical concave faces of the pair of electrodes due to the variation in posture of the pair of electrodes.

4. A fall detecting method comprising:

arranging a plurality of tilt sensors each including a pair of electrodes disposed to oppose each other with the positional relationship therebetween being fixed and a conductor capable of freely moving between the pair of electrodes and changing an electrical-connection state between the pair of electrodes by means of the movement of the conductor resulting from a variation in posture of the pair of electrodes so that directions in which the pairs of electrodes are opposed to each other are perpendicular to each other, acquiring the electrical-connection states between the pair of electrodes of the plurality of tilt sensors, and converting the acquired electrical-connection state into multivalued data on the basis of the ratios of the electrical-connection states in a predetermined first period; and

determining the occurrence of a fall when a moving average value of the multivalued data of the plurality of tilt sensors in a second period is equal to or greater than a first threshold value, wherein the second period is an integral multiple of the first period.

5. The fall detecting method according to claim 4, wherein the occurrence of a fall is determined when a period from a first time point to a second time point is equal to or less than a predetermined third period is determined, where the first time point is when the moving average value of the multivalued data of the plurality of tilt sensors in the second period is equal to or greater than the first threshold value and the second time point is when the moving average value of the multivalued data in the second period of the tilt sensor in which the pair of electrodes is disposed to be opposed to the vertical direction before the variation in posture is equal to or less than a second threshold value.