Method and apparatus for body impact protection
A motion analysis system includes: at least one orientation sensor configured to detect three-dimensional torso motion over time, the at least one orientation sensor including: a multiaxial accelerometer configured to detect acceleration in at least three orthogonal directions, and a gyroscope; and a controller configured to receive data from the at least one orientation sensor, the controller programmed to process the data to: determine at least one of a state and a transition of the torso; identify normal parameters for the determined at least one of the state and transition; and determine whether motion of the torso is outside the normal parameters. The controller is configured to identify, in real-time, the occurrence of a fall in progress of an individual from at least one of a standing state, a standing-to-seated transition, and a seated-to-standing transition.
1. A motion analysis system comprising:
at least one orientation sensor configured to detect three-dimensional torso motion over time, the at least one orientation sensor comprising:
a multiaxial accelerometer configured to detect acceleration in at least three orthogonal directions, and
a gyroscope; and
a controller configured to receive data from the at least one orientation sensor, the controller programmed to process the data to:
determine at least one of a state and a transition of the torso;
identify normal parameters for the determined at least one of the state and transition; and
determine whether motion of the torso is outside the normal parameters
wherein the controller is configured to identify, in real-time, the occurrence of a fall in progress of an individual from at least one of a standing state, a standing-to-seated transition, and a seated-to-standing transition.
2. The motion analysis system of claim 1 , wherein the at least one orientation sensor is further configured to detect pitch, roll, and yaw of the torso.
3. The motion analysis system of claim 1 , wherein the at least one orientation sensor is further configured to detect an acceleration of each of pitch, roll, and yaw of the torso, and a vertical acceleration of the torso referenced to gravity.
4. The motion analysis system of claim 1 , wherein the at least one orientation sensor is further configured to detect a velocity of each of pitch, roll, and yaw of the torso, and a vertical velocity of the torso.
5. The motion analysis system of claim 1 , wherein the at least one orientation sensor is further configured to detect a total acceleration of the torso.
6. The motion analysis system of claim 1 , wherein the at least one orientation sensor is further configured to detect a trajectory of the torso.
7. The motion analysis system of claim 1 , wherein the at least one orientation sensor comprises an inertial measurement unit.
8. The motion analysis system of claim 1 , wherein the at least one orientation sensor further comprises a magnetic field sensor.
9. The motion analysis system of claim 1 , wherein the state of the torso comprises at least one of standing, walking, seated, and recumbent.
10. The motion analysis system of claim 1 , wherein the transition of the torso comprises at least one of standing-to-seated, seated-to-standing, seated-to-recumbent, and recumbent-to-seated.
11. The motion analysis system of claim 1 , wherein the controller is programmed to determine the state of the torso based on a gravity-referenced motion intrinsic to the state, the orientation of the at least one sensor, and a transition of the torso that led to the state.
12. The motion analysis system of claim 1 , wherein the controller is programmed to determine the transition of the torso based on a state from which the transition originates and the three-dimensional torso motion referenced to gravity.
13. The motion analysis system of claim 1 , wherein:
the controller is programmed to identify normal parameters for the state by reference to parameters for normal states that are programmed into the controller, the parameters for normal states being based on experimental, orientation-sensor monitoring of the torso motions of individuals who are standing, walking, seated, and recumbent.
14. The motion analysis system of claim 13 , wherein the controller is programmed to identify normal parameters for the transition by reference to parameters for normal transitions that are programmed into the controller, the parameters for normal transitions being based on experimental, orientation-sensor monitoring of the torso motions of individuals who are transitioning between standing and sitting, sitting and standing, sitting and lying down, and lying down and standing.
15. The motion analysis system of claim 13 , wherein the parameters for normal states or normal transitions are parameters developed by observation of a user of the motion analysis system.
16. The motion analysis system of claim 15 , wherein the observation of the user of the motion analysis system is performed during a training mode.
17. The motion analysis system of claim 1 , wherein the parameters include an attitude of the torso, a three-dimensional trajectory of the torso referenced to gravity, a duration of a nearly weightless state of the torso, and angular rates of the torso along multiple axis during descent of the torso.
18. The motion analysis system of claim 17 , wherein the parameters further include a sequence of motions and total acceleration, including a gravitational reference, and the force and duration of deceleration.
19. The motion analysis system of claim 18 , wherein the controller is further configured to determine whether a force and duration of deceleration of the torso are outside normal parameters for a force and duration of deceleration.
20. The motion analysis system of claim 1 , wherein the controller is further configured to determine that a descending motion of the torso, referenced to gravity, that is greater than one standard deviation beyond one or more of the normal parameters is a fall of an individual.
21. The motion analysis system of claim 1 , wherein the controller is configured to determine whether the motion of the torso is outside the normal parameters based on data obtained from the at least one orientation sensor during a period of between 1 second and 10 minutes.
22. The motion analysis system of claim 1 , wherein the normal parameters are set such that motion of the torso that is outside the normal parameters is indicative of a fall.
23. The motion analysis system of claim 1 , further comprising at least one additional gyroscope.
24. The motion analysis system of claim 1 , wherein the multiaxial accelerometer and the gyroscope are hard wired to the controller.
25. The motion analysis system of claim 1 , wherein the at least one orientation sensor is configured for wireless communication with the controller.
26. The motion analysis system of claim 1 ,
wherein the controller is configured to identify the standing-to-seated transition based at least on (i) a magnitude of an anterior or anterolateral tilt of the torso detected by the at least one orientation sensor, and (ii) a posterior descent of the pelvis measured by the at least one orientation sensor,
wherein the controller is configured to identify the seated-to-standing transition based at least on (i) a magnitude of an anterior or anterolateral tilt of the torso detected by the at least one orientation sensor, and (ii) an anterior ascent of the torso measured by the at least one orientation sensor,
wherein the controller is configured to identify, in real-time, the occurrence of the fall in progress of the individual from a standing state, the standing-to-seated transition, or the seated-to-standing transition, based on at least one of (i) a lateral and downward acceleration exceeding a predetermined threshold, (ii) a cephalad acceleration exceeding a predetermined threshold, and (iii) a backward and downward motion without prior transitional movement of a forward tilt within a predetermined angle range.
27. The motion analysis system of claim 1 , wherein the controller is configured to identify a normal standing-to-seated transition based on statistical conformity within programmed limits with (i) a magnitude and direction of three-dimensional torso tilt, (ii) a three-dimensional trajectory of the torso, (iii) angular rates of the torso in X, Y and Z axes, and (iv) a duration of a nearly-weightless state of the torso.
28. The motion analysis system of claim 1 , wherein the controller is configured to identify the seated-to-standing transition based on statistical conformity within programmed limits with (i) a magnitude and direction of three-dimensional torso tilt, (ii) a three-dimensional trajectory of the torso, (iii) angular rates of the torso in the X, Y and Z axes, and (iv) an upward acceleration of the torso opposed to gravity.
29. The motion analysis system of claim 1 , wherein the controller is configured to identify, in real-time, the occurrence of a fall-in-progress from the standing state, the standing-to-seated transition or the seated-standing transition based on deviations beyond threshold values from at least one of (i) three-dimensional torso tilt, (ii) three-dimensional torso trajectory, (iii) angular rates of the torso in the X, Y and Z axes, and (iv) a duration of a nearly-weightless state of the torso.
30. A motion analysis system comprising:
at least one orientation sensor configured to detect three-dimensional torso motion over time, the at least one orientation sensor comprising:
a multiaxial accelerometer configured to detect acceleration in at least three orthogonal directions, and
a gyroscope; and
a controller configured to receive data from the at least one orientation sensor, the controller programmed to process the data to identify, in real-time, the occurrence of a fall in progress of an individual from at least one of a standing state, a standing-to-seated transition, and a seated-to-standing transition.