Ambulatory system for measuring and monitoring physical activity and risk of falling and for automatic fall detection

A fall detection monitoring system comprising:

• a sensor adapted to be attached to an upper part of a body of a person, the sensor comprising a movement detection component adapted to generate signals in response to a movement of the body;
• and
• one or more processor circuits programmed to:
• identify one or more peaks in the signals from the movement detection component;
• and
• for at least one of the one or more identified peaks,
• process the signals identify a non-fall activity performed by the person in a time period prior to a time period corresponding to the peak;
• in response to identifying that the non-fall activity preceding the peak was a first type of non-fall activity, set one or more fall thresholds to a first set of one or more values;
• in response to identifying that the non-fall activity preceding the peak was a second type of non-fall activity, set the one or more fall thresholds to a second set of one or more values;
• and
• identify the peak as indicative of a fall event if the peak meets the one or more fall thresholds.

A method of monitoring body movement using signals from a sensor adapted to be attached to an upper part of a body of a person, the sensor comprising an accelerometer component adapted to generate signals in response to movement of the body, the signals comprising a frontal acceleration signal and a vertical acceleration signal, the method comprising:

• filtering, by one or more processor circuits, at least a portion of the signals generated by the accelerometer component to obtain a first set of filtered signals;
• determining, by said one or more processor circuits, an initial estimated postural transition duration for a first postural transition based on one or more peaks in the first set of filtered signals and for a first time window;
• applying, by said one or more processor circuits, one or more additional filters to a segment of the signals generated by the accelerometer component to obtain a second set of filtered signals, the segment corresponding to only a second time window that is narrower than the first time window and that is selected based at least in part on a timing corresponding to the initial estimated postural transition duration for the first postural transition;
• determining, by said one or more processor circuits, a revised estimated postural transition duration that is more accurate than the initial estimated postural transition duration for the first postural transition based on a location of one or more peaks in the second set of filtered signals;
• and
• deriving, by said one or more processor circuits, information related to the first postural transition using the revised estimated postural transition duration and the second set of filtered signals, the information including identification of at least one of a time of occurrence, a duration, and a type of the first postural transition.

A method of detecting fall events using signals from a sensor adapted to be attached to an upper part of a body of a person, the sensor comprising a movement detection component adapted to generate signals in response to a movement of the body, the method comprising:

• identifying, by one or more processor circuits, one or more peaks in the signals generated by the movement detection component;
• and
• for at least one of the one or more identified peaks,
• processing the signals to identify a non-fall activity performed by the person in a time period prior to a time period corresponding to the peak;
• if the non-fall activity preceding the peak was identified as a first type of non-fall activity, setting one or more fall thresholds to a first set of one or more values;
• if the non-fall activity preceding the peak was identified as a second type of non-fall activity, setting the one or more fall thresholds to a second set of one or more values;
• and
• identifying the peak as indicative of a fall event if the peak meets the one or more fall thresholds.