Ultra low power actigraphy based on dynamic threshold
First Claim
1. An activity monitor, comprising:
- an accelerometer adapted to be worn by a user and outputting an activity signal indicative of an activity level of the user;
a circuit in communication with the accelerometer and determining whether the activity signal output from the accelerometer exceeds a threshold; and
a processor configured to be in communication with the accelerometer and the circuit,the processor is adapted to process data samples from the accelerometer in an active mode of the processor, and otherwise reduce power consumption of the activity monitor by not transferring the data samples from the accelerometer to the processor,the circuit triggering the processor to enter the active mode, for a minimum period of time, from a reduced power mode when the activity signal output exceeds the threshold, and the minimum period of time is adjustable based on a determination that the user will remain active within the minimum period of time,the processor, upon entering the active mode, configured to evaluate data samples from the accelerometer during an evaluation period, the evaluation period triggered by the circuit detecting the activity signal exceeding the threshold, and the threshold adaptively adjustable based on sensor input, andthe processor, based on the evaluation, configured to determine the activity level of the user, andthe processor, based on the activity level, configured to determine whether to remain in the active mode or to transition to the reduced power mode.
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Accused Products
Abstract
A processor for an activity monitor for a user has a reduced power mode in which it does not process data samples from an accelerometer. A wake up circuit or logic evaluates an output from the accelerometer and determines whether the output exceeds a threshold, indicating a threshold amount of activity of the user. If the threshold is exceeded, the wake up circuit or logic causes the processor to enter an active mode. The processor evaluates samples of the accelerometer in an evaluation period and decides whether to continue in the active mode or return to the reduced power mode. If the user is deemed to be sufficiently active, the processor continues in the active mode. In another aspect, the threshold can be set based on an activity level of the user before the reduced power mode or sensor data such as ambient light level or skin temperature.
24 Citations
24 Claims
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1. An activity monitor, comprising:
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an accelerometer adapted to be worn by a user and outputting an activity signal indicative of an activity level of the user; a circuit in communication with the accelerometer and determining whether the activity signal output from the accelerometer exceeds a threshold; and a processor configured to be in communication with the accelerometer and the circuit, the processor is adapted to process data samples from the accelerometer in an active mode of the processor, and otherwise reduce power consumption of the activity monitor by not transferring the data samples from the accelerometer to the processor, the circuit triggering the processor to enter the active mode, for a minimum period of time, from a reduced power mode when the activity signal output exceeds the threshold, and the minimum period of time is adjustable based on a determination that the user will remain active within the minimum period of time, the processor, upon entering the active mode, configured to evaluate data samples from the accelerometer during an evaluation period, the evaluation period triggered by the circuit detecting the activity signal exceeding the threshold, and the threshold adaptively adjustable based on sensor input, and the processor, based on the evaluation, configured to determine the activity level of the user, and the processor, based on the activity level, configured to determine whether to remain in the active mode or to transition to the reduced power mode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for determining activity of a user monitored by an activity monitor, comprising:
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outputting signals from an accelerometer to a wake up circuit, the accelerometer adapted to be worn by the user; determining if the signals output from the accelerometer exceed a threshold using the wake up circuit; when the output signals exceed the threshold, evaluating data samples from the accelerometer during an evaluation period to analyze an activity level of the user using a processor, the samples from the accelerometer are not evaluated by the wake up circuit to analyze the activity level of the user; and determining whether to continue to evaluate the samples from the accelerometer based on the activity level of the user using the processor after a minimum period of time calculated from an end of the evaluation period, such that when the output signals fail to exceed the threshold, reducing power consumption of the activity monitor by not transferring the data samples from the accelerometer to the processor. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A non-transitory computer-readable storage apparatus having computer-readable program code embodied thereon for programming a processor to perform a method, the method comprising:
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the program code configured to obtain an output signal from an accelerometer of an activity monitor adapted to be worn by a user; the program code configured to determine if the output signal exceeds a threshold, the output signal analyzed by a wake up component of the activity monitor; and if the output signal exceeds the threshold, the program code configured to process data samples of the accelerometer using an active mode of a processor; the program code configured to receive sensor data from a sensor of the activity monitor adapted to be worn by the user; and based on the processing of the data samples and the sensor data, the program code configured to determine whether to continue the active mode of the processor after a minimum period of time calculated from a start of the active mode, wherein the threshold is adjusted based on factors representative of a type of the sensor and the activity of the user to variably trigger the active mode of the processor. - View Dependent Claims (18, 19, 20)
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21. An activity monitor, comprising:
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one or more sensors, including one of the sensors as an accelerometer, outputting an activity signal, the accelerometer is adapted to be worn by a user; and a processor comprising activity analysis logic and wake up logic, the processor is configured to be in communication with the accelerometer, the wake up logic determines whether the activity signal output from the accelerometer exceeds a variable threshold, the activity analysis logic is adapted to process data samples from the accelerometer in an active mode of the processor, the wake up logic causes the processor to enter the active mode from a reduced power mode based on whether the activity signal exceeds the variable threshold, the variable threshold being set based on variables representative of an activity level of the user and a type of the one or more sensors employed for measuring the activity level, the processor, upon entering the active mode, is configured to activate the activity analysis logic to evaluate the data samples from the accelerometer during an evaluation period, and based on the evaluation, determine the activity level of the user, and the processor, based on the activity level, is configured to determine whether to remain in the active mode or to transition to the reduced power mode. - View Dependent Claims (22, 23, 24)
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Specification