POWER EFFICIENT SYSTEM AND METHOD FOR MEASURING PHYSICAL ACTIVITY IN RESOURCE CONSTRAINED DEVICES

• US 20150057967A1
• Filed: 08/26/2013
• Published: 02/26/2015
• Est. Priority Date: 08/26/2013
• Status: Active Grant

• Current Assignee: Everyfit Incorporated
• Original Assignee: Everyfit Incorporated
• Inventors: Albinali, Fahd Khalaf
• Granted Patent: US 9,554,747 B2
• Time in Patent Office: Days
• US Class Current: 702/150
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/002 Monitoring the patient using a local or closed circuit, e.g. in a room or building A61B5/0017 takes precedence
• CPC Class Codes: A61B 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A61B 5/681 Wristwatch-type devices

Abstract

The systems and methods described herein relate to the power efficient measurement of physical activity with a wearable sensor. More particularly, the systems and methods described herein enable the continuous activity tracking without compromising battery life. In some implementations, the wearable sensor detects movement and enters predefined power states responsive to the type of movement detected.

Claims

1. A method for efficiently measuring physical activity with a wearable device, the method comprising:

waking a wearable device from a low power state, the wearable device comprising a motion sensor;

obtaining, by the wearable device, one or more data points of a motion signal from the motion sensor at a first point in time with a first frequency and;

determining by the wearable device if the one or more data points are above a first threshold; and

obtaining, by the wearable device, for a predetermined amount of time and at a second frequency one or more additional data points of the motion signal responsive to the one or more data points being above the first threshold.

2. The method of claim 1, wherein obtaining the one or more data points further comprises:

obtaining only one data point from the motion signal; and

determining an orientation of the wearable device at the one data point.

3. The method of claim 1, wherein obtaining the one or more data points further comprises:

obtaining a first data point from the motion signal;

pausing for a second predetermined amount of time; and

obtaining a second data point from the motion signal.

4. The method of claim 3, wherein determining if the one or more data points are above the first threshold further comprises determining if each of the first data point and the second data point are above the first threshold.

5. The method of claim 1, wherein determining if the one or more data points are above the first threshold further comprises:

determining a number of data points in the one or more data points that are above the first threshold; and

determining if the number is greater than a second threshold.

6. The method of claim 1, wherein determining if the one or more data points are above the first threshold further comprises determining if a consecutive subset of data points within the one or more data points are above the first threshold.

7. The method of claim 1, wherein determining if the one or more data points are above the first threshold further comprises determining if the absolute value of a difference between the one or more data points and a previous obtained data point is above the first threshold.

8. The method of claim 1, further comprising switching to the low power state at the end of the predetermined amount of time.

9. The method of claim 1, further comprising switching back to sampling the motion signal at the first frequency at the end of the predetermined amount of time.

10. The method of claim 1, further comprising:

comparing a subset of samples sampled at the second frequency to a second threshold; and

switching to the low power state if a predetermined number of the samples in the subset of samples are not greater than the second threshold.

11. The method of claim 1, wherein the second frequency is greater than the first frequency.

12. A wearable device comprising:

a processor, coupled to a motion sensor, configured to;

wake from a low power state;

obtain one or more data points of a motion signal of the motion sensor at a first point in time at a first frequency;

determine if the one or more data points are above a first threshold; and

obtain for a predetermined amount of time and at a second frequency one or more additional data points of the motion signal responsive to the one or more data points being above the first threshold.

13. The wearable device of claim 12, wherein the processor is further configured to:

obtain only one data point from the motion signal; and

determine an orientation of the wearable device at the one data point.

14. The wearable device of claim 12, wherein the processor is further configured to:

obtain a first data point from the motion signal;

pause for a second predetermined amount of time; and

obtain a second data point from the motion signal.

15. The wearable device of claim 13, wherein the processor is further configured to determine if the one or more data points are above the first threshold by determining if each of the first data point and the second data point are above the first threshold.

16. The wearable device of claim 12, wherein the processor is further configured to:

determine a number of data points in the one or more data points that are above the first threshold; and

determine if the number is greater than a second threshold.

17. The wearable device of claim 12, wherein the processor is further configured to determine if the one or more data points are above the first threshold by determining if a consecutive subset of data points within the one or more data points are above the first threshold.

18. The wearable device of claim 12, wherein the processor is further configured to switch to the low power state at the end of the predetermined amount of time.

19. The wearable device of claim 12, wherein the processor is further configured to switch back to sampling the motion signal at the first frequency at the end of the predetermined amount of time.

20. The wearable device of claim 12, wherein the processor is further configured to:

compare a subset of samples sampled at the second frequency to a second threshold; and

switch to the low power state if a predetermined number of the samples in the subset of samples are not greater than the second threshold.

21. The wearable device of claim 12, wherein the second frequency is greater than the first sampling frequency.