Method for estimating elevation changes traveled by a user

• US 9,989,360 B2
• Filed: 11/06/2014
• Issued: 06/05/2018
• Est. Priority Date: 11/07/2013
• Status: Active Grant

• Current Assignee: Withings S.A.
• Original Assignee: Withings S.A.
• Inventors: Thomas, Rmi, Carreel, Eric
• Primary Examiner(s): Raymond, Edward
• Application Number:
  US14/534,977
• Publication Number:
  US 20150127296A1
• Time in Patent Office: 1,307 Days
• Field of Search: 702150, 702182-185
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A61B 5/6801 specially adapted to be attached to or worn on the body surface
• CPC Class Codes: G01C 22/006 Pedometers
• CPC Class Codes: G01C 5/00 Measuring height; Measuring distances transverse to line of sight; Levelling between separated points; Surveyors' levels G01C3/20, G01C3/30 take precedence
• CPC Class Codes: G01C 5/06 by using barometric means

Abstract

A method for estimating the elevation change traveled by a user, said method using a pressure sensor and a temperature sensor, the pressure sensor being adapted to be held fixed to the user, the method comprising:

• • a)—an operation of periodically sampling raw pressure values, reading the current raw pressure at a first sampling frequency, the raw values being stored in the form of pressure or the corresponding altitude in a first buffer (B1),
  • b)—a filtering operation based on the raw values stored in the first buffer, in order to determine filtered values,
  • c)—a variance calculation, performed on at least a portion of the filtered values, in order to determine a condition for including the elevation changes corresponding to the observed pressure or altitude differences.

Claims

1. A method for estimating the elevation change traveled by a user, said method using a device comprising at least one pressure sensor configured to provide pressure values, an accelerometer configured to detect accelerations experienced by the device and a temperature sensor configured to provide temperature values in order to adjust the pressure values, said method comprising:

a)—

periodically sampling the pressure values, reading the current pressure at a first sampling frequency F1, and storing the pressure values in the form of pressure or the corresponding altitude in a first buffer,

b)—

filtering the pressure values stored in the first buffer, in order to determine filtered values,

c)—

calculating a variance, on at least a portion of the filtered values, in order to determine a condition for including elevation changes corresponding to observed differences in the stored pressure or altitude values,

d)—

calculating an elevation change traveled for the user, during his/her displacement,

e)—

making a meter of positive elevation gains, based on the elevation change traveled calculation, and

f)—

displaying the meter on a display of the device or communicating the meter to a smartphone.

2. The method according to claim 1, wherein the filtering operation is performed at the rate of the first sampling frequency F1.

3. The method according to claim 1, wherein the variance calculation is performed at a second frequency F2 that is less than or equal to the first sampling frequency F1.

4. The method according to claim 3, wherein the first frequency F1 is a multiple of the second frequency F2, meaning F1=k F2.

5. The method according to claim 1, wherein the variance calculation is performed on P subsampled filtered values stored in a second buffer.

6. The method according to claim 1, further comprising:

comparing the result of the variance calculation VAR to a predetermined threshold value S, and

if VAR>

S then the condition for including is ‘

true’ and

the observed elevation changes are included in the elevation change traveled calculation, and

if VAR<

S then the condition for including is ‘

false’ and

the observed elevation changes are not included in the elevation change traveled calculation.

7. The method according to claim 6, wherein, when the condition for including changes from ‘

false’

to ‘

true’

, the included observed elevation change is based on the oldest value stored in the second buffer.

8. A device configured to estimate an elevation change traveled by a user, said device comprising at least one pressure sensor configured to provide pressure values, an accelerometer configured to detect accelerations experienced by the device and a temperature sensor configured to provide temperature values in order to adjust the pressure values, said device further configured to:

a)—

perform periodically sampling the pressure values, read the current pressure at a first sampling frequency F1, and store the pressure values in the form of pressure or the corresponding altitude in a first buffer,

b)—

perform a filtering operation on the pressure values stored in the first buffer, in order to determine filtered values,

c)—

perform a variance calculation, on at least a portion of the filtered values, in order to determine a condition for including elevation changes corresponding to observed differences in the stored pressure or altitude values,

d)—

perform an elevation change traveled calculation for the user, during his/her displacement,

e)—

make a meter of positive elevation gains, based on the elevation change traveled calculation, and

f)—

display the meter on a display of the device or to communicate the meter to a smartphone.

9. The device according to claim 8, wherein the device is in the form of a personal activity monitoring unit.

10. The device according to claim 8, further configured to perform the filtering operation at the rate of the first sampling frequency F1.

11. The device according to claim 8, further configured to perform the variance calculation at a second frequency F2 that is less than or equal to the first sampling frequency F1.

12. The device according to claim 11, wherein the first frequency F1 is a multiple of the second frequency F2, meaning F1=k F2.

13. The device according to claim 8, further configured to perform the variance calculation on P subsampled filtered values stored in a second buffer.

14. The device according to claim 8, further configured to:

compare the result of the variance calculation VAR to a predetermined threshold value S,

if VAR>

S then the condition for including is ‘

true’ and

the observed elevation changes are included in the elevation change traveled calculation,

if VAR<

S then the condition for including is ‘

false’ and

the observed elevation changes are not included in the elevation change traveled calculation.

15. The device according to claim 14, wherein, when the condition for including changes from ‘

false’

to ‘

true’

, the included observed elevation change is based on the oldest value stored in the second buffer.