Method for Estimating Elevation Changes Traveled by a User

• US 20150127296A1
• Filed: 11/06/2014
• Published: 05/07/2015
• Est. Priority Date: 11/07/2013
• Status: Active Grant

• Current Assignee: Withings S.A.
• Original Assignee: Withings S.A.
• Inventors: Carreel, Eric, Thomas, Rmi
• Granted Patent: US 9,989,360 B2
• Time in Patent Office: Days
• US Class Current: 702/150
• 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 at least one pressure sensor adapted to provide pressure values and a temperature sensor adapted to provide temperature values in order to adjust the pressure values, said pressure sensor being adapted to be held substantially fixed to at least a portion of the body of said user during the implementation of said method, said method comprising:

a)—

an operation of periodically sampling raw pressure values, reading the current raw pressure at a first sampling frequency F1, the raw values being stored in the form of pressure or the corresponding altitude in a first buffer,

b)—

a filtering operation,, based on the raw values stored in the first buffer, to determine filtered values,

c)—

a variance calculation, performed on at least a portion of the filtered values, to determine an inclusion condition for including the elevation changes corresponding to the observed pressure or altitude differences, and

d)—

an elevation change traveled calculation, particularly the positive elevation change, by the user during his/her displacement.

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 2, 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:

e)—

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

if VAR>

S then the inclusion condition is ‘

true’ and

the observed elevation changes are included in the calculation of the elevation change estimate, and

if VAR<

S then the inclusion condition is ‘

false’ and

the observed elevation changes are not included in the calculation of the elevation change estimate.

7. The method for estimating the elevation change traveled by a user according to claim 6, wherein, when the inclusion condition changes from ‘

false’

to ‘

true’

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

8. A device adapted to implement the method according to claim 1.

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