System and method for determining a measure of the physical activity of an object

• US 20030074157A1
• Filed: 10/08/2002
• Published: 04/17/2003
• Est. Priority Date: 10/11/2001
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Goris, Annelies Heleen Carolien, Westerterp, Klaas Roelof, De Jongh, Frits Tobi, Van Herk, Johannes Johanna
• Granted Patent: US 6,810,349 B2
• Time in Patent Office: Days
• US Class Current: 702/141
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A63B 2220/40 Acceleration
• CPC Class Codes: A63B 2230/62 posture
• CPC Class Codes: G01P 15/00 Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
• CPC Class Codes: G16H 20/30 relating to physical therapies or activities, e.g. physiotherapy, acupressure or exercising
• CPC Class Codes: G16H 40/67 for remote operation

Abstract

The invention concerns a system and a method for calculating the physical activity level (PAL) as an objective measure of the physical activity of an object over a certain period of time. The system (1) comprises an activity monitor (2) having three orthogonally mounted accelerometers (4, 5 and 6) for measuring the acceleration of the object, data processing means (7) and memory means (8). The activity monitor (2) further comprises communication means (12) for communicating with calculating means (3) for calculating the PAL. According to the claimed method the calculating means use the following algorithm:

PAL=factor 1+factor 2*(variable 1)^{factor 3}+factor 4*(variable 2)^{factor 5}+ . . . +factor(2n)*(variable n)^factor(2n+1).

Herein are variable 1 through variable n related to the object and/or the system and are factor 1 through factor 2n+1 to be determined by validation of the system.

Claims

1. System (1) for determining a measure of the physical activity of an object over a certain period of time, said system comprising measurement means (4,5,6) for measuring data relating to movement of the object, data processing means (7) for processing the measured data and memory means (8) for storing the processed data, characterized in that, the system further comprises calculating means (3) for calculating the physical activity level of the object.

2. System according to claim 1, wherein the calculating means are arranged to calculate the physical activity level of the object based on the following algorithm:

PAL=factor 1+factor 2*(variable

     1)^{factor 3}+factor 4*(variable

     2)^{factor 5}+ . . . +factor(2n)*(variable n)^factor(2n+1)

wherein

PAL=physical activity level of the object;

Variable 1 through variable n=variables related to the object and/or the system; and

Factor 1 through factor 2n+1=factors to be determined by validation of the system.

3. System according to claim 2, wherein the object is a living subject and the variables related to the subject comprise body mass and/or sleep time and/or age and/or length and/or sex.

4. System according to claim 2 or 3, wherein the variables related to the system comprise wear time of the measurement means and/or output of the measurement means, data processing means or memory means.

5. System according to one or more of the preceding claims, wherein the object is a living subject and the calculating means are arranged to calculate the physical activity level of the subject based on the following algorithm:

PAL=a+b*(output)^c+d*(body mass)^e+f*(sleep time)^g+h*(wear time)^I

6. System according to one or more of the preceding claims, wherein, the object is a living subject and the calculating means are arranged to calculate the physical activity level of the subject based on the following algorithm:

PAL=a+b*(output)^c+d*(body mass)^e+f*(sleep time)^g+h*(wear time)^I+j*(age)^k+l*(length)^m+n*(sex)^o

7. System according to one or more of the preceding claims, wherein the measurement means comprise three orthogonally mounted accelerometers for measuring the acceleration of the object.

8. System according to claim 7, wherein the accelerometers comprise piezoelectric material.

9. System according to claim 8, wherein the piezo-electric material is uni-axial.

10. System according to claim 8 or 9, wherein the piezo-electric material is serial bimorph.

11. System according to claim one or more of the preceding claims 7 through 10, wherein the accelerometers have a strip form and are fixed at one end thereof.

12. System according to claim one or more of the preceding claims, comprising an activity monitor (2) in which the measurement means, data processing means and memory means are incorporated, which activity monitor further comprises communication means (12) for communicating with the calculating means.

13. System according to one or more of the preceding claims, wherein the calculating means comprise a computer.

14. Activity monitor described as part of the system according to one or more of the preceding claims.

19. Method according to one or more of the preceding claims, wherein the object is a living subject and the step of calculating the physical activity level of the subject is based on the following algorithm:

PAL=a+b*(output)^c+d*(body mass)^e+f*(sleep time)^g+h*(wear time)^I

20. Method according one or more of the preceding claims, wherein the object is a living subject and the step of calculating the physical activity level of the subject is based on the following algorithm:

PAL=a+b*(output)^c+d*(body mass)^e+f*(sleep time)^g+h*(wear time)^I+j*(age)^k+l*(length)^m+n*(sex)^o

21. Computer program to carry out one or more of the steps of the method according to one or more of the preceding claims.

15. A method for determining a measure of the physical activity of an object over a certain period of time comprising the steps of:

a) measuring data relating to movement of the object;

b) processing the measured data;

c) storing the processed data;

the method being characterized in that it further comprises the step of;

a) calculating the physical activity level of the object.

16. Method according to claim 15, wherein the step of calculating the physical activity level of the object is based on the following algorithm:

PAL=factor 1+factor 2*(variable

     1)^{factor 3}+factor 4*(variable

     2)^{factor 5}+ . . . +factor(2n)*(variable n)^factor(2n+1)

wherein

PAL=physical activity level of the object;

Variable 1 through variable n=variables related to the object and/or the system; and

Factor 1 through factor 2n+1=factors to be determined by validation of the system.

17. Method according to claim 16, wherein the object is a living subject and the variables related to the subject comprise body mass and/or sleep time and/or age and/or length and/or sex.

18. Method according to claim 15 or 16, wherein the variables related to the system comprise wear time of the measurement means and/or output of the measurement means, data processing means or memory means.