Method and system for measuring energy expenditure and foot incline in individuals

• US 7,921,716 B2
• Filed: 03/20/2009
• Issued: 04/12/2011
• Est. Priority Date: 03/20/2008
• Status: Active Grant

• Current Assignee: University of Utah Research Foundation (State of Utah)
• Original Assignee: University of Utah Research Foundation (State of Utah)
• Inventors: Fehlberg, Mark A., Morris Bamberg, Stacy J.
• Primary Examiner(s): DOWTIN, JEWEL VIRGIE
• Application Number:
  US12/407,978
• Publication Number:
  US 20090235739A1
• Time in Patent Office: 753 Days
• Field of Search: 733/790.5, 731/72, 725/9, 702/160, 455/3.01, 709/231, 600/587, 600/592
• US Class Current: 73/379.05
• CPC Class Codes: A43B 17/00 Insoles for insertion, e.g. footbeds or inlays, for attachment to the shoe after the upper has been joined
• CPC Class Codes: A43B 3/34 with electrical or electronic arrangements
• CPC Class Codes: A43B 7/00 Footwear with health or hygienic arrangements
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/1038 Measuring plantar pressure during gait
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A61B 5/222 combined with detection or measurement of physiological parameters, e.g. heart rate
• CPC Class Codes: A61B 5/4866 Evaluating metabolism A61B5/083 takes precedence
• CPC Class Codes: A61B 5/6807 Footwear
• CPC Class Codes: G01P 13/00 Indicating or recording presence, absence, or direction, of movement electric switches H01H; counting moving objects G06M7/00

Abstract

A method and system for measuring energy expenditure of individuals by measuring force from a plurality of foot-borne force sensitive resistors and calculating incline from a foot-borne tri-axial accelerometer.

Claims

1. A method for analyzing motion of an individual, comprising:

a) affixing at least a tri-axial accelerometer with respect to a user'"'"'s foot;

b) collecting accelerometer data from the tri-axial accelerometer;

c) determining incline during stance phase based on the accelerometer data from the tri-axial accelerometer using an electronic processor;

d) determining stance phase based on the accelerometer data from tri-axial accelerometer using the electronic processor; and

e) determining an energy expenditure of the individual based on the inclination of the shoe with respect to the ground over a period of time using the electronic processor.

2. A method in accordance with claim 1, further comprising:

determining energy expenditure of the individual based on the accelerometer data from the tri-axial accelerometer using the electronic processor.

3. A method in accordance with claim 1, further comprising:

affixing a plurality of force sensitive resistors with respect to the user'"'"'s foot;

collecting force data from the plurality of force sensitive resistors; and

determining stance phase based on the force data from the plurality of force sensitive resistors using the electronic processor.

4. A method in accordance with claim 3, further comprising:

determining an energy expenditure of the individual based on the force applied to the shoe and the inclination of the shoe with respect to the ground over a period of time using the electronic processor.

5. A method in accordance with claim 1, wherein determining stance phase further includes determining a magnitude of acceleration vector utilizing the equation:

|{right arrow over (A)}|=√

{square root over (A_x²+A_y²+A_z²)}

where A_x, A_y and A_z are magnitudes of acceleration measured by the tri-axial accelerometer in x, y and z directions, and A is the magnitude of the acceleration vector; and

wherein the magnitude of total acceleration being substantially equal to 1 g during stance phase.

6. A method in accordance with claim 1, further comprising:

estimating incline utilizing the equation;

7. A method in accordance with claim 1, further comprising:

determining offset between the shoe and the sensor board when the system is initialized and the foot is on level ground utilizing the equation;

8. A method in accordance with claim 1, further comprising:

positioning a toe piece of an insole with at least one force sensitive resistor at a toe of the shoe;

positioning a heel piece of the insole with at least one force sensitive resistor at a heel of the shoe; and

positioning a middle piece of the insole with the tri-axial accelerometer in the shoe between the toe and heel pieces.

9. A method for measuring activity in an individual, comprising:

a) collecting data from a multi-sensor insole disposed in a shoe, including force data from a plurality of force sensitive resistors and accelerometer data from a tri-axial accelerometer;

b) analyzing the data from the sensors of the multi-sensor insole with an electronic processor to determine the energy expenditure of the individual based on the force data and inclination of the shoe with respect to the ground during stance phase over a period of time; and

c) determining stance phase based on the force data from the plurality of force sensitive resistors using the electronic processor.

10. A method in accordance with claim 9, further comprising:

estimating the inclination utilizing the equation;

11. A method in accordance with claim 9, further comprising:

determining offset between the shoe and the sensor board when the system is initialized and the foot is on level ground utilizing the equation;

12. A method in accordance with claim 9, further comprising:

determining stance phase based on the force data and the accelerometer data and utilizing the equations;

|{right arrow over (A)}|=√

{square root over (A_x²+A_y²+A_z²)}

where A_x, A_y and A_z are magnitudes of acceleration measured by the tri-axial accelerometer in x, y and z directions, and A is the magnitude of the acceleration vector; and

wherein the magnitude of total acceleration being substantially equal to 1 g during stance phase.

13. A method in accordance with claim 12, further comprising:

positioning a toe piece of an insole with at least one force sensitive resistor at a toe of the shoe;

positioning a heel piece of the insole with at least one force sensitive resistor at a heel of the shoe; and

positioning a middle piece of the insole with the tri-axial accelerometer in the shoe between the toe and heel pieces.