Stride measuring apparatus

• US 20050039541A1
• Filed: 07/27/2004
• Published: 02/24/2005
• Est. Priority Date: 07/28/2003
• Status: Active Grant

• Current Assignee: Hamamatsu Photonics KK
• Original Assignee: Hamamatsu Photonics KK
• Inventors: Kurono, Takehiro
• Granted Patent: US 7,231,834 B2
• Time in Patent Office: Days
• US Class Current: 73/800
• CPC Class Codes: A61B 5/1038 Measuring plantar pressure during gait
• CPC Class Codes: A63B 22/0235 driven by a motor
• CPC Class Codes: A63B 2220/17 Counting, e.g. counting periodical movements, revolutions or cycles, or including further data processing to determine distances or speed
• CPC Class Codes: G01S 17/50 Systems of measurement based on relative movement of target

Abstract

In a stride measuring apparatus, a signal wave emitter and a signal wave detector are opposed to each other in a direction intersecting with a predetermined direction in which the running surface is driven. The signal wave emitter emits a light beam. The signal wave detector outputs an ON signal when receiving the light beam, and outputs an OFF signal when the light beam is intercepted. A detector part calculates a moving speed on the basis of a difference between a fall time and a rise time of one OFF signal out of two OFF signals outputted in succession from the signal wave detector, and a foot size of a subject. The detector part calculates a difference between output times of the two OFF signals (stride time) and calculates a stride on the basis of a product of the moving speed and the stride time.

Claims

1. A stride measuring apparatus comprising:

a belt having a running surface for a subject to run or walk, the belt being driven in a predetermined direction;

signal wave emitting means placed at a position along an edge part of the running surface and configured to emit a signal wave in a direction intersecting with the predetermined direction and at a predetermined height above the running surface;

signal wave detecting means placed at an edge part of the running surface and configured to receive the signal wave emitted by the signal wave emitting means and to output a first signal when a foot of the subject passes across the signal wave, and a second signal when no foot of the subject passes across the signal wave;

moving speed calculating means for calculating a moving time based on a calculation of a difference between a rise time and a fall time of one first signal out of two first signals outputted in succession from the signal wave detecting means, and for calculating a moving speed of the subject on the basis of a calculation of a quotient between a size of the foot of the subject and the moving time;

stride time calculating means for calculating a stride time based on a calculation of a difference between output times of said two first signals; and

stride calculating means for calculating a stride of the subject, based on a calculation of a product between the stride time calculated by the stride time calculating means and the moving speed calculated by the moving speed calculating means.

2. The stride measuring apparatus according to claim 1, further comprising:

second signal wave emitting means placed at a position along an edge part of the running surface and configured to emit a second signal wave in a direction intersecting with the predetermined direction and at a predetermined height above the running surface so as to be inclined at a predetermined angle relative to the emission direction of the signal wave;

second signal wave detecting means placed at a position along an edge part of the running surface and configured to receive the second signal wave emitted by the second signal wave emitting means and to output a first signal when a foot of the subject passes across the second signal wave, and a second signal when no foot of the subject passes across the second signal wave; and

left/right determining means for determining whether the stride calculated by the stride calculating means is a stride of the left foot or a stride of the right foot of the subject, based on a comparison of a time difference between first signals respectively outputted from the signal wave detecting means and from the second signal wave detecting means, with a time difference between first signals respectively outputted in succession from the signal wave detecting means and from the second signal wave detecting means.

3. The stride measuring apparatus according to claim 1, wherein the signal wave emitting means is placed at a position along one edge part of the running surface, and

wherein the signal wave detecting means is placed at a position along another edge part of the running surface and opposite the signal wave emitting means and is configured to output the first signal when the signal wave from the signal wave emitting means is intercepted, and to output the second signal when the signal wave from the signal wave emitting means is detected.

4. The stride measuring apparatus according to claim 1, wherein the signal wave emitting means is placed at a position along one edge part of the running surface, and

wherein the signal wave detecting means is placed at a position along said one edge part of the running surface so as to detect the signal wave emitted from the signal wave emitting means and reflected from a foot of the subject, and is configured to output the first signal when the signal wave is detected, and to output the second signal when the signal wave is not detected.

5. The stride measuring apparatus according to claim 1, further comprising moving time removing means for removing the moving time calculated by the moving speed calculating means, when the moving time calculated by the moving speed calculating means is determined to be shorter, based on a comparison according to a predetermined rule with a moving time calculated at a different time by the moving speed calculating means.

6. A stride measuring apparatus comprising:

a belt having a running surface for a subject to run or walk, the belt being driven in a predetermined direction;

first signal wave emitting means placed at a position along an edge part of the running surface and configured to emit a first signal wave in a direction intersecting with the predetermined direction and at a predetermined height above the running surface;

second signal wave emitting means placed a predetermined distance apart from the first signal wave emitting means in the predetermined direction and configured to emit a second signal wave in a direction intersecting with the predetermined direction and at a predetermined height above the running surface;

first signal wave detecting means placed at an edge part of the running surface and configured to receive the first signal wave emitted by the first signal wave emitting means and to output a first signal when a foot of the subject passes across the first signal wave, and a second signal when no foot of the subject passes across the first signal wave;

second signal wave detecting means placed at an edge part of the running surface and configured to receive the second signal wave emitted by the second signal wave emitting means and to output a first signal when a foot of the subject passes across the second signal wave, and a second signal when no foot of the subject passes across the second signal wave;

moving speed calculating means for calculating a moving time based on a calculation of a difference between an output time of a first signal outputted from the first signal wave detecting means and an output time of a first signal outputted subsequently thereto from the second signal wave detecting means, and for calculating a moving speed of the subject on the basis of a calculation of a quotient between the predetermined distance and the moving time;

stride time calculating means for calculating a stride time based on a calculation of a difference between output times of two first signals outputted in succession from one of the first and second signal wave detecting means; and

stride calculating means for calculating a stride of the subject, based on a calculation of a product between the stride time calculated by the stride time calculating means and the moving speed calculated by the moving speed calculating means.

7. The stride measuring apparatus according to claim 6, further comprising:

third signal wave emitting means placed at a position along an edge part of the running surface and configured to emit a third signal wave in a direction intersecting with the predetermined direction and at a predetermined height above the running surface so as to be inclined at a predetermined angle relative to the emission direction of the first and second signal waves;

third signal wave detecting means placed at an edge part of the running surface and configured to receive the third signal wave emitted by the third signal wave emitting means and to output a first signal when a foot of the subject passes across the third signal wave, and a second signal when no foot of the subject passes across the third signal wave; and

left/right determining means for determining whether the stride calculated by the stride calculating means is a stride of the left foot or a stride of the right foot of the subject, based on a comparison of a time difference between output times of first signals respectively outputted from one of the first and second signal wave detecting means and from the third signal wave detecting means, with a time difference between output times of first signals respectively outputted in succession from said one signal wave detecting means and from the third signal wave detecting means.

8. The stride measuring apparatus according to claim 6, wherein the first and second signal wave emitting means are placed at positions along one edge part of the running surface,

wherein the first signal wave detecting means is placed at a position along another edge part of the running surface and opposite the first signal wave emitting means, and is configured to output the first signal when the first signal wave from the first signal wave emitting means is intercepted, and to output the second signal when the signal wave from the first signal wave emitting means is detected, and

wherein the second signal wave detecting means is placed at a position along the other edge part of the running surface and opposite the second signal wave emitting means, and is configured to output the first signal when the second signal wave from the second signal wave emitting means is intercepted, and to output the second signal when the signal wave from the second signal wave emitting means is detected.

9. The stride measuring apparatus according to claim 6, wherein the first and second signal wave emitting means are placed at positions along one edge part of the running surface,

wherein the first signal wave detecting means is placed at a position along one edge part of the running surface so as to detect the first signal wave emitted from the first signal wave emitting means and reflected from a foot of the subject, and is configured to output the first signal when the first signal wave is detected, and to output the second signal when the first signal wave is not detected, and

wherein the second signal wave detecting means is placed at a position along one edge part of the running surface so as to detect the second signal wave emitted from the second signal wave emitting means and reflected from a foot of the subject, and is configured to output the first signal when the second signal wave is detected, and to output the second signal when the second signal wave is not detected.

10. The stride measuring apparatus according to claim 6, wherein the moving speed calculating means calculates as the moving speed an average of a first moving speed calculated based on a rise time of a first signal outputted from the first signal wave detecting means and a rise time of a first signal outputted subsequently thereto from the second signal wave detecting means and a second moving speed calculated based on fall times of the first signals.

11. The stride measuring apparatus according to claim 6, further comprising moving time removing means for removing the moving time calculated by the moving speed calculating means, when the moving time calculated by the moving speed calculating means is determined to be shorter, based on a comparison according to a predetermined rule with a moving time calculated at a different time by the moving speed calculating means.

12. A stride measuring apparatus comprising:

a belt having a running surface for a subject to run or walk, the belt being driven in a predetermined direction;

a plurality of signal wave emitting means placed at positions along an edge part of the running surface and at predetermined intervals and each configured to emit a signal wave in a direction intersecting with the predetermined direction and at a predetermined height above the running surface;

a plurality of signal wave detecting means placed at positions along an edge part of the running surface and each configured to receive a signal wave emitted by a corresponding signal wave emitting means, to output a first signal when a foot of the subject passes across the signal wave, and to output a second signal when no foot of the subject passes across the signal wave;

line detecting means for detecting a line that fits a variable set containing variables with parameters of an output time of the first signal or the second signal outputted from the signal wave detecting means, and the position of the signal wave detecting means, the variable set being obtained with movement of a foot of the subject in the predetermined direction; and

stride calculating means for calculating a stride, based on a distance between intersecting points of a line passing an arbitrary time, with two lines detected in succession by the line detecting means.

13. The stride measuring apparatus according to claim 12, wherein the running surface of the belt is driven in the predetermined direction from one end to another end,

the stride measuring apparatus further comprising landing time detecting means for detecting a variable whose error relative to the line detected with use of the variable set is within a predetermined value, said variable containing as a parameter a position closest to said one end, out of the variables in the variable set, for detecting a variable containing as parameters an output time later than an output time included in the detected variable, and a position on the one end side with respect to the position included in the detected variable, and for detecting the output time included in the detected variable, as a landing time.

14. The stride measuring apparatus according to claim 13, further comprising moving speed detecting means for calculating a foot speed, based on a calculation of a quotient between a stride time and the stride, where the stride time is a duration between two landing times detected in succession by the landing time detecting means.

15. The stride measuring apparatus according to claim 12, further comprising:

second signal wave emitting means placed at a position along an edge part of the running surface and configured to emit a second signal wave in a direction intersecting with the predetermined direction;

second signal wave detecting means for receiving a reflected wave of the second signal wave; and

left/right determining means for determining whether the stride calculated by the stride calculating means is a stride of the left foot or a stride of the right foot of the subject, based on a period of time between an emission time and a reception time of the second signal wave.