JP2008173365A - Gait analysis system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gait analysis system for measuring movement of a walker's feet three-dimensionally without imposing loads on the walker thereby measuring and analyzing spatial movements of a swinging leg. <P>SOLUTION: The gait analysis system includes: a walking sensor which is fitted to the walker's foot part, detects at least either a prescribed time acceleration or an angular-velocity with a timer activated by a measurement start command, and radio outputs detection data; radio communication device for communicating with the walking sensor to collect the detection data and notifying the walking sensor about the measurement start command; and a gait analyzing device for transferring the measurement start command to the radio communication device and calculating two-dimensional or three-dimensional position information and state information of the foot part during an optional period on the basis of the detection data acquired via the radio communication device. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gait analysis system capable of obtaining a quantitative measure of rehabilitation, work efficiency improvement, and ability improvement by measuring and analyzing a pedestrian's walking state and making individual walking patterns identifiable. It is.

  Patent Document 1 discloses a technical disclosure regarding walking analysis for calculating walking data from a measurement result of a foot pressure distribution obtained using a pressure sensor. FIG. 11 is an overview of the gait analyzer described in Patent Document 1.

  A feature of the present invention is that a person walks on the pressure sensor unit 101 installed in a band shape on the floor, the measurement results of the foot pressure distribution are analyzed by the analyzers 102 to 105, and a parameter reflecting the good way of walking is output. In the configuration.

Japanese Patent Laid-Open No. 11-113884

The conventional walking analysis method has the following problems.
(1) In the invention described in Patent Document 1, a pressure sensor for measuring a foot pressure distribution is laid on the floor or the ground, a pedestrian walks on the floor, and performs a gait analysis from the foot pressure distribution during walking. . In this case, the pressure sensor must be installed in a place where the user walks in advance, resulting in restrictions on the installation location. In addition, depending on the walking distance, a plurality of pressure sensors must be prepared.

(2) Further, since walking on the pressure sensor, a sense and consciousness different from the daily walking of the patient may occur, and the walking result may differ.

(3) Since the walking result is also limited to the footprint, the spatial movement of the free leg cannot be measured and analyzed. Also, the time relationship between the left and right walking data is acquired, and it is not possible to accurately detect both foot support and step time which are important in walking analysis.

  The present invention has been made to solve the above-described problems, and measures the pedestrian's foot movement in a three-dimensional manner without giving a load to the pedestrian, thereby measuring the spatial movement of the free leg. It aims to realize a gait analysis system that can be analyzed.

In order to achieve such a subject, the present invention has the following configuration.
(1) A walking sensor that is attached to a pedestrian's foot and detects at least one of acceleration or angular velocity for a predetermined time by a timer that is activated by a measurement start command, and wirelessly outputs detection data;
A wireless communication device that communicates with the walking sensor and collects the detection data, and notifies the walking sensor of the measurement start command;
A walk for passing the measurement start command to the wireless communication device and calculating two-dimensional or three-dimensional position information and state information of the foot at an arbitrary time based on the detection data acquired via the wireless communication device. An analysis device;
A gait analysis system comprising:

(2) The walk analysis system according to (1), wherein the timers included in the plurality of walk sensors are started in synchronization with a measurement start command notified from the wireless communication device.

(3) The stop state of the foot is determined by satisfying at least one of a condition that the detected value of the angular velocity is not more than a certain threshold value or the detected value of the acceleration is not more than a certain threshold value. The walking analysis system according to (1) or (2).

(4) The walking sensor includes at least one of an acceleration sensor in the X, Y, and Z directions and an angular velocity sensor in the X, Y, and Z directions, according to any one of (1) to (3). Gait analysis system.

(5) The walking analysis system according to any one of (1) to (4), wherein the walking sensor is mounted in the vicinity of a toe portion of the footwear of the pedestrian.

(6) The walking analysis system according to any one of (1) to (4), wherein the walking sensor is mounted in the vicinity of a heel portion of the footwear of the pedestrian.

(7) The pedometer analysis system according to any one of (1) to (6), wherein the wireless communication device is a wireless access point formed on a network.

(8) The walking analysis system according to (7), wherein the walking analysis device acquires the detection data from the wireless access point via a network.

(9) The walking analysis device calculates a relative movement distance by a predetermined walking analysis algorithm for processing the detection data, and based on the relative movement distance, a walking position, a walking time, a stride, a walking speed, a walking rate, and a stance. The gait analysis system according to any one of (1) to (8), wherein state information of at least one of rate and swing rate data is calculated.

(10) The gait analysis device calculates two-dimensional or three-dimensional angles, velocities, and moving distances by integrating at least one of angular velocity and acceleration for each step. (1) to (9) The gait analysis system according to any one of the above.

According to the present invention, the following effects can be expected.
Since walking data can be easily acquired, it can be easily used in rehabilitation and other hospital treatment settings.

Since the walking sensor can be attached to the shoe, the pedestrian only needs to wear the shoe. For this reason, without being conscious of measurement, it is possible to walk freely with the same feeling as normal walking, and the burden on the subject is extremely small.

(3) Since the walking sensor can be mounted in a very small size, there are few restrictions on the measurement location. In addition, it can be used in a rehabilitation training room where many people are present.

(4) Since the walking data can be stored in the walking analysis device, it is possible to easily grasp the change of the walking state by comparing the past and current state of the pedestrian, and quantify the degree of rehabilitation recovery. Can be grasped.

(5) A 3-axis acceleration sensor built in the walking sensor means and a 3-axis angular velocity (gyro) sensor can calculate the movement of the foot in the three-dimensional space by computing the output of the walking pattern. Differences can be analyzed from the top, bottom, left and right.

(6) The time relationship between the left and right walking data can be acquired, and both foot support and step time important in walking analysis can be accurately detected.

(7) Especially in application to rehabilitation, it is possible to analyze the difference in the way of walking depending on the contents of the obstacle, and to analyze the movement of the unlanded foot (free leg), which is impossible with the footprint analysis using the pressure sensitive mat. .

(8) Since the number of sensors that can transmit and receive data to and from the wireless access point is not limited to one, simultaneous analysis can be performed even when a plurality of people are walking.

  The present invention will be described in detail below with reference to the drawings. FIG. 1 is a functional block diagram showing an embodiment of a gait analysis system to which the present invention is applied. The walking analysis system of this embodiment includes a walking sensor 1, a wireless access point 2, a network 3, and a walking analysis device 4.

  The walking sensor 1 is attached to one foot or both feet of the pedestrian M directly or on footwear (toe or heel), and includes an acceleration sensor 11, an angular velocity sensor 12, a timer 13, and a wireless interface 14, and is one of the wireless communication devices. Wireless communication is performed with the wireless access point 2 in the form.

  The wireless access point 2 includes a wireless interface 21 that communicates with the walking sensor 1 and a network interface 22 that connects to the network 3, and passes walking data collected from the walking sensor 1 to the walking analysis device 4 via the network 3.

  The gait analysis device 4 includes a gait data measurement unit 41, a gait data analysis unit 42, a timer control unit 43, and a network interface 44, stores gait data passed from the wireless access point 2, and uses a gait analysis algorithm to move relative distances. Is calculated.

  Furthermore, the gait analysis device 4 executes various analyzes by the gait analysis application based on the relative movement distance. The analysis target items are a walking position, a walking time, a stride, a walking speed, a walking rate, a stance rate, a free leg rate, and the like.

  FIG. 2 is a functional block diagram illustrating a configuration example of the walking sensor 1. Three acceleration sensors 11 that detect acceleration in the X, Y, and Z axis directions, three angular velocity sensors 12 that detect angular velocities in the X, Y, and Z axis directions, and A / A D converter 15 is provided.

  The output of the A / D converter 15 is passed to the CPU 16 to execute a predetermined calculation process. The CPU 16 has a memory resource 17 such as a ROM or a RAM, and can temporarily store detected data. The walking sensor 1 includes a power supply unit 19 including a rechargeable battery and a charging circuit.

  When the CPU 16 acquires a measurement start command from the wireless access point 2 via the wireless interface 14, the timer 13 is activated and collection of detection data is started. The detection data for a predetermined period is temporarily stored in the memory resource 17 with a time-series sequence number for timer activation.

  The data temporarily stored in the memory resource is transmitted from the wireless antenna 18 to the wireless access point 2 through the wireless interface 14 with a sequence number assigned to each appropriate amount of data. The wireless access point 2 transfers this data to the walking analysis device 4 via the network 3.

  These elements constituting the gait sensor 1 can be mounted as a very small chip, and the pedestrian is not aware of measurement when worn directly or on footwear on one or both feet of the pedestrian. Since it is possible to walk freely with the same feeling as normal walking, the burden on the subject can be extremely reduced.

  FIG. 3 is a sequence diagram for explaining timer activation of a plurality of walking sensors based on a measurement start command from the walking analysis device 4. A measurement start command from the walking analysis device 4 is passed to the wireless access point 2 via the network. The wireless access point 2 notifies the plurality of walking sensors 1A, 1B, 1C,.

  The timers included in the walking sensors 1A, 1B, 1C,... Are started in synchronization with acquisition of a measurement start command from the wireless access point 2, and measurement (collection of detection data) is started. Detection data for a predetermined period is temporarily stored in a memory resource with a time-series sequence number for timer activation.

  Data temporarily stored in the memory resource is transmitted to the wireless access point 2 with a sequence number assigned for each appropriate amount of data. The wireless access point 2 collects detection data from the plurality of walking sensors 1A, 1B, 1C,... And transfers them to the walking analysis device 4.

  FIG. 4 is a functional block diagram illustrating a configuration example of the walking analysis apparatus. Data from the wireless access point 2 is passed to the CPU 45 via the network interface 44. The walking data collection means 411 of the walking data measuring unit 41 acquires walking data from the CPU 45, sorts the data in order of sequence numbers, and stores them in the measurement data file 412 for a predetermined period. The stored measurement data is acceleration and angular velocity data.

  The CPU 45 reads the stored data from the measurement data file 412 and passes it to the walking data analysis unit 42 to execute various analysis processes. The analysis result is output to the display device 5 and the printing device 6. Further, the CPU 45 communicates with the timer control unit 43 and passes a measurement start command to the wireless access point 2 via the network interface 44 and the network 3 at a predetermined cycle.

  The analysis result of the gait data analysis unit 42 can be distributed directly or via a network to an external device or organization, a doctor instructing rehabilitation, a physical therapist, or even a pedestrian.

  FIG. 5 is a functional block diagram illustrating a configuration example of the walking data analysis unit 42. The gait analysis unit 421 extracts the measurement data stored from the measurement data file 412, passes it to the gait analysis algorithm 421 </ b> A, executes various analyzes, and outputs the analysis results to the gait analysis application 422.

  The analysis result by the walking analysis application 422 is three-dimensional position information of the pedestrian's feet and walking state information such as walking time, speed, stance, and free leg data.

  The gait analysis algorithm 421A calculates the velocity by integrating the acceleration data stored in the measurement data file 412 once. This integration calculation is executed for each of the X, Y, and Z components.

  The calculated speed is integrated once more to become distance data. The angular velocity is similarly integrated and the angle is calculated. In this way, since three-axis data of X, Y, and Z is calculated, it is possible to obtain three-dimensional position information.

  At the same time, the walking analysis algorithm 421A calculates a break between steps in order to calculate walking state information. The step delimiter is determined by calculating a period during which the vehicle is supposed to be stopped from the acceleration and angular velocity data as a stop period, and dividing the period from the active period into the stop period.

  The detection of the foot stop state is determined by satisfying at least one of the following conditions: an angular velocity detection value equal to or less than a certain threshold value or an acceleration detection value equal to or less than a threshold value.

  The gait analysis algorithm 421A calculates state information related to walking, such as standing time (time when the foot is in contact with the ground) and free leg time (time when the foot is away from the ground), based on the break of the step.

  At least one of an angular velocity integration error and an acceleration integration error can be used as a means for correcting the distance error for each step. The calculated distance data is converted into coordinate data together with the angle data.

  The walking analysis application 422 that acquires the walking data of the position information and the state information from the walking analysis unit 421 can display the walking data on the display device 5 connected to the walking analysis device 4, and the user can easily walk. Can grasp.

  Further, since past data is stored as a file, the walking state from the past to the present can be referred to, and a change in the walking state can be displayed by a trend graph or the like. If necessary, output to the printing device 6 is also possible.

  FIG. 6 is a flowchart showing a signal processing procedure of the gait analysis algorithm. In step S1, the data based on the individual difference between the acceleration and angular velocity sensors is corrected, and in step S2, the stop of the step is detected. Specifically, a walking stop section is calculated from acceleration and angular velocity data.

  In step S3, the angular velocity data is integrated to calculate the angle. In step S4, the X, Y, and Z axes of acceleration and angular velocity are converted from local coordinates (coordinates on the sensor) to world coordinates (user space).

  In step S5, the acceleration data is integrated to calculate the speed. In step S6, position coordinates are calculated. Specifically, the distance is calculated by speed × sampling time, and the relative movement distance (position) is calculated by adding to the previous value.

  FIG. 7 is a flowchart showing a data processing procedure of the gait analysis application 422. In step S1, three-dimensional position information, step stop position information, and speed information are acquired as output data of the walking analysis algorithm 421A.

  In step S2, the output data acquired in step S1 is calculated, and walking state information such as walking time, walking speed, walking rate, stride, standing leg, and swing leg time is calculated.

  Next, with reference to FIG. 8 and FIG. 9, the effect in the case where the present invention is applied to walking rehabilitation will be described. FIG. 8 is a table showing the walking speed (meter / sec) and walking rate (number of steps / sec) of healthy persons of each age for both men and women.

  As shown in the table, the walking speed and walking rate differ depending on the age of each gender. When a person with a walking disability walks, the walking speed is slow and the walking rate is lower than the above standard. However, as it recovers by rehabilitation, it approaches the walking of the healthy person shown above.

  Therefore, by displaying the data for each gait measurement in the trend graph, it is possible to visually determine the degree of recovery of pedestrians and the progress of rehabilitation. Become.

  FIG. 9 is an image illustration explaining the stance phase of the left and right legs, the free leg phase, and the both-leg support phase, which are analysis items for rehabilitation. When walking, each leg has a “free leg phase” and a “standing phase”.

  “Free leg phase” means that the bottom of the leg is not in contact with the ground during walking, and is indicated by a frame with a horizontal line in the figure. “Standing phase” means that the bottom of the leg is in contact with the ground, and is indicated by a frame drawn by a vertical line in the figure.

“Both feet support” refers to the portion where the stance phases of each leg overlap, and in the figure, it can be seen that the portion where the vertical frame overlaps is the “both feet support” state. It is said that there is a relationship of the following formula in walking of a normal healthy person.
Standing leg: Swing leg phase: Supporting both legs = 6: 4: 2 (1)

  FIG. 10 is a trend graph in which the stance period (A), the swing leg period (B), and the both leg support period (C) of the left and right leg walking analysis items are arranged in time series. With the trend graph display, it can be visually determined that as the rehabilitation progresses, these displays approach the relationship of equation (1).

  The present invention can use walking data in real time after walking measurement is completed by using a walking sensor having a wireless communication function incorporating a triaxial acceleration sensor and a triaxial angular velocity sensor.

  Since the measured walking data and analysis data can be used in real time, the pedestrian can view the trend graph immediately after rehabilitation. Being able to immediately know the degree of recovery after rehabilitation helps encourage rehabilitation.

  In addition, by performing gait measurement before rehabilitation, a physical therapist or doctor can use it as data for selecting an optimal rehabilitation program for the pedestrian on that day.

Hereinafter, other embodiments of the present invention will be described.
(1) Since the gait analysis device 4 accumulates the gait data in a file and can calculate in real time and display the current gait trajectory on the screen, it can also grasp the movement of the patient in the hospital in real time. It becomes possible.

(2) Instead of the wireless access point 2 for collecting data from the walking sensor 1, a portable terminal equipped with a wireless communication function and a data storage function, which is worn by an assistant who guides rehabilitation, can be used.

(3) The walking data collected by the portable terminal for a predetermined period is transferred to the walking analysis device 4 by USB cable means, wireless LAN, or the like. Alternatively, the data storage unit of the portable terminal can be detachable storage means (portable HDD, USB clip memory, etc.), and this can be removed and directly connected to the gait analyzer 4 to pass the stored data.

(4) The walking sensor 1 has an arithmetic processing function by the CPU 15 and executes primary processing such as filter processing of measured values in the walking sensor 1, thereby wireless communication data to a wireless access point or a portable terminal. The communication speed can be improved by reducing the amount.

It is a functional block diagram which shows the basic composition of the gait analysis system to which this invention is applied. It is a functional block diagram which shows the structural example of a walking sensor. It is a sequence diagram explaining timer activation of a plurality of walk sensors based on a measurement start command. It is a functional block diagram which shows the structural example of a walk analysis apparatus. It is a functional block diagram which shows the structural example of a walk data analysis part. It is a flowchart which shows the signal processing procedure of a walk analysis algorithm. It is a flowchart figure which shows the data processing procedure of a walk analysis application. It is the table | surface which showed the value of the walking speed and walking rate of the healthy person of each age of man and woman. It is an image figure explaining the stance phase of a right-and-left leg, a free leg phase, and both feet support phase. It is a trend graph that arranges the stance phase of the left and right legs, the swing leg phase, and the support phase of both feet in chronological order. It is a general-view figure of the walk analysis device indicated in patent documents 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Walk sensor 11 Acceleration sensor 12 Angular velocity sensor 13 Timer 14 Wireless interface 2 Wireless access point 21 Wireless interface 22 Network interface 3 Network 4 Walk analysis apparatus 41 Walk data measurement part 42 Walk data analysis part 43 Timer control part 44 Network interface

Claims (10)

A walking sensor that is mounted on a pedestrian's foot and detects at least one of acceleration or angular velocity for a predetermined time by a timer that is activated by a measurement start command, and wirelessly outputs detection data;
A wireless communication device that communicates with the walking sensor and collects the detection data, and notifies the walking sensor of the measurement start command;
A walk for passing the measurement start command to the wireless communication device and calculating two-dimensional or three-dimensional position information and state information of the foot at an arbitrary time based on the detection data acquired via the wireless communication device. An analysis device;
A gait analysis system comprising:   The gait analysis system according to claim 1, wherein the timers included in the plurality of gait sensors are activated in synchronization with a measurement start command notified from the wireless communication device.   The detection of the foot stop state is performed by satisfying at least one of a condition that the detected value of the angular velocity is not more than a certain threshold value or the detected value of the acceleration is not more than a certain threshold value. The gait analysis system according to 1 or 2.   The gait analysis system according to any one of claims 1 to 3, wherein the gait sensor includes at least one of an acceleration sensor in the X, Y, and Z directions and an angular velocity sensor in the X, Y, and Z directions.   The gait analysis system according to any one of claims 1 to 4, wherein the gait sensor is mounted in the vicinity of a toe portion of the footwear of the pedestrian.   The gait analysis system according to any one of claims 1 to 4, wherein the gait sensor is mounted in the vicinity of a heel part of footwear of the pedestrian.   The pedometer analysis system according to claim 1, wherein the wireless communication device is a wireless access point formed on a network.   The gait analysis system according to claim 7, wherein the gait analysis device acquires the detection data from the wireless access point via a network.   The walking analysis device calculates a relative movement distance by a predetermined walking analysis algorithm that processes the detection data, and based on the relative movement distance, a walking position, a walking time, a stride, a walking speed, a walking rate, a stance rate, The gait analysis system according to any one of claims 1 to 8, wherein at least any state information of the pedometer data is calculated.   10. The walk analysis device according to claim 1, wherein at least one of angular velocity and acceleration for each step is integrated to calculate a two-dimensional or three-dimensional angle, velocity, and moving distance. Gait analysis system.

Images