JP2009050533A - Self-walking supporting apparatus, and program being used for it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a self-walking supporting apparatus which can more quickly correspond to a disturbance, and to provide a program which is used for the apparatus. <P>SOLUTION: This self-walking supporting apparatus includes a sensor section, a disturbance responding section, and an electric stimulation section. In this case, the sensor section is arranged on the leg section of a walk supporting subject. The disturbance responding section identifies a disturbance conforming to the output from the sensor section and prepares and outputs a stimulation signal for coping with the disturbance. The electric stimulation section can apply an electric stimulation to the leg section of the walk supporting subject conforming to the stimulation signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an independent walking support device and a program used therefor.

  Elderly people and those with reduced gait function, including those with hemiplegia, are unable to cope with disturbances based on obstacles, rough terrain, etc. due to weak sensation related to walking and impaired neuromuscular skeletal function. The fall caused by these disturbances during walking is a major risk factor. Therefore, self-supporting walking support that can cope with these disturbances is a very important matter for persons with reduced walking function.

  Conventionally, a plurality of measurements such as electromyogram measurement and indirect angle measurement have been proposed for measuring disturbances that occur during walking. However, all of the above not only have a problem in measurement accuracy, but also have a problem in the time until it is determined that it is a disturbance. That is, in order to judge that it is a disturbance and to respond quickly to the disturbance and recover the posture collapsed by the disturbance of the person with reduced walking function, there are still problems to be solved.

  In view of the above, an object of the present invention is to solve the above-described problems and provide an independent walking support device that can respond more quickly to disturbances and a program used therefor.

  A self-supporting walking support device according to one means of the present invention is configured to identify a disturbance based on an output from a sensor unit and a sensor unit for placing on a leg of a walking support target person, and to provide a stimulation signal for dealing with the disturbance. A disturbance identification unit to be created and output, and an electrical stimulation unit capable of applying electrical stimulation to the leg of the walking support target person based on the stimulation signal.

  In addition, the independent walking support program according to another aspect of the present invention includes a data acquisition unit that acquires data from an acceleration sensor in a time series in a computer, and a feature extraction that extracts a feature amount based on the time series data. And a determination unit for identifying whether or not the disturbance is based on the feature amount, and a stimulus generation unit that generates a stimulus signal when the determination unit determines that the disturbance is present.

  As described above, according to the present invention, it is possible to provide an independent walking support apparatus that can quickly cope with disturbance and a program used therefor.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating an outline of an independent walking support device according to the present embodiment. As shown in FIG. 1, an independent walking support device 1 according to this embodiment includes a sensor unit 2 and a disturbance response unit 3 that receives an output of a signal from the sensor unit 2 and identifies a disturbance and creates a stimulus signal. And an electrical stimulation unit 4 that applies electrical stimulation based on a signal from the disturbance response unit 3.

  The sensor unit 2 according to the present embodiment is attached to the foot of an independent walking support target person, preferably in the vicinity of the ankle, and preferably includes at least one of a plurality of acceleration sensors and angular velocity sensors. It is an aspect. In addition, the plurality of acceleration sensors here uses the walking direction (traveling direction) of the person with reduced walking function as the X-axis, the axis parallel to the walking surface (ground) and perpendicular to the X-axis as the Y-axis, and the walking surface. When the axis perpendicular to the X axis is the Z axis, it is preferably arranged so that the acceleration on each of the X axis, the Y axis, and the Z axis can be measured. The sensor is preferably arranged so as to be able to measure angular velocities that rotate about these X, Y, and Z axes. FIG. 2 shows a schematic diagram regarding the arrangement of the acceleration sensor and the angular velocity sensor according to the present embodiment. The configurations of the acceleration sensor and the angular velocity sensor are not particularly limited, and a commercially available well-known one can be adopted. From the viewpoint of realizing the above functions, the accelerometer measurement range +5 g, the angular velocity meter measurement range Those of about ± 200 degrees / s are preferred.

  FIG. 3 is a functional block diagram of the disturbance response unit 3 according to the present embodiment. The disturbance response unit 3 according to the present embodiment outputs a disturbance identification unit 31 that identifies a disturbance and the electrical stimulation unit 4 so that the disturbance identification unit 31 can cope with the disturbance when the disturbance identification unit 31 identifies the disturbance. And a stimulus creating unit 32 that creates a signal (stimulus signal). In this embodiment, since the signal output from the sensor unit 2 is generally analog data, an analog / digital converter (hereinafter, referred to as “analog / digital converter”) that converts the analog data into digital data before the disturbance response unit 3. It is preferable to have “AD converter”.

  The disturbance identification unit 31 is a unit that identifies whether or not a disturbance has occurred. As shown in FIG. 3, the disturbance identification unit 31 includes a data acquisition unit 311 that acquires data output from each of a plurality of acceleration sensors or angular velocity sensors in time series, and each time acquired by the data acquisition unit 311. It comprises at least a feature extraction unit 312 that extracts feature amounts from serial data and a determination unit 313 that identifies whether or not there is a disturbance based on the feature extraction amounts.

  The data acquisition unit 311 according to the present embodiment acquires changes over time in acceleration or angular velocity as data. FIG. 4 is a diagram showing acceleration in the X-axis direction attached to the collar as an example, in which the horizontal axis represents time and the vertical axis represents a voltage value corresponding to the acceleration. Also, in the example in this figure, a large change in acceleration, which can be attributed to the ground contact, can be seen.

  The feature extraction unit 312 according to the present embodiment extracts feature amounts based on the time series data acquired by the data acquisition unit 311. Although it is not necessarily limited as the feature amount, among the time-series data acquired by the data acquisition unit 311, the acceleration after a certain period of time has elapsed from the change in acceleration or angular velocity that is considered to be caused by the ground contact of the heel during walking. It is preferable to adopt the value of or the angular velocity. In the present embodiment, the period is preferably within a range of 100 ms or less from the time considered to be caused by ground contact of the bag. By setting it within this range, it is considered that appropriate support can be provided to persons with reduced walking function within a range of 200 ms or less after the occurrence of a disturbance, and recovery to an appropriate posture can be performed.

  In the present embodiment, the feature quantity to be extracted is particularly preferably an angular velocity with respect to the Y axis. The inventors of the present invention have studied in detail about various methods for more efficiently determining whether or not a disturbance is present, including the acceleration and angular velocity of the head, hips, and legs during walking. In the case of using the above cluster classification method, it has been found that it is easy to identify whether or not the sensor at the moment when the Davis value is low is a disturbance, and in particular, it has been found that the angular velocity with respect to the Y axis can be classified more efficiently.

  The determination unit 313 according to the present embodiment determines whether or not the disturbance is based on the extracted feature amount. This discriminating method is not limited, but so-called discriminant analysis is suitable, for example. Here, the discriminant analysis is not limited, but, for example, as shown in the conceptual diagram of FIG. 5, on one side of the region divided by this straight line with respect to the distribution of the feature amount with reference to a single straight line. An analysis that determines whether each feature is a disturbance or not.

  The stimulus creating unit 32 is a unit that creates a stimulus signal for the electrical stimulating unit 4 when the determining unit 313 identifies a disturbance. The stimulation signal is not limited, but is preferably an electrical signal for stimulating the main muscle groups of the lower limbs. For example, in the case of a symptomatic patient having paralysis symptoms in the muscle groups, the Achilles tendon and the back of the knee It is preferable that the signal is a stimulation signal for stimulating the total rib embryonic nerve (this makes it easier to raise the thigh and makes it easier to respond to disturbance).

  The electrical stimulation unit 4 according to the present embodiment is for receiving signals from the disturbance response unit 3 and stimulating the lower limb major muscle groups. As this configuration, the number and position need to be appropriately adjusted depending on the state of the support target person, etc., but it is preferably arranged on the leg of a person with reduced walking function, for example, in the lower limb major muscle group. As an example in the case of a symptomatic patient having a paralytic symptom, an example in which the patient is placed near the knee sole and the Achilles tendon can be given. In addition, as a structure of the electric stimulation part 4, a well-known structure can be employ | adopted without being limited, For example, it is a preferable aspect that it is what is called an electric pad.

  Here, the usage pattern of the independent walking support device according to the present embodiment will be described. First, the independent walking support target wears a sensor unit and an electrical stimulation unit on his / her foot and connects them to a disturbance response unit. The independent walking support target starts walking, and the disturbance response unit acquires time-series data of acceleration and angular velocity generated by walking. And a disturbance response part acquires the value of the acceleration or angular velocity after progress for a fixed period (for example, 100 ms) from the time of heel contact among the time series data acquired as a feature amount. Then, the disturbance response unit performs discriminant analysis on the feature amount, recognizes whether or not it is a disturbance, and if it is determined as a disturbance, creates a stimulation signal and outputs the stimulation signal to the electrical stimulation unit. If it is determined that there is no disturbance, the process proceeds to the time-series data acquisition process without creating a stimulus signal.

  By the above operation, it is possible to provide an independent walking support device that can quickly respond to disturbances and a program used therefor. In particular, the self-sustained walking support device according to the present embodiment can be realized with the minimum necessary configuration such as a sensor unit, a disturbance response unit, and an electrical stimulation unit, and can ensure the convenience of daily life and the high speed of calculation.

(Embodiment 2)
The independent walking support device according to the present embodiment is substantially the same as that of the first embodiment except that the determination method of the determination unit 313 in the disturbance response unit 3 is different. Hereinafter, different parts will be mainly described. The description of other parts is omitted.

  The discrimination unit 313 according to the present embodiment is different from the first embodiment in that a neural network (NN) is used for discrimination processing. The neural network used in the present embodiment is not limited, but a back propagation method is a preferred aspect. An outline of the neural network is shown in FIG.

  As described above, according to the present embodiment, it is possible to provide an independent walking support apparatus that can respond more quickly to disturbances and a program used therefor, and the use of the neural network according to the present embodiment increases the robustness with respect to speed. In addition, there is an advantage that individual differences can be absorbed.

  In addition, the determination method according to the present embodiment and the determination method according to the first embodiment can be used at the same time, or only one of them can be adopted, and there is no particular limitation.

(Example 1)
About the self-supporting walking assistance apparatus which concerns on above-described embodiment, it created actually and confirmed about the operation | movement. This will be described below.

  First, for 9 healthy persons (22 to 37 years old, all male) who agreed to participate in the experiment, acceleration sensors and angular velocity sensors were attached to the head, waist, and feet, respectively, and the X, Y, and Z axes were attached. In either case, measurement is possible, each sensor is connected to an information processing apparatus, and outputs from these sensors can be captured via an AD converter. Further, the discriminating unit of this embodiment performed both discriminant analysis and analysis by a neural network.

Next, for each healthy person, walk on the separate treadmill on both sides at 3 km / h. When the walking is stable, look at the timing when the heel touches down, and the left side speed is 0.5 km / h for 1 second. We observed changes in walking. This operation was performed 15 times for each healthy person. Of these results, the feature quantities extracted from each of the feet, hips, and head, and the number of successful judgments as to whether the extracted feature quantities have changed due to disturbance or normal walking are shown in Table 1 below. In addition, only the angular velocity based on the Y axis of the foot is extracted as a feature amount, and the number of successful discrimination results as a result of using the neutral network is shown in Table 2. FIG. 7 shows the change in angular velocity with respect to the Y axis of the foot over time.

  As a result, it was confirmed that all of them had a very high judgment rate. In particular, in the case of the foot angular velocity, it was confirmed that if a plurality of feature amounts were extracted from the time of heel contact, disturbance could be determined at almost 100%.

  Further examination based on the present example confirmed that even when the walking speed was changed during normal walking and the speed of the disturbance applied was changed, a very high discrimination result was shown. did it.

(Example 2)
In this example, for a female paralyzed patient who has consented to participate in the experiment, an angular velocity sensor is attached to the foot so that measurement on the Y axis is possible, this sensor is connected to an information processing device, and an AD converter is used. The output from these sensors can be captured. In this embodiment, an electrical stimulation device (NIHON MEDIA) and an electrical pad (Technogel, SR-5050, Sekisui) connected to the information processing device are attached to the Achilles tendon and the back of the knee, and the timing of raising the left leg is measured. Experiments were performed for both cases where the two locations were electrically stimulated (FES support) and not at this timing.

In this example, the subject is walked on a treadmill on both sides separated at 0.4 km / h, and when walking is stabilized, the timing at which the heel touches the ground is set, the speed on the left side is set to 0.1 km / h, Changes were observed. This operation was performed 5 times. Among these results, Table 4 shows the feature quantity of angular velocity based on the Y axis of the foot and the number of successful discriminations. In this example, the determination was performed by combining a plurality of results obtained by changing the time elapsed from the saddle contact time.

  As a result, it was confirmed that all of them had a very high judgment rate. In particular, in this example, since the judgment by the neural network is used, it was confirmed that individual differences can be dealt with. Furthermore, even when FES support was performed, it was possible to reliably detect disturbances and to confirm that the device was a highly accurate independent walking support device.

  INDUSTRIAL APPLICABILITY The present invention has industrial applicability as a self-supporting walking support device, and the program used there naturally has industrial applicability.

It is a figure which shows the outline of the self-supporting walking assistance apparatus which concerns on Embodiment 1. FIG. FIG. 4 is a diagram illustrating an outline regarding the arrangement of sensor units according to the first embodiment. 3 is a functional block diagram of a disturbance response unit according to Embodiment 1. FIG. 6 is a diagram illustrating an example of time-series data according to the first embodiment. FIG. It is a figure which shows the outline of discriminant analysis of the discrimination | determination part concerning Embodiment 1. FIG. It is a figure which shows the outline of the neural network of the discrimination | determination part concerning Embodiment 2. FIG. It is a figure which shows the example of the time series data of the angular velocity with respect to the Y-axis which concerns on Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Independent walking assistance apparatus, 2 ... Sensor part, 3 ... Disturbance discrimination part, 4 ... Electrical stimulation part

Claims (9)

A sensor unit for placement on the legs of the walking support target person;
A disturbance response unit that identifies a disturbance based on an output from the sensor unit, creates and outputs a stimulus signal for responding to the disturbance, and
An independent walking support device comprising: an electrical stimulation unit capable of applying electrical stimulation to a leg of a walking support target person based on the stimulation signal.   The independent walking support device according to claim 1, wherein the sensor unit includes an acceleration sensor or an angular velocity sensor.   The acceleration sensor is arranged to detect accelerations on the respective axes when the walking direction of the walking support target is the X axis and the two axes perpendicular to the X axis are the Y axis and the Z axis. The self-supporting walking support device according to claim 2.   The angular velocity sensor is arranged to detect angular velocities with respect to the respective axes when the traveling direction of the walking support target is the X axis and the axes perpendicular to the X axis are the Y axis and the Z axis. Item 3. The self-supporting walking support device according to Item 2.   The disturbance response unit includes a data acquisition unit that acquires data output from the acceleration sensor in a time series, a feature extraction unit that extracts a feature amount in the time series data acquired by the data acquisition unit, and The independent walking support device according to claim 1, further comprising: a determination unit that identifies whether the disturbance is based on a feature amount; and a stimulus creation unit that creates a stimulus signal when the determination unit determines that the disturbance is a disturbance. .   The autonomous walking support device according to claim 5, wherein the feature amount is an angular velocity with respect to the Y axis.   The autonomous walking support device according to claim 4, wherein the feature amount is an angular velocity with respect to the Y axis within 100 ms from when the heel is touched. On the computer,
A data acquisition unit for acquiring data from the acceleration sensor in time series,
A feature extraction unit that extracts a feature amount based on the time-series data;
A discriminating unit for identifying whether the disturbance is based on the feature amount;
An independent walking support program for functioning as a stimulus creating unit that creates a stimulus signal when the discriminating unit judges that it is a disturbance. The self-supporting walking support program according to claim 7, wherein the feature amount is an angular velocity with respect to a Y-axis of an angular velocity sensor installed on a human foot.