JP6161001B2 - Measuring device, wearable motion assist device and wound risk evaluation method thereof - Google Patents

Description

  The present invention relates to a measuring device that is attached to a human body or a prosthetic limb and measures a slip amount, a sliding speed, a force, and a moment. The present invention also relates to a wearable movement assist device that wears the measuring device on a human body and assists the movement of the human body. In particular, the present invention relates to an apparatus capable of easily evaluating a wound risk by detecting a slip between a human body or a prosthetic limb and a contact portion. The present invention also relates to a wound risk evaluation method.

  A device that is attached to the human body and assists in actions when a person becomes unable to perform a desired action due to an accident, injury, failure, aging, etc., or when it is desired to reduce the load associated with the action, has attracted attention (for example, Patent Document 1). By assisting the operation with this wearable motion assisting device, it is intended to help rehabilitation and improve work efficiency.

  In such a wearable movement assist device, a contact portion such as a cuff and a human body are brought into contact with each other, and the operation is assisted by transmitting a force through the contact portion. Here, slipping occurs between the contact portion and the human body due to factors such as the movement of the joints of the human body and the difference in the rotation mechanism of the apparatus. Therefore, a burden is applied to the skin of the part which a contact part contacts, and a wound may be borne. Since the wearable motion assist device is used in direct contact with the human body, special consideration is necessary for safety, and it is necessary to sufficiently evaluate the wound risk.

  In order to evaluate the wound risk, it is conceivable to measure and evaluate slippage between the contact portion of the device and the human body (relative position and speed of the human body with respect to the contact portion; slip amount and slip speed). For example, in Non-Patent Document 1, a slip sensor having the following configuration is used as a manipulator. The slip sensor described in Non-Patent Document 1 includes a laser, a diffraction grating having a stripe pattern, a lens, and a phototransistor. The diffraction grating is disposed in the vicinity of the laser emission port. The laser beam that has passed through the diffraction grating is collected by a lens and then irradiated onto an object, and scattered light from the object (skin) is detected by a phototransistor. Then, the autocorrelation of the signal detected by the phototransistor is obtained, and Fourier transform is performed to obtain the peak frequency f of the power spectrum. The slip velocity v of the object can be calculated from the frequency f and the grating interval d of the diffraction grating by v = f · d.

JP 2013-173190 A

Toshiaki Kuroda, Hideo Kitagawa, Fumio Matsuda, Yoshiki Uchikawa, Shuzo Hattori, Development of lattice image projection type non-contact small slip sensor, Journal of the Robotics Society of Japan, Vol.9, No.4, pp.464-468, 1991

  In the slip sensor of Non-Patent Document 1, only a one-dimensional displacement can be measured in principle, and a multi-directional displacement cannot be measured. Therefore, in order to measure displacement in multiple directions, it is necessary to provide a plurality of slip sensors of Non-Patent Document 1.

  However, the slip sensor of Non-Patent Document 1 is relatively large, and if it is intended to provide a plurality of sensors, it is necessary to reduce the size of the device, and a large development cost is required. Further, the slip sensor of Non-Patent Document 1 has a problem that it is difficult to improve the measurement accuracy because the measurement accuracy is determined by the grating interval of the diffraction grating. For these reasons, the wearable movement assist device including the slip sensor of Non-Patent Document 1 has not been put into practical use.

  Therefore, an object of the present invention is to provide a wearable movement assist device capable of measuring a slip amount and evaluating a wound risk.

  The present invention relates to a contact device that is brought into contact with a human body or a prosthetic limb in contact with the human body or the prosthetic limb in a measuring device that measures the relative slip amount, the sliding speed of the human body or the prosthetic limb, and the force or moment from the human body or the prosthetic limb. Two slip sensors that measure the sliding amount and sliding speed of the human body and the prosthetic limb with respect to the contact portion at the contact portion and the contact portion, and the force and moment from the human body and the prosthetic limb at the contact portion are measured. A slip sensor, a light emitting device that emits light to the human body and the prosthetic limb, and a light that is reflected by the human body and the prosthetic limb to acquire an image, and the time change of the image An image sensor that calculates a slip amount and a slip speed from the slip amount and slip speed measured by the two slip sensors, and a slip amount and a slip around a rotation axis perpendicular to a plane formed by the two slip directions Speed Calculating a, that is the measurement apparatus according to claim.

  The two slip sensors may be provided to face each other across the action point of the force sensor, or may be provided to face in the longitudinal direction of the link.

  As the force sensor, a 3-axis force sensor, a 6-axis force sensor, or the like can be used. The force sensor is a sensor that detects at least three components of a force component in two orthogonal directions (x-axis and y-axis) in a contact plane and a moment component around an axis (z-axis) orthogonal to the two axes. That's fine. It is desirable to use a 6-axis force sensor to increase the accuracy of wound risk assessment. As the force sensor system, various conventionally known systems such as a system using a strain gauge, an optical system, and a system using a piezoelectric element can be used.

  Another aspect of the present invention is a wearable motion assisting device having a driving unit and the measuring device of the present invention connected to the driving unit via a link.

  The wearable movement assist device of the present invention may assist the operation at an arbitrary location. For example, it may be a foot, a waist, an arm, a shoulder, a finger, and the like, and may assist the movements of a plurality of places, or may assist the whole body.

  According to another aspect of the present invention, the wearable motion assisting device of the present invention is mounted on a human body to operate, and the human body with respect to the contact portion is in contact with the slip sensor and the force sensor of the wearable motion assisting device. Measure the amount of sliding, sliding speed, force, and moment, attach the measuring device of the present invention to the manipulator, attach the contact part of the measuring device to the prosthesis, and measure the amount of sliding, sliding speed, force, and moment measured By controlling the manipulator based on this, the contact part is moved to imitate the movement of the contact part during the movement of the human body, and the amount of sliding, the sliding speed, the force, and the moment during this imitation movement are measured and measured. A wound risk evaluation method for a wearable motion assist device, characterized in that a wound risk is evaluated from a value.

  According to the present invention, it is possible to easily measure the translational and rotational slippage and sliding speed between the wearing part and the human body and the prosthetic limb, as well as the force and moment from the skin against the wearing part, and the measured values thereof. Therefore, the wound risk can be easily evaluated.

The figure which showed the structure of the mounting | wearing type movement assistance apparatus of Example 1. FIG. The figure which showed the structure of the cuff. The figure which decomposed | disassembled and showed the structure of the connection part of the cuff 12 and the link 10. FIG. The figure which showed the structure of the slip sensor. The figure explaining the sliding speed of a rotation direction. The figure which showed the connection part of the cuff 12 and the link 10. FIG.

  Hereinafter, specific examples of the present invention will be described with reference to the drawings. However, the present invention is not limited to the examples.

[Configuration of wearable motion assist device]
FIG. 1 is a diagram illustrating a configuration of a wearable motion assisting apparatus 1 according to the first embodiment. As shown in FIG. 1, the wearing-type motion assisting device 1 according to the first embodiment is a device that is attached to a human foot 2, and includes two links 10 a and b and a drive unit 11 that connects the two links 10 a and b. And cuffs 12a and 12b (corresponding to contact portions of the present invention) connected to the links 10a and 10b, respectively. Hereinafter, each component of the wearable motion assist device 1 will be described in more detail.

  The drive part 11 is provided in the knee joint part as shown in FIG. One end of the links 10a and 10b is connected to the drive unit 11. The link 10a is provided along the lower knee portion of the foot 2, and the link 10b is provided along the upper knee portion. The drive unit 11 includes a motor that controls the force acting on the links 10a and 10b, an angle sensor that detects an angle formed by the links 10a and 10b, and a sensor that detects an output acting on the links 10a and 10b. (Neither shown). The drive unit 11 controls the motor based on the input from the user and the motion state of the user, thereby controlling the force acting on the links 10a and 10b. The movement state of the user is detected using, for example, a biosensor. When the angles of the links 10a and 10b reach desired positions, the links 10a and 10b can be stopped or the rotation directions of the links 10a and 10b can be reversed.

  A cuff 12a is connected to one end of the link 10a opposite to the side to which the drive unit 11 is connected. Similarly, a cuff 12b is connected to one end of the link 10b. The cuffs 12 a and b are in contact with the foot 2. Although not shown, a stretchable band is wound on the cuffs 12a, b, and the foot 2 and the cuffs 12a, b are in contact with each other.

  FIG. 2 is a diagram illustrating the configuration of the cuff 12a when viewed from the foot 2 side in the direction of the link 10a, and FIG. 6 is an enlarged view of a connection portion between the link 10a and the cuff 12a. FIG. 3 is an exploded view of the configuration of the connecting portion between the link 10a and the cuff 12a.

  The shape of the cuff 12 is a shape of a part of a cylinder along the shape of the lower knee portion of the foot 2 as shown in FIG. As shown in FIG. 3, the link 10 a and the cuff 12 a are connected via a force sensor 14. Further, as shown in FIG. 2, the cuff 12a is provided with a slip sensor package 15. The slip sensor package 15 has two slip sensors 15a and 15b. These cuffs 12a and 12b, force sensor 14 and slip sensor 15a and 15b correspond to the measuring device of the present invention. The two slip sensors 15a and 15b are provided apart from each other in the slip sensor package 15. Moreover, it is the position which opposes in a contact plane on both sides of the action point 16 of the force sensor 14, Comprising: It is provided facing the longitudinal direction of the link 10a. A hole 17 is provided in the cuff 12a, and one slip sensor package 15 is provided so as to be fitted into the hole.

  The shape of the cuff 12b is a shape of a part of a cylinder along the shape of the upper knee portion of the foot 2, and the other configuration is the same as that of the cuff 12a. The configuration of the connection portion between the link 10b and the cuff 12b is the same as the configuration of the connection portion between the link 10a and the cuff 12a.

[Operation of wearable motion assist device]
Next, operation | movement of the mounting | wearing type movement assistance apparatus 1 of Example 1 is demonstrated.

  When performing the operation of extending or bending the foot 2 with the mounting-type motion assisting device 1 according to the first embodiment mounted on the foot 2, an input from the user or an angle sensor of the driving unit 11 is provided. This is used to detect the movement state of the user.

  The drive unit 11 controls the motor based on the input from the user and the state of the user's movement and the values measured by the angle sensor and the output sensor of the drive unit 11, and outputs acting on the links 10a and 10b are output. Control to be a predetermined value.

  By controlling the links 10a and 10b by the drive unit 11, force is transmitted to the cuffs 12a and b connected to the links 10a and 10b, and further, the force is transmitted to the human body that the cuffs 12a and 12b contact. And the operation | movement which extends or bends the knee joint of the leg 2 is assisted by the force applied to the human body.

  For example, the following effects can be expected by using the wearable movement assist device 1 of the first embodiment. Wearable operation of the first embodiment for a person who has impaired motor function due to illness or injury, a person whose physical strength has decreased due to aging, or a person who performs a heavy load operation such as carrying heavy objects Operation can be facilitated by using the auxiliary device 1.

  Next, the configurations of the slip sensors 15a and 15b and the force sensor 14 of the cuffs 12a and b will be described in more detail.

[Configuration of slip sensor]
FIG. 4 is a diagram showing a configuration of the slip sensor 15a. The slip sensor 15b has the same configuration. As shown in FIG. 4, the slip sensor 15 a includes a substrate 150, a light emitting device 151 and an image sensor 153 that are disposed on the back surface of the substrate 150 (a surface opposite to the side on which the human body is irradiated with light), a substrate, 150 and a lens 152 disposed on the surface (surface on the side where light is irradiated on the human body). In addition, a light guide body 154 that penetrates from the back surface to the front surface of the substrate 150 and contacts the light emitting device 151 is provided.

  The light emitting device 151 is a semiconductor laser or a light emitting diode. As shown in FIG. 4, the light emitting device 151 is in contact with the light guide 154, and the light emitted from the light emitting device 151 is guided from the back surface side of the substrate 150 to the front surface side of the substrate 150 by the light guide body 154. It is irradiated to the human body side through. The light guide 154 is a translucent material, for example, the same material as the lens 152.

  The lens 152 is disposed so that light from the light emitting device 151 reflected by the human body is condensed on the image sensor 153 through the hole 154.

  The image sensor 153 receives the reflected light from the skin collected by the lens 151. The lens 152 is made of a translucent resin such as silicone resin, epoxy resin, or acrylic resin, and the hole 154 is filled with the same material as the lens 152. The image sensor 153 includes a light receiving element such as a CMOS and a calculation unit. The calculating means calculates a slip amount (relative position) of the lower knee portion of the foot 2 with respect to the slip sensor 15a in the contact portion of the cuff 12a from the time change of the image acquired by the light receiving element.

  The operation principle of the slip sensors 15a, 15b is summarized as follows. The light emitted from the light emitting device 151 is applied to the human body. Then, the light irregularly reflected by the human body is collected by the lens 152 and the collected light is received by the image sensor 153. As a result, the image sensor 153 acquires images of the human body surface near the slip sensors 15a and 15b at predetermined intervals. The image acquired last time is compared with the image acquired this time, and the same shape portion is detected. From the change in the same shape portion, the two-dimensional movement amount of the human body relative to the cuffs 12a, b, that is, the translation direction (two orthogonal axes (x-axis, x in the contact plane where the cuffs 12a, b and the human body contact). It is possible to calculate the slip amount (slip direction and distance) in the y-axis) direction, since the slip amount is repeatedly measured at a predetermined time interval Δt. In this way, the slip amount and the slip speed in the translation direction can be measured by the slip sensors 15a and 15b.

  Further, the translational slip amount and the slip speed measured by the two slip sensors 15a and 15b are transmitted to a calculation unit (not shown) in the slip sensor package 15. The calculation unit calculates the slip amount and slip speed in the rotational direction from the slip amount and slip speed in the translation direction. The rotation axis (z-axis) is perpendicular to the plane formed by the two slip directions measured by the slip sensors 15a and 15b, and passes through the slip sensor 15a in the xy plane forming a predetermined angle (for example, 90 °). It passes through the intersection of the straight line L1 and the straight line L2 in the xy plane passing through the slip sensor 15b and forming a predetermined angle (see FIG. 5). Further, the sliding speed in the rotation direction is ½ of the sum of the sliding speed v1 measured by the slip sensor 15a and the sliding speed v2 measured by the slip sensor 15b.

  Note that the calculation units for calculating the slip amount and the sliding speed in the rotation direction may be provided in the cuffs 12a and 12b, respectively, or in the drive unit 11.

[Configuration of force sensor]
Next, the configuration of the force sensor 14 will be described. The force sensor 14 is a three-axis or six-axis force sensor, and includes a three-dimensional (three-axis direction orthogonal to each other) force vector applied to the force sensor 14 from the skin in contact with the cuffs 12a and 12b, The moment around the axis can be measured.

  The force sensor 14 may employ various types of conventionally known methods other than those using a strain gauge. For example, a piezoelectric element or an optical element can be used.

  Further, a triaxial force sensor or the like can be used as the force sensor 14. In the first embodiment, two slip sensors 15 and one force sensor 14 are used. However, in order to improve measurement accuracy, three or more slip sensors 15 may be used. Two or more may be used.

[Arrangement of slip sensor and force sensor]
As shown in FIGS. 2 and 3, the two slip sensors 15 a and 15 b are spaced apart from each other in the longitudinal direction of the link 10 a in the contact plane (xy plane). Moreover, the force sensor 14 is arrange | positioned so that the action point of the force sensor 14 may come between two slip sensor 15a, b in a contact plane like FIG. By arranging the slip sensors 15a, 15b and the force sensor 14 in this way, measurement can be performed with high accuracy.

[Wound risk assessment method]
Next, a method for evaluating the skin wound risk in the cuff 12 will be described.

  First, the wearing-type motion assisting device 1 of the first embodiment is worn on the human foot 2 in the same manner as in FIG. The knee joint of the foot 2 is bent or extended in the worn state. At this time, the slip sensor 15a, b and the force sensor 14 of the wearable movement assist device 1 according to the first embodiment use the slip amount, the slip speed, the force, and the moment in the translational and rotational directions of the human body with respect to the cuff 12a, b. Measure. The measured value is recorded in a storage device such as a computer. In addition, the movement amount of the cuffs 12a and 12b viewed from the outside may be measured by motion capture.

  Next, the wearable motion assisting device 1 of the first embodiment is detached from the human body, and the same cuffs as the cuffs 12a and 12b of the wearable motion assisting device 1 of the first embodiment are prepared. That is, the cuff includes slip sensors 15a and 15b and a force sensor 14 as shown in FIGS. The cuffs 12a and 12b may be removed from the wearable movement assist device 1 for use. The cuff is attached to a prosthesis and connected to a manipulator so that the position of the cuff can be moved. The artificial limb surface is covered with artificial skin. This artificial skin is very similar to the slip characteristics of actual skin.

  Next, the movement of the foot 2 of the human body is imitated by applying a force to the cuff by operating the manipulator based on the slip amount, slip speed, force, and moment values recorded in the storage device. When the movement amount of the cuffs 12a and 12b is measured using motion capture, the value may be taken into consideration. This imitated motion is repeated a plurality of times, and during that time, the slip sensor 15a, 15b and force sensor 14 provided in the cuff measure the amount of slip, the slip speed, the force and the moment in the translational and rotational directions of the prosthesis with respect to the cuff. .

  The wound risk of skin is evaluated using the values of slip amount, slip speed, force and moment of the prosthesis with respect to the cuff thus measured. And based on the evaluation, by changing the shape, the mounting position, the material, the fastening method at the time of mounting, and the like of the actual cuff 12a, b, it is possible to prevent the wound of the mounting portion of the cuff 12a, b.

  Since this wound risk evaluation method can evaluate the wound risk without imposing a load on the human body, it is highly safe and can be easily evaluated.

  In addition, although the wearing type movement assistance apparatus 1 of Example 1 was mounted | worn on the leg of a human body and supported the movement of a knee, the wearing type movement assistance apparatus of this invention is restricted to what is mounted | worn to a knee part. Absent. For example, it may be a wearable movement assist device that supports movement of arms, shoulders, waist, fingers, and the like. Further, it may support movements at a plurality of locations (for example, movements of legs and hips) or may support the whole body.

  In addition, the wearable movement assist device of the present invention can be used not only for evaluation of wound risk but also for warning of wound risk. For example, a warning sound can be generated when the wound risk exceeds a predetermined reference value due to the operation of the wearable motion assisting device.

  According to the present invention, since the wound risk of the wearable movement assist device can be easily evaluated, a highly safe wearable movement assist device can be realized at low cost.

1: Wearable motion assist device 2: Foot 10a, b: Link 11: Drive unit 12a, b: Cuff 14: Force sensor 15: Slip sensor package 15a, b: Slip sensor 150: Substrate 151: Light emitting device 152 : Lens 153: Image sensor

Claims (6)

In a measuring device that contacts the human body and prosthetic limbs and measures the relative sliding amount, sliding speed, and force and moment from the human body and prosthetic limbs,
A contact part to be worn in contact with the human body and a prosthesis
Two slip sensors provided at a distance from each other to measure a sliding amount and a sliding speed of a human body and a prosthetic limb with respect to the contact portion in the contact portion,
A force sensor for measuring the force and moment from the human body and prosthetic limbs in the contact portion;
Have
The slip sensor is
A light emitting device that emits light to the human body and the prosthetic limbs;
An image sensor that receives light reflected by a human body or a prosthesis to acquire an image, and calculates the slip amount and the slip speed from a temporal change of the image, and
A slip amount and a slip speed about a rotation axis perpendicular to a plane formed by two slip directions are calculated from the slip amount and the slip speed measured by the two slip sensors.
A measuring device characterized by that.   The measuring apparatus according to claim 1, wherein the two slip sensors are provided to face each other across an action point of the force sensor.   2. The force sensor according to claim 1, wherein the force sensor is a sensor that detects at least three components of a force component in a biaxial direction orthogonal to the contact plane and a moment component around an axis orthogonal to the two axes. Item 3. The measuring apparatus according to any one of Items 2 above. The measurement device according to any one of claims 1 to 3, wherein the measurement device is connected to the drive unit via a drive unit and a link.
A wearable motion assisting device characterized by comprising:   The wearable motion assisting device according to claim 4, wherein the two slip sensors are provided so as to face each other in a longitudinal direction of the link. The wearable movement assist device according to claim 5 is operated by being worn on a human body,
By the slip sensor and the force sensor of the wearable movement assist device, the amount of slip, the slip speed, and the force and moment of the human body with respect to the contact part in the contact part are measured,
The measurement device according to claim 1 is attached to a manipulator, the contact portion of the measurement device is attached to a prosthesis,
By controlling the manipulator based on the measured sliding amount, sliding speed, force, and moment value, and operating the contact portion, imitating the operation of the contact portion during human movement,
Measure the amount of sliding, sliding speed, force, and moment during this imitation operation, and evaluate the wound risk from the measured values.
A wound risk evaluation method for a wearable motion assist device.

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