JP6968351B2 - Load measuring device, caregiving device, load measuring method, and load measuring program - Google Patents

Description

The present invention relates to a load measuring device, an assisting device, a load measuring method, and a load measuring program.

There is a device that calculates the load on the waist of the person to be measured and generates a warning sound when a large load occurs (see, for example, Patent Document 1).
[Patent Document] Japanese Unexamined Patent Publication No. 2012-183291

In order to improve the load calculation accuracy, a large number of sensors and a processing device that executes high-speed processing had to be used, which was not suitable for use in the field such as nursing care work.

In the first aspect of the present invention, a first measuring unit that measures a first physical quantity that reflects the posture of the upper body of the person to be measured, and a second measuring unit that reflects the degree of muscle tension that maintains the posture. A load measuring device including a second measuring unit for measuring a physical quantity and a calculating unit for calculating a value of a load applied to the waist of a person to be measured based on the first physical quantity and the second physical quantity is provided.

In the second aspect of the present invention, there is provided a caregiving device including the above-mentioned measuring device and a driving unit that generates a driving force to reduce the load according to the value of the load calculated by the calculation unit.

In the third aspect of the present invention, a first measurement step of measuring a first physical quantity reflecting the posture of the upper body of the person to be measured and a second measuring step reflecting the degree of muscle tension to maintain the posture are reflected. A load measuring method including a second measuring step of measuring a physical quantity and a calculation step of calculating a value of a load applied to the waist of a person to be measured based on the first physical quantity and the second physical quantity is provided.

In the fourth aspect of the present invention, the first acquisition step of acquiring the first physical quantity reflecting the posture of the upper body of the subject and the second acquisition of the tension of the muscles maintaining the posture are reflected. Load measurement that causes the computer to execute a second acquisition step for acquiring a physical quantity and a calculation step for calculating the value of the load applied to the lumbar spine of the subject based on the acquired first physical quantity and the second physical quantity. The program is provided.

The outline of the above invention is not a list of all the features of the present invention. Sub-combinations of these features can also be inventions.

It is a schematic diagram of the caregiving device 110. It is a block diagram of the care device 110 including the measuring device 111. It is a flow chart which shows the execution procedure of the process in the measuring apparatus 111. It is a figure which shows typically the operation of the subject 130. It is a figure which shows the physical model 200 of the waist part. It is a graph which shows the measured value of the lumbar load applied to the person to be measured 130. It is a figure which shows typically the operation of the subject 130. It is a graph which evaluates the calculated value by the measuring apparatus 111. It is a figure which shows the link model at the time of introducing the movement of the center of gravity by a load. It is a graph which evaluates the calculated value by the measuring apparatus 111. It is a table which shows the evaluation result of the calculated value by the measuring apparatus 111. It is a graph which shows the evaluation result of the calculated value by the measuring apparatus 111.

Hereinafter, the present invention will be described through embodiments of the invention. The following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are essential for the means of solving the invention.

The measuring device 111 according to this embodiment measures a physical quantity that reflects the posture of the upper body of the subject 130 and a physical quantity that reflects the degree of muscle tension that maintains the posture, and is a value of the load applied to the subject. Is calculated. The physical quantity that reflects the posture of the upper body means a value that reflects the posture such as tilting and turning of the upper body. The physical quantity that reflects the tilted posture of the upper body refers to the angle of the spine with respect to the ground due to the flexion of the waist.

The angle of the spine with respect to the ground can be measured using the center line where the coronal plane and the sagittal plane intersect as an index, and can be simply measured by an acceleration sensor or the like mounted on the back of the subject. The physical quantity reflecting the turning posture of the upper body means the rotation angle of the coronal plane or the sagittal plane, and can be similarly measured by an acceleration sensor or the like mounted on the back of the person to be measured.

The muscles that maintain posture are the trunk muscles. If it is possible to measure a value that reflects the degree of tension in a part of the posterior trunk muscle or the anterior trunk muscle among the trunk muscles, it is possible to calculate the value of the burden on the subject. Of the trunk muscles, the anterior trunk muscle is easily affected by wearing a measuring device, so it is preferable to measure a value that reflects the degree of tension of the posterior trunk muscle.

When measuring the posterior trunk muscle, it is preferable to measure a value that reflects the degree of tension of any of the so-called "latissimus dorsi muscle", the erector spinae muscle, and the trapezius muscle. When measuring the anterior trunk muscles, it is best to measure the so-called "abdominal muscles" that reflect the degree of tension in any of the rectus abdominis, transverse abdominis, and oblique abdominal muscles. preferable. The latissimus dorsi muscle, the erector spinae muscle, and the trapezius muscle are collectively referred to as the back muscle group. The rectus abdominis muscle, transverse abdominal muscle, and oblique abdominal muscle are collectively called the abdominal muscle group.

However, it is difficult to directly measure the muscle strength F generated by the active muscle of the subject to be measured. Therefore, as an index of the muscle strength exerted by the person to be measured, a physical quantity reflecting the degree of muscle tension can be acquired, and the muscle strength F can be calculated based on the acquired physical quantity. This makes it possible to relatively easily measure the muscle strength generated by the muscle of the person to be measured during activity. Here, the physical quantity that reflects the degree of muscle tension can be measured, for example, as the hardness of the muscle.

In the present embodiment, the muscle hardness (hereinafter, also referred to as “muscle hardness”) refers to a numerical value that is an index of muscle hardness, and specifically, the body surface portion of the muscle portion to be measured. A load cell or the like is installed so as to be in contact with the load cell or the like, and the value is measured as a force value (N) by the load cell or the like. Since the load cell outputs the value of the load generated based on wearing (pressure required for wearing, etc.) even in a stationary state, the muscle hardness is a value measured when the muscle is not loaded at rest, etc. May be used as a reference value, and a value obtained by calculating the difference between the measured value and the reference value may be used.

FIG. 1 is a schematic view of an assisting device 110 including a measuring device 111 according to an embodiment, in which the assisting device 110 is attached and a person to be measured 130 to be measured by the measuring device 111 is viewed from the back side. Is shown. As shown by an arrow in the lower right of the figure, in the following description, the right hand side of the measured person 130 is on the right, the left hand side of the measured person 130 is on the left, and the head side of the measured person 130 is on the top. The foot side of the person to be measured 130 is described as below. Further, the direction in which the front surface of the body of the person to be measured 130 faces may be described as the front, and the direction in which the back surface of the person to be measured 130 faces and the rear may be described.

When viewed from the back side of the person to be measured 130, the measuring device 111 mounted on the person to be measured 130 includes a wearing part 112, a support part 122, a belt part 124, and a measuring part 118. The measuring unit 118 includes a right side pressure sensor 125, a left side pressure sensor 128, a lower acceleration sensor 127, an upper acceleration sensor 129, and a calculation unit 146. The right side pressure sensor 125 and the left side pressure sensor 128 correspond to the muscle hardness measuring unit 162 described later. The lower accelerometer 127 and the upper accelerometer 129 correspond to the upper body inclination measuring unit 161 described later.

As shown in FIG. 1, the wearing portion 112 is, for example, a bodysuit-like garment formed of elastic fabric, which is attached to at least the upper body of the person to be measured 130. Many elements of the measuring device 111 are attached to the wearing portion 112, and when the person to be measured 130 wears the wearing part 112, the person to be measured 130 becomes a measurement target of the measuring device 111.

The support portion 122 is made of a material having elasticity but higher rigidity than the wearing portion 112, for example, resin, metal, or the like, and is integrally attached to the wearing portion 112, for example. The support portion 122 is located around the waist to the abdomen of the person to be measured 130 when the person to be measured 130 wears the measuring device 111.

The belt portion 124 is integrally formed with the wearing portion 112 and is arranged around the waist portion of the person to be measured 130 wearing the measuring device 111. The belt portion 124 prevents the wearing portion 112 from sliding down with respect to the body of the person to be measured 130.

Each of the right side pressure sensor 125 and the left side pressure sensor 128 has, for example, a load cell that changes the output voltage according to the magnitude of the applied pressure when pressurized. Further, the right side pressure sensor 125 and the left side pressure sensor 128 are sandwiched between the body surface of the person to be measured 130 and the support portion 122.

Further, the right side pressure sensor 125 and the left side pressure sensor 128 are arranged at positions overlapping with any one of the back muscles of the back muscle group of the subject 130. In FIG. 1, it is arranged at a position overlapping the erector spinae muscles. As a result, when the hardness of the back muscle group of the subject 130 changes with the flexion of the waist, the right side pressure sensor 125 and the left side pressure sensor 128 change the output voltage according to the change in the muscle hardness. ..

The lower accelerometer 127 and the upper accelerometer 129 are attached to the person to be measured 130 in a state of being fixed to the wearing portion 112. Therefore, when the body surface of the person to be measured 130 is displaced at the position where the lower acceleration sensor 127 and the upper acceleration sensor 129 are arranged, the acceleration accompanying the displacement is detected by the lower acceleration sensor 127 or the upper acceleration sensor 129.

Further, the lower acceleration sensor 127 and the upper acceleration sensor 129 are, for example, 3-axis sensors, and detect not only the acceleration due to the displacement in the horizontal direction but also the acceleration in the gravity direction. Thereby, in addition to the acceleration caused by the displacement of the subject 130 in the horizontal direction, the acceleration caused by the displacement in the height direction of the waist caused when the subject 130 bends and stretches can be detected.

The lower accelerometer 127 is arranged near the sacrum of the subject 130. The vicinity of the sacrum means the position on the epidermis where the normal extending from the epidermis of the subject 130 reaches the sacrum. Further, the upper acceleration sensor 129 is arranged near the upper end of the wearing portion 112 on the back of the person to be measured 130.

The sacrum is in a position where horizontal displacement is unlikely to occur unless the entire subject 130 moves. On the other hand, the upper part of the back of the person to be measured 130 is a position where the person to be measured 130 is greatly displaced when the inclination of the upper body of the person to be measured changes. Therefore, by calculating the difference between the detected value of the lower acceleration sensor 127 and the detected value of the upper acceleration sensor 129, the inclination of the upper body of the person to be measured 130 can be detected.

The calculation unit 146 acquires the physical amount of pressure or acceleration by each of the right side pressure sensor 125, the left side pressure sensor 128, the lower acceleration sensor 127, and the upper acceleration sensor 129, and calculates the load applied to the waist of the person to be measured 130. The calculated load value is displayed as a physical quantity, for example, to the manager who manages the load applied to the person to be measured 130. In this case, the calculation unit 146 may transmit the calculated load value to a display device that can be visually recognized by the administrator, for example, a terminal device using a general-purpose information processing device such as a personal computer, via a wired or wireless line.

Further, the physical quantity display format may display the physical quantity itself as a numerical value, or may be an alarm indicating that the physical quantity exceeding a predetermined threshold value has been calculated. The alarm may be a lamp, a buzzer, a voice, or the like, as well as a method of displaying the alarm on the display device of the information processing device by characters, figures, or the like. Further, a display unit or an alarm unit worn by the person to be measured 130 may be provided to notify the person to be measured 130 of the physical quantity.

Further, in the calculation unit 146, when the care device 110 attached to the person to be measured 130 for the purpose of reducing the load on the lumbar region of the person to be measured 130 controls the actuator 114 that generates an auxiliary force acting on the person to be measured 130. In addition, the assist device 110 may refer to the calculated physical quantity of the lumbar load. As a result, the actuator 114 can generate a force for canceling the load with a strength corresponding to the load applied to the waist of the person to be measured 130, and the care device 110 can be operated efficiently.

The caregiving device 110 shares the wearing part 112, the support part 122, and the belt part 124 with the measuring device 111, and further includes an actuator 114 and a driving part 116. The actuator 114 and the drive unit 116 operate with reference to the physical quantity output by the measuring device 111.

The actuator 114 is arranged in the left-right direction on the back surface side of the person to be measured 130 and on the surface of the cloth wearing portion 112 on the side not in contact with the person to be measured 130. Further, the actuator 114 is attached to the wearing portion 112 over the entire length and is in close contact with the body of the person to be measured 130 together with the wearing portion 112.

Actuator 114 converts the input energy into physical motion. The actuator 114 includes a drive device that converts energy into translational or rotational motion by means of a hydraulic system, an electric motor, an electromagnet, or the like. The actuator 114 also includes a polymer material such as a dielectric elastomer that expands and contracts when the applied voltage changes. The dielectric elastomer expands in the longitudinal direction when the applied voltage increases, and contracts in the longitudinal direction when the applied voltage decreases. As a result, the tightening force on the waist of the person to be measured 130 is changed, and the degree of assistance to the waist of the person to be measured 130 is changed.

The drive unit 116 refers to the physical quantity of the measuring device 111 and controls the electric power supplied to the actuator 114 according to the magnitude of the load applied to the person to be measured 130. The actuator 114 changes the presence / absence and magnitude of an auxiliary force generated by the electric power supplied from the drive unit 116.

As a result, the actuator 114 reduces the load on the waist with an auxiliary force according to the magnitude of the load applied to the waist of the person to be measured 130. Further, when the load is not generated on the lumbar region, the tightening by the actuator 114 is released, so that the burden on the person to be measured 130 is reduced and the power of the assist device 110 is saved.

FIG. 2 is a block diagram of the entire system including the care device 110. The system includes a caregiving device 110, which includes a drive unit 116, an actuator 114, and a measuring device 111. Further, the measuring device 111 includes a measuring unit 118 and a calculating unit 146. Further, this system includes a server 133 and a terminal device 126 outside the care device 110, and the care device 110, the server 133, and the terminal device 126 are connected to each other through a communication line 132.

The measuring unit 118 of the measuring device 111 has an upper body inclination measuring unit 161 as a first measuring unit and a muscle hardness measuring unit 162 as a second measuring unit. The upper body inclination measuring unit 161 measures, for example, based on the difference between the measured value of the upper acceleration sensor 129 and the measured value of the lower acceleration sensor 127, and reflects the inclination of the upper body of the person to be measured 130 equipped with the assistance device 110. The value is acquired by the calculation unit 146.

The muscle hardness measuring unit 162, for example, is based on the average value of the measured value of the right side pressure sensor 125 and the measured value of the left side pressure sensor 128, and the muscle hardness measuring unit 162 is the hardness of the back muscle group 220 of the person to be measured 130 wearing the assistance device 110. The calculation unit 146 is made to acquire the measured value reflecting the above.

The calculation unit 146 has a storage unit 148, a measured value acquisition unit 150, and a lumbar load calculation unit 152. The storage unit 148 stores the values of the parameters used in the calculation for calculating the load applied to the lumbar region. Further, the storage unit 148 may store a look-up table or the like showing the relationship between the lumbar load value and the drive voltage applied to the actuator, which is used when controlling the actuator 114. The storage unit 148 may be built in the calculation unit 146 worn by the person to be measured 130, or may be arranged at a position away from the person to be measured 130.

The measured value acquisition unit 150 acquires the measured value used when calculating the load applied to the waist of the person to be measured 130 from the measurement unit 118. In this embodiment, as the first measured value, the measured value reflecting the inclination of the upper body of the person to be measured 130 is acquired. Further, as the second measured value, a physical quantity reflecting the hardness of the back muscle group of the subject 130 is acquired.

The lumbar load calculation unit 152 calculates the value of the load applied to the waist of the person to be measured 130 based on the measured value acquired by the measured value acquisition unit 150. In calculating the load applied to the waist of the person to be measured 130, the waist load calculation unit 152 may refer to the parameters stored in the storage unit 148.

The parameters include information on mathematical formulas described later, information on the body such as the height and weight of the person to be measured, reference values caused by individual differences in the body of the person to be measured, and reference values at rest of the person to be measured. Information etc. are included. Further, the lumbar load calculation unit 152 calculates the driving force to be supplied to the actuator 114, for example, the amount of electric power, according to the magnitude of the lumbar load value with respect to the calculated lumbar load value of the person to be measured 130. Then, the drive unit 116 may be notified.

Further, the lumbar load calculation unit 152 may warn the notification unit 140 that an alarm should be notified when the calculated value of each waist load exceeds a predetermined threshold value. Further, the lumbar load calculation unit 152 may display the display unit 142 in a posture in which the load applied to the lumbar region is reduced when the calculated load applied to each lumbar region exceeds a predetermined threshold value. ..

The drive unit 116 controls the actuator 114 based on the lumbar load value calculated by the lumbar load calculation unit 152. For example, the drive unit 116 acquires an applied voltage value corresponding to the load applied to the lumbar region from the lumbar load calculation unit 152, and applies a voltage corresponding to the acquired applied voltage value to the actuator 114. As a result, the actuator 114 rotates or expands and contracts to tighten the lumbar portion of the person to be measured 130 with the tightening force according to the lumbar load calculated by the lumbar load calculation unit 152.

The terminal device 126 is connected to the above-mentioned care device 110 through a communication line 132 such as LAN, the Internet, and Bluetooth (registered trademark). In the illustrated example, the terminal device 126 communicates with at least the drive unit 116, the calculation unit 146, and the like.

The terminal device 126 has a notification unit 140, a display unit 142, and an input unit 144. The input unit 144 receives the instruction of the administrator 131 to the care device 110. Further, the input unit 144 accepts an input from the person to be measured 130, for example, an input such as the weight of the person to be measured 130.

The notification unit 140 conveys a notification, an alarm, an operating state, a charging state, and the like from the care device 110 to the administrator 131. The display unit 142 displays information on the waist load of the person to be measured 130 measured by the measuring device 111, and conveys the information to the manager 131. The notification unit 140 informs the manager 131 that, for example, the physical quantity by the measuring device 111 exceeds a predetermined threshold value by sound, light, electrical stimulation, or the like. As a result, the manager 131 can monitor the lumbar load applied to the person to be measured 130 at a place away from the person to be measured 130.

The terminal device 126 can be formed by using a general-purpose information processing device, for example, a personal computer. Further, as the terminal device 126, a mobile information terminal such as a smartphone or a tablet may be used.

Further, the person to be measured 130 may wear the notification unit 140, the display unit 142, and the input unit 144, and the person to be measured 130 may use the assist device 110 standalone. Further, at least a part of the notification unit 140, the display unit 142, and the input unit 144 may be attached to the person to be measured 130 and operated in parallel with the terminal device 126.

Further, in the above example, the calculation unit 146 is carried by the person to be measured 130 integrally with the measurement unit 118. However, at least a part of the calculation unit 146 may be distributed to the server 133 via the communication line 132. This makes it possible to execute the process of calculating the lumbar load value with a processing device having a larger processing capacity.

FIG. 3 is a flow chart showing a procedure of processing executed by the caregiving device 110 measuring device 111. When receiving an instruction from the outside, or at a predetermined time or a preset time interval, the measuring device 111 starts measuring the load applied to the waist of the person to be measured 130 by the measuring device 111.

When the measurement of the waist load is started, the measuring device 111 first determines the inclination of the upper body of the subject 130 based on the difference between the acceleration measured by the upper acceleration sensor 129 and the acceleration measured by the lower acceleration sensor 127. Measure (step S101). Further, the measuring device 111 calculates the average of the physical quantity of the right side pressure sensor 125 and the physical quantity of the left side pressure sensor 128 to measure the muscle hardness of the back muscle group of the subject 130 (step S102).

The inclination measurement (step S101) and the muscle hardness measurement (step S102) may be performed simultaneously or sequentially if the time interval is short. Further, the order of step S101 and step S102 may be reversed.

Next, the measuring device 111 causes the calculation unit 146 to acquire the measured value measured by the measuring unit 118 (step S103). That is, the measured value of the upper body inclination measuring unit 161 including the upper acceleration sensor 129 and the lower acceleration sensor 127 is acquired by the measured value acquisition unit of the calculation unit 146. Further, the measured value of the muscle hardness measuring unit 162 including the right side pressure sensor 125 and the left side pressure sensor 128 is acquired by the measured value acquisition unit 150 of the calculation unit 146.

Next, the measuring device 111 causes the waist load calculation unit 152 of the calculation unit 146 to calculate the load applied to the waist of the person to be measured 130 using the acquired measured value (step S104). The lumbar load calculation unit 152 calculates the magnitude of the load applied to the lumbar region of the person to be measured 130 with reference to the parameters acquired from the storage unit. The contents of the calculation process executed here will be described later.

Next, the measuring device 111 causes the drive unit 116, the terminal device 126, and the like to transmit the value of the lumbar load calculated by the calculation unit 146 (step S105), and ends the process. Here, the calculation of the lumbar load executed in step S104 will be described.

FIG. 4 is a diagram schematically showing the operation of the person to be measured 130 in which a load applied to the lumbar region is generated. From the state (1) in which the subject 130 is upright in the order of the numbers 1 to 3 shown in the figure, the hand is brought closer to the floor by the action of bending the waist (2) (3), and then the waist is stretched (4). ) During (5) until the upper body is raised and finally returned to the upright state, the value of the waist load generated by the mass of the upper body of the subject 130 itself acting on the waist changes.

FIG. 5 is a diagram showing a physical model 200 around the lumbar spine when the lumbar load of the subject 130 changes as described above. The lumbar vertebra 240 has vertebrae 241 and 242, 243, 244, and 245 rotatably connected to each other. In this physical model 200, the entire lumbar spine 240 may be regarded as a rigid body.

The lower end of the lumbar spine 240 is rotatably supported with respect to the sacrum 250. The upper end of the lumbar 240, the lower end of the thoracic spine 210, for rotatably supporting a rotational angle phi _7. Regarded This physical model 200, before and after lumbar 240, and strength F _A which abdominal group 230 occurs, and the strength F _B of back muscles 220 occurs, the balanced statically at each stage of motion shown in FIG. 4 vinegar.

Note that the measurement portion 118 of the assistance device 110 is provided with the right pressure sensor 125 and the left pressure sensor 128, and hardness P _R muscles of the right back muscles against lumbar 240, the left back muscles of the hardness P _L of the muscle has been measured separately. However, in the following calculations, the average value P _S calculated according to Equation 1 below, handled as a value reflecting the degree of back muscles 220 overall tension. Incidentally, when considering the load on the when the upper body of the subject 130 is rotated in the spine around the waist treats the left and right pressure P _R, the P _L individually.

Been thoracic 210 supported on lumbar 240, if the back muscles 220 contracted in the back side of the lumbar 240 has generated the strength _{F B,} rotation moment _l m6 · _{F B} acts, the back side of the subject 130 Lean to. Further, thoracic 210, if the abdominal muscle group 230 contracted with the front side of the lumbar 240 has generated the strength _{F A,} rotational moment _l n6 · _{F A} is inclined to the front side of the subject 130 acts. The slope of such a thoracic 210, slope upper body of the subject 130, the lumbar 240, the load _{f 7} acts. Here, the rotation angle of the thoracic spine 210 by the action of back muscles 220 or abdominal group 230 and phi _7.

上式において、Ｍは、被測定者１３０の上体の質量を表し、ｇは重力加速度を表す。被測定者１３０の上体の質量は、例えば、被測定者１３０の全質量の６０％程度であることから、予め被測定者１３０の体重を測定して格納部１４８に格納しておき、腰部負荷算出部１５２に参照させてもよい。Analyzing the load applied to the lumbar spine of the subject 130 according to the above physical model 200, the balance shown in the following equation 2 is established around the lumbar spine 240.

In the above equation, M represents the mass of the upper body of the subject 130, and g represents the gravitational acceleration. Since the mass of the upper body of the person to be measured 130 is, for example, about 60% of the total mass of the person to be measured 130, the weight of the person to be measured 130 is measured in advance and stored in the storage unit 148, and the waist portion. It may be referred to by the load calculation unit 152.

Moreover, the sacrum 250 side, the rotation moment _F A _{l n0} muscle _{F A} which abdominal group 230 exerts, since a rotation moment _F B _{l m0} muscle _{F B} of back muscles 220 exerts is balanced, Equation 3 below Is established.

Moreover, the load F applied to the lumbar spine 240 may be strength _F A, using the _{F B} expressed by the equation 4 below.

Here, the gain of the muscle hardness measuring unit 162 is set to α based on the forward bending motion (see FIG. 4) performed by the person to be measured 130 without applying a load, that is, without carrying a load. , the offset of strength F _B beta, the sensor value offset of the right pressure sensor 125 and left pressure sensors 128 as C, employing a formula 5 and 6 below as the estimated equation.

FIG. 6 is a graph showing the measured values of the load applied to the lumbar region when the operation shown in FIG. 4 is executed without the additional load on the person to be measured 130. Based on the values shown in FIG. 6, the values of the parameters α, β, and C in the above estimation formula (Equation 5) were determined. The values of the determined parameters are stored in the storage unit 148 and referred to when estimating the load during operation of the person to be measured by using the estimation formulas (formulas 5 and 6).

In this way, in the measuring device 111 of the caregiving device 110, two measured values of the inclination of the upper body of the person to be measured 130 and the hardness of the muscles of the back muscle group of the person to be measured 130 are measured, and the person to be measured The load applied to the lumbar vertebra 240 as an example of the load applied to the lumbar region of 130 can be calculated. Since both of the two measured values can be measured from outside the body of the person to be measured 130 with a simple sensor, the caregiving device 110 provided with the measuring device 111 is highly productive and easy to operate.

FIG. 7 is a diagram schematically showing the operation of the subject 130 in which the load applied to the lumbar region changes by holding the load 134 in the hand and bending and stretching the lumbar region. That is, the person to be measured 130 who initially holds the load 134 in a substantially upright position (1) bends his hips to lower the load 134 (2), and further bends his hips to lower the load 134 to near the floor. After that (3), the operation until the waist is stretched, the load 134 is lifted (4), and finally the state of standing upright is returned (5) is shown. In such a series of operations, a load caused by both the mass of the upper body of the person to be measured 130 and the load held by the person to be measured 130 acts on the waist of the person to be measured 130.

FIG. 8 is a graph for evaluating the calculation result by the measuring device 111. The illustrated graph shows, over time, the change in load on the lumbar region that occurs when the subject 130 performs the series of movements shown in FIG. 7 for a load of 15 kg. In the figure, in addition to the value of the lumbar load measured by the measuring device 111 described so far, the value of the load calculated in consideration of the mass and position of the upper arm (hereinafter referred to as “control value”) and the subject. The value of the lumbar load calculated based only on the inclination of the upper body of the measurer 130 and the value calculated by introducing the measurement result of the muscle hardness are shown together.

As shown in the figure, when the lumbar load is calculated based only on the inclination of the upper body of the subject 130 without a sensor for measuring the hardness of the muscle, the change is similar to the control value as a whole, but the calculation is performed. The value of the load to be applied changes to a low value. On the other hand, the lumbar load value calculated by introducing the measured value of muscle hardness shows a value closer to the control value.

When calculating the lumbar load based only on the inclination of the upper body of the subject 130 without using the sensor for measuring the muscle hardness, the lumbar region is calculated using the above equations 2, 3, and 4. Calculate the load value.

As described above, the value of the waist load of the subject calculated based on the muscle hardness is close to the value of the load with higher accuracy calculated in consideration of the movement of the center of gravity. However, in order to introduce the movement of the center of gravity into the calculation of the load value, information on the mass of the load and the distance between the center of gravity of the person to be measured and the center of gravity of the load is required each time, and the person to be measured is active. Obtaining such information from 130 is not practical. Further, the measuring device capable of acquiring such information has a large device configuration, and the burden on the person to be measured 130 who holds the load increases.

In other words, by calculating based on the muscle hardness of the person to be measured 130, the value of the lumbar load can be accurately measured without considering the movement of the center of gravity due to the additional load. Can be simplified. In particular, when the hardness of the back muscle group is used as an index, the device can be centrally arranged on the back of the person to be measured, so that the measuring device 111 can be miniaturized.

Further, together with the measuring device 111, an assisting device 110 including an actuator 114 and a driving unit 116 is formed on the back surface of the person to be measured 130. Although the calculation unit 146 and the drive unit 116 are individually provided in FIG. 1, the assistance device 110 including the measurement device 111 can be further miniaturized by integrally forming them.

FIG. 10 is a graph showing the evaluation results when the magnitude of the load applied to the subject 130 is changed to 5 kg, 10 kg, and 15 kg, and the same evaluation is performed for three subjects. The average error value is the absolute value of the difference between the load value calculated using the measured value of the muscle hardness sensor in the present embodiment and the load value calculated without using the muscle hardness sensor as a comparative example and the control value. Represents the average value of. Further, FIG. 11 is a table showing the evaluation results shown in FIG. 10 individually for each subject by converting them into the improvement rate due to the introduction of the measured value of the muscle hardness. Further, FIG. 12 is a graph showing the error of the physical quantity and the improvement rate by introducing the measured value of the muscle hardness by the average value of all the subjects.

As shown in each figure, by introducing the measured value of muscle hardness into the calculation of the lumbar load, the error may be reduced but not increased. Of the subjects shown in FIG. 10, subject 3 is also a subject when the data shown in FIG. 8 is measured.

As described above, the caregiving device 110 that drives the actuator 114 to the drive unit 116 according to the value calculated by the measuring device 111 can efficiently reduce the load applied to the waist portion of the person to be measured 130. Further, when the load applied to the waist of the person to be measured 130 is small, the assisting force of the assist device 110 is also low, so that it is possible to prevent the person to be measured 130 from being unnecessarily burdened.

In the above example, the estimation formula was constructed with the entire lumbar spine 240 as a rigid body. However, after calculating the load applied to the entire lumbar vertebra 240, it is also possible to further calculate the load applied individually to the five vertebrae 241 and 242, 243, 244, 245 forming the lumbar vertebra 240. For example, the measuring device 111 is provided with a sensor that detects the curve drawn by the lumbar spine when the subject 130 bends the waist, and distributes the load applied to the entire lumbar spine 240 to each of the vertebrae 241 and 242, 243, 244, and 245. There is a way to do it.

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various changes or improvements can be made to the above embodiments. It is also clear from the claims that modified or modified forms may also be included in the technical scope of the invention.

The order of execution of each process such as operation, procedure, step, and stage in the device, system, program, and method shown in the claims, description, and drawings is particularly "before" and "prior". It should be noted that it can be realized in any order as long as the output of the previous process is not used in the subsequent process. Even if the claims, the description, and the operation flow in the drawings are explained using "first", "next", etc. for convenience, it does not necessarily mean that it is essential to carry out in this order. ..

110 Assistance device, 111 measuring device, 112 wearing part, 114 actuator, 116 drive part, 118 measuring part, 122 support part, 124 belt part, 125 right side pressure sensor, 126 terminal device, 127 lower acceleration sensor, 128 left side pressure sensor, 129 Upper acceleration sensor, 130 Measured person, 131 administrator, 132 communication line, 133 server, 134 load, 140 notification unit, 142 display unit, 144 input unit, 146 calculation unit, 148 storage unit, 150 measurement value acquisition unit, 152 Lumbar load calculation unit, 161 Upper body inclination measurement unit, 162 Muscle stiffness measurement unit, 200 Physical model, 210 Chest spine, 220 Back muscle group, 230 Abdominal muscle group, 240 Lumbar spine, 241 242, 243, 244, 245 vertebral bone, 250 sacrum

Claims (12)

A first measuring unit that measures at least one of the inclination or the angle of rotation of the upper body, which is a first physical quantity that reflects the posture of the upper body of the person to be measured.
A second measuring unit for measuring the hardness of the muscle, which is a second physical quantity that reflects the degree of tension of at least one of the posterior trunk muscle and the anterior trunk muscle, which are the muscles that maintain the posture.
A load measuring device including a calculation unit that calculates a value of a load applied to the waist of the person to be measured based on the first physical quantity and the second physical quantity. The load measuring device according to claim 1 , wherein the second measuring unit measures a force generated on the waist. The load measuring device according to claim 1 or 2 , wherein the first measuring unit includes an acceleration sensor that is displaced according to a change in the inclination of the upper body. The calculation unit is described in any one of claims 1 to 3 for calculating the value of the load by using a value reflecting the degree of tension of other muscles, which is balanced with the second physical quantity. Load measuring device. The calculation unit according to any one of claims 1 to 4 , which holds a default value reflecting the weight of the upper body in advance and refers to the default value when calculating the load value. Load measuring device. The calculation unit uses a value of the load for the entire lumbar calculated from the first physical quantity and the second physical quantity, according to claim 1 for calculating individual values of the load for each of the vertebrae forming the lumbar The load measuring device according to any one of 5 to 5. The load measuring device according to claim 6 , further comprising a third measuring unit for measuring a third physical quantity reflecting the displacement of the lumbar spine of the person to be measured. The third measuring unit measures the change in the difference between the horizontal position of the upper end of the lumbar spine and the horizontal position of the lower end of the lumbar spine of the subject.
The load measuring device according to claim 7 , wherein the calculation unit calculates the value of the load for each of the vertebrae by using the change of the difference. The load measuring device according to any one of claims 1 to 8 , further comprising an alarm unit that generates a warning to the outside when the calculation unit calculates a value of the load exceeding a predetermined threshold value. .. The load measuring device according to any one of claims 1 to 9.
A caregiving device including a drive unit that generates a drive force for reducing the load on the actuator based on the load value calculated by the calculation unit. A first measurement step of measuring at least one of the inclination or the angle of rotation of the upper body, which is a first physical quantity reflecting the posture of the upper body of the person to be measured, and
A second measurement step of measuring the hardness of the muscle, which is a second physical quantity that reflects the degree of tension of at least one of the posterior trunk muscle and the anterior trunk muscle, which are the muscles that maintain the posture, and the second measurement step.
A load measuring method including a calculation step of calculating a value of a load applied to the waist of a person to be measured based on the first physical quantity and the second physical quantity. The first acquisition step of acquiring at least one of the inclination or the angle of rotation of the upper body, which is the first physical quantity reflecting the posture of the upper body of the person to be measured, and
A second acquisition step of acquiring the hardness of the muscle, which is a second physical quantity that reflects the degree of tension of at least one of the posterior trunk muscle and the anterior trunk muscle, which are the muscles that maintain the posture.
A load measurement program for causing a computer to perform a calculation step of calculating a value of a load applied to the waist of a person to be measured based on the acquired first physical quantity and the second physical quantity.

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