JP2020067384A - Load detector and calibration device for load detector - Google Patents

Abstract

To provide a load detector that is capable of easily performing calibration.SOLUTION: A load detector 100a for detecting a load due to a subject on a bed comprises: a strain body comprising a free end; a support part for supporting the strain body; a mounting part 3 which is coupled to the free end of the strain body and on which the bed is mounted; a deformation sensor which is attached to the strain body; and a calibration unit 4 for calibrating the load detector. The calibration unit comprises: a load application unit 40 for applying a calibration load to the free end of the strain body; and an adjustment unit 43 for adjusting a magnitude of the calibration load which is applied to the free end of the strain body by the load application unit.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a load detector including a calibration unit and a load detector calibration apparatus.

  In hospitals and nursing facilities, the load applied to the bed is detected by the load detector, and based on the detected load, it is determined whether there are patients or residents on the bed (bed / bed determination). It is known to perform or obtain information such as respiratory rate regarding the patient or resident on the bed.

  Patent Literature 1 discloses a bed apparatus including a bed leaving prediction / detection system, and the apparatus includes a load measuring unit that detects a load of the bed and generates a load signal.

Japanese Patent No. 4514717

  It is desirable to calibrate the installed load detection value when the load detector is installed or at a predetermined time after the installation. It is an object of the present invention to provide a load detector that can be easily calibrated, and a calibration device that can easily calibrate the load detector.

According to a first aspect of the invention,
A load detector for detecting a load by a subject on a bed,
A flexure element having a free end,
A support portion that supports the strain-generating body,
A mounting portion connected to the free end of the strain body and on which the bed is mounted,
A strain sensor attached to the strain generating body,
A calibration unit for calibrating the load detector,
The calibration unit, a load applying unit for applying a calibration load to the free end of the strain body,
There is provided a load detector including: an adjusting unit that adjusts the magnitude of the calibration load applied to the free end of the flexure element by the load applying unit.

  In the load detector of the first aspect, the load applying section may be fixed to the placing section and / or the strain generating element, and the adjusting section may be supported by the supporting section.

  In the load detector of the first aspect, the load applying unit is fixed to a weight and the placing unit and / or the strain-generating body, and the load by the weight is applied to the placing unit and / or the strain-generating body. The load may be transmitted to the load transmitting member, and the weight may be connected to the load transmitting member so as to be vertically movable with respect to the load transmitting member.

  In the load detector of the first aspect, the weight may be suspended from the load transmission member.

  In the load detector according to the first aspect, the load transmission member includes a first transmission member fixed to the mounting portion, a second transmission member fixed to the strain-generating body, a first transmission member, and a second transmission member. A second transmission member may be included in the second transmission member, and the weight may be suspended from the third transmission member.

  In the load detector of the first aspect, the weight may be removable.

  In the load detector of the first aspect, the adjusting unit includes a motor, an output pin that is moved around a horizontal axis by the motor, and a slide unit that is pressed by the output pin and slides in the horizontal direction. Alternatively, the slide portion may be configured to lift the weight upward when the slide portion is not pressed by the output pin.

  In the load detector of the first aspect, the load applying unit is fixed to a spring and the placing unit and / or the strain-generating body, and the load by the spring is applied to the placing unit and / or the strain-generating body. A load transmitting member that transmits the load to the load transmitting member, and the spring may be arranged to apply a load to the load transmitting member by being compressed or expanded by the adjusting portion.

According to a second aspect of the invention,
A load detector for detecting a load by a subject on a bed, wherein a strain-generating body having a free end, a support portion supporting the strain-generating body, and the bed connected to the free end of the strain-generating body are A mounting device to be mounted, and a calibration device for calibrating the load detector having a strain sensor attached to the strain-generating body,
A load applying part that is connected to the placing part and / or the flexure element and applies a calibration load to the free end of the flexure element;
There is provided a calibration device including: an adjustment unit that adjusts the magnitude of the calibration load applied to the free end of the flexure element by the load applying unit.

  In the calibration device according to the second aspect, the adjustment unit may be configured to be connected to the support unit of the load detector.

  In the calibration device according to the second aspect, the load applying unit is connected to a weight and the placing unit and / or the strain-generating body to apply a load by the weight to the placing unit and / or the strain-generating body. A load transmitting member for transmitting may be included, and the weight may be connected to the load transmitting member so as to be vertically movable with respect to the load transmitting member.

According to a third aspect of the present invention, there is provided a calibration system for calibrating a load detector of the first aspect, or a load detector to which the calibration device of the second aspect is connected,
A drive control unit for driving the load detector or the adjustment unit of the calibration device;
The detection value of the load detector when the magnitude of the calibration load applied to the free end of the strain body by the load detector or the load application unit of the calibration device is a first value, and the load application unit is Calibration of the load detector based on the detected value of the load detector when the magnitude of the calibration load applied to the free end of the strain body is a second value different from the first value A calibration system including:

According to a fourth aspect of the invention,
A load detection system for detecting a load by a subject on the bed by a plurality of load detectors, each of which is arranged under a plurality of legs of a bed, comprising a calibration device for calibrating the plurality of load detectors. There
A housing attached to the bed,
A weight movably connected to the housing,
A moving unit that moves the weight between a first position separated from the installation surface of the bed and a second position in contact with the installation surface when the housing is attached to the bed. A calibration device is provided.

  In the calibration device according to the fourth aspect, the housing may have an opening into which the weight is fitted.

According to a fifth aspect of the invention,
A calibration system for calibrating a load detector located under a leg of a bed to which the calibration device of the fourth aspect is attached,
A drive control unit for driving the moving unit of the calibration device;
The detection value of the load detector when the weight of the calibration device is at the first position separated from the installation surface of the bed, and the load detector when the weight is at the second position in contact with the installation surface of the bed And a calibration execution unit that calibrates the load detector based on the detection value of the.

  The load detector of the present invention can be easily calibrated.

  The calibration device of the present invention can easily calibrate the load detector.

FIG. 1 is a block diagram showing the configuration of a load detection system according to the first embodiment of the present invention. FIG. 2 is an explanatory diagram for explaining the arrangement of the load detector included in the load detection system with respect to the bed. FIG. 3 is a perspective view of the load detector according to the first embodiment of the present invention seen from the front. FIG. 4 is a perspective view of the load detector according to the first embodiment of the present invention seen from the rear. FIG. 5 is a partially exploded perspective view of a calibration unit included in the load detector. FIGS. 6A and 6B are explanatory views illustrating a method of switching the load applying mechanism of the calibration unit of the first embodiment between a non-load applying state and a load applying state. FIG. 6A shows the load applying mechanism in the unloaded state, and FIG. 6B shows the load applying mechanism in the loaded state. FIG. 7 is a block diagram showing the configuration of the calibration control unit. FIG. 8 is a partially exploded perspective view of a calibration unit included in the load detector of the modified example. FIG. 9A and FIG. 9B are explanatory diagrams illustrating a method of switching the load applying mechanism of the calibration unit of the modified example between the unloaded state and the unloaded state. FIG. 9A shows the load applying mechanism in the unloaded state, and FIG. 9B shows the load applying mechanism in the loaded state. FIG. 10 is a partially exploded perspective view of a calibration unit included in a load detector of another modification. FIG. 11A and FIG. 11B are explanatory diagrams illustrating a method of switching the load applying mechanism of the calibration unit according to another modification between a non-load applying state and a load applying state. FIG. 11A shows the load applying mechanism in the unloaded state, and FIG. 11B shows the load applying mechanism in the loaded state. FIG. 12 is an exploded perspective view of a modification of the calibration device. 13A and 13B are perspective views of the calibration device according to the second embodiment of the present invention. FIG. 13A shows a state where the weight is stored in the housing, and FIG. 13B shows a state where the weight is suspended from the housing.

<First Embodiment>
The load detection system 1000 (FIG. 1) of the first embodiment of the present invention will be described as an example in which the load detection system 1000 (FIG. 1) is used together with the bed BD (FIG. 2) to detect the load of the subject S on the bed BD.

[Overall configuration of load detection system]
As shown in FIG. 1, the load detection system 1000 of this embodiment mainly includes a load detection unit 100 and a control unit 300. The load detection unit 100 and the control unit 300 are connected via the A / D conversion unit 200. The storage unit 400, the display unit 500, the notification unit 600, and the input unit 700 are further connected to the control unit 300.

  The load detection unit 100 includes four load detectors 100a, 100b, 100c, 100d. The configurations of the load detectors 100a to 100d will be described later. As shown in FIG. 2, the load detectors 100a to 100d are provided below the casters Ca, Cb, Cc, Cd attached to the lower ends of the legs BLa, BLb, BLc, BLd at the four corners of the bed BD used by the subject S. Placed respectively.

  The control unit 300 is a dedicated or general-purpose computer, and mainly has a subject information calculation unit 301 and a calibration control unit (calibration system) 302 built therein. The subject information calculation unit 301 calculates, for example, the weight of the subject S, the position of the center of gravity, the locus of the center of gravity, the respiration rate, the heart rate, and the presence / absence determination based on the outputs of the load detectors 100a to 100d. The calibration control unit 302 controls the calibration of the load detectors 100a to 100d (details will be described later).

  The storage unit 400 is a storage device that stores data used in the load detection system 1000, and can be, for example, a hard disk (magnetic disk). The display unit 500 is a monitor such as a liquid crystal monitor that displays subject information such as the weight output from the control unit 300 to the user of the load detection system 1000 (for example, a medical worker, a care worker, etc.). The notification unit 600 includes a device, for example, a speaker, which auditorily performs a predetermined notification based on the output (subject information) from the control unit 300. The input unit 700 is an interface for performing a predetermined input to the load detection system 1000, and may be a keyboard and a mouse.

[Structure of load detector]
Next, the configuration of the load detectors 100a to 100d will be described. Since the load detectors 100a to 100d have the same configuration, the load detector 100a will be described here as a representative.

  As shown in FIGS. 3 and 4, the load detector 100a according to the first embodiment has first and second base portions (support portions) 11 and 12 mounted on the installation surface of the load detector 100a, and first and second The first and second beam type load cells 21 and 22 cantilevered by the second bases 11 and 12, the mounting portion 3 supported by the first and second beam type load cells 21 and 22, and the first and second beam type load cells 21 and 22. A calibration unit (calibration unit) 4 (not shown in FIG. 3) disposed between the two-beam type load cells 21 and 22 is included.

  In the following description, for the sake of convenience, the extending direction of the first and second beam type load cells 21, 22 will be referred to as the front-back direction of the load detector 100a, the side on which the mounting section 3 is located is the front side, and the calibration section 4 is located on the front side. The side to do is the rear side. The direction in which the first and second beam type load cells 21 and 22 face each other is the width direction of the load detector 100a, and the sides on which the first and second beam type load cells 21 and 22 are located are the first side and the second side, respectively. Call it the side.

  The first and second base portions 11 and 12 have long flat plate portions 11a and 12a extending in the front-rear direction, and support base portions 11b and 12b provided on the upper surfaces of the flat plate portions 11a and 12a. The support base 11b of the first base 11 is provided at the rear end of the flat plate 11a, and the support base 12b of the second base 12 is provided at the front end of the flat plate 12a. The first base portion 11 further has a flat plate-shaped calibration portion support base 11c extending in the width direction from the vicinity of the rear end of the flat plate portion 11a toward the vicinity of the front end of the flat plate portion 12a.

  The first and second beam type load cells 21 and 22 are cantilevered by the first and second base portions 11 and 12 and are arranged in parallel, and the strain elements 21s and 22s having the same shape are provided. , Strain gauges 21g and 22g attached to the flexure elements 21s and 22s.

  Each of the flexure elements 21s and 22s is a Roberval type flexure element formed of a metal such as aluminum or iron, and has a prismatic shape having a through hole (not shown) penetrating in the width direction at the center in the longitudinal direction. Is. The strain gauges 21g and 22g are attached respectively to the upper surface and the lower surface near the through holes of the flexure elements 21s and 22s, respectively. The strain gauge may be any strain sensor capable of detecting the strain generated in the flexure element.

  The lower surface near the rear end of the strain element 21s is fixed to the support base 11b of the first base portion 11, whereby the rear end is the fixed end (fixed side end) 21s1 and the front end is the free end (movable side end). Part) 21s2, which is cantilevered by the first base 11 (support base 11b). On the other hand, the lower surface of the flexure element 22s near the front end is fixed to the support base 12b of the second base 12, whereby the front end is a fixed end (fixed side end) 22s1 and the rear end is a free end ( The movable side end portion) 22s2 is cantilevered by the second base portion 12 (support base portion 12b). That is, the free end 21s2 of the flexure element 21s and the free end 22s2 of the flexure element 22s face opposite sides in the front-rear direction.

  The mounting unit 3 is a weighing pan on which a subject is mounted, and includes a plate-shaped mounting plate 31, a movable slope 32 pivotally connected to the mounting plate 31, and a mounting plate 31. It mainly includes a wall portion 33 surrounding the three sides and first and second connecting plates 341 and 342 for connecting the mounting portion 3 to the first and second beam type load cells 21 and 22.

  The movable slope 32 is a slope portion 32s that defines an inclined surface (slope) for moving a rolling element such as a caster Ca onto the mounting plate 31, and is integrally connected to the slope portion 32s. It is a plate-shaped member having a substantially U-shaped (substantially U-shaped) arm portion 32a.

  In the present embodiment, a pair of recesses (a pair of bosses (not shown) protruding from the connecting portion 31a (FIG. 4) at the front center of the mounting plate 31 to both sides in the width direction are provided at corresponding positions of the slope portion 32s ( The movable slope 32 is pivotally connected to the mounting plate 31 with the axis A (FIG. 3) as a pivot axis by being fitted in (not shown).

  Since the weight of the slope portion 32s is heavier than the weight of the arm portion 32a, the tip SLT of the slope portion 32s is in contact with the floor surface on which the load detector 100a is installed when no external force is applied ( In the state shown in FIG. 3), rolling elements such as casters Ca can easily ride on the slope portion 32s. On the other hand, after the casters Ca and the like are guided onto the mounting plate 31, the casters Ca and the like press the arm portions 32a and the recesses provided on the upper surface of the mounting plate 31 and having substantially the same shape as the arm portions 32a. 31b (state shown in FIG. 4).

  The wall portion 33 includes first and second side walls 331 and 332 that stand upright from the mounting plate 31 on both sides in the width direction of the mounting plate 31, and a rear wall 333 that stands upright from the mounting plate 31 on the rear side of the mounting plate 31. including. The front ends of the first side wall 331 and the second side wall 332 project beyond the front edge of the mounting plate 31.

  A first connecting plate 341 for connecting the mounting portion 3 to the first beam type load cell 21 is provided near the front end of the first side wall 331. The first connection plate 341 is a flat plate that projects from the outer surface of the first side wall 331 and that is parallel to the mounting plate 31. On the rear surface of the rear wall 333, a second connecting plate 342 for connecting the mounting portion 3 to the second beam type load cell 22 is provided. The second connecting plate 342 is a flat plate that projects from the rear surface of the rear wall 333 and that is parallel to the mounting plate 31.

  The mounting portion 3 fixes the upper surface of the first connecting plate 341 to the lower surface near the free end 21s2 of the flexure element 21s of the first beam type load cell 21, and the upper surface of the second connecting plate 342 to the second beam type load cell 22. By being fixed to the lower surface of the flexure element 22s near the free end 22s2, the flexure element 22s is connected to the first and second beam type load cells 21 and 22. As a result, the mounting portion 3 is supported by the first and second beam type load cells 21 and 22 so as to be vertically movable (displaceable).

  As shown in FIGS. 4 and 5, the calibration unit 4 includes a weight (weight) 41 and a load transmission unit 42 that is fixed to the mounting unit 3 and the second load cell 22 and that transmits the load of the weight 41. An adjusting mechanism (adjusting unit) that moves the applying mechanism (load applying unit) 40 and the weight 41 up and down to adjust the magnitude of the load applied to the first and second beam type load cells 21 and 22 by the load applying mechanism 40. ) 43 and mainly.

  The weight 41 may have any shape, but in the present embodiment, a part of the rectangular parallelepiped is removed (or a part of the rectangular parallelepiped is made to project like an eaves), and the pressed surface 41s that is a downward horizontal surface is provided. Have a shape. A screw hole 41h into which a suspension screw 424, which will be described later, is screwed is provided at the center of the upper surface 41t of the weight 41.

  The material of the weight 41 is arbitrary, and may be stainless steel or cast iron, for example. In the present embodiment, the weight of the weight 41 is set so that the weight of the weight 41 and the suspension screw 424 described later will total 100 grams. As a result, a load equivalent to the load applied when the weight of the subject on the mounting table 3 changes by 100 grams can be applied to the first and second beam type load cells 21, 22 by the load applying mechanism 40. .

  The weight of the weight 41 (or the total weight of the weight 41 and the suspension screw 424) is arbitrary, but the minimum display of the load detector 100a including the calibration unit 4 (the load change amount readable by the load detector is By taking into consideration the minimum unit) and setting the weight such that the magnitude of the load applied by the load applying mechanism 40 matches the minimum display, the weight 41 can be made light and small while maintaining the accuracy of calibration. . Further, it is desirable that the weight of the weight 41 (or the total weight of the weight 41 and the suspension screw 424) be calibrated.

  The load transmitting portion 42 includes a placing portion side transmitting member (first transmitting member) 421 fixed to the placing portion 3 and a load cell side transmitting member (first transmitting member) 421 fixed to the strain generating element 22s of the second beam type load cell 22. 2 transmission member) 422, a central transmission member (third transmission member) 423 provided across the mounting portion side transmission member 421 and the load cell side transmission member 422, and a through hole 423h included in the central transmission member 423. And a suspension screw (suspension member) 424 screwed into the screw hole 41h of the weight 41.

  The mounting portion side transmission member 421 is a member having an L-shaped cross section (angled shape) screwed to the rear surface of the rear wall 333 of the mounting portion 3. The upper surface 421t of the mounting portion side transmission member 421 is a horizontal surface extending in the width direction along the rear wall 333.

  The load cell-side transmission member 422 is a member in which a long flat plate is curved twice in the width direction to have a substantially S-shaped cross section, and one side with the curved portion interposed therebetween has a free end 22s2 of the flexure element 22s of the second load cell 22. It is screwed to the upper surface in the vicinity. The other side of the curved portion is slightly spaced from the mounting portion 3 and is positioned behind the mounting portion 3, and the upper surface 422t thereof is a horizontal plane extending in the width direction along the rear wall 333.

  The upper surface 421t of the mounting portion side transmission member 421 and the upper surface 422t of the load cell side transmission member 422 are flush with each other. Further, the end portion of the mounting portion side transmission member 421 on the second beam type load cell 22 side (second side) and the end portion of the load cell side transmission member 422 on the first beam type load cell 21 side (first side) are , Are separated from each other in the width direction by a predetermined distance.

  The center transmission member 423 is a long flat plate, and has a through hole 423h at a substantially central portion in the longitudinal direction. The central transmission member 423 is laid between the mounting portion side transmission member 421 and the load cell side transmission member 422 so that the through hole 423h is positioned in the gap between them, and the first side end portion is mounted. The end portion on the second side is screwed to the upper surface 421t of the placing portion side transmission member 421 and the upper surface 422t of the load cell side transmission member 422, respectively.

  The suspension screw 424 is a stepped screw having a head portion 424h, a large diameter cylindrical portion 424c, and a small diameter screw portion 424s, and is inserted into the through hole 423h of the central transmission member 423 from above as shown in FIG. The screw portion 424s is screwed into the screw hole 41h of the weight 41. Accordingly, the weight 41 is suspended from the central transmission member 423 by the suspension screw 424 so as to be vertically movable.

  Since the diameter of the head portion 424h is larger than the diameter of the through hole 423h, the suspension screw 424 moves below the descending position (FIG. 6B) where the head portion 424h abuts the upper surface 423t of the central transmission member 423. There is nothing to do. Further, since the outer diameter of the cylindrical portion 424c is slightly smaller than the inner diameter of the through hole 423h, the suspension screw 424 and the weight 41 are guided by the through hole 423h and stably move in the vertical direction. The suspension screw 424 is not limited to a stepped screw, and may be any member such as a pin that can suspend the weight 41 so as to be vertically movable.

  The adjustment mechanism 43 includes a plate-shaped base 431 fixed to the calibration unit support base 11c of the first support 11, a motor 432 fixed to the plate-shaped base 431, and a gear train that transmits the output of the motor 432 to the output pin PN. 433 and. The motor 432 is connected to the control unit 300 by wiring (not shown).

  The gear train 433 includes a worm gear W fixed to the output shaft of the motor 432, a small-diameter first gear G1, a second gear G2 that is a two-stage gear, and a large-diameter first gear with the output pin PN fixed to the side surface. And three gears G3. The rotation axes of the first, second, and third gears G1, G2, G3 coincide with the front-back direction of the load detector 100a. The output pin PN has a cylindrical shape as an example, and is arranged such that the outer peripheral surface thereof overlaps with the pressed surface 41 s of the weight 41 in a plan view.

  The output of the motor 432 is transmitted in the order of the worm gear W, the first gear G1, the large diameter gear of the second gear G2, the small diameter gear of the second gear G2, and the third gear G3. When the motor 432 rotates, the third gear G3 rotates, and the output pin PN moves on the circumference around the rotation axis x (FIGS. 6A and 6B) of the third gear G3. In response to this movement (up and down movement), the output pin PN comes into contact with or separates from the pressed surface 41s of the weight 41.

  As shown in FIG. 6A, when the output pin PN is directly above the rotation axis x of the third gear G3, the output pin PN comes into contact with the pressed surface 41s of the weight 41 from below and 41 is being lifted. In this state, since the head portion 424h of the suspension screw 424 connected to the weight 41 is separated from the upper surface 423t of the central transmission member 423, the load of the weight 41 is applied to the central transmission member 423, and thus the first and second portions. Without being transmitted to the beam type load cells 21 and 22, it is transmitted to the calibration section support base 11c mounted on the installation surface of the load detector 100a via the output pin PN, the third gear G3, and the plate-shaped base portion 431. To be done.

  The state in which the weight 41 is lifted by being pressed from below by the output pin PN is called a weight lifted state. In addition, a state in which the load of the weight 41 (calibration load) to the first and second beam type load cells 21 and 22 is interrupted by the weight 41 being in the weight rising state is referred to as a no load applied state. Call. The weight rising state and the unloaded state are not limited to the case where the output pin PN is located right above the rotation axis x of the third gear G3, but the output pin PN has the head 424h of the suspension screw 424 and the central holding member 423. Occurs when the weight 41 is lifted to a distance from the upper surface 423t.

  As shown in FIG. 6B, when the output pin PN is at substantially the same height as the rotation axis x of the third gear G3, the output pin PN is separated from the pressed surface 41s of the weight 41. In this state, the head 424h of the suspension screw 424 connected to the weight 41 abuts against and is supported by the upper surface 423t of the central transmission member 423, so that the weight (calibration load) of the weight 41 is suspended. It is transmitted (given) to the free end 21s2 of the first beam type load cell 21 via the screw 424, the central transmission member 423, the mounting portion side transmission member 421, and the mounting portion 3, and the suspension screw 424, the central transmission member 423, and the load cell. It is transmitted (applied) to the free end 22s2 of the second beam type load cell 22 via the side transmission member 422.

  In this way, the state in which the output pin PN is separated from the pressed surface 41s and the weight 41 is lowered is referred to as a weight lowered state. In addition, a state in which the weight of the weight 41 is applied to the first and second beam type load cells 21 and 22 via the load transmission portion 42 when the weight 41 is in the weight descending state is referred to as a load application state. The load applying mechanism 40 of the present embodiment is not limited to the case where the output pin PN is located at substantially the same height as the rotation axis x of the third gear G3, but the weight is provided when the output pin PN is separated from the pressed surface 41s. The descent state and the load application state are set.

  Note that changing the load applying mechanism 40 between the load applying state and the non-load applying state by using the adjusting mechanism 43 means that the “adjusting section” of the present invention is “the load applying section is at the free end of the flexure element”. The adjustment of the magnitude of the calibration load to be applied ”is one mode.

  Next, a method of detecting the load of the subject S and calibrating the load detectors 100a to 100d using the load detection system 1000 of the present embodiment will be described. It is assumed that the zero points of the load detectors are adjusted with the bed BD placed on the load detectors 100a to 100d.

  The load detection of the subject S is performed by processing the detection values (load values) of the load detectors 100a to 100d in the subject information calculation unit 301 of the control unit 300. Specifically, for example, the weight of the subject S can be obtained by adding the detection values of the load detectors 100a to 100d.

  After the load detectors 100a to 100d are installed under the legs BLa to BLd of the bed BD, an error may occur in the detection values of the load detectors 100a to 100d after a lapse of time. The error in the detected value is due to, for example, deformation of the strain generating bodies 21s and 22s, displacement of the mounting positions of the strain gauges 21g and 22g with respect to the strain generating bodies 21s and 22s, and the like. Therefore, it is desirable to periodically calibrate the load detectors 100a to 100d.

  Since the methods for calibrating the load detectors 100a to 100d are the same, the method for calibrating the load detector 100a will be described here as a representative.

  The calibration of the load detector 100a is performed using the calibration unit 4 included in the load detector 100a and the calibration control unit 302 built in the control unit 300.

  As shown in FIG. 7, the calibration control unit (calibration system) 302 includes a drive control unit 3021 that controls driving of the adjustment mechanism 43 of the calibration unit 4, and a calibration execution unit that performs calibration based on the output value of the load detector. 3022.

  In the calibration of the load detector 100a, first, the calibration execution unit 3022 outputs the output value of the load detector 100a when the load application mechanism 40 of the calibration unit 4 is in the no load application state (hereinafter, "when no load application is performed"). (Called “output value”). Next, the drive control unit 3021 drives the adjustment mechanism 43 of the calibration unit 4 to displace the load applying mechanism 40 to the load applying state, and the calibration executing unit 3022 detects the load when the load applying mechanism 40 is in the load applying state. The output value of the container 100a (hereinafter, appropriately referred to as "load applied output value") is stored.

  After that, the calibration execution unit 3022, based on the stored output value without load and output value with load, and various values indicating the characteristics of the load detector 100a stored in the storage unit 400 in advance, the load detector 100a. It is determined whether or not there is an error in the output value of.

  When the calibration execution unit 302 determines that an error has occurred in the output value of the load detector 100a, it sends an instruction to the subject information calculation unit 301 to instruct the output value of the load detector 100a to perform the necessary compensation. To send. Alternatively, if physical repair or the like of the load detector 100a is required, the fact is displayed to the user via the display unit 500.

  Such load detectors 100a to 100d can be calibrated while the subject S is present on the bed BD. In this case, for example, it is determined whether or not the zero point is changed based on the output values when no load is applied, the output values when a load is applied, and the various characteristic values of the load detectors 100a to 100d, and if necessary, it is determined. This can be compensated. When the calibration is performed in the state where the subject S does not exist on the bed BD, the presence or absence of the change of the zero point can be confirmed only by confirming the output value when no load is applied. In this case, for example, the increase amount of the output value at the time of load application with respect to the output value at the time of no load application is an amount according to the magnitude of the calibration load applied by the load application mechanism 40 (for example, stored as a known reference value). Whether or not there is an error can be determined based on whether or not there is an error (stored in the unit 400). In addition, the calibration can be performed in various modes by using the calibration unit 4 that can apply the calibration load having a known size at a desired timing. The calibration may be performed with the load detector removed from under the bed BD.

  The effects of the load detector 100a included in the load detection system 1000 of this embodiment are summarized below.

  Since the load detector 100a of the present embodiment includes the calibration unit 4 that can apply a calibration load to the first and second beam type load cells 21 and 22, the load detector 100a is installed under the bed BD. The calibration can be easily performed in the state of being kept.

  More specifically, since the calibration unit 4 can automatically add the calibration load, the operator does not have to go under the bed BD to calibrate the load detector 100a. Therefore, the calibration work is efficient and highly safe. Furthermore, by remotely controlling the calibration unit 4, it is possible to perform calibration without going to the installation location of the load detector 100a.

  Further, for example, even when a serious patient who cannot move from the bed is lying on the bed, the calibration can be performed without affecting the patient.

  Since the calibration unit 4 included in the load detector 100a of the present embodiment applies the calibration load based on the weight of the weight 41 that can be calibrated by itself, the calibration can be performed accurately.

  In the load detector 100a of the present embodiment, the calibration unit 4 is disposed between the first and second beam type load cells 21 and 22 behind the mounting unit 3, so that the load detector 100a is compact. is there. Moreover, since the adjusting mechanism 43 has a simple structure including the motor 431 and the gear train 432, the adjusting mechanism 43 can be manufactured easily and at low cost.

  The load detection system 1000 of the present embodiment also includes the load detectors 100a to 100d, and therefore has the same effect. In particular, if the calibration control unit 302 is set to periodically calibrate the load detectors 100a to 100d using the calibration unit 4, the error in the detection value of the load detector can be automatically compensated periodically. The reliability of the detected value can be easily maintained for a long period of time.

<First Modification>
Next, a first modified example of the load detectors 100a to 100d will be described with reference to FIGS. 8, 9A, and 9B.

  The main difference between the load detector 101 of the first modified example and the load detectors 100a to 100d is that the weight 41 of the calibration unit 4 further has a ridge-shaped convex portion 41p provided in the lower surface thereof and extending in the front-rear direction. The point is that the adjusting mechanism 43 of the calibration unit 4 further includes a slide unit 434 that is pushed by the output pin PN and moves in the width direction.

  The slide portion 434 includes a slide piece SL slidably attached to the calibration portion support base 11c, a spring fixing wall WL that stands upright from the calibration portion support base 11c on the first side of the slide piece SL, a slide piece SL and a wall portion. A spring SP disposed between the spring and the WL.

  The slide piece SL includes an elongated flat plate-shaped base portion SL1, a pressed wall SL2 standing upright from one end of the base portion SL1, a spring fixing wall SL3 standing up from the other end of the base portion SL1, and a pressing portion projecting rearward from a side surface of the base portion SL1. And a piece SL4.

  The spring SP is a coil spring in this embodiment. One end of the spring SP is fixed to the spring fixing wall WL, and the other end is fixed to the spring fixing wall SL3 of the slide piece SL.

  In the load detector 101 of the first modified example, the calibration unit support base 11c of the first support unit 11 has a smaller width in the front-rear direction than the calibration unit support base 11c of the first embodiment. The base portion SL1 of the slide piece SL is attached to the calibration portion support base 11c via, for example, slits and pins (not shown) so that the pressing piece SL4 moves in the width direction behind the calibration portion support base 11c. The pressing piece SL4 overlaps with the weight 41 in a plan view, and when the spring SP has a free length, the pressing piece SL4 is provided directly below the convex portion 41p of the weight 41.

  In the calibration unit 4 of the modified example, the load applying mechanism 40 is switched between the weight rising state (no load applied state, FIG. 9A) and the weight lowered state (load applied state, FIG. 9B) as follows. Is done like.

  As shown in FIG. 9A, when the output pin PN is directly below the rotation axis x of the third gear G3, the output pin PN is separated from the pressed wall SL2 of the slide piece SL, and the slide piece SL. Is pulled to the first side by the spring SP. At this time, the spring SP has a free length, and the pressing piece SL4 of the slide piece SL lifts the weight 41 via the convex portion 41p of the weight 41. In this state, since the head portion 424h of the suspension screw 424 connected to the weight 41 is separated from the upper surface 423t of the central transmission member 423, the load of the weight 41 is applied to the first and second beam type load cells 21 and 22. It is transmitted to the calibration unit support base 11c via the slide piece SL without being transmitted. Such a weight rising state and no load applying state of the load applying mechanism 40 are not limited to the case where the output pin PN is located directly below the rotation axis x of the third gear G3, and the output pin PN is not covered by the slide piece SL. It occurs if it is separated from the pressing wall SL2.

  As shown in FIG. 9B, when the output pin PN is at a position on a horizontal line extending from the rotation axis x of the third gear G3 to the second side, the output pin PN does not contact the pressed wall SL2 of the slide piece SL. It is pressed to the second side, whereby the slide piece SL is shifted to the second side and the spring SP is expanded. At this time, the pressing piece SL4 of the slide piece SL is shifted to the second side from directly below the convex portion 41p of the weight 41, and the weight 41 is not lifted via the convex portion 41p. In this state, the head 424h of the suspension screw 424 connected to the weight 41 abuts against and is supported by the upper surface 423t of the central transmission member 423, so that the load of the weight 41 passes through the load transmission portion 42. And transmitted to the first and second beam type load cells 21 and 22. The weight descending state and the load applying state of the load applying mechanism 40 are slid to the extent that the output pin PN presses the pressed wall SL2 and the lifting of the weight 41 by the pressing piece SL4 via the convex portion 41p is released. It occurs if one piece SL is moved.

  According to the load detector 102 of the first modified example, in addition to the effect of the load detector 100a of the first embodiment, the following effect is further exhibited. That is, the load applying mechanism 40 of the calibration unit 4 included in the load detector 102 is in a no load applied state in a state where the output pin PN does not press the pressed portion SL2 of the slide piece SL, and therefore during normal load detection. No load is applied to the output pin PN and the gear train 432. Therefore, the mechanical fatigue of the calibration unit 4 is small. By adjusting the position of the convex portion 41p of the weight 41p and / or the position of the pressing piece SL4 of the slide piece SL, no load is applied when the output pin PN is pressing the pressed portion SL2 of the slide piece SL. It can also be configured to be in a state.

  In the first embodiment and the first modification, the weight 41 may be removable from the load applying mechanism 40. The accuracy of calibration can be improved by replacing the weight 41 with a different weight according to the characteristics of the load cell including the calibration unit 4. Further, when the weight 41 itself needs to be calibrated, this can be easily performed.

  In the first embodiment and the first modification, the suspension of the weight 41 is not limited to the mode in which the suspension screw 424 and the through hole 423h are used. For example, a linear member such as a string is used to suspend the weight 41 from the central holding member 423. May be. Alternatively, the weight 41 is arranged on the upper surface of the central transmission member 423 so as to be vertically movable between a weight descending position in contact with the central transmission member 423 and a weight rising position separated from the central transmission member 423, and a through hole 423h is provided. The cylindrical pressing member may be moved up and down by the adjusting mechanism 43 to switch between the two positions.

<Second Modification>
Next, a second modified example of the load detectors 100a to 100d will be described with reference to FIGS. 10, 11A, and 11B.

  The main difference between the load detector 102 of the second modification and the load detectors 100a to 100d is that the calibration unit 4 includes a pressing member 44 instead of the weight 41, and the pressing member 44 and the central transmission member 423 are different from each other. The point is that a spring 45 arranged between them is provided.

  The pressing member 44 has substantially the same shape as the weight 41. That is, it has a shape in which a part of the rectangular parallelepiped is removed to provide a pressed surface 44s which is a downward horizontal surface. A screw hole 44h into which the suspension screw 424 is screwed is provided at the center of the upper surface 44t of the pressing member 44. The pressing member 44 is not a member that functions as a weight, but a member that compresses the spring 45 according to the movement of the output pin PN.

  As shown in FIG. 10, the suspension screw 424 is inserted from above into the through hole 423h of the central transmission member 423, and is screwed into the screw hole 44h of the pressing member 44 via the spring 45 (compression coil spring as an example). . The spring 45 is located around the cylindrical portion 424c of the suspension screw 424, and its upper end is in contact with the lower surface 423u of the central transmission member 423 and its lower end is in contact with the upper surface 44t of the pressing member 44.

  In the calibration unit 4 of the modified example, switching between the load applying state and the load non-applying state of the load applying mechanism 40 is performed as follows.

  As shown in FIG. 11A, when the output pin PN is separated from the pressed surface 44 s of the pressing member 44, the spring 45 has a free length and the suspension screw 424 connected to the pressing member 44. The head 424h of the central contact member 424h abuts against and is supported by the upper surface 423t of the central transmission member 423. At this time, since the pressing member 44 is lightweight or the load by the pressing member 44 is removed by zero adjustment of the load detector 102, the first and second beam type load cells 21, 22 by the load applying mechanism 40 are moved. The load is not substantially applied. As described above, the state in which the spring 45 has a free length and does not press the lower surface 423u of the central transmission member 423 does not apply a load in the load applying mechanism 40 of the calibration unit 4 included in the load detector 102 of the second modified example. It is in a state.

  As shown in FIG. 11B, when the output pin PN contacts the pressed surface 44 s of the pressing member 44 from the lower side and lifts the pressing member 44, the spring 45 moves the lower surface of the central transmission member 423. 423u and the upper surface 44t of the pressing member 44 are sandwiched and compressed, and the central transmission member 423 is pressed upward by the reaction force. This pressing force (upward force) is transmitted to the first and second beam type load cells 21, 22 via the load transmitting portion 42. In this way, the spring 45 is compressed, and the state in which the reaction force of the spring 45 is transmitted to the first and second beam type load cells 21 and 22 via the load transmission portion 42 is the calibration portion 4 of the second modified example. The load applying mechanism 40 applies the load. The load is applied upward to the second beam type load cell 22 unlike the calibration unit 4 of the first embodiment and the first modification, but if it is considered that a predetermined negative load is applied, It does not make a substantial difference in the calibration. Since the compression amount of the spring 45 varies depending on the vertical position of the output pin PN, the magnitude of the load applied varies depending on the vertical position of the output pin.

  As described above, according to the load detector 102 of the second modified example, in addition to the effect of the load detector 100a of the first embodiment, the magnitude of the load applied to the first and second beam load cells 21 and 22 is further increased. There is an effect that the height can be adjusted.

  By connecting the spring 45 to the pressing member 44 and connecting the pressing member 44 to the output pin PN, the pressing member 44 is pulled down by the output pin PN moving downward to extend the spring 45. A downward load may be applied to the two-beam type load cells 21 and 22.

  In the second modification, the spring 45 may be removable from the load applying mechanism 40. The accuracy of calibration can be improved by replacing the spring 45 with a spring having a different spring constant as needed. It is advantageous that the size of the load that can be applied by the load applying mechanism 40 can be changed without increasing the size and weight of the calibration unit 4 simply by replacing the spring 45 with a different spring constant.

  In the first embodiment and each modified example, the load transmission part 42 has three members, that is, the mounting part side transmission member 421, the load cell side transmission member 422, and the central transmission member 423, but the present invention is not limited to this. . For example, the mounting portion side transmission member 421 and the central transmission member 423 are omitted, and a through hole is provided at an end portion of the load cell side transmission member 422 opposite to the end portion fixed to the second beam type load cell 22. The weight 41 may be suspended by a suspension screw 424 that passes through the through hole.

  In the first embodiment and each modified example, the load transmission part 42 is fixed to the second beam type load cell 22, but the present invention is not limited to this, and the load transmission part 42 may be fixed to the mounting part 3. Good. Specifically, for example, the mounting portion side transmission member 421 and the load cell side transmission member 422 may be omitted, and the central transmission member 423 may be directly fixed to the rear surface of the rear wall 333 of the mounting portion 3. In this case, the load of the weight 41 is transmitted to the free ends of the first and second beam type load cells 21, 22 via the central transmission member 423 and the mounting portion 3.

  In the first embodiment and each modified example, the load applying mechanism 40 of the calibration unit 4 may not have the load transmission unit 42. In this case, for example, the weight 41 is suspended from the free end 22s2 of the flexure element 22s of the second beam type load cell 22, or the spring 45 is arranged below the free end 22s2. The adjusting mechanism 43 extends the flat plate portion 12a of the second base portion 12 to a position below the free end 22s2 and arranges the flat plate portion 12a near the tip thereof.

  In the first embodiment and each modified example, the adjustment mechanism 43 is not limited to a mechanism having a motor and a gear train, and the load imparting mechanism 40 applies a calibration load to the first and second beam type load cells 21 and 22. An arbitrary mechanism whose size can be adjusted can be used. Specifically, for example, a piezoelectric actuator can be used instead of the motor, and a ball screw mechanism or a belt mechanism can be used instead of the gear train. The configuration used can be adopted. As an example, an output unit that is vertically moved by a piezoelectric actuator may be provided below the weight 41 and the spring 45, and the output unit may lift the weight 41 or compress the spring 45.

  The calibration unit 4 of the first embodiment and the modification may have a structure without the weight 41, the spring 45, and the load transmission unit 42. Specifically, for example, the flat plate portion 12a of the second base portion 12 is extended below the free end 22s2 of the flexure element 22s of the second beam load cell 22, and is vertically moved by a piezoelectric actuator to the upper surface near the tip thereof. The pressing member is placed. The load is applied to the free end 22s2 of the flexure element 22s by raising the pressing member by the piezoelectric actuator and pressing the free end 22s2 upward. In this case, the pressing member corresponds to the “load applying section” of the present invention, and the piezoelectric actuator corresponds to the “adjusting section” of the present invention.

  The calibration unit of the first embodiment and each modification may be a calibration device that is independent of the load detector and is attachable to and detachable from the load detector.

  As shown in FIG. 12, the calibration device 5 includes a load applying mechanism (load applying part) 40 and an adjusting mechanism (adjusting part) 43, and the load applying mechanism 40 includes a weight (weight) 41, as shown in FIG. A load transmission plate (load transmission portion) 46 that transmits the load of the weight 41 and a suspension screw 424 that suspends the weight 41 from the load transmission plate 46 are included. The structures of the weight 41, the adjustment mechanism 43, and the suspension screw 424 are as described in relation to the calibration unit 4 of the first embodiment.

  The load transmission plate 46 is a long flat plate, and a through hole 46h through which the suspension screw 424 is inserted is provided near one end thereof. The adjustment mechanism 43 and the load transmission plate 46 may be connected by a linear member or a link mechanism that does not affect the movement of the load transmission plate 46.

  When the calibration device 5 is used for, for example, the load detector 103 having no calibration unit, first, the load transmission plate 46 is provided on the upper surface of the load detector 103 in the vicinity of the free end 22s2 of the second beam type load cell 22. The end opposite to the end provided with the through hole 46h is fixed, and the adjustment mechanism 43 is fixed to the upper surface of the calibration unit support 11c. This fixing can be performed using a magnet, a bolt, or the like. Next, the weight 41 is suspended and supported via the suspension screw 424 and the through hole 46h so that the output pin PN of the adjustment mechanism 43 and the pressed surface 41s of the weight 41 overlap in a plan view.

  In FIG. 12, the adjusting mechanism 43 is arranged on the calibration unit support base 11c of the load detector 103, but if the load detector to be used does not have such a support base, the load is The adjustment mechanism 43 is appropriately arranged so as to be supported on the fixed end side of the strain generating element of the detector. Alternatively, the adjusting mechanism 43 may be placed directly on the installation surface on which the load detector 103 is installed, without attaching the adjustment mechanism 43 to the load detector 103.

  The operation and usage of the calibration device 5 attached to the load detector are substantially the same as the operation and usage of the calibration unit 4 of the first embodiment. In the load applied state, the load of the weight 41 is transmitted to the second beam type load cell 22 via the suspension screw 424 and the load transmission plate 46. The adjustment mechanism 43 may be provided with a battery and a wireless transmission / reception unit, or may be provided with a connector for connecting wiring for power supply and communication.

<Second Embodiment>
Next, a calibration device according to a second embodiment of the present invention will be described with reference to FIGS. 13 (a) and 13 (b).

  The calibration device 6 according to the second embodiment includes a casing 61, a weight 62 that is attachable to and detachable from the casing 61, a weight moving unit (moving unit) 63 housed inside the casing 61, a battery 64, and It mainly has a pulley PU.

  The housing 61 is a rectangular parallelepiped box whose one surface is open, and the weight 62 is configured to be fittable into the opening 61 a of the housing 61 like a lid. On the outer surface of the bottom portion 61b of the housing 61, a mounting portion (not shown; a magnet as an example) for mounting the calibration device 6 on the bed BD is provided. A slit 61c for passing a linear member L (described later) that connects the housing 61 and the weight 62 is provided on the side surface of the housing 61.

  The weight 62 is a weight for applying a calibration load to the load detector, similar to the weight 41 of the first embodiment. The weight is arbitrary, and the optimum weight may differ depending on the load detector to be calibrated, but is 400 grams in the present embodiment.

  The housing 61 and the weight 62 are connected via a pulley PU rotatably provided on the housing 61 and a linear member L having one end connected to the pulley PU and the other end connected to the weight 62. .

  The weight moving unit 63 includes a plate-shaped base 631 fixed to the inner surface of the bottom 61b of the housing 61, a motor 632 fixed to the plate-shaped base 631, and a gear train 633 that transmits the output of the motor 632 to the pulley PU. Including. The motor 632 is connected to the battery 64 by wiring (not shown).

  The gear train 633 includes a worm gear W1 fixed to the output shaft of the motor 632, a small-diameter first gear G1, a second gear G2 that is a two-stage gear, a large-diameter third gear G3, and a pulley PU coaxial with each other. And a worm gear W2 connected in a line.

  The output of the motor 632 is transmitted in the order of the worm gear W1, the first gear G1, the large diameter gear of the second gear G2, the small diameter gear of the second gear G2, the third gear G3, and the worm gear W2. When the motor 632 rotates, the worm gear W2 rotates and the pulley PU rotates. The rotation of the pulley PU causes the linear member L to be wound around the pulley PU and the linear member L to be fed out from the pulley PU.

  In the calibration device 6 of the second embodiment, specifically, in the load detection system 1000 of the first embodiment, for example, the load detectors 100a to 100d are load detectors 104a to 104d (FIG. 2) and the like can be used.

  Also in such a load detection system, the load detectors 104a to 104d are respectively installed under the casters Ca to Cd at the lower ends of the legs BLa to BLd at the four corners of the bed BD, as shown in FIG. .

  When calibrating the load detectors 104a to 104d, first, the housing 61 of the calibration device 6 is attached to the bed BD at the position O (FIG. 2) equidistant from the load detectors 104a to 104d. Then, the linear member L is sufficiently fed from the pulley PU until the weight 62 suspended from the housing 61 through the slit 61c comes into contact with the floor surface on which the bed BD is installed.

  When the weight 62 is in contact with the installation surface of the bed BD, the load of the weight 62 is directly transmitted to the floor surface without being transmitted to the load detectors 104a to 104d. Therefore, this state corresponds to the unloaded state in the calibration unit 4 of the first embodiment.

  Next, the motor 632 of the calibration device 61 is driven to wind the linear member L around the pulley PU. When the weight 62 is separated from the floor surface, the load of the weight 62 is transmitted to the bed BD via the linear member L, the pulley PU, the weight moving portion 63, and the housing 61, and is transmitted to the load detectors 104a to 104d. Since the calibration device 61 is attached to the bed BD at a position O equidistant from each of the load detectors 104a to 104d, the load of the weight 62 is evenly divided and transmitted to each of the load detectors 104a to 104d. It This state corresponds to the load application state in the calibration unit 4 of the first embodiment.

  In this way, the load detectors 104a to 104d are calibrated in the same manner as in the first embodiment by switching between the load application state and the load non-application state by the calibration device 61 attached to the bed BD. You can

  The housing 61 may be provided with a wireless transmission / reception unit, and the calibration control unit 302 may control the drive of the weight moving unit 63 wirelessly. Alternatively, the housing 61 may be provided with a connector for connecting the wiring connecting the calibration control unit 302 and the calibration device 6.

  According to the calibration device 6 of the second embodiment, the calibration of the plurality of load detectors included in the load detection system 1000 is installed under the bed BD only by mounting the calibration device 6 at an appropriate position on the bed BD. As it is, it can be easily performed. In addition, when the calibration device 6 of the second embodiment is used, a plurality of load detectors are not provided with calibration units to provide a load for calibration to each load detector, but a plurality of load detectors are used to perform plural calibrations. It is possible to apply the calibration load to all the load detectors. Since this simplifies the mechanism for applying the calibration load to the plurality of load detectors, (1) the cost required for calibrating the plurality of load detectors is reduced, and (2) the calibration load is applied. The probability of failure occurring in the mechanism is reduced. (If the failure occurrence probability of each device is the same, the number of devices is 1/4 compared to the case where a calibration unit is provided for each load detector. The probability of occurrence is also 1/4). Further, since the calibration device 6 has less dimensional restrictions than a device built in or attached to the load detector, it can be manufactured with a size advantageous in terms of cost and can be made cheaper.

  The description of the above-described embodiments and modifications is made by way of example for a load detector having a pair of beam type load cells, but the calibration unit and the calibration device of the present invention can be applied to any load detector. It can be used for. Specifically, for example, a single load cell type load detector in which a weighing pan is connected to an end of a single beam type load cell as disclosed in Japanese Patent No. 5143946, and Japanese Patent Laid-Open No. 2005-300368 are disclosed. A load scale having three load cell sensors as disclosed in Japanese Patent Application No. 2008-095133, which has not been published by the present applicant at the time of filing of the present application, can also be used.

  As long as the features of the present invention are maintained, the present invention is not limited to the above-described embodiments, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. .

  According to the load detector and the calibration device of one embodiment of the present invention, the load detector can be easily calibrated at a medical site, a nursing site, etc., and it can contribute to the improvement of quality of medical care and care.

11 1st base part, 12 2nd base part, 21 1st beam type load cell, 22 2nd beam type load cell, 3 mounting part, 4 calibration part, 40, load provision mechanism, 41 weight, 42 load transmission part, 43 adjustment mechanism , 44 pressing member, 45 spring, 46, load transmission plate, 5, 6 calibration device, 61 housing, 62 weight, 63 moving part, 64 battery, 100 load detecting part, 100a, 100b, 100c, 100d load detector, 200 A / D conversion unit, 300 control unit, 301 subject information calculation unit, 302 calibration control unit, 400 storage unit, 500 display unit, 600 notification unit, 700 input unit, 1000 load detection system, BD bed, S subject

Claims (15)

A load detector for detecting a load by a subject on a bed,
A flexure element having a free end,
A support portion that supports the strain-generating body,
A mounting portion connected to the free end of the strain body and on which the bed is mounted,
A strain sensor attached to the strain generating body,
A calibration unit for calibrating the load detector,
The calibration unit, a load applying unit for applying a calibration load to the free end of the strain body,
A load detector comprising: an adjusting unit that adjusts the magnitude of the calibration load applied to the free end of the flexure element by the load applying unit.   The load detector according to claim 1, wherein the load applying section is fixed to the placing section and / or the strain generating element, and the adjusting section is supported by the supporting section.   The load applying section includes a weight and a load transmitting member that is fixed to the placing section and / or the strain-generating body and that transmits a load by the weight to the placing section and / or the strain-generating body. The load detector according to claim 2, wherein the weight is connected to the load transmitting member so as to be vertically movable with respect to the load transmitting member.   The load detector according to claim 3, wherein the weight is suspended from the load transmission member.   The load transmission member includes a first transmission member fixed to the mounting portion, a second transmission member fixed to the strain-generating body, and a third transmission member bridged between the first transmission member and the second transmission member. The load detector according to claim 4, further comprising a transmission member, wherein the weight is suspended from the third transmission member.   The load detector according to claim 3, wherein the weight is removable.   The adjustment unit includes a motor, an output pin that is moved around a horizontal axis by the motor, and a slide unit that is pressed by the output pin and slides in the horizontal direction. The slide unit is pressed by the output pin. The load detector according to any one of claims 3 to 6, which is configured to lift the weight upward in a state in which the load is not lifted.   The load applying unit includes a spring and a load transmitting member that is fixed to the placing unit and / or the strain-generating body and that transmits a load by the spring to the placing unit and / or the strain-generating body. The load detector according to claim 2, wherein the spring is arranged so as to apply a load to the load transmitting member by being compressed or expanded by the adjusting portion. A load detector for detecting a load by a subject on a bed, wherein a strain-generating body having a free end, a support portion supporting the strain-generating body, and the bed connected to the free end of the strain-generating body are A mounting device to be mounted, and a calibration device for calibrating the load detector having a strain sensor attached to the strain-generating body,
A load applying part that is connected to the placing part and / or the flexure element and applies a calibration load to the free end of the flexure element;
A calibration device, comprising: an adjustment unit that adjusts the magnitude of the calibration load applied to the free end of the strain body by the load application unit.   The calibration device according to claim 9, wherein the adjustment unit is configured to be connected to the support unit of the load detector.   The load applying unit includes a weight and a load transmitting member that is connected to the placing unit and / or the strain-generating body and transmits a load by the weight to the placing unit and / or the strain-generating body. The calibration device according to claim 10, wherein the weight is connected to the load transmitting member so as to be vertically movable with respect to the load transmitting member. A calibration system for calibrating a load detector according to any one of claims 1 to 8 or a load detector to which the calibration device according to any one of claims 9 to 11 is connected. hand,
A drive control unit for driving the load detector or the adjustment unit of the calibration device;
The detection value of the load detector when the magnitude of the calibration load applied to the free end of the strain body by the load detector or the load application unit of the calibration device is a first value, and the load application unit is Calibration of the load detector based on the detected value of the load detector when the magnitude of the calibration load applied to the free end of the strain body is a second value different from the first value A calibration system comprising: A load detection system for detecting a load by a subject on the bed by a plurality of load detectors, each of which is arranged under a plurality of legs of a bed, comprising a calibration device for calibrating the plurality of load detectors. There
A housing attached to the bed,
A weight movably connected to the housing,
A moving unit that moves the weight between a first position separated from the installation surface of the bed and a second position in contact with the installation surface when the housing is attached to the bed. Calibration device.   The calibration device according to claim 13, wherein the housing has an opening into which the weight is fitted. A calibration system for calibrating a load detector arranged under a leg of a bed to which the calibration device according to claim 13 or 14 is attached,
A drive control unit for driving the moving unit of the calibration device;
The detection value of the load detector when the weight of the calibration device is at the first position separated from the installation surface of the bed, and the load detector when the weight is at the second position in contact with the installation surface of the bed And a calibration execution unit that calibrates the load detector based on the detection value of.

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