JP2011191088A - Load meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a load meter capable of precisely measuring a load value, in a load meter receiving the effects of biased placement. <P>SOLUTION: The load meter stores, in advance, calibration tables A361, B362 that stipulate a calibration value for a detection value of a load sensor for each of the cases of loading in a first range and the second range on a placement surface. The load meter includes a mode determination unit 102 for determining whether a place on which a load is applied is in the first range or is in the second range, for the placement surface; and a load value calculating unit 104 for calculating the load value, on the basis of a detection value of the load sensor. The load value calculating unit 104 selects the calibration information which is used, from the calibration tables A361, B362, in accordance with the determination result by the mode determination unit 102 and applies the calibration table selected to the detection value of the load sensor to thereby calculate the load value. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a load cell, and more particularly to a load cell that requires calibration work.

  Conventionally, the calibration of the load value has been performed at one place. As a precondition for performing calibration at one place, a load meter without displacement is required.

  In other words, in a load cell that is affected by the displacement, the accuracy is guaranteed when the load value is measured at the same A point in the calibration at a certain A point, but the accuracy is guaranteed when the load value is measured at a different B point. Cannot guarantee.

  On the other hand, as a correction technique, as in the electronic balance of Patent Document 1, calibration is performed at a center and a position away from the center by a distance L, a deviation error is calculated, and correction is performed according to the distance L from the center. There is something like that.

JP-A-1-216217

  In order to prevent the load meter from being affected by the displacement, it is necessary to harden the sheet metal on the mounting surface or to make the load sensor highly accurate. Therefore, there is a problem that the cost is increased and the weight of the apparatus is increased.

  Further, in the conventional technique such as Patent Document 1, since the relationship between the distance L from the center and the deviation error must be clear, it may be difficult to accurately measure the load value.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a load cell that can accurately measure a load value in a load cell that is affected by a displacement. That is.

  A load cell according to an aspect of the present invention includes a mounting surface having a first range and a second range in which a load can be applied, and at least one load sensor for detecting an amount of the load applied to the mounting surface And first calibration information and second calibration information that prescribe a value corresponding to the calibration value of the detection value of the load sensor for each of the cases when the load is applied to the first range and the second range. Storage means, discrimination means for discriminating whether the place where the load is applied to the placement surface is the first range or the second range, and the detection value of the load sensor A first calculating means for calculating a load value representing at least one of the weight of the measurement object placed on the placement surface and the amount of force applied to the placement surface; The first calculation means follows the discrimination result by the discrimination means. Select calibration information to be used among the first calibration information and the second calibration data and calculates the load value by applying the calibration information selected on the detected value of a load sensor.

  Preferably, the first calibration information defines a calibration value with respect to a detection value when the load is applied to the first range as a corresponding value, and the first calculation means has a determination result in the first range. In this case, the first calibration information is selected, and the calibration value associated with the detection value of the load sensor in the first calibration information is determined as the load value.

  Alternatively, the second configuration information defines the calibration value for the detection value when the load is applied to the second range as a corresponding value, and the first calculation means determines that the determination result is within the second range. In some cases, it is desirable to select the second calibration information, and to determine, as the load value, the calibration value associated with the detection value of the load sensor in the second calibration information.

  Preferably, the second calibration information is an actual load value and a calibration value after replacement when the detected value when the load is applied to the second range is replaced with the calibration value specified by the first calibration information. The first calculation means associates with the detection value of the load sensor in the first calibration information when the determination result is in the second range. The load value is calculated by correcting the obtained calibration value with the error value associated with the calibration value in the second calibration information.

  Preferably, the first range and the second range are respectively a first part of the placement surface that contacts the soles of the subject for weight measurement and a muscle strength measurement of a specific body part. Corresponds to any one of the second parts in contact with a part of the specific body part of the measurement subject.

  Preferably, when it is determined that a load is applied to a range corresponding to the first portion of the first range and the second range, the determination unit determines the weight measurement mode, and When it is determined that a load has been applied to the corresponding range, the mode is determined as the muscle strength measurement mode. When the load meter is determined as the weight measurement mode, the calculated load value is output as the weight of the subject. The output means for outputting the calculated load value as the muscle strength value in a specific body part when the muscle strength measurement mode is determined.

  Preferably, based on a plurality of electrodes to be brought into contact with the soles of the person to be measured and a weight value calculated when the weight measurement mode is determined and a bioimpedance obtained by the electrodes, the person to be measured And a second calculating means for calculating the body composition, and the output means further outputs the calculated body composition when it is determined as the body weight measurement mode.

  Preferably, the determination unit detects whether the place where the load is applied to the placement surface is in the first range or the second range by detecting whether the electrode is energized. Determine.

  Alternatively, the determining unit determines whether the place where the load is applied to the placement surface is the first range or the second range based on the difference in the output value from each load sensor. It is desirable.

  Alternatively, it is preferable that the determination unit determines whether the place where the load is applied to the placement surface is the first range or the second range based on an input from the user.

  According to the present invention, a load value can be measured with high accuracy even with a load cell that is affected by an offset.

It is a figure which shows an example of the external appearance of the body composition meter as a load meter in embodiment of this invention. It is a top view of the leg unit of the body composition meter in the embodiment of the present invention. It is sectional drawing in the III-III line of the leg unit in the body composition meter shown in FIG. It is a figure which shows typically the position where a load is applied with respect to the mounting surface of the body composition meter in embodiment of this invention. It is a block diagram which shows the structural example of the body composition meter in embodiment of this invention. It is a functional block diagram which shows the function which CPU100 of the body composition analyzer in embodiment of this invention performs. (A), (B) is a figure which shows the example of a data structure of the calibration table A and the calibration table B in embodiment of this invention, respectively. It is a figure which shows the production | generation principle of the calibration tables A and B in embodiment of this invention. It is a flowchart which shows the load value measurement process in embodiment of this invention. It is a figure which shows the example of a data structure of the error value table in the modification 1 of embodiment of this invention. It is a flowchart which shows the load value measurement process in the modification 1 of embodiment of this invention.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment]
The load meter in the present embodiment represents at least an apparatus having a function of measuring a load value. In the present embodiment, the “load value” is a generic name for the weight (mass) of the person or object to be measured and the value representing the amount of force in weight. The latter value indicates, for example, the amount of force in a specific body part of a person (hereinafter referred to as “muscle strength value”).

  When measuring the weight of a person, that is, the body weight, the load cell may further have a function of measuring the body composition of the measurement subject based on the measured body weight.

  In the present embodiment, the load meter is described as a body composition meter capable of measuring a load value (including body weight) and a body composition. In addition, “body composition” represents the ratio or amount of a component constituting the body (tissue constituting the body). For example, body fat percentage, muscle percentage, lean body mass, body fat mass, muscle mass Including at least one of them.

<About the overview>
First, an overview of the body composition meter in the present embodiment will be described with reference to FIGS. The body composition meter in the present embodiment can be operated in the body weight measurement mode and the muscle strength measurement mode.

  FIG. 1 is a diagram showing an example of an appearance of a body composition meter 1 according to an embodiment of the present invention. FIG. 2 is a top view of the lower limb unit 3 of the body composition meter 1. FIG. 3 is a cross-sectional view taken along line III-III shown in FIG.

  Referring to FIG. 1, body composition meter 1 electrically connects upper limb unit 2 that a user can hold with both hands, lower limb unit 3 on which both legs of the user can be placed, and upper limb unit 2 and lower limb unit 3. And a cable 4 for performing the above.

  The upper limb unit 2 includes a plurality of electrodes E11, E12, E21, E22 (hereinafter collectively referred to as “upper limb electrodes”), an operation unit 32 for receiving instructions from the user, measurement results and various information. A display unit 34 for displaying is provided.

  The left hand grip of the upper limb unit 2 is provided with electrodes E11 and E21, and the right hand grip is provided with electrodes E12 and E22. The electrodes E11 and E12 are current application electrodes. The electrodes E21 and E22 are electrodes for voltage measurement.

  1 and 2, the lower limb unit 3 includes a plurality of electrodes E13, E14, E23, E24 (hereinafter collectively referred to as “lower limb electrodes”) and a plurality of load sensors 11, 12 , 13, 14 are included. Electrodes E13 and E14 are electrodes for current application, and electrodes E23 and E24 are electrodes for voltage measurement.

  Referring to FIG. 3, the lower limb unit 3 is surrounded by a top cover 301, a bottom cover 302, and foot covers 305 and 306, and a frame (for example, a sheet metal) 303, a substrate 304, a load sensor are included therein. 11, 12, 13, and 14 are provided.

  A protruding portion 5 is disposed at the central portion on the top cover 301. The protrusion 5 functions as an auxiliary tool for placing the measurement subject's knee (back of the knee). The upper surface 501 of the protrusion 5 is formed in a curved shape, for example, so that the back of the knee can be easily pressed. A load is applied to the upper surface 501 of the protrusion 5 by pressing the back of the knee while the subject is in the sitting or supine position.

  Electrodes E13 and E23 are provided in a region 301L on the left side of the protruding portion 5 on the top cover 301, and electrodes E14 and E24 are provided in a region 301R on the right side of the protruding portion 5.

  In the case of the body composition meter 1 as in the present embodiment, the surfaces on which the measurement object can be placed in the lower limb unit 3 are the exposed surfaces (regions 301L and 301R) of the top cover 301 and the top surface 501 of the protrusion 5 including. Such a surface is referred to as a “mounting surface SF10”.

  The load sensors 11, 12, 13, and 14 detect the amount of load applied to the placement surface SF10 of the lower limb unit 3.

  FIG. 4 is a diagram schematically showing a position where a load is applied to placement surface SF10 of body composition meter 1 in the embodiment of the present invention.

  Referring to FIG. 4, in the present embodiment, body composition meter 1 has two sets of points (load A point and load B point) as places where a load can be applied. The point of load A indicates a position where a load is applied when measuring body weight or body composition. In other words, on the placement surface SF10, the position (position in the regions 301L and 301R) where the soles of the measurement subject are placed corresponds to the point A. A load point B indicates a position to which a load is applied when measuring the muscle strength of the muscles surrounding the leg (quadriceps (thigh) or knee joint). That is, on the placement surface SF10, the position where the back of the measurement subject is placed (the position within the upper surface 501 of the protrusion 5) corresponds to the B point.

  A range corresponding to the point of load A in the mounting surface SF10, that is, a place where a load can be applied at least when measuring the body weight is hereinafter referred to as “range A”. A range corresponding to the load point B in the mounting surface SF10, that is, a place where a load can be applied when measuring the muscle strength of the leg is hereinafter referred to as “range B”. In other words, the range A represents a region included in the regions 301L and 301R on the top cover 301, and the range B represents a region included in the upper surface 501 of the protruding portion 5.

  When a load is applied to the range A or the range B of the placement surface SF10, the top cover 301 is pushed down. As the top cover 301 is pushed down, the frame 303 is also pushed down. When the frame 303 is pushed down, the load sensors 11, 12, 13, and 14 detect the amount of force applied to the placement surface SF10.

  Each of the load sensors 11, 12, 13, and 14 includes, for example, a load cell using a strain gauge. When a force is applied, the applied force is detected as a potential. The potential detected by each load sensor is output to an electric circuit in the substrate 304. The load sensors 11, 12, 13, and 14 are not limited to load cells. For example, if the amount of force applied to the placement surface SF10 can be detected, a sensor using a spring or a piezo film, It may be a compression element, a displacement sensor, or the like.

  In the present embodiment, four load sensors are provided, but two or one may be provided.

<About configuration>
FIG. 5 is a block diagram illustrating a configuration example of the body composition monitor 1 according to the embodiment of the present invention.

  Referring to FIG. 5, in addition to the above-described configuration, body composition meter 1 includes an impedance measuring unit 24 for measuring the bioelectrical impedance of the measurement subject, and an A / D (A / D ( analog to digital) circuit section 26, power supply section 30, storage section 36 for storing various data and programs, communication I / F (interface) section 38, and CPU 100 for controlling each section and performing various calculations. Including.

  The impedance measuring unit 24 measures bioimpedance using the upper limb electrode and the lower limb electrode. The impedance measurement unit 24 detects a potential difference between at least the limbs (whole body) in a state where a weak current is applied between the limbs of the user, and measures the impedance from the detected potential difference.

  The impedance measuring unit 24 is controlled by the CPU 100 to switch electrodes. The impedance measuring unit 24 is connected to all of the electrodes E11 to E14 and E21 to E24, for example, and is selected by a changeover switch (not shown) for changing the electrodes in accordance with an instruction from the CPU 100 and a changeover switch. A constant current generating section (not shown) for supplying a constant current to at least one pair of current electrodes; Then, in a state where a constant current is applied to the user via the current electrode, the impedance is measured by detecting a potential difference between at least one pair of voltage electrodes selected by the changeover switch.

  The value measured by the impedance measuring unit 24 is output to the A / D circuit unit 26. The impedance value may be calculated by the CPU 100 based on the detected potential difference.

  The A / D circuit unit 26 converts the output signal from the impedance measurement unit 24 into a digital signal and outputs it to the CPU 100. Further, the electric signals from the load sensors 11, 12, 13, and 14 are converted into digital signals and output to the CPU 100.

  The operation unit 32 includes, for example, a plurality of buttons. The display unit 34 is configured by, for example, an LCD (Liquid Crystal Display).

Storage unit 36 includes, for example, a nonvolatile memory such as a flash memory.
The communication I / F unit 38 transmits / receives data and programs to / from an external device. Note that the body composition meter 1 has a writing unit (not shown) for reading data and programs stored in a removable recording medium and writing them in the storage unit 36 instead of / in addition to the communication I / F unit 38. ) May be provided.

A functional configuration of the CPU 100 will be described.
FIG. 6 is a functional block diagram illustrating functions executed by the CPU 100 of the body composition monitor 1 according to the embodiment of the present invention.

  Referring to FIG. 6, in the present embodiment, CPU 100 includes a mode determination unit 102, a load value calculation unit 104, a body composition calculation unit 106, and an output processing unit 108 as its functions.

  When the load on the placement surface SF10 is detected from the outputs from the load sensors 11, 12, 13, and 14, the mode determination unit 102 determines whether the load value measurement mode is the weight measurement mode or the muscle strength measurement mode. To do. Therefore, it is determined whether the place where the load is applied to the placement surface SF10 of the lower limb unit 3 is the range A or the range B. The mode discriminating unit 102 discriminates the weight measurement mode when the load on the range A is detected and the muscle strength measurement mode when the load on the range B is detected.

  In the present embodiment, the mode discriminating unit 102 discriminates a place where a load is applied by detecting whether or not the lower limb electrode is energized. That is, if the lower limb electrode is energized, it is considered that the measurement target (the person to be measured) is placed in the range A, and therefore, the weight measurement mode is determined. On the other hand, if the lower limb electrode is not energized, it is considered that the measurement target is not placed in the range A, and therefore, the muscle strength measurement mode is determined.

The mode discrimination result is output to the load value calculation unit 104 and the output processing unit 108.
The load value calculation unit 104 calculates the load value based on the mode discrimination result, the value (sensor detection value) based on the output values from the load sensors 11, 12, 13, and 14, and the calibration table A361 and the calibration table B362. To do.

  The calibration table A361 and the calibration table B362 are information that defines the calibration value of the sensor detection value when the load is applied to the range A and the range B, respectively. These are stored in the storage unit 36.

  In the present embodiment, the “sensor detection value” refers to a value (for example, each load) based on the signal after the electrical signals from the load sensors 11, 12, 13, 14 are converted by the A / D circuit unit 26. (Average value or total value of output values from the sensor), and in a device that does not require calibration work, this value corresponds to the load value to be measured.

  FIGS. 7A and 7B are diagrams showing examples of data structures of the calibration table A361 and the calibration table B362, respectively, according to the embodiment of the present invention.

  Referring to FIG. 7A, calibration table A361 defines the calibration value for each sensor detection value in range A. That is, the sensor detection value is associated with the calibration value (hereinafter also referred to as “A point calibration value”) in the case of the load applied to the point A shown in FIG.

  Referring to FIG. 7B, calibration table B362 defines calibration values for the sensor detection values in range B. That is, the sensor detection value is associated with the calibration value (hereinafter also referred to as “B point calibration value”) in the case of the load on the B point shown in FIG.

  Such calibration tables A361 and B362 are generated for each body composition meter 1 before shipment. Here, how each calibration table is generated will be described.

  FIG. 8 is a diagram showing a generation principle of the calibration tables A361 and B362 in the embodiment of the present invention.

  Referring to FIG. 8, two lines 90 </ b> A and 90 </ b> B are shown in a graph in which the horizontal axis represents the weight of the weight (unit: kg) and the vertical axis represents the sensor detection value. A line 90A shows an example of the relationship between the weight of the weight and the sensor detection value when the weight is placed on the point A (range A) shown in FIG. A line 90B shows an example of the relationship between the weight of the weight and the sensor detection value when the weight is placed on the point B (range B) shown in FIG.

  For example, when a weight of 40 kg is placed on the range A of the placement surface SF10, the sensor detection value is 4000, and when a weight of the same weight is placed on the range B of the placement surface SF10, the sensor detection value is 4400. Suppose that In this case, the load meter records the point A calibration value corresponding to the sensor detection value 4000 in the calibration table A361 as 40 (kg). The B point calibration value corresponding to the sensor detection value 4400 in the calibration table B362 is recorded as 40 (kg).

  In this manner, the calibration table A361 and the calibration table B362 are generated by placing weights of various weights in the ranges A and B and associating the sensor detection values with the weights of the weights placed thereon. .

  In the present embodiment, the calibration information for each of the ranges A and B is held in a table format. However, the calibration information is not limited, and may be held by, for example, two correlation equations.

  Referring to FIG. 6 again, the load value calculation unit 104 selects the calibration table A361 when receiving the determination result from the weight measurement mode. In the calibration table A361, a calibration value associated with the sensor detection value obtained this time is calculated as a load value. On the other hand, when the determination result from the muscle strength measurement mode is received, the calibration table B362 is selected. Then, in the calibration table B362, the calibration value associated with the sensor detection value obtained this time is calculated as the load value.

  The calculated load value is output to the output processing unit 108. In the present embodiment, in the weight measurement mode, the calculated load value is also output to the body composition calculation unit 106.

  The body composition calculation unit 106 calculates a body composition for the whole body or each part by applying a known algorithm to the input load value (that is, the weight of the person to be measured) and the detected bioelectrical impedance. Specifically, for example, the body fat percentage (% FAT) of the whole body is calculated using the following formulas (1) and (2). In the case of calculating the body fat percentage, attribute information (for example, age, height, etc.) of the measurement subject may be further used.

% FAT = (W−FFM) / W · 100 (1)
FFM = a · H ² / Zw + b · W + c · Ag + d (2)
(Where FFM: lean body mass, W: body weight (load value), H: height, Zw: whole body impedance, Ag: age, a to d: constant)
It should be noted that the whole body impedance is between the detected electrodes E21 and E22 and the electrodes E23 and E24 in a state where a current is applied from the electrodes E11 and E12 to the electrodes E13 and E14 and applied to the whole body of the subject. It is a value measured based on the potential difference.

The calculated body composition (for example, body fat percentage) is output to the output processing unit 108.
The output processing unit 108 outputs the calculated load value and body composition. Specifically, when the output processing unit 108 receives the determination result from the weight measurement mode, the output processing unit 108 displays both the load value and the body composition or only the body composition on the display unit 34. In the weight measurement mode, the load value is displayed as the weight. When the output processing unit 108 receives the determination result from the muscle strength measurement mode, the output processing unit 108 displays the load value on the display unit 34 as the muscle strength value of the leg.

  The functions of the units illustrated in FIG. 6 may be realized by executing software stored in the storage unit 36, or at least one of these may be realized by hardware. .

  The body composition meter 1 measures the body composition using both the upper limb electrode and the lower limb electrode, but may measure the body composition using only the lower limb electrode. That is, the body composition meter 1 may be configured not to include the upper limb electrode or the upper limb unit 2 including the upper limb electrode. In that case, the operation part 32 and the display part 34 are provided in the leg unit 3, for example.

<About operation>
Next, a load value measurement process that is the most characteristic process executed by the body composition meter 1 will be described.

  FIG. 9 is a flowchart showing a load value measurement process in the embodiment of the present invention. The process shown in the flowchart of FIG. 9 is stored in advance in the storage unit 36 as a program, and the function of the load value measurement process is realized by the CPU 100 reading and executing this program.

  Referring to FIG. 9, CPU 100 determines whether or not a load is applied when the power is turned on (step S102). Whether or not a load is applied can be determined by detecting a change in the sensor detection value. If no load is applied, the process ends (NO in step S102).

  If it is determined that a load is applied (YES in step S102), mode determination unit 102 determines whether or not the lower limb electrode is energized (step S104). Specifically, for example, the presence or absence of energization may be determined by applying a weak current to the electrodes E13 and E14 of the lower limb unit 3 and detecting whether or not a potential difference is detected at the electrodes E23 and E24.

  If it is determined that the lower limb electrode is energized (YES in step S104), the process proceeds to step S106. If it is determined that power is not supplied (NO in step S104), the process proceeds to step S112.

  In step S106, the mode determination unit 102 determines that the load is applied to the point A shown in FIG. 4, and sets the current measurement to the weight measurement mode. When the weight measurement mode is set, the load value calculation unit 104 selects (reads out) the calibration table A361 stored in the storage unit 36. Then, using the calibration table A361, the weight of the measurement subject is measured by replacing the sensor detection value with the point A calibration value (step S108). The output processing unit 108 outputs the measured weight (step S110).

  Next, CPU100 determines whether the operation part 32 received the instruction | indication of the body composition measurement from the user (step S112). When it is determined that a body composition measurement instruction has been input (YES in step S112), body composition calculation unit 106 performs a process of measuring bioimpedance using an upper limb electrode and a lower limb electrode by a known method. Then, the body composition of the measurement subject is calculated by applying at least the measured impedance and the weight value measured in step S108 to a predetermined algorithm (step S114). The body fat percentage can be calculated by the above formulas (1) and (2), for example. The output processing unit 108 outputs the measured body composition (step S116).

  If there is no body composition measurement instruction (NO in step S112), the load value measurement process is terminated.

  On the other hand, in step S118, the mode determination unit 102 determines that the load is applied to the point B shown in FIG. 4, and sets the current measurement to the muscle strength measurement mode. When the muscle strength measurement mode is set, the load value calculation unit 104 selects (reads out) the calibration table B362 stored in the storage unit 36. Then, by using the calibration table B362, the muscle strength value at the leg is measured by replacing the sensor detection value with the B point calibration value (step S120). The output processing unit 108 outputs the measured muscle strength value (step S122).

  As described above, according to the present embodiment, whether a load is applied to the range A (point A) on the placement surface SF10 using the lower limb electrode that the body composition meter has conventionally provided, or the range B It is possible to automatically determine whether a load is applied to (B point). Further, since one of the two calibration tables A361 and B362 is selected according to the determination result, the load value (weight or muscle strength value) can be measured simply and accurately. Therefore, even with an inexpensive configuration, it is possible to reduce the deviation error in load value measurement.

  Moreover, in this Embodiment, it is an apparatus which has two measurement modes, and each mode respond | corresponds to the range (A or B) which can apply a load. Therefore, the measurement mode can be determined by specifying the range where the load is applied. Thereby, after the power is turned on, the person to be measured explicitly puts the measurement result of the load value on the weight value simply by placing it on the range A of the placement surface SF10 or pressing the back of the knee against the upper surface 501 of the protruding portion 5. Or it can also be displayed as a muscular strength value.

<Modification 1>
In the above embodiment, the two calibration tables A and B defining the calibration value of the sensor detection value are used for each of the cases where the load is applied to the range A and the range B. However, as long as one calibration information (table) is a value corresponding to the calibration value of the sensor detection value, the calibration value itself of the sensor detection value may not be specified.

  Specifically, for example, one piece of calibration information is information (same as the calibration table A361 in the embodiment) defining the calibration value of the sensor detection value when the load is applied to the range A. On the other hand, when the load is applied to the range B, an algorithm (error value) for calculating an accurate load value (weight of weight) from each calibration value defined in the calibration table A is displayed as “sensor detection”. Information defined as “a value corresponding to a calibration value” may be used.

Only the parts different from the above embodiment will be described below.
FIG. 10 is a diagram showing a data structure example of the error value table 363 in the first modification of the embodiment of the present invention.

  Referring to FIG. 10, error value table 363 shows the actual load value (weight of weight) when the sensor detection value at the time of load in range B is replaced with the calibration value specified in calibration table A361. And an error value between the calibration value after replacement. The error value table 363 is created, for example, by calculating an error with respect to an average point A calibration value from a plurality of body composition meter (load meter) samples.

  The error value stored in the error value table 363 may indicate the ratio between the A point calibration value and the weight weight (A point calibration value / weight weight, or weight weight / A point calibration value). Alternatively, the difference between the A point calibration value and the weight of the weight may be indicated. In this modification, for example, the error value indicates the weight of the point A calibration value / weight.

  FIG. 11 is a flowchart showing a load value measurement process in Modification 1 of the embodiment of the present invention. In the flowchart of FIG. 11, the same step number is attached to the same process as the process shown in FIG. 9. Therefore, description thereof will not be repeated.

  Referring to FIG. 11, in the present modification, the process of step S120 # is executed instead of the process of step S120 of FIG. It is assumed that the process of step S120 # is executed by “load value calculation unit 104 #”.

  In step S120 #, the load value calculation unit 104 # calculates a load value using both the calibration table A361 and the error value table 363 stored in the storage unit 36. Specifically, in the calibration table A361, the point A calibration value associated with the sensor detection value is read. In the error value table 363, an error value associated with the read point A calibration value is read. By dividing and correcting the read calibration value of the point A by the read error value, the load value at the point B, that is, the muscle strength value at the leg is calculated.

  As described above, the embodiment can be provided as long as there is one calibration table and error value table without using two calibration tables defining the calibration values for the ranges A and B as in the above embodiment. Similarly to the above, it is possible to accurately measure the load value at point B, that is, the muscular strength value at the leg.

<Modification 2>
In the said embodiment, although the mode was discriminate | determined by detecting the presence or absence of electricity supply of a leg electrode, it is not limited. For example, mode input may be received from the user (physician or person to be measured) via the operation unit 32.

  Alternatively, the mode may be determined based on a difference in output values from the load sensors 11, 12, 13, and 14. In this case, in the lower limb unit 3, four load sensors 11, 12, 13, and 14 are provided asymmetrically from the center point. It should be noted that the number of load sensors is not limited to four as long as it is plural, and the four load sensors may be provided symmetrically from the center point.

  Specifically, for example, it is detected whether the ratio of the output values of the four load sensors 11, 12, 13, and 14 is equal (1: 1: 1: 1). If they are equal, the load on the range A, that is, the weight measurement mode is determined. If they are not equal (for example, 1: 1: 2: 2, etc.), it can be determined that the load to the range B, that is, the muscle strength measurement mode.

<Modification 3>
In the above-described embodiment, a body composition meter is employed as an example of a load meter. However, as described above, the body composition meter may not have a function of measuring a body composition. In addition, when not having the function of measuring the body composition, the upper limb electrode, the lower limb electrode, and the impedance measuring unit 24 are not provided. Therefore, in such a case, it is effective to determine whether the measurement mode is the weight measurement mode or the muscle strength measurement mode by the processing of the second modification.

  Moreover, in the said embodiment, although it had the body weight measurement mode and the muscular strength measurement mode, you may have only any one mode. That is, the load meter may be a mere weight scale or a strength meter. In the case of a weight scale, the protrusion 5 does not exist, and the mounting surface may be a flat surface. In the case of a strength meter, the upper surface of the protrusion 5 may have a shape with a wider width than the upper surface 501 shown in the embodiment.

  For example, in the case of a weight scale, when the placement surface is wider than the range in contact with the sole of the person being measured, a load is applied when an adult measures weight and when a child measures weight. The range you get may be different. That is, when an adult measures weight, a load is applied to the position corresponding to the above point B, and when a child measures weight, a load is applied to a position closer to the center, such as the above point A. It is done. Even in such a case, the load value measurement process of the above embodiment is used to determine the range to which the load is applied, and to use one of the calibration tables A361 and B362 according to the determined range. The calculated load value can be calculated.

  It should be noted that the place where the load is applied on the flat mounting surface may deviate from the preset range where the load can be applied, but the calibration table corresponding to the range closer to the place where the load was applied. The load value may be calculated using

  Further, three or more ranges and a calibration table may be set as places where a load can be applied.

  Moreover, the process of the above-described embodiment can be applied not only to a scale with a human being as a measurement object, but also to a scale (for example, a kitchen scale) having a measurement object as an object.

In addition, you may combine at least any one of the modifications 1-3.
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 Body composition meter (load meter), 2 upper limb unit, 3 lower limb unit, 4 cable, 5 protrusion, 11, 12, 13, 14, load sensor, 24 impedance measurement unit, 26 A / D circuit unit, 30 power supply unit , 32 operation unit, 34 display unit, 36 storage unit, 38 communication I / F unit, 100 CPU, 102 mode discrimination unit, 104 load value calculation unit, 106 body composition calculation unit, 108 output processing unit, 301 top cover, 302 Bottom cover, 303 frame, 304 substrate, 305, 306 foot cover, 361 Calibration table A, 362 Calibration table B, 363 Error value table, E11, E12, E13, E14, E21, E22, E23, E24 Electrode.

Claims (10)

A mounting surface having a first range and a second range on which a load can be applied;
At least one load sensor for detecting the amount of load applied to the mounting surface;
First calibration information and second calibration information that prescribe a value corresponding to a calibration value of a detection value by the load sensor are stored in advance for each of cases where the load is applied to the first range and the second range. Storage means for
A discriminating means for discriminating whether the place where the load is applied to the placement surface is the first range or the second range;
In order to calculate a load value representing at least one of the weight of the measurement object placed on the placement surface and the amount of force applied to the placement surface based on the detection value of the load sensor First calculating means,
The first calculation means selects calibration information to be used from the first calibration information and the second calibration information according to the determination result by the determination means, and the selected calibration information is detected by the load sensor. A load cell that calculates the load value by applying to the value. The first calibration information defines a calibration value for a detection value when loaded to the first range as the corresponding value,
The first calculation means selects the first calibration information when the determination result is in the first range, and is associated with the detection value of the load sensor in the first calibration information. The load cell according to claim 1, wherein the calibration value is determined as a load value. The second configuration information defines a calibration value for a detection value when loaded to the second range as the corresponding value,
When the determination result is in the second range, the first calculation unit selects the second calibration information, and associates the second calibration information with the detection value of the load sensor. The load cell according to claim 2, wherein the determined calibration value is determined as a load value. The second calibration information includes an actual load value and a calibration value after replacement when a detection value when the load is applied to the second range is replaced with a calibration value defined by the first calibration information. Is defined as the corresponding value,
When the determination result is in the second range, the first calculation means calculates a calibration value associated with a detection value of the load sensor in the first calibration information. The load cell according to claim 2, wherein the load value is calculated by correcting with an error value associated with the calibration value in the calibration information.   The first range and the second range are respectively a first part of the placement surface that contacts the soles of the person to be measured for weight measurement, and a muscle strength measurement of a specific body part. The load cell according to any one of claims 2 to 4, wherein the load cell corresponds to any one of a second part in contact with a part of the specific body part of the measurement subject. When it is determined that a load is applied to a range corresponding to the first portion of the first range and the second range, the determination unit determines the weight measurement mode, and the second range When it is determined that a load is applied to the range corresponding to the part, it is determined that the muscle strength measurement mode,
The load meter outputs the calculated load value as the weight of the person to be measured when determined as the weight measurement mode, and outputs the calculated load value when determined as the muscle strength measurement mode. The load cell according to claim 5, further comprising output means for outputting as a muscle strength value in the specific body part. A plurality of electrodes to be in contact with the soles of the subject,
And a second calculating means for calculating the body composition of the person to be measured based on the calculated load value and the bioelectrical impedance obtained by the electrode when the weight measuring mode is determined. Prepared,
The load meter according to claim 6, wherein the output means further outputs the calculated body composition when it is determined that the weight measurement mode is selected.   The discriminating means detects whether the electrode is energized, so that the place where the load is applied to the placement surface is either the first range or the second range. The load cell according to claim 7, wherein the load cell is determined.   Whether the place where the load is applied to the placement surface is the first range or the second range based on a difference in output values from the load sensors. The load cell according to any one of claims 1 to 6, wherein:   The determination means determines, based on an input from a user, whether the place where the load is applied to the placement surface is the first range or the second range. The load cell according to any one of 1 to 6.

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