JP2022088499A - Hardness meter and hardness measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hardness meter which estimates hardness stably regardless of compression intensity.

SOLUTION: A hardness meter comprises: a movable portion which is pressed continuously against a measuring subject; a sensor which outputs an output signal which reflects reaction force at a part of the measuring subject, the part contacting with the movable portion; a power mechanism for subjecting the movable portion to piston motion; and a hardness estimation unit which estimates hardness of the measuring subject based on an alternating-current component of the output signal generated by the piston motion of the movable portion.

SELECTED DRAWING: Figure 5

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a hardness tester that estimates the hardness of an object.

Traditionally, it is often useful to measure the hardness of an object. For example, in the medical field and the beauty field, it is desired that the hardness of the human body can be measured. In the medical field,
By measuring the hardness at a predetermined location, it is possible to determine skin ulcers on the supporting surface caused by bedridden in the same posture for a long period of time, skin edema due to changes in organs, and strong skin symptoms. At acupuncture and osteopathy clinics, the effect of acupuncture and manipulative treatment on softening muscles can also be determined. Further, in the field of cosmetology, by measuring the hardness of a predetermined portion, it is possible to determine the degree of disease progression and the effect of drug treatment.

For such applications, a measuring instrument called a durometer has been conventionally used, in which the degree to which the object is dented when the object is pressed with a constant force is used as an index of hardness. Also, further
A tactile sensor has been developed that obtains information on changes in the resonance state when a mechanical vibrating part comes into contact with an object and outputs this as hardness information of the object (see Patent Document 1).

Japanese Unexamined Patent Publication No. 10-062328

The problem of the above-mentioned durometer is that the degree of denting of the object, which is the measurement result, changes depending on the force with which a person presses the object. That is, even for the same object, the estimated hardness differs between when lightly pressed and when strongly pressed. Therefore, the present invention solves this problem by a hardness tester provided with a mechanism for actively periodically moving the pressure sensor in addition to the mechanism of the durometer.

One aspect of the present invention is a sensor that outputs an output signal that reflects a reaction force at a movable portion that is continuously pressed against the object to be measured and a contact portion of the movable portion of the object to be measured, and a piston motion of the movable portion. The hardness meter is characterized by comprising a power mechanism for causing the measurement, and a hardness estimation unit for estimating the hardness of the object to be measured based on the AC component of the output signal generated by the piston movement of the movable portion.

Another aspect of the present invention is a first step of vibrating the movable part and a second step of acquiring a sense signal based on the reaction force from the measurement object when the movable part is brought into contact with the measurement object. A hardness measuring method comprising:, a third step of acquiring an AC component of a sense signal, and a fourth step of estimating the hardness of an object to be measured based on the amplitude of the AC component. Is.

According to the present invention, in the hardness tester, the hardness can be estimated only from the output value of the pressure sensor without depending on the strength pressed by the operator. In addition, problems, configurations, and effects other than those described above will be clarified by the following description of the examples.

It is a block diagram of the whole composition of a bio-hardness meter. It is explanatory perspective figure of the structural example of a measuring device (gun type). It is explanatory perspective figure of the structural example of the measuring apparatus (T-shaped). It is a schematic diagram of the operation principle of a measuring device. It is a schematic diagram of the voltage waveform of the magnetic sensor of the biohardness meter. It is a schematic diagram which converted the voltage waveform of the magnetic sensor of a biohardness meter into a force. It is a principle explanatory drawing of the method of estimating the hardness. It is a schematic diagram which estimates the hardness by fixing a DC component from the output waveform of a biohardness meter. It is a schematic diagram which estimates the hardness by fixing the AC component from the output waveform of the biohardness meter. It is a graph which shows the result of estimating the hardness. It is an example of a flowchart showing the entire flow of processing by a biohardness tester. It is a figure of the subject registration screen. It is a figure which displayed the hardness and the hardness map estimated on the result display screen. It is a table diagram which shows the example of the correspondence table of an Example. It is a table diagram which shows the other example of the correspondence table of an Example. It is a figure which displayed the hardness map before and after the treatment on the result display screen. It is a schematic diagram which shows the measuring device for position estimation.

Hereinafter, examples of the present invention will be described with reference to the accompanying drawings. The accompanying drawings show specific examples in accordance with the principles of the invention, but these are for the purpose of understanding the invention and are by no means used for a limited interpretation of the invention. .. In addition, the same reference number may be assigned to the common configuration in each figure.

The following examples relate to a technique for calculating the hardness of an object to be measured. Hardness is an index showing the hardness of an object to be measured, and means elasticity. Hereinafter, a living body such as a human body will be described as an example as a measurement object, but the present invention is not limited to this. For example, the hardness tester in the following examples may be applied to an object other than a living body.

FIG. 1 is an overall configuration diagram of a biohardness tester. The biohardness meter 1000 includes a measuring device 1 and a hardness calculating device 2. In addition, in the measuring device 1 of FIG. 1, a part of the configuration is omitted as compared with the measuring device 1 of FIGS. 2, 3, and 4. Here, the configuration and operating principle of the measuring device 1 will be described with reference to FIGS. 2, 3 and 4.

FIG. 2 shows the configuration of an example of the measuring device 1. The measuring device 1 includes a main body portion 14 having a receiving coil 11 (magnetic field detecting means) and a movable portion 15 having a transmitting coil 12 (magnetic field generating means).
, A spring 13 (elastic body), a battery 16, a motor 17, and a vertically movable portion 18. The motor 17 driven by the battery 16 has a configuration in which the vertically movable portion 18 is moved by a piston by, for example, a crank structure. The receiving coil 11 and the transmitting coil 12 are collectively referred to as a magnetic sensor 19. The magnetic sensor 19 outputs reaction force information corresponding to the reaction force at the contact portion of the measurement object 150 with the movable portion 15.

The contact portion 20 of the movable portion 15 is a portion where the measurement object 150 is pressed against the measurement object 150 so as to be recessed during hardness measurement (calculation), and is a contact surface between the movable portion and the target portion. note that,
The main body portion 14 and the movable portion 15 have rigidity. The object to be measured 150 is, for example, an object for which the hardness of a human torso or the like is to be measured.

The magnetic sensor 19 outputs voltage information corresponding to the magnitude of the reaction force of the measurement object 150 according to the pressure applied to the measurement object 150 by the measuring device 1. Therefore, the receiving coil 11 and the transmitting coil 12 are arranged so as to face each other. And the main body 14
A spring 13 having a spring constant of K'(known) is arranged between the movable portion 15 and the movable portion 15 (see FIG. 2).

The spring 13 may be replaced with a spring having the same shape and a larger wire diameter. This makes it possible to measure the hardness of the deep layer position of the object. In the past, there was a problem that only the hardness on the skin surface could be measured, and information up to the deep skin layer could not be dealt with. On the other hand, according to the configuration, it may be possible to measure the hardness of not only the skin surface but also the subcutaneous tissue and muscles up to the deep skin layer.

FIG. 3 shows the configuration of another example of the measuring device 1. In FIG. 2, the entire housing is L-shaped, but it may be T-shaped or pencil-shaped so that the operator can easily hold it. FIG. 3 shows an example of a T-shape. In FIG. 3, the same reference numbers are assigned to the configurations common to those in FIG. The position measuring device 3 including the 3-axis receiving coil 301 and the transmitting coil 302 will be described later.

The operation of the magnetic sensor 19 and peripheral parts will be described with reference to FIG. First, the AC oscillation source 31 generates an AC voltage having a specific frequency (for example, 20 kHz). The AC voltage is converted into an AC current having a specific frequency by the amplifier 32, and the converted AC current flows through the transmission coil 12. The magnetic field generated by the alternating current flowing through the transmitting coil 12 generates an induced electromotive force in the receiving coil 11.

The AC current generated in the receiving coil 11 by the induced electromotive force (the frequency is the same as the frequency of the AC voltage generated by the AC oscillation source 31) is amplified by the preamplifier 33, and the amplified signal is input to the detection circuit 34. .. The detection circuit 34 detects the amplified signal at a specific frequency or a double frequency generated by the AC oscillation source 31. Therefore, the output of the AC oscillation source 31 is introduced into the reference signal input terminal of the detection circuit 34 as the reference signal 35. An operation method using a full-wave rectifier circuit may be used instead of the detection circuit 34. The voltage information (output signal) from the detection circuit 34 (or rectifier circuit) is introduced into the drive circuit 21 (see FIG. 1) of the hardness calculation device 2 after passing through the low-pass filter 36.

The measurement object 150 is modeled by a spring 37 (a) having a spring constant K and a dashpot (damper) 37 (b) having a dashpot coefficient G. The magnetic sensor 19 including the receiving coil 11 and the transmitting coil 12 is pressed against the measurement object 150. It is desirable that there is a relationship of K'> K between the spring constant K'of the spring 13 and the spring constant K of the object to be measured 150. Otherwise, when the main body portion 14 is pressed, the main body portion 14 and the measurement object 150 may come into contact with each other at the contact portion 20.

Next, returning to FIG. 1, the hardness calculation device 2 will be described. The hardness calculation device 2 is a computer device. The hardness calculation device 2 includes a drive circuit 21, a microprocessor 23, a storage unit 24, a voice generation unit 25, a display unit 26, a power supply unit 27, an input unit 28, and a position estimation drive circuit 29. ..

The microprocessor 23 is realized by, for example, a CPU (Central Processing Unit). The microprocessor 23 includes a voltage waveform generation unit 231 and an abnormal waveform detection unit 232.
, Voltage / pressure conversion unit 233, hardness estimation unit 234, determination unit 235, and position estimation unit 23.
6 and. The processing unit of the microprocessor 23 can be realized by various programs. For example, various programs stored in the storage unit 24 are expanded in a memory (not shown) of the hardness calculation device 2. The microprocessor 23 executes a program loaded in the memory and performs predetermined processing and calculation. Hereinafter, the processing contents of each processing unit of the microprocessor 23 will be described.

The voltage waveform generation unit 231 generates waveform information of the output voltage of the magnetic sensor obtained from the drive circuit 21. An example of the waveform of the output voltage of the magnetic sensor will be described in detail later in FIG.

The abnormal waveform detection unit 232 detects an abnormal waveform due to improper compression, such as when the compression is too weak or too strong, or when the compression direction is tilted with respect to the surface of the object. In estimating the hardness, it is necessary for the compression strength of the operator to be within an appropriate range, but the abnormal waveform detection unit 232
The purpose of this is to remove the waveform when it deviates from this appropriate range.

As a method for detecting an abnormal waveform, it can be determined that the abnormality is abnormal, provided that the magnitude of the DC component of the output signal is not within a certain range. Alternatively, it can be determined that the waveform is abnormal because the upper and lower limits of the AC component of the output signal cannot be detected. Hardness detection
In the range where such an abnormal waveform is not detected, it is performed based on the AC component of the output signal.

The voltage / pressure conversion unit 233 converts the output voltage of the air sensor into pressure information. The output voltage of the magnetic sensor changes according to the distance between the receiving coil 11 and the transmitting coil 12 in FIG. The distance between the two coils is equal to the length of the spring 13. The reaction force applied to the spring can be calculated from the distance contracted from the free length of the spring 13 and the spring constant of the spring 13 according to Hooke's law. Based on these relationships, the output voltage of the magnetic sensor is converted into pressure information. The conversion of the output voltage of the magnetic sensor into pressure information will be described in detail later in FIGS. 6 and 7.

Specifically, the magnetic flux at a predetermined distance between the two coils is calculated as follows. Let ds1 be a minute line element on the receiving coil 11 and ds2 be a minute line element on the transmitting coil 12. Also, ds
Let r be the position vector of ds2 seen from 1. At this time, the mutual inductance M ₁₂ between the receiving coil 11 and the transmitting coil 12 is calculated by the following equation (Neumann's formula). μ is the magnetic permeability.

Assuming that the current I flows through the receiving coil 11 and the number of turns of the receiving coil 11 is N, the magnetic flux φ in the transmitting coil 12 is calculated by the following equation using M ₁₂ .

Similarly, the magnetic flux φ when the distance between the two coils is changed in predetermined distance increments is calculated.
The magnetic flux φ has a linear relationship with the output voltage of the magnetic sensor. Therefore, with these data,
A conversion curve between the distance between the two coils and the output voltage of the magnetic sensor can be created. Next, the displacement amount of the spring 13 is obtained by subtracting the distance between the two coils from the free length of the spring 13. A reaction force can be obtained by multiplying this displacement amount by the spring constant of the spring 13. From the above, it is possible to generate a conversion curve between the output voltage of the magnetic sensor and the reaction force.

≪Method of estimating hardness≫
The hardness estimation unit 234 will be described with reference to FIGS. 5 to 10.

FIG. 5 shows the output waveform of the magnetic sensor 19, where the horizontal axis represents time (seconds) and the vertical axis represents output voltage (V).
Is shown. When the operator puts the biohardness meter 1000 on the object to be measured 150 and gradually presses it, the waveform of the output voltage of the magnetic sensor 19 as shown in FIG. 5 is obtained. To simplify the conditions
The hardness of the object to be measured 150 is constant regardless of the depth, that is, the hardness is uniform (the same applies to FIGS. 6 to 9). Here, the slow fluctuation due to the pressure of the hand excluding the frequency component of the motor 17 is the DC component.
It is called V _D , and the amplitude of fast fluctuation with the frequency component of the motor 17 is called the AC component V _A. It can be seen that the DC component V _D increases as the pressure is applied little by little, and the AC component V _A gradually increases accordingly. This is because the voltage of the magnetic sensor 19 increases exponentially as the distance between the receiving coil 11 and the transmitting coil 12 decreases due to compression. A known analog or digital frequency filter may be used for extraction of the DC component and the AC component.

FIG. 6 is a waveform obtained by converting the waveform of the output voltage of the magnetic sensor 19 into a waveform of pressure by the voltage / pressure conversion unit 233 described above. The horizontal axis is time (seconds) as in FIG. 5, and the vertical axis is the converted pressure (N). In the pressure waveform, when the pressure is applied little by little, the DC component F _D becomes large, but the amplitude of the AC component F _AC is always constant. The point that the AC component is constant is the difference from the output voltage of the magnetic sensor in FIG. The estimated hardness is obtained based on this AC component F _AC .

When determining the actual hardness, prepare a plurality of objects having known hardness, measure each object with a biohardness meter 1000, and determine the amplitude of the above-mentioned AC component F _AC . by this,
A correspondence table of known hardness and AC component F _AC can be obtained. When an object of unknown hardness is measured and the AC component F _AC is obtained, it can be converted to hardness from this correspondence table. By interpolating the data in the correspondence table by linear interpolation or spline interpolation to obtain a conversion formula, even the AC component F _AC that is not in the correspondence table can be converted to hardness. The above correspondence table is created in advance and made into a database, and is stored as a database 1001 in the storage unit 24, for example. Hardness estimation unit 234 is a database 1001
The pressure obtained from the voltage / pressure conversion unit 233 is converted into hardness with reference to.

FIG. 7 is a principle explanatory diagram of a method for estimating hardness. Here, the reason why the AC component F _AC is regarded as the estimated hardness in the pressure waveform of FIG. 6 will be described with reference to FIG. 7. When the operator presses the measurement target with a constant force F ₀ , the motor 17 further gives a small periodic fluctuation of the amplitude A _C. Assuming that D is the pushing amount and ΔF is the amount of change (change width) of the force due to the periodic fluctuation of the amplitude A _C , in this case, the relationship of D: A _C = F ₀ : ΔF is established according to Hooke's law.

This means that ΔF differs depending on the hardness of the measurement target. That is, since the amplitude A _C is constant, when the object to be measured 150 is soft (the spring constant K of the object to be measured is small), the amount of pushing D is large, so that the force due to the amplitude A _C of the motor 17 with respect to F ₀ is applied. The change ΔF becomes smaller.
On the other hand, when the measurement target is hard (the spring constant K of the measurement target is large), the pushing amount D is small, so that the change ΔF of the force due to the amplitude A _C of the motor 17 with respect to F ₀ becomes large.

The above contents will be explained by an equation as follows. Assuming that the spring constant of the object to be measured 150 is K,
The pushing amount D [mm] when the operator pushes the biohardness meter 1000 with a certain force F is as follows according to Hooke's law.
F = KD

At that time, the contact portion 20 fluctuates up and down with a predetermined amplitude _AC by the motor 17. At this time, when the operator manually pushes in with a predetermined force F = F _D = K _D D, the force when the motor 17 reaches the highest position (D _D − _AC ) is as follows.
F _U = K (D _D - _AC ) = F-KA _C
Then, when the operator manually pushes in with a predetermined force F = F _D = K _D D, the force when the motor 17 reaches the lowest position (D _D + _AC ) is as follows.
_{FL =} K (D _D + _AC ) = F + KA _C

The difference in force between the highest position and the lowest position of the motor 17 F _AC (= AC component of force) is as follows.
F _AC = FL-F _U = _{2KA C}
Since A _C is constant, F _AC is proportional to the spring constant K of the object. Therefore, it can be seen that the F _AC increases as the object becomes harder. From this equation, it can be seen that if the objects have the same hardness, the AC component F _AC of the force is always constant regardless of the compression strength (DC component of the force).

A case where the hardness is estimated by using the output voltage of the magnetic sensor as it is as a force sensor will be described with reference to FIG. In this case, the voltage / pressure conversion unit 233 is omitted, and the magnetic sensor 1
The output voltage of 9 is treated as the pressure as it is. In this case, as shown in the waveform shown in FIG. 8, in the magnetic sensor, the AC component V _A increases as the DC component V _D increases (that is, as the compression intensity increases). As mentioned in the previous paragraph, this is the voltage / pressure conversion unit 233.
This is different from the point that the AC component of the force is always constant regardless of the DC component (compression strength) of the force.

The reason why the AC component is not constant is that the relationship between the output voltage and the force is not proportional in the magnetic sensor. Since the distance between the two coils between the transmitting coil 12 and the receiving coil 11 inside the hardness gauge is equal to the length of the spring 13 inside the hardness gauge, the distance between the two coils and the force have a linear relationship according to Hooke's law. On the other hand, the magnitude of the magnetic flux is the transmission coil 1
The distance between the two coils between 2 and the receiving coil 11 does not have a linear relationship, but a non-linear relationship in which the magnetic flux increases rapidly as the two coils approach each other. Therefore, the force and magnetic flux also have a non-linear relationship.
As the compression strength increases, the AC component increases.

Therefore, when the output voltage of the magnetic sensor is treated as the pressure as it is without implementing the voltage / pressure conversion unit 233, the alternating current of the voltage when the DC component V _D of the voltage is fixed to a constant value V _DC . Let the component V _AC be the estimated hardness. In this way, the hardness can be estimated independently of the non-linear characteristic between the magnitude of the magnetic flux and the distance between the two coils.

Specifically, the database 1001 of the storage unit 24 stores a correspondence table of the amplitude and hardness of V _AC when the DC component V _D is fixed to a constant value V _DC . At the time of measurement, the DC component V _D is monitored, and the amplitude of the AC component V _AC when the predetermined value V _DC is reached is acquired. Then, referring to the correspondence table, the hardness corresponding to the amplitude is obtained.

An example of how to determine the constant value _VDC will be described with reference to FIG. A range (A) in which the hardness tester is lightly touching the measurement object 150 (the DC component V _D of the voltage is small) when the measuring device 1 is gradually pressed against the measurement object 150 and pressed. Then, the AC component cannot be completely obtained. On the other hand, in the range (C) in which the hardness tester pushes the measurement object into a saturated state, the object becomes hard like a rigid body, so that an accurate value of the AC component cannot be obtained. That is, a constant value V _D
C may be set to the voltage in the range (B) between the above two extreme states so that the AC component can be appropriately obtained in the voltage waveform. Since it depends on the spring constant of the spring 13 inside the measuring device 1, it is necessary to redetermine the constant value V _DC after replacing the spring.

FIG. 9 shows another example. Based on the same idea as in FIG. 8, as shown in FIG. 9, the AC component V _A of the voltage.
The DC component V _DC of the voltage when is fixed at a constant value V _AC may be used as the estimated hardness. Also in this method, the hardness can be estimated without depending on the non-linear characteristic between the magnitude of the magnetic flux and the distance between the two coils. The setting of the DC component V _AC of the voltage is also in the same light contact state as the above-mentioned V _DC setting method (A).
It may be set as the DC component of the voltage in the range (B) sandwiched between the extreme states of the saturated state (C) by pressing strongly.

8 and 9 describe a method of estimating the hardness based on the AC component when the DC component is fixed or the DC component when the DC component is fixed when the voltage / pressure conversion unit 233 is not implemented. did. However, even when the voltage / pressure conversion unit 233 is provided, the AC component of the force may not always be constant depending on the nature of the measurement target. In this case, there is a merit of using the hardness estimation methods of FIGS. 8 and 9.

In FIG. 7, it is simply explained that the object for which the hardness is estimated has the same characteristics as the spring, but in practice, it is assumed that the measurement is performed on the living tissue such as the skin, muscle, and fat of the human body. To. The spring follows Hooke's law exactly, and the spring constant is constant regardless of the compression strength. However, due to the nature of living tissue, it is known that the spring constant (hardness) increases as the pressure is strongly applied. Therefore, when measuring a living tissue, the AC component _FD does not become constant as shown in FIG. 6 even after the output voltage of the magnetic sensor is converted into force, and increases as the compression becomes stronger. there's a possibility that. For this reason, the voltage / pressure converter 233
The hardness may be estimated based on the AC component when the DC component is fixed (see FIG. 8) or the DC component when the AC component is fixed (see FIG. 9). Further, if the spring constant (hardness) differs depending on the compression strength, several fixed values of the AC component and the DC component may be set.

FIG. 10 shows the result when the hardness is estimated by the method of FIG. 9 using the magnetic sensor 19 without implementing the voltage / pressure conversion unit 233. The three types of markers in the graph represent three measurers. The horizontal axis is the known hardness (without unit) measured by a durometer, and the vertical axis is the estimated hardness (V) obtained by the method of FIG. 9 by an electric hardness tester. From this graph, the estimated hardness and the data points of the known hardness are fitted by a polynomial to obtain a curve showing the relationship between the two. When the estimated hardness is obtained by the measurement of the electric hardness tester, it can be converted to the known hardness by substituting it into the curve.

Returning to FIG. 1, the storage unit 24 is a means for storing various information, for example, a RAM (Rando).
It is realized by m Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), etc. The storage unit 24 stores in advance the voltage / pressure conversion coefficient _Cmp calculated by the experiment. The voice generation unit 25 is a means for generating voice, and is realized by, for example, a speaker. The voice generation unit 25 generates a beep sound, for example, at the start and end of the measurement by the measuring device 1. The display unit 26 is a means for performing various displays, for example, an LCD.
It is realized by (Liquid Crystal Display) or CRT (Cathode Ray Tube) Display. The display unit 26 displays various waveforms, hardness of the object (for example, at least one of elasticity information and viscosity information), an indicator that visualizes the hardness of the object, and the like.

The display unit 26 displays the estimated hardness obtained by the hardness estimation unit 234. Further, as will be described later, this estimated hardness may be displayed as a color map at a measurement position on the surface of the living body. Here, the measurement position on the surface of the living body is estimated by the position estimation unit 236 from the data of the magnetic field reflecting the position information obtained from the position measurement device, as described later. Further, when the estimated hardness differs depending on the compression strength, the hardness may change depending on the depth from the surface of the living body.
The display unit 26 also includes a compression instruction unit 261 that instructs the operator how to compress the waveform based on the result of the abnormal waveform detection unit 232. In the compression instruction unit 261, the abnormal waveform detection unit 232
When it is detected that the compression strength is inappropriate, an appropriate compression strength is instructed. Further, when the DC component or the AC component is designated in the hardness estimation unit 234 as shown in FIGS. 8 and 9, an appropriate compression strength is instructed.

The power supply unit 27 is a power supply means in the hardness calculation device 2. The input unit 28 is a means operated by the user for inputting various information, and is realized by, for example, a keyboard or a mouse.

Returning to FIGS. 2 and 3, the main body 14 has a receiving coil 11, a coil board 110 on which the receiving coil 11 is mounted, a battery 16, and an operation button 140 operated at the start of hardness calculation or the like.
, And the operating circuit board 1 connected to the motor 17, the receiving coil 11 and the transmitting coil 12.
It is equipped with 41. The movable portion 15 includes a transmission coil 12 and a coil board 120 on which the transmission coil 12 is mounted. One or more springs 13 are arranged between the coil board 110 and the coil board 120.

According to the measuring device 1, when the motor 17 causes a rotational movement, the shaft attached to the position deviated from the axis of the motor 17 rotates, and the vertically movable portion 18 moves up and down accordingly (crank mechanism). .. When the operation button 140 is pressed, the motor 17 starts rotating, and when the operation button 140 is stopped, the motor 17 stops rotating. By this vertical movement, the movable portion 15 is periodically pressed against the measurement target. When the movable portion 15 is pressed against the object so that the object is recessed, the spring 13 contracts and the transmitting coil 12 and the receiving coil 11 approach each other, and the magnitude of the magnetic field detected by the receiving coil 11 increases. Information on the voltage corresponding to the magnitude of the reaction force generated in the contact portion 20 is output from the receiving coil 11.

As described above, since the motor 17 stops rotating when the operation button 140 is stopped, the stop position of the contact portion 20 differs depending on the timing when the operator releases the operation button 140. Therefore, the rotational position of the motor 17 is measured by a photo sensor, and the contact portion 20 is used.
Is controlled so that it always stops at a fixed position. As a result, the measuring device 1 has the same hardware configuration as the durometer, and the DC component of the waveform becomes the same as the output value of the durometer. The biohardness tester 1000 will include the function of a durometer.

≪Execution order of hardness estimation application≫
The processing of the biohardness tester 1000 will be described with reference to the flowchart of FIG. 11 (see other figures as appropriate). Hereinafter, the human body will be described as an example as a measurement object. First, a subject whose body hardness is measured by an operator is registered (step S1). The contents to be registered are the subject ID,
Subject name, gender, age, disease information, treatment information, measurement results of other testing equipment, etc.
FIG. 12 shows an example of the registration screen.

Next, the hardness of the human body is measured with a hardness tester. Specifically, when the operator turns on the operation button 140 of the measuring device 1, the motor 17 starts to operate and the data of the magnetic sensor starts to be recorded (step S2). Here, the entire measuring device 1 is attached to the motor 17. In the case of this configuration, by driving the motor 17, a predetermined frequency fHz
The movable portion 15 can be continuously pressed against the object. For example, f = 2 to 8 Hz may be set. The microprocessor 23 of the hardness calculation device 2 is a movable portion 1 of the measuring device 1.
Every time 5 is pressed against the object to be measured 150, information from the measuring device 1 is acquired.

With the operation button 140 turned on, the operator gradually presses the measuring device 1 so as to be perpendicular to the surface of the human body (step S3). Here, if the measured magnetic sensor waveform is abnormal, such as when the compression strength is too strong or too weak, or when it is tilted rather than perpendicular to the human body surface, it is detected by the microprocessor 23. (Step S4). This determination is made, for example, by the voltage of the DC component of the magnetic sensor output voltage shown in FIG.
It can be done from the frequency of the AC component. This process is executed by the determination unit 235 of the microprocessor 23. If Yes, the process proceeds to step S5, and if No, the process proceeds to step S6. When it is determined that the waveform is abnormal, the microprocessor 23 displays a message for re-measurement on the display unit 26, prompting the operator to correct the compression method (step S5).

If it is determined in step S4 that the waveform is not abnormal, the hardness is estimated (step S).
6). The microprocessor 23 determines whether or not those values are abnormal values based on the estimated values calculated in step S3 (step S7). This process is performed by microprocessor 2
It is executed by the determination unit 235 of 3. If Yes, the process proceeds to step S5, and if No, the process proceeds to step S8. It should be noted that the determination of whether or not it is an abnormal value can be realized, for example, by comparing the mean value and the variance with a preset threshold value.

If No in step S7, the estimated hardness is stored as a measured value (step S8).
The processes from step S2 to step S8 are repeated at a plurality of measurement points as needed (step S9). When the measurement at all the measurement points is completed, the microprocessor 23 causes the display unit 26 to display information on the hardness and a diagram in which the hardness is mapped on the schematic diagram of the human body (step S10).

FIG. 13 shows an example of this screen. In the example of FIG. 13 (a), the hardness map shows the hardness at nine measurement points of the human body. The magnitude of hardness can be expressed by the difference in shade and color.
Further, as shown in FIG. 13B, the slide bar 1300 is used to display the hardness at different depths. Further, in order to evaluate the therapeutic effect of acupuncture and massage, it is possible to compare with the past hardness and hardness map (step S11).

In this way, the numerical value of the hardness at a certain place can be displayed or compared with the past value. It is also possible to display a hardness map including the hardness of a plurality of measurement points or compare it with a past hardness map. Further, in the measuring method of this embodiment, hardness of different depths can be measured.

To measure the hardness at different depths, for example, in the data of FIG. 6, the AC component FAC1 having a large timing of the DC component and the AC component FAC2 having a small timing of the DC component are acquired, and the corresponding hardness is obtained for each. The AC component FAC1 with a large timing of the DC component reflects the hardness of the deep part, and the AC component FAC2 with a small timing of the DC component reflects the hardness of the shallow part. As described above, since the graph of FIG. 6 is premised on uniform hardness, the size of the AC component is the same at any location. However, when the hardness differs depending on the depth, the size of the AC component differs depending on the size of the DC component.

Further, in the method of directly using the magnetic sensor output as shown in FIGS. 8 and 9, a plurality of depths can be measured by setting a plurality of fixed points.

14A and 14B are table diagrams showing an example of a correspondence table included in the database 1001 of the embodiment.

In FIG. 14A, as shown in FIG. 6, the waveform of the output voltage of the magnetic sensor 19 is converted into the waveform of the pressure.
This is an example of a correspondence table that converts hardness from pressure waveforms. FIG. 14A (a) is a correspondence table between the DC component amplitude and the depth. FIG. 14A (b) is a correspondence table of AC component amplitude and hardness. These tables may be obtained experimentally in advance, for example. When it is desired to measure the hardness at an arbitrary depth, the DC component amplitude corresponding to the depth is obtained from FIG. 14A (a), and the AC component amplitude at the timing of the DC component amplitude is obtained. Then, the hardness corresponding to the amplitude of the AC component is obtained from FIG. 14A (b).

FIG. 14B is an example of a correspondence table in the case where the output voltage of the magnetic sensor is used as it is as a force sensor to estimate the hardness as shown in FIG. In the example of FIG. 8, the AC component V _AC of the voltage when the DC component V _D of the voltage is fixed to a constant value V _DC is used as the estimated hardness. In this case, since the correspondence between the AC component amplitude and the hardness changes depending on the size of the DC component, that is, the depth, a plurality of correspondence tables are required depending on the depth. FIG. 14B (a) is a correspondence table of AC component amplitude and hardness in a shallow part (DC component size is 100 mV), and FIG. 14B (b) is a deep part (DC component size is 200 m).
It is a correspondence table of AC component amplitude and hardness of V).

Further, as shown in FIG. 9, when the hardness is estimated based on the DC component when the AC component is fixed, a correspondence table of the DC component and the hardness is prepared corresponding to a plurality of AC components. .. Here, the hardness in the correspondence table may be an estimated hardness or a value obtained by converting the estimated hardness into a known hardness as described with reference to FIG.

FIG. 15 shows an example of a screen for comparing and displaying past data and the latest data. The hardness information and the hardness map may be displayed side by side, or the difference between the two may be displayed. Above,
All steps are completed.

≪Estimation of measurement position≫
Next, a method of obtaining the measurement position information necessary for displaying the estimated hardness on the map on the display unit 26 will be described. The position measuring device 3 shown in FIG. 1 is composed of, for example, five transmitting coils 302 and a three-axis receiving coil 301.

FIG. 16 is a schematic layout diagram of the five transmitting coils 302 and the three-axis receiving coil 301. Here, the number of transmission coils 302 is set to 5, but any number may be used as long as it is necessary for acquiring the target position information. The 3-axis receiving coil 301 is mounted inside the biohardness meter 1000. Further, it is assumed that the positional relationship between the five transmitting coils 302 and the object to be measured is known. The transmission coil 302 is arranged, for example, on a sample table on which the measurement object 150 is arranged. Object to be measured 150
If it is a human body, it may be built in a bed or the like. This makes it possible to estimate the measurement position of the biohardness meter with respect to the transmitting coil.

The measurement principle of the position measuring device 3 is the same as that of the measuring device 1. When a current is passed through the transmitting coil 302 by the position estimation drive circuit 29, a magnetic field is generated in the surroundings, and the magnetic field causes a voltage in the 3-axis receiving coil 301 by the principle of electromagnetic induction. Unlike the measuring device 1, since there are a plurality of receiving coils and oscillating coils, magnetic field interference becomes a problem. This problem is solved by a method of adopting a time division method that switches between passing and detecting current in each combination of the transmitting coil and the receiving coil (15 ways) in a short time. As another method, when a current is passed through a plurality of transmitting coils at the same time, the magnetic fields of the plurality of transmitting coils can be detected without interfering with each other by changing the frequency of the transmitting coils.

The position estimation unit 236 calculates the position information necessary for displaying the estimated hardness on the surface of the living body as a map on the display unit 26. From the obtained magnetic field data, by simulating the magnetic field
The three-dimensional position (horizontal direction X, Y, vertical direction Z) and attitude angle (elevation angle θ, azimuth angle φ) of the 3-axis receiving coil are estimated. When displaying on the display unit 26, for example, when mapping on a schematic diagram of the back of a human body, the estimated hardness may be displayed in a color map using only the position information in the horizontal directions X and Y. In addition, when the map is displayed three-dimensionally on the face surface, the map may be displayed using the position information of X, Y, and Z.

In this embodiment, magnetic field measurement is used for position estimation, but other methods may be used, for example, the measurement position may be estimated by camera photography. Further, the measurement position may be estimated by integrating the acceleration sensor in the second order.

According to the present embodiment described above, the pressure for outputting the reaction force information corresponding to the reaction force at the contact portion between the main body portion having the movable portion continuously pressed against the measurement object and the movable portion in the measurement object. In a hardness meter including a sensor, a motor, and a crank mechanism driven by the motor to move the main body and the movable part into a piston, the hardness is estimated based on the AC component of the pressure sensor value generated by the piston movement of the movable part. A hardness estimation unit is provided.

In this embodiment, a magnetic sensor is used as the pressure sensor, but other types of sensors may be used. For example, instead of the magnetic sensor 19 in FIG. 2, a piezo resistance type pressure sensor using a semiconductor process can be arranged. The piezo resistance type pressure sensor forms a semiconductor strain gauge on the surface of the diaphragm, and converts the change in electrical resistance due to the piezo resistance effect generated by the deformation of the diaphragm by an external force (pressure) into an electric signal. .. Therefore, the force information shown in FIG. 6 can be obtained directly from the output of this sensor.

The present invention is not limited to the above-mentioned examples, and includes various modifications. The above-mentioned embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the configurations described. It is also possible to replace a part of the configuration of one embodiment with the configuration of another embodiment. It is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, other configurations can be added / deleted / replaced with respect to a part of the configurations of each embodiment.

The various processes of the microprocessor 23 described above may be realized by hardware, for example, by designing a part or all of them with an integrated circuit. Further, each of the above configurations, functions, and the like may be realized by software by the processor interpreting and executing a program that realizes each function. Information such as programs, tables, and files that realize each function can be stored in a memory, a hard disk, a recording device such as an SSD (Solid State Drive), and a recording medium such as an IC card, an SD card, or a DVD.

In the above-mentioned embodiment, the control line and the information line are shown as necessary for explanation.
Not all control lines and information lines are shown on the product. All configurations may be interconnected.

1 ... Measuring device 2 ... Hardness calculation device 11 ... Receiving coil 12 ... Transmitting coil 13 ... Spring 14 ... Main body 15 ... Moving part 16 ... Battery 17 ... Motor 18 ... Vertically movable part 19 ... Magnetic sensor 20 ... Contact part 21 ... Drive Circuit 23 ... Microprocessor 24 ... Storage unit 25 ... Sound generation unit 26 ... Display unit 27 ... Power supply unit 28 ... Input unit 3 ... Position measuring device 31 ... AC oscillation source 32 ... Amplifier 33 ... Preamp 34 ... Detection circuit 35 ... Reference signal 36 ... Low pass filter 37 (a) ... Spring 37 (b) ... Dashpot 110, 120 ... Coil board 140 ... Operation button 141 ... Operation circuit board 130 ... Operation circuit board 140 ... Operation button 231 ... Voltage waveform generator 232 ... Abnormality Waveform detection unit 233 ... Voltage / pressure conversion unit 234 ... Hardness estimation unit 235 ... Judgment unit 236 ... Position estimation unit 261 ... Compression indicator unit 301 ... 3-axis receiving coil 302 ... Transmitting coil 1000 ... Biohardness meter

Claims (15)

A moving part that is continuously pressed against the object to be measured,
A sensor that outputs an output signal that reflects the reaction force at the contact portion of the measurement object with the movable portion, and
A power mechanism that causes the movable part to move with a piston,
Based on the AC component of the output signal generated by the piston movement of the moving part,
A hardness estimation unit that estimates the hardness of the object to be measured, and a hardness estimation unit.
A hardness tester characterized by being equipped with. The hardness estimation unit is
The hardness of the object to be measured is estimated based on the amplitude of the AC component of the output signal.
The hardness tester according to claim 1. The hardness estimation unit is
The hardness tester according to claim 2, wherein the hardness of the object to be measured is estimated based on the amplitude of the AC component when the magnitude of the DC component of the output signal is fixed to a predetermined value. The hardness estimation unit is
The hardness of the object to be measured is estimated based on the magnitude of the DC component when the amplitude of the AC component of the output signal is fixed to a predetermined value.
2. The hardness tester according to claim 2. It is provided with an abnormal waveform detection unit that detects an abnormal waveform on condition that the magnitude of the DC component of the output signal is not within a certain range.
The hardness estimation unit is
The hardness of the object to be measured is estimated based on the AC component of the output signal in the range where the abnormal waveform is not detected by the abnormal waveform detection unit.
2. The hardness tester according to claim 2. It is provided with an abnormal waveform detection unit that detects an abnormal waveform on condition that the upper and lower limits of the AC component of the output signal cannot be detected.
The hardness estimation unit is
The hardness of the object to be measured is estimated based on the AC component of the output signal in the range where the abnormal waveform is not detected by the abnormal waveform detection unit.
2. The hardness tester according to claim 2. A voltage / pressure conversion unit that converts the output voltage of the sensor into pressure information is provided.
2. The hardness tester according to claim 2. A position estimation unit that estimates the measurement position of the hardness tester,
A hardness map display unit that maps and displays the hardness estimated using the measurement position, and
To prepare
The hardness tester according to claim 1. The hardness map display unit is
Presents the difference between the two hardness maps,
The hardness tester according to claim 8. The first step to vibrate the moving parts,
The second step of acquiring a sense signal based on the reaction force from the measurement object when the movable part is brought into contact with the measurement object, and
The third step of acquiring the AC component of the sense signal and
The fourth step of estimating the hardness of the object to be measured based on the amplitude of the AC component, and
A hardness measuring method characterized by comprising. In the first step,
A vibrating member that vibrates the movable portion is used, and the vibrating member is connected to the movable portion via a spring.
In the second step,
The sense signal is detected by receiving a signal transmitted from one coil by the other coil by using the first coil arranged in the movable portion and the second coil arranged in the vibrating member. Obtained based on the magnetic sensor signal
The hardness measuring method according to claim 10, wherein the hardness is measured. Using a computer device including a microprocessor, a storage unit, an input unit, and an output unit,
The microprocessor obtains the waveform of the magnetic sensor signal from the input unit.
The sense signal is obtained by converting to a voltage waveform by voltage / pressure conversion.
The hardness measuring method according to claim 11, wherein the hardness is measured. A correspondence table of the amplitude and hardness of the AC component of the sense signal is prepared as a database in the storage unit.
The microprocessor estimates the hardness based on the correspondence table.
The hardness measuring method according to claim 12, wherein the hardness is measured. Using a computer device including a microprocessor, a storage unit, an input unit, and an output unit,
The microprocessor uses the waveform of the magnetic sensor signal as it is as the sense signal.
The hardness measuring method according to claim 11, wherein the hardness is measured. A correspondence table of the amplitude and hardness of the sense signal is prepared as a database in the storage unit.
The correspondence table is
It indicates the correspondence between the amplitude and hardness of the AC component of the sense signal when the DC component of the sense signal is fixed, or
It shows the correspondence between the amplitude and hardness of the DC component of the sense signal when the AC component of the sense signal is fixed.
The microprocessor estimates the hardness based on the correspondence table.
The hardness measuring method according to claim 14, wherein the hardness is measured.

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