JP6730145B2 - Mechanical property measuring system and mechanical property measuring method - Google Patents

Description

The present invention relates to a holder used for measuring the mechanical response characteristics of an object to be measured.

A technique is known in which the deformation behavior of the skin is measured using a dynamic viscoelasticity measuring device, and the relationship between the storage elastic modulus G′ and the loss elastic modulus G″ and the muscle tension state is investigated. Describes that a forearm of a subject is placed on a measurement stage below a rheometer, a probe is brought into contact with the inside of the forearm to cause shear deformation, and a viscoelastic characteristic value is obtained. By conducting such measurements, we are studying the relationship between strain distribution around pressure ulcers and the formation of wounds.However, when the measurement method described in the same document is adopted, the forearm that is the object of measurement is reliably measured. If not fixed, the forearm will unintentionally move during the measurement, and it is not easy to perform highly accurate measurement.

As a fixture for fixing an object to be measured during measurement, Patent Document 1 discloses a fixture including a fixture main body at least a part of which is formed like a net, Has been proposed which is made of a shape memory resin. According to this fixing tool, it is described that the fixing tool main body made of a shape memory resin is heated to be softened and brought into close contact with the object to be measured in this state, whereby the close contact is easily performed.

Further, Patent Document 2 describes a measurement target holder in which a measurement target is accommodated in a hollow portion formed in an inner surface shape along the outer shape of the measurement target.

JP-A-4-343845 JP, 2010-197381, A

"Experimental Mechanics", March 2011, Vol. 11, No. 1, pp. 30-34

However, when the fixtures and holders described in Patent Documents 1 and 2 are used, the state of the measurement target site may change due to the holding and fixing. Further, when the fixtures and holders described in Patent Documents 1 and 2 are used, although the object to be measured can be fixed, it is considered that the object to be measured is reliably arranged at a predetermined position of the measuring device. Absent.

Therefore, an object of the present invention is to provide a holder for an object to be measured which can eliminate the above-mentioned drawbacks of the conventional technique.

The present invention uses a mechanical characteristic measuring device provided with a device main body for measuring a mechanical response characteristic when a measured object is deformed, and a mechanical response characteristic of the measured object is held in a state of being held. A holder for an object to be measured used for measuring below, wherein the holder is deformable into a shape capable of holding the object to be measured according to the outer shape of the object to be measured, It is intended to provide a holder for an object to be measured, the shape of which can be held during measurement.

The present invention also provides a mechanical characteristic measuring system including a mechanical characteristic measuring device including a device body for measuring a mechanical response characteristic when a measured object is deformed, and the holder.

ADVANTAGE OF THE INVENTION According to this invention, the to-be-measured object can be easily fixed and the to-be-measured object of the fixed state can be reliably arrange|positioned at the fixed position in the measuring device.

FIG. 1 is a schematic view showing a mechanical characteristic measuring device used with a holder for an object to be measured of the present invention. FIG. 2 is a perspective view showing an embodiment of the holder for the object to be measured of the present invention. FIG. 3 is a perspective view showing a state of measuring an object to be measured using the holder for the object to be measured of the present invention. FIG. 4 is a perspective view showing a state in which the object to be measured is measured using the holder for the object to be measured of the present invention. FIG. 5 is a perspective view showing a state in which a human being who is a subject is omitted from the state shown in FIG. FIG. 6 is a perspective view of a state in which the holder for the object to be measured of the present invention is deformed to the outer shape of the object to be measured and is placed on the mounting surface of the pedestal to fix the shape, as seen from the upper surface side. Is. FIG. 7 is a perspective view of a state in which the holder for the object to be measured of the present invention is deformed to the outer shape of the object to be measured and is placed on the mounting surface of the pedestal to fix the shape, as seen from the lower surface side. Is. FIG. 8 is a perspective view showing an example of a probe used for measuring the mechanical response characteristic of the measured object using the holder for the measured object of the present invention. FIGS. 9A and 9B are graphs showing the results of the skin dynamic response characteristics (torque and tan δ) measured in Example 1 for the human inner upper arm. FIG. 10 is a graph showing the results of skin dynamic response characteristics (torque) measured in Example 2.

The present invention will be described below based on its preferred embodiments with reference to the drawings. The holder for an object to be measured (hereinafter, also simply referred to as “holder”) of the present invention uses a mechanical characteristic measuring system including an apparatus body for measuring a mechanical response characteristic when a deformation is applied to the object to be measured. It is used when measuring. There is no particular limitation on the type of the object to be measured, it is possible to give a deformation, and as long as it has a property capable of measuring the mechanical response characteristics, for example, liquid, gel, paste, and solid May be The object to be measured may be a living body or a non-living body. When the living body is the object to be measured, examples of the living body include humans and non-human living organisms. When a human being is the object to be measured, the measurement is performed for non-medical purposes. The skin is typically mentioned as the measurement site with which the probe comes into contact, but the measurement site is not limited to this, and may be another site, such as a mucous membrane.

Examples of types of deformation applied to the object to be measured include, but are not limited to, compression, tension, twisting, and bending. Typical examples of the dynamic response parameter when the object to be measured is deformed include elastic modulus, viscosity, tack force, friction coefficient, normal force, and torque. Specific examples include dynamic viscoelasticity.

FIG. 1 shows a dynamic viscoelasticity measuring apparatus 10 as an example of a mechanical characteristic measuring apparatus used with the holder of the present invention. The dynamic viscoelasticity measuring device 10 includes a device body 11, and a probe 12 is attached to the device body 11. The probe 12 has various shapes according to the type of deformation given to the object to be measured. The probe 12 is attached so as to hang vertically downward from the apparatus main body 11. However, the mounting mode of the probe 12 is not limited to this, and may be mounted so as to project in the horizontal direction from the apparatus main body 11, for example. The mounting mode of the probe 12 is appropriately determined according to the type of deformation given to the measured object, the shape of the probe 12, the type of the measured object, the shape of the measured object, and the like.

The dynamic viscoelasticity measuring device 10 is mounted on the mounting surface 13 a of the table 13. A pedestal 14 is installed at a position adjacent to the dynamic viscoelasticity measuring device 10. An object to be measured (not shown) is placed on the gantry 14. Therefore, the mounting surface 14 a of the gantry 14 is located at least immediately below the probe 12.

FIG. 2 shows a holder 20 used together with the dynamic viscoelasticity measuring device 10 shown in FIG. The holder 20 can be deformed into a shape capable of holding the measured object according to the outer shape of the measured object. Along with this, the holder 20 can hold the shape at the time of measurement. In order to achieve such a configuration, the holder 20 includes a deformable airtight bag 21. The airtight bag 21 is made of a gas-impermeable sheet material. The airtight bag 21 is preferably made of a flexible material such as a polymer material or a foamed polymer sheet for the purpose of improving the touch of the holder 20. Further, the airtight bag 21 may have its outer surface covered with a cloth. Covering with a cloth is particularly useful when the device under test is part of the human body. A granular substance (not shown) is enclosed in the airtight bag 21. Generally, the average size of the granular substance is 1 mm or more from the viewpoint of maintaining a certain degree of flexibility when the pressure inside the airtight bag 21 is reduced, and the conformability to the outer shape of the object to be measured is maintained. From the viewpoint of the above, it is composed of a granular body of 8 mm or less. The granular body is composed of a solid substance having a rigidity that does not substantially deform with respect to the load applied when the object to be measured is measured. Further, this granular body is a solid body or a hollow body. You may use the mixture of a solid body and a hollow body.

The shape of the granular substance is not particularly limited, and may be, for example, spherical, polyhedral, ellipsoidal, fusiform, or amorphous. A combination of these shapes may be used. From the viewpoint of enhancing the filling property of the granular material inside the airtight bag 21 and reliably maintaining the shape of the holder 20 when measuring the object to be measured, it is preferable to use the granular material having a substantially spherical shape. ..

The granular substance is enclosed in the airtight bag 21 in a fluid state. Thereby, the holder 20 can freely change its outer shape. In addition, the holder 20 preferably has a flat body as shown in FIG. 2 because the holder 20 can be easily deformed into a shape according to the outer shape of the object to be measured.

The airtight bag 21 of the holder 20 is provided with a communication part 22. The communication portion 22 is a member that connects the inside and the outside of the airtight bag 21. In the embodiment shown in FIG. 2, the communication part 22 has a tubular shape. A two-way valve (not shown) is provided in this cylinder, for example. The two-way valve has a structure capable of adjusting the exhaustion of gas from the inside of the airtight bag 21 to the outside and the inflow of gas from the outside to the inside through the communication portion 22. A check valve can be used instead of the two-way valve.

The holder 20 having the above-described structure is an article that is widely known as a so-called decompression type bead mat. When using this type of holder 20, the exhaust pipe 41 of the exhaust pump 40 prepared separately from the holder 20 is connected to the communication portion 22 attached to the airtight bag 21. At this point, air is present in the airtight bag 21. Further, the granular substance enclosed in the airtight bag 21 is kept in a fluid state, and the holder 20 is also kept in a deformable state by an external force. When the exhaust pump 40 is operated from this state, the air existing in the airtight bag 21 is gradually exhausted and the airtight bag 21 gradually shrinks, and the granular material gradually loses fluidity and tightens. It becomes a solid state. When the inside of the airtight bag 21 is decompressed with a suction force of about -20 to -40 kPa (gauge pressure), the granular material loses its fluidity and becomes a substantially undeformable compacted state. In this way, the holder 20 can hold its shape.

FIG. 3 shows an example of a state in which an object to be measured is measured using the dynamic viscoelastic device 10 and the holder 20. In the figure, a state is shown in which the human 30 is the subject and the skin inside the forearm portion 31 of the human 30 is the object to be measured. In the embodiment shown in FIG. 3, measurement is carried out for non-medical purposes such as beauty purposes, the purpose of developing or selecting cosmetics to be applied to the skin, and the purpose of developing or selecting quasi-drugs to be applied to the skin. It is carried out.

In FIG. 3, a human subject 30, who is a subject, sits down on a chair 15 adjacent to the gantry 14, and the forearm portion 31 of the left arm is placed on the placing surface 14 a of the gantry 14 so that the inside thereof faces the probe 12. The state is shown. The holder 20 is arranged between the forearm 31 and the mounting surface 14a. The holder 20 is a vertically long flat body, and is arranged between the forearm 31 and the mounting surface 14a such that its longitudinal direction coincides with the extending direction of the forearm 31.

In this case, the holder 20 is arranged such that both end regions 23a and 23b of the holder 20 extend outward from the front and rear edges of the mounting surface 14a of the gantry 14 and hang downward vertically. Adjust the position to be used. Next, the holder 20 in the state shown in FIG. 3 and the forearm portion 31 are made to fit well, and the holder 20 is deformed so that they are in close contact with each other and a gap is not generated between them. Under this state, the exhaust pump 40 shown in FIG. 2 is connected to the communicating portion (not shown) of the holder 20 to degas the gas in the airtight bag 21 of the holder 20. Due to this deaeration, the airtight bag 21 of the holder 20 gradually shrinks, and the granular material loses its fluidity and becomes a substantially undeformable compacted state. As a result, the fixed state of the forearm 31, which is the object to be measured, is completed. As a result, movement of the forearm 31 is blocked during the measurement. Further, in this state, the human 30 is in a natural posture, so that the physical load is small. Further, since excessive tightening does not occur when the forearm portion 31 is fixed by the holder 20, physical changes that may affect measurement, such as changes in blood flow and muscle relaxation, are less likely to occur.

When the fixed state of the forearm portion 31 is completed in this way, as shown in FIG. 4, the probe 12 attached to the device body 11 of the dynamic viscoelasticity measuring device 10 is lowered to contact the skin of the forearm portion 31. Contact. Then, the probe 12 is caused to perform a predetermined operation. Examples of the predetermined operation in the present embodiment include, but are not limited to, compression, pulling, twisting, and the like. By the operation of the probe 12, the skin of the forearm portion 31 is deformed, and the mechanical response characteristic caused by the deformation is detected and measured by the probe 12. During the measurement, the forearm portion 31 is securely fixed by the holder 20. Therefore, highly accurate measurement can be performed. Further, at this time, by grasping a predetermined place which is the other hand, the posture of the body can be kept constant and more accurate measurement can be performed.

FIG. 5 shows a state after the measurement shown in FIG. 4 has been performed. The human subject 30 is not shown in FIG. As shown in FIG. 5, the holder 20 that has been degassed and has its shape fixed has its front-rear position fixed on the mounting surface 14 a of the gantry 14. The reason for this is that, as shown in FIGS. 6 and 7, in the holder 20 in a fixed shape, the shape is fixed in a state in which both end regions 23a and 23b of the holder 20 hang vertically downward. This is because the both end areas 23a and 23b function as the positioning means in the front-rear direction. Specifically, one 23a of both end regions of the holder 20 is locked to the front end of the mounting surface 14a of the gantry 14, and the other 23b of both end regions is locked to the rear end of the mounting surface 14a. Then, the holder 20 is fixed at a fixed position in the front-rear direction. As a result, for example, when the measurement is once completed and the human 30 leaves the dynamic viscoelasticity measuring apparatus 10, that is, after the state shown in FIG. If the forearm portion 31 is fitted into the recess 20a of the tool 20, the previously measured state can be easily reproduced and remeasurement can be easily performed. In this case, there is a possibility that a positional deviation occurs in the horizontal direction during the re-measurement, but even if that is the case, the lateral positional deviation can be easily corrected by translating the holder 20 in the horizontal direction. can do. Therefore, the displacement in the lateral direction does not affect the accuracy of the remeasurement. Alternatively, a convex portion or the like may be provided on the gantry 14 or the mounting surface 14a so that it can be fixed laterally.

The dynamic viscoelasticity measuring apparatus 10 used in the above-described embodiment is for applying a controlled deformation (or a controlled force) to human skin and detecting a force (or a deformation) as a response thereto. It is preferable to have a mechanism. Specifically, it is preferable to use any one of the following devices (1) to (3).
(1) Mechanical measurement is performed by applying rotational vibration deformation or rotational deformation in a direction parallel to the contact surface while applying a pressing force or a pressing displacement in a direction perpendicular to the contact surface to the center point of the skin measurement surface site. Possible equipment.
(2) Mechanical measurement can be performed by pressing with a constant force or deformation in a direction perpendicular to the tangential surface to the center point of the skin measurement surface part, or by pressing or pulling up with a controlled pressing force or moving speed. apparatus.
(3) A device that can perform measurement in which both modes (1) and (2) are combined.

In particular, in order to perform highly accurate measurement, it is preferable to use a device having the following performance.
・Detectable minimum torque (vibration): 1 nNm or more and 1 μNm or less ・Minimum detectable torque (rotation): 5 nNm or more and 1 μNm or less ・Maximum measurable torque: 10 mNm or more and 300 mNm or less ・Torque resolution: 0.07 nNm or more and 100 nNm or less ・Settable angle: 0.07 μrad or more-Rotation angle resolution: 7 nrad or more and 70 nrad or less-Step speed (response time): 3 ms or more and 30 ms or less-Step distortion (response time): 8 ms or more and 50 ms or less-Step time (99% of the set value) ): 10 ms or 200ms or less-speed ^range: 10 ^-4 s ^{-1 ~314s} -1 or level angular frequency ^range: 10 ^-3 s ^{-1 ~628s} -1 or level normal force range: 0.005 N or 50N or less- Normal force resolution: 0.5mN

The measurement using the holder 20 of the present invention is useful in various situations. For example, when the subject is a human, it is possible to objectively evaluate the performance such as the skin feel obtained by the cosmetic preparation by applying or applying the cosmetic preparation to the human skin and measuring under the condition. it can. This evaluation is useful for selecting a cosmetic preparation suitable for each individual, and also useful for developing a new cosmetic preparation. In this case, by appropriately selecting the type of the probe 12 attached to the device 10, it is possible to further improve the measurement accuracy, and thus the evaluation accuracy. For example, when performing viscoelasticity measurement using the probe 12, by using the probe 12 in which a plurality of grooves 25 are provided on the contact surface with the object to be measured as shown in FIG. It is possible to effectively prevent the occurrence of slippage between the two and to improve the accuracy of measurement. Further, when performing friction measurement or compression measurement, the accuracy of measurement can be improved by using the probe 12 made of a material whose contact surface with the object to be measured is smooth and which has high wear resistance. ..

Conventionally, for example, a cute meter or a derma torque meter has been used as an instrument for measuring the rheological properties of human skin and a coating film of a cosmetic preparation applied on the skin. Further, as a device for measuring the frictional characteristics of human skin and a coating film of a cosmetic preparation applied on the skin, for example, a KES-SE friction tester or Handy Lab Master has been used. However, these devices have the drawbacks that measurement is difficult under the condition that the cosmetic preparation is applied and that pressing cannot be controlled. On the other hand, if the holder 20 is used, the rheological properties of the human skin and the coating film of the cosmetic preparation applied on the skin can be easily measured. Moreover, the holder 20 has a simple structure, and the work of fixing the shape can be easily performed. In addition, it can be used repeatedly multiple times. As described above, the measurement using the above-described holder becomes easier and more accurate than ever before, and is extremely useful in various measurement fields.

Although the present invention has been described above based on its preferred embodiments, the present invention is not limited to the above embodiments. For example, in the above-described embodiment, the holder and the mechanical characteristic measuring system of the present invention have been described by taking the viscoelasticity measuring apparatus as an example of the mechanical characteristic measuring apparatus, but the mechanical characteristic measuring apparatus is not limited to this.

Further, in the above-described embodiment, the present invention has been described by taking the so-called decompression type bead mat as an example of the holding device 20, but a holding device other than the decompression type bead mat may be used.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the scope of the invention is not limited to such embodiments.

[Example 1]
In the present example, the mechanical response characteristics of the skin were measured using the inner part of the upper arm of a human as the object to be measured. For the measurement, the dynamic viscoelasticity measuring device 10 shown in FIG. 1 and the holder 20 shown in FIG. 2 were used. A decompression type bead mat was used as the holder 20. The holder 20 was installed on the apparatus 10 as shown in FIG. 3, and the inside of the upper arm of the human was held by the holder 20. As the probe 12 attached to the dynamic viscoelasticity measuring device 10, a disk cell made of an aluminum alloy having a diameter of 8 mm, which was subjected to an anti-slip treatment by forming a groove, as shown in FIG. The torque value obtained by this measurement is an index of the hardness of human skin, and the tan δ value is an index of the quality of the skin (elastic or viscous). The measurement was performed in two steps. First, the cell was controlled so as to press the measurement target portion with a pressing force of 1N (total 5 seconds), and subsequently, the pressing force was controlled to 1N, and 10 points of measurement were performed at regular time intervals. The measurement frequency was 2 Hz and the amplitude was 0.8 degrees.

The blank skin to which cosmetics or the like was not applied was measured with or without holding by the holder 20. The results are shown in FIGS. 9(a) and 9(b). Since it was found that the results did not change significantly even if the measurement time interval was changed slightly, the measurement time interval was shortened from a certain time point compared to the early stage of the study. In the figure, the results without holding by the holding tool 20 are the measurement results at 5 second intervals, and the results with holding by the holding tool 20 are the measurement results at 3 second intervals. Both the torque and the tan delta show the results of two measurements, but it can be seen that both the torque value and the tan δ value change less when the holding tool 20 holds them.

In order to quantitatively show the fluctuation of the measured values, the standard deviation of the measured values in each measurement was determined, and the results shown in Table 1 below were obtained.

As is clear from the results shown in the table, it can be seen that the holding accuracy of the torque 20 and the tan δ value by the holder 20 improves the accuracy of measurement by one digit as compared with the case where the holding is not performed.

[Example 2]
The example which measured the change of the hardness of the skin resulting from application of commercial lotion A, B, and C by the method of this invention is shown. The dynamic viscoelasticity of the blank skin before applying the lotion and the skin immediately after applying each lotion and after a lapse of a certain time after application were measured. In order to know the time change of the hardness of the skin caused by the application of the lotion, the change rate based on the torque value at the time of measuring the blank skin was obtained at each measurement point. The rate of change is defined by the following formula.
Rate of change=(T _t −T ₀ )/T ₀
In the formula, T ₀ represents the torque value of blank skin, and T _t represents the torque value after t minutes have elapsed after applying each lotion.
FIG. 10 shows the dependency of the change rate on the elapsed time. As is clear from the results shown in the figure, it was possible to measure that the application of the lotion reduced the hardness of the skin with any lotion immediately after the application, but the behavior thereafter was completely different depending on the lotion.

10 Dynamic Viscoelasticity Measuring Device 11 Device Main Body 12 Probe 13 Table 14 Stand 14a Mounting Surface 20 Holding Tool 20a Recess 21 Airtight Bag 22 Communication Portion 30 Human 31 Forearm

Claims (4)

Mechanical property measurement apparatus including a device body for measuring a mechanical response characteristic when a measured object is deformed and a holder for holding the measured object when measuring the mechanical response characteristic A system,
The mechanical characteristic measuring device includes a gantry, the holder is arranged on a mounting surface of the gantry,
The holder is arranged such that both end regions thereof extend outward from the front and rear end edges of the mounting surface of the gantry and hang vertically downward.
The holder can be deformed into a shape capable of holding the object to be measured according to the outer shape of the object to be measured, and can hold the shape and the shape in which the both end regions hang down during measurement. A dynamic characteristic measurement system that has been developed. Communicating said retainer, which connects an airtight bag deformable into a shape capable of holding the object to be measured, and the granular material enclosed in the interior of the airtight bag, and its inside and outside provided to the airtight bag The mechanical characteristic measuring system according to claim 1, further comprising a section and a valve provided in the communication section. The mechanical characteristic measuring system according to claim 2, wherein an outer surface of the airtight bag is covered with a cloth. Mechanical property measurement apparatus including a device body for measuring a mechanical response characteristic when a measured object is deformed and a holder for holding the measured object when measuring the mechanical response characteristic A method for measuring mechanical characteristics for non-medical purposes using a system,
The mechanical characteristic measuring device includes a gantry,
The holder is capable of being deformed into a shape capable of holding the measured object according to the outer shape of the measured object,
The holder is arranged such that both end regions thereof extend outward from the front and rear end edges of the mounting surface of the gantry and hang downward vertically.
A mechanical characteristic measuring method for measuring the mechanical response characteristic by holding the holder in a shape matching the outer shape of the object to be measured and fixing the holder in a state where the both end regions of the holder are hanging .

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