Measuring apparatus

Abstract

To simply measure the distortion of temporomandibular joints.SOLUTION: A measuring apparatus 30 comprises: sensors 1A and 1B for detecting the distortions of the face at the positions of the right and left temporomandibular joints of a user, as resistance values; and a right / left difference identification unit 22 which identifies the presence or absence of the distortions of the temporomandibular joints of the user on the basis of the resistance values output by the sensors 1A and 1B. The sensors 1A and 1B to be worn at the positions of the temporomandibular joints on the right side and the left side of the face are respectively one or more.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a measuring device.

Background Art

[0002] In order to prevent or improve diseases such as temporomandibular joint disorders, techniques for measuring whether the movement of the temporomandibular joint is normal have been developed. For example, in Patent Document 1, displacement sensors inserted into the external ear are used to detect displacements corresponding to the movements of the temporomandibular joint caused by mandibular movement.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technique of Patent Document 1, it is necessary to insert a displacement detection sensor into the external auditory canal. Therefore, it is necessary to design a sensor holding part that conforms to the shape of the ear hole, and there is a problem in that other people can use the same device from a hygienic point of view.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a measuring device capable of easily measuring the distortion of the temporomandibular joint.

Means for Solving the Problems

[0006] In order to solve the above problems, a measuring device according to an aspect of the present disclosure includes a sensor unit that detects distortion of the face at the positions of the left and right temporomandibular joints of a user as a resistance value, and based on the resistance value output by the sensor unit, a left-right difference specifying unit that specifies the presence or absence of distortion of the temporomandibular joint of the user, and the sensor unit is mounted at one or more positions on the positions of the temporomandibular joints on the left and right side faces of the face, respectively.

Effects of the Invention

[0007] According to this disclosure, temporomandibular joint misalignment can be easily measured. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows an overview of the measuring device according to Embodiment 1. [Figure 2] This is a block diagram showing the main components of the aforementioned measuring device. [Figure 3] This diagram schematically illustrates the opening and closing movements of the user's jaw and the stretching and contracting of the skin around the temporomandibular joint. [Figure 4] This is a plan view illustrating a strain gauge according to Embodiment 1. [Figure 5] This is a cross-sectional view illustrating the strain gauge mentioned above. [Figure 6] This is a cross-sectional view showing another example of the strain gauge mentioned above. [Figure 7] This figure shows an overview of the measuring device according to Embodiment 2. [Figure 8] This is a perspective view showing the pressure detection surface side of the strain sensor according to Embodiment 3 in its standalone state. [Figure 9] Figure 8 is a front view of the pressure detection side of the strain sensor. [Figure 10] These are a plan view and a cross-sectional view showing an example of a detection element included in a strain gauge according to Embodiment 4. [Figure 11] These are perspective views, plan views, and cross-sectional views showing an example of a detection element included in a strain gauge according to Embodiment 5. [Figure 12] These are perspective views, plan views, and cross-sectional views showing another example of a detection element included in a strain gauge according to Embodiment 5. [Figure 13] These are perspective views, plan views, and cross-sectional views showing yet another example of a detection element included in a strain gauge according to Embodiment 5.

[0009] The embodiments for carrying out the invention will be described below with reference to the drawings. In each drawing, the same reference numeral is used for identical components, and redundant explanations may be omitted. In the following drawings, the terms "right" and "left" refer to left and right on the drawing.

[0010] [Embodiment 1] Figure 1 is a diagram showing an overview of the measuring device 3 according to this embodiment. The measuring device 3 includes strain sensors 1A and 1B and an information processing device 2. Strain sensor 1A is attached to the left side of the user of the measuring device 3 (hereinafter also simply referred to as "user") at the temporomandibular joint. Strain sensor 1B is attached to the right side of the user at the temporomandibular joint.

[0011] The method of attaching the strain sensors 1A and 1B is not particularly limited. For example, the strain sensors 1A and 1B may be attached to the user's skin by adhering them to a support having an adhesive layer, such as the adhesive part of a patch or bandage, so that they are positioned at the temporomandibular joints on the left and right sides of the user's face, respectively. Alternatively, the strain sensors 1A and 1B may be fixed to a support such as a band or belt that covers the side of the user's face, including at least the portion of the mandibular and temporomandibular joints. In this case, the aforementioned band or belt is wrapped around the side of the user's face and secured so that the strain sensors 1A and 1B are fixed precisely at the temporomandibular joints on the left and right sides of the user's face, respectively.

[0012] Strain sensors 1A and 1B each function as sensors that detect facial distortion at the left and right temporomandibular joint positions of the user as resistance values. Specifically, strain sensor 1A detects facial distortion at the left temporomandibular joint position as resistance values. Strain sensor 1B detects facial distortion at the right temporomandibular joint position as resistance values. The types of strain sensors 1A and 1B are not limited, but strain sensors using resistive strain gauges, particularly Cr-based high-sensitivity strain gauges, can be suitably used.

[0013] Strain sensors 1A and 1B each transmit a resistance value to an information processing device 2. The information processing device 2 identifies the degree of strain of the left and right temporomandibular joints based on the resistance values received from the strain sensors 1A and 1B. In FIG. 1, a personal computer (PC) is shown as an example of the information processing device 2, but the type of the information processing device 2 is not particularly limited. For example, the information processing device 2 may be a wristwatch-type wearable device, a smartphone, or a tablet PC.

[0014] FIG. 2 is a block diagram showing the main configuration of the measuring device 3. Since the main configuration of the strain sensor 1B is the same as that of the strain sensor 1A, the description thereof is omitted in FIG. 2.

[0015] The strain sensor 1A includes strain gauges 12a, 12b, 12c, and 12d, an analog front end (AFE) 13, a signal processing unit 14, a battery 15, and a communication unit 16.

[0016] The strain gauges 12a, 12b, 12c, and 12d each detect the strain at the attachment position of the strain sensor 1A as a resistance value. The detailed structure of the strain gauges 12a, 12b, 12c, and 12d will be described later.

[0017] The analog front end (AFE) 13 includes, for example, a bridge circuit, an amplifier, an analog / digital conversion circuit (A / D conversion circuit), etc. The AFE 13 may include a temperature compensation circuit. The terminal portion of the strain gauge 12a is connected to the bridge circuit of the AFE 13. The bridge circuit outputs a voltage (analog signal) corresponding to the resistance value of the resistor of the strain gauge 12a. The voltage output from the bridge circuit is amplified by an amplifier and then converted into a digital signal by the A / D conversion circuit and sent to the signal processing unit 14. When the AFE 13 includes a temperature compensation circuit, a temperature-compensated digital signal is sent to the signal processing unit 14.

[0018] In the AFE13, for example, the electrodes 125 and 126 (see Figure 4), which are the terminals of all strain gauges 12a, 12b, 12c, and 12d, are connected to the bridge circuit, forming a full bridge. This allows the bridge circuit to output voltages (analog signals) corresponding to the changes in the resistance values ​​of each of the four strain gauges 12a, 12b, 12c, and 12d.

[0019] When the resistance values ​​of multiple strain gauges 12a, 12b, 12c, and 12d configured in this way change, it is possible to detect that the relative positions of the strain gauges 12a, 12b, 12c, and 12d have changed. In this embodiment, an example is shown in which each strain sensor has four strain gauges. However, the number of strain gauges that each strain sensor has is not particularly limited, as long as there is one or more. When a strain sensor has one strain gauge, "resistance value of the strain sensor" is approximately synonymous with "resistance value of the strain gauge". When there is one strain gauge as a means of detecting left and right strain, that one strain gauge acts as the sensor unit.

[0020] Furthermore, in the strain sensor 1A, at least some of the strain gauges 12a to 12d, the AFE 13, the signal processing unit 14, the battery 15, and the communication unit 16 do not necessarily have to be located within the strain sensor 1A. For example, the user may wear only the strain generating body to which each strain gauge is attached, and the AFE 13, the signal processing unit 14, the battery 15, and the communication unit 16 may be built into an external device connected to each strain gauge by a cable or the like. Alternatively, one strain gauge itself may be directly attached to the user, and that strain gauge may be connected to the AFE 13, the signal processing unit 14, the battery 15, and the communication unit 16. In this way, when the strain gauge and the AFE 13, signal processing unit 14, battery 15, and communication unit 16 are configured as separate components, the AFE 13, the signal processing unit 14, the battery 15, and the communication unit 16 may be common components for each strain gauge. In this case, the output values ​​of each strain gauge may be sent to the information processing device 2 via the communication unit 16, and the AFE 13 and signal processing unit 14 may be provided on the information processing device 2 side.

[0021] The signal processing unit 14 outputs the digital signal sent from the AFE 13 to the information processing unit 2 via the communication unit 16. The signal processing unit 14 can be configured to include, for example, a microprocessor, CPU (Central Processing Unit), FPGA (Field Programmable Gate Array), ASIC (Application Specific Integrated Circuit), and other arithmetic units, as well as ROM (Read Only Memory), RAM (Random Access Memory), main memory, etc. The signal processing unit 14 is programmed to, for example, instruct the information processing unit 2 to acquire resistance values ​​from the strain gauges 12a, 12b, 12c, and 12d, or to acquire and transmit the resistance values ​​output from the strain gauges 12a, 12b, 12c, and 12d via the AFE 13. Various functions of the signal processing unit 14 can be realized by reading a program recorded in ROM, etc., into main memory and executing it by the CPU. However, some or all of the signal processing unit 14 may be realized by hardware alone. Furthermore, the signal processing unit 14 may be physically composed of multiple devices or the like.

[0022] Battery 15 is a power source that supplies power to each part of the strain sensor 1A. Alternatively, the strain sensor 1A may receive power from an external power source instead of having battery 15. The communication unit 16 handles communication between the strain sensor 1A and the information processing unit 2. Specifically, the communication unit 16 transmits the resistance value output by the strain gauge 12a to the information processing unit 2. Furthermore, when the strain sensor 1A operates based on instructions from the information processing unit 2, the communication unit 16 receives control instructions for the strain sensor 1A from the information processing unit 2.

[0023] The communication method of the communication unit 16 is not particularly limited. For example, the communication unit 16 may use a wireless or wired LAN communication method such as Wi-Fi®, Bluetooth®, or ZigBee®.

[0024] The information processing device 2 includes at least a communication unit 21 and a control unit 22. The information processing device 2 may also include a storage unit 23 and / or a display unit 24.

[0025] The communication unit 21 acquires resistance value data transmitted from the communication units 16 of strain sensors 1A and 1B. The resistance value data may be the resistance value itself, a value indicating the amount of change in the resistance value (resistance change amount, described later), or may include both. Furthermore, when the information processing device 2 issues instructions to strain sensors 1A and 1B for operation such as operation / stop, the communication unit 21 transmits control instructions to strain sensors 1A and 1B.

[0026] The display unit 24 displays characters, images, etc., related to the processing content and / or processing results of the control unit 22. The manner of display is not particularly limited. The information processing device 2 may also include an audio output unit together with the display unit 24, or in place of the display unit 24. The audio output unit may output audio related to the processing content and / or processing results of the control unit 22.

[0027] The memory unit 23 stores information necessary for the operation of the information processing device 2. For example, the memory unit 23 stores threshold data and correlation data. The memory unit 23 may also store threshold values ​​used by the control unit 22 to determine whether or not there is distortion in the temporomandibular joint. The memory unit 23 may also store index data, which is data that links the difference in resistance values ​​of strain sensors 1A and 1B with an index of the magnitude of temporomandibular joint distortion corresponding to that difference. The criteria for the "index" here are not particularly limited. For example, the degree of distortion may be indicated in three stages: "large," "medium," and "small," or in five stages: levels 1 to 5.

[0028] The control unit 22 comprehensively controls the information processing device 2. The control unit 22 can be implemented as, for example, a microprocessor, a CPU (Central Processing Unit), an FPGA (Field Programmable Gate Array), or an ASIC (Application Specific Integrated Circuit). The control unit 22 may also have memory. The various functions of the control unit 22 can be implemented by reading a program recorded in ROM or the like into main memory and executing it on the CPU. However, some or all of the control unit 22 may be implemented solely by hardware. Furthermore, the control unit 22 may be physically composed of multiple devices.

[0029] The control unit 22 receives resistance values ​​from strain sensors 1A and 1B via the communication unit 21. Based on the resistance values ​​received from strain sensors 1A and 1B, the control unit 22 functions as a left-right difference identification unit, determining the degree of distortion of the user's left and right temporomandibular joints. For example, the control unit determines the degree of distortion of the user's left and right temporomandibular joints using the following processing procedure.

[0030] First, the control unit 22 compares the resistance value of strain sensor 1A with the resistance value of strain sensor 1B to determine which resistance value is higher. Next, the control unit 22 subtracts the smaller resistance value from the larger resistance value. This calculates the difference between the resistance value of strain sensor 1A and the resistance value of strain sensor 1B. Next, the control unit 22 determines whether the calculated difference value is greater than or equal to a threshold value stored in the memory unit 23. If the difference is greater than or equal to the threshold value, the control unit 22 determines that there is a distortion in the user's temporomandibular joint. The control unit 22 may display the determination result on the display unit 24.

[0031] If index data is stored in the memory unit 23, the control unit 22 refers to the index data and identifies the index corresponding to the calculated difference value. In this case as well, the control unit 22 may display the determination result on the display unit 24.

[0032] Figure 3 schematically illustrates the opening and closing movements of the user's jaw and the stretching and contracting of the skin around the temporomandibular joint. More specifically, Figure 3(a) shows the user with their mouth closed (i.e., their mouth closed and not clenched), while Figures 3(b) and (c) show the user with their mouth open. The arrows in Figures 3(b) and (c) indicate the direction and magnitude of the stretching of the facial skin.

[0033] As shown in Figure 3(a), when the user closes their mouth, there is little to no stretching of the facial skin. The control unit 22 may acquire the resistance values ​​of the strain sensors 1A and 1B when the mouth is closed and store these values ​​in the storage unit 23 as the resistance values ​​when the mouth is closed.

[0034] When a user opens and closes their jaw, if there is no misalignment of the temporomandibular joint, the facial skin around the left and right temporomandibular joints stretches and contracts to the same extent, as shown in Figure 3(b). Therefore, the difference between the resistance value of strain sensor 1A and the resistance value of strain sensor 1B received by the control unit 22 is small.

[0035] On the other hand, if there is a misalignment of the temporomandibular joint, as shown in Figure 3(c), the degree to which the user opens their mouth differs on the left and right sides, resulting in different degrees of stretching of the facial skin around the temporomandibular joint on the left and right sides. Therefore, the difference between the resistance value of strain sensor 1A and the resistance value of strain sensor 1B received by the control unit 22 will be larger than when there is no misalignment of the temporomandibular joint.

[0036] Thus, the difference between the resistance value of strain sensor 1A and the resistance value of strain sensor 1B changes depending on whether there is or is no misalignment of the temporomandibular joint. Therefore, it is desirable to set a threshold value that represents the boundary between the difference value when there is no misalignment of the temporomandibular joint and the difference value when there is misalignment of the temporomandibular joint, and store it in the memory unit 23. This allows the control unit 22 to appropriately determine whether or not there is misalignment of the temporomandibular joint. This threshold value may be predetermined when the measuring device 3 is shipped, or it may be possible to register and rewrite it by the user using the measuring device 3. In the latter case, for example, the user attaches the measuring device 3 once and has the measuring device 3 measure the resistance values ​​of each strain sensor when opening and closing the jaw. Based on these measurement results, the control unit 22 sets the aforementioned threshold value and stores it in the memory unit 23.

[0037] According to the above process, the measuring device 3 can easily measure the distortion of the temporomandibular joint. Furthermore, since the displacement of the temporomandibular joint can be measured simply by attaching strain sensors 1A and 1B to the skin of the user's face, it is hygienic. In addition, the measuring device 3 does not require a special sensor holder to hold the strain sensors 1A and 1B, and the strain sensors 1A and 1B can be easily attached and detached. Therefore, a measuring device that is highly convenient for the user can be realized.

[0038] In this embodiment, an example in which one strain sensor is provided on each side of the face has been described. However, multiple strain sensors may be provided on both the right and left sides of the face. In this case, it is desirable that at least one strain sensor on each side be attached near the user's temporomandibular joint. When multiple strain sensors are provided on both the right and left sides of the face, the control unit 22 may compare the combined resistance value received from the strain sensor on the right side of the face with the combined resistance value received from the strain sensor on the left side of the face and take the difference between these values. Then, the control unit may compare this difference with a threshold value to determine whether or not there is a misalignment of the temporomandibular joint. Here, "combined" means, for example, taking the average, sum, maximum, or minimum value of the multiple resistance values.

[0039] [Strength Gauge Configuration] Next, the configuration of the strain gauge will be described with reference to Figures 4 and 5. Figure 4 shows an embodiment of the present invention. 1 This is a plan view illustrating a strain gauge related to the above. Figure 5 is an embodiment. 1 This is a cross-sectional view illustrating a strain gauge related to the above, showing a cross-section along line AA in Figure 4. While the configuration will be explained below using strain gauge 12a, strain gauges 12b, 12c, and 12d have a similar configuration.

[0040] Referring to Figures 4 and 5, the strain gauge 12a comprises a base material 121, a resistor 122, wiring 123 and 124, electrodes 125 and 126, and a cover layer 127. In Figure 4, for convenience, only the outer edge of the cover layer 127 is shown with a dashed line. The cover layer 127 can be provided as needed.

[0041] The strain gauge 12a shown in Figure 4 has the side of the base material 121 without any components attached to the user's skin or the beam portion of the strain sensor 1A. In the case where there is only one strain gauge in each sensor portion on the left and right, the strain generating body etc. described later is not provided, and one strain gauge becomes the sensor portion. In this case, the side of the base material 121 without any components is attached to the lower surface (back) of the beam portion 112a with adhesive or the like. Furthermore, the plan view in Figure 4 refers to viewing the object in the direction normal to the upper surface 121F of the base material 121 from the top to the bottom. The planar shape refers to the shape of the object when viewed in the aforementioned normal direction.

[0042] The base material 121 is a component that serves as a base layer for forming the resistor 122, etc. The base material 121 is flexible. The thickness of the base material 121 is not particularly limited, but may be, for example, about 5 μm to 500 μm. However, from the viewpoint of the transmission of strain from the outer surface of the strain-generating body or a component equivalent to the strain-generating body to the sensing part, and dimensional stability against environmental changes, the thickness of the base material 121 is preferably in the range of 5 μm to 200 μm. Furthermore, from the viewpoint of insulation, the thickness of the base material 121 is preferably 10 μm or more.

[0043] The base material 121 is formed from an insulating resin film such as PI (polyimide) resin, epoxy resin, PEEK (polyether ether ketone) resin, PEN (polyethylene naphthalate) resin, PET (polyethylene terephthalate) resin, PPS (polyphenylene sulfide) resin, LCP (liquid crystal polymer) resin, or polyolefin resin. Note that "film" refers to a flexible material with a thickness of approximately 500 μm or less.

[0044] When the base material 121 is formed from an insulating resin film, the insulating resin film may contain fillers, impurities, etc. For example, the base material 121 may be formed from an insulating resin film containing fillers such as silica or alumina.

[0045] Other materials for the substrate 121 besides resin include, for example, crystalline materials such as SiO2, ZrO2 (including YSZ), Si, Si2N3, Al2O3 (including sapphire), ZnO, and perovskite ceramics (CaTiO3, BaTiO3). In addition to the aforementioned crystalline materials, amorphous glass or the like may also be used as the material for the substrate 121. Furthermore, metals such as aluminum, aluminum alloys (duralumin), and titanium may be used as the material for the substrate 121. When a metal is used, an insulating film is provided on the metallic substrate 121.

[0046] The resistor 122 is a thin film formed in a predetermined pattern on the upper side of the substrate 121. In the strain gauge 12a, the resistor 122 is a sensitive part that receives strain and causes a change in resistance. The resistor 122 may be formed directly on the upper surface 121F of the substrate 121, or it may be formed on the upper surface 121F of the substrate 121 via another layer. For convenience, in Figure 4, the resistor 122 is shown with a dark matte pattern.

[0047] The resistor 122 has a structure in which multiple elongated sections are arranged at predetermined intervals with their longitudinal directions aligned in the same direction (± horizontal direction in the example of Figure 4), and the ends of adjacent elongated sections are connected alternately, so that the whole structure is folded in a zigzag pattern. The longitudinal direction of the multiple elongated sections becomes the grid direction, and the direction perpendicular to the grid direction becomes the grid width direction (vertical direction in the example of Figure 4).

[0048] In the resistor 122, the left end of the elongated uppermost section in Figure 4 bends upward to reach one end 122e1 in the grid width direction of the resistor 122. Similarly, the left end of the elongated lowermost section in Figure 4 bends downward to reach the other end 122e2 in the grid direction of the resistor 122. Each end 122e1 and 122e2 is electrically connected to electrodes 125 and 126 via wires 123 and 124. In other words, wires 123 and 124 electrically connect each end 122e1 and 122e2 in the grid width direction of the resistor 122 to their respective electrodes 125 and 126.

[0049] The resistor 122 can be formed from, for example, a material containing Cr (chromium), a material containing Ni (nickel), or a material containing both Cr and Ni. That is, the resistor 122 can be formed from a material containing at least one of Cr and Ni. An example of a material containing Cr is a Cr multiphase film. An example of a material containing Ni is Cu-Ni (copper nickel). An example of a material containing both Cr and Ni is Ni-Cr (nickel chromium).

[0050] Here, a Cr multiphase film is a film in which Cr, CrN, and Cr2N are mixed together. The Cr multiphase film may contain unavoidable impurities such as chromium oxide.

[0051] The thickness of the resistor 122 is not particularly limited, but may be, for example, around 0.05 μm to 2 μm. In particular, when the thickness of the resistor 122 is 0.1 μm or more, the crystallinity of the crystal constituting the resistor 122 (for example, the crystallinity of α-Cr) is improved. Also, when the thickness of the resistor 122 is 1 μm or less, (i) cracks in the film and (ii) warping of the film from the substrate 121, caused by internal stress in the film constituting the resistor 122, are reduced.

[0052] Considering the need to minimize lateral sensitivity and prevent wire breakage, the width of the resistor 122 is preferably 10 μm or more and 100 μm or less. More specifically, the width of the resistor 122 is preferably 10 μm or more and 70 μm or less, and more preferably 10 μm or more and 50 μm or less.

[0053] For example, if the resistor 122 is a Cr multiphase film, the stability of the gauge characteristics can be improved by making α-Cr (alpha-chromium), a stable crystalline phase, the main component. Also, for example, if the resistor 122 is a Cr multiphase film, by making α-Cr the main component of the resistor 122, the gauge factor of the strain gauge 12a can be set to 10 or more, and the gauge factor temperature coefficient TCS and resistance temperature coefficient TCR can be set within the range of -1000 ppm / ℃ to +1000 ppm / ℃. Here, "main component" means a component that accounts for 50% by weight or more of the total material constituting the resistor. From the viewpoint of improving gauge characteristics, it is preferable that the resistor 122 contains 80% by weight or more of α-Cr. Furthermore, from the same viewpoint, it is even more preferable that the resistor 122 contains 90% by weight or more of α-Cr. Note that α-Cr is Cr with a bcc structure (body-centered cubic lattice structure).

[0054] Furthermore, if the resistor 122 is a Cr multiphase film, it is preferable that the amount of CrN and Cr2N contained in the Cr multiphase film be 20% by weight or less. By having CrN and Cr2N contained in the Cr multiphase film be 20% by weight or less, a decrease in the gauge factor of the strain gauge 12a can be suppressed.

[0055] Furthermore, in the Cr multiphase film, it is preferable that the ratio of CrN to Cr2N is such that the proportion of Cr2N is 80% or more and less than 90% by weight relative to the total weight of CrN and Cr2N. More preferably, the ratio is such that the proportion of Cr2N is 90% or more and less than 95% by weight relative to the total weight of CrN and Cr2N. Cr2N has semiconducting properties. Therefore, by setting the proportion of Cr2N to 90% or more and less than 95% by weight as described above, the decrease in TCR (negative TCR) becomes even more pronounced. Moreover, by setting the proportion of Cr2N to 90% or more and less than 95% by weight as described above, the ceramicization of the resistor 122 can be reduced, making brittle fracture of the resistor 122 less likely to occur.

[0056] On the other hand, CrN also has the advantage of being chemically stable. By including more CrN in the Cr multiphase film, the possibility of unstable nitrogen generation can be reduced, thus enabling the creation of a stable strain gauge. Here, "unstable nitrogen" refers to trace amounts of N2 or atomic nitrogen that may be present in the Cr multiphase film. These unstable nitrogen atoms may escape from the film depending on the external environment (e.g., high temperature environment). When unstable nitrogen atoms escape from the film, the film stress of the Cr multiphase film may change.

[0057] Wires 123 and 124 are provided on the base material 121. Wires 123 and 124 are electrically connected to the resistor 122 and electrodes 125 and 126. Wires 123 and 124 are not limited to being linear and can be arranged in any pattern. Also, wires 123 and 124 can have any width and length. For convenience, in Figure 4, wires 123 and 124 are shown with a textured surface that is thinner than the resistor 122.

[0058] Electrodes 125 and 126 are provided on the substrate 121. Electrodes 125 and 126 are electrically connected to the resistor 122 via wiring 123 and 124. In a plan view, electrodes 125 and 126 are wider than wiring 123 and 124 and are formed in a roughly rectangular shape. Electrodes 125 and 126 are a pair of electrodes for outputting to the outside the change in the resistance value of the resistor 122 caused by strain. Lead wires (not shown) for external connection are joined to electrodes 125 and 126. A layer of a metal with low resistance, such as copper, or a layer of a metal with good solderability, such as gold, may be laminated on the upper surface of electrodes 125 and 126. Although the resistor 122, wiring 123 and 124, and electrodes 125 and 126 are given different reference numerals for convenience, they can all be formed integrally from the same material in the same process. Note that in Figure 4, for convenience, electrodes 125 and 126 are shown with the same textured pattern as wiring 123 and 124.

[0059] The cover layer 127 is provided on the substrate 121 as needed. The cover layer 127 is provided on the upper surface 121F of the substrate 121 so as to cover the resistor 122 and wiring 123, 124 and expose the electrodes 125, 126. Examples of materials for the cover layer 127 include insulating resins such as PI resin, epoxy resin, PEEK resin, PEN resin, PET resin, PPS resin, and composite resins (e.g., silicone resin, polyolefin resin). The cover layer 127 may also contain fillers and pigments. The thickness of the cover layer 127 can be, for example, about 2 μm to 30 μm. By providing the cover layer 127, mechanical damage to the resistor 122 can be suppressed. In addition, by providing the cover layer 127, the resistor 122 can be protected from moisture and other elements.

[0060] In the strain gauge 12a, using a Cr multiphase film as the material for the resistor 122 makes it possible to achieve higher sensitivity and miniaturization. For example, while the output of a conventional strain gauge was about 0.04mV / 2V, using a Cr multiphase film as the material for the resistor 122 makes it possible to obtain an output of 0.3mV / 2V or higher. Furthermore, while the size (gauge length × gauge width) of a conventional strain gauge was about 3mm × 3mm, using a Cr multiphase film as the material for the resistor 122 makes it possible to miniaturize the size (gauge length × gauge width) to about 0.3mm × 0.3mm.

[0061] Therefore, the strain gauge 12a using a Cr multiphase film as the material for the resistor 122 can be compactly installed on the strain generating body or an equivalent component, thus reducing discomfort for the user when applied to strain sensors 1A to 1F worn by the user. Furthermore, the strain gauge 12a using a Cr multiphase film as the material for the resistor 122 has higher resistance than conventional strain gauges. Therefore, when the strain gauge 12a is powered by a battery 15, lower power consumption is possible, extending battery life and allowing for longer or more repeated measurement of jaw movement.

[0062] (Other layered structures of strain gauges) Figure 6 shows an embodiment. 1 This is a cross-sectional view showing another example of a strain gauge. Figure 6 shows the cross-sectional shape of strain gauge 12a-1 when a functional layer 128 is provided as a base layer for the resistor 122, wiring 123, 124, and electrodes 125, 126.

[0063] The planar shape of the functional layer 128 may be patterned to be substantially the same as the planar shapes of, for example, the resistors 122, the wirings 123 and 124, and the electrodes 125 and 126. However, the planar shapes of the functional layer 128 and those of the resistors 122, the wirings 123 and 124, and the electrodes 125 and 126 do not have to be substantially the same. For example, if the functional layer 128 is formed from an insulating material, the functional layer 128 may be patterned to be a different shape from the planar shapes of the resistors 122, the wirings 123 and 124, and the electrodes 125 and 126. In this case, the functional layer 128 may be formed as a solid in the region where the resistors 122, the wirings 123 and 124, and the electrodes 125 and 126 are formed. Alternatively, the functional layer 128 may be formed as a solid over the entire upper surface of the substrate 121.

[0064] In this configuration, by providing a functional layer 128 beneath the metal layer on which components such as wiring are formed, crystal growth in the metal layer can be promoted, and a metal layer consisting of a stable crystalline phase can be produced. As a result, the stability of the gauge characteristics of the strain gauge 12a-1 is improved. Alternatively, the gauge characteristics of the strain gauge 12a-1 are improved by the diffusion of the material constituting the functional layer into the metal layer.

[0065] [Embodiment 2] The measuring device of the present disclosure may include a band that covers the side of the face, including at least the portion of the user's mandible and temporomandibular joint, and an actuator that can adjust the length and / or tightening force of the band. Embodiment 2 of the present disclosure will be described below with reference to Figure 7. In this embodiment, parts that are the same as those in Embodiment 1 will not be repeated in the description.

[0066] Figure 7 shows an overview of the measuring device 30 according to this embodiment. The measuring device 30 differs from the measuring device 3 according to Embodiment 1 in that it includes a band 4 and an actuator 5. In addition, the measuring device 30 shown in Figure 7 includes strain sensors 1C to 1F as additional strain sensors, in addition to strain sensors 1A and 1B. Strain sensors 1A, 1C, and 1E are arranged on the left side of the face, and strain sensors 1B, 1D, and 1F are arranged on the right side of the face, as shown in the figure.

[0067] Band 4 is a band that covers the sides of the user's face, including at least the portion of the mandibular and temporomandibular joint. The material, size, and shape of Band 4 are not particularly limited, as long as its length and / or tightening force can be adjusted by the actuator 5. In this embodiment, strain sensors 1A to 1F are fixed to Band 4. When the user puts on Band 4, the strain sensors 1A to 1F come into contact with the user's facial skin (i.e., each strain sensor is attached to the user).

[0068] As will be explained in more detail later, the length and / or clamping force of band 4 are adjusted by actuator 5. Therefore, it is desirable that the strain sensors 1A to 1F in band 4 be fixed in such a way that their placement and relative positions do not change drastically even if the length and / or clamping force of band 4 changes.

[0069] Actuator 5 is a device that adjusts the length and / or tightening force of band 4. Actuator 5 according to this embodiment includes the information processing device 2 described in Embodiment 1 and also functions as the information processing device 2. Actuator 5 adjusts the length and / or tightening force of band 4 by driving a drive device such as a motor built into the actuator 5 according to the determination result in the control unit 22. For example, Actuator 5 operates a gear attached to band 4 by driving a motor according to the determination result of the control unit 22. Then, the length and / or tightening force of band 4 is adjusted by winding or unwinding the band 4 through the operation of the gear.

[0070] For example, if the control unit 22 determines that there is "no displacement of the temporomandibular joint," the actuator 5 does not operate. On the other hand, if there is a displacement of the temporomandibular joint, the actuator 5 shortens the length of the band 4 on either the left or right side of the control unit 22 where the strain (i.e., the resistance value of the strain sensor) was greater, and / or increases the tightening force. This reduces the difference in strain between the left and right temporomandibular joints, thereby correcting the displacement of the temporomandibular joint. Furthermore, if the control unit 22 identifies an index indicating the degree of temporomandibular joint displacement, the actuator 5 may change the degree of adjustment of the length of the band 4 and / or the tightening force according to the index. For example, if the index is "large displacement," the length of the band 4 may be shortened and / or the tightening force may be increased compared to "small displacement."

[0071] Through the above process, the measuring device 30 can not only identify whether or not there is a misalignment of the temporomandibular joint, but also correct the misalignment of the temporomandibular joint.

[0072] [Embodiment 3] The strain sensors 1A and 1B described in Embodiment 1 may have a circumferential outer portion and a cross-shaped beam portion, and the strain sensors 1A and 1B may be provided on the cross-shaped beam portion. Hereinafter, the strain sensors 1A and 1B according to this embodiment will be described with reference to Figures 8 to 9. In the following description, strain sensor 1A will be described as an example, but strain sensor 1B may have a similar configuration. Furthermore, when two or more strain sensors are provided, additional strain sensors (for example, strain sensors 1C to 1F) may have a similar configuration to strain sensor 1A.

[0073] Figure 8 is a perspective view showing the pressure detection side of the strain sensor 1A in its standalone state. Figure 9 is a front view of the pressure detection side of the strain sensor 1A.

[0074] Referring to Figure 8, the strain sensor 1A is enclosed by the housing 10 except for the pressure detection surface that comes into contact with the skin. The housing 10 has a cylindrical wall 101 and a rear wall (not shown).

[0075] Furthermore, a strain-generating body 11 is provided on the pressure-sensing surface where the housing 10 is absent, with multiple strain gauges 12a, 12b, 12c, and 12d attached to it.

[0076] Furthermore, on the pressure detection surface, an annular adhesive portion 18 is provided on the outer circumference of the strain generating body 11. In Embodiment 1, the pressure detection surface side of the adhesive portion 18 is made of a material that adheres to the skin. In Embodiment 2, however, since the strain sensors 1A to 1F are also made to be pressed against the skin by wrapping the band 4 around them, the pressure detection surface side of the adhesive portion 18 does not need to be adhesive, and is made of a cushioning sponge material or the like to improve skin contact. Alternatively, Embodiment 2 Therefore, the attachment portion 18 does not necessarily have to be provided.

[0077] Furthermore, a control board (not shown), which is a flexible circuit board, is provided inside the housing 10. On the control board are the AFE 13 shown in Figure 2, a signal processing unit 14, a battery 15, and a communication unit 16. The strain gauges 12a, 12b, 12c, and 12d are connected to the AFE 13 by lead wires.

[0078] Referring to Figures 8 and 9, the strain generating body 11 has a base portion 111, beam portions 112a, 112b, 112c, and 112d, a load portion 113, and stretched portions 114a, 114b, 114c, and 114d. The strain generating body 11 has a shape that is four-fold symmetrical in plan view, for example. As the material for the strain generating body 11, for example, stainless steel (SUS), copper, and aluminum can be used. The strain generating body 11 is, for example, in the shape of a flat plate, and each component is integrally formed by, for example, a press working method. In the strain generating body 11, the beam portions 112a, 112b, 112c, and 112d may be flat, or they may have a dome-like or other protruding shape such that the pressure detection side is convex. The thickness of the strain generating body 11, excluding the load portion 113, is, for example, constant, and is between 0.01 mm and 0.25 mm.

[0079] In the strain sensor 1A, the housing 10 is the part that holds the strain generating body 11. The housing 10 is cylindrical, with the outside closed and the pressure detection side open. The housing 10 can be made of, for example, metal or resin. A roughly disc-shaped strain generating body 11 is fixed to the housing 10 with adhesive or the like so as to close the opening on the pressure detection side. The strain generating body 11 has a plurality of strain gauges 12a, 12b, 12c, and 12d arranged on it, and is the part that detects the amount of strain.

[0080] In the strain generating body 11, the base portion 111 is the circular frame-shaped (ring-shaped) region outside the circular dashed line shown in Figures 8 and 9. The region inside the circular dashed line is sometimes referred to as the circular opening. In other words, the base portion 111 of the strain generating body 11 has a circular opening. The width w1 of the base portion 111 is, for example, 1 mm or more and 5 mm or less. The inner diameter d of the base portion 111 (i.e., the diameter of the circular opening) is, for example, 5 mm or more and 40 mm or less.

[0081] The beam sections 112a, 112b, 112c, and 112d are provided to bridge the inside of the base 111. Each beam section 112a, 112b, 112c, and 112d has, for example, two beams that intersect in a cross shape in plan view, and the region where the two beams intersect includes the center of the circular opening. One beam forming the cross has its longitudinal direction in the horizontal direction of Figure 9, and the other beam forming the cross has its longitudinal direction in the vertical direction of Figure 9, and the two are perpendicular to each other. It is preferable that each of the two perpendicular beams is located inside the inner diameter d (diameter of the circular opening) of the base 111 and is as long as possible. In other words, it is preferable that the length of each beam is approximately equal to the diameter of the circular opening. In each beam forming the beam sections 112a, 112b, 112c, and 112d, the width w2 outside the intersecting region is constant, for example, 1 mm or more and 5 mm or less. While it is not essential that the width w2 be constant, it is preferable because it allows for linear detection of strain.

[0082] The load section 113 is located in the center of the beam sections 112a, 112b, 112c, and 112d. The load section 113 is located, for example, in the region where two beams constituting the beam sections 112a, 112b, 112c, and 112d intersect. The load section 113 protrudes from the upper surface (pressure detection surface) of the beam sections 112a, 112b, 112c, and 112d. The amount of protrusion of the load section 113 relative to the upper surface of the beam sections 112a, 112b, 112c, and 112d is, for example, about 0.1 mm. The beam sections 112a, 112b, 112c, and 112d are flexible and elastically deform when a load is applied to the load section 113.

[0083] The four extensions 114a, 114b, 114c, and 114d are fan-shaped portions that extend from the inside of the base 111 toward the center in a plan view, between the beam portions 112a, 112b, 112c, and 112d. A gap of about 1 mm is provided between each extension 114a, 114b, 114c, and 114d and the beam portions 112a, 112b, 112c, and 112d. If this gap is set to, for example, about 0.05 to 0.2 mm, it is possible to prevent contamination from entering the inside of the housing 10 from the outside. The extensions 114a, 114b, 114c, and 114d do not contribute to the sensing of the strain sensor 1A and therefore do not need to be provided.

[0084] In the strain sensor 1A, the central load portion 113 of the strain generating body 11 protrudes from an opening in the cylindrical wall 101 of the housing 10 and is attached to the position of the user's temporomandibular joint, which is the object of measurement, in a state where it can come into contact with the user's skin.

[0085] In the strain sensor 1A, it is preferable that the load portion 113 of the strain generating body 11 protrudes outward from the attachment portion 18 before attachment. When the load portion 113 protrudes outward (towards the user's skin), it is preferable that the amount of protrusion before attachment be about 3 mm to 7 mm.

[0086] This protruding configuration ensures that even when the strain sensor 1A is attached to the temporomandibular joint, jaw angle, or temporalis muscle, the strain sensor 1A does not protrude, and an appropriate initial pressure is applied to the outer surface of the skin or scalp, allowing the strain sensor 1A to exhibit a predetermined resistance value even at its initial state.

[0087] The strain gauges 12a, 12b, 12c, and 12d are provided on one side of the strain generating body 11. The strain gauges 12a, 12b, 12c, and 12d can be provided, for example, on the back side of the beam sections 112a, 112b, 112c, and 112d that faces the pressure detection surface. Since the beam sections 112a, 112b, 112c, and 112d are flat plates, the strain gauges can be easily attached to them. One or more strain gauges 12a, 12b, 12c, and 12d are sufficient, but in this embodiment, four strain gauges 12a, 12b, 12c, and 12d are provided. By providing four strain gauges 12a, 12b, 12c, and 12d, strain can be detected by full bridge. This allows for the detection of the direction of tilt (strain) when tilt occurs in the strain-generating body of the strain sensor.

[0088] As shown in Figure 9, two of the four strain gauges, 12b and 12d, are positioned on the side of the beam closer to the load section 113 (towards the center of the circular opening), facing each other in a plan view, with the load section 113 in between. The other two of the four strain gauges, 12a and 12c, are positioned on the side of the beam closer to the base 111, facing each other in a plan view, with the load section 113 in between. This arrangement allows for effective detection of compressive and tensile forces, enabling greater output from the full bridge.

[0089] The strain sensor 1A is used by attaching it so that the load portion 113 is in contact with the skin at the location of the user's temporomandibular joint. When a load is applied to the load portion 113 in response to the movement of the temporomandibular joint, the beam portions 112a, 112b, 112c, and 112d elastically deform, and the resistance values ​​of the resistors of the strain gauges 12a, 12b, 12c, and 12d change. Based on the change in the resistance values ​​of the resistors of the strain gauges 12a, 12b, 12c, and 12d accompanying the deformation of the beam portions 112a, 112b, 112c, and 112d, the strain sensor 1A can detect the strain of the temporomandibular joint.

[0090] <Example 1> In the measuring device 30 shown in Embodiment 2, the actuator 5 and the information processing device 2 may be provided as separate devices. In this case, the information processing device 2 and the actuator 5 are connected in a communicative manner. When the control unit 22 of the information processing device 2 receives resistance values ​​from each strain sensor, it identifies whether or not there is a misalignment of the left and right temporomandibular joints (and an index indicating the degree of misalignment), as shown in Embodiment 1.

[0091] If there is no misalignment of the temporomandibular joint, the control unit 22 does not perform any special processing (the display unit 24 may display the result). On the other hand, if there is a misalignment of the temporomandibular joint, the control unit 22 transmits information to the actuator 5 via the communication unit 21 indicating which side of the temporomandibular joint has greater distortion. If an index for the misalignment of the temporomandibular joint has been identified, the control unit 22 also transmits that index to the actuator 5.

[0092] The actuator 5 adjusts the length and / or tightening force of the band 4 based on the information received from the information processing device 2. For example, if only information indicating which side of the temporomandibular joint has greater distortion is received, the actuator 5 shortens the length of the part of the band 4 with greater distortion and / or increases the tightening force. This reduces the difference in distortion between the left and right temporomandibular joints, thereby correcting the misalignment of the temporomandibular joint.

[0093] [Embodiment 4] In the embodiments and their modifications described above, the case in which the sensor unit (strain sensors 1A and 1B) according to the present disclosure includes a strain gauge using a resistor was explained. That is, the above embodiments described the case in which the strain gauge according to the present disclosure is an electrical resistance type metal strain gauge. However, the strain gauge included in the sensor unit according to the present disclosure is not limited to a metal strain gauge. For example, the strain gauge according to the present disclosure may be a strain gauge that detects magnetic changes caused by pressure and / or strain applied to a strain-generating body (or a structure equivalent to a strain-generating body) using a detection element included in the strain gauge.

[0094] Specifically, the sensor unit according to this disclosure may include a strain gauge having a detection element that utilizes the Villari phenomenon (described later). Furthermore, the sensor unit according to this disclosure may include a strain gauge having a detection element having a magnetic tunnel junction structure (described later). Hereinafter, Embodiment 4 will describe a strain gauge including a detection element that utilizes the Villari phenomenon. Furthermore, Embodiment 5 will describe a strain gauge including a detection element having a magnetic tunnel junction structure.

[0095] In each embodiment of this specification, components having similar functions will be given the same name and component number, and their descriptions will not be repeated. Furthermore, the directions of the x, y, and z axes in the drawings of each embodiment thereafter (drawings from Figure 10 onwards) are the same as the directions of the x, y, and z axes shown in Figures 4 to 6. In the following description, the positive direction of the z axis will be referred to as "up," and the negative direction of the z axis will be referred to as "down." That is, in the following description, "upper side" refers to the side in the positive direction of the z axis, and "upper surface" refers to the surface on the positive direction of the z axis. Similarly, "lower side" refers to the side in the negative direction of the z axis, and "lower surface" refers to the surface on the negative direction of the z axis.

[0096] Figure 10 shows an example of a detection element 300 included in a strain gauge according to Embodiment 4. Figure 10(a) is a plan view of the detection element 300 when viewed from the positive z-axis direction to the negative z-axis direction (i.e., from the top surface to the bottom surface). On the other hand, Figure 10(b) shows a cross-sectional view of the detection element 300 shown in Figure 10(a) along the α-α' line. Note that the wiring extending from the detection element 300 is not shown in Figures 10(a) and (b). However, the detection element 300 may be connected to wiring that connects the drive coil 320 and the power supply, which will be described later, and to wiring that transmits the current detected by the sensing coil 380.

[0097] As shown in Figure 10(a), the detection element 300 includes a drive coil 320, a sensing coil 380, and a base layer 310. The base layer 310 is the core layer for the drive coil 320 and the sensing coil 380. The sensing coil 380 is a coil for detecting the magnetization strength of the base layer 310 (more precisely, the base metal 370 described later). The drive coil 320 is a coil for generating a magnetic field. The detection element 300 has a double structure with the base layer 310 as the core material, with the sensing coil 380 wound on the inside and the drive coil 320 wound on the outside. The materials for the drive coil 320 and the sensing coil 380 are preferably conductive metals such as Cu, Ag, Al, and Au, or alloys of these metals. The number of turns and the size of the cross-sectional area of ​​the drive coil 320 and the sensing coil 380 may be appropriately designed according to the strain detection sensitivity required for the detection element 300.

[0098] As will be explained in detail later, when stress is applied to the base layer 310, the magnetization strength of the base metal 370 (described later) contained in the base layer 310 changes. The detection element 300 can determine the strength of the stress (i.e., the degree of strain) applied to the base layer 310 by detecting this change in magnetization strength with the sensing coil 380.

[0099] The configuration of the detection element 300 will be further explained with reference to the cross-sectional view in Figure 10(b). In Figure 10(b), the drive coil 320, the sensing coil 380, and the three insulating layers 340, 350, and 360 are each formed to surround the core material, the base metal 370. That is, the layers with the same component number in Figure 10(b) are connected and surround the base metal 370.

[0100] The base metal 370 is a core material for various coils and insulating layers. The base metal 370 may be, for example, a substantially flat metal plate. The base metal 370 is covered so as to surround it with the insulating layer 360. Preferably, the base metal 370 is made of a soft magnetic material such as an Fe-Si-Al alloy such as Sendust, or a Ni-Fe alloy such as Permalloy. The aforementioned base layer 310 consists of this base metal 370 and the insulating layer 360, as shown in Figure 10(b).

[0101] Outside the insulating layer 360, an insulating layer 350 is formed so as to surround the insulating layer 360. Further outside the insulating layer 350, an insulating layer 340 is formed. The insulating layer 350 is a layer containing the sensing coil 380, and the gaps around the sensing coil 380 are filled with insulating material. The insulating layer 340 is a layer containing the drive coil 320, and the gaps around the drive coil 320 are filled with insulating material. It is preferable that the insulating layers 340, 350, and 360 are made of a dry film that is not affected by the magnetic field or a resist-cured material such as a photosensitive polyimide.

[0102] One side of the detection element 300 may be attached to the base material 110, as shown in Figure 10(b). The base material 110 is a member that fixes the detection element 300. For example, the base material 110 may be a flexible substrate made of plastic film or the like. The detection element 300 is attached to the strain generating body 11 via the base material 110. The detection element 300 may be a flat plate or a thin film as a whole. If the detection element 300 is a flat plate or a thin film, the detection element 300 can be easily attached to the base material 110. Furthermore, the base material 110 is not an essential component of the detection element 300. For example, the detection element 300 may be used without a base material 110, by directly attaching the bottom surface of the detection element 300 to the strain generating body 11.

[0103] The strain-generating body 11 according to this embodiment may have basically the same configuration and materials as the strain-generating body 11 according to Embodiments 1 to 3 and their modified versions. However, in this embodiment, it is more desirable that the strain-generating body 11 be made of a non-magnetic material. The strain-generating body 11 according to this embodiment can be made from, for example, non-magnetic stainless steel.

[0104] Next, the principle of detecting strain using the detection element 300 will be outlined. The detection element 300 includes a base metal 370, which is a magnetic material. When an alternating current is supplied from the power source to the drive coil 320, the drive coil 320 generates an alternating magnetic field around it. This generates a magnetic field, and the base metal 370 is magnetized. When the strain-generating body 11 deforms in this state, strain occurs. The strain is transmitted through the substrate 110, and stress is applied to the base metal 370. If the detection element 300 is attached to the strain-generating body 11 without going through the substrate 110, the stress is transmitted directly from the strain-generating body 11 to the base metal 370 (and the insulating layers 340-360 covering it).

[0105] When stress is applied to the base metal 370, the permeability of the base metal 370 changes according to that stress. Consequently, the magnetization strength (degree of magnetization) of the base metal 370 changes. This phenomenon, in which the permeability and magnetization strength of a magnetic material change when stress is applied to it, is called the "Villari phenomenon." According to the configuration of the detection element 300, an AC voltage corresponding to the magnetization strength of the base metal 370 is induced in the sensing coil 380, which is the pickup coil. Therefore, based on the principle of the Villari phenomenon, the stress applied to the base metal 370 can be calculated from the value of this AC voltage. Then, the degree of strain of the strain-generating body 11 can be determined from the calculated stress. Note that if the detection element 300 has the shape shown in Figures 10(a) and (b), the grid direction of the detection element 300 is equal to the α-α' direction in Figure 10(a). Based on the principle described above, the detection element 300 can detect the strain of the strain-generating body 11. In other words, the detection element 300 functions as a detection element in the sensor unit.

[0106] Furthermore, it is desirable that the drive coil 320 be wound as uniformly as possible around the outside of the sensing coil 380 and over the entire region in which the sensing coil 380 is present. This allows for a more uniform application of the alternating magnetic field to the entire region of the base metal 370 in which the sensing coil 380 is present. As a result, changes in the magnetization strength of the base metal 370 due to the vilari phenomenon can be detected more precisely. Therefore, the performance of the detection element 300 is improved.

[0107] Furthermore, the insulating layer 360 may be formed on only a part of the base metal 370, rather than the entirety of it. For example, the portion of the base metal 370 around which the sensing coil 380 and the drive coil 320 are wound may be covered with the insulating layer 360, the insulating layer 360 may be covered with an insulating layer 350 including the sensing coil 380, and the insulating layer 350 may be further covered with an insulating layer 340 including the drive coil 320.

[0108] Furthermore, if the base metal 370 is substantially flat, the insulating layer 360 may be formed to surround the base metal 370 only in the direction in which the coil is wound. That is, in Figure 10(b), both ends of the base metal 370 in the x direction do not need to be covered by the insulating layer 360.

[0109] In the measuring device according to this embodiment, when the strain-generating body 11 deforms (i.e., strain occurs in the strain-generating body), the base material 110 of the strain gauge (or the detection element 300 itself) is strained. The detection element 300 can detect the magnetic change caused by this strain based on the principle of the Villari phenomenon described above. The sensor unit, including the detection element 300, outputs the detection result to the information processing device 2. As a result, the measuring device according to Embodiment 4 can determine whether or not there is a distortion in the user's temporomandibular joint based on the output of the sensor unit, similar to the measuring devices according to Embodiments 1 to 3.

[0110] The strain gauge including the detection element 300 according to this embodiment can be arranged on the strain generating body 11 in any arrangement pattern shown in Embodiments 1 to 3 and their modified versions. That is, the strain of the strain generating body 11 can be detected using the detection element 300 according to this embodiment, in the same way as when using an electrical resistance type strain gauge. Therefore, the strain gauge according to this embodiment has the same effects as the strain gauges according to Embodiments 1 to 3 and their modified versions.

[0111] [Embodiment 5] Figure 11 shows a detection element 500, which is an example of a detection element included in the strain gauge according to Embodiment 5. Figure 12 shows a detection element 600, which is another example of a detection element included in the strain gauge according to Embodiment 5. Figure 13 shows a detection element 700, yet another example of a detection element included in the strain gauge according to Embodiment 5. Figures 11 to 13(a) are perspective views of the detection elements 500, 600, and 700, respectively. Figures 11 to 13(b) are plan views of the detection elements 500, 600, and 700 viewed from the positive z-axis to the negative z-axis. Figures 11 to 13(c) are cross-sectional views of the detection elements 500, 600, and 700 in a plane parallel to the zx-plane. Note that wiring extending from the detection elements is not shown in any of the figures 11 to 13. However, these detection elements 500, 600, and 700 may also be connected to wiring that connects the upstream electrode 510 to the power supply and wiring that connects the downstream electrode 520 to the power supply, as described later.

[0112] As shown in Figures 11-13(a), the detection elements 500, 600, and 700 include an upstream electrode 510, a downstream electrode 520, a magnetic film 530, and an insulating film 540. The insulating film 540 is sandwiched between the magnetic film 530 as shown in the figure. A magnetic tunnel junction is formed by this magnetic film 530 and insulating film 540. In other words, the detection elements 500, 600, and 700 have a structure in which electrodes are connected to a magnetic tunnel junction structure.

[0113] The lower surfaces of the detection elements 500, 600, and 700 may be attached to a substrate similar to the substrate 121 according to Embodiments 1 to 3. The detection element 500 may be attached to the strain-generating body 11 via the substrate. The detection elements 500, 600, and 700 may be flat plates or thin films as a whole. If the detection elements 500, 600, and 700 are flat plates or thin films, they can be easily attached to the substrate or strain-generating body 11. Alternatively, for example, the lower surfaces of the detection elements 500, 600, and 700 may be directly attached to the strain-generating body 11 for use.

[0114] The magnetic film 530 is a magnetic nanothin film. The insulating film 540 is an insulating nanothin film. The materials of the magnetic film 530 and the insulating film 540 are not particularly limited, as long as a magnetic tunnel junction structure can be formed. For example, cobalt iron boron, or 3d transition metal ferromagnets such as Fe, Co, and Ni, and alloys containing them can be used as the magnetic film 530. Also, silicon oxide, silicon nitride, aluminum oxide, magnesium oxide, etc. can be used as the insulating film 540.

[0115] The upstream electrode 510 and the downstream electrode 520 are electrodes for applying a voltage to the magnetic tunnel junction structure. In the examples in Figures 11-13, the current flows from the upstream electrode 510 to the downstream electrode 520. For example, in Figure 11(c), when a voltage is applied between the upstream electrode 510 and the downstream electrode 520, electrons flow from the upper (positive z-axis) magnetic film 530, across the insulating film 540, to the lower (negative z-axis) magnetic film 530. This phenomenon is called the "tunneling effect," and the electrical resistance when electrons pass through the insulating film 540 is called the "tunneling resistance." In the examples in Figures 11-13, the junctions of each part of the electrodes are treated at the ends to prevent current from short-circuiting the magnetic tunnel junction structure.

[0116] Incidentally, when strain is applied to the detection element 500 via the substrate 110, a magnetic change occurs in the tunnel junction structure. More specifically, the magnetization directions of the upper and lower magnetic films 530 are misaligned. When the magnetization directions of the upper and lower magnetic films 530 are misaligned in this way, the tunnel resistance increases compared to when the magnetization directions are parallel (tunnel magnetoresistance effect). Therefore, in the detection element 500 having the above configuration, the current flowing between the electrodes decreases in proportion to the magnitude of the strain in the detection element 500 (more precisely, the magnetic tunnel junction portion). That is, as the strain increases, the electrical resistance increases. In this way, the detection element 500 can detect strain based on the current value in relation to the applied voltage. Therefore, by attaching the detection element 500 to the strain generating body 11, the strain applied to the strain generating body 11 can be measured.

[0117] The detection element having a magnetic tunnel junction structure is not limited to the example shown in Figure 11. For example, detection elements 600 and 700 as shown in Figures 12 and 13 can also be used. Both the detection element 600 shown in Figure 12 and the detection element 700 shown in Figure 13 are composed of an upstream electrode 510, a downstream electrode 520, a magnetic film 530, and an insulating film 540, and the principle of detecting strain by these components is the same as that of the detection element 500. The basic operation of the detection elements 600 and 700 is also the same as that of the detection element 500. The grid direction of the detection elements 500, 600, and 700 corresponds to the x-axis direction (positive and negative x-axis directions) in Figures 11 to 13, respectively. As shown in the figure, the detection element 600 shown in Figure 12 has a structure in which the upper magnetic film 530 and the lower magnetic film 530 are partially connected. In other words, a magnetic tunnel junction structure is formed only in a portion of the magnetic film 530, and a tunnel magnetoresistance effect occurs in this structure. On the other hand, the detection element 700 shown in Figure 13 is attached to the substrate 110 via the substrate 710. As shown in Figures 11 to 13, the design of the detection element may be modified as appropriate according to the required size, durability, and magnitude of stress to be detected, as long as it does not exceed the aforementioned principle.

[0118] The strain generating body 11 according to this embodiment may have basically the same configuration and materials as the strain generating body 11 according to Embodiment 3. However, in this embodiment, it is more desirable that the strain generating body 11 be made of a non-magnetic material. The strain generating body 11 according to this embodiment can be made from, for example, non-magnetic stainless steel. Also, the detection elements 500, 600, and 700 as a whole may have a substantially flat plate shape, such as a film type. This allows the detection elements 500 to be easily attached to the strain generating body 11. Furthermore, the detection elements 500, 600, and 700 may have a structure for applying a weak magnetic field to the structural parts of the magnetic tunnel junction, such as a drive coil. By applying a magnetic field to the structural parts of the magnetic tunnel junction, the tunnel magnetoresistance effect can be measured more stably, and thus strain can be detected stably.

[0119] Furthermore, the terms "upstream electrode" and "downstream electrode" in the detection elements 500, 600, and 700 are merely convenient designations, and the direction of current flow may be reversed. In other words, in the detection elements 500, 600, and 700 shown in Figures 11 to 13, the design may be such that current flows from the downstream electrode 520 to the upstream electrode 510.

[0120] In the measuring device according to this embodiment, when the strain-generating body 11 deforms (i.e., strain occurs in the strain-generating body), the base material of the strain gauge (or the detection element 500, 600, or 700 itself) is strained. The detection element 500, 600, or 700 can detect the magnetic change caused by this strain based on the principle of the tunnel magnetoresistance effect described above. The sensor unit, which includes a strain gauge having the detection element 500, 600, or 700, outputs the detection result to the information processing device 2. As a result, the measuring device according to Embodiment 5 can determine whether or not there is a distortion in the user's temporomandibular joint based on the output of the sensor unit, similar to the measuring devices according to Embodiments 1 to 3.

[0121] The strain gauges including the detection elements 500, 600, and 700 according to this embodiment can be arranged on the strain generating body 11 in any arrangement pattern shown in Embodiments 1 to 3 and their modified examples. That is, the strain of the strain generating body 11 can be detected using the detection elements 500, 600, and 700 according to this embodiment, in the same way as when using an electrical resistance type strain gauge. Therefore, the strain gauges according to this embodiment have the same effects as the strain gauges 12a, 12b, 12c, and 12d according to Embodiments 1 to 3 and their modified examples.

[0122] [Embodiment 6] The sensor unit according to this disclosure may include strain gauges or pressure sensors of a different type than those shown in Embodiments 1 to 3. For example, the sensor unit according to this disclosure may include semiconductor strain gauges, capacitive pressure sensors, or optical fiber strain gauges. Furthermore, the sensor unit according to this disclosure may include mechanical pressure sensors, vibratory pressure sensors, or piezoelectric pressure sensors. The principles of various strain gauges and pressure sensors will be explained below.

[0123] (Semiconductor strain gauge) Semiconductor strain gauges are strain gauges that detect strain by utilizing the pressure-resistive effect of semiconductors. In other words, semiconductor strain gauges are strain gauges that use semiconductors as strain detection elements.

[0124] It is known that when stress is applied to a semiconductor, strain occurs in the semiconductor's crystal lattice, changing the number and mobility of carriers in the semiconductor, and consequently changing its electrical resistance. Semiconductor strain gauges can be used by directly attaching them to a strain-generating body 11, similar to electrical resistance-type metal strain gauges. In this case, when the strain-generating body 11 expands or contracts, the attached semiconductor (more specifically, the semiconductor's crystal lattice) is strained, and its electrical resistance changes. Therefore, the amount of strain in the strain-generating body 11 can be determined by measuring this electrical resistance.

[0125] Furthermore, semiconductor strain gauges can also be configured as strain sensors equipped with a diaphragm structure. In this case, the strain sensor includes, for example, a non-metallic diaphragm (or a metal diaphragm with an electrically insulating layer formed on it) and a semiconductor (for example, a silicon thin-film semiconductor) formed on the diaphragm. In this structure including a diaphragm, when the diaphragm is strained by a normal stress applied to it, the electrical resistance of the semiconductor changes. Therefore, by measuring this electrical resistance, the amount of strain in the diaphragm (and consequently, the amount of strain in the strain-generating body 11) can be determined.

[0126] (Capacitive pressure sensor) A capacitive pressure sensor is a pressure sensor that measures the pressure applied to a diaphragm as a change in the capacitance of a pair of electrodes. In other words, a capacitive pressure sensor is a pressure sensor that uses a pair of electrodes as detection elements. A capacitive pressure sensor comprises, for example, a diaphragm as a movable electrode and one or more fixed electrodes. The diaphragm is formed of, for example, silicon containing impurities (i.e., silicon that functions as a conductor).

[0127] When pressure is applied to a diaphragm, the diaphragm is displaced, and the distance between the fixed electrode and the movable electrode changes. It is known that the capacitance between electrodes is determined by the distance between the electrodes, provided that the dielectric constant of the interelectrode medium and the area of ​​the electrodes are constant. Therefore, by measuring the capacitance, the amount of diaphragm displacement (i.e., the magnitude of the pressure) can be determined.

[0128] (Optical fiber strain gauge) An optical fiber strain gauge is a strain gauge that detects strain using an optical fiber on which a fiber Bragg grating (FBG) is formed. In other words, an optical fiber strain gauge is a strain gauge that uses an optical fiber as a strain detection element. The FBG is a diffraction grating that causes different light reflections in the optical fiber than in other parts of the optical fiber, and each of these gratings is formed at a constant interval. When the optical fiber is strained and stretched, the grating spacing of the FBG widens, so the wavelength of the reflected light of light incident on the optical fiber (e.g., laser light) changes. Conversely, when the optical fiber is strained and contracted, the grating spacing of the FBG narrows, so the wavelength of the reflected light of light incident on the fiber (e.g., laser light) changes.

[0129] By attaching an optical fiber having such characteristics to the strain-generating body 11 and measuring the wavelength spectrum of the reflected light from the optical fiber, the amount of strain in the optical fiber (i.e., the amount of strain in the strain-generating body 11) can be determined. Alternatively, an optical fiber strain gauge may be one that determines the amount of strain in the optical fiber from the change in the frequency of the Brillouin scattered light generated within the optical fiber.

[0130] (Mechanical pressure sensor) A mechanical pressure sensor is a sensor that determines the pressure acting on a mechanical structure by measuring the displacement of that structure. A mechanical pressure sensor, for example, is equipped with a spring or a bent tube, and measures the amount of expansion or contraction of the spring or the bent tube. These amounts of expansion or contraction (i.e., displacement) change according to the magnitude of the pressure acting on the spring or bent tube. Therefore, by measuring these amounts of expansion or contraction, the pressure acting on the spring or bent tube can be determined. The shape and size of the spring or bent tube may be appropriately determined according to the size and shape of the object to which the mechanical pressure sensor is attached.

[0131] (Vibration-type pressure sensor) A vibration pressure sensor is a sensor that detects pressure by utilizing the phenomenon that the natural frequency of an elastic beam changes due to the pressure (i.e., axial force) generated along the axis of the elastic beam. Like electrical resistance type metal strain gauges, vibration pressure sensors can be used by directly attaching them to the strain generating body 11. Alternatively, for example, a vibration pressure sensor may be a pressure sensor composed of a diaphragm formed on a substrate and a beam-shaped vibrator formed on the surface of the diaphragm.

[0132] In either case, when the strain-generating body 11 is deformed, the pressure is transmitted directly or indirectly to the oscillator, generating an axial force in the oscillator. The natural frequency of the oscillator changes according to the axial force. Therefore, by measuring the natural frequency of the oscillator, the magnitude of the pressure on the strain-generating body 11 can be determined.

[0133] (Piezoelectric pressure sensor) A piezoelectric pressure sensor is a sensor that contains a piezoelectric element (also called a piezo element) and detects pressure using the properties of this piezoelectric element. A piezoelectric element has the property of generating an electromotive force corresponding to the force applied and deforming (straining) when force is applied to it. In addition, a piezoelectric element has the property of expanding and contracting by generating a force corresponding to the voltage applied to it.

[0134] A piezoelectric pressure sensor can determine the force applied to a piezoelectric element (i.e., the amount of strain on the piezoelectric element) by measuring the electromotive force of the piezoelectric element. Therefore, by attaching the piezoelectric pressure sensor to the strain generating body 11, the amount of strain on the strain generating body 11 can be determined.

[0135] As described above, even when using semiconductor strain gauges, capacitive pressure sensors, optical fiber strain gauges, mechanical pressure sensors, vibratory pressure sensors, and piezoelectric pressure sensors, the strain of the strain-generating body 11 and / or the pressure applied to the strain-generating body 11 can be detected, similar to the strain gauges 12a, 12b, 12c, and 12d in Embodiments 1 to 3 and their modified versions. That is, the strain gauge or pressure sensor according to Embodiment 6 indirectly detects facial distortion at the positions of the user's left and right temporomandibular joints via the strain-generating body 11. The sensor unit, including the various strain gauges or pressure sensors of Embodiment 6, outputs the detection result to the information processing device 2. As a result, the measuring devices according to Embodiments 4 to 6 can determine whether or not there is distortion of the user's temporomandibular joint based on the output of the sensor unit, similar to the measuring devices according to Embodiments 1 to 3.

[0136] Furthermore, the strain gauges or pressure sensors according to Embodiments 4 to 6 may be attached directly to the user's skin (for example, the temporomandibular joint, the corner of the jaw, the skin in the area where the temporalis muscle is located, etc.) instead of the strain generating body 11. In this case, the strain gauges or pressure sensors according to Embodiments 4 to 6 directly receive the strain on the user's skin surface without going through the strain generating body 11. That is, in this case, the strain gauges or pressure sensors according to Embodiments 4 to 6, as each sensor unit, directly detect the facial distortion at the location of the user's left and right temporomandibular joints. The sensor unit, including the various strain gauges or pressure sensors according to Embodiments 4 to 6, then outputs the detection result to the information processing device 2. As a result, the measuring device having the sensor unit including the various strain gauges or pressure sensors according to Embodiments 4 to 6 can determine whether or not there is distortion in the user's temporomandibular joint based on the output of the sensor unit. Otherwise, the operation and effects of the strain gauges or pressure sensors according to Embodiments 4 to 6 are the same as those described above in each embodiment.

[0137] Preferred embodiments have been described in detail above. However, the measuring device relating to this disclosure is not limited to the embodiments and modifications described above. For example, various modifications and substitutions can be made to the measuring device relating to the embodiments described above without departing from the scope described in the claims. [Explanation of Symbols]

[0138] 1A, 1B, 1C, 1D, 1E, 1F Strain sensor (sensor part), 2 Information processing device, 3 Measuring device, 4 Band, 5 Actuator, 10 Housing, 11 Strain generating body, 12a, 12b, 12c, 12d Strain gauge (sensor part), 16 Communication unit, 18 Attachment unit, 20 Information processing device, 21 Communication unit, 22 Control unit (left / right difference identification unit), 23 Memory unit, 30 Measuring device, 300, 500, 600, 700 Detection element, 310 Base layer, 320 Drive coil, 340, 350, 360 Insulating layer, 370 Base metal, 380 Sensing coil, 510 Upstream electrode, 520 Downstream electrode, 530 Magnetic film, 540 Insulating film, 710 Substrate

Claims

1. a sensor unit that detects the distortion of the user's face at the positions of the left and right jaw joints as a resistance value; a left-right difference specifying unit that specifies whether or not the user has a distortion of the temporomandibular joint based on the resistance value output by the sensor unit, The measuring device has one or more sensor units attached to the left and right sides of the face at the positions of the temporomandibular joints.

2. a plurality of additional sensor units are provided on each of the left and right sides of the user's face, 2. The measuring device of claim 1, wherein the left-right difference determination unit determines whether or not the user has a distortion of the temporomandibular joint based on a resistance value obtained by combining the resistance values ​​output by the sensor unit located on the left side of the user's face and a resistance value obtained by combining the resistance values ​​output by the sensor unit located on the right side of the user's face.

3. A band that covers the side of the face including at least the user's lower jaw and forehead joint; an actuator capable of adjusting the length and / or fastening force of the band; The measuring device according to claim 1 or 2, wherein the actuator adjusts the length and / or the fastening force of the band depending on the degree of left-right distortion of the temporomandibular joint identified by the left-right difference identifying unit.

4. The measuring device according to claim 3 , wherein the sensor unit is fixed to the band, and when the user wears the band, the sensor unit is attached to the left and right sides of the user's face at the positions of the temporomandibular joints.

5. The measuring device according to claim 1 or 2, wherein the sensor unit is attached to the left and right sides of the user's face at the position of the temporomandibular joint by being adhered to the user's skin by a support having an adhesive layer.

6. The measurement device according to claim 1 , wherein the left-right difference specifying unit specifies an index indicating a degree of left-right deviation of the temporomandibular joint of the user based on a degree of left-right distortion of the temporomandibular joint.

7. The measuring device according to claim 1 or 2, wherein the sensor unit is a strain sensor or a strain gauge.

8. The sensor part is made of Cr, CrN, and Cr ２ 8. The measurement device of claim 7, comprising a strain gauge having a resistor formed from a film containing N.

9. a sensor unit that directly or indirectly detects facial distortion at the positions of the left and right temporomandibular joints of the user; a left-right difference specifying unit that specifies whether or not the user has a distortion of the temporomandibular joint based on an output of the sensor unit, The measuring device has one or more sensor units attached to the left and right sides of the face at the positions of the temporomandibular joints.

10. a plurality of additional sensor units are provided on each of the left and right sides of the user's face, 10. The measuring device according to claim 9, wherein the left-right difference determination unit determines whether or not the user has a distortion of the temporomandibular joint based on the overall output of a sensor unit arranged on the left side of the user's face and the overall output of a sensor unit arranged on the right side of the user's face.

11. A band that covers the side of the face including at least the user's lower jaw and forehead joint; an actuator capable of adjusting the length and / or fastening force of the band; The measuring device according to claim 9 or 10, wherein the actuator adjusts the length and / or the fastening force of the band depending on the degree of left-right distortion of the temporomandibular joint identified by the left-right difference identifying unit.

12. The measuring device according to claim 11, wherein the sensor unit is fixed to the band, and when the user wears the band, the sensor unit is attached to the left and right sides of the user's face at the position of the temporomandibular joint.

13. The measuring device according to claim 9 or 10, wherein the sensor unit is attached to the left and right sides of the user's face at the position of the temporomandibular joint by being adhered to the user's skin by a support having an adhesive layer.

14. The measurement device according to claim 9 , wherein the left-right difference specifying unit specifies an index indicating a degree of left-right deviation of the temporomandibular joint of the user based on a degree of left-right distortion of the temporomandibular joint.

15. The measuring device according to claim 9 or 10, wherein the sensor unit includes a strain gauge having a detection element that detects, as a magnetic change, pressure and / or strain applied to the sensor unit due to strain in the left and right temporomandibular joints of the user.

16. the detection element includes a magnetic material, The measuring device according to claim 15, wherein the detection element detects a change in the intensity of magnetization of the magnetic body when pressure is applied to the magnetic body due to pressure and / or strain applied to the sensor portion.

17. the detection element includes a magnetic tunnel junction structure in which an insulating film is sandwiched between magnetic films, The measuring device according to claim 15 , wherein the detection element detects a magnetic change occurring in the structure due to pressure and / or strain applied to the sensor portion.

18. The measuring device according to claim 9 or 10, wherein the sensor unit includes a semiconductor strain gauge.

19. The measuring device according to claim 9 or 10, wherein the sensor unit includes a capacitance type pressure sensor.

20. 11. The measuring device according to claim 9, wherein the sensor unit includes an optical fiber strain gauge.

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