JP6150331B2 - Tongue measuring device - Google Patents

Description

  The present invention relates to a tongue measuring apparatus for measuring the motor function of a tongue.

  In recent years, it has been elucidated that, in the oral cavity, pharynx, esophagus, and the like, sarcopenia, which is a phenomenon in which muscle mass decreases with age, occurs and the motor function of the oral cavity decreases. In particular, the movement of the tongue is deeply involved in the eating and swallowing functions, and it is considered that the tongue pressure is important for the formation of the bolus and the feeding into the pharynx. Therefore, it is desired to measure and evaluate oral functions including these feeding / swallowing functions.

  As a method for evaluating the oral function, for example, there is a swallowing evaluation method using spectrum analysis based on myoelectric potential (for example, Patent Document 1). In the technique disclosed in Patent Document 1, swallowing is evaluated by measuring waveform data of the surface myoelectric potential of the human pharynx and performing spectrum analysis when swallowing food and drink.

Japanese Patent No. 4702860

  However, since the technique disclosed in Patent Document 1 evaluates whether or not swallowing is normal in a state where food is actually eaten, the swallowing ability cannot be evaluated in a short time, and the inspection method As inappropriate.

  In view of the above circumstances, the present invention can stably obtain a predetermined measurement accuracy without requiring a complicated operation such as causing the user to actually move the tongue and simplify the movement function of the tongue. The purpose is to solve the problem of evaluation.

  Means employed by the present invention to solve the above problems will be described below. In order to facilitate understanding of the present invention, reference numerals in the drawings will be appended in parentheses for convenience in the following, but the present invention is not intended to be limited to the illustrated forms.

Tongue measuring apparatus according to the present invention, a pair of current application electrodes (current supply electrode 12a and 12b shown in FIG. 1) and a pair of voltage measuring electrodes (voltage detection electrode shown in FIG. 1 for use in contact with the tongue 12c and 12d) (probe 10 shown in FIG. 1), a current generator (current generator 24 shown in FIG. 4) that outputs an alternating current to the pair of current application electrodes, and the pair of voltage measurements A voltage measuring unit (voltage measuring unit 23 shown in FIG. 4) that measures the voltage of the electrode for use, and an impedance calculating unit that calculates the impedance of the tongue based on the alternating current and the voltage measured by the voltage measuring unit (FIG. 4), a storage unit (memory 25 shown in FIG. 4) that stores the relationship between the impedance of the tongue and an index that indicates the ability to move the tongue, and the relationship stored in the storage unit. , And a index generator for generating an index indicating the ability to move the tongue corresponding to the impedance of the tongue, which is calculated by the impedance calculation unit (index generation unit 32 shown in FIG. 4).

Here, the “index indicating the ability to move the tongue” includes the number of times that the saliva can be swallowed in a certain time, the number of times that a plosive sound such as “pa”, “ta”, and “ka” can be pronounced in a certain time in addition to the tongue pressure included. However, biological information obtained as a result of moving the tongue is not included. For example, the amount of saliva secreted into the oral cavity is not included in the “index indicating the ability to move the tongue”.
Further, the “relation between the impedance of the tongue and the index indicating the ability to move the tongue” may directly connect the impedance of the tongue and the index indicating the ability to move the tongue, or indirectly. It may be tied. Further, the relationship described above may be a regression equation, or may be a table in which the impedance of the tongue and an index indicating the ability to move the tongue are associated and stored.

In the tongue measuring apparatus described above, the storage unit has a first relationship that associates the impedance of the tongue with the muscle cross-sectional area of the tongue as a relationship between the impedance of the tongue and an index indicating the ability to move the tongue, A second relationship that associates a muscle cross-sectional area with an index indicating the ability to move the tongue is stored, and the index generation unit uses the first relationship stored in the storage unit to store the impedance Generating a muscle cross-sectional area of the tongue corresponding to the impedance of the tongue calculated by the calculation unit, and using the second relationship stored in the storage unit, the tongue corresponding to the muscle cross-sectional area of the tongue Preferably, an index indicating the ability to move the is generated.
According to this aspect, instead of obtaining an index indicating the ability to move the tongue directly from the impedance of the tongue, first, a muscle cross-sectional area of the tongue is generated from the impedance of the tongue using the first relationship, Using the second relationship, an index is generated that indicates the ability to move the tongue from the muscle cross-sectional area of the tongue. Therefore, the muscle cross-sectional area of the tongue can be obtained in the process of generating the index indicating the ability to move the tongue, and the muscle cross-sectional area of the tongue can be used to know the health condition of the user.

As a preferred aspect of the tongue measuring device according to the present invention, the pair of current application electrodes and the pair of voltage measurement electrodes are provided, and a groove (groove shown in FIG. 1) is provided at the base side of the probe. 13a, 13b, and 13c) may be formed. In this case, the position of the pair of current application electrodes and the pair of voltage measurement electrodes in contact with the tongue is fixed when the user bites the groove formed on the base side of the probe with teeth. It is possible to prevent variations in the measured value caused by the position shift.

Moreover, as a preferable aspect of the tongue measuring device according to the present invention, a plurality of grooves may be formed on the base side of the probe. The user fixes the position of the probe on the tongue by biting the groove. According to the present invention, since the probe is provided with a plurality of grooves, the depth at which the probe is inserted into the oral cavity differs depending on which groove is bitten. Therefore, a pair of current application electrodes (current application electrodes 12a and 12b shown in FIG. 1) and a pair of voltages are brought into contact with the tongue by biting different groove grooves (grooves 13a, 13b, or 13c shown in FIG. 1). Since the positions of the measurement electrodes (voltage measurement electrodes 12c and 12d shown in FIG. 1) can be changed, for example, the ability to move the tongue in each part such as the tip, center, or back of the tongue can be measured.

As a preferred embodiment of the tongue measuring device according to the present invention, a plurality of position detection sensors (position detection sensors 11a, 11a shown in FIG. 1) provided corresponding to each of the plurality of grooves and detecting a groove bited by a user. 11b and 11c), a position specifying unit (position specifying unit 33 shown in FIG. 4) for specifying the measurement position of the tongue for measuring the impedance of the tongue based on the output signals of the plurality of position detection sensors, It can also be set as the aspect provided with the measurement result memory | storage part (history table TBL shown in FIG. 5) which matches and memorize | stores the measurement position of the said tongue specified with the position specific part, and the said parameter | index.
According to the present invention, which groove the user has bitten with the front teeth can be specified based on the output signal of the position detection sensor, so that the measurement position of the tongue for measuring the impedance of the tongue and the index can be stored in association with each other. Therefore, the ability to move the tongue in each part of the tongue can be analyzed for detailed evaluation. As the position detection sensor, any sensor may be used as long as it detects a groove bited by the user, and the detection method is not limited. For example, a pressure sensor that detects pressure or a contact sensor that detects contact can be used as the position detection sensor, and the detection method includes a mechanical displacement method, a resistance change method, a capacitance change method, a charge change method, An optical method, a reflectance change method, a piezoresistive effect method, or a magnetic change method is included.

As a preferred aspect of the tongue measuring apparatus according to the present invention, the pair of current application electrodes and the pair of voltage measurement electrodes may be formed on one surface of the probe. In this case, for example, when a pair of current application electrodes and a pair of voltage measurement electrodes are provided only on the lower surface side of the probe, a pair of current application electrodes and a pair of voltages are provided on the palate (upper jaw). Since contact with the measurement electrode can be prevented, measurement accuracy can be improved.

It is a figure which shows the external appearance of the tongue measuring apparatus which concerns on embodiment of this invention. It is a perspective view which shows the external appearance of the probe used for the apparatus. It is explanatory drawing which shows the relationship between the groove | channel of the probe and a measurement position. It is a block diagram which shows the detailed structure of the tongue measuring apparatus which concerns on the same embodiment. It is a figure which shows the data accumulate | stored in the log | history table which concerns on the embodiment. It is a figure which shows the equivalent circuit of the structure | tissue of a tongue. It is a figure which shows the waveform change of an alternating current and a measurement voltage. It is a figure showing the relationship between the resistance component and reactance component of an impedance to a coordinate. (A) is a figure which shows a user's oral cavity from a side surface, The figure (b) is a model figure for demonstrating the relationship between an impedance and a cross-sectional area in case a tongue is a cylinder. It is a correlation diagram which shows the relationship between the impedance measured by the method of this embodiment, and the muscle cross-sectional area of the tongue measured by MRI. It is a correlation diagram which shows the relationship between the muscle cross-sectional area of the tongue estimated by the method of this embodiment, and tongue pressure. It is explanatory drawing which shows the structure | tissue of a tongue. It is a schematic diagram which shows a mode when an alternating current flows through a tongue, and explanatory drawing which shows the phase angle. It is a figure which shows the equivalent circuit of the muscle layer and fat layer of a tongue. It is a correlation diagram which shows the relationship between R / X calculated by the method of embodiment, and the fat cross-sectional area measured by MRI. It is a flowchart which shows operation | movement of a tongue measuring apparatus. It is a correlation diagram which shows the relationship between the impedance measured by the method of this embodiment, and the tongue pressure measured by MRI. (A) And (b) is a side view which shows arrangement | positioning of the groove | channel of the probe which concerns on the modification of this invention. It is a side view which shows arrangement | positioning of the electrode of the probe which concerns on the example of a change of this invention. (A) thru | or (d) is sectional drawing which shows the cross-sectional shape of a probe to the modification of this invention.

<A: Configuration>
Embodiments of a tongue measuring device according to the present invention will be described below in detail with reference to the accompanying drawings. In the present embodiment, tongue pressure will be described as an example of an index indicating the motor function of the tongue. FIG. 1 is a view showing an appearance of the tongue measuring apparatus 100 according to the present embodiment, and FIG. 2 is a perspective view of the probe.

  As shown in FIG. 1, the tongue measuring apparatus 100 includes a probe 10 and a main body 20. The probe 10 is attached to the main body 20, and electrodes (12 a, 12 b, 12 c, and 12 d) for measuring the tongue pressure, the fat cross-sectional area of the tongue, and the like are brought into contact with the tongue on the front surface of the probe 10. Is provided over the entire circumference of the probe.

  Specifically, a first current application electrode 12a, a second current application electrode 12b, a first voltage measurement electrode 12c, and a second voltage measurement electrode 12d are provided on the distal end side of the probe 10. ing. The first current application electrode 12a and the second current application electrode 12b are disposed outside the first voltage measurement electrode 12c and the second voltage measurement electrode 12d. In these electrodes (12a, 12b, 12c, and 12d), the distance d between adjacent electrodes is set to 2 mm to 20 mm.

  A plurality of grooves (13a, 13b, and 13c) are formed on the base side of the probe 10. These grooves (13a, 13b, and 13c) are provided on the upper surface and the lower surface of the probe 10, respectively. Each of the plurality of grooves (13a, 13b, and 13c) is provided with a position detection sensor (11a, 11b, or 11c) that detects the groove that the user has bitten, and the upper front teeth and the lower teeth When the front tooth bites the groove, the bited groove (13a, 13b, or 13c) is specified. As the position detection sensors (11a, 11b, and 11c), for example, a pressure sensor that detects pressure or a contact sensor that detects contact can be used. As a detection method, a mechanical displacement method, a resistance change method, an electrostatic method, or the like can be used. A capacitance change method, a charge change method, an optical method, a reflectance change method, a piezoresistive effect method, or a magnetic change method are included.

  FIG. 3 schematically shows the relationship between each part of the tongue to be measured and the groove bited by the user. The depth of the probe 10 inserted into the oral cavity varies depending on which groove the user bites with the upper front teeth and the lower front teeth. When the user bites the groove 13c closest to the root of the probe 10, the output signal of the position detection sensor 11c becomes active. In this case, the probe 10 is inserted deeply into the oral cavity. For this reason, the back of the tongue is the measurement position. When the user bites the groove 13b that is second closest to the base of the probe 10, the output signal of the position detection sensor 11b becomes active. In this case, the central part of the tongue is the measurement position. Further, when the user bites the groove 13a farthest from the base of the probe 10, the output signal of the position detection sensor 11a becomes active. In this case, since the probe 10 is inserted shallowly into the oral cavity, the tip of the tongue is the measurement position.

  The main body 20 includes a display unit 22 and input units (21a, 21b) on the appearance. The input unit (21a, 21b) includes a measurement key 21a and a power key 21b. The measurement key 21a is used by the user to instruct measurement start and display of the history of past measurement results, and the power key 21b is used to start power supply to the main body 20 for a series of measurements. Used. The display unit 22 displays the current measurement result and the past measurement result.

  FIG. 4 is a block diagram showing a detailed configuration of the tongue measuring apparatus 100 according to the present embodiment. As shown in FIG. 2, the main body 20 includes a current generation unit 24, a voltage measurement unit 23, a power supply unit 25, a memory 26, and a CPU 30 in addition to the display unit 22 and the input unit 21 described above.

  The current generator 24 causes an alternating current to flow from the first current application electrode 12a and the second current application electrode 12b to the tissue of the tongue while the probe 10 is inserted into the oral cavity and pressed against the tongue. . In the present embodiment, the frequency of the alternating current output from the current generator 24 is set to 50 kHz. However, the frequency of the alternating current may be 5 kHz to 500 kHz that allows the alternating current to flow through the tissue inside the tongue. In particular, a frequency exceeding 40 kHz is preferable from the viewpoint of efficiently supplying an alternating current to the tissue inside the tongue. The voltage measurement unit 23 measures the voltage between the first voltage measurement electrode 12c and the second voltage measurement electrode 12d.

  The power supply unit 25 supplies power to each part of the electric system of the main body 20. The memory 26 functions as a work area for the CPU 30, and evaluates various arithmetic expressions for calculating the muscle sectional area, tongue pressure, tongue fat sectional area, and the like of the user's tongue and the ability to move the tongue. A history table TBL that stores an evaluation reference level used in the above, a history of measurement results, and the like are stored.

As shown in FIG. 5, this history table TBL includes tongue pressure (kPa) according to tongue measurement position (tip, center, back), tongue muscle cross-sectional area (mm ² ), tongue fatness. The area (mm ² ), tongue pressure, and evaluation level (for example, three levels of a healthy level, an intervention level, and a care level) are recorded.

  The CPU 30 is means for executing various control processes. The CPU 30 functions as an impedance calculation unit 31, an index generation unit 32, and a position specification unit 33 by executing a predetermined program. The impedance calculation unit 31 calculates the impedance of the tongue based on the alternating current output from the current generation unit 24 and the voltage measured by the voltage measurement unit 23.

  The index generation unit 32 generates an index indicating the ability to move the tongue based on the impedance of the tongue calculated by the impedance calculation unit 31. The position specifying unit 33 specifies a measurement position for measuring the impedance of the tongue based on the output signal output from the position detection sensors (11a, 11b, and 11c).

<B: Measurement principle>
The tongue measuring device of this embodiment can measure the motor function of the tongue, such as measuring the muscle cross-sectional area of the tongue, determining the tongue pressure level, and measuring the fat cross-sectional area of the tongue. Hereinafter, a method for measuring the motor function of the tongue in the present embodiment will be described.

(1) Measurement of tongue impedance First, the measurement principle of tongue impedance will be described. FIG. 6 is a diagram showing an equivalent circuit of a human tissue, FIG. 7 is a diagram showing a waveform change between an alternating current and a measured voltage, and FIG. 8 is a relationship between a resistance component and a reactance component of a tongue impedance. FIG.

  Usually, the impedance of the tongue is represented by an equivalent circuit with a lumped constant composed of an extracellular fluid resistance Re, an intracellular fluid resistance Ri, and a cell membrane capacitance Cm as shown in FIG. Therefore, when an alternating current flows through the tongue, the measured voltage to be measured is out of phase with the alternating current i (t) as shown in FIG.

The impedance calculation unit 31 performs sampling processing on the analog signal related to such a measurement voltage, and converts this into a digital signal. Then, the impedance of the tongue, or parameters such as absolute value, phase difference, resistance component value, and capacitance component value based on the impedance are obtained through DFT (Discrete Fourier Transformation) processing on this digital signal. In the present embodiment, the DFT process is performed using the input current i (t) and the output voltage V _HUM , so that the capacitance component of the tongue impedance (hereinafter referred to as reactance X) and the resistance component of the tongue impedance (hereinafter referred to as “reactance X”). Hereinafter, it is referred to as resistance R).

また、測定されたインピーダンスベクトルは、横軸をレジスタンスＲ、縦軸をリアクタンスＸにとる平面にプロットしていくと、そのベクトル軌跡は図８に示す円弧状の軌跡となる。この図８において、Ｚは舌のインピーダンスを示し、座標交点は零地点を示し、偏角φは位相差を示している。 Specifically, the reactance X and the resistance R are obtained from the relationship shown in FIG.

Further, when the measured impedance vector is plotted on a plane having resistance R on the horizontal axis and reactance X on the vertical axis, the vector locus becomes an arc-shaped locus shown in FIG. In FIG. 8, Z represents the impedance of the tongue, the coordinate intersection represents the zero point, and the declination φ represents the phase difference.

インピーダンス算出部３１は、式（１）及び式（２）を演算することによって、交流電流及び測定電圧から舌のインピーダンスＺ、位相差φ、リアクタンスＸ及びレジスタンスＲを算出することができる。 Therefore, the impedance Z and the phase difference φ of the tongue are obtained by the following equations (1) and (2) using the reactance X and the resistance R, respectively.

The impedance calculation unit 31 can calculate the impedance Z, the phase difference φ, the reactance X, and the resistance R of the tongue from the alternating current and the measured voltage by calculating the expressions (1) and (2).

(2) Estimation of tongue muscle cross-sectional area Next, estimation of tongue muscle cross-sectional area will be described. FIG. 9A is a diagram showing the inside of the oral cavity 40 of the user from the side, and FIG. 9B illustrates the relationship between the impedance of the tongue and the muscle cross-sectional area of the tongue when the tongue 41 is a cylinder. It is a model figure for doing.

ここで、ρは物質固有の値であるため、一定値とみなすことができる。また、プローブ１０に設けられた電極間距離は一定のため、Ｌは一定値となる。したがって、舌の筋肉断面積Ａは、舌のインピーダンスＺに反比例することとなる。 The tongue 41 in the oral cavity 40 as shown in FIG. 9 (a) is a mixture of fat and muscle, but as shown in FIG. 9 (b), the fat is divided into the outside and the muscle inside. Replace with a column. Since fat contains almost no electrolyte, it can be assumed to be an insulator. On the other hand, since muscle contains a lot of electrolyte, it can be assumed as a conductor. For the tongue, if the length for measuring the muscle (conductor) is L, the muscle cross-sectional area of the tongue is A, the muscle resistance value of the tongue is ρ, and the impedance of the tongue is Z, the muscle cross-sectional area A of the tongue is The following equation (3) is obtained.

Here, since ρ is a value unique to the substance, it can be regarded as a constant value. Further, since the distance between the electrodes provided in the probe 10 is constant, L is a constant value. Accordingly, the muscle cross-sectional area A of the tongue is inversely proportional to the impedance Z of the tongue.

  Thus, there is a certain relationship between the muscle cross-sectional area of the tongue and the impedance of the tongue. However, the muscle resistance value ρ of the tongue varies depending on the subject. Therefore, the applicant measured the impedance of the tongue and the muscle cross-sectional area of the tongue using MRI (Magnetic Resonance Imaging system) for many users. Next, the measurement result was subjected to regression analysis to obtain a regression equation representing the relationship between tongue impedance and muscle cross-sectional area ratio.

但し、ａ及びｂは定数である。 FIG. 10 is a correlation diagram showing the relationship between tongue impedance and tongue muscle cross-sectional area for a large number of users. Here, assuming that the muscle cross-sectional area of the tongue is Sm and the impedance of the tongue is Z, a regression equation showing the relationship between them is expressed by the following equation (4).

However, a and b are constants.

  In the example shown in FIG. 10, a high correlation of r = 0.82 is obtained between the tongue impedance and the tongue muscle cross-sectional area measured by MRI. Therefore, according to the estimation method using the regression equation (4), it is possible to estimate the muscle cross-sectional area of the tongue with high accuracy by using the impedance value of the tongue as a parameter. The memory 26 stores the regression equation (4). The index generation unit 32 reads the regression equation (4) stored in the memory 26 and substitutes the impedance of the tongue obtained by the measurement into the regression equation (4) to generate the tongue muscle cross-sectional area.

但し、ｃ及びｄは定数である。回帰式（５）を用いた推定方法によれば、舌の筋肉断面積の値をパラメータとして用いることにより舌圧を高い精度で推定することができる。指標生成部３２は、先に推定した舌の筋肉断面積Ｓｍをメモリ２６に保存されている回帰式（５）に代入することで、舌圧Ｔpの値を求める。 (3) Estimation of tongue pressure Next, estimation of tongue pressure will be described. Applicants have measured the tongue muscle cross section using MRI and tongue pressure using a tongue pressure measuring instrument for a number of users. This tongue pressure measuring instrument sandwiches a small balloon between the tongue and the maxilla palate, and pushes the small balloon to the full force with the tongue, so that the air pressure is detected and converted into an electrical signal by the converter connected to the small balloon. The pressure is measured.
FIG. 11 is a correlation diagram between the lingual muscle cross-sectional area and the tongue pressure obtained by the above measurement, and there is a high correlation between the two, that is, a correlation coefficient r = 0.69. This measurement result was subjected to regression analysis to obtain a regression equation representing the relationship between tongue impedance and muscle cross-sectional area ratio. When the tongue pressure is Tp, the regression equation is given by the following equation (5).

However, c and d are constants. According to the estimation method using the regression equation (5), the tongue pressure can be estimated with high accuracy by using the value of the muscle cross-sectional area of the tongue as a parameter. The index generation unit 32 obtains the value of the tongue pressure Tp by substituting the previously estimated tongue muscle cross-sectional area Sm into the regression equation (5) stored in the memory 26.

(4) Determination of evaluation level of ability to move tongue Next, the index generation unit 32 determines an evaluation level of ability to move the tongue based on tongue pressure. Specifically, the index generation unit 32 determines the evaluation level of the ability to move the tongue by comparing the value of the tongue pressure estimated by the method of the present embodiment with the evaluation reference level stored in the memory 26. In the present embodiment, the determination is performed in three stages of “healthy level”, “intervention level required”, and “care level required”. The evaluation reference level is determined based on the average value Av and the standard deviation SD, which are calculated in advance from the average value Av and standard deviation SD of the tongue pressure measured for a large number of subjects. In this embodiment, four evaluation reference levels Ra1, Ra2, Rb1, and Rb2 are set as follows.
Rb2 = Av-2SD <Rb1 = Av-SD <Ra1 = Av + SD <Ra2 = Av + 2SD
Specifically, the index generation unit 32 determines as follows.
If Rb1 ≦ estimated tongue pressure <Ra1, “healthy level”
When Rb2 ≦ estimated tongue pressure <Rb1 or Ra1 ≦ estimated tongue pressure <Ra2, “intervention level required”
If the estimated tongue pressure <Rb2 or Ra2 ≦ estimated tongue pressure, the level of care required
For example, if the average value Av is 47.3 kPa and the standard deviation SD is 2.6 kPa,
Rb2 = 42.1 kPa, Rb1 = 44.7 kPa, Ra1 = 49.9 kPa, Ra2 = 52.5 kpa. The evaluation reference levels Ra1, Ra2, Rb1, and Rb2 are stored in the memory 26.

(5) Estimation of the fat cross-sectional area of the tongue Next, the calculation of the fat cross-sectional area of the tongue will be described. Here, first, the phase difference between the AC current generated when the AC current output from the current generator 24 flows through the muscle portion of the tongue and the voltage measured by the voltage measurement unit 23, and the current output from the current generator 24. The difference between the alternating current generated when the alternating current flows through the fat portion of the tongue and the phase difference between the voltage measured by the voltage measuring unit 23 will be described in detail. FIG. 12 is a schematic illustration of the tissue of the tongue.

  As shown in FIG. 12, the tongue tissue (muscle tissue and adipose tissue) has a plurality of cell membranes 52 each containing an intracellular fluid 50 and an extracellular fluid 54 interposed between the cell membranes 52. The muscular tissue of the tongue and the fatty tissue of the tongue are represented by an equivalent circuit composed of the extracellular fluid resistance Re, the intracellular fluid resistance Ri, and the cell membrane capacitance Cm as shown in FIG.

  In the adipose tissue of the tongue, since the intracellular fluid 50 is hardly contained in the cell membrane 52, the value of the resistance Ri of the intracellular fluid 50 is much larger than the value of the resistance Re of the extracellular fluid 54. (Re <Ri). For this reason, when the alternating current output from the current generator 24 flows through the adipose tissue of the tongue, most of the current flows through the resistance component Re of the extracellular fluid. There is almost no phase difference from the applied voltage.

  On the other hand, in the muscular tissue, since the intracellular fluid 50 is contained in the cell membrane 52, when the alternating current output from the current generator 24 flows through the muscular tissue of the tongue, the alternating current is the resistance of the extracellular fluid. Not only the component Re but also the capacitive component Cm of the cell membrane 52 and the resistance component Ri of the intracellular fluid 50 flow. Therefore, a phase difference is generated between the AC current output from the current generator 24 and the voltage measured by the voltage measuring unit 23 due to the influence of the capacitance component Cm. That is, while the muscle portion has the property of easily causing a phase difference, the fat portion has the property of hardly causing a phase difference. Therefore, as the amount of fat on the tongue increases, the property of the fat portion becomes dominant. The phase difference is reduced. On the other hand, the smaller the amount of fat on the tongue, the more dominant the properties of the muscle portion and the greater the phase difference. In the present embodiment, the fat cross-sectional area is estimated using this fact.

  More specifically, it is as follows. The impedance calculation unit 31 includes an alternating current output from the current generation unit 24 and a voltage measured by the voltage measurement unit 23 when the electrodes (12a, 12b, 12c, and 12d) are in contact with the tongue. A resistance R that is a real part of the impedance of the tongue and a reactance X that is an imaginary part of the impedance of the tongue are obtained, and then R / X that is a ratio of the reactance X and the resistance R is obtained. The smaller the phase difference, the smaller the ratio of reactance X to resistance R, while the larger the phase difference, the larger the ratio of reactance X to resistance R. Then, the impedance calculation unit 31 determines the fat cross-sectional area of the tongue corresponding to the obtained R / X value.

  Here, the relationship between the above R / X and the fat cross-sectional area of the tongue will be described. FIG. 13 is a schematic diagram showing a state when an alternating current flows through the tongue and its phase difference. FIG. 13 (a) is a diagram showing a case where the fat mixture ratio is large, and FIG. 13 (b). These are figures which show the case where the mixture rate of fat is small. In FIG. 13, a cross section of the tongue is displayed, the white portion indicates fat, and the black portion indicates muscle. In the present embodiment, the fat amount per sectional area of the tongue is Lf. Moreover, FIG. 14 is a figure which shows the equivalent circuit of the fat part and muscle part at this time. Rf shown in FIG. 14 is a resistance component of the fat portion.

As described above, the capacity component can be almost ignored in the fat portion. Sm represents a portion corresponding to the muscle portion, Rj represents a resistance component of the extracellular fluid 54 in the muscle portion, Rk represents a resistance component of the intracellular fluid 50 in the muscle portion, and Cl represents a cell membrane 52 in the muscle portion. The capacity component of is shown. At this time, R / X, which is the ratio of reactance X and resistance R at the tongue in contact with the electrode, is expressed by the following equation (6).

上記式（７）においてｋは定数である。
上述の式（６）及び式（７）から、脂肪量Ｌｆは以下の式（８）で表される。

Further, since the resistance component Rf of the fat portion is inversely proportional to the fat amount Lf, the relationship between the two is expressed by the following equation (7).

In the above formula (7), k is a constant.
From the above formulas (6) and (7), the fat mass Lf is expressed by the following formula (8).

但し、ｈ及びｉは定数である。 In the above formula (8), f and g are constants. As understood from the above formula (8), the fat amount Lf and R / X are in a proportional relationship. That is, as shown in FIG. 13 (a), as the fat amount Lf increases, the property of the fat portion becomes dominant and the phase difference decreases, so that the ratio of the reactance X to the resistance R decreases (R / X The value will increase). On the other hand, as shown in FIG. 13 (b), the smaller the fat amount Lf, the more dominant the property of the muscle portion and the larger the phase difference, so the ratio of reactance X to resistance R increases (R / X (The value becomes smaller). In the present embodiment, since the positions of the first voltage measuring electrode 12c and the second voltage measuring electrode 12d are fixed, the fat mass of the tongue is proportional to the fat cross-sectional area of the tongue. . That is, the fat cross-sectional area of the tongue is obtained by multiplying the amount of fat of the tongue given by Equation (8) by a coefficient. When the fat cross-sectional area of the tongue is Sf, reactance X, and resistance R, the fat cross-sectional area of the tongue is given by the following equation (9) with R / X as a parameter.

However, h and i are constants.

Thus, there is a certain relationship between the fat cross-sectional area of the tongue and R / X. In order to determine the constants h and i in equation (9), Applicants measured R / X and MRI for fat cross-section for many users. FIG. 15 is a correlation diagram showing the relationship between R / X and the measured value of fat cross-sectional area Sf measured by MRI. A high correlation with a correlation coefficient r = 0.92 is obtained between the R / X and the measured value of the fat cross-sectional area of the tongue measured by MRI. The applicant determined the constants h and i by regression analysis of the actual measurement values.
Expression (9) is stored in the memory 26, and the index generation unit 32 calculates R / X based on the alternating current generated by the current generation unit 24 and the voltage measured by the voltage measurement unit 23. Then, the equation (9) stored in the memory 26 is read, and the calculated fatal cross-sectional area of the tongue is generated by substituting the calculated R / X into the read equation (9).

<C: Operation of tongue measuring device>
Next, the operation of the tongue measuring apparatus 100 will be described. In this embodiment, the user holds the main body 20, bites any of the grooves (13 a, 13 b, 13 c) of the probe 10 with the front teeth, and makes the electrodes (12 a, 12 b, 12 c, and 12 d) contact the tongue. Various measurement results are displayed on the display unit 22. The specific contents will be described below with reference to FIG. FIG. 16 is a flowchart showing a specific operation of the tongue measuring apparatus 100 according to the present embodiment.

  First, when the power key 21b is turned on by the user, power supply from the power supply unit 25 is started, and the tongue measuring apparatus 100 enters the measurement mode.

  Thereafter, the tongue measuring apparatus 100 stands by until the measurement is started by the measurement key 21a by the user ("N" in step S1), and when the measurement key 21a is operated to start setting ("Y" in S1). "), The measurement position for measuring the impedance of the tongue is specified (step S2).

  Specifically, it waits until the position specifying unit 33 acquires a detection signal from any of the position detection sensors 11a to 11c (“N” in step S2). On the other hand, when the user bites the groove 13 with the user's teeth and the position specifying unit 33 acquires a detection signal from any of the position detection sensors 11a to 11c ("Y" in step S2), the impedance of the tongue The measurement position for measuring is specified.

  Then, the CPU 30 measures the muscle cross-sectional area, the fat cross-sectional area, and the evaluation level in the user's tongue while detecting the detection signal. More specifically, when the electrodes (12a, 12b, 12c, and 12d) come into contact with the user's tongue, one of the first current application electrode 12a and the second current application electrode 12b. A current path is formed from the electrode to the other electrode via the user. An alternating current output from the current generator 24 flows through the current path. Based on the alternating current flowing through the current path and the voltage measured by the voltage measurement unit 23, the impedance calculation unit 31 is connected between the first current application electrode 12a and the second current application electrode 12b. The reactance X and the resistance R are obtained at step S3 and step S4.

  Thereafter, the CPU 30 calculates the tongue impedance Z from the resistance R and the reactance X (step S5). Specifically, the CPU 30 executes the calculation of the above formula (1). After that, the CPU 30 substitutes the calculated tongue impedance Z into the equation (4) to generate the tongue muscle cross-sectional area Sm (step S6). Further, the CPU 30 generates a tongue pressure by substituting the generated muscle sectional area Sm of the tongue into the above equation (5) (step S7). Thereafter, the CPU 30 determines the evaluation level of the ability to move the tongue by comparing the generated tongue pressure with the reference evaluation levels Ra1, Ra2, Rb1, and Rb2 (step S8).

Further, the CPU 30 generates the fat cross-sectional area of the tongue from the resistance R and the reactance X based on the above formula (9) (step S9). Note that the CPU 30 may calculate the muscle ratio or fat percentage of the tongue according to the following formula from the muscle cross-sectional area of the tongue generated in step S6 and the fat cross-sectional area of the tongue generated in step S9.
Tongue muscle ratio = tongue muscle cross-sectional area / (tongue muscle cross-sectional area + tongue fat cross-sectional area)
Tongue fat percentage = tongue fat cross-sectional area / (tongue muscle cross-sectional area + tongue fat cross-sectional area)

Then, the CPU 30 controls the display unit 22 to display various results (tongue pressure value, tongue muscle cross-sectional area, tongue fat cross-sectional area, and evaluation level) obtained as described above (step S10). . Then, the result information is recorded in the history table together with the measurement position (step S11). For example, the measurement date and time is 14:30 on March 1, 2013, the user measures the groove 13b, the tongue pressure is 38 kPa, the tongue muscle cross-sectional area is 600 mm ² , and the tongue fat cross-sectional area is and it was 200mm ^2. In this case, since the position detection sensor 11b detects that the groove 13b has been gripped, the CPU 30 determines that the measurement position is the center of the tongue. Further, as shown in the above example, if the average value Av of tongue pressure is 47.3 kPa, the standard deviation SD is 2.6 kPa, and the evaluation reference level Rb2 is 42.1 kPa, the measured tongue pressure is Since 38 kPa is less than the evaluation reference level Rb2, the CPU 30 determines that the evaluation level is the “care required level”. These measurement results are recorded in a portion indicated by a thick frame in the history table TBL shown in FIG.

  As described above, in this embodiment, the index generation unit 32 calculates the impedance of the tongue from the alternating current flowing through the tongue and the voltage measured by the voltage measurement unit 23, and the muscle of the tongue from the impedance of the tongue. In addition to estimating the cross-sectional area, an evaluation level of the ability to move the tongue is generated based on the estimated muscle cross-sectional area of the tongue. Thus, according to the present embodiment, it is possible to easily estimate an index indicating the ability to move the tongue without actually moving the tongue.

  Further, according to the present embodiment, since the plurality of grooves (13a, 13b, and 13c) are formed on the base side of the probe 10, the user bites any groove of the probe 10 with teeth. Thus, since the positions of the current application electrodes 12a and 12b and the voltage measurement electrodes 12c and 12d that are in contact with the tongue are fixed, it is possible to prevent variations in measurement values caused by the deviation of the measurement position. Furthermore, since the position of the electrode which contacts a tongue can be changed because a user bites a different groove | channel (13a, 13b, 13c), the motor function in each part of a tongue can be measured.

  Furthermore, in this embodiment, a position detection sensor (11a, 11b, or 11c) is provided corresponding to each of the plurality of grooves (13a, 13b, and 13c), and the position specifying unit 33 includes the position detection sensor (11a, Based on the output signals from 11b and 11c), the measurement position for measuring the impedance of the tongue can be specified. As a result, the measurement position and the index can be associated with each other and stored in the history table TBL, the motor function in each part of the tongue can be analyzed, and detailed evaluation can be performed.

<C: Modification>
The present invention is not limited to the above-described embodiments, and for example, the following modifications are possible. Further, two or more of the following modifications or the above-described embodiments can be combined.

但し、ｅ及びｆは定数である。回帰式（１０）を用いた推定方法によれば、舌のインピーダンスの値をパラメータとして用いることにより舌圧を高い精度で推定することができる。指標生成部３２は、舌のインピーダンスをメモリ２６に保存されている回帰式（１０）に代入することで、舌圧Ｔpの値を求める。 (1) Modification 1
In the above-described embodiment, the muscle cross-sectional area of the tongue is estimated from the impedance of the tongue, and the tongue pressure is estimated based on the estimated muscle cross-sectional area of the tongue. That is, the tongue pressure is indirectly specified based on the impedance of the tongue, but the present invention is not limited to this, and it is of course possible to estimate the tongue pressure directly from the impedance of the tongue. .
Applicants have measured the tongue impedance for a number of users and measured the tongue pressure using a tongue pressure meter. This tongue pressure measuring instrument sandwiches a small balloon between the tongue and the maxilla palate, and pushes the small balloon to the full force with the tongue, so that the air pressure is detected and converted into an electrical signal by the converter connected to the small balloon. The pressure is measured.
FIG. 17 is a correlation diagram between the impedance of the tongue and the tongue pressure obtained by the above measurement, and there is a high correlation between the two, that is, a correlation coefficient r = 0.91. This measurement result was subjected to regression analysis to obtain a regression equation representing the relationship between tongue impedance and tongue pressure. When the tongue impedance is Z and the tongue pressure is Tp, the regression equation is given by the following equation (10).

However, e and f are constants. According to the estimation method using the regression equation (10), the tongue pressure can be estimated with high accuracy by using the value of the impedance of the tongue as a parameter. The index generation unit 32 obtains the value of the tongue pressure Tp by substituting the impedance of the tongue into the regression equation (10) stored in the memory 26.

(2) Modification 2
In the above-described embodiment, tongue pressure is exemplified as an index indicating the ability to move the tongue. However, the present invention is not limited to this, and any index can be calculated as long as it indicates a function of moving the tongue. May be. For example, it may be the number of times that the saliva can be swallowed in a certain time, or the number of times that a plosive sound such as “pa”, “ta”, and “ka” can be pronounced in a certain time. In the operation to swallow the saliva, it is necessary to move the muscle of the tongue and send the saliva to the throat, the function of moving the tongue is demonstrated, and in order to pronounce the plosive, it is necessary to move the tongue by contacting the upper jaw, Since the function of moving the tongue is exhibited, these times can be used as an index indicating the ability to move the tongue. In addition, you may evaluate as a motor function of the whole tongue combining these tongue pressure, the frequency | count which can swallow a saliva, and the frequency | count which can sound a plosive.

  Here, as a method of acquiring the number of times that the saliva is swallowed or the number of pronunciations, a numerical value separately counted by the user may be input using an input key. In this case, the tongue measuring device 100 may be provided with a stopwatch function and a counter function, and an interface for simply inputting the number of times per unit time may be provided in the main body. Furthermore, regarding the number of sound generations, for example, a sound sensor may be provided in the main body, and the number of sound generations may be counted by recognizing a plosive sound per unit time.

  When the number of times that the saliva is swallowed is used as an indicator of the ability to move the tongue, the impedance of the tongue and the number of times that the saliva can be swallowed for a certain period of time are measured for a large number of users, and the results are subjected to multiple regression analysis and the impedance of the tongue A regression equation is obtained in advance using as a variable. Then, the CPU 30 may calculate the number of times that saliva can be swallowed in a certain period of time by substituting the tongue impedance into the regression equation.

  In addition, when the number of times that a plosive can be pronounced is used as an indicator of the ability to move the tongue, the impedance of the tongue and the number of times that a plosive can be pronounced are measured for many users, and the measurement results are subjected to multiple regression analysis. A regression equation using the tongue impedance as a variable is obtained in advance. Then, the CPU 30 may calculate the number of times that the plosive can be pronounced in a certain period of time by substituting the tongue impedance into the regression equation.

(3) Modification 3
In the above-described embodiment, the first current application electrode 12a and the second current application electrode 12b are sandwiched between the first voltage measurement electrode 12c and the second voltage measurement electrode 12d. However, the present invention is not limited to this. For example, the first voltage measuring electrode 12c and the second voltage measuring electrode 12d are connected to the first current applying electrode 12a and the second current measuring electrode 12a. It is also possible to adopt a mode of being sandwiched between the current application electrode 12b.

(4) Modification 4
In the above-mentioned embodiment, although the some groove | channel (13a, 13b, and 13c) is provided up and down and is arrange | positioned so that a user may bite with an upper front tooth and a lower front tooth, this is illustrated. For example, as shown in FIG. 18 (a), grooves (14a, 14b, and 14c) can be provided only on the lower surface, and as shown in FIG. 18 (b), It is also possible to adopt a mode in which grooves (15a, 15b, and 15c) are provided only on the upper surface.

(5) Modification 5
In the above-described embodiment, the electrodes (12a, 12b, 12c, and 12d) are exemplified to be provided over the entire circumference of the probe. However, the present invention is not limited to this. For example, as shown in FIG. It is also possible to adopt a mode in which a pair of current application electrodes 16a and 16b and a pair of voltage measurement electrodes 16c and 16d are provided on the contacting lower surface. In this case, since the pair of current application electrodes 16a and 16b and the pair of voltage measurement electrodes 16c and 16d can be prevented from coming into contact with the palate, the measurement accuracy can be improved.

(6) Modification 6
In the above-described embodiment, the cross-sectional shape of the probe 10 has been described as a rectangle as shown in FIG. 2, but the present invention is not limited to this. For example, as shown in FIG.
It may be a triangle as shown in FIG. 20 (b), a circle as shown in FIG. 20 (c), or an ellipse as shown in FIG. 20 (d).

(7) Modification 7
In the above-described embodiment, the cross-sectional shape of the probe 10 has been described as a rectangle as shown in FIG. 2, but the present invention is not limited to this. For example, as shown in FIG.
It may be a triangle as shown in FIG. 20 (b), a circle as shown in FIG. 20 (c), or an ellipse as shown in FIG. 20 (d).

(8) Modification 8
In the above-described embodiment, the regression equation that associates the impedance of the tongue with the muscle cross-sectional area of the tongue and the tongue pressure that is an example of an index indicating the ability to move the tongue are associated with the memory 26. The regression equation is stored, and the CPU 30 reads these regression equations and generates tongue pressure based on the impedance of the tongue. However, the present invention is not limited to this, and the impedance of the tongue is stored in the memory 26. And a table that associates tongue impedance and tongue muscle cross-sectional area with each other, and a table that associates tongue muscle cross-sectional area with an index that indicates the ability to move the tongue. The CPU 30 may generate tongue pressure from the impedance of the tongue with reference to these tables. The same applies to the first modification, and a table that associates tongue impedance and tongue pressure is stored in the memory 26, and the CPU 30 refers to this table to calculate the tongue pressure from the impedance of the tongue. It may be generated.
The point is that the memory 26 stores the relationship between the impedance of the tongue and the index indicating the ability to move the tongue, directly or indirectly, and uses the stored relationship to store the tongue based on the impedance of the tongue. An index indicating the ability to move can be generated.

(9) Modification 9
In the embodiment described above, the probe 10 is provided with a plurality of grooves 13a, 13b, and 13c so that measurement can be performed at locations such as the tip, center, and back of the tongue. However, when the distance d between the electrodes is increased. Electrodes (12a, 12b, 12c, and 12d) can be placed from the tip of the tongue to the back of the tongue (for example, close to 20 mm). In this case, when the distance between the center of a certain groove and the center of an adjacent groove is dx, an index indicating the ability to move the tongue with respect to the entire tongue can be generated by setting dx <d. Depending on the size of the tongue, it is possible to finely adjust the location where the electrodes (12a, 12b, 12c, and 12d) are brought into contact with the tongue according to the size of the tongue.

DESCRIPTION OF SYMBOLS 10 ... Probe, 11a, 11b, 11c ... Position detection sensor, 12a ... 1st current application electrode, 12b ... 2nd current application electrode, 12c ... 1st voltage measurement electrode, 12d 2nd electrode for voltage measurement, 13a, 13b, 13c ... groove, 20 ... main body, 22 ... display unit, 21 ... input unit, 23 ... voltage measurement unit, 24 ... current generation unit, 25... Power supply unit, 26... Memory, 30... CPU, 31... Impedance calculation unit, 32 .. index generation unit, 33.

Claims (6)

A probe having a pair of current application electrodes and a pair of voltage measurement electrodes used in contact with the tongue;
A current generator that outputs an alternating current to the pair of current application electrodes;
A voltage measuring unit for measuring the voltage of the pair of voltage measuring electrodes;
An impedance calculator that calculates the impedance of the tongue based on the alternating current and the voltage measured by the voltage measuring unit;
A storage unit storing a relationship between the impedance of the tongue and an index indicating the ability to move the tongue;
Using the relationship stored in the storage unit, an index generation unit that generates an index indicating the ability to move the tongue corresponding to the impedance of the tongue calculated by the impedance calculation unit;
A tongue measuring device comprising: In the memory unit, as a relationship between the impedance of the tongue and an index indicating the ability to move the tongue, a first relationship that associates the impedance of the tongue and the muscle cross-sectional area of the tongue, and the muscle cross-sectional area of the tongue and the tongue are moved. And a second relationship that associates an index indicating ability,
The index generation unit generates a muscle cross-sectional area of the tongue corresponding to the impedance of the tongue calculated by the impedance calculation unit using the first relation stored in the storage unit, and the storage unit Generating an indication of the ability to move the tongue corresponding to the muscle cross-sectional area of the tongue using the second relationship stored in
The tongue measuring apparatus according to claim 1. The pair of current application electrodes and the pair of voltage measurement electrodes are provided on the tip side of the probe,
A groove is formed on the base side of the probe,
The tongue measuring apparatus according to claim 1 or 2, wherein   The tongue measuring apparatus according to claim 3, wherein a plurality of the grooves are formed on a base side of the probe. A plurality of position detection sensors provided corresponding to each of the plurality of grooves and detecting a groove bited by a user;
A position specifying unit for specifying a measurement position of the tongue for measuring impedance of the tongue based on output signals of the plurality of position detection sensors;
A measurement result storage unit that associates and stores the measurement position of the tongue specified by the position specifying unit and the index;
The tongue measuring device according to claim 4 provided with. The tongue measuring apparatus according to claim 1, wherein the pair of current application electrodes and the pair of voltage measurement electrodes are formed on one surface of the probe.

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