Massage device

Abstract

This massaging device comprises a plurality of pushing parts for pushing on a person massaged, and an intravital measurement part for measuring a change in biological information for the person massaged in response to the pushing. The intravital measurement part comprises one or more sensors for electrical impedance tomography. The sensor for electrical impedance tomography comprises four or more electrodes.

Description

Technical Field

[0001] The present invention relates to a massage device. This application claims priority based on Japanese Patent Application No. 2021-174582 filed in Japan on October 26, 2021, and incorporates its content herein.

Background Art

[0002] When maintaining a standing position for a long time, the interstitial fluid of the calf muscles or fat accumulates due to gravity, causing swelling. This results in a feeling of fatigue. In addition, in the case of lymphedema as a cancer sequela, due to the retention of lymph fluid, interstitial fluid accumulates, causing swelling. Therefore, there is a need for a technique to effectively reflux interstitial fluid and lymph fluid.

[0003] Massage applies external pressure to the subject using a rolling ball, an airbag, etc. By this, in addition to being able to loosen the muscles and fat of the subject, it is possible to circulate the interstitial fluid, lymph fluid, and venous blood in the muscles or fat.

[0004] For example, in the massage of the limbs, by using intermittent pneumatic compression (IPC), it is possible to effectively circulate the interstitial fluid, lymph fluid, and venous blood.

[0005] Intermittent pneumatic compression is achieved by covering with a sleeve (bag) composed of multiple compartments (chambers) and adjusting the air pressure within each compartment both temporally and spatially in a state adapted to the curved surfaces of the limbs. For example, Patent Document 1 discloses an air massager characterized by including a plurality of air bags wound around an object to be acted upon, a plurality of switching valve devices for individually supplying and discharging air to and from these air bags via air supply pipes, an air pressure source device connected to the switching valve devices, a pressure sensor attached to the air supply pipes, a detection means for detecting an abnormality by detecting the state of pressure change by the pressure sensor during operation, an alarm means for issuing an alarm when an abnormality is detected by the detection means, and a timing display means for measuring and displaying the elapsed time starting from the occurrence of the abnormality.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The circulation of interstitial fluid, lymphatic fluid, and venous blood due to massage varies greatly among individuals and, particularly for patients with lymphedema, also shows significant daily fluctuations. With the air massager of Patent Document 1, the subject being treated cannot determine whether interstitial fluid, lymphatic fluid, and venous blood have circulated sufficiently due to the massage. As a result, the massage may be terminated midway.

[0008] The present invention has been made in view of the above circumstances, and an object thereof is to provide a massage device capable of measuring changes in the distribution of interstitial fluid, lymphatic fluid, and venous blood in the living body due to massage.

Means for Solving the Problems

[0009] To solve the above problems, the present invention proposes the following means. <1> A massage device according to an aspect of the present invention includes a plurality of pressing parts that press on a subject, and a living body measurement part that measures changes in the biological information of the subject due to the pressing. Jacobian matrix calculation unit, electrical property distribution calculation unit, and pressing control unit The living body measurement part includes two or more electrical impedance tomography sensors, and the electrical impedance tomography sensors include four or more electrodes. At least one of the plurality of pressing parts is provided between the electrical impedance tomography sensors. The living body measurement part measures changes in the distribution of interstitial fluid, lymphatic fluid, and venous blood. The electrical impedance tomography sensors are arranged near the pressing parts. 、 The in-vivo measurement unit applies a current or a potential difference between the electrodes. When applying the current, it measures the potential difference and phase based on a current application voltage measurement pattern. When applying the potential difference between the electrodes, it measures the current and phase based on a voltage application current measurement pattern. The Jacobian matrix calculation unit calculates the Jacobian matrix of the subject based on a predetermined current application voltage measurement pattern or voltage application current measurement pattern, mesh coordinates obtained by dividing the contour of the subject, and the coordinates of each of the electrodes. The electrical property distribution calculation unit calculates the electrical property distribution, which is the biological information, from the Jacobian matrix of the subject calculated by the Jacobian matrix calculation unit and the potential difference and phase or the current and phase measured by the in-vivo measurement unit. The pressing control unit controls the pressure of each of the pressing units based on the electrical property distribution so that interstitial fluid, lymphatic fluid, and venous blood can circulate. and so on. <2> In the massage device described in <1> above, the pressing part may be composed of one airbag. <3> In the massage device described in <1> or <2> above, the pressing part may be composed of two or more airbags, and each airbag may be able to apply a different pressure. <4> In the massage device described in <1> or <2> above, the electrodes may be arranged at equal intervals. < 5 > In the massage device described in < 1 > above, in the Jacobian matrix calculation unit, the Jacobian matrix may be calculated using machine learning. < 6 > In the massage device described in < 1 > above, the plurality of pressing parts The are arranged between the electrical impedance tomography sensors at intervals in the longitudinal direction of the affected part of the subject. When the temporal change in the electrical property distribution is smaller than a predetermined value, the pressing control unit may control the pressure of the pressing part adjacent to the electrical impedance tomography sensor that has obtained the electrical property distribution with a small temporal change so that interstitial fluid, lymphatic fluid, and venous blood can circulate. < 7 >The massage device described in the above < 1 > is The pressing part The consists of two or more airbags arranged in the circumferential direction of the affected part of the subject, and different pressures can be applied to each airbag. When the temporal change in the electrical property distribution is smaller than a predetermined value, the pressing control unit may control the pressure of each airbag in the pressing part adjacent to the electrical impedance tomography sensor that has obtained the electrical property distribution with a small temporal change so that interstitial fluid, lymphatic fluid, and venous blood can circulate.

Advantages of the Invention

[0010] According to the above aspect of the present invention, it is possible to provide a massage device capable of measuring changes in the distribution of interstitial fluid, lymphatic fluid, and venous blood in the living body due to massage.

Brief Description of the Drawings

[0011]

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Mode for Carrying Out the Invention

[0012] <First Embodiment> Hereinafter, with reference to the drawings, a massage device according to an embodiment of the present invention will be described. As shown in FIG. 1, the massage device 100 includes a pressing measurement unit 30 and a measurement calculation unit 50. The measurement calculation unit 50 includes a Jacobian matrix calculation unit 3, an electrical property distribution calculation unit 4, and an output unit 5.

[0013] The measurement calculation unit 50 of the massage device 100 includes, for example, a Central Processing Unit (CPU), a Read Only Memory (ROM), a Random Access Memory (RAM), and a Hard Disk Drive (HDD) / Solid State Drive (SSD). The Jacobian matrix calculation unit 3, the electrical property distribution calculation unit 4, and the output unit 5 are realized by the CPU executing a predetermined program. The program may be acquired via a recording medium or via a network. Also, a dedicated hardware configuration for realizing the configuration of the massage device 100 may be used. Hereinafter, each part will be described.

[0014] (Pressing Measurement Unit) The pressing measurement unit 30 will be described with reference to FIG. 2. FIG. 2 shows a schematic diagram of the pressing measurement unit 30. In the drawings used in the following description, for the sake of clarity of the features, the characteristic parts may be enlarged for convenience, and the dimensional ratios of each component may be different from the actual ones. The materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited thereto, and can be appropriately modified and implemented within the scope where the effects of the present invention can be achieved. The pressing measurement unit 30 includes a living body measurement unit 1 that measures changes in the biological information of the subject due to pressing, a plurality of pressing units 20 that press the subject, and a pressing control unit 25 that controls the pressure of the pressing units 20.

[0015] First, define the directions. Here, an example will be given and explained for the case where the subject stands on the floor surface F for measurement. One direction parallel to the floor surface F is defined as the x - direction, and along the floor surface F, the direction orthogonal to the x - direction is defined as the y - direction. The z - direction is the direction perpendicular to the floor surface F. The z - direction is orthogonal to both the x - direction and the y - direction. Hereinafter, the +z direction may be expressed as "up" and the -z direction as "down". The up and down do not necessarily coincide with the direction in which gravity acts.

[0016] (Pressing part) The pressing part 20 is not particularly limited as long as it can press the subject, and known pressing means used for massage can be used. Examples of the pressing part 20 include an airbag, a rolling ball, etc. An airbag is preferable because it can apply an appropriate pressure to the subject by expanding and contracting. In this embodiment, an airbag will be taken as an example for explanation. In this embodiment, the pressing part 20 consists of one airbag 21. Each pressing part 20 is connected to the pressing control part 25 via a flow path 22.

[0017] The number of the pressing parts 20 is, for example, 2 or more, preferably 4 or more. The more the number of the pressing parts 20, the finer the pressing area can be set. Thereby, the circulation of interstitial fluid, lymphatic fluid, and venous blood can be performed more efficiently. In this embodiment, the number of the pressing parts 20 is 4. The upper limit of the number of the pressing parts 20 is not particularly limited, but for example, it is 20.

[0018] The pressing part 20 may be provided with a pressure sensor (not shown) for measuring the pressure applied to the subject. By providing the pressing part 20 with a pressure sensor, the relationship between the applied pressure and the change in biological information can be grasped in more detail.

[0019] In the massage device 100 of the first embodiment, the pressing part 20 is arranged on the leg of the subject. In this embodiment, The It is arranged so as to cover the periphery of the operator (the periphery of the leg). Since the pressing part 20 consists of one airbag 21, the periphery of the leg where the pressing part 20 is arranged is pressed with a uniform pressure.

[0020] In the massage device 100, a plurality of pressing portions 20 are arranged at intervals with respect to the longitudinal direction of the leg of the subject. Here, the leg refers to the portion below the thigh. The leg refers to the portion of the human body from the thigh to the ankle. Also, the longitudinal direction of the leg means The the direction from the thigh to the shin when the operator stands upright. By arranging the plurality of pressing portions 20 at intervals in the longitudinal direction of the leg of the subject, for example, stagnant interstitial fluid, lymphatic fluid, and venous blood can be circulated.

[0021] The pressing portion 20 is preferably arranged between the sensors 10 for electrical impedance tomography. By arranging the pressing portion 20 in this way, it is possible to grasp which side of the sensors 10 for electrical impedance tomography the interstitial fluid, lymphatic fluid, and venous blood have moved to due to the pressing.

[0022] (Pressure control unit) The pressure control unit 25 controls the pressure of each pressing portion 20 temporally and spatially so that interstitial fluid, lymphatic fluid, and venous blood can be circulated. The temporal and spatial application method of the pressure is not particularly limited as long as interstitial fluid, lymphatic fluid, and venous blood can be circulated. The pressure control unit 25 controls a pump (not shown) that sends air to the pressing portion 20 and a solenoid valve (not shown) that controls the amount of air sent into the pressing portion 20, and controls the pressure of each pressing portion 20.

[0023] (In-vivo measurement unit) The in-vivo measurement unit 1 includes one or more sensors 10 for electrical impedance tomography and an electrical control unit 40. By applying a current or a potential difference to the subject using the sensors 10 for electrical impedance tomography, the inside of the limbs of the subject can be visualized. By observing the temporal change of the visualized internal biological information (for example, the electrical property distribution such as the conductivity distribution), the change in the distribution of interstitial fluid, lymphatic fluid, and venous blood can be grasped.

[0024] It is preferable that the in-vivo measurement unit 1 includes two or more sensors 10 for electrical impedance tomography, so that the flow of interstitial fluid, lymphatic fluid, and venous blood can be grasped. The larger the number of sensors 10 for electrical impedance tomography, the more accurately the flow of interstitial fluid, lymphatic fluid, and venous blood can be grasped.

[0025] After the subject wears the sensor 10 for electrical impedance tomography, the in-vivo measurement unit 1 applies a current or a potential difference between the electrodes 15. When applying a current, it is preferable to measure the potential difference and the phase based on a current application voltage measurement pattern described later. When applying a potential difference between the electrodes 15, it is preferable to measure the current and the phase based on a voltage application current measurement pattern described later.

[0026] When applying a current, the in-vivo measurement unit 1 measures the potential difference based on a predetermined current application voltage measurement pattern (a pattern in which two electrodes are sequentially selected from a number of electrodes, a current is applied, and the potential difference is sequentially measured). At this time, it is desirable that the in-vivo measurement unit 1 also measures the phase (the temporal shift between the applied current and the measured potential difference). When applying a potential difference, the in-vivo measurement unit 1 measures the current based on a predetermined voltage application current measurement pattern (a pattern in which two electrodes are sequentially selected from a number of electrodes, a potential difference is applied, and the current is sequentially measured). At this time, it is preferable that the in-vivo measurement unit 1 also measures the phase (the temporal shift between the applied potential difference and the measured current). Hereinafter, the case of applying a current will be mainly described, and the detailed description of the case of applying a potential difference may be omitted.

[0027] (Sensor for Electrical Impedance Tomography) As shown in FIG. 3, the sensor 10 for electrical impedance tomography according to the first embodiment includes four or more electrodes 15 (number of electrodes Q) and a support 17.

[0028] The electrode 15 is electrically connected to the electrical control unit 40. The material and shape of the electrode 15 are not particularly limited as long as a current or potential difference can be applied to the subject. Examples of the electrode 15 include metals such as Au, Ag, and Cu, conductive polymers, fibers coated with a metal on the surface, and fibers coated with a conductive polymer on the surface.

[0029] The number Q of the electrodes 15 is 4 or more. By having 4 or more electrodes 15, it is possible to estimate the electrical property distribution, which is the biological information of the subject, using the calculation result of the Jacobian matrix calculation unit 3 described later. It is preferable to have a larger number of electrodes in order to improve the accuracy of the calculation.

[0030] The arrangement position of the electrodes 15 is not particularly limited. The electrodes 15 are preferably arranged at equal intervals so as to surround the periphery of the subject (here, the periphery of the leg).

[0031] The electrical connection method between the electrode 15 and the electrical control unit 40 is not particularly limited, and a known electrical connection method can be used. In the present embodiment, each electrode 15 and the electrical control unit 40 are connected by an electric wire 41. Each electrical impedance tomography sensor 10 and the electrical control unit 40 are connected by an electric wire bundle 42 in which the electric wires 41 are bundled.

[0032] The support 17 is not particularly limited as long as it can hold the electrode 15. The support 17 is preferably capable of arranging the electrode 15 in a region near the region to be pressed of the subject. Here, "capable of being arranged in a region near the region to be pressed of the subject" means that when the subject wears the electrical impedance tomography sensor 10, the electrode 15 is arranged in a region near the region to be pressed of the subject. The region near the region to be pressed is a region adjacent to the region pressed by the pressing unit 20, and is a region where the distribution of interstitial fluid, lymphatic fluid, and venous blood changes due to the pressing. The region near the region to be pressed is, for example, a region from 0 cm to 10 cm from the pressing unit 20.

[0033] The support body 17 preferably allows a predetermined pressure to be applied such that the electrode 15 can be closely attached to the subject. This improves the adhesion between the electrode 15 and the subject, enabling the current or potential difference to be applied more accurately and the potential difference or current to be measured. The material of the support body 17 is not particularly limited, and for example, insulators such as elastomers, leather, and cloth are preferred. The shape of the support body 17 is not particularly limited, and examples include boot-shaped and band-shaped.

[0034] (Electric control unit) The electric control unit 40 includes, for example, a multiplexer for switching between a current application electrode (or voltage application electrode for applying a potential difference) for applying current and a voltage measurement electrode (or current measurement electrode for measuring current) for measuring potential difference, and an impedance analyzer for performing voltage measurement (or current measurement) and phase measurement. An impedance analyzer is a component that measures the impedance, that is, the ratio of the measured potential difference (applied potential difference) to the applied current (measured current), and its phase, by changing the applied frequency and amplitude. The electric control unit 40 performs impedance measurement (measurement of the ratio of potential difference to current and its phase) by, for example, executing a predetermined program in the CPU to control the multiplexer and the impedance analyzer. The electric control unit 40 may be controlled and impedance measurement may be performed only inside the in-vivo measurement unit 1, or the electric control unit 40 may be controlled according to the program executed by the measurement calculation unit 50 to perform impedance measurement. The result of the impedance measurement is sent to the electrical property distribution calculation unit 4. The method of transmitting information to the electrical property distribution calculation unit 4 is not particularly limited. It may be sent from the electric control unit 40 to the electrical property distribution calculation unit 4 of the measurement calculation unit 50 by wire, or it may be sent to the electrical property distribution calculation unit 4 of the measurement calculation unit 50 wirelessly.

[0035] The electric control unit 40 applies a current between the electrodes 15 and measures the potential difference based on a predetermined current application voltage measurement pattern (a pattern indicating between which electrodes to apply the current and between which electrodes to measure the potential difference). Alternatively, the electric control unit 40 applies a potential difference between the electrodes 15 and measures the current based on a predetermined voltage application current measurement pattern. When applying the current, and similarly when applying the potential difference, there are no particular limitations on between which electrodes 15 to apply the current (potential difference) and between which electrodes to measure the potential difference (current), but it is preferable to apply the current (potential difference) "uniformly" to the arranged electrodes 15 and measure the potential difference (current). "Applying the current (potential difference) uniformly and measuring the potential difference (current)" means applying and measuring the current and potential difference so that all the electrodes 15 are used for applying or measuring the current and potential difference at least once. Note that the current application voltage measurement pattern described below can also be applied to the voltage application current measurement pattern. The value of the applied current and its application frequency are preferably alternating currents in the range from about Hz band to MHz band of 1.0 mA or less in view of the influence on the living body and the simplicity of the device.

[0036] Taking the electrode arrangement in FIG. 4 as an example, the current application voltage measurement pattern for the electrodes 15 will be described. The numbers representing the positions of the electrodes 15 are, for example, numbered counterclockwise from the reference first electrode. The number M of the current application voltage measurement patterns is different for each current application voltage measurement pattern. Hereinafter, each current application voltage measurement pattern will be described. Hereinafter, examples of the current application voltage measurement pattern will be described, but the present invention is not limited to the following current application voltage measurement patterns.

[0037] First, the current application voltage measurement pattern by the counter electrode method will be described. In this case, a current is applied between a pair of opposing electrodes. For example, referring to Fig. 4(a), a current is applied to the opposing electrodes such as between electrode 1 and electrode 9, and between electrode 2 and electrode 10. In the case of Fig. 4(a), since the number of electrodes Q is 16, there are a total of 8 ways. The potential difference is measured in electrode pairs such as between the second electrode and the third electrode excluding the electrodes to which the current is applied, and between the third electrode and the fourth electrode, and is measured from the electrode pair of the second electrode and the third electrode to the electrode pair of the 15th electrode and the 16th electrode. Therefore, in one current application pattern, there are 13 voltage measurement patterns. Thus, in the case of the counter electrode method, the number of measurements (measurement patterns) M is 104 in total. Here, when a current is applied to measure the potential difference, the measurement pattern becomes a voltage measurement pattern. When a potential difference is applied to measure the current, the measurement pattern becomes a current measurement pattern.

[0038] Next, the current application voltage measurement pattern by the adjacent electrode method will be described. In this case, a current is applied between adjacent electrodes. For example, referring to Fig. 4(b), a current is applied to adjacent electrodes such as between electrode 1 and electrode 2, and between electrode 2 and electrode 3. In the case of Fig. 4(b), since the number of electrodes Q is 16, there are 16 ways in total. The potential difference is measured in electrode pairs such as between the third electrode and the fourth electrode excluding the electrodes to which the current is applied, and is measured from the third electrode and the fourth electrode to the 15th electrode and the 16th electrode. Therefore, in one current application pattern, there are 13 voltage measurement patterns. Thus, in the case of the adjacent electrode method, the number of measurements (measurement patterns) M is 208 in total.

[0039] The current application voltage measurement pattern by the reference method will be described. In this case, the potential difference is measured for all combinations between the reference electrode and the electrodes other than the reference electrode. For example, referring to FIG. 4(c), a current is applied between the reference electrode and the electrodes other than the reference electrode, such as between the first electrode and the second electrode, and between the first electrode and the third electrode. In the case of FIG. 4(c), since the number of electrodes Q is 16, there are a total of 16 combinations. The potential difference is measured in electrode pairs such as the third electrode and the fourth electrode excluding the electrodes to which the current is applied, and is measured from the electrode pair of the third electrode and the fourth electrode to the electrode pair of the 15th electrode and the 16th electrode. Therefore, in one current application pattern, there are 13 voltage measurement patterns. Thus, in the reference method, the total number of measurements (measurement patterns) M is 208.

[0040] Hereinafter, in the massage device 100 of the present embodiment, an example of measuring the potential difference using the adjacent method will be described. In the following, a calculation example for one electrical impedance tomography sensor 10 will be described, but the same calculation can be performed when there are two or more electrical impedance tomography sensors 10.

[0041] (Jacobian matrix calculation unit 3) The Jacobian matrix is a sensitivity matrix that indicates how much the measured potential difference when a current is applied (or the measured current when a voltage is applied) changes with respect to changes in the reference of the electrical properties (conductivity, permittivity) distributed in space. The Jacobian matrix (sensitivity matrix) of the subject varies depending on the spatial distribution of the electrical properties of the subject, the body shape, etc. If the Jacobian matrix of the subject is known, the electrical property distribution can be calculated. The Jacobian matrix calculation unit 3 uses a predetermined current application voltage measurement pattern (or voltage application current measurement pattern), and the mesh coordinates obtained by dividing the contour of the subject measured in advance and the coordinates of the electrodes 15 to calculate the Jacobian matrix J* of the interior Ω of the subject (* is a symbol meaning estimated for the subject). In the present embodiment, the mesh coordinates obtained by dividing the contour of the subject are the leg contour ∂Ω of the subject (mesh coordinates obtained by dividing the leg contour ∂Ω). The Jacobian matrix calculation unit 3 may calculate the Jacobian matrix J* using the following formula (9) based on, for example, an X-ray image or an MRI image of the inside of the subject's own leg taken in advance, and create the Jacobian matrix J* made to order (made to order of the Jacobian matrix J*), or (2) based on general information such as age, gender, nationality, height, weight, etc., the three-dimensional position information of fat, muscle, and bone inside the leg and all forms G leg contours ∂Ω are used as the first database, and from the first database, a second database (a dataset I of known leg contours ∂Ω and a dataset J of known Jacobian matrices of the inside of the leg Ω) is created, and from the second database, for the leg contour ∂Ω of the subject, the optimal Jacobian matrix J* of the subject may be selected using machine learning or the like. Here, the leg contour ∂Ω of the subject refers to the leg contour of the subject in the region where the electrodes 15 are arranged. In the present embodiment, the case of the leg is described as an example, but the present invention can also be applied to the arm, abdomen, etc. When applying to the arm, the contour of the arm is used, and when applying to the abdomen, the contour of the abdomen is used.

[0042] The first and second databases (2) will be described below with reference to Fig. 5. Here, the legs of a patient will be taken as an example for description, but the present invention can be applied not only to legs, but also to arms, abdomen, etc. First, in the first database, for example, information on G leg contours ∂Ω of various shapes (geometry) assuming fat and thin people is prepared for generally available leg contour information of healthy people of a certain age, nationality, and sex (for example, a generally available 3D image of the legs) (for example, an image obtained by processing a generally available 3D image assuming fat and thin people).

[0043] In the first database, the leg contour ∂Ω of the gth geometry g For Q electrodes 15, depending on their internal Ω, a suitable resolution is obtained. g For example, if there are Q=16 electrodes 15, the known leg contour ∂Ω is divided into two-dimensional meshes. g The region including the above may be divided into 64 in the x direction and 64 in the y direction, resulting in a total of 4096 points, to create mesh n (1≦n≦N). In this case, N is 4096. The number of meshes and their shape can be set appropriately according to the number of electrodes 15 and the required resolution. This operation may be performed in the first database, or in the next second database.

[0044] Next, we will explain the data set I of the known leg contour ∂Ω for the information of the leg contour ∂Ω of G geometries in the second database. The data set I of the known leg contour ∂Ω is a matrix consisting of data of the known leg contour ∂Ω with elements of (Q+2)×N (number of spatial meshes)×G (number of geometries in the first database). Here, Q is strictly the number of contour measurement points and may take a value different from the number of electrodes, but for convenience here, the number of contour measurement points Q and the number of electrodes Q are set to the same value. The data set I of the leg contour ∂Ω is composed of the measured contour ∂Ω of the subject, N mesh coordinates (x n ,y n), and is composed of the distance r from the origin O to each electrode 15. The meaning of 2 in Q+2 is the coordinate position (x n , y n ) in the g-th geometry and the n-th mesh, and the meaning of Q is the radius r of the contour measurement point Q in the g-th geometry.

[0045] The dataset I is represented by the following formula (1). I g is an input variable in the known leg contour ∂Ω g and is represented by the following formula (2). I in formula (2) g n is an input variable of mesh n in the known leg contour ∂Ω g and is represented by the following formula (3). X in formula (3) g n is the Cartesian coordinate (x g of mesh n in the known leg contour ∂Ω n , y n ) and is represented by the following formula (4). r in formula (3) g is the distance from the origin of the electrode 15 arranged in the known leg contour ∂Ω g and is represented by the following formula (5). Q in formula (5) indicates the number of contour measurement points (which may be the same as the number of electrodes). Note that T in the formula indicates the transpose of the matrix element, the right side R indicates the set of real numbers, the superscript indicates the element of the matrix or the element of the column vector, and the subscript indicates the element of the row vector.

[0046]

Equation

[0047] The dataset J of the Jacobian matrix of the known leg interior Ω can be created, for example, by using the finite element method from the aforementioned first database and any form of leg contour ∂Ω to calculate the Jacobian matrix J. Since the Jacobian matrix J changes depending on the leg contour ∂Ω of the subject, it is preferable to prepare a number of known leg contours ∂Ω and Jacobian matrices J. Here, the known leg contour ∂Ω is denoted as ∂Ω gLet (1 ≦ g ≦ G). G is the number of known leg contours ∂Ω in the dataset, for example, from 100 to 10,000. ∂Ω g The type of ∂Ω and the number of G can be modified as appropriate. The dataset J of the Jacobian matrix of the known leg interior Ω is a known sensitivity matrix with elements of M (the number of current application voltage measurement patterns) × N (the number of spatial meshes) × G (the number of the first database). G two-dimensional shapes are referred to as the X vector, and the data of a plurality of Jacobian matrices J obtained from a plurality of known sample leg contours ∂Ω by the finite element method or the like. The dataset J of the Jacobian matrix is a sensitivity matrix of a predetermined current application voltage measurement pattern (or voltage application current measurement pattern).

[0048] The Jacobian matrix J of the leg contour ∂Ω is represented by the following formula (6). M in formula (6) indicates the number of current application voltage measurement patterns, N indicates the number of meshes, and G indicates the number of geometries. The Jacobian matrix J of geometry g (1 ≦ g ≦ G) g is shown by formula (7), and the Jacobian matrix J at mesh n (1 ≦ n ≦ N) of geometry g (1 ≦ g ≦ G) g n is shown by formula (8). The Jacobian matrix element J at current application voltage measurement pattern m (1 ≦ m ≦ M) and at mesh n (1 ≦ n < N) of geometry g (1 ≦ g ≦ G) g nm is calculated using the following formula (9). Here, σ n indicates the conductivity at mesh n as an example of the electrical property distribution, but other electrical property distributions (conductivity difference distribution Δσ, permittivity distribution, permittivity difference distribution, phase distribution, phase difference distribution) may also be used. A n indicates the area of the nth mesh, but when it is desired to calculate simply due to computational cost or the like, the mesh area in the x - y direction may be used and approximated in the z direction. Vm(e, d) indicates the measured potential difference V at current application voltage measurement pattern m. e indicates the current application electrode pair at current application voltage measurement pattern m, and d means the voltage measurement electrode pair at current application voltage measurement pattern m. V(i e ) indicates the potential difference between voltage measurement electrode pair d induced by applying current to current application electrode pair e. V(i d) is the potential difference between the current application electrode pair e induced by applying current to the voltage measurement electrode pair d. ∇ is the nabla symbol and is a differential operator.

[0049]

Number

[0050] Hereinafter, a method for calculating the Jacobian matrix J* (the * is a symbol meaning estimated for the subject) of the subject's leg contour ∂Ω will be described based on a predetermined current application voltage measurement pattern m (1 ≤ m ≤ M) using the data set J of the Jacobian matrix of the known leg interior Ω and the data set of the known leg contour ∂Ω output from the second database of FIG. 5. When calculating the Jacobian matrix J*, the data set I of the leg contour ∂Ω and the data set J of the Jacobian matrix of the leg interior Ω are used as input variables, and the Jacobian matrix J* of the subject is calculated using machine learning such as the nearest neighbor search method or a neural network. The nearest neighbor search method is not particularly limited, and examples include the k-nearest neighbor method, approximate nearest neighbor search, locality-sensitive hashing, and kd-tree. When using a neural network, for example, it corresponds to the above-mentioned "custom-made Jacobian matrix J*". That is, from the X-ray image or MRI image of the interior of the subject's own leg taken in advance, the spatial position information of tissues such as fat, muscle, and bone is known, and the spatial position information of conductivity and permittivity is also known. And in this known object, the voltage value when current is applied between each electrode is known by actually measuring the subject himself / herself, or is known by using electromagnetic calculation or the like without actually measuring the voltage value. That is, since the Jacobian matrix J* is a physical quantity that connects the spatial position information of conductivity and permittivity, which are input values, and the spatial position information of tissues, which are output values, even if the relationship between the two is not strongly formulated as non-linear, J* can be obtained by using a neural network. Hereinafter, the k-nearest neighbor method will be described as an example.

[0051] Next, a method for calculating the Jacobian matrix J* of the subject by the K-nearest neighbor method will be described with reference to FIG. 6. The Jacobian matrix calculation unit 3 divides the leg contour ∂Ω* of the subject into the same number of meshes N as the dataset of the known leg contour ∂Ω g . Then, from the previously determined current application voltage measurement pattern m and the coordinates of the electrodes 15, the input variable I * is created for the mesh n (S12). The input variable I * is the input variable at the leg contour ∂Ω* of the subject and is represented by the following formula (10). I in formula (10) * n is the input variable of the mesh n at the leg contour ∂Ω of the subject and is represented by the following formula (11). X* in formula (11) n is the Cartesian coordinates (x* n , y* n ) of the mesh n at the leg contour ∂Ω of the subject and is represented by the following formula (12). T indicates the transpose of the matrix element. r in formula (11) * is the distance from the origin O of the electrode 15 (precisely, the contour measurement point) arranged at the leg contour ∂Ω of the subject and is represented by the following formula (13). Q in formula (13) indicates the number of electrodes 15 (precisely, the contour measurement points).

[0052]

Equation

[0053] Next, the calculation process of the Jacobian matrix J * of the subject by the K-nearest neighbor algorithm (K-NN) will be described. The Jacobian matrix calculation unit 3 inputs an initial value (for example, n = 1, m = 1) (S13). Next, the Jacobian matrix calculation unit 3 first calculates the Euclidean distance matrix C between the measured I * of the subject and the dataset I of the known leg contour ∂Ω which is the output from the second database. The Euclidean distance matrix C is represented by the following formula (14), and the number K of clusters with a small Euclidean distance from I * nm and the input variable I gnm is shown. The number of clusters K is not particularly limited and is, for example, 5. The Euclidean distance matrix C consists of elements K×N of the number of clusters K and the number of meshes N determined independently. The Euclidean distance matrix Cn in mesh n (1 ≦ n ≦ N) is shown by the following formula (15), and I g n and I * n show the Euclidean distance between, and the measured I of the subject * and the known leg contour ∂Ω of the geometry g (1 ≦ g ≦ G) of the dataset I g is determined to be minimized. Next, using the Euclidean distance matrix C and the dataset J of the Jacobian matrix of the known leg interior Ω, the Jacobian matrix J * n (the number of elements is M) of the subject when n is fixed is calculated (S15). It is calculated by the following formula (16), and J g n represents the Jacobian matrix of the current application voltage measurement pattern m at mesh n in the known leg contour ∂Ω g . In FIG. 6, for example, taking the position of mesh n = 5 as an example, an example of I5 * is described.

[0054] J nm * After the calculation of is completed, the Jacobian matrix calculation unit 3 determines whether the number of n is equal to the number of meshes N (S16). If n and N are not equal, the number of n is incremented by 1 and the process returns to S15 again (S16). If n and N are equal, then it is determined whether m is equal to the number of current application voltage measurement patterns M (S17). If m and M are not equal, the number of m is incremented by 1 and the process returns to S14 again (S17). If n and m are equal to N and M respectively, the Jacobian matrix calculation unit 3 finishes the calculation of the Jacobian matrix J * of the subject (S18) and sends the Jacobian matrix J * of the subject to the electrical property distribution calculation unit 4. When calculating the Jacobian matrix J using a normal personal computer without using machine learning using the above formula (9), it takes more than 5 minutes for the calculation. The known dataset I and the leg contour ∂Ω gPrepare a dataset J of the Jacobian matrix, and based on the leg contour ∂Ω of the subject and the current application voltage measurement pattern, by using machine learning such as the K-nearest neighbor method, the Jacobian matrix J of the subject * can be calculated with high accuracy in a short time.

[0055]

Number

[0056] (Electrical property distribution calculation unit) The electrical property distribution calculation unit 4 calculates the electrical property distribution of the subject from the Jacobian matrix J of the subject sent from the Jacobian matrix calculation unit 3 * and the potential difference and phase (or current and phase) measured by the in-vivo measurement unit 1. Here, the electrical property distribution is, for example, the conductivity distribution σ, the conductivity difference distribution Δσ, the permittivity distribution, the permittivity difference distribution, the phase distribution, and the phase difference distribution, etc. Hereinafter, when distinguishing between the conductivity and the conductivity difference (conductivity at time t with respect to the reference at time t0), the symbol Δ is used as the symbol representing the difference.

[0057] The following describes the conductivity difference distribution Δσ with focus. The known Jacobian matrix J of the subject * and the measured known potential difference ΔV (potential difference at time t with respect to the reference at time t0), the problem of obtaining the conductivity difference distribution Δσ is called an ill-posed inverse problem and can be obtained, for example, by using iterative calculation. The number of iterations is represented by the rightmost digit. The initial conductivity difference distribution Δσ at the 0th iteration 0 is (the upper right digit is the number of iterations), the Jacobian matrix J of the subject *It is calculated from the following formula (17). T represents a transposed matrix. ΔV in formula (17) is a column vector having M elements of a predetermined current application voltage measurement pattern (or voltage application current measurement pattern) as shown in the following formula (18). There are two ways to process ΔVm in formula (18), namely, a method using a measurement time difference with a constant applied current frequency and a method using several applied current frequency differences with a constant measurement time. Here, when describing the method using a measurement time difference, the measured potential ΔV m (t0) is used as a reference, and the measured potential difference ΔV from the measured potential ΔV m (t) at time t is used and represented by the following formula (19). Also, this formula may be divided by V m (t0). m in formula (19) is a current application voltage measurement pattern. The conductivity difference distribution Δσ of the subject is calculated using the following formula (20) starting from the initial conductivity difference distribution Δσ 0 . i in formula (20) represents the number of iterative calculations. R in formula (20) is a regularization matrix, λ represents an arbitrary parameter for converging the calculation, for example, 0.01. R is represented by, for example, the following formula (21) and is a function of the Jacobian matrix J * of a known subject. The calculated electrical property distribution (here, the conductivity difference distribution Δσ) of the subject is sent to the output unit 5.

[0058] [Number]

[0059] (Output unit) The output unit 5 outputs electrical property distributions such as the conductivity distribution σ, conductivity difference distribution Δσ, permittivity distribution, permittivity difference distribution, phase distribution, and phase difference distribution calculated by the electrical property distribution calculation unit 4. These electrical property distributions may be converted into 3D (three-dimensional) images of a two-dimensional space and time, 3D images with time fixed, 1D (one-dimensional) values obtained by spatially averaging the images of the two-dimensional space, and time-averaged values obtained by temporally averaging, and their outputs may be displayed. Also, two-dimensional images or the like may be displayed for each electrical impedance tomography sensor 10. The output destination of the output unit 5 is not particularly limited. The output destination may be a display unit such as a liquid crystal display or a storage device such as an HDD. Hereinafter, < > may be used as the symbol for spatial averaging.

[0060] As described above, the massage device 100 according to this embodiment has been described in detail. The massage device 100 The Since it can grasp the changes in the biological information inside the operator (changes in the electrical property distribution), the subject can grasp whether the interstitial fluid, lymphatic fluid, and venous blood are sufficiently circulating. Also, since the massage device 100 includes two or more electrical impedance tomography sensors 10, it is possible to grasp in which direction the interstitial fluid, lymphatic fluid, and venous blood have flowed due to the pressing.

[0061] In the first embodiment, an airbag is used for the pressing unit 20, but the pressing unit 20 may be a rolling ball. Also, in the first embodiment, since an airbag was used, the flow path 22 was used, but when the pressing unit 20 can be driven electrically, an electric wire may be used instead of the flow path 22. And, in the first embodiment, there were three electrical impedance tomography sensors 10, but even one may be used. Even if there is one electrical impedance tomography sensor 10, it is possible to measure the temporal change in biological information due to pressing. The massage device 100 according to this embodiment is worn on the leg, but it may be worn on the arm, abdomen, or the like. In that case, the contour used for the calculation of the Jacobian matrix will be the contour of the arm, the contour of the abdomen, or the like.

[0062] <Second Embodiment> Next, the second embodiment will be described. As shown in FIG. 7, the massage device 100A according to the second embodiment includes a pressing measurement unit 30A and a measurement calculation unit 50A. The measurement calculation unit 50A includes a Jacobian matrix calculation unit 3, an electrical property distribution calculation unit 4A, and an output unit 5. In this second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted, and only the differences will be described.

[0063] (Pressing measurement unit) The pressing measurement unit 30A includes a living body measurement unit 1, a plurality of pressing units 20, and a pressing control unit 25A.

[0064] (Pressing control unit) The pressing control unit 25A controls the pressure of each pressing unit 20 temporally and spatially so that interstitial fluid, lymphatic fluid, and venous blood can circulate. The pressing control unit 25A controls the pressure of the pressing unit 20 based on the electrical property distribution of the subject sent from the electrical property distribution calculation unit 4A of the measurement calculation unit 50A. For example, when the temporal change in the electrical property distribution obtained by the electrical impedance tomography sensor 10 is small (when the circulation of interstitial fluid, lymphatic fluid, and venous blood is not sufficient), the pressure of the pressing unit 20 adjacent to the electrical impedance tomography sensor 10 that has obtained the electrical property distribution with a small temporal change is controlled to press so that interstitial fluid, lymphatic fluid, and venous blood can circulate. In this way, by controlling the pressing unit 20 based on the electrical property distribution, interstitial fluid, lymphatic fluid, and venous blood can be circulated in a shorter time. The pressing control unit 25A controls a pump (not shown) that sends air to the pressing unit 20 and a solenoid valve (not shown) that controls the amount of air sent into the pressing unit 20 to control the pressure of each pressing unit 20.

[0065] (Electrical property distribution calculation unit) The electrical property distribution calculation unit 4A receives the Jacobian matrix J of the subject sent from the Jacobian matrix calculation unit 3 *And, the electrical property distribution of the subject is calculated from the potential difference and phase (or current and phase) measured by the in-vivo measurement unit 1. The electrical property distribution calculation unit 4A calculates the electrical property distribution of the subject in the same manner as the electrical property distribution calculation unit 4. The obtained electrical property distribution of the subject is sent to the output unit 5 and the pressing control unit 25A.

[0066] As described above, the second embodiment has been explained. In the massage device 100A of the second embodiment, since the pressing control unit 25A adjusts the pressure of the pressing unit 20 according to the electrical property distribution of the subject obtained by the electrical property distribution calculation unit 4A, the massage can be completed in a shorter time than usual.

[0067] <Third Embodiment> Next, the third embodiment will be described. As shown in FIG. 8, the massage device 100B according to the third embodiment includes a pressing measurement unit 30B and a measurement calculation unit 50A. The measurement calculation unit 50A includes a Jacobian matrix calculation unit 3, an electrical property distribution calculation unit 4A, and an output unit 5. In this third embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof is omitted, and only the differences will be described.

[0068] (Pressing Measurement Unit) The pressing measurement unit 30B includes an in-vivo measurement unit 1, a plurality of pressing units 20B, and a pressing control unit 25B.

[0069] (Pressing Unit) The pressing part 20B is not particularly limited as long as it can press the subject, and known pressing means used for massage can be used. Examples of the pressing part 20B include an airbag and a knobby ball. An airbag is preferable because it can apply an appropriate pressure to the subject by expanding and contracting. In the third embodiment, the airbag will be described as an example. As shown in FIG. 9, in the present embodiment, the pressing part 20B is composed of two or more airbags 21. The number of airbags 21 is preferably three or more, and more preferably four or more. Each airbag 21 can apply a different pressure. It is preferable that the number of airbags 21 constituting the pressing part increases because the pressing area can be controlled more finely. The airbag 21 is arranged in the circumferential direction of the subject (for example, the circumferential direction of the leg). Each airbag 21 of the pressing part 20B is connected to the pressing control part 25B via the flow path 22.

[0070] The number of the pressing parts 20B is, for example, two or more, and preferably four or more. The larger the number of the pressing parts 20B, the finer the pressing area can be set. As a result, the circulation of interstitial fluid, lymphatic fluid, and venous blood can be performed more efficiently. In the present embodiment, the number of the pressing parts 20B is four. The upper limit of the number of the pressing parts 20B is not particularly limited, but is, for example, 20.

[0071] The pressing part 20B may be provided with a pressure sensor (not shown) for measuring the pressure applied to the subject. In the present embodiment, by providing a pressure sensor for each airbag 21 included in the pressing part 20B, the relationship between the applied pressure and the change in biological information can be grasped in more detail.

[0072] In the massage device 100B of the third embodiment, the pressing part 20B is arranged so as to cover the periphery of the leg of the subject. That is, a plurality of airbags 21 are arranged in the circumferential direction of the leg. Since the plurality of airbags 21 are arranged in the circumferential direction of the leg, the pressure of the airbag 21 can be changed in the circumferential direction to press the subject. As a result, the stagnant interstitial fluid, lymphatic fluid, and venous blood can be circulated more efficiently.

[0073] In the massage device 100B, a plurality of pressing parts 20B are arranged at intervals with respect to the longitudinal direction of the leg of the subject. By arranging the plurality of pressing parts 20B at intervals in the longitudinal direction of the leg of the subject, for example, interstitial fluid, lymph fluid, and venous blood staying in a standing posture can be circulated.

[0074] The pressing part 20B is preferably arranged between the sensors 10 for electrical impedance tomography. By arranging the pressing part 20 in this way, it is possible to grasp which side of the sensors 10 for electrical impedance tomography the interstitial fluid, lymph fluid, and venous blood have moved to due to the pressing.

[0075] (Pressing control unit) The pressing control unit 25B controls the pressure of each pressing part 20B temporally and spatially so that interstitial fluid, lymph fluid, and venous blood can be circulated. The pressing control unit 25B controls the pressure of the pressing part 20B based on the electrical property distribution of the subject sent from the electrical property distribution calculation unit 4A of the measurement calculation unit 50A. When the change in the electrical property distribution of each sensor 10 for electrical impedance tomography is small and the circulation of interstitial fluid, lymph fluid, and venous blood is not sufficient, the pressure of each airbag 21 in the pressing part 20B adjacent to the sensor 10 for electrical impedance tomography where the small change in the electrical property distribution is obtained is controlled, and pressing is performed so that interstitial fluid, lymph fluid, and venous blood can be circulated. In this way, by controlling each airbag 21 in the pressing part 20B based on the electrical property distribution, interstitial fluid, lymph fluid, and venous blood can be circulated in a shorter time than in the case of the second embodiment. The pressing control unit 25B controls a pump (not shown) that sends air to the pressing part 20 and a solenoid valve (not shown) that controls the amount of air sent into the pressing part 20, and controls the pressure of each airbag 21 in each pressing part 20B.

[0076] The above described the third embodiment. The massage device 100B of the third embodiment can complete the massage more effectively in a shorter time because the pressing control unit 25B adjusts the pressure of each airbag 21 of the pressing unit 20B according to the electrical property distribution of the subject obtained by the electrical property distribution calculation unit 4A.

[0077] <Fourth Embodiment> Next, the fourth embodiment will be described. As shown in FIG. 10, the massage device 100C according to the fourth embodiment includes a pressing measurement unit 30C and a measurement calculation unit 50C. The measurement calculation unit 50C includes a contour estimation unit 2, a Jacobian matrix calculation unit 3C, an electrical property distribution calculation unit 4C, and an output unit 5. In this fourth embodiment, the same components as those in the first, second, and third embodiments are denoted by the same reference numerals, and the description thereof is omitted, and only the differences will be described.

[0078] (Pressing Measurement Unit) The pressing measurement unit 30C includes a living body measurement unit 1C, a plurality of pressing units 20, and a pressing control unit 25.

[0079] (Living Body Measurement Unit) As shown in FIG. 11, the living body measurement unit 1C includes an electrical impedance tomography sensor 10C and an electrical control unit 40. By applying a current or a potential difference to the subject using the electrical impedance tomography sensor 10C, the inside of the subject can be visualized. Also, by observing the time change of the visualized internal biological information (for example, conductivity distribution), the changes in the distribution of interstitial fluid, lymphatic fluid, and venous blood can be grasped.

[0080] It is preferable that the in-vivo measurement unit 1C includes two or more sensors 10C for electrical impedance tomography. By including two or more sensors 10C for electrical impedance tomography in the in-vivo measurement unit 1C, the flow of interstitial fluid, lymphatic fluid, and venous blood can be grasped. The more sensors 10C for electrical impedance tomography there are, the more accurately the flow of interstitial fluid, lymphatic fluid, and venous blood can be grasped. Therefore, the upper limit of the number of sensors 10C for electrical impedance tomography is not particularly limited.

[0081] After the subject wears the sensor 10C for electrical impedance tomography, the in-vivo measurement unit 1C applies a predetermined current or potential difference between the electrodes 15 and measures the potential difference or current. When applying a current, the potential difference is measured based on a predetermined current application voltage measurement pattern (a pattern in which two electrodes are sequentially selected from a number of electrodes, a current is applied, and the potential difference is sequentially measured). At this time, it is desirable to also measure the phase (the temporal deviation between the applied current and the measured potential difference). When applying a potential difference, the current is measured based on a predetermined voltage application current measurement pattern (a pattern in which two electrodes are sequentially selected from a number of electrodes, a potential difference is applied, and the current is sequentially measured). At this time, it is preferable to also measure the phase (the temporal deviation between the applied potential difference and the measured current).

[0082] The in-vivo measurement unit 1C measures the coordinates of the contour measurement points 26 shown in FIG. 12 using the sensor 10C for electrical impedance tomography. Information such as the obtained coordinates of the contour measurement points 26 is sent to the contour estimation unit 2 of the measurement calculation unit 50C.

[0083] (Sensor for Electrical Impedance Tomography) As shown in FIG. 12, the sensor 10C for electrical impedance tomography includes four or more electrodes 15 (electrode number Q), a stretch sensor 18 that measures displacement in the stretching direction, a bend sensor 19 that measures displacement in the bending direction, and a support 17 that holds the electrodes 15, the stretch sensor 18, and the bend sensor 19. As shown in FIG. 12, for example, the stretch sensor 18 and the bend sensor (angle detection sensor) 19 are arranged at four or more contour measurement points 26 on the support 17. By providing the sensor 10 for electrical impedance tomography with coordinate measurement means capable of measuring the coordinate positions of the electrodes 15 such as the stretch sensor 18 and the bend sensor 19, the Jacobian matrix can be calculated in the Jacobian matrix calculation unit 3 without previously measuring the positions of the respective electrodes 15.

[0084] The stretch sensor 18 is a stretchable strain sensor. The stretch sensor 18 measures the displacement in the stretching direction near the contour measurement point 26 when the subject wears the sensor 10C for electrical impedance tomography on the support 17. In the fourth embodiment, the contour measurement point 26 is the arrangement position of the electrode 15.

[0085] The bend sensor 19 is a sensor capable of measuring angular displacement. The bend sensor 19 measures the displacement in the bending direction near the contour measurement point 26 when the subject wears the sensor 10C for electrical impedance tomography.

[0086] (Contour estimation unit) The contour estimation unit 2 determines, before the subject wears the electrical impedance tomography sensor 10C, a reference point for the coordinates (x, y) of the contour measurement points 26, and estimates the leg contour ∂Ω of the subject from the changes in the coordinates (x, y) of the contour measurement points 26 after the subject wears the electrical impedance tomography sensor 10C. The stretch sensor 18 and the bend sensor 19 are preferably located at the same positions as those of the respective electrodes 15, but for the x-position and the y-position, they may be provided at independent positions or arranged in the vicinity of the coordinates (x, y) of the electrodes 15. Using the data from the stretch sensor 18 and the bend sensor 19, the contour estimation unit 2 estimates the two-dimensional leg contour ∂Ω of the subject for each electrical impedance tomography sensor 10C from the x-coordinate and the y-coordinate of each contour measurement point 26 within the electrical impedance tomography sensor 10C. To obtain the leg contour ∂Ω of the subject from the coordinate data of the contour measurement points 26, the contour estimation unit 2 interpolates between the contour measurement points 26 (between each coordinate point). The contour estimation unit 2 estimates the contour ∂Ω of the subject with higher accuracy using the position coordinates of the contour measurement points 26 and an interpolation curve such as a B-spline curve. As the interpolation curve, in addition to the B-spline curve, a Bezier curve, a Lame curve, etc. may be used. The position of the q-th electrode 15 is represented by the length r q from the electrode position to the center (origin) O of the electrical impedance tomography sensor 10C, and the angle θ formed between the line connecting the position of the electrode 15 and the origin O and the x-axis. The information on the obtained leg contour ∂Ω of the subject is sent to the Jacobian matrix calculation unit 3C.

[0087] (Jacobian matrix calculation unit) The Jacobian matrix calculation unit 3C uses a previously determined current application voltage measurement pattern (or voltage application current measurement pattern) of the electrode 15, and the leg contour ∂Ω of the subject (mesh coordinates obtained by dividing the leg contour ∂Ω) estimated by the contour estimation unit 2 and the coordinates of the electrode 15 to calculate the Jacobian matrix J* (* is a symbol meaning estimated for the subject) of the internal Ω of the subject. The Jacobian matrix calculation unit 3C sends the Jacobian matrix J * of the subject to the electrical property distribution calculation unit 4. The Jacobian matrix can be calculated by the same method as that of the Jacobian matrix calculation unit 3.

[0088] The above has described the fourth embodiment. In the fourth embodiment, the sensor 10C for electrical impedance tomography measures the coordinates of the electrodes 15, and the contour estimation unit 2 can estimate the contour of the subject. Therefore, it is not necessary to measure the contour of the subject, and it is also possible to cope with the daily fluctuations in the contour of the subject.

[0089] In the fourth embodiment, the contour ∂Ω of the subject is estimated by using the stretch sensor 18 and the bend sensor 19, but only one of the stretch sensor 18 and the bend sensor 19 may be used. Also, for example, by using a support 17 of a standard size such as S, M, L, etc., the leg contour ∂Ω of the subject may be simply estimated.

[0090] <Fifth Embodiment> Next, the massage device 100D according to the fifth embodiment will be described. As shown in FIG. 13, the massage device 100D is a chair-type massage device.

[0091] The massage device 100D includes a base 61 installed on the floor surface to support the entire chair, a seat 62 that supports the buttocks of the subject above the base 61, a backrest portion 63 disposed on the rear side of the seat 62 to support the back of the subject, an elbow rest portion 64 that supports the elbows of the subject on both sides of the seat 62, and a leg support portion 65 disposed on the front side of the seat 62 to support the legs of the subject. The electrical control unit 40, the pressing control unit 25, the measurement calculation unit 50, etc. of the in-vivo measurement unit 1 are disposed inside the massage device 100D (for example, below the seat 62).

[0092] The massage device 100D includes an electrical impedance tomography sensor 10D connected via an electrical control unit 40 and an electric wire bundle 42 inside the massage device 100D. As shown in FIG. 14, the support 17D of the electrical impedance tomography sensor 10D may be band-shaped, or if it is difficult to cover the entire circumference of the leg, it may not be band-shaped but only a part in the circumferential direction. Further, the support 17D of the electrical impedance tomography sensor 10D is provided with a detachable part 45 to facilitate attachment and detachment. The detachable part 45 is, for example, a hook-and-loop fastener. Since the detachable part 45 is provided, the subject can easily attach the electrical impedance tomography sensor 10 to the part where they want to see the effect of the massage.

[0093] The massage device 100D includes a pressing part 20D for the thigh and a pressing part 20E for the calf. By arranging the pressing parts 20D and 20E in this way, it is possible to circulate interstitial fluid, lymph fluid, and venous blood while sitting.

[0094] The above is the description of the fifth embodiment. In the massage device 100D of the fifth embodiment, the subject can circulate interstitial fluid, lymph fluid, and venous blood while sitting on a chair. Also, in the massage device 100D, the subject can set the part where they can freely confirm the effect of the massage.

[0095] The above is the description of the massage device according to this embodiment. Note that the technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. In addition, within the scope not departing from the spirit of the present invention, it is possible to appropriately replace the components in the above embodiment with well-known components, and the above-described embodiments may be appropriately combined.

[0096] (Example) Next, an example of an experiment conducted to verify the effectiveness of the massage device of the present disclosure will be described.

[0097] FIG. 15 shows an example of the massage device used in this embodiment. This massage device includes a sleeve composed of four airbags, a pressure sensor for measuring the pressure of each part, and sensors for electrical impedance tomography provided on the thigh and calf parts. Sixteen electrodes are arranged on each sensor for electrical impedance tomography.

[0098] Using a healthy male (age: 30 years) as the subject, imaging of the reflux of interstitial fluid, lymphatic fluid, and venous blood in muscles and fat was performed during massage by the intermittent pneumatic compression (IPC) mechanism using the massage device of the present invention. The adjacent method was used for electrical impedance tomography measurement. Also, the time change of the pressure in each airbag was recorded. A current of 1 mA was applied to the calf and thigh of the subject, and the voltage was measured to perform image reconstruction by the above method. Specifically, conductivity distribution images of the calf and thigh were reconstructed.

[0099] FIG. 16 shows the change in the pressure of each airbag during massage. The vertical axis in FIG. 16 is force (N), and the horizontal axis is time (s). S1 is the pressure of the airbag 1 (the first airbag) in FIG. 15. S2 is the pressure of the airbag 2 (the second airbag) in FIG. 15. S3 is the pressure of the airbag 3 (the third airbag) in FIG. 15. S4 is the pressure of the airbag 4 (the fourth airbag) in FIG. 15. As shown in FIG. 16, the massage controls the air pressure of the four airbags in one cycle in terms of time, and the air pressure of the four airbags is also controlled spatially from the erasure side (the toe side) toward the thigh to perform intermittent pneumatic compression.

[0100] Figure 17 shows the temporal changes in the conductivity distribution of the cross-section of the left leg of the subject obtained by electrical impedance tomography measurement during massage, as seen from the head side. In this massage using the intermittent pneumatic compression (IPC) mechanism, since the pressure changes of each airbag in FIG. 16 have a time lag from the distal side toward the thigh, interstitial fluid, lymphatic fluid, and venous blood gradually reflux from the distal side toward the thigh, and this electrical impedance tomography sensor can capture the spatial and temporal changes in this reflux as the spatial and temporal changes in the region size and color depth of conductivity. Incidentally, it is known that interstitial fluid, lymphatic fluid, and venous blood are ionic liquids and have a higher conductivity than fat, muscle, and bone. Specifically, in the case of this subject (without particularly paying attention to the blue position in the upper left, which is the tibia), until around 11 seconds, the conductivity around the gastrocnemius muscle (the posterior muscle) gradually increases. Around 16 seconds, the increase in conductivity is not only around the gastrocnemius muscle but also around the soleus muscle (the muscle near the lower center). After that, around 21 seconds, the conductivity around the gastrocnemius muscle and soleus muscle slightly decreases, and the conductivity around the posterior tibial muscle (the muscle near the blue tibia in the upper left) slightly increases. That is, the time and spatial position of the circulation of interstitial fluid, lymphatic fluid, and venous blood can be grasped. Figure 18 shows the temporal changes in the conductivity distribution of the thigh of the left leg of the subject obtained by electrical impedance tomography measurement during massage, as seen from the head side. Particularly in this thigh region, an image is shown for the time up to 21 seconds. However, from the tibia where the massage is being performed to the thigh, the circulation of interstitial fluid, lymphatic fluid, and venous blood has not occurred yet, and particularly at this time, there are no significant changes in the image. However, as will be described later, it can be seen that after about 170 seconds, the circulation of interstitial fluid, lymphatic fluid, and venous blood has reached the thigh from the tibia where the massage is being performed. As shown in FIGS. 17 and 18, it was shown that by continuing the massage, spatial and temporal changes occur in the conductivity distribution of the tibia and thigh regions. Also, differences were observed in the spatial and temporal changes in the conductivity distribution between the tibia and thigh regions. As described above, it has been shown that the massage device of the present disclosure has sufficient performance to detect the physiological responses of interstitial fluid, lymph fluid, and venous blood reflux in muscles and fat during massage. It has been verified through experiments on the subject that the reflux of interstitial fluid, lymph fluid, and venous blood in the reconstructed image can be sufficiently identified.

[0101] Furthermore, the spatial average conductivity <σ> was defined to quantify the magnitude of conductivity change during massage and to evaluate in detail the reflux of interstitial fluid, lymph fluid, and venous blood. FIG. 19 shows the relationship between the spatial average conductivity <σ> in the calf, the pressure of each airbag, and time. The horizontal axis of FIG. 19 represents time (s), the left vertical axis of FIG. 19 represents the spatial average conductivity, and the right vertical axis represents force (N). td-EIT indicates the spatial average conductivity <σ> in the calf. C1 in FIG. 19 represents the pressure of the first airbag. C2 in FIG. 19 represents the pressure of the second airbag. C3 in FIG. 19 represents the pressure of the third airbag. C4 in FIG. 19 represents the pressure of the fourth airbag. Linear Fitting shows the result of linearly approximating the spatial average conductivity <σ> (td-EIT). In the calf, compared with the periodic waveform of the air pressure, the spatial average conductivity <σ> increases with a long period and then shows a constant tendency. Each time one cycle of the air pressure ends, reflux of interstitial fluid, lymph fluid, and venous blood is observed. In particular, in the case of this subject, before 260 seconds, the spatial average conductivity <σ> gradually increases while repeating a gentle cycle, and after 260 seconds, the spatial average conductivity <σ> gradually becomes constant while repeating a gentle cycle, indicating that sufficient reflux was achieved at about 260 seconds.

[0102] Figure 20 shows the relationship between the spatial average conductivity <σ> in the thigh, the pressure in each chamber, and time. The horizontal axis in Figure 20 represents time (s), the left vertical axis in Figure 20 represents the spatial average conductivity, and the right vertical axis represents force (N). The spatial average conductivity <σ> shown by td-EIT represents the spatial average conductivity in the calf. C1 in Figure 20 represents the pressure of the first airbag. C2 in Figure 20 represents the pressure of the second airbag. C3 in Figure 20 represents the pressure of the third airbag. C4 in Figure 20 represents the pressure of the fourth airbag. In the thigh, unlike the calf where massage is being performed, as time passes, it is observed that the spatial average conductivity <σ> tends to increase and become constant without a period. In the case of this subject, until about 60 seconds, there is no circulation of interstitial fluid, lymphatic fluid, and venous blood from the calf where massage is being performed to the thigh yet, and there is no significant change especially at this time. After 60 seconds, the spatial average conductivity <σ> gradually increases, rapidly increases at about 150 seconds, and then becomes constant after 170 seconds, indicating that the reflux of interstitial fluid, lymphatic fluid, and venous blood due to calf massage is sufficient in about 170 seconds. Note that the spatial average conductivity is the conductivity obtained by spatially averaging the conductivity distribution obtained by electrical impedance tomography.

[0103] From the above, it was confirmed that according to the massage device of the present disclosure, it is possible to measure the temporal and spatial changes in the distribution of interstitial fluid, lymphatic fluid, and venous blood in the living body due to massage.

Explanation of Signs

[0104] 1 Living body measurement unit, 2 Contour estimation unit, 3 Jacobian matrix calculation unit, 4 Electrical property distribution calculation unit, 10 Sensor for electrical impedance tomography, 20 Pressing unit, 21 Airbag, 22 Flow path, 25 Pressing control unit, 40 Electrical control unit, 42 Electrical wire bundle, 50 Measurement and calculation unit 50, 100 Massage device

Claims

1. A plurality of pressing parts that press against the subject, An in-vivo measurement unit that measures changes in the subject's biological information due to pressing, A Jacobian matrix calculation unit, An electrical property distribution calculation unit, A pressing control unit, Comprising, The in-vivo measurement unit includes two or more electrical impedance tomography sensors, and the electrical impedance tomography sensors include four or more electrodes. At least one of the plurality of pressing parts is provided between the electrical impedance tomography sensors. The in-vivo measurement unit measures changes in the distribution of interstitial fluid, lymphatic fluid, and venous blood. The electrical impedance tomography sensors are arranged near the pressing parts. The in-vivo measurement unit applies a current or a potential difference between the electrodes. When applying the current, it measures the potential difference and phase based on a current application voltage measurement pattern. When applying the potential difference between the electrodes, it measures the current and phase based on a voltage application current measurement pattern. The Jacobian matrix calculation unit calculates the Jacobian matrix of the subject based on a predetermined current application voltage measurement pattern or voltage application current measurement pattern, mesh coordinates obtained by dividing the contour of the subject, and the coordinates of each electrode. The electrical property distribution calculation unit calculates the electrical property distribution, which is the biological information, from the Jacobian matrix of the subject calculated by the Jacobian matrix calculation unit and the potential difference and phase or current and phase measured by the in-vivo measurement unit. The pressing control unit is a massage device that controls the pressure of each pressing part based on the electrical property distribution so that interstitial fluid, lymphatic fluid, and venous blood can circulate.

2. The massage device according to claim 1, wherein the pressing part consists of one airbag.

3. The massage device according to claim 1 or 2, wherein the pressing part consists of two or more airbags, and each airbag can apply a different pressure.

4. The massage device according to claim 1 or 2, wherein the electrodes are arranged at equal intervals.

5. The massage device according to claim 1, wherein in the Jacobian matrix calculation unit, the Jacobian matrix is calculated using machine learning.

6. The plurality of pressing parts are arranged at intervals in the longitudinal direction of the affected part of the subject between the electrical impedance tomography sensors. When the temporal change in the electrical property distribution is smaller than a predetermined value, the pressing control unit controls the pressure of the pressing part adjacent to the electrical impedance tomography sensor that has obtained the electrical property distribution with a small temporal change so that interstitial fluid, lymphatic fluid, and venous blood can circulate. The massage device according to claim 1.

7. The pressing part is composed of two or more airbags arranged in the circumferential direction of the affected part of the subject, and different pressures can be applied to each airbag. When the temporal change in the electrical property distribution is smaller than a predetermined value, the pressing control unit controls the pressure of each airbag in the pressing part adjacent to the electrical impedance tomography sensor that has obtained the electrical property distribution with a small temporal change so that interstitial fluid, lymphatic fluid, and venous blood can circulate. The massage device according to claim 1.

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