Wearable device

Abstract

A wearable device according to the present disclosure comprises: a holding body; a band body; and a first application electrode, a second application electrode, a first detection electrode, and a second detection electrode that are held by the holding body in a state of being exposed to an inner surface of the holding body, the inner surface disposed so as to face the surface of an arm. In the longitudinal direction, an electrode arrangement region of the holding body has a length of 1 / 3 or less of the total length of the wearable device. The first application electrode, the second application electrode, the first detection electrode, and the second detection electrode are disposed in a prescribed positional relationship.

Description

Wearable devices

[0001] The present disclosure relates to wearable devices.

[0002] Wearable devices that can be attached to a biological surface and have electrodes on a surface that comes into contact with the biological surface have been known. Patent Document 1 discloses a biological information measuring device as this type of wearable device. The biological information measuring device described in Patent Document 1 includes a case that houses a device main body including a biological information detection unit that detects a user's biological information, a band that attaches the case to the user's arm, and two electrodes provided on the surface of the band that comes into contact with the user's body.

[0003] JP 2016-198471 A

[0004] In the case of a wearable device that can be worn on the arm so that multiple electrodes are in contact with the surface of the arm, the distance between the multiple electrodes attached to the band may change due to arm edema, which may cause variations in the biological information measured by the wearable device and reduce measurement accuracy.

[0005] The present disclosure aims to provide a wearable device that can be worn on the surface of a living arm, in which the distance between multiple electrodes that are used in contact with the surface of the arm is less likely to change due to arm edema.

[0006] A wearable device according to a first aspect of the present disclosure provides: (1) a wearable device wearable on the surface of a living body's arm, comprising: a holder for holding a substrate; a band connected to the holder, extending from the holder so as to define the longitudinal direction of the wearable device, and arranged along the surface of the arm so that the longitudinal direction is along the circumferential direction of the arm, thereby being wearable on the arm; and a first application electrode and a second application electrode capable of applying a voltage to the arm, and a first detection electrode and a second detection electrode capable of detecting a voltage or current applied between the first application electrode and the second application electrode, which are held by the holder in a state exposed on an inner surface of the holder arranged opposite the surface of the arm; the holder has an electrode arrangement region that is continuous in the longitudinal direction, in which the first application electrode, the second application electrode, the first detection electrode, and the second detection electrode are arranged, and the electrode arrangement region has a length in the longitudinal direction that is one-third or less of the overall length of the wearable device; and in a plan view of the wearable device seen from the inner surface side of the holder, the electrode arrangement region has a first region, a second region, a third region, and a fourth region divided by a first intermediate line of the holder in the longitudinal direction and a second intermediate line in a width direction perpendicular to the longitudinal direction, the first region and the third region are arranged on one side of the first intermediate line in the longitudinal direction, and the first region and the second region are arranged on one side of the second intermediate line in the width direction, the first application electrode, the second application electrode, the first detection electrode, and the second detection electrode are arranged in different regions of the first region, the second region, the third region, and the fourth region, respectively; A wearable device that satisfies the following inequalities when the shortest distance between the first application electrode and the first detection electrode is "L1a," the shortest distance between the second application electrode and the second detection electrode is "L1b," the shortest distance between the first application electrode and the second application electrode is "L2a," and the shortest distance between the first detection electrode and the second detection electrode is "L2b." L2a>L1a, and L2a>L1b, and L2b>L1a, and L2b>L1b

[0007] A wearable device according to one embodiment of the present disclosure is (2) the wearable device described in (1) above, in which, in the plan view, the outer shape of the holder is a substantially rectangular shape having two sides along the longitudinal direction and four corners, and in the plan view, the first application electrode, the second application electrode, the first detection electrode, and the second detection electrode are arranged near different corners of the four corners of the holder.

[0008] A wearable device according to one embodiment of the present disclosure is the wearable device described in (1) or (2) above, wherein: (3) the first application electrode is arranged in the first region; the first detection electrode is arranged in the third region; and the polarity of the first application electrode relative to the second application electrode and the polarity of the first detection electrode relative to the second detection electrode are the same.

[0009] A wearable device according to one embodiment of the present disclosure is (4) the wearable device according to (3) above, in which, in the planar view, the separation distance along the longitudinal direction between the first applying electrode and the second applying electrode is 6 to 40 mm.

[0010] A wearable device according to one embodiment of the present disclosure is (5) the wearable device described in (3) or (4) above, in which, in the planar view, the first applying electrode and the first detecting electrode are arranged so that at least a portion of each electrode overlaps the other electrode in the longitudinal direction.

[0011] A wearable device according to one embodiment of the present disclosure is (6) the wearable device according to any one of (3) to (5) above, wherein, in the planar view, the second applying electrode and the second detecting electrode are arranged so that at least a portion of each electrode overlaps the other electrode in the longitudinal direction.

[0012] A wearable device according to one embodiment of the present disclosure is (7) the wearable device according to any one of (3) to (6) above, wherein, in the planar view, the first applying electrode and the second applying electrode are arranged so that at least a portion of each electrode overlaps with each other in the width direction.

[0013] A wearable device according to one embodiment of the present disclosure is (8) a wearable device according to any one of (3) to (7) above, wherein, in the planar view, the first detection electrode and the second detection electrode are arranged so that at least a portion of each electrode overlaps the other electrode in the width direction.

[0014] A wearable device according to one embodiment of the present disclosure is (9) the wearable device according to any one of (1) to (8) above, wherein, in the planar view, the first application electrode, the second application electrode, the first detection electrode, and the second detection electrode are arranged such that a first line segment forming the shortest distance "L2b" between the first detection electrode and the second detection electrode intersects with a second line segment forming the shortest distance "L2a" between the first application electrode and the second application electrode.

[0015] A wearable device according to one embodiment of the present disclosure includes: (10) an area of ​​a contact surface of each of the first applying electrode, the second applying electrode, the first detecting electrode, and the second detecting electrode that faces the surface of the arm is 50 to 200 mm ２ The wearable device according to any one of (1) to (9) above,

[0016] A wearable device according to one embodiment of the present disclosure is (11) the wearable device according to any one of (1) to (10) above, wherein the protrusion height of each of the first applying electrode, the second applying electrode, the first detecting electrode, and the second detecting electrode from the inner surface of the holder is 0.1 to 5 mm.

[0017] A wearable device according to one embodiment of the present disclosure is (12) the wearable device according to any one of (1) to (11) above, comprising a detection unit held by the holder and capable of detecting biometric information other than electrical characteristics of the living body, the holder being provided with a detection window used for detecting the biometric information by the detection unit, and the detection window being positioned in a position surrounded by the first application electrode, the second application electrode, the first detection electrode, and the second detection electrode in the planar view.

[0018] A wearable device according to one embodiment of the present disclosure is (13) the wearable device described in (12) above, wherein the detection unit includes a first light-emitting unit and a second light-emitting unit capable of emitting light of different wavelengths, and a light-receiving unit capable of receiving light emitted from the first light-emitting unit and the second light-emitting unit and reflected from the living body.

[0019] A wearable device according to one embodiment of the present disclosure is the wearable device described in (13) above, wherein (14) the first light-emitting unit comprises two first light-emitting bodies arranged in positions sandwiching the light-receiving unit in the longitudinal direction in the planar view, and the second light-emitting unit comprises two second light-emitting bodies arranged in positions sandwiching the light-receiving unit in the width direction in the planar view.

[0020] A wearable device according to one embodiment of the present disclosure is the wearable device described in (13) above, wherein (15) the first light-emitting unit comprises two first light-emitting bodies arranged in a position sandwiching the light-receiving unit in one of the longitudinal direction and the width direction in the planar view, and the second light-emitting unit comprises two second light-emitting bodies arranged in a position sandwiching the light-receiving unit in the one direction in the planar view and arranged in a row with the two first light-emitting bodies along the one direction.

[0021] According to the present disclosure, it is possible to provide a wearable device that can be worn on the surface of a living arm, in which the distance between multiple electrodes that are used in contact with the surface of the arm is less likely to change due to arm edema.

[0022] 4 is a perspective view of a wearable device according to an embodiment of the present disclosure, showing a state in which a band body is worn; FIG. 5 is a perspective view of the wearable device shown in FIG. 1, seen from a different viewpoint than FIG. 1; FIG. 6 is a side view of the wearable device shown in FIG. 1, showing a state in which the band body is unfolded; FIG. 7 is a view showing a state in which the wearable device shown in FIG. 1 is worn on the wrist of a user; FIG. 8 is a cross-sectional view taken along line II in FIG. 4; FIG. 9 is a plan view of the wearable device, seen from the inner surface side of the holder shown in FIG. 1; FIG. 10 is a diagram showing a modified example of the arrangement of the four electrodes shown in FIG. 6; FIG. 11 is a diagram showing a modified example of the configuration of the detection unit shown in FIG. 6; FIG. 12 is a diagram showing another modified example of the arrangement of the four electrodes shown in FIG. 6; FIG. 13 is a diagram showing a modified example of the holder shown in FIG. 1;

[0023] Hereinafter, an embodiment of a wearable device according to the present disclosure will be illustrated and described with reference to the drawings. In each drawing, the same components are denoted by the same reference numerals.

[0024] 1 and 2 are perspective views of a wearable device 100 as one embodiment of a wearable device according to the present disclosure. The wearable device 100 is configured to be wearable on the surface of a user's arm as a living body. As shown in FIGS. 1 and 2 , the wearable device 100 includes a holder 1, a band 2, a substrate 3, and four electrodes 4. The four electrodes 4 are a first application electrode 5a, a second application electrode 5b, a first detection electrode 6a, and a second detection electrode 6b. Hereinafter, for convenience of explanation, when there is no need to particularly distinguish between the first application electrode 5a, the second application electrode 5b, the first detection electrode 6a, and the second detection electrode 6b, they may be simply referred to as "electrodes 4."

[0025] Fig. 3 is a side view of the wearable device 100. Figs. 1 and 2 show the state in which the band body 2 is worn on the surface of the user's arm along the circumferential direction of the arm. In contrast, Fig. 3 shows the unfolded state of the band body 2, in which the band body 2 is extended linearly from the holder 1. Fig. 4 is a diagram showing the state in which the wearable device 100 is worn on the wrist Y of the user's arm X. Fig. 5 is a cross-sectional view taken along line II in Fig. 4.

[0026] First, a method of using the wearable device 100 will be described with reference to FIGS.

[0027] 4 and 5 , the wearable device 100 is configured to be usable by being wrapped around a user's arm X. More specifically, the wearable device 100 is attached to the arm X by extending the band body 2 along the circumferential direction E of the user's arm X and wrapping the band body 2 around the arm X.

[0028] 4 and 5 show an example in which the wearable device 100 is wrapped around the wrist Y of the user's arm X with the band body 2, but the attachment position of the wearable device 100 is not limited to the wrist Y of the arm X. For example, the wearable device 100 may be used by being wrapped around the forearm of the user's arm X with the band body 2. Below, an example of a method of using the wearable device 100 by wrapping it around the wrist Y of the user's arm X will be described.

[0029] 4 and 5 , wearable device 100 can acquire biometric information while being wrapped around wrist Y of a user's arm X. More specifically, wearable device 100 can acquire biometric information based on electrical characteristics of a living body. However, wearable device 100 may also be able to acquire other biometric information that is not based on electrical characteristics of a living body, in addition to biometric information based on electrical characteristics of a living body.

[0030] Examples of bioinformation based on the electrical characteristics of a living organism include bioelectrical impedance detected by passing electricity through the living organism, electrocardiographic information related to cardiac activity obtained by detecting electrical signals flowing through the living organism, etc. The wearable device 100 of this embodiment is configured to be able to acquire bioelectrical impedance as bioinformation based on the electrical characteristics of a living organism.

[0031] Examples of other biological information that is not based on the electrical characteristics of a living body include pulse wave information, blood pressure information, activity level information, and body temperature information. These are biological information that can be obtained without passing electricity through a living body or detecting electrical signals flowing through a living body. As will be described in detail later, the wearable device 100 of this embodiment is configured to be able to acquire pulse wave information as another type of biological information that is not based on the electrical characteristics of a living body.

[0032] In this way, the wearable device 100 of this embodiment is worn around the arm X of the user, and is therefore capable of acquiring bioelectrical impedance and pulse wave information of the user.

[0033] The wearable device 100 of this embodiment can measure the amount of moisture in the user's wrist Y by acquiring bioelectrical impedance from the user's wrist Y. It is known that a decline in cardiac function in a living body can cause edema, in which moisture accumulates on or under the skin. The wearable device 100 can monitor the amount of moisture in the wrist Y of a user, such as a heart disease patient, and thereby detect a decline in the user's cardiac function early.

[0034] Furthermore, the wearable device 100 of this embodiment can monitor the user's heart rate in addition to the above-mentioned moisture content of the user by acquiring pulse wave information from the user's wrist Y. Therefore, a decline in the user's cardiac function can be considered from the perspective of fluctuations in heart rate as well as fluctuations in moisture content.

[0035] The wearable device 100 may be constantly attached to the user for a certain period of time, such as several hours or several days. In this manner, the state of the user's cardiac function can be constantly monitored. This allows for early detection of a decline in the user's cardiac function. However, the wearable device 100 may also be temporarily attached to the user for the purpose of understanding the state of the user's cardiac function at a predetermined time.

[0036] The holder 1 holds a substrate 3 and a plurality of electrodes 4. The band body 2 is connected to the holder 1 and extends from the holder 1 so as to define a longitudinal direction A of the wearable device 100. In other words, the longitudinal direction A of the wearable device 100 is the direction in which the band body 2 extends from the holder 1. As shown in FIG. 5 , the band body 2 can be worn on the user's arm X by being arranged along the surface Z of the arm X so that the longitudinal direction A is along the circumferential direction E of the arm X. By wearing the band body 2 on the user's arm X as described above, the wearable device 100 can be worn on the surface Z of the user's arm X.

[0037] As described above, the substrate 3 is held by the holder 1. The substrate 3 may be housed, for example, in the internal space 1a of the housing serving as the holder 1. Various electronic components are mounted on the substrate 3. The control unit 50 of the wearable device 100 may be configured to include, for example, the substrate 3 and the various electronic components mounted on the substrate 3. The control unit 50 of the wearable device 100 may also be configured, for example, by an IC chip mounted on the substrate 3. Such a control unit 50 may be configured, for example, by a processor such as a CPU or an MPU.

[0038] The four electrodes 4 are held by the holder 1 in a state where they are exposed to an inner surface 10 of the holder 1 that faces the surface Z of the arm X. Therefore, as shown in FIGS. 4 and 5 , when the wearable device 100 is worn on the arm X of a living body, the four electrodes 4 come into contact with the surface Z of the arm X. The four electrodes 4 may be electrically connected to the control unit 50 via conductors. Of the four electrodes 4, the first application electrode 5a and the second application electrode 5b are configured to be able to apply a voltage to the arm X. Of the four electrodes 4, the first detection electrode 6a and the second detection electrode 6b are configured to be able to detect a voltage or current applied between the first application electrode 5a and the second application electrode 5b.

[0039] The wearable device 100 is capable of measuring biological information based on electrical characteristics of the living body, such as bioelectrical impedance, based on the voltage applied to the arm X by the first application electrode 5 a and the second application electrode 5 b and the voltage applied between the first application electrode 5 a and the second application electrode 5 b detected by the first detection electrode 6 a and the second detection electrode 6 b. Specifically, in the wearable device 100 of this embodiment, the control unit 50 is configured to be capable of deriving biological information based on electrical characteristics of the living body, such as bioelectrical impedance, based on the voltage applied to the arm X by the first application electrode 5 a and the second application electrode 5 b and the voltage applied between the first application electrode 5 a and the second application electrode 5 b detected by the first detection electrode 6 a and the second detection electrode 6 b.

[0040] However, the wearable device 100 does not have to be configured to be capable of measuring biological information based on electrical characteristics of a living body, such as bioelectrical impedance. The wearable device 100 may be configured to be capable of transmitting, to an external device, for example, the voltage applied to the arm X by the first application electrode 5 a and the second application electrode 5 b, and the voltage applied between the first application electrode 5 a and the second application electrode 5 b, which is detected by the first detection electrode 6 a and the second detection electrode 6 b, via a communication unit 51 described later. The biological information based on electrical characteristics of a living body, such as bioelectrical impedance, may be derived, for example, in the external device.

[0041] The holder 1 has an electrode arrangement area AE in which the first application electrode 5a, the second application electrode 5b, the first detection electrode 6a, and the second detection electrode 6b are arranged. The electrode arrangement area AE is a continuous area in the longitudinal direction A. That is, the range of the electrode arrangement area AE in the longitudinal direction A extends from one end of the four electrodes 4 in the longitudinal direction A to the other end of the four electrodes 4 in the longitudinal direction A. As shown in FIG. 3 , the electrode arrangement area AE has a length in the longitudinal direction A that is equal to or less than one-third of the total length D1 of the wearable device 100. That is, the length D2 of the electrode arrangement area AE in the longitudinal direction A is equal to or less than one-third of the total length D1 of the wearable device 100. The length D2 of the electrode arrangement area AE in the longitudinal direction A refers to the maximum length of the electrode arrangement area AE in the longitudinal direction A. 4 and 5 , when the wearable device 100 is worn on the arm X so that the holder 1 covers a portion Z1 of the surface Z of the arm X that is on the back of the hand, the electrode placement area AE is more likely to fit within the range of the portion Z1 of the surface Z of the arm X. Furthermore, even when the wearable device 100 is worn on the arm X so that the holder 1 covers a portion of the surface Z of the arm X that is on the palm side, the electrode placement area AE is more likely to fit within the portion of the surface Z of the arm X that is on the palm side. This makes it less likely that the distances between the four electrodes 4 will fluctuate even if edema occurs in the arm X of a living subject wearing the wearable device 100. Therefore, it is possible to prevent variation in bioinformation based on the electrical characteristics of the living subject, such as bioelectrical impedance, measured by the wearable device 100, due to edema in the arm X. As a result, it is possible to prevent a decrease in the measurement accuracy of bioinformation based on the electrical characteristics of the living subject measured using the wearable device 100.

[0042] From the viewpoint of placing the electrode placement area AE within the range of the back-side portion Z1 of the surface Z of the arm X or the range of the palm-side portion, it is preferable that the length D2 of the longitudinal direction A of the electrode placement area AE be 1 / 4 or less of the total length D1 of the wearable device 100, and it is more preferable that it be 1 / 5 or less of the total length D1 of the wearable device 100.

[0043] FIG. 6 is a plan view of the wearable device 100 as seen from the inner surface 10 side of the holder 1. Hereinafter, the plan view shown in FIG. 6 will be simply referred to as the "plan view." As shown in FIG. 6 , in the plan view, the electrode arrangement area AE has a first area AE1, a second area AE2, a third area AE3, and a fourth area AE4, which are divided by a first midpoint M1 of the holder 1 in the longitudinal direction A and a second midpoint M2 of the holder 1 in the width direction B perpendicular to the longitudinal direction A. The "first midpoint M1 of the holder 1" refers to an imaginary line that passes through a midpoint P1 of the holder 1 in the longitudinal direction A and is parallel to the width direction B of the holder 1 perpendicular to the longitudinal direction A in the plan view. The "midpoint P1 of the holder 1 in the longitudinal direction A" refers to the midpoint of the maximum length D3 of the holder 1 in the longitudinal direction A. The "second midpoint M2 of the holder 1" refers to an imaginary line that, in a plan view, passes through the midpoint P2 of the holder 1 in the width direction B and is parallel to the longitudinal direction A. The "midpoint P2 of the holder 1 in the width direction B" refers to the midpoint of the maximum length D4 of the holder 1 in the width direction B.

[0044] The first region AE1 and the third region AE3 are disposed on one side (the left side in FIG. 6 ) of the first intermediate line M1 in the longitudinal direction A. In other words, the second region AE2 and the fourth region AE4 are disposed on the other side (the right side in FIG. 6 ) of the first intermediate line M1 in the longitudinal direction A.

[0045] Furthermore, the first region AE1 and the second region AE2 are disposed on one side (upper side in FIG. 6 ) of the second intermediate line M2 in the width direction B. In other words, the third region AE3 and the fourth region AE4 are disposed on the other side (lower side in FIG. 6 ) of the second intermediate line M2 in the width direction B.

[0046] More specifically, the first region AE1 of the electrode arrangement region AE is a partial region of the electrode arrangement region AE that, in a plan view (see FIG. 6 ), is located on one side in the longitudinal direction A (the left side in FIG. 6 ) of the first midpoint line M1 of the holder 1, and is located on one side in the width direction B (the upper side in FIG. 6 ) of the second midpoint line M2 of the holder 1. The second region AE2 of the electrode arrangement region AE is a partial region of the electrode arrangement region AE that, in a plan view (see FIG. 6 ), is located on the other side in the longitudinal direction A (the right side in FIG. 6 ) of the first midpoint line M1 of the holder 1, and is located on one side in the width direction B (the upper side in FIG. 6 ) of the second midpoint line M2 of the holder 1. The third region AE3 of the electrode arrangement region AE is a partial region of the electrode arrangement region AE that, in a plan view (see FIG. 6 ), is located on one side in the longitudinal direction A (the left side in FIG. 6 ) of the first midpoint line M1 of the holder 1, and is located on the other side in the width direction B (the lower side in FIG. 6 ) of the second midpoint line M2 of the holder 1. The fourth region AE4 of the electrode arrangement region AE is a partial region of the electrode arrangement region AE that, in a plan view (see FIG. 6 ), is located on the other side in the longitudinal direction A (the right side in FIG. 6 ) of the first midpoint line M1 of the holder 1, and is located on the other side in the width direction B (the lower side in FIG. 6 ) of the second midpoint line M2 of the holder 1.

[0047] The first application electrode 5a, the second application electrode 5b, the first detection electrode 6a, and the second detection electrode 6b are arranged so as to satisfy the following two conditions 1 and 2 in a plan view (see FIG. 6).

[0048] (Condition 1) As shown in Fig. 6 , in a plan view, the first application electrode 5a, the second application electrode 5b, the first detection electrode 6a, and the second detection electrode 6b are arranged in different regions, namely, a first region AE1, a second region AE2, a third region AE3, and a fourth region AE4. As shown in Fig. 6 , in this embodiment, the first application electrode 5a is arranged in the first region AE1, the second application electrode 5b is arranged in the second region AE2, the first detection electrode 6a is arranged in the third region AE3, and the second detection electrode 6b is arranged in the fourth region AE4. However, this arrangement is not limited to this. It is sufficient that the first application electrode 5a, the second application electrode 5b, the first detection electrode 6a, and the second detection electrode 6b are arranged in different regions, namely, the first region AE1, the second region AE2, the third region AE3, and the fourth region AE4.

[0049] Here, in the plan view shown in FIG. 6, the shortest distance between the first application electrode 5a and the first detection electrode 6a is defined as "L1a." Furthermore, in the plan view shown in FIG. 6, the shortest distance between the second application electrode 5b and the second detection electrode 6b is defined as "L1b." Furthermore, in the plan view shown in FIG. 6, the shortest distance between the first application electrode 5a and the second application electrode 5b is defined as "L2a." Furthermore, in the plan view shown in FIG. 6, the shortest distance between the first detection electrode 6a and the second detection electrode 6b is defined as "L2b." In this case, L1a, L1b, L2a, and L2b satisfy the following inequality 1.

[0050] (Condition 2) [Inequality 1] L2a>L1a, and L2a>L1b, and L2b>L1a, and L2b>L1b

[0051] As described above, by locating the electrode arrangement area AE within the back-side portion Z1 or the palm-side portion of the surface Z of the arm X, the distance between the four electrodes 4 is less likely to change even if edema occurs in the arm X of a living body wearing the wearable device 100. On the other hand, by locating the electrode arrangement area AE within the back-side portion Z1 or the palm-side portion of the surface Z of the arm X, the distance between the four electrodes 4 is smaller than when the electrode arrangement area AE is not within the back-side portion Z1 or the palm-side portion of the surface Z of the arm X. In such a case, the detected value of the voltage applied between the first application electrode 5a and the second application electrode 5b detected by the first detection electrode 6a and the second detection electrode 6b is likely to be small, which may make it impossible to accurately measure changes due to edema in biological information based on the electrical characteristics of the living body, such as bioelectrical impedance.

[0052] In contrast, in the wearable device 100, the first application electrode 5a, the second application electrode 5b, the first detection electrode 6a, and the second detection electrode 6b are arranged in a plan view (see FIG. 6 ) to satisfy the above-mentioned two conditions 1 and 2. As a result, even when the wearable device 100 is worn on the arm X, the electrode arrangement area AE is within the back-side portion Z1 or the palm-side portion of the surface Z of the arm X of a living user, so that the shortest distance L2a between the first application electrode 5a and the second application electrode 5b and the shortest distance L2b between the first detection electrode 6a and the second detection electrode 6b can be ensured to be large within that range. Furthermore, the shortest distance L1a between the first application electrode 5a and the first detection electrode 6a and the shortest distance L1b between the second application electrode 5b and the second detection electrode 6b can be reduced. Therefore, even when the wearable device 100 is worn on the arm X so that the electrode arrangement area AE is within the range of the back-side portion Z1 or the range of the palm-side portion of the surface Z of the user's arm X as a living body, the detection value of the voltage applied between the first application electrode 5a and the second application electrode 5b detected by the first detection electrode 6a and the second detection electrode 6b can be increased. As a result, the resolution of the detection value of the voltage applied between the first application electrode 5a and the second application electrode 5b can be increased, and it becomes possible to accurately measure, for example, changes due to edema in biological information based on the electrical characteristics of the living body, such as bioelectrical impedance.

[0053] Furthermore, as in this embodiment, it is preferable that the first application electrode 5 a and the first detection electrode 6 a are located on one side of the first intermediate line M1 in the longitudinal direction A (the left side in FIG. 6 ), and the second application electrode 5 b and the second detection electrode 6 b are located on the other side of the first intermediate line M1 in the longitudinal direction A (the right side in FIG. 6 ). This arrangement makes it easier to detect changes in bioinformation based on the electrical characteristics of the living body in a cross section perpendicular to the longitudinal direction of the arm X. In other words, changes in bioelectrical impedance due to edema of the arm X, which changes the thickness of the arm X, can be detected with greater accuracy.

[0054] More specifically, when the first application electrode 5a is arranged in the first region AE1 or the third region AE3, the second application electrode 5b is preferably arranged in the second region AE2 or the fourth region AE4. Furthermore, when the first application electrode 5a is arranged in the second region AE2 or the fourth region AE4, the second application electrode 5b is preferably arranged in the first region AE1 or the third region AE3.

[0055] Furthermore, when the first detection electrode 6a is arranged in the first region AE1 or the third region AE3, the second detection electrode 6b is preferably arranged in the second region AE2 or the fourth region AE4. Furthermore, when the first detection electrode 6a is arranged in the second region AE2 or the fourth region AE4, the second detection electrode 6b is preferably arranged in the first region AE1 or the third region AE3.

[0056] FIG. 6 shows an example of the above-mentioned arrangement, in which the first application electrode 5a is arranged in a first area AE1, the second application electrode 5b is arranged in a second area AE2, the first detection electrode 6a is arranged in a third area AE3, and the second detection electrode 6b is arranged in a fourth area AE4.

[0057] Furthermore, as shown in FIG. 6 , the first application electrode 5a and the first detection electrode 6a located on one side of the first intermediate line M1 in the longitudinal direction A (the left side in FIG. 6 ) preferably have the same polarity. Specifically, the polarity of the first application electrode 5a relative to the second application electrode 5b and the polarity of the first detection electrode 6a relative to the second detection electrode 6b are preferably the same. By arranging the first application electrode 5a, the second application electrode 5b, the first detection electrode 6a, and the second detection electrode 6b so as to have such a polarity relationship, the positive and negative polarities of the voltages applied by the first application electrode 5a and the second application electrode 5b and the voltages detected by the first detection electrode 6a and the second detection electrode 6b across the first application electrode 5a and the second application electrode 5b are the same. This facilitates the process of measuring biological information based on the electrical characteristics of a living organism.

[0058] In this embodiment, the first application electrode 5 a and the first detection electrode 6 a are positive electrodes, and the second application electrode 5 b and the second detection electrode 6 b are negative electrodes, but this configuration is not limiting. The first application electrode 5 a and the first detection electrode 6 a may be negative electrodes, and the second application electrode 5 b and the second detection electrode 6 b may be positive electrodes.

[0059] The wearable device 100 of this embodiment will be described in further detail below.

[0060] The wearable device 100 of this embodiment comprises a holder 1, a band 2, a substrate 3, four electrodes 4, a control unit 50, a communication unit 51, a detection unit 52, a rechargeable battery 53, and a charging terminal 54.

[0061] <Holder 1> The holder 1 of this embodiment holds a substrate 3, four electrodes 4, a control unit 50, a communication unit 51, a detection unit 52, a rechargeable battery 53, and a charging terminal 54. Specifically, the holder 1 of this embodiment is a rectangular, box-shaped insulating housing made of resin that defines an internal space 1a. The substrate 3, the control unit 50, the communication unit 51, the detection unit 52, and the rechargeable battery 53 are housed in the internal space 1a. The four electrodes 4 and the charging terminal 54 are exposed on the inner surface 10 of the holder 1. The four electrodes 4, the detection unit 52, and the charging terminal 54 of this embodiment are fixed to the substrate 3 held by the holder 1.

[0062] More specifically, the holder 1 of this embodiment includes a top wall 1b, a bottom wall 1c, and a side wall 1d. The internal space 1a of the holder 1 is defined by the top wall 1b, the bottom wall 1c, and the side wall 1d. The top wall 1b and the bottom wall 1c are arranged opposite each other in a thickness direction C that is perpendicular to the longitudinal direction A and the width direction B. The inner surface 10 of the holder 1 is defined by the bottom wall 1c. The outer surface 11 of the holder 1 opposite the inner surface 10 is defined by the top wall 1b. The periphery of the internal space 1a in the longitudinal direction A and the width direction B is defined by the side wall 1d. More specifically, the side wall 1d of this embodiment includes two wall portions opposing each other in the longitudinal direction A and two wall portions opposing each other in the width direction B. The outer surfaces of the two wall portions of the side wall 1d opposing each other in the longitudinal direction A are provided with connecting portions 1e that can connect the band 2. Each connecting portion 1e of this embodiment is composed of two support protrusions that rotatably support the band receiving member 14. An insertion hole through which the band body 2 is inserted is formed in the band receiving member 14. The band body 2 of this embodiment is configured to be attachable to the band receiving member 14 using the insertion hole of the band receiving member 14. Therefore, the band body 2 can be indirectly attached to the holder 1 via the band receiving member 14. However, the attachment configuration for attaching the band body 2 to the holder 1 is not limited to the configuration of this embodiment.

[0063] The four electrodes 4 of this embodiment are held by the holder 1 so as to be exposed to the outside from the inner surface 10 of the holder 1. Specifically, the four electrodes 4 of this embodiment are exposed to the outside from the bottom wall portion 1c so as to protrude from the bottom surface of the bottom wall portion 1c, which is the inner surface 10 of the holder 1. The protruding height H of each of the four electrodes 4 from the inner surface 10 of the holder 1 will be described later (see FIG. 5 ).

[0064] The holder 1 is also provided with a detection window 1c1 that is used for detecting biological information by a detection unit 52, which will be described later. The detection window 1c1 is arranged so as to be surrounded by four electrodes 4 in a plan view (see FIG. 6). Specifically, the detection window 1c1 is arranged at a position surrounded by the first application electrode 5a, the second application electrode 5b, the first detection electrode 6a, and the second detection electrode 6b in a plan view (see FIG. 6).

[0065] More specifically, the detection window 1c1 of this embodiment is formed in the bottom wall 1c. The detection window 1c1 of this embodiment is a transparent portion that constitutes part of the bottom wall 1c. The detection unit 52 of this embodiment can detect biological information through the transparent portion serving as the detection window 1c1. The transparent portion serving as the detection window 1c1 may be made of, for example, resin. The detection window 1c1 is not limited to the transparent portion of this embodiment, and may be, for example, a through-hole that penetrates the bottom wall 1c. However, by making the detection window 1c1 a transparent portion, the detection unit 52 can be prevented from being exposed to the outside of the holder 1. This makes it possible to protect the detection unit 52. Details of the detection unit 52 will be described later.

[0066] Furthermore, in plan view (see FIG. 6 ), the holder 1 of this embodiment has a generally rectangular outer shape having two sides 12a, 12b and four corners 13a to 13d extending along the longitudinal direction A. More specifically, in plan view (see FIG. 6 ), the inner surface 10 of the holder 1 of this embodiment includes a first outer edge 10a and a second outer edge 10b that form the two sides 12a, 12b extending along the longitudinal direction A, and a third outer edge 10c and a fourth outer edge 10d that form the two sides 12c, 12d extending along the width direction B. The first corner 13a, which is one of the four corners 13a to 13d, is formed by the intersection of the first outer edge 10a and the third outer edge 10c. The second corner 13b, which is one of the four corners 13a to 13d, is formed by the intersection of the first outer edge 10a and the fourth outer edge 10d. The third corner 13c, which is one of the four corners 13a to 13d, is formed by the intersection of the second outer edge 10b and the third outer edge 10c. The fourth corner 13d, which is one of the four corners 13a to 13d, is formed by the intersection of the second outer edge 10b and the fourth outer edge 10d.

[0067] <Band 2> As described above, the band 2 is connected to the holder 1. As described above, the band 2 of this embodiment is indirectly attached to the connecting portion 1e of the holder 1 via the band receiving member 14.

[0068] 1, 2, and 5, the band body 2 of this embodiment, when wrapped around the user's arm X and worn, comprises a first locking portion 20a, a wrapping portion 20b, a second locking portion 20c, and a folded-back portion 20d. The first locking portion 20a is connected to one connecting portion 1e of the holder 1 via a band receiving member 14. The wrapping portion 20b is wrapped around the user's arm X from the first locking portion 20a and extends to the other connecting portion 1e of the holder 1. The second locking portion 20c is inserted into an insertion hole of the band receiving member 14 attached to the other connecting portion 1e of the holder 1. The folded-back portion 20d extends from the second locking portion 20c along the wrapping portion 20b. 1 and other figures, the band 2 of this embodiment further includes a binder 15 that can bind the wrapping portion 20b and the folded portion 20d together. With the band 2 of this embodiment, the lengths of the wrapping portion 20b and the folded portion 20d can be adjusted to fit the thickness of the user's arm X. In other words, the band 2 of this embodiment can be worn on the user's arm X regardless of the thickness of the user's arm X.

[0069] However, the band body 2 is not limited to the above-described configuration. The band body 2 may have other configurations as long as it is connected to the holder 1, extends from the holder 1 so as to define the longitudinal direction A of the wearable device 100, and is arranged along the surface Z of the arm X so that the longitudinal direction A is aligned with the circumferential direction E of the arm X, thereby making it possible to wear the band body 2 on the arm X. For example, the band body 2 may be configured to include two band portions that protrude from both sides of the holder 1 in the longitudinal direction A and are bound together when wrapped around the arm X.

[0070] The band body 2 of this embodiment is a flexible band-shaped body that can flexibly deform in the thickness direction F. The band body 2 of this embodiment is connected to the holder 1 so that the width direction of the band body 2, which is perpendicular to the longitudinal direction A and the thickness direction F, substantially coincides with the width direction B of the holder 1. Therefore, the band body 2 of this embodiment can be worn on the arm X by wrapping it around the arm X while deforming it in the thickness direction F. The band body 2 of this embodiment may be made of, for example, a non-conductive resin.

[0071] <Substrate 3> The substrate 3 of this embodiment forms an electronic circuit together with various electronic components mounted thereon. The substrate 3 of this embodiment is housed in the internal space 1a of the holder 1. As described above, the four electrodes 4, the detection unit 52, and the charging terminal 54 are fixed to the substrate 3 of this embodiment.

[0072] <Four Electrodes 4> The four electrodes 4 of this embodiment are composed of a pair of a first application electrode 5a and a second application electrode 5b, and a pair of a first detection electrode 6a and a second detection electrode 6b. Each of these four electrodes 4 is a dry electrode. Each of these four electrodes 4 includes conductive rubber or metal. However, the four electrodes 4 are preferably made of a metal with high conductivity, and more preferably a biocompatible metal such as titanium.

[0073] As described above, the four electrodes 4 are exposed from the inner surface 10 of the holder 1. As shown in FIG. 6 , the four electrodes 4 of this embodiment are arranged near different corners of the four corners 13a to 13d of the holder 1 in a plan view. More specifically, the first application electrode 5a of this embodiment is arranged closer to the first corner 13a relative to the other three electrodes 4. The second application electrode 5b of this embodiment is arranged closer to the second corner 13b relative to the other three electrodes 4. The first detection electrode 6a of this embodiment is arranged closer to the third corner 13c relative to the other three electrodes 4. The second detection electrode 6b of this embodiment is arranged closer to the fourth corner 13d relative to the other three electrodes 4.

[0074] In this way, the four electrodes 4 are arranged near different corners of the four corners 13a to 13d of the holder 1 in a plan view, so that the distance between the first application electrode 5a and the second application electrode 5b can be made larger, and as a result, changes due to edema in biological information based on the electrical characteristics of the living body, such as bioelectrical impedance, can be detected more accurately.

[0075] Furthermore, in a plan view (see FIG. 6 ), the separation distance (the same distance as "L2a" in this embodiment) between the first application electrode 5a and the second application electrode 5b along the longitudinal direction A is preferably 6 to 40 mm. This makes it easier to ensure a large distance between the first application electrode 5a and the second application electrode 5b in the range of the portion Z1 on the back of the hand of the surface Z of the arm X. Therefore, it becomes possible to more accurately detect changes due to edema in biological information based on the electrical characteristics of the living body, such as bioelectrical impedance, while suppressing fluctuations in the distance between the first application electrode 5a and the second application electrode 5b due to edema.

[0076] Furthermore, the area of ​​the contact surface of each of the four electrodes 4 facing the surface Z of the arm X is 50 to 200 mm ２ Specifically, the area of ​​the contact surface 5a1 of the first application electrode 5a, the area of ​​the contact surface 5b1 of the second application electrode 5b, the area of ​​the contact surface 6a1 of the first detection electrode 6a, and the area of ​​the contact surface 6b1 of the second detection electrode 6b are each preferably 50 to 200 mm ２ It is preferable that the area of ​​the contact surface is 50 mm ２ This makes it possible to prevent a situation in which the four electrodes 4 are not in contact with the surface Z of the arm X when the wearable device 100 is worn on the arm X. In addition, when the area of ​​the contact surface is 200 mm ２ In particular, the area of ​​the contact surface of each of the four electrodes 4 facing the surface Z of the arm X is 50 to 100 mm ２ It is preferable that:

[0077] Furthermore, the first application electrode 5a and the first detection electrode 6a in this embodiment are arranged so that, in a plan view (see FIG. 6), at least a portion of each electrode overlaps the other electrode in the longitudinal direction A. In other words, in this embodiment, at least a portion of the first application electrode 5a is in the same position as at least a portion of the first detection electrode 6a in the longitudinal direction A. By arranging the electrodes in this manner, it becomes easier to ensure the relationship of Inequality 1 described above.

[0078] Furthermore, in this embodiment, in plan view (see FIG. 6 ), the entire area of ​​the first detection electrode 6a overlaps with the first application electrode 5a in the longitudinal direction A. In other words, in plan view (see FIG. 6 ), the entire area of ​​the first detection electrode 6a is located within the range of the first application electrode 5a in the longitudinal direction A. By doing so, it becomes easier to ensure the relationship of Inequality 1 described above.

[0079] Furthermore, in this embodiment, the entire area of ​​the first application electrode 5a overlaps with the first detection electrode 6a in the longitudinal direction A in a plan view (see FIG. 6). In other words, the entire area of ​​the first application electrode 5a is located within the range of the first detection electrode 6a in the longitudinal direction A in a plan view (see FIG. 6). That is, in this embodiment, the first application electrode 5a and the first detection electrode 6a are arranged so that they entirely overlap with each other in the longitudinal direction A in a plan view (see FIG. 6). In this way, it becomes even easier to ensure the relationship of Inequality 1 described above.

[0080] Furthermore, the second application electrode 5b and the second detection electrode 6b of this embodiment are arranged so that, in a plan view (see FIG. 6), at least a portion of each electrode overlaps the other electrode in the longitudinal direction A. In other words, in this embodiment, at least a portion of the second application electrode 5b is in the same position as at least a portion of the second detection electrode 6b in the longitudinal direction A. By arranging the electrodes in this manner, it becomes easier to ensure the relationship of Inequality 1 described above.

[0081] Furthermore, in this embodiment, in plan view (see FIG. 6 ), the entire area of ​​the second detection electrode 6 b overlaps with the second application electrode 5 b in the longitudinal direction A. In other words, in plan view (see FIG. 6 ), the entire area of ​​the second detection electrode 6 b is located within the range of the second application electrode 5 b in the longitudinal direction A. By doing so, it becomes easier to ensure the relationship of Inequality 1 described above.

[0082] Furthermore, in this embodiment, the entire area of ​​the second application electrode 5b overlaps with the second detection electrode 6b in the longitudinal direction A in a plan view (see FIG. 6). In other words, the entire area of ​​the second application electrode 5b is located within the range of the second detection electrode 6b in the longitudinal direction A in a plan view (see FIG. 6). That is, in this embodiment, the second application electrode 5b and the second detection electrode 6b are arranged so that they entirely overlap with each other in the longitudinal direction A in a plan view (see FIG. 6). In this way, it becomes even easier to ensure the relationship of Inequality 1 described above.

[0083] Furthermore, the first application electrode 5a and the second application electrode 5b of this embodiment are arranged so that, in a plan view (see FIG. 6), at least a portion of each electrode overlaps the other electrode in the width direction B. In other words, in this embodiment, at least a portion of the first application electrode 5a is located at the same position as at least a portion of the second application electrode 5b in the width direction B. By arranging the electrodes in this manner, it becomes easier to ensure the relationship of Inequality 1 described above.

[0084] Furthermore, in this embodiment, in plan view (see FIG. 6 ), the entire area of ​​the second application electrode 5b overlaps with the first application electrode 5a in the width direction B. In other words, in plan view (see FIG. 6 ), the entire area of ​​the second application electrode 5b is located within the range of the first application electrode 5a in the width direction B. By doing so, it becomes easier to ensure the relationship of Inequality 1 described above.

[0085] Furthermore, in this embodiment, the entire area of ​​the first application electrode 5a overlaps with the second application electrode 5b in the width direction B in a plan view (see FIG. 6). In other words, the entire area of ​​the first application electrode 5a is located within the range of the second application electrode 5b in the width direction B in a plan view (see FIG. 6). That is, in this embodiment, the first application electrode 5a and the second application electrode 5b are arranged so that they entirely overlap with each other in the width direction B in a plan view (see FIG. 6). In this way, it becomes even easier to ensure the relationship of Inequality 1 described above.

[0086] Furthermore, the first detection electrodes 6a and the second detection electrodes 6b of this embodiment are arranged so that, in a plan view (see FIG. 6), at least a portion of each electrode overlaps the other electrode in the width direction B. In other words, in this embodiment, at least a portion of the first detection electrodes 6a is located at the same position as at least a portion of the second detection electrodes 6b in the width direction B. By arranging the electrodes in this manner, it becomes easier to ensure the relationship of Inequality 1 described above.

[0087] Furthermore, in this embodiment, in plan view (see FIG. 6 ), the entire area of ​​the second detection electrode 6 b overlaps with the first detection electrode 6 a in the width direction B. In other words, in plan view (see FIG. 6 ), the entire area of ​​the second detection electrode 6 b is located within the range of the first detection electrode 6 a in the width direction B. This makes it easier to ensure the relationship of Inequality 1 described above.

[0088] Furthermore, in this embodiment, the entire area of ​​the first detection electrode 6a overlaps with the second detection electrode 6b in the width direction B in a plan view (see FIG. 6). In other words, the entire area of ​​the first detection electrode 6a is located within the range of the second detection electrode 6b in the width direction B in a plan view (see FIG. 6). That is, in this embodiment, the first detection electrode 6a and the second detection electrode 6b are arranged so that they entirely overlap with each other in the width direction B in a plan view (see FIG. 6). In this way, it becomes even easier to ensure the relationship of Inequality 1 described above.

[0089] Although each of the four electrodes 4 in this embodiment has a rectangular outer shape in plan view (see FIG. 6 ), the shape is not limited to this. For example, each of the four electrodes 4 may have a circular outer shape in plan view (see FIG. 6 ).

[0090] Furthermore, in a plan view (see FIG. 6 ), the relative positional relationship between the first application electrode 5a and the first detection electrode 6a in the width direction B is the same as the relative positional relationship between the second application electrode 5b and the second detection electrode 6b in the width direction B. That is, the first application electrode 5a of this embodiment is located on one side in the width direction B (upper side in FIG. 6 ) relative to the first detection electrode 6a. The second application electrode 5b of this embodiment is also located on one side in the width direction B (upper side in FIG. 6 ) relative to the second detection electrode 6b. In other words, the first region AE1 in which the first application electrode 5a of this embodiment is arranged is located on one side in the width direction B (upper side in FIG. 6 ) relative to the third region AE3 in which the first detection electrode 6a of this embodiment is arranged. The second region AE2 in which the second application electrode 5b of this embodiment is arranged is also located on one side in the width direction B (upper side in FIG. 6 ) relative to the fourth region AE4 in which the second detection electrode 6b of this embodiment is arranged. However, as shown in Fig. 7 , the first application electrode 5a may be located on the other side in the width direction B (lower side in Fig. 7 ) relative to the first detection electrode 6a in a plan view. Similarly, the second application electrode 5b may be located on the other side in the width direction B (lower side in Fig. 7 ) relative to the second detection electrode 6b in a plan view. That is, the first application electrode 5a may be arranged in the third region AE3, and the first detection electrode 6a may be arranged in the first region AE1. Similarly, the second application electrode 5b may be arranged in the fourth region AE4, and the second detection electrode 6b may be arranged in the second region AE2.

[0091] As shown in Figure 5, the protruding height H of each of the four electrodes 4 from the inner surface 10 of the holder 1 is preferably 0.1 to 5 mm, and more preferably 0.1 to 1 mm. By making the protruding height H of the four electrodes 4 0.1 mm or more, the four electrodes can easily contact the surface Z of the arm X. Furthermore, by making the protruding height H of the four electrodes 4 5 mm or less, it is possible to prevent each electrode 4 from sinking into the surface Z of the arm X, thereby suppressing fluctuations in the contact area of ​​each electrode 4 with the surface Z of the arm X. As a result, it is possible to suppress changes in bioinformation based on the electrical characteristics of the living body, such as bioelectrical impedance, due to fluctuations in the contact area between the electrodes 4 and the surface Z of the arm X.

[0092] Furthermore, the shortest distance L1a between the first application electrode 5a and the first detection electrode 6a in a plan view (see FIG. 6) is preferably 0.5 to 15 mm, more preferably 0.5 to 10 mm. Furthermore, the shortest distance L1b between the second application electrode 5b and the second detection electrode 6b in a plan view (see FIG. 6) is also preferably 0.5 to 15 mm, more preferably 0.5 to 10 mm, and even more preferably 0.5 to 6.0 mm.

[0093] Furthermore, it is preferable that the two shortest distances L1a and L1b satisfy the relationship: 0.7×L1a≦L1b≦1.3×L1a.

[0094] Furthermore, the shortest distance L2a between the first application electrode 5a and the second application electrode 5b in a plan view (see FIG. 6) is preferably greater than the two shortest distances L1a and L1b described above and is 2 to 40 mm. In particular, the shortest distance L2a is more preferably greater than the two shortest distances L1a and L1b described above and is 5 to 15 mm. Furthermore, the shortest distance L2a is more preferably greater than the two shortest distances L1a and L1b described above and is 7 to 15 mm.

[0095] Furthermore, the shortest distance L2b between the first detection electrode 6a and the second detection electrode 6b in a plan view (see FIG. 6) is preferably greater than the two shortest distances L1a and L1b described above and is preferably 2 to 40 mm. In particular, the shortest distance L2b is more preferably greater than the two shortest distances L1a and L1b described above and is more preferably 5 to 15 mm.

[0096] <Control Unit 50> The control unit 50 executes operation instructions and the like for each unit of the wearable device 100. The control unit 50 of this embodiment is configured with a processor such as a CPU or MPU. More specifically, the control unit 50 of this embodiment includes a storage unit such as a ROM (read only memory) or a RAM (random access memory). The storage unit may store, for example, various programs to be executed by the control unit 50. Furthermore, the wearable device 100 may include a storage unit separate from the control unit 50.

[0097] For example, when the control unit 50 detects that the first detection electrode 6 a and the second detection electrode 6 b are in electrical conduction with the surface Z of the user's arm X, the control unit 50 instructs each unit of the wearable device 100 to start measuring bioelectrical impedance. Furthermore, when the control unit 50 detects that the first detection electrode 6 a and the second detection electrode 6 b are in electrical conduction with the surface Z of the user's arm X, the control unit 50 in this embodiment instructs each unit of the wearable device 100, including the detection unit 52 described below, to start measuring a pulse wave.

[0098] Furthermore, the control unit 50 may execute a process of calculating bioelectrical impedance based on the voltage applied between the first application electrode 5a and the second application electrode 5b detected by the first detection electrode 6a and the second detection electrode 6b. Furthermore, the control unit 50 may execute a process of calculating the moisture content from the calculated bioelectrical impedance. The control unit 50 may also transmit the calculated moisture content to an external device such as the user's smartphone, a medical institution's server, or a cloud server via the communication unit 51. However, the control unit 50 may also transmit the measured value of bioelectrical impedance to the external device without executing a process of calculating the moisture content from the calculated bioelectrical impedance. In other words, the process of calculating the moisture content from the bioelectrical impedance calculated by the control unit 50 may be executed by an external device.

[0099] The control unit 50 may execute a process of calculating higher-order biological information such as a heart rate, pulse rate, and blood pressure based on a pulse wave, which is biological information other than the electrical characteristics of a living body, detected by an optical pulse wave sensor serving as the detection unit 52 described below. The control unit 50 may also transmit the calculated higher-order biological information such as a heart rate, pulse rate, and blood pressure to an external device such as a user's smartphone, a medical institution's server, or a cloud server via the communication unit 51. However, the control unit 50 may also transmit the detected biological information itself to the external device without executing a process of calculating higher-order biological information from biological information other than the electrical characteristics of a living body detected by the detection unit 52. In other words, the process of calculating higher-order biological information based on biological information other than the electrical characteristics of a living body detected by the detection unit 52 may be executed by the external device.

[0100] <Communication Unit 51> The communication unit 51 includes at least one of a wireless communication module and a wired communication module. The wireless communication module is a communication module compatible with communication standards such as wireless LAN (local area network), Bluetooth (registered trademark), or NFC (Near Field Communication). The wired communication module may be a wired LAN communication module, for example. This allows the wearable device 100 to communicate wirelessly or wired with a communication terminal such as a smartphone or an external device such as a server via the communication unit 51. The communication unit 51 of this embodiment includes a wireless communication module including an antenna.

[0101] <Detection Unit 52> The detection unit 52 may be a sensor capable of detecting electromagnetic waves or sound waves from a living body. The detection unit 52 of this embodiment is an optical pulse wave sensor that uses photoplethysmography. The wearable device 100 of this embodiment can acquire pulse wave information (pulse wave signal) based on the optical pulse wave sensor serving as the detection unit 52.

[0102] As described above, the detection unit 52 of this embodiment is held by the holder 1. More specifically, the detection unit 52 of this embodiment is housed within the holder 1, and is capable of detecting biological information through the transparent portion serving as the detection window 1c1 described above. The detection unit 52 is electrically connected to the control unit 50 via a conductor. More specifically, the detection unit 52 of this embodiment is fixed to the substrate 3.

[0103] The detection unit 52 of this embodiment includes a light-emitting unit capable of emitting light and a light-receiving unit capable of receiving light. The detection unit 52 can detect pulse wave information by transmitting and receiving optical signals between the light-emitting unit and the light-receiving unit. More specifically, the detection unit 52 of this embodiment includes a first light-emitting unit 52a and a second light-emitting unit 52b capable of emitting light of different wavelengths, and a light-receiving unit 52c capable of receiving light emitted from the first light-emitting unit 52a and the second light-emitting unit 52b and reflected from the living body. In this way, by including the first light-emitting unit 52a and the second light-emitting unit 52b capable of emitting light of different wavelengths in the detection unit 52, erroneous detection of pulse wave information due to, for example, differences in skin color of the living body can be suppressed.

[0104] Furthermore, the first light-emitting unit 52a of this embodiment includes two first light-emitting bodies 52a1 and 52a2. Furthermore, the second light-emitting unit 52b of this embodiment includes two second light-emitting bodies 52b1 and 52b2. In this manner, by each of the first light-emitting unit 52a and the second light-emitting unit 52b including two light-emitting bodies, it is possible to increase the amount of biological tissue through which light passes, and improve detection accuracy, compared to a configuration in which each of the first light-emitting unit 52a and the second light-emitting unit 52b includes only one light-emitting body.

[0105] Furthermore, the two first light emitters 52a1 and 52a2 of the first light emitter 52a are arranged in positions sandwiching the light receiving unit 52c in the longitudinal direction A in a plan view (see FIG. 6). The two second light emitters 52b1 and 52b2 of the second light emitter 52b are arranged in positions sandwiching the light receiving unit 52c in the width direction B in a plan view (see FIG. 6). However, the arrangement of the two first light emitters 52a1 and 52a2 of the first light emitter 52a and the two second light emitters 52b1 and 52b2 of the second light emitter 52b is not limited to the arrangement shown in FIG. 6. The arrangement of the two first light emitters 52a1 and 52a2 of the first light emitter 52a and the two second light emitters 52b1 and 52b2 of the second light emitter 52b may be, for example, the arrangement shown in FIG. 8. Specifically, as shown in Fig. 8, the two first light emitters 52a1 and 52a2 of the first light emitter 52a are arranged in positions sandwiching the light receiving unit 52c in one of the longitudinal direction A and the width direction B (width direction B in Fig. 8) in a plan view (see Fig. 6). The two second light emitters 52b1 and 52b2 of the second light emitter 52b are arranged in positions sandwiching the light receiving unit 52c in the aforementioned one direction (width direction B in Fig. 8) in a plan view (see Fig. 6), and are arranged in a line with the two first light emitters 52a1 and 52a2 along the aforementioned one direction (width direction B in Fig. 8). The two first light emitters 52a1 and 52a2 of the first light emitter 52a and the two second light emitters 52b1 and 52b2 of the second light emitter 52b may be arranged in a line in the longitudinal direction A. In this way, the two first light emitters 52a1, 52a2 of the first light emitter 52a and the two second light emitters 52b1, 52b2 of the second light emitter 52b may be arranged in a row in the longitudinal direction A or the width direction B.

[0106] As shown in FIG. 6 , the detection window 1c1 of the holder 1, in which the detection unit 52 is located, is positioned so as to be surrounded by the four electrodes 4 in a planar view. In other words, the detection unit 52 of this embodiment is positioned so as to be surrounded by the four electrodes 4 in a planar view (see FIG. 6 ). Here, "a position surrounded by the four electrodes 4 in a planar view" does not necessarily mean a position surrounded by all four electrodes 4 in a planar view (see FIG. 6 ), but also means a position between any two of the four electrodes 4. That is, the detection window 1c1 and the detection unit 52 of this embodiment are positioned so as to be between at least any two of the four electrodes 4 in a planar view (see FIG. 6 ). This positioning allows the holder 1 to be miniaturized. The light-receiving unit 52c of this embodiment is positioned so as to be surrounded by all four electrodes 4 in a planar view (see FIG. 6 ).

[0107] <Rechargeable Battery 53 and Charging Terminal 54 > The rechargeable battery 53 of this embodiment is capable of supplying power to each part of the wearable device 100 .

[0108] Charging terminal 54 is electrically connected to rechargeable battery 53. In this embodiment, charging terminal 54 is held by holder 1 so as to be exposed to the outside of holder 1. More specifically, charging terminal 54 in this embodiment is arranged so as to be exposed from inner surface 10 of holder 1. However, charging terminal 54 may also be exposed from a surface of holder 1 other than inner surface 10.

[0109] Next, a modified example of the arrangement of the four electrodes 4 of the present embodiment shown in Fig. 6 will be described with reference to Fig. 9. Fig. 9 is a diagram showing a modified example of the arrangement of the four electrodes 4 of the present embodiment shown in Fig. 6. Fig. 9 is a plan view of the wearable device 100 as seen from the inner surface 10 side of the holder 1. Hereinafter, the plan view shown in Fig. 9 will be simply referred to as "plan view."

[0110] As shown in FIG. 6 , in this embodiment, the relative positional relationship between the first application electrode 5a and the first detection electrode 6a in the width direction B is the same as the relative positional relationship between the second application electrode 5b and the second detection electrode 6b in the width direction B. In contrast, in the modified example shown in FIG. 9 , the relative positional relationship between the first application electrode 5a and the first detection electrode 6a in the width direction B is reversed from the relative positional relationship between the second application electrode 5b and the second detection electrode 6b in the width direction B. That is, the first application electrode 5a shown in FIG. 9 is located on one side (upper side in FIG. 9 ) of the first detection electrode 6a in the width direction B relative to the first detection electrode 6a. In contrast, the second application electrode 5b shown in FIG. 9 is located on the other side (lower side in FIG. 9 ) of the second detection electrode 6b in the width direction B relative to the second detection electrode 6b. More specifically, in the modified example shown in FIG. 9 , the first application electrode 5a is arranged in the first region AE1, and the first detection electrode 6a is arranged in the third region AE3. This is similar to the electrode arrangement shown in FIG. 6 . However, in the modification shown in Fig. 9, the second application electrode 5b is arranged in the fourth area AE4, and the second detection electrode 6b is arranged in the second area AE2, which is different from the electrode arrangement shown in Fig. 6.

[0111] In other words, in a plan view (see FIG. 9), the first application electrode 5a, the second application electrode 5b, the first detection electrode 6a, and the second detection electrode 6b are arranged so that a first line segment LS2, which is the shortest distance L2b between the first detection electrode 6a and the second detection electrode 6b, intersects with a second line segment LS1, which is the shortest distance L2a between the first application electrode 5a and the second application electrode 5b.

[0112] By arranging the four electrodes 4 in this manner, even when the holder 1 is inverted 180 degrees in a plan view (see FIG. 9 ), the positional relationship in the longitudinal direction A and the width direction B between the pair of application electrodes (the first application electrode 5 a and the second application electrode 5 b) and the pair of detection electrodes (the first detection electrode 6 a and the second detection electrode 6 b) does not change. Therefore, there is less likely to be a difference in the measurement results of the biological information between a case where the wearable device 100 is worn on the arm X so that one side in the width direction B (e.g., the upper side in FIG. 9 ) is on the distal side of the arm X and a case where the wearable device 100 is worn on the arm X so that one side in the width direction B (e.g., the upper side in FIG. 9 ) is on the proximal side of the arm X. In other words, the measurement values ​​of the biological information obtained by the wearable device 100 can be more stabilized.

[0113] The wearable device according to the present disclosure is not limited to the specific configurations shown in the above-described embodiments and modifications, and various modifications, alterations, and combinations are possible without departing from the scope of the claims. While the holder 1 in the above-described embodiments and modifications is a member formed from a hard material, as shown in FIG. 10 , the holder 1 may be formed from a soft material that is elastically deformable in the thickness direction C, for example. The holder 1 shown in FIG. 10 is configured to be deformable to follow the circumferential direction E (see FIGS. 4 and 5 ) of the arm X (see FIGS. 4 and 5 ). The holder 1 shown in FIG. 10 is a soft plate-like body, and the substrate 3 and electrodes 4 may be held by the holder 1 by being fixed to the inner surface 10 of the holder 1, for example.

[0114] The present disclosure relates to wearable devices.

[0115] 1: Holder 1a: Internal space 1b: Top wall 1c: Bottom wall 1c1: Detection window 1d: Side wall 1e: Connecting portion 2: Band 3: Substrate 4: Electrode 5a: First application electrode 5a1: Contact surface of first application electrode 5b: Second application electrode 5b1: Contact surface of second application electrode 6a: First detection electrode 6a1: Contact surface of first detection electrode 6b: Second detection electrode 6b1: Contact surface of second detection electrode 10: Inner surface of holder 10a: First outer edge portion of inner surface of holder 10b: Second outer edge portion of inner surface of holder 10c: Third outer edge portion of inner surface of holder 10d: Fourth outer edge portion of inner surface of holder 11: Outer surface of holder 12a, 12b: Two sides along the longitudinal direction 12c, 12d: Two sides along the width direction 13: Corner portion 13a: First corner 13b: Second corner 13c: Third corner 13d: Fourth corner 14: Band receiving member 15: Binding body 20a: First fastening portion of band body 20b: Winding portion of band body 20c: Second fastening portion of band body 20d: Folded-back portion of band body 50: Control unit 51: Communication unit 52: Detection unit 52a: First light-emitting unit 52a1, 52a2: First light-emitting body 52b: Second light-emitting unit 52b1, 52b2: Second light-emitting body 52c: Light-receiving unit 53: Rechargeable battery 54: Charging terminal 100: Wearable device A: Longitudinal direction of wearable device B: Width direction of holder C: Thickness direction of holder E: Circumferential direction of arm F: Thickness direction of band body P1: Midpoint of longitudinal direction of holder P2: midpoint of the holder in the width direction X: arm Y: wrist Z: surface of the arm Z1: back part of the surface of the arm D1: total length of the wearable device in the longitudinal direction D2: length of the electrode arrangement area in the longitudinal direction D3: maximum length of the holder in the longitudinal direction D4: maximum length of the holder in the width direction H: protruding height of the electrode M1: first intermediate line M2: second intermediate line AE: electrode arrangement area AE1: first area of ​​the electrode arrangement area AE2: second area of ​​the electrode arrangement area AE3: third area of ​​the electrode arrangement area AE4: fourth area of ​​the electrode arrangement area L1a: shortest distance between the first application electrode and the first detection electrode L1b: shortest distance between the second application electrode and the second detection electrode L2a: shortest distance between the first application electrode and the second application electrode L2b: shortest distance between the first detection electrode and the second detection electrode LS1: first line segment LS2: second line segment

Claims

1. A wearable device that can be worn on the surface of a living body's arm, comprising: a holder that holds a substrate; a band that is connected to the holder, extends from the holder so as to define the longitudinal direction of the wearable device, and is positioned along the surface of the arm so that the longitudinal direction is circumferential around the arm, thereby being wearable on the arm; and first and second application electrodes that can apply a voltage to the arm and first and second detection electrodes that can detect a voltage or current applied between the first application electrode and the second application electrode, which are held by the holder and exposed on an inner surface of the holder that is positioned opposite the surface of the arm, wherein the holder has an electrode arrangement area that is continuous in the longitudinal direction and in which the first application electrode, the second application electrode, the first detection electrode, and the second detection electrode are arranged, and the electrode arrangement area has a length in the longitudinal direction that is one-third or less of the overall length of the wearable device, and in a plan view of the wearable device seen from the inner surface of the holder, the electrode arrangement region has a first region, a second region, a third region, and a fourth region divided by a first intermediate line of the holder in the longitudinal direction and a second intermediate line in a width direction perpendicular to the longitudinal direction, the first region and the third region being arranged on one side of the first intermediate line in the longitudinal direction, and the first region and the second region being arranged on one side of the second intermediate line in the width direction, the first application electrode, the second application electrode, the first detection electrode, and the second detection electrode being arranged in different regions of the first region, the second region, the third region, and the fourth region, respectively, and the wearable device satisfies the following inequality when the shortest distance between the first application electrode and the first detection electrode is "L1a", the shortest distance between the second application electrode and the second detection electrode is "L1b", the shortest distance between the first application electrode and the second detection electrode is "L2a", and the shortest distance between the first detection electrode and the second detection electrode is "L2b". L2a>L1a, and L2a>L1b, and L2b>L1a, and L2b>L1b 2. The wearable device according to claim 1, wherein, in the plan view, the outer shape of the holder is a substantially rectangular shape having two sides along the longitudinal direction and four corners, and in the plan view, the first application electrode, the second application electrode, the first detection electrode, and the second detection electrode are arranged near different corners of the four corners of the holder.

3. The wearable device of claim 1 or 2, wherein the first application electrode is arranged in the first region, the first detection electrode is arranged in the third region, and the polarity of the first application electrode relative to the second application electrode and the polarity of the first detection electrode relative to the second detection electrode are the same.

4. The wearable device according to claim 3, wherein the distance between the first application electrode and the second application electrode along the longitudinal direction in the plan view is 6 to 40 mm.

5. The wearable device according to claim 3, wherein, in the plan view, the first application electrode and the first detection electrode are arranged so that at least a portion of each electrode overlaps the other electrode in the longitudinal direction.

6. The wearable device according to claim 3, wherein, in the plan view, the second applying electrode and the second detecting electrode are arranged so that at least a portion of each electrode overlaps the other in the longitudinal direction.

7. The wearable device according to claim 3, wherein the first application electrode and the second application electrode are arranged so that, in the plan view, at least a portion of each electrode overlaps the other electrode in the width direction.

8. The wearable device of claim 3, wherein, in the plan view, the first detection electrode and the second detection electrode are arranged so that at least a portion of each electrode overlaps the other electrode in the width direction.

9. The wearable device of claim 1 or 2, wherein, in the planar view, the first application electrode, the second application electrode, the first detection electrode, and the second detection electrode are arranged such that a first line segment forming the shortest distance "L2b" between the first detection electrode and the second detection electrode intersects with a second line segment forming the shortest distance "L2a" between the first application electrode and the second application electrode.

10. The area of ​​the contact surface of each of the first applying electrode, the second applying electrode, the first detecting electrode, and the second detecting electrode facing the surface of the arm is 50 to 200 mm ２ The wearable device according to claim 1 or 2, 11. The wearable device according to claim 1 or 2, wherein the protrusion height of each of the first application electrode, the second application electrode, the first detection electrode, and the second detection electrode from the inner surface of the holder is 0.1 to 5 mm.

12. A wearable device as described in claim 1 or 2, comprising a detection unit held by the holder and capable of detecting biometric information other than electrical characteristics of the living body, the holder having a detection window used for detecting the biometric information by the detection unit, the detection window being positioned in a position surrounded by the first application electrode, the second application electrode, the first detection electrode, and the second detection electrode in the planar view.

13. The wearable device described in claim 12, wherein the detection unit comprises a first light-emitting unit and a second light-emitting unit capable of emitting light of different wavelengths, and a light-receiving unit capable of receiving reflected light emitted from the first light-emitting unit and the second light-emitting unit and reflected from the living body.

14. A wearable device as described in claim 13, wherein the first light-emitting unit comprises two first light-emitting bodies arranged in positions sandwiching the light-receiving unit in the longitudinal direction when viewed in the plane, and the second light-emitting unit comprises two second light-emitting bodies arranged in positions sandwiching the light-receiving unit in the width direction when viewed in the plane.

15. The wearable device described in claim 13, wherein the first light-emitting unit comprises two first light-emitting bodies arranged in positions sandwiching the light-receiving unit in one of the longitudinal direction and the width direction in the planar view, and the second light-emitting unit comprises two second light-emitting bodies arranged in positions sandwiching the light-receiving unit in the one direction in the planar view and arranged in a row with the two first light-emitting bodies along the one direction.

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