Sensor device and pulse rate measuring device

Abstract

To provide a sensor device that can measure pressure fluctuations of the target object with greater accuracy. [Solution] The sensor device according to one embodiment of the present invention comprises a sensor part including a sensor element containing a piezoelectric sheet, and a support part for covering the sensor element, wherein the support part is integrally formed and includes a fixed part to which a part of the sensor part is fixed, a first support part connected to the fixed part, a sensor cover part arranged to cover the sensor element, one end of which is connected to the first support part and is located adjacent to the fixed part, and a second support part connected to the other end of the sensor cover part, wherein the thickness of the first support part and the second support part is greater than the thickness of the sensor cover part and the fixed part.

Description

Technical Field

[0001] The present invention relates to a sensor device and a pulse measurement device.

Background Art

[0002] Conventionally, as a method for measuring weak pressure fluctuations such as the pulse of a living body, there have been methods using an optical sensor, an ultrasonic sensor, a piezoelectric sensor using a polymer piezoelectric film, and the like. Since the polymer piezoelectric film can be made thin and has flexibility, its application to wearable devices such as wristwatches has been considered.

[0003] For example, Patent Document 1 discloses a biosensor that can easily and stably measure a biological vibration even when measuring a biological vibration by applying a curved cover member to cover a strip-shaped piezoelectric sheet against the curved surface of the skin.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The biosensor described in Patent Document 1 is difficult to apply to parts with different degrees of curvature because it uses a curved cover member. In addition, since the piezoelectric sheet and the biosensor are fixed, an unintended force is applied to the piezoelectric sheet when the biosensor is worn, causing the piezoelectric sheet to deform, and there is a risk that weak pressure fluctuations of a measurement target such as the pulse of a human wrist or ankle blood vessel cannot be accurately measured.

[0006] One aspect of the present invention has been made to solve such problems, and an object thereof is to provide a sensor device or the like that can more accurately measure the pressure fluctuation of a measurement target. [Means for solving the problem]

[0007] [1] The sensor device of one embodiment of the present invention is A sensor device for measuring pressure fluctuations of a target object, A sensor unit including a sensor element containing a piezoelectric sheet, A support portion for covering the sensor element, Equipped with, The support portion is formed integrally, A fixing portion to which a part of the sensor unit is fixed, The first support portion connected to the aforementioned fixed portion, A sensor cover portion arranged to cover the aforementioned sensor element, having one end connected to a first support portion and located adjacent to the fixed portion, A second support portion connected to the other end of the aforementioned sensor cover portion, Includes, The thickness of the first support portion and the second support portion is greater than the thickness of the sensor cover portion and the fixing portion. It is a sensor device.

[0008] [2] In one embodiment of the present invention, The sensor portion includes a cover sheet to which the sensor element is fixed, and a portion of the cover sheet is fixed to the fixing portion. The sensor device according to [1], wherein the thickness of the first support portion and the second support portion are substantially the same, and the thickness of the sensor cover portion is greater than the thickness of the fixed portion.

[0009] [3] In one embodiment of the present invention, The sensor cover portion is the sensor device according to [1] or [2], including a first inclined portion connected to the first support portion, a second inclined portion connected to the second support portion, and a bottom portion between the first inclined portion and the second inclined portion.

[0010] [4] In one embodiment of the present invention, The sensor device according to [3], wherein the first inclined portion, the second inclined portion, and the bottom portion are provided on the surface of the sensor cover portion opposite to the surface on which the sensor portion is fixed.

[0011] [5] In one embodiment of the present invention, The sensor device described in [4], wherein the width of the bottom portion of the sensor cover is less than or equal to the width of the sensor portion.

[0012] [6] In one embodiment of the present invention, The sensor device according to [3], wherein the first inclined portion, the second inclined portion, and the bottom portion are provided on the surface of the sensor cover portion to which the sensor portion is fixed.

[0013] [7]In one embodiment of the present invention, The sensor device according to [6], wherein the sum of the widthwise dimensions of the first inclined portion, the second inclined portion, and the bottom portion of the sensor cover is less than or equal to the widthwise dimension of the sensor portion.

[0014] [8] In one embodiment of the present invention, The sensor device according to any one of [1] to [7], wherein the first support portion, the sensor cover portion, and the second support portion have a plurality of recesses on the side opposite to the surface to which the sensor portion is attached.

[0015] [9] In one embodiment of the present invention, The support portion is formed from a soft resin and is a sensor device according to any one of [1] to [8].

[0016]

[10] In one embodiment of the present invention, The sensor device described above is the sensor device described in any one of [1] to [9], which acquires signals resulting from pressure fluctuations in the blood vessels of a human wrist or ankle.

[0017]

[11] A pulse rate measuring device according to one embodiment of the present invention is A pulse measurement device comprising the sensor device according to

[10] , a holding part for holding the sensor device, and a mounting member for mounting so as to surround a human wrist or ankle, wherein the holding part is attached to the mounting member.

Advantages of the Invention

[0018] On one side, according to the present invention, it is possible to measure pressure fluctuations of a measurement object with higher accuracy.

Brief Description of the Drawings

[0019] <00^00100>It is a schematic diagram of a pulse measurement device according to a first embodiment of the present invention. [Figure 2] It is a schematic diagram showing the configuration of a sensor unit according to a first embodiment of the present invention. [Figure 3] It is a diagram showing an example of a cross-sectional view of a sensor element, which is a cross-sectional view cut along a cross-section perpendicular to the surface of the sensor element. [Figure 4] It is a front and planar side perspective view showing the configuration of a support part according to a first embodiment of the present invention. [Figure 5] It is a rear and bottom side perspective view of the support part shown in FIG. 4. [Figure 6] It is a front view of the support part shown in FIG. 4, which is a view seen from the position of A. [Figure 7] It is a rear view of the support part shown in FIG. 4, which is a view seen from the position of B. [Figure 8] It is a rear view of the support part shown in FIG. 4, which is a view seen from the position of B. [Figure 9] It is a rear and bottom side perspective view showing an example of the state when a sensor unit is attached to a support part. [Figure 10] It is a diagram showing an example of the state of the sensor device during wearing. [Figure 11] It is a front and planar side perspective view showing the configuration of a support part according to a second embodiment of the present invention. [Figure 12] It is a rear and bottom side perspective view of the support part shown in FIG. 11. [Figure 13]Figure 11 is a front view of the support section, as seen from position A. [Figure 14] Figure 11 is a rear view of the support section, as seen from position B. [Figure 15] Figure 11 is a rear view of the support section, as seen from position B. [Figure 16] This is a rear and bottom perspective view showing an example of how the sensor unit looks when attached to the support unit. [Figure 17] This figure shows an example of how the sensor device looks when attached. [Modes for carrying out the invention]

[0020] <First Embodiment> Hereinafter, the pulse rate measuring device 1 and sensor device 10 of the first embodiment of the present invention will be described with reference to the drawings. The pulse rate measuring device 1 and sensor device 10 measure pressure fluctuations such as biological vibrations of the object to be measured. In this specification, measuring pressure fluctuations is a concept that includes acquiring signals caused by pressure fluctuations. In this specification, a sheet is a concept that includes a film, and there are no particular restrictions on its thickness; for example, it can represent a thickness of 1 μm to 2 mm. In this specification, curvature is a concept that includes simply bending. In this specification, the same reference numerals in each figure indicate the same or corresponding parts unless otherwise specified, and for the sake of explanation, the vertical and horizontal scales of members or parts may be represented differently from the actual scales. Also, for the sake of explanation, directions such as up, down, left, and right may be used in the description, but unless otherwise specified, the positional relationship is not limited to up, down, left, and right, and the reverse positional relationship is also possible.

[0021] Figure 1 is a schematic diagram of a pulse rate measuring device 1 according to a first embodiment of the present invention. The pulse rate measuring device 1 comprises a sensor device 10, a holding part 2 for holding the sensor device 10, and a mounting member 4 for being attached so as to wrap around the wrist (forearm). The holding part 2 is fixedly attached to the mounting member 4, and the mounting member 4 is configured to be attached so as to wrap around the wrist. For example, the mounting member 4 is a commercially available mounting band. In the description of the first embodiment of the present invention, the object of measurement of the sensor device 10 is assumed to be the blood vessels (pulse) of a human wrist, and the mounting member 4 is assumed to be configured to be attached so as to wrap around the wrist, but the invention is not limited to this.

[0022] The sensor device 10 comprises a sensor unit 20 and a support unit 30. The sensor unit 20 includes a sensor element 21 containing a piezoelectric sheet. The sensor device 10 is configured such that the sensor element 21 is positioned on the surface of the wrist when the attachment member 4 is attached to the wrist, making direct or indirect contact with the wrist, and is capable of sensing pressure fluctuations in the blood vessels of the wrist. In this case, the inner surface of the wrist is the contact surface of the sensor unit 20. For example, the pulse measurement device 1 can acquire data on the pulse of a blood vessel by measuring the pressure fluctuations of that blood vessel.

[0023] In this specification, when describing the state of the sensor device 10, we will describe the case when the pulse measurement device 1 (attachment member 4) is attached to the wrist and the case when the pulse measurement device 1 (attachment member 4) is not attached to the wrist or when the sensor device 10 is not attached to the pulse measurement device 1. In this specification, the former may be referred to as "attached" and the latter as "not attached".

[0024] Figure 2 is a schematic diagram showing the configuration of the sensor unit 20 of the first embodiment of the present invention. The sensor unit 20 includes a sensor element 21, a cover sheet 22, and a fixing member 23. The pulse rate measuring device 1 includes two wires W (not shown) that transmit signals from the sensor element 21, and a signal processing unit 40 that can output pressure fluctuation signals such as biological vibrations caused by the object being measured from the signal acquired from the sensor element 21 via the two wires W. The wires W extend from the sensor element 21 of the sensor unit 20 to the terminals of the signal processing unit 40 via a connection part 41. The wires W on the sensor unit 20 side and the wires W on the signal processing unit side are configured to be separable at the connection part 41. Note that the wires W, signal processing unit 40, and connection part 41 are not essential components of the pulse rate measuring device 1 or sensor unit 20 of this embodiment, as known components can be used. Furthermore, while the portion 20a, which corresponds to the shorter side of the L-shaped sensor portion 20, is connected to the connection portion 41 including the cover sheet 22 and wiring W, the portion of the sensor portion 20 that is related to the main effects of the pulse measurement device 1 and the sensor device 10 of this embodiment is the portion other than portion 20a.

[0025] The sensor element 21 includes a piezoelectric sheet 51 capable of detecting pressure fluctuations, and sheet-like electrodes 52 and 53 attached to both sides of the piezoelectric sheet, respectively. The piezoelectric sheet 51 is formed from or contains a piezoelectric material. In one example, the piezoelectric sheet 51 can be a sheet-like piezoelectric element made from a polymer material. In one example, the piezoelectric sheet 51 can be made of PVDF (PolyVinylidene DiFluoride) or a material containing PVDF. In one example, the electrodes 52 and 53 can be made of a conductive polymer, PEDOT (poly(3,4-ethylenedioxythiophene)):PSS (polystyrene sulfonate) or a material containing PEDOT:PSS.

[0026] Figure 3 shows an example of a cross-sectional view of the sensor element 21, which is a cross-sectional view taken perpendicular to the surface of the sensor element 21. The piezoelectric sheet 51 and electrodes 52, 53 included in the sensor element 21 are produced integrally with the printed substrate on a sheet-like printed substrate by a known method. For example, the printed substrate can be a PEN (Polyethylene Naphthalate) film or a cross-linked PVP, PET (Poly Ethylene Terephthalate), or acrylic formed on a PEN film. After printing, the printed substrate may be used as is, treated as a cover sheet 22, or the printed piezoelectric sheet 51 and electrodes 52, 53 may be peeled from the printed substrate and transferred or attached to the cover sheet 22. Figure 3 shows a cross-sectional view of the sensor element 21 without a printed substrate, but the sensor element 21 may include a printed substrate. In one or more embodiments of the present invention, the sensor element 21 consists of a printed substrate (not shown), a piezoelectric sheet 51 on the printed substrate, and electrodes 52, 53. In the description of embodiments of the present invention, the sensor element 21 is described as consisting of a printed substrate (not shown), a piezoelectric sheet 51 on the printed substrate, and electrodes 52, 53, but is not limited thereto. For example, the total thickness ds of the sensor element 21 is 1 to 30 μm if the printed substrate is not included, in which case, for example, the dimensions (length × width × thickness) of the sensor element 21 are 14 mm × 16 mm × 30 μm. For example, the total thickness of the sensor element 21 is 270 μm if the printed substrate is included, in which case, for example, the dimensions (length × width × thickness) of the sensor element 21 are 14 mm × 16 mm × 270 μm. In these cases, for example, the dimensions (length × width × thickness) of the piezoelectric sheet 51 are 12 mm × 14 mm × 6 μm, and the length × width dimensions of the piezoelectric sheet 51 are slightly smaller than the length × width dimensions of the printing substrate if a printing substrate is included.

[0027] The sensor element 21 is fixed (placed) on the surface of the cover sheet 22. When installed, the sensor element 21 is positioned on the surface of the cover sheet 22 on the side of the support portion 30. The sensor element 21 contacts the surface of the wrist via the cover sheet 22. For example, the sensor element 21 is fixed to the surface of the cover sheet 22 by an adhesive. In this case, a known material can be used as the adhesive, and the adhesive is applied to the necessary locations on the surface of the cover sheet 22, for example, along the edges of the sensor element 21.

[0028] The cover sheet 22 is attached to the support portion 30 via a fixing member 23. In the first embodiment of the present invention, the cover sheet 22 has an opening 24 (not shown), and the cover sheet 22 is attached (fixed) to the support portion 30 through the fixing member 23 in the opening 24. The cover sheet 22 bends or flexes when an external force is applied. In one example, a PET sheet can be used for the cover sheet 22. In one example, a material or substance containing PEN can be used for the cover sheet 22. The cover sheet 22 can transmit pressure fluctuations of the blood vessels (pulse) in the wrist into the cover sheet 22 and transmit those pressure fluctuations to the sensor element 21 that is in contact with the cover sheet 22. Even if the sensor element 21 is not located on the blood vessels in the wrist, the pressure fluctuations of the blood vessels can be transmitted to the sensor element 21 via the cover sheet 22.

[0029] The two electrodes 52 and 53 are each connected to wiring W. Each of the two electrodes 52 and 53 connected to wiring W is then connected to each terminal of the signal processing unit 40. When pressure fluctuations in the blood vessels are transmitted to the piezoelectric sheet 51, the piezoelectric sheet 51 converts the pressure into a corresponding voltage through the piezoelectric effect. This voltage is extracted by electrodes 52 and 53 and output as a voltage signal to the signal processing unit 40 via wiring W. The signal processing unit 40 acquires the voltage signal via electrodes 52 and 53. Since the sensor element 21 converts displacement into voltage, it can sense more efficiently if it is positioned so that it can bend (displace).

[0030] The signal processing unit 40 may include a known amplification circuit for amplifying the acquired voltage signal and a known filtering circuit for extracting a signal of a predetermined frequency from the voltage signal. In one example, the signal processing unit 40 may include a known transmitter for wirelessly transmitting the amplified and filtered signal to an external device. This configuration allows an external device to acquire the voltage signal resulting from pressure fluctuations of the object being measured. In another example, the signal processing unit 40 may include an interface for transmitting the amplified and filtered signal to an external device.

[0031] Furthermore, in order to prevent short circuits between electrodes 52 and 53, the contact area of ​​each contact surface of the piezoelectric sheet 51 with electrodes 52 and 53 is larger than the contact area of ​​each contact surface of electrodes 52 and 53. The size of the surface of the piezoelectric sheet 51 that directly or indirectly contacts the wrist (the contact surface with the wrist) is large enough for the piezoelectric sheet 51 to detect pressure fluctuations. In one example, the size of the contact surface of the piezoelectric sheet 51 with the wrist is, for example, a rectangle with sides of 5 to 50 mm, and particularly preferably a rectangle with sides of 8 to 45 mm, that can detect pressure fluctuations from the arteries (blood vessels) in the wrist.

[0032] Figure 4 is a front and top-side perspective view showing the configuration of the support portion 30 according to the first embodiment of the present invention, and Figure 5 is a rear and bottom-side perspective view of the support portion 30 shown in Figure 4. Figure 4 shows coordinate axes in the x direction (width direction) and y direction (depth direction) which are orthogonal to each other in order to explain the width direction and depth direction of the support portion 30. The coordinate axes shown in Figure 5 correspond to the coordinate axes in Figure 4.

[0033] The support portion (support material) 30 is intended to cover the sensor element 21 so that unintended forces are not applied to the sensor element 21. The support portion 30 is formed as a single unit. In one example, the support portion 30 is formed from a soft resin and manufactured by printing such as a 3D printer or by casting. The support portion 30 includes a fixing portion 31 for fixing a part of the sensor portion 20, a first support portion 32 connected to the fixing portion 31, a sensor cover portion 34 with one end connected to the first support portion 32, and a second support portion 33 connected to the other end of the sensor cover portion 34.

[0034] An opening 36 is formed in the fixing portion 31 for passing the fixing member 23 through. The cover sheet 22 is attached to the fixing portion 31 by aligning the opening 36 and the opening 24 and passing the fixing member 23 through them to fix the cover sheet 22 and the fixing portion 31. In this way, a part of the sensor portion 20 is fixed to the fixing portion 31 of the support portion 30. More specifically, in this case, the sensor portion 20 and the support portion 30 are fixed only in the area on the cover sheet 22 fixed by the fixing member 23 and in the area on the fixing portion 31. For example, fixing using the fixing member 23, the opening 24, and the opening 36 can be done by fixing with eyelets or by crimping.

[0035] The sensor cover portion 34 is not directly connected to the fixing portion 31, but is connected to the fixing portion 31 via the first support portion 32. The sensor cover portion 34 is located adjacent to the fixing portion 31 via a gap 38. When installed, the sensor cover portion 34 is positioned to cover the sensor element 21 which is arranged on one surface of the cover sheet 22.

[0036] Figure 6 is a front view of the support portion 30 shown in Figure 4, as seen from position A. Figures 7 and 8 are rear views of the support portion 30 shown in Figure 4, as seen from position B. In Figures 6 to 8, coordinate axes in the x-direction (width direction) and z-direction (thickness direction), which are orthogonal to each other, are shown to explain the width direction and thickness direction of the support portion 30. The x-axis shown in Figures 6 to 8 corresponds to the x-axis shown in Figure 4. The thickness d1 of the first support portion 32 and the thickness d2 of the second support portion 33 are substantially the same. The thickness d1 (d2) of the first support portion 32 and the second support portion 33 is greater than the thickness d3 of the sensor cover portion 34, and the thickness d3 of the sensor cover portion 34 is greater than the thickness d4 of the fixed portion.

[0037] As shown in Figure 7, the sensor cover portion 34 includes a first inclined portion 34a connected to the first support portion 32, a second inclined portion 34b connected to the second support portion 33, and a bottom portion 34c between the first inclined portion 34a and the second inclined portion 34b. The thickness of the support portion 30 of the first inclined portion 34a slopes smoothly (curvilinearly) in the width direction (x-axis direction) of the support portion 30 from the boundary p2 with the bottom portion 34c to the boundary p1 with the first support portion 32, and changes smoothly (curvilinearly) between p1 and p2, without any points of right-angle change. The thickness of the support portion 30 of the second inclined portion 34b slopes smoothly (curvilinearly) in the width direction of the support portion 30 from the boundary p3 with the bottom portion 34c to the boundary p4 with the second support portion 33, and changes smoothly (curvilinearly) between p3 and p4, without any points of right-angle change.

[0038] For example, as shown in Figure 8, if the thickness d of the support portion 30 is expressed as a function f(x) of the length x in the width direction, it can be said that the entire length from end x0 of the first support portion 32 to end x5 of the second support portion 33 is a differentiable continuous straight line or curve. For example, f(x) is a constant value from x0 to x1 and from x4 to x5. For example, f(x) is differentiable at x1, x2, x3, and x4, and forms a smooth curve at these points. However, the above example illustrates how the thickness d of the support portion 30 changes smoothly with respect to the width direction, and does not require strict differentiability.

[0039] The sum of the widths (length in the x-axis direction) of the first inclined portion 34a and the second inclined portion 34b (wa + wb) is 20-55% of the width (wa + wb + wc) of the sensor cover portion 34.

[0040] The first support portion 32, the sensor cover portion 34, and the second support portion 33 each have a plurality of recesses 37 on the side of the support portion 30 opposite to the side to which the sensor portion 20 is attached, while the side of the support portion 30 to which the sensor portion 20 is attached is flat and does not have any recesses.

[0041] Figure 9 is a rear and bottom perspective view showing an example of how the sensor unit 20 is attached to the support unit 30. From Figure 9, it can be seen that the cover sheet 22 is attached to the support unit 30 via the fixing member 23. The sensor element 21 is covered by the sensor cover unit 34, not the fixing unit 31. The width (x-axis direction) wc of the support unit 30 at the bottom 34c of the sensor cover unit 34 is less than or equal to the width (x-axis direction) ws of the cover sheet 22 (sensor unit 20) covered by the sensor cover unit 34. For the sake of explanation, the depiction of wiring and connection parts 41, etc., has been omitted.

[0042] Figure 10 shows an example of the sensor device 10 when attached. When the support portion 30 bends along the width direction (x-axis direction) during attachment, the sensor cover portion 34 bends, and the first support portion 32 and the second support portion 33 contact the wrist 60 in areas R1 and R2, respectively, and the support portion 30 becomes stable. At this time, in the width direction (x-axis direction), the length of the cover sheet 22 covering the sensor cover portion 34 is longer than the bottom portion 34c. Therefore, even if the sensor cover portion 34 bends so that the central part moves away from the wrist 60, the cover sheet 22 is configured to be pressed in two areas R3 and R4, and can stay close to the wrist 60 without floating away, and a space S is formed between the sensor portion 20 and the support portion 30. The cover sheet 22 covering the sensor cover portion 34 is held in an undeformed state as no force is applied to areas other than the two areas that are pressed. Therefore, the sensor element 21 can be held in an undeformed state without being subjected to external stimuli, and the presence of space S allows the sensor element 21 to more efficiently sense pressure fluctuations in the blood vessels of the wrist 60, enabling more accurate measurement of minute pressure fluctuations in the target of measurement.

[0043] Next, the operation and effects of the sensor device 10 (pulse rate measuring device 1) according to the first embodiment of the present invention will be described.

[0044] In a first embodiment of the present invention, the sensor device 10 comprises a sensor unit 20 and a support unit 30. The sensor unit 20 includes a sensor element 21, a cover sheet 22, and a fixing member 23. The support unit 30 is integrally formed and includes a fixing unit 31 to which a portion of the cover sheet 22 is fixed, a first support unit 32, a sensor cover unit 34, and a second support unit 33. The sensor element 21 is arranged on one surface of the cover sheet 22 and is positioned to be covered by the sensor cover unit 34. The thickness d3 of the sensor cover unit 34 is smaller than the thickness d1 (d2) of the first support unit 32 and the second support unit 33, making the sensor cover unit 34 easily bendable.

[0045] With this configuration, when the sensor device 10 bends along its longitudinal direction (the width direction of the support portion 30) during attachment, the sensor cover portion 34 bends, and the first support portion 32 and the second support portion 33 follow suit and are pressed against the wrist 60, resulting in a stable support portion 30. At this time, in the width direction of the support portion 30, the length wc of the bottom portion 34c is less than or equal to the length ws of the cover sheet 22 covered by the sensor cover portion 34. As a result, the cover sheet 22 is pressed in two regions R3 and R4, and a space S is formed between the sensor portion 20 and the support portion 30. The cover sheet 22 covered by the sensor cover portion 34 is not subjected to force in areas other than the two pressed regions and is held in an undeformed state, thus allowing the sensor element 21 to be held in an undeformed state. Furthermore, in this embodiment, by fixing the cover sheet 22 to the fixing portion 31 and fixing the sensor portion 20 (a part of the sensor portion 20) to the support portion 30 (a part of the support portion 30), it is possible to reduce the influence of vibration and deformation of the support portion 30 on the sensor element 21.

[0046] In this way, since the sensor element 21 is protected by the support part 30 when worn, it is possible to reduce external noise when accurately measuring weak pressure fluctuations, and thus it becomes possible to measure the weak pressure fluctuations of the target object with greater accuracy. In addition, since a space S is formed when worn, and space is secured for the sensor element 21 to be displaced, the sensor element 21 can more efficiently sense the pressure fluctuations of the blood vessels in the wrist 60.

[0047] Furthermore, in this embodiment, the thickness of the fixed portion 31 is smaller than the thickness of the sensor cover portion 34, and when the sensor device 10 is curved along its longitudinal direction, the fixed portion 31 is configured to bend less than the curve of the sensor cover portion 34. In this way, by forming the fixed portion 31 as thin as possible so that it is easier to bend or can be deformed more freely, it is possible to further reduce the impact on the cover sheet 22 to which the sensor element 21 is attached.

[0048] Furthermore, in this embodiment, the thickness of the support portion 30 changes smoothly in the width direction, across the first support portion 32, the sensor cover portion 34, and the second support portion 33, and does not have any points where it changes at a right angle. This reduces the load on the support portion 30 when it bends during installation, thereby preventing damage.

[0049] In this embodiment, the first support portion 32, the sensor cover portion 34, and the second support portion 33 each have a plurality of recesses 37 on the side of the support portion 30 opposite to the side to which the sensor portion 20 is attached. This configuration makes it possible to prevent deterioration such as cracking of the resin portion when bending motion is repeated. In addition, because it does not penetrate to the back surface, the amount of deformation of the resin portion is suppressed, allowing for appropriate bending and support. Furthermore, it is possible to reduce the weight of the sensor support material and the amount of material used.

[0050] Furthermore, in this embodiment, the support portion 30 is formed as a single unit. Because it is a single unit, it does not have a complex structure, and problems caused by joints (such as poor connection, damage, or peeling) can be avoided, making it easy to reduce weight.

[0051] <Second Embodiment> Hereinafter, with reference to the drawings, a pulse rate measuring device 1 and a sensor device 10 according to a second embodiment of the present invention will be described.

[0052] Figure 11 is a front and top-side perspective view showing the configuration of the support portion 30α of the sensor device 10 in the pulse measurement device 1 of the second embodiment of the present invention, and Figure 12 is a rear and bottom-side perspective view of the support portion 30α shown in Figure 11. In Figure 11, coordinate axes in the x direction (width direction) and y direction (depth direction), which are orthogonal to each other, are shown to explain the width direction and depth direction of the support portion 30α. The coordinate axes shown in Figure 12 correspond to the coordinate axes in Figure 11.

[0053] The support portion (support material) 30α is intended to cover the sensor element 21 so that unintended forces are not applied to the sensor element 21. The support portion 30α is formed as a single unit. In one example, the support portion 30α is formed from a soft resin and manufactured by printing such as a 3D printer or by casting. The support portion 30α includes a fixing portion 31α for fixing a part of the sensor portion 20, a first support portion 32α connected to the fixing portion 31α, a sensor cover portion 34α with one end connected to the first support portion 32α, and a second support portion 33α connected to the other end of the sensor cover portion 34α.

[0054] An opening 36 is formed in the fixing portion 31α for passing the fixing member 23 through. The cover sheet 22 is attached to the fixing portion 31α by aligning the opening 36 and the opening 24 and passing the fixing member 23 through it to fix the cover sheet 22 and the fixing portion 31α. In this way, a part of the sensor portion 20 is fixed at the fixing portion 31α of the support portion 30. More specifically, in this case, the sensor portion 20 and the support portion 30α are fixed only in the area on the cover sheet 22 fixed by the fixing member 23 and in the area on the fixing portion 31α. For example, fixing using the fixing member 23, the opening 24, and the opening 36 can be done by fixing with eyelets or by crimping.

[0055] The sensor cover portion 34α is not directly connected to the fixing portion 31α, but is connected to the fixing portion 31α via the first support portion 32α. The sensor cover portion 34α is located adjacent to the fixing portion 31α via a gap 38. When installed, the sensor cover portion 34α is positioned to cover the sensor element 21 which is arranged on one surface of the cover sheet 22.

[0056] Figure 13 is a front view of the support portion 30α shown in Figure 11, as seen from position A. Figures 14 and 15 are rear views of the support portion 30α shown in Figure 11, as seen from position B. In Figures 13 to 15, coordinate axes in the x-direction (width direction) and z-direction (thickness direction), which are orthogonal to each other, are shown to explain the width direction and thickness direction of the support portion 30α. The x-axis shown in Figures 13 to 15 corresponds to the x-axis shown in Figure 11. The thickness d1α of the first support portion 32α and the thickness d2α of the second support portion 33α are substantially the same. The thickness d1α (d2α) of the first support portion 32α and the second support portion 33α is greater than the thickness d3α of the sensor cover portion 34α, and the thickness d3α of the sensor cover portion 34α is greater than the thickness d4α of the fixed portion 31α.

[0057] As shown in Figure 14, the sensor cover portion 34α includes a first inclined portion 34aα connected to the first support portion 32α, a second inclined portion 34bα connected to the second support portion 33α, and a bottom portion 34cα between the first inclined portion 34aα and the second inclined portion 34bα. The first inclined portion 34aα, the second inclined portion 34bα, and the bottom portion 34cα are provided on the surface of the sensor cover portion 34α to which the sensor portion 20 is fixed. The first inclined portion 34aα is linearly inclined in the width direction (x-axis direction) of the support portion 30α from the boundary p2α with the bottom portion 34cα to the boundary p1α with the first support portion 32α, and bends at an obtuse angle between p1α and p2α. The second inclined portion 34bα is linearly inclined in the width direction of the support portion 30α from the boundary p3α with the bottom portion 34cα to the boundary p4α with the second support portion 33α, and is bent at an obtuse angle between p3α and p4α.

[0058] For example, as shown in Figure 15, if the thickness dα of the support portion 30α is expressed as a function of the length x in the width direction, fα(x), then it can be said that the entire length from the end x0α of the first support portion 32α to the end x5α of the second support portion 33 is a differentiable continuous straight line or curve. For example, fα(x) is a constant value from x0α to x1α and from x4α to x5α. For example, f(x) is differentiable at x1α, x2α, x3α, and x4α, and the shape is bent at obtuse angles at these points. However, the above example illustrates how the thickness d of the support portion 30α changes smoothly with respect to the width direction, and it is not required that it be strictly differentiable.

[0059] The sum of the widths (length in the x-axis direction) of the first inclined portion 34aα and the second inclined portion 34bα (waα + wbα) is 20-55% of the width (waα + wbα + wcα) of the sensor cover portion 34α.

[0060] The first support portion 32α, the sensor cover portion 34α, and the second support portion 33α each have a plurality of recesses 37 on the side of the support portion 30α opposite to the side to which the sensor portion 20 is attached, while the side of the support portion 30α to which the sensor portion 20 is attached is flat and does not have any recesses.

[0061] Figure 16 is a rear and bottom perspective view showing an example of how the sensor unit 20 is attached to the support unit 30α. From Figure 16, it can be seen that the cover sheet 22 is attached to the support unit 30α via the fixing member 23. The sensor element 21 is covered by the sensor cover unit 34α, not by the fixing unit 31α. The width (x-axis direction) of the sensor cover unit 34α (waα + wbα + wcα) is less than or equal to the width (x-axis direction) of the cover sheet 22 (sensor unit 20) covered by the sensor cover unit 34 (ws). For the sake of clarity, wiring and connection parts 41 have been omitted from the drawing.

[0062] Figure 17 shows an example of the sensor device 10 when attached. When the support portion 30α bends along the width direction (x-axis direction) during attachment, the sensor cover portion 34α bends, and the first support portion 32α and the second support portion 33α are in contact with the wrist 60 in areas R1α and R2α, respectively, and the support portion 30α becomes stable. The sensor portion 20 also becomes stable when the cover sheet 22 is in contact with the first support portion 32α and the second support portion 33α in areas R3α and R4α, respectively. At this time, in the width direction (x-axis direction), the length of the cover sheet 22 covering the sensor cover portion 34α is longer than the length of the sensor cover portion 34α (waα + wbα + wcα), and is longer than the width of the opening between the connection between the first inclined portion 34aα and the first support portion 32α and the connection between the second inclined portion 34bα of the sensor cover portion 34α and the second support portion 33α. Therefore, even if the sensor cover portion 34α bends so that its central portion moves away from the wrist 60, the cover sheet 22 is configured to be pressed by two regions R3α and R4α. As a result, it can stay close to the wrist 60 without floating away from it, and a space Sα is formed between the sensor portion 20 and the support portion 30α. The cover sheet 22, which covers the sensor cover portion 34α, is held in an undeformed state as no force is applied to areas other than the two areas that are pressed. Therefore, the sensor element 21 can be held in an undeformed state without being subjected to external stimuli, and the presence of space Sα allows the sensor element 21 to more efficiently sense pressure fluctuations in the blood vessels of the wrist 60, enabling more accurate measurement of minute pressure fluctuations in the target object. Furthermore, since the first inclined portion 34aα, the second inclined portion 34bα, and the bottom portion 34cα are provided on the surface of the sensor cover portion 34α to which the sensor portion 20 is fixed, space Sα is secured even when the surface is not curved. Therefore, even if the degree of curvature of the wrist 60 differs from person to person, pressure fluctuations in the blood vessels can be sensed more efficiently, enabling more accurate measurement of minute pressure fluctuations in the target object.

[0063] The effects described above are the same in other embodiments and other examples unless otherwise specified.

[0064] In embodiments of the present invention, the first inclined portion, the second inclined portion, and the bottom portion can be provided on both the surface of the sensor cover portion to which the sensor portion is fixed, and the surface of the sensor cover portion opposite to the surface to which the sensor portion is fixed.

[0065] In embodiments of the present invention, the sensor element 21 is not limited to consisting of a printed substrate, a piezoelectric sheet 51 on the printed substrate, and electrodes 52 and 53, as long as the sensor device 10 achieves at least one of the effects described above. For example, the sensor element 21 may not include a printed substrate, or it may include other components. If the sensor element 21 does not include a printed substrate, for example, the dimensions (length × width × thickness) of the sensor element 21 can be 14 mm × 16 mm × 20 μm. For example, the sensor element 21 may have an insulating layer provided on top of the electrode 52. In this case, the sensor element 21 may comprise a piezoelectric sheet 51, electrodes 52 and 53, and an insulating layer.

[0066] In embodiments of the present invention, the sensor element 21 may include a piezoelectric sheet 51 and any configuration capable of acquiring pressure fluctuations (voltage signals) detected in the piezoelectric sheet 51, provided that the sensor device 10 achieves at least one of the effects described above. Alternatively, in one or more embodiments of the present invention, the sensor element 21 may equal the piezoelectric sheet 51. In this case, the sensor device 10 may include a configuration capable of acquiring voltage signals detected in the piezoelectric sheet 51 and may have a function for measuring pressure fluctuations.

[0067] In embodiments of the present invention, the dimensions of the sensor element 21 and its position on the cover sheet 22 can differ from those described in the above embodiments of the present invention, as long as the configuration allows for holding the sensor element 21 in a manner that prevents deformation during installation. Similarly, in embodiments of the present invention, the position and method of fixing the sensor element 21 to the cover sheet 22 are not limited to those described in the above embodiments of the present invention.

[0068] In embodiments of the present invention, fixing the sensor element 21 to the cover sheet 22 includes not only direct fixing of the sensor element 21 to the cover sheet 22, but also indirect fixing. The same applies to fixing other components. In one or more embodiments of the present invention, the sensor element 21 may be fixed to the surface of the cover sheet 22 by adhesive tape or other adhesive material or substance other than adhesive, or it may be fixed to the cover sheet 22 by engaging or fitting the sensor element 21 to a structure provided on the cover sheet 22. For example, when fixing to the cover sheet 22 with adhesive tape, the sensor element 21 can be fixed to the cover sheet 22 by applying adhesive tape to the entire outer edge or to two opposing edge portions. For example, when using adhesive tape, insulating polyimide adhesive tape can be used.

[0069] In embodiments of the present invention, the cover sheet 22 does not need to be attached via the fixing member 23, as long as it is attached to the support portion 30 at the fixing portion 31. For example, in this case, no opening 24 is formed in the cover sheet 22, no opening 36 is formed in the fixing portion 31, and the cover sheet 22 may be fixed at the fixing portion 31 by an adhesive material such as an adhesive, or it may be fixed by engaging or fitting the cover sheet 22 with a structure provided on the fixing portion 31.

[0070] In embodiments of the present invention, the support portion 30 does not need to have any recesses 37 formed therein. In embodiments of the present invention, the support portion 30 may be a hole through which the bottom of a recess 37 has been penetrated, rather than a recess 37.

[0071] In embodiments of the present invention, the support portion 30 may have portions that change perpendicularly in the width direction.

[0072] In the embodiment of the present invention, the thickness d1 of the first support portion and the thickness d2 of the second support portion do not have to be the same as long as they are greater than the thickness d3 of the sensor cover portion 34 and the thickness d4 of the fixing portion 31, and the thickness d4 of the fixing portion 31 does not have to be less than the thickness d3 of the sensor cover portion 34, as long as the configuration is such that the sensor element 21 can be held in place so as not to deform when attached.

[0073] In embodiments of the present invention, the size wc in the width direction (x-axis direction) of the support portion 30 at the bottom 34c of the sensor cover portion 34 may be larger than the size ws in the width direction (x-axis direction) of the cover sheet 22 (sensor portion 20) covered by the sensor cover portion 34, as long as the configuration allows for holding the sensor element 21 so as not to deform when attached.

[0074] In embodiments of the present invention, the sensor element 21 can also be configured to be positioned on the surface of the cover sheet 22 opposite to the support portion 30 so as to directly contact the surface of the wrist when worn.

[0075] In one or more embodiments of the present invention, the measurement target of the sensor device 10 can be the blood vessels (pulse) of a human ankle instead of blood vessels (pulse), or blood vessels of other parts of the body. In other words, the pulse measurement device 1 is not limited to the embodiment shown in Figure 1, and it is sufficient that the sensor device 10 can measure pressure fluctuations of a measurement target such as blood vessels (pulse) of the wrist or ankle. In one or more embodiments of the present invention, the measurement target of the sensor device 10 can be something other than human blood vessels or a living organism that generates pressure fluctuations of a magnitude similar to a pulse. For example, the sensor device 10 may be the sensor device 10 of a device other than the pulse measurement device 1 used for measuring pressure fluctuations other than pulse. The sensor device 10 may be configured to be used on its own.

[0076] The embodiments described above are illustrative examples for illustrating the present invention, and the present invention is not limited to these embodiments. The embodiments can be combined as appropriate and applied to any embodiment of the present invention, provided that no contradictions arise. In other words, the present invention can be implemented in various forms without departing from its essence. [Explanation of Symbols]

[0077] 1: Pulse rate measuring device 2: Holding part 4: Mounting component 10: Sensor device 20: Sensor section 21: Sensor element 22: Cover sheet 23: Fixing member 24:Aperture 30: Support part 31:Fixed part 32: First support part 33: Second support part 34: Sensor cover part 36:Aperture 37: Recess 38: Gap 40: Signal Processing Unit 41: Connection part 51: Piezoelectric sheet 52: Electrode 53: Electrode 60: Wrist

Claims

1. A sensor device for measuring pressure fluctuations of a target object, A sensor unit including a sensor element containing a piezoelectric sheet, A support portion for covering the sensor element, Equipped with, The support portion is formed integrally, A fixing portion to which a part of the sensor unit is fixed, The first support portion connected to the aforementioned fixed portion, A sensor cover portion arranged to cover the aforementioned sensor element, having one end connected to a first support portion and positioned adjacent to the fixed portion, A second support portion connected to the other end of the sensor cover portion, Includes, The thickness of the first support portion and the second support portion is greater than the thickness of the sensor cover portion and the fixing portion. Sensor device.

2. The sensor portion includes a cover sheet to which the sensor element is fixed, and a portion of the cover sheet is fixed to the fixing portion. The sensor device according to claim 1, wherein the thickness of the first support portion and the second support portion are substantially the same, and the thickness of the sensor cover portion is greater than the thickness of the fixed portion.

3. The sensor device according to claim 1, wherein the sensor cover portion includes a first inclined portion connected to the first support portion, a second inclined portion connected to the second support portion, and a bottom portion between the first inclined portion and the second inclined portion.

4. The sensor device according to claim 3, wherein the first inclined portion, the second inclined portion, and the bottom portion are provided on the surface of the sensor cover portion opposite to the surface on which the sensor portion is fixed.

5. The sensor device according to claim 4, wherein the width of the bottom portion of the sensor cover is less than or equal to the width of the sensor portion.

6. The sensor device according to claim 3, wherein the first inclined portion, the second inclined portion, and the bottom portion are provided on the surface of the sensor cover portion to which the sensor portion is fixed.

7. The sensor device according to claim 6, wherein the sum of the widthwise dimensions of the first inclined portion, the second inclined portion, and the bottom portion of the sensor cover is less than or equal to the widthwise dimension of the sensor portion.

8. The sensor device according to claim 1, wherein the first support portion, the sensor cover portion, and the second support portion each have a plurality of recesses on the side opposite to the surface to which the sensor portion is attached.

9. The sensor device according to claim 1, wherein the support portion is formed from a soft resin.

10. The sensor device according to any one of claims 1 to 9, wherein the sensor device acquires signals resulting from pressure fluctuations in the blood vessels of a human wrist or ankle.

11. A pulse rate measuring device, A pulse rate measuring device comprising a sensor device according to claim 10, a holding part for holding the sensor device, and a mounting member for attaching to a person's wrist or ankle, wherein the holding part is attached to the mounting member.

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