Pressing device and blood pressure measuring device

Abstract

This pressing device is for pressing a pressure sensor against a radial artery, said pressure sensor being for measuring chronological variation in blood pressure. The pressing device has a first surface where the pressure sensor is positioned. When the pressure sensor is pressed against the radial artery, the first surface faces the radius with the radial artery interposed therebetween.

Description

Pressing device and blood pressure measuring device

[0001] The technology disclosed in this specification relates to a pressing device for pressing a pressure sensor for measuring the change in blood pressure over time against the radial artery.

[0002] A wristwatch-type blood pressure measuring device that is worn on a person's wrist to measure blood pressure values has been proposed (see, for example, Patent Document 1). This blood pressure measuring device includes, for example, a pressure sensor using a piezoelectric element.

[0003] Japanese Patent Application Laid-Open No. 2024-002183

[0004] Conventional blood pressure measuring devices include a cuff (armband) for compressing an artery. Therefore, due to the presence of the cuff, the device tends to be relatively large. Also, due to the compression of the artery by the cuff, it is easy for the user to feel a sense of compression and a burden on the heart. Thus, conventional blood pressure measuring devices have the problem of requiring a cuff in order to accurately measure blood pressure.

[0005] This specification discloses a technology that can solve the above-described problems.

[0006] The technology disclosed in this specification can be realized, for example, in the following forms.

[0007] (1) The pressing device disclosed in this specification is for pressing a pressure sensor for measuring the change in blood pressure over time against the radial artery. The pressing device has a first surface on which the pressure sensor is disposed. When the pressure sensor is pressed against the radial artery, the first surface faces the radius across the radial artery. According to this pressing device, since the first surface presses the pressure sensor toward the radial artery, the change in blood pressure over time can be accurately measured by the pressure sensor without using a cuff.

[0008] (2) The pressing device may further have a second surface inclined with respect to the first surface, and when the pressure sensor is pressed against the radial artery, the second surface may be positioned to be aligned with the first surface in the circumferential direction of the radius and to cover at least a portion of the styloid process of the radius. With this configuration, the position of the pressure sensor can be easily determined, and changes in blood pressure over time can be accurately measured by the pressure sensor without using a cuff.

[0009] (3) In the pressing device described above, the second surface may be a curved surface that bends along the circumferential direction of the radius. With this configuration, the position of the pressure sensor can be more easily determined because the second surface conforms to the shape of the human wrist, so that changes in blood pressure over time can be measured more accurately by the pressure sensor without using a cuff.

[0010] (4) In the pressing device described above, a recess is formed on the second surface, and the recess may cover at least a portion of the styloid process of the radius. With this configuration, the position of the pressure sensor can be more easily determined by the engagement of the recess with the styloid process of the radius, so that changes in blood pressure over time can be measured with greater accuracy by the pressure sensor without using a cuff.

[0011] (5) In the pressing device described above, the first surface and the second surface may be joined to each other. With this configuration, the first surface and the second surface are shaped to conform to the surface of a person's wrist, making it easier to determine the position of the pressure sensor, and thus enabling more accurate measurement of changes in blood pressure over time by the pressure sensor without using a cuff.

[0012] (6) The pressing device may further have a third surface located on the opposite side of the second surface from the first surface and inclined with respect to the first surface, and a space may be formed enclosed by the first surface, the second surface and the third surface. With this configuration, the position of the pressure sensor can be more easily determined by accommodating the person's wrist in the space, so that changes in blood pressure over time can be measured with greater accuracy by the pressure sensor without using a cuff.

[0013] (7) In the pressing device described above, the first distance, which is the distance between the end of the second surface located on the opposite side of the first surface and the end of the third surface located on the opposite side of the first surface, may be equal to the distance from the end of the styloid process of the radius to the end of the styloid process of the ulna of the target user. With this configuration, the space is shaped to better fit the surface of the human wrist, making it easier to determine the position of the pressure sensor, and thus enabling more accurate measurement of changes in blood pressure over time by the pressure sensor without using a cuff.

[0014] (8) In the pressing device described above, the second distance, which is the distance between the end on the second surface that is on the same side as the first surface and the end on the second surface that is on the opposite side of the first surface, in the direction connecting the end on the second surface that is on the opposite side of the first surface and the end on the third surface that is on the opposite side of the first surface, may be one-tenth or more and one-fifth or less of the first distance. With this configuration, the space is shaped to better fit the surface of a person's wrist, making it easier to determine the position of the pressure sensor, and thus enabling more accurate measurement of changes in blood pressure over time by the pressure sensor without using a cuff.

[0015] (9) In the pressing device described above, the third distance, which is the shortest distance between the imaginary straight line connecting the end of the second surface located on the opposite side of the first surface and the end of the third surface located on the opposite side of the first surface and the first surface, may be one-quarter or more and one-third or less of the thickness of the user's wrist. With this configuration, the space takes on a shape that better matches the surface of a person's wrist, making it easier to determine the position of the pressure sensor, and thus enabling more accurate measurement of changes in blood pressure over time by the pressure sensor without using a cuff.

[0016] (10) In the pressing device described above, the second surface is a curved surface that curves in an arc along the circumferential direction of the radius, and the radius of the virtual arc along the shape of the second surface may be the same as or greater than the third distance. With this configuration, the space is shaped to better fit the surface of the human wrist, making it easier to determine the position of the pressure sensor, and thus enabling more accurate measurement of changes in blood pressure over time by the pressure sensor without using a cuff.

[0017] (11) The blood pressure measuring device disclosed herein comprises the pressing device and the pressure sensor disposed on the first surface. With this blood pressure measuring device, the position of the pressure sensor can be easily determined, so that changes in blood pressure over time can be accurately measured by the pressure sensor without using a cuff.

[0018] (12) The blood pressure measuring device may further include a pressure sensor pad located between the first surface and the pressure sensor, which is made of a porous material with an elastic modulus of 0.1 MPa or less, and the thickness of the pressure sensor pad is 3 mm or more and 10 mm or less. With this configuration, the position of the pressure sensor can be easily determined, so that changes in blood pressure over time can be measured accurately by the pressure sensor without using a cuff.

[0019] (13) In the blood pressure measuring device described above, the pressure sensor may include a piezoelectric element. With this configuration, changes in blood pressure over time can be measured with the same accuracy as when a capacitive pressure sensor is used.

[0020] Furthermore, the technologies disclosed herein can be realized in various forms, for example, as a pressing device, a blood pressure measuring device equipped with a pressure sensor and a pressing device, a method for manufacturing a blood pressure measuring device, and a method for using a blood pressure measuring device.

[0021] Diagram illustrating the configuration of a blood pressure measuring device Diagram illustrating the configuration of a blood pressure measuring device Diagram illustrating the state of wearing the blood pressure measuring device Diagram illustrating an example of the change in blood pressure values ​​measured by the blood pressure measuring device over time Perspective view of the main body of the first embodiment showing the side not facing the person's wrist Perspective view of the main body of the first embodiment showing the side facing the person's wrist Front view of the main body of the first embodiment Rear view of the main body of the first embodiment Left side view of the main body of the first embodiment Right side view of the main body of the first embodiment Top view of the main body of the first embodiment Bottom view of the main body of the first embodiment Perspective view of the main body of the second embodiment showing the side facing the person's wrist Right side view of the main body of the second embodiment Bottom view of the main body of the second embodiment Third embodiment A perspective view of the main body of the third embodiment showing the side facing a person's wrist Left side view of the main body of the third embodiment Right side view of the main body of the third embodiment Bottom view of the main body of the third embodiment A perspective view of the main body of the fourth embodiment showing the side facing a person's wrist Left side view of the main body of the fourth embodiment Right side view of the main body of the fourth embodiment Bottom view of the main body of the fourth embodiment A perspective view of the main body of the fifth embodiment showing the side not facing a person's wrist A perspective view of the main body of the fifth embodiment showing the side facing a person's wrist Front view of the main body of the fifth embodiment Rear view of the main body of the fifth embodiment Left side view of the main body of the fifth embodiment Right side view of the main body of the fifth embodiment Top view of the main body of the fifth embodiment Bottom view of the main body of the fifth embodiment

[0022] (First Embodiment) Figures 1 and 2 are explanatory diagrams showing the configuration of the blood pressure measuring device 100. In Figure 2, the band 40, which will be described later, is omitted from the blood pressure measuring device 100. Figure 3 is an explanatory diagram showing the state in which the blood pressure measuring device 100 is worn.

[0023] The blood pressure measuring device 100 is a device for measuring a person's blood pressure. As shown in Figure 3, the blood pressure measuring device 100 is attached to a person's wrist WP and measures the blood pressure value for each heartbeat using a pressure sensor 20 that is pressed against the radial artery BV running on the radius RA near the body surface SU, according to the tonometry method. In this specification, the part of a person's wrist WP that is on the same side as the person's palm is sometimes referred to as the "medial side," and the part of a person's wrist WP that is on the same side as the person's back of the hand is sometimes referred to as the "lateral side."

[0024] The blood pressure measuring device 100 includes a band 40, a main body 30, a display 50, a pressure sensor 20, and a pressure sensor pad (hereinafter also simply referred to as "pad") 10.

[0025] The band 40 is a belt-shaped component for securing the blood pressure measuring device 100 to a person's wrist WP. The main body 30 is attached to the band 40.

[0026] The main unit 30 is the part that controls the entire blood pressure measuring device 100. When the blood pressure measuring device 100 is attached to a person's wrist WP, the main unit 30 is located on the inside of the person's wrist WP. The main unit 30 includes, for example, an integrated circuit, a communication interface, and a battery that supplies power to each part. The main unit 30 communicates with the pressure sensor 20 and other devices via the communication interface, for example, in accordance with a communication standard such as Bluetooth®. As will be described in detail later, the main unit 30 also functions as a device for pressing the pressure sensor 20 against the radial artery BV. Due to the presence of the main unit 30, the blood pressure measuring device 100 can measure blood pressure and other biological information with high accuracy without using a cuff. The main unit 30 is an example of a pressing device.

[0027] The display 50 is a display device that shows various images such as measurements taken by the blood pressure measuring device 100. The display 50 is attached to the main unit 30. In the example in Figure 1, the display 50 shows a graph showing the change in blood pressure values ​​over time, the systolic blood pressure value (117), the diastolic blood pressure value (71), etc.

[0028] The pressure sensor 20 is a sensor for measuring changes in pressure over time. The pressure sensor 20 is located on the first surface 31 of the main body 30, which will be described later. The pressure sensor 20 is equipped with a piezoelectric element that outputs an electrical signal corresponding to the force (pressure). In this embodiment, a pressure sensor 20 is used in which a PZT (lead zirconate titanate) film as a piezoelectric element is deposited on a flexible substrate.

[0029] The pad 10 is located between the main body 30 and the pressure sensor 20. The pad 10 is a component for pressing the pressure sensor 20 against a person's wrist WP. In this embodiment, the pad 10 is a porous material, for example, made of a foamed superelastic material. Specifically, the pad 10 is made of a porous material with an elastic modulus of 0.1 MPa or less. The elastic modulus of the material forming the pad 10 may be 0.08 MPa or less, 0.05 MPa or less, or 0.01 MPa or less. Examples of materials for forming the pad 10 include polyurethane sponge, melamine sponge, and ethylene propylene diene rubber sponge. In this embodiment, the pad 10 is substantially flat and rectangular in plan view. The width and length of the pad 10 may be, for example, 10 mm or more and 30 mm or less, or 15 mm or more and 25 mm or less. The thickness t of the pad 10 is 0.5 mm or more and 20 mm or less. The thickness t of the pad 10 may be 1 mm or more and 15 mm or less, 3 mm or more and 10 mm or less, 5 mm or more and 9 mm or less, or 6 mm or more and 8 mm or less.

[0030] Figure 4 is an explanatory diagram showing an example of the time-dependent change in blood pressure value BP measured by the blood pressure measuring device 100. Figure 4 shows the time-dependent change in blood pressure value BP over a period of one heartbeat To. Generally, the curve showing the time-dependent change in blood pressure value BP has a shape in which the ejection wave Ws, the reflected wave (tidal wave) Wt, and the heavy pulse wave Wd are arranged in order. The ejection wave Ws and reflected wave Wt are observed during the systolic phase T1 of the heart, which corresponds to the first half of the pulse, and the heavy pulse wave Wd is observed during the diastolic phase T2 of the heart, which corresponds to the second half of the pulse. In the curve shown in Figure 4, the blood pressure P0 at the start of the pulse is the minimum blood pressure, and the blood pressure P1 at the peak of the ejection wave Ws is the maximum blood pressure. Furthermore, the shape of the curve showing the time-dependent change in blood pressure value BP is determined by the heart's pulsation, valve opening and closing, degree of vascular hardening, blood flow viscosity, etc. Therefore, using known methods, it is possible to predict blood glucose levels, arteriosclerosis status, and cardiovascular events (heart failure, myocardial / cerebral infarction, cardiovascular death, etc.) from, for example, the blood pressure P2 at the peak of the reflected wave Wt, or the AI ​​value (Augmentation Index), which is the ratio of blood pressure P2 to blood pressure P1 (= P2 / P1). Based on the measurement results from the pressure sensor 20, the blood pressure measuring device 100 of this embodiment can display blood glucose levels, pulse rate, and health status on the display 50, in addition to the blood pressure values ​​shown in Figure 1.

[0031] Figure 5 is a perspective view of the main body 30 of the first embodiment, showing the side that does not primarily face the person's wrist WP. Figure 6 is a perspective view of the main body 30 of the first embodiment, showing the side that primarily faces the person's wrist WP. Figure 7 is a front view of the main body 30 of the first embodiment. Figure 8 is a rear view of the main body 30 of the first embodiment. Figure 9 is a left side view of the main body 30 of the first embodiment. Figure 10 is a right side view of the main body 30 of the first embodiment. Figure 11 is a top view of the main body 30 of the first embodiment. Figure 12 is a bottom view of the main body 30 of the first embodiment.

[0032] A space 34 is formed on the side of the main body 30 that does not face the person's wrist WP. The space 34 houses, for example, the aforementioned integrated circuit, the communication interface, and the battery. A display 50 is mounted on the side of the main body 30 that does not face the person's wrist WP so as to cover the integrated circuit, the communication interface, and the battery.

[0033] The main body 30 has a first surface 31 and a second surface 32 on the side facing the human wrist WP. The first surface 31 and the second surface 32 are mainly located on the inner side of the human wrist WP. The first surface 31 and the second surface 32 are joined to each other. When the pressure sensor 20 is pressed against the radial artery BV, the second surface 32 is positioned so as to be aligned with the first surface 31 in the circumferential direction of the radius RA (see Figure 3).

[0034] The first surface 31 is the surface on which the pressure sensor 20 is positioned on the main body 30. More specifically, a recess 36 is formed on the first surface 31. The recess 36 is a recessed portion of the first surface 31 relative to other parts. On the first surface 31, the recess 36 is located relatively close to the second surface 32 in the circumferential direction of the radius RA. A portion of the pad 10 is housed in the recess 36. A portion of the pad 10 protrudes from the recess 36 (see Figure 2). The pressure sensor 20 is positioned on the pad 10.

[0035] The first surface 31 and the second surface 32 are inclined relative to each other so as to follow the body surface SU of a person's wrist WP. Specifically, the second surface 32 is inclined with respect to the first surface 31 when viewed from a direction along the longitudinal direction of the radius RA. The second surface 32 may be inclined with respect to the first surface 31 at an angle of, for example, 80 degrees or more and 150 degrees or less. The second surface 32 is a curved surface that bends in an arc along the circumferential direction of the radius RA. The shape of the second surface 32 follows the thumb side of the medial body surface SU of a person's wrist WP.

[0036] Because the main body 30 has the configuration described above, when the pressure sensor 20 is pressed against the radial artery BV, the pressure sensor 20 and the pad 10 are positioned on the radial artery BV, as shown in Figure 3. More specifically, when the pressure sensor 20 is pressed against the radial artery BV, the first surface 31 of the main body 30 faces the radius RA across the radial artery BV, thereby pressing the pressure sensor 20 toward the radial artery BV. When the pressure sensor 20 is pressed against the radial artery BV, the second surface 32 of the main body 30 covers at least a portion of the styloid process RS of the radius RA, and engages with the styloid process RS of the radius RA to determine the position of the main body 30, and consequently the position of the pressure sensor 20. When the blood pressure measuring device 100 is attached to a person's wrist WP, the pressure sensor 20 outputs a voltage signal indicating the time-dependent change (pressure pulse wave) of the internal pressure (i.e., blood pressure) of the radial artery BV towards the main unit 30. The main unit 30 converts the voltage signal output from the pressure sensor 20 into a blood pressure value. This enables the blood pressure measuring device 100 to measure blood pressure. Furthermore, the presence of the main unit 30 ensures that the position of the pressure sensor 20 in the blood pressure measuring device 100 is fixed on the radial artery BV, allowing for stable measurement of blood pressure values.

[0037] As described above, the main body 30 of this embodiment is for pressing a pressure sensor 20 for measuring changes in blood pressure over time against the radial artery BV. The main body 30 has a first surface 31 on which the pressure sensor 20 is positioned. When the pressure sensor 20 is pressed against the radial artery BV, the first surface 31 faces the radius RA across the radial artery BV. With the main body 30 of this embodiment, since the first surface 31 presses the pressure sensor 20 toward the radial artery BV, changes in blood pressure over time can be accurately measured by the pressure sensor 20 without using a cuff.

[0038] In this embodiment, the main body 30 further has a second surface 32 that is inclined with respect to the first surface 31. When the pressure sensor 20 is pressed against the radial artery BV, the second surface 32 is positioned to align with the first surface 31 in the circumferential direction of the radius RA, and covers at least a portion of the styloid process RS of the radius RA. With the main body 30 of this embodiment, the position of the pressure sensor 20 can be easily determined, so that changes in blood pressure over time can be accurately measured by the pressure sensor 20 without using a cuff.

[0039] In the main body 30 of this embodiment, the second surface 32 is a curved surface that curves along the circumferential direction of the radius RA. With the main body 30 of this embodiment, since the second surface 32 is shaped to conform to the body surface SU of a person's wrist WP, the position of the pressure sensor 20 can be determined more easily, and the change in blood pressure over time can be measured more accurately by the pressure sensor 20 without using a cuff.

[0040] In the main body 30 of this embodiment, the first surface 31 and the second surface 32 are joined to each other. With the main body 30 of this embodiment, the first surface 31 and the second surface 32 are shaped to conform to the body surface SU of a person's wrist WP, making it easier to determine the position of the pressure sensor 20. As a result, the pressure sensor 20 can measure changes in blood pressure over time with greater accuracy without using a cuff.

[0041] The blood pressure measuring device 100 of this embodiment comprises a main body 30 and a pressure sensor 20 arranged on the first surface 31. According to the blood pressure measuring device 100 of this embodiment, since the position of the pressure sensor 20 can be easily determined, the change in blood pressure over time can be accurately measured by the pressure sensor 20 without using a cuff.

[0042] The blood pressure measuring device 100 of this embodiment further includes a pad 10 located between the first surface 31 and the pressure sensor 20, which is made of a porous material with an elastic modulus of 0.1 MPa or less, and the thickness of the pad 10 is 3 mm or more and 10 mm or less. With the blood pressure measuring device 100 of this embodiment, the position of the pressure sensor 20 can be easily determined, so that changes in blood pressure over time can be accurately measured by the pressure sensor 20 without using a cuff.

[0043] In the blood pressure measuring device 100 of the present embodiment, the pressure sensor 20 includes a piezoelectric element. According to the blood pressure measuring device 100 of the present embodiment, it is possible to measure the change over time of blood pressure with the same accuracy as when using a capacitance-type pressure sensor.

[0044] In addition, the main body 30 of the present embodiment does not have a portion along the little finger side of the inner body surface SU on the human wrist WP. Due to such a configuration, according to the main body 30 of the present embodiment, the position of the pressure sensor 20 can be easily determined without limiting the target user.

[0045] (Second Embodiment) FIG. 13 is a perspective view showing the side of the main body 30a of the second embodiment mainly facing the human wrist WP. FIG. 14 is a right side view of the main body 30a of the second embodiment. FIG. 15 is a bottom view of the main body 30a of the second embodiment. The perspective view showing the side of the main body 30a of the second embodiment that does not mainly face the human wrist WP is the same as the perspective view showing the side of the main body 30 of the first embodiment that does not mainly face the human wrist WP shown in FIG. 5. The front view of the main body 30a of the second embodiment is the same as the front view of the main body 30 of the first embodiment shown in FIG. 7. The rear view of the main body 30a of the second embodiment is the same as the rear view of the main body 30 of the first embodiment shown in FIG. 8. The left side view of the main body 30a of the second embodiment is the same as the left side view of the main body 30 of the first embodiment shown in FIG. 9. The plan view of the main body 30a of the second embodiment is the same as the plan view of the main body 30 of the first embodiment shown in FIG. 11. Hereinafter, among the configurations of the main body 30a of the second embodiment, the same configurations as those of the main body 30 of the first embodiment described above will be denoted by the same reference numerals, and their descriptions will be appropriately omitted.

[0046] The main body 30a of the present embodiment has a first surface 31 and a second surface 32a. A concave portion 38 is formed in the second surface 32a. The concave portion 38 is a portion that is recessed more than other portions on the second surface 32a. The concave portion 38 has an elliptical shape extending in the longitudinal direction of the radius RA when viewed in a direction orthogonal to the second surface 32a. The concave portion 38 is located at a position that covers at least a part of the styloid process RS of the radius RA when the pressure sensor 20 is pressed against the radial artery BV.

[0047] As described above, in the main body 30a of the present embodiment, a recess 38 is formed on the second surface 32a, and the recess 38 covers at least a part of the styloid process RS of the radius RA. According to the main body 30a of the present embodiment, since the recess 38 engages with the styloid process RS of the radius RA, the position of the pressure sensor 20 is more easily determined, so that the change over time of blood pressure can be measured more accurately by the pressure sensor 20 without using a cuff.

[0048] (Third Embodiment) FIG. 16 is a perspective view showing mainly the side of the main body 30b of the third embodiment facing a human wrist WP. FIG. 17 is a left side view of the main body 30b of the third embodiment. FIG. 18 is a right side view of the main body 30b of the third embodiment. FIG. 19 is a bottom view of the main body 30b of the third embodiment. The perspective view showing mainly the side of the main body 30b of the third embodiment that does not face a human wrist WP is the same as the perspective view showing mainly the side of the main body 30 of the first embodiment that does not face a human wrist WP shown in FIG. 5. The front view of the main body 30b of the third embodiment is the same as the front view of the main body 30 of the first embodiment shown in FIG. 7. The rear view of the main body 30b of the third embodiment is the same as the rear view of the main body 30 of the first embodiment shown in FIG. 8. The plan view of the main body 30b of the third embodiment is the same as the plan view of the main body 30 of the first embodiment shown in FIG. 11. Hereinafter, among the configurations of the main body 30b of the third embodiment, the same configurations as those of the main body 30a of the second embodiment described above will be denoted by the same reference numerals, and the description thereof will be appropriately omitted.

[0049] The main body portion 30b of this embodiment has a first surface 31 and a second surface 32b. A recess 38b is formed on the second surface 32b. The recess 38b is a portion that is recessed compared to the rest of the second surface 32b. The shape of the recess 38b differs from that of the recess 38 in the second embodiment. The recess 38b is half-dome shaped. In detail, the recess 38b is half-dome shaped such that, when viewed in a direction perpendicular to the second surface 32b, the width of the recess 38b widens in the longitudinal direction of the radius RA as the distance from the first surface 31 increases, and the recess of the recess 38b becomes larger. The recess 38b is positioned to cover at least a portion of the styloid process RS of the radius RA when the pressure sensor 20 is pressed against the radial artery BV. As with the main body portion 30b of this embodiment, the shape of the recess formed on the second surface may be half-dome shaped.

[0050] (Fourth Embodiment) Figure 20 is a perspective view of the main body 30c of the fourth embodiment, showing the side that primarily faces a person's wrist WP. Figure 21 is a left side view of the main body 30c of the fourth embodiment. Figure 22 is a right side view of the main body 30c of the fourth embodiment. Figure 23 is a bottom view of the main body 30c of the fourth embodiment. The perspective view of the main body 30c of the fourth embodiment, showing the side that does not primarily face a person's wrist WP, is the same as the perspective view of the main body 30 of the first embodiment, shown in Figure 5. The front view of the main body 30c of the fourth embodiment is the same as the front view of the main body 30 of the first embodiment, shown in Figure 7. The rear view of the main body 30c of the fourth embodiment is the same as the rear view of the main body 30 of the first embodiment, shown in Figure 8. The plan view of the main body 30c of the fourth embodiment is the same as the plan view of the main body 30 of the first embodiment shown in Figure 11. In the following, for the components of the main body 30c of the fourth embodiment that are the same as those of the main body 30a of the second embodiment described above, the same reference numerals are used, and their descriptions will be omitted as appropriate.

[0051] The main body portion 30c of this embodiment has a first surface 31 and a second surface 32c. A recess 38c is formed on the second surface 32c. The recess 38c is a recessed portion of the second surface 32c that is more recessed than the rest of the second surface 32c. The shape of the recess 38c differs from that of the recess 38 in the second embodiment and the recess 38b in the third embodiment. The recess 38c is a quarter-dome type. In detail, the recess 38c is a quarter-dome type in which, when viewed in a direction perpendicular to the second surface 32c, the width of the recess 38c widens in the longitudinal direction of the radius RA as the distance from the first surface 31 increases, and the recess of the recess 38c becomes larger. The recess 38c is positioned to cover at least a portion of the styloid process RS of the radius RA when the pressure sensor 20 is pressed against the radial artery BV. As with the main body portion 30c of this embodiment, the shape of the recess formed on the second surface may be a quarter-dome type.

[0052] (Fifth Embodiment) Figure 24 is a perspective view of the main body portion 30d of the fifth embodiment, showing the side that does not primarily face the person's wrist WP. Figure 25 is a perspective view of the main body portion 30d of the fifth embodiment, showing the side that primarily faces the person's wrist WP. Figure 26 is a front view of the main body portion 30d of the fifth embodiment. Figure 27 is a rear view of the main body portion 30d of the fifth embodiment. Figure 28 is a left side view of the main body portion 30d of the fifth embodiment. Figure 29 is a right side view of the main body portion 30d of the fifth embodiment. Figure 30 is a top view of the main body portion 30d of the fifth embodiment. Figure 31 is a bottom view of the main body portion 30d of the fifth embodiment. Hereinafter, for the components of the main body portion 30d of the fifth embodiment that are the same as those of the main body portion 30 of the first embodiment described above, their descriptions will be appropriately omitted by using the same reference numerals.

[0053] The main body 30d of this embodiment has a first surface 31, a second surface 32, and a third surface 33 on the side facing the human wrist WP. The first surface 31, the second surface 32, and the third surface 33 are mainly located on the inner side of the human wrist WP. The third surface 33 is located on the opposite side of the second surface 32, with the first surface 31 in between. The first surface 31 and the third surface 33 are joined to each other. The third surface 33 is positioned so as to be aligned with the first surface 31 in the circumferential direction of the radius RA.

[0054] The first surface 31 and the third surface 33 are inclined relative to each other so as to follow the body surface SU of a person's wrist WP. Specifically, the third surface 33 is inclined with respect to the first surface 31 when viewed from a direction along the longitudinal direction of the radius RA. The third surface 33 is a curved surface that curves in an arc along the circumferential direction of the radius RA. The shape of the third surface 33 follows the little finger side of the inner body surface SU of a person's wrist WP. In other words, the main body portion 30d has a space 35 formed by the first surface 31, the second surface 32, and the third surface 33. The space 35 is a space for accommodating at least a part of the wrist WP when the blood pressure measuring device 100 is attached to a person's wrist WP. Note that, in this embodiment, the main body portion 30d may have a recess formed in the second surface 32, similar to the main body portion 30a of the second embodiment, the main body portion 30b of the third embodiment, and the main body portion 30c of the fourth embodiment.

[0055] The first distance D1, which is the distance between end 32E1, the end of the second surface 32 located opposite to the first surface 31, and end 33E1, the end of the third surface 33 located opposite to the first surface 31, is equal to the distance from end ER of the styloid process RS of the radius RA to end EU of the styloid process US of the ulna UL of the subject user. More specifically, for example, if the subject user is an adult, the first distance D1 is equal to the average distance from end ER of the styloid process RS of the radius RA to end EU of the styloid process US of the ulna UL of the adult. End ER means the lateral end (i.e., in the direction parallel to the palm) of the styloid process RS. End EU means the lateral end of the styloid process US. In this specification, "equal" includes "approximately equal," where "approximately equal" means that the difference between the two values ​​being compared is 10% or less of the larger value. The first distance D1 may be, for example, 42 mm or more and 65 mm or less.

[0056] In the direction connecting the end 32E1 on the second surface 32 and the end 33E1 on the third surface 33, the second distance D2, which is the distance between end 32E2, which is the end on the second surface 32 located on the same side as the first surface 31, and end 32E1, is at least one-tenth and at least one-fifth of the first distance D1. The second distance D2 may be, for example, at least 4.2 mm and at least 13 mm.

[0057] The third distance D3, which is the shortest distance between the imaginary straight line VL connecting the end 32E1 on the second surface 32 and the end 33E1 on the third surface 33 and the first surface 31, is between one-quarter and one-third of the thickness of the target user's wrist WP. More specifically, for example, if the target user is an adult, the third distance D3 is equal to the average thickness of the wrist WP. The thickness of the wrist WP is the thickness of the wrist WP in the longitudinal direction of the radius RA and ulna UL at a position closer to the palm than the styloid process RS and styloid process US (i.e., the length in the direction perpendicular to the palm). The third distance D3 may be, for example, between 7.8 mm and 17.3 mm. Also, the radius of the imaginary arc VA along the shape of the second surface 32 is the same as or greater than the third distance D3.

[0058] As described above, the main body 30d of this embodiment further has a third surface 33 located on the opposite side of the second surface 32, with the first surface 31 in between, and inclined with respect to the first surface 31, forming a space 35 enclosed by the first surface 31, the second surface 32, and the third surface 33. With the main body 30d of this embodiment, the position of the pressure sensor 20 can be more easily determined because the person's wrist WP is housed in the space 35, so that changes in blood pressure over time can be measured more accurately by the pressure sensor 20 without using a cuff.

[0059] In the main body 30d of this embodiment, the first distance D1, which is the distance between the end 32E1 on the second surface 32 that is on the opposite side of the first surface 31 and the end 33E1 on the third surface 33 that is on the opposite side of the first surface 31, is equal to the distance from the end ER of the styloid process RS of the radius RA of the target user to the end EU of the styloid process US of the ulna UL. With the main body 30d of this embodiment, the space 35 is shaped to better match the body surface SU of the person's wrist WP, making it easier to determine the position of the pressure sensor 20, and thus enabling more accurate measurement of changes in blood pressure over time by the pressure sensor 20 without using a cuff.

[0060] In the main body portion 30d of this embodiment, the second distance D2, which is the distance between the end portion 32E2 on the same side as the first surface 31 on the second surface 32 and the end portion 32E1 on the opposite side of the first surface 31 on the second surface 32, in the direction connecting the end portion 32E1 on the second surface 32 opposite to the first surface 31 and the end portion 33E1 on the third surface 33 opposite to the first surface 31, is one-tenth or more and one-fifth or less of the first distance D1. According to the main body portion 30d of this embodiment, the space 35 is shaped to better match the body surface SU of a person's wrist WP, making it easier to determine the position of the pressure sensor 20, and thus enabling more accurate measurement of changes in blood pressure over time by the pressure sensor 20 without using a cuff.

[0061] In the main body portion 30d of this embodiment, the third distance D3, which is the shortest distance between the virtual straight line VL connecting the end portion 32E1 on the second surface 32 opposite to the first surface 31 and the end portion 33E1 on the third surface 33 opposite to the first surface 31, and the first surface 31, is between one-quarter and one-third of the thickness of the target user's wrist WP. With the main body portion 30d of this embodiment, the space 35 is shaped to better match the body surface SU of a person's wrist WP, making it easier to determine the position of the pressure sensor 20. As a result, the pressure sensor 20 can measure changes in blood pressure over time with greater accuracy without using a cuff.

[0062] In the main body 30d of this embodiment, the second surface 32 is a curved surface that curves in an arc along the circumferential direction of the radius RA, and the radius of the virtual arc VA along the shape of the second surface 32 is the same as or greater than the third distance D3. According to the main body 30d of this embodiment, the space 35 is shaped to better match the body surface SU of the human wrist WP, making it easier to determine the position of the pressure sensor 20, and thus enabling more accurate measurement of changes in blood pressure over time by the pressure sensor 20 without using a cuff.

[0063] (Modifications) The technologies disclosed herein are not limited to the embodiments described above and can be modified in various forms without departing from the spirit thereof, for example, the following modifications are possible.

[0064] The configuration of the blood pressure measuring device 100 in the above embodiment is merely an example and can be modified in various ways. For example, the shape of the main body 30 is merely an example and can be modified in various ways.

[0065] In the above embodiment, the second surface 32 is a curved surface that curves along the circumferential direction of the radius RA, but the second surface may be a flat surface.

[0066] The dimensions of the first distance D1, the second distance D2, and the third distance D3 in the above embodiment are merely examples.

[0067] In the above embodiment, the main body 30 has a first surface 31 and a second surface 32, but the pressing device only needs to have at least a first surface.

[0068] 10: Pad for pressure sensor 20: Pressure sensor 30, 30a-30d: Main body 31: First surface 32, 32a-32d: Second surface 33: Third surface 34: Space 35: Space 36: Recess 38, 38b-38d: Recess 40: Band 50: Display 100: Blood pressure measuring device WP: Wrist BV: Radial artery RA: Radius RS: Styloid process UL: Ulna US: Styloid process SU: Body surface ER: End EU: End t: Thickness BP: Blood pressure value P0: Blood pressure P1: Blood pressure P2: Blood pressure To: Period T1: Systolic T2: Diastolic Ws: Ejection wave Wt: Reflected wave Wd: Heavy pulse wave

Claims

1. A pressing device for pressing a pressure sensor for measuring changes in blood pressure over time against a radial artery, the pressing device having a first surface on which the pressure sensor is positioned, wherein when the pressure sensor is pressed against the radial artery, the first surface faces the radius with the radial artery in between.

2. A pressing device according to claim 1, further comprising a second surface inclined with respect to the first surface, wherein when the pressure sensor is pressed against the radial artery, the second surface is positioned to be aligned with the first surface in the circumferential direction of the radius and covers at least a portion of the styloid process of the radius.

3. The pressing device according to claim 2, wherein the second surface is a curved surface that bends along the circumferential direction of the radius.

4. A pressing device according to claim 2 or claim 3, wherein a recess is formed on the second surface, and the recess covers at least a portion of the styloid process of the radius.

5. A pressing device according to claim 2 or claim 3, wherein the first surface and the second surface are joined to each other.

6. A pressing device according to claim 2 or claim 3, further comprising a third surface located on the opposite side of the second surface with respect to the first surface, and inclined with respect to the first surface, thereby forming a space enclosed by the first surface, the second surface and the third surface.

7. A pressing device according to claim 6, wherein the first distance, which is the distance between the end of the second surface located on the opposite side of the first surface and the end of the third surface located on the opposite side of the first surface, is equal to the distance from the end of the styloid process of the radius of the target user to the end of the styloid process of the ulna.

8. A pressing device according to claim 7, wherein, in the direction connecting the end of the second surface located on the opposite side of the first surface and the end of the third surface located on the opposite side of the first surface, the second distance, which is the distance between the end of the second surface located on the same side of the first surface and the end of the second surface located on the opposite side of the first surface, is one-tenth or more and one-fifth or less of the first distance.

9. A pressing device according to claim 6, wherein the third distance, which is the shortest distance between the imaginary straight line connecting the end of the second surface located on the opposite side of the first surface and the end of the third surface located on the opposite side of the first surface and the first surface, is one-quarter or more and one-third or less of the thickness of the target user's wrist.

10. A pressing device according to claim 9, wherein the second surface is a curved surface that curves in an arc along the circumferential direction of the radius, and the radius of a virtual arc along the shape of the second surface is the same as or greater than the third distance.

11. A blood pressure measuring device comprising: a pressing device according to claim 1 or claim 2; and the pressure sensor disposed on the first surface.

12. A blood pressure measuring device according to claim 11, further comprising a pressure sensor pad located between the first surface and the pressure sensor, the pressure sensor pad being made of a porous material having an elastic modulus of 0.1 MPa or less, and having a thickness of 3 mm or more and 10 mm or less.

13. A blood pressure measuring device according to claim 11, wherein the pressure sensor comprises a piezoelectric element.

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