Pulse wave measurement device

Abstract

The present invention provides a pulse wave measurement device that enables a pulse wave sensor to be appropriately placed with respect to a radial artery regardless of the length of the circumference of a wrist. A pulse wave measurement device (100) comprises: a first arm (10) and a second arm (20) that are capable of swinging relative to each other around a first axis which extends in a first direction along the longitudinal direction of a radial artery (110); a pulse wave sensor (31) that is mounted in a distal end portion of the first arm (10); and a movable part (40) that is connected to the second arm and that is movable in a direction approaching or separating from the pulse wave sensor.

Description

Pulse wave measuring device

[0001] The present disclosure relates to a pulse wave measuring device.

[0002] For example, an electrode holder that holds a biological electrode that contacts a target part of the body is known (see, for example, Patent Document 1). This electrode holder includes a first arm and a second arm that are opened and closed by rotating relatively around a rotation fulcrum to bring the electrode into contact with the target part, and a biasing member that biases the first arm and the second arm in a direction to close them.

[0003] Japanese Patent Application Laid-Open No. 2020-163012

[0004] For example, pulse wave measuring devices equipped with a pulse wave sensor that detects pulse waves generated when the heart pumps blood are known. Such pulse wave measuring devices are worn, for example, on the wrist of a subject. Because the pulse wave sensor must detect minute signals, it is preferable to position the sensor appropriately with respect to the subject's radial artery to improve measurement accuracy. Because wrist circumference varies from person to person, it is necessary to position the pulse wave sensor appropriately regardless of wrist circumference.

[0005] An object of the present disclosure is to provide a pulse wave measuring device that allows a pulse wave sensor to be appropriately positioned with respect to the radial artery regardless of the circumference of the wrist.

[0006] A pulse wave measuring device according to one embodiment of the present disclosure includes a first arm and a second arm that can swing relatively around a first axis extending in a first direction along the longitudinal direction of the radial artery, a pulse wave sensor mounted on the tip of the first arm, and a movable part that is connected to the second arm and can move in a direction toward or away from the pulse wave sensor.

[0007] According to the technique of the present disclosure, it is possible to provide a pulse wave measuring device that allows the pulse wave sensor to be appropriately positioned with respect to the radial artery regardless of the circumference of the wrist.

[0008] Fig. 1 is a side view illustrating a pulse wave measurement device according to an embodiment; Fig. 2 is a perspective view illustrating a pulse wave measurement device according to an embodiment, showing a state in which a movable part does not protrude; Fig. 3 is a perspective view illustrating a pulse wave measurement device according to an embodiment, showing a state in which a movable part protrudes; Fig. 4 is a side view illustrating a second arm and a movable part; Fig. 5 is a perspective view illustrating a pulse wave measurement device according to an embodiment, showing the second arm from the outer surface side;

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes the preferred embodiments of the present invention with reference to the accompanying drawings. In the drawings, the same components are designated by the same reference numerals, and redundant explanations may be omitted.

[0010] [Pulse wave measurement device 100 according to an embodiment] FIG. 1 is a side view illustrating the pulse wave measurement device 100 according to an embodiment. FIG. 2 is a perspective view illustrating the pulse wave measurement device 100 according to an embodiment, showing a state in which the movable part 40 does not protrude. FIG. 3 is a perspective view illustrating the pulse wave measurement device 100 according to an embodiment, showing a state in which the movable part 40 protrudes. FIG. 4 is a side view illustrating the second arm 20 and the movable part 40. FIG. 5 is a perspective view illustrating the pulse wave measurement device 100 according to an embodiment, showing the second arm from the outer surface side. Note that each figure shows an X-axis direction, a Y-axis direction, and a Z-axis direction that are orthogonal to one another. The Y-axis direction is along a first direction, which is the longitudinal direction of the radial artery.

[0011] In addition, in each figure, the direction indicated by an arrow may be referred to as the positive direction, and the opposite direction may be referred to as the negative direction. The X-axis direction includes the positive X-axis direction and the negative X-axis direction. The positive X-axis direction and the negative X-axis direction are opposite directions. The Y-axis direction includes the positive Y-axis direction and the negative Y-axis direction. The positive Y-axis direction and the negative Y-axis direction are opposite directions. The Z-axis direction includes the positive Z-axis direction and the negative Z-axis direction. The positive Z-axis direction and the negative Z-axis direction are opposite directions.

[0012] 1 to 3 is a wearable device that can be attached to a subject. The pulse wave measuring device 100 is attached to the subject's wrist 112, for example, so that the pulse wave sensor 31 having a strain-generating body is in contact with the skin above the subject's radial artery 110. A pulse wave is a waveform that captures changes in the volume of blood vessels that occur as the heart pumps blood, and the pulse wave measuring device 100 can monitor changes in the volume of blood vessels.

[0013] The pulse wave measuring device 100 includes a first arm 10, a second arm 20, a pulse wave sensor 31, and a movable part 40. The pulse wave measuring device 100 may be a clip-type pulse wave measuring device 100 that clamps the wrist 112 of the subject with the first arm 10 and the second arm 20. The pulse wave measuring device 100 includes a swing shaft 52, and the first arm 10 and the second arm 20 are swingable around the swing shaft 52.

[0014] [Pulse wave sensor mounting unit 30] The pulse wave measurement device 100 includes a pulse wave sensor mounting unit 30 that mounts a pulse wave sensor 31. The pulse wave sensor 31 detects the pulse wave of the subject. The pulse wave sensor mounting unit 30 is provided at the distal end 11 of the first arm 10. The pulse wave sensor mounting unit 30 may include an attitude adjustment mechanism that can adjust the attitude of the pulse wave sensor 31.

[0015] [Swing axis 52] The swing axis 52 extends along the Y-axis direction. The Y-axis direction is the direction in which the radial artery 110 extends. The first arm 10 and the second arm 20 can swing around the swing axis 52. The swing axis 52 is an example of a first axis. The first arm 10 and the second arm 20 can swing relatively around the swing axis 52. Being relatively swingable means that at least one of the first arm 10 and the second arm 20 can swing around the swing axis 52.

[0016] [First Arm 10] The first arm 10 is arranged along the circumference of the wrist 112, closer to the palm. The first arm 10 is curved so as to be convex toward the positive direction of the Z axis when viewed in the Y axis direction. The longitudinal direction of the first arm 10 is arranged along the circumferential direction of the wrist 112. The first arm 10 has a predetermined width in the Y axis direction. The first arm 10 may include a plate-like portion having a predetermined thickness. The first arm 10 may also have a rib that protrudes in the thickness direction. The first arm 10 may have multiple ribs arranged at a distance in the Y axis direction. The ribs may be a pair of side plates 60a, which will be described later.

[0017] The first arm 10 has a tip end 11 and a base end 12. The base end 12 is the end closer to the oscillation shaft 52 in the longitudinal direction of the first arm 10, and the tip end 11 is the end farther from the oscillation shaft 52.

[0018] The first arm 10 may include a linearly extending portion and a curved portion when viewed in the Y-axis direction. The first arm 10 may include a first portion extending linearly away from the swing shaft 52, a second portion curved from the first portion, and a third portion extending linearly from the second portion. The first arm 10 may be formed to be curved as a whole, or may have a shape in which multiple straight lines are connected continuously at any angle. In the thickness direction of the first arm 10, the surface closer to the wrist 112 is the inner surface, and the surface farther from the wrist 112 is the outer surface.

[0019] [Second Arm 20] The second arm 20 is arranged along the circumference of the wrist 112, closer to the back of the hand. The second arm 20 is arranged to face the first arm 10, with the wrist 112 in between. The second arm 20 is curved so as to be convex toward the negative Z-axis direction when viewed in the Y-axis direction. The longitudinal direction of the second arm 20 is arranged along the circumferential direction of the wrist 112. The second arm 20 has a predetermined width in the Y-axis direction. The second arm 20 may include a plate-shaped portion having a predetermined thickness. The second arm 20 may also have ribs that protrude in the thickness direction. The second arm 20 may have ribs arranged spaced apart in the Y-axis direction.

[0020] The second arm 20 has a tip end 21 and a base end 22. The base end 22 is the end closer to the swing shaft 52 in the longitudinal direction of the second arm 20, and the tip end 21 is the end farther from the swing shaft 52.

[0021] 4, the second arm 20 may include a portion that extends linearly in the X-axis direction and a portion that is curved in a curved manner when viewed in the Y-axis direction. The second arm 20 may include a first portion that extends linearly away from the swing axis 52, a second portion that is bent from the first portion away from the first arm 10 and curves to fit around the wrist 112, a third portion that is continuous with the second portion and extends linearly, and a fourth portion that is continuous with the third portion and curves to fit around the wrist 112. The second arm 20 may be formed to be curved overall, or may have a shape in which multiple straight lines are connected continuously at any angle.

[0022] 1 to 3, the pulse wave measurement device 100 includes a first operation unit 13 and a second operation unit 23. The first operation unit 13 is connected to the base end 12 of the first arm 10 and extends on the opposite side from the first arm 10. The first operation unit 13 is, for example, molded integrally with the first arm 10 and swings together with the first arm 10. The first operation unit 13 is swingable around a swing axis 52. The first arm 10 and the first operation unit 13 are formed, for example, from resin. Note that the material of the pulse wave measurement device 100 is not limited.

[0023] The second operating unit 23 is connected to the base end 22 of the second arm 20 and extends on the opposite side to the second arm 20. The second operating unit 23 is, for example, molded integrally with the second arm 20 and swings together with the second arm 20. The second operating unit 23 is swingable around a swing shaft 52. The second arm 20 and the second operating unit 23 are formed, for example, from resin.

[0024] [Open State of Pulse Wave Measurement Device 100] In the pulse wave measurement device 100, the first operating unit 13 and the second operating unit 23 can be operated to move closer to each other. By swinging the first operating unit 13 and the second operating unit 23 closer to each other, the tip 11 of the first arm 10 and the tip 21 of the second arm 20 move apart from each other. The state in which the tip 11 of the first arm 10 and the tip 21 of the second arm 20 are separated from each other is the open state of the pulse wave measurement device 100. When wearing the pulse wave measurement device 100 on the wrist 112, the wrist 112 can be clamped by the first arm 10 and the second arm 20 after the pulse wave measurement device 100 is in the open state.

[0025] [Closed State of Pulse Wave Measurement Device 100] In the pulse wave measurement device 100, the first operating unit 13 and the second operating unit 23 can be operated to move apart. By swinging the first operating unit 13 and the second operating unit 23 apart, the tip 11 of the first arm 10 and the tip 21 of the second arm 20 move closer to each other. The state in which the tip 11 of the first arm 10 and the tip 21 of the second arm 20 are close to each other is referred to as the closed state of the pulse wave measurement device 100. The state in which the pulse wave measurement device 100 is worn on the wrist 112 is referred to as the closed state of the pulse wave measurement device 100. While the pulse wave measurement device 100 is measuring a pulse wave, the pulse wave measurement device 100 is in the closed state.

[0026] [Using Member 50] The pulse wave measurement device 100 includes the urging member 50. The urging member 50 urges at least one of the first arm 10 and the second arm 20 in a direction toward each other. The urging member 50 may be, for example, a wire spring. The urging member 50 may be a leaf spring, a torsion spring, or any other spring. The urging member 50 is formed, for example, from metal. The urging member 50 has a predetermined length. One longitudinal end of the urging member 50 is connected to the first arm 10, and the other longitudinal end is connected to the second arm 20. The urging member 50 may be connected to the first arm 10 or the second arm 20 via another member.

[0027] 1 to 5, the pulse wave measurement device 100 includes a movable part 40 that is connected to the second arm 20 and is movable relative to the second arm 20. The movable part 40 is movable in a direction toward or away from the pulse wave sensor 31 as viewed in the Y-axis direction. FIG. 1 and FIGS. 3 to 5 show a state in which the movable part 40 is approaching the pulse wave sensor 31. FIG. 2 shows a state in which the movable part 40 is away from the pulse wave sensor 31.

[0028] [First, Second, and Third States of the Movable Unit 40] The first state is the state in which the movable unit 40 is closest to the pulse wave sensor 31, and a receiving portion 45 (described later) of the movable unit 40 abuts against the outer surface of the second arm 20. As shown in FIG. 2 , the third state is the state in which the movable unit 40 is farthest from the pulse wave sensor 31, and a push plate 42 (described later) of the movable unit 40 is housed in the second arm 20. As shown in FIG. 1 and FIGS. 3 to 5 , the second state is the state in which the movable unit 40 is positioned intermediate between the first and third states. In this way, the movable unit 40 can move (swing) between the first, second, and third states.

[0029] [Second Oscillating Shaft 41] The movable part 40 has a second oscillating shaft 41. The second oscillating shaft 41 extends along the Y-axis direction. The movable part 40 is oscillating around the second oscillating shaft 41. The second oscillating shaft 41 is an example of a second shaft. The second oscillating shaft 41 is disposed on the opposite side of the radial artery 110 from the pulse wave sensor 31. For example, the distance from the radial artery 110 to the second oscillating shaft 41 is greater than the distance from the radial artery 110 to the pulse wave sensor 31. The movable part 40 is held by the second arm 20. The movable part 40 is disposed in a middle portion of the second arm 20 in the longitudinal direction. The middle portion of the second arm 20 may be disposed in a middle portion between the distal end portion 21 and the proximal end portion 22.

[0030] [Push Plate 42] The movable part 40 includes a push plate 42 and an overhang 43. The push plate 42 extends in a direction along part of the circumference of the wrist 112. The push plate 42 can abut against part of the circumference of the wrist 112. When viewed in the Y-axis direction, the push plate 42 is curved along part of the circumference of the wrist 112. The push plate 42 has a tip end 42a and a base end 42b in the longitudinal direction of the push plate 42. In the thickness direction of the second arm 20, the surface of the push plate 42 closer to the wrist 112 is the inner surface, and the surface away from the wrist 112 is the outer surface. The inner surface of the push plate 42 can abut against the circumference of the wrist 112.

[0031] The base end 42b of the push plate 42 is the end closest to the second swing shaft 41, and the tip end 42a is the end farther from the second swing shaft 41. The base end 42b is connected to the second swing shaft 41. An opening is formed in the base end 42b to allow the second swing shaft 41 to pass through. The push plate 42 is supported by the second arm 20 so as to be swingable around the second swing shaft 41.

[0032] 2 and 3, the width of the push plate 42 may be narrower than the width of the second arm 20. The widths of the second arm 20 and the push plate 42 are widths along the Y-axis direction. In the third state shown in Fig. 2, the push plate 42 is housed in the second arm 20. The second arm 20 may have a recess (step surface) formed therein that can house the push plate 42.

[0033] 1 to 5, the protruding portion 43 protrudes from the push plate 42 to the side opposite the wrist 112. An opening through which the protruding portion 43 is inserted may be formed in the second arm 20. The protruding portion 43 penetrates the second arm 20 and protrudes to the outer surface side of the second arm 20. The protruding portion 43 is formed so as to intersect with the second arm 20 when viewed in the Y-axis direction. The push plate 42 and the protruding portion 43 may be formed, for example, so as to form an inverted Y shape when viewed in the Y-axis direction.

[0034] The protruding portion 43 has a base end portion closer to the push plate 42 and a tip end portion 43a farther from the push plate 42. The tip end portion 43a is the end portion opposite the push plate 42. The movable portion 40 includes, for example, a pair of protruding portions 43. The pair of protruding portions 43 are formed apart in the Y-axis direction.

[0035] [Receiving portion 45] The movable portion 40 includes a receiving portion 45. The receiving portion 45 extends in the Y-axis direction and connects the tip ends 43a of the pair of overhanging portions 43. The receiving portion 45 may be, for example, a rod-shaped member. Both longitudinal ends of the receiving portion 45 are fixed to the tip ends 43a of the pair of overhanging portions 43, respectively. The receiving portion 45 is fastened to the tip ends 43a of the overhanging portions 43, for example, by screws.

[0036] The other end 50b of the biasing member 50 is connected to the receiving portion 45. The end 50b of the biasing member 50 is connected to the second arm 20 via the receiving portion 45, the protruding portion 43, the push plate 42, and the second swing shaft 41. In other words, the biasing force of the biasing member 50 on the receiving portion 45 is transmitted from the receiving portion 45 to the second arm 20 via the protruding portion 43, the push plate 42, and the second swing shaft 41. The movable portion 40 can swing around the second swing shaft 41, but is always biased by the biasing member 50 toward the pulse wave sensor 31. The movable portion 40 is biased by the biasing member 50 and can be displaced. The movable portion 40 can be displaced between a first state, a second state, and a third state.

[0037] In the third state, the receiving portion 45 is disposed at a position farthest from the second arm 20. In the first state, the receiving portion 45 abuts against the outer surface of the second arm 20. The receiving portion 45 abuts against the outer surface of the second arm 20, thereby restricting the range of movement of the movable portion 40.

[0038] In the third state, the push plate 42 abuts against the inner surface of the second arm 20. The push plate 42 abutting against the inner surface of the second arm 20 restricts the movement of the movable part 40 in a direction away from the pulse wave sensor 31.

[0039] Wearing the Pulse Wave Measurement Device 100 (For Thin Wrist) Next, a procedure for wearing the pulse wave measurement device 100 for a thin wrist will be described with reference to Figures 1, 3, and 4. First, when the pulse wave measurement device 100 is not worn on the wrist 112 and the first arm 10 and the second arm 20 are in the closed state, the movable unit 40 is in the third state. In this state, the push plate 42 is constantly biased toward the pulse wave sensor 31 by the biasing member 50, so that the receiving portion 45 abuts against the outer surface of the second arm 20. Thereafter, by operating the first operating unit 13 and the second operating unit 23 to open the first arm 10 and the second arm 20, the pulse wave measurement device 100 can be worn on the wrist 112. When wearing the device, the circumference of the wrist 112 farthest from the radial artery 110 is placed against the inner surface of the push plate 42, and the push plate 42 is then pressed in a direction against the biasing direction of the biasing member 50, causing the push plate 42 to swing in a direction away from the pulse wave sensor 31.

[0040] Next, the pulse wave measuring device 100 can be attached by sliding the wrist 112 so that the circumference thereof near the radial artery 110 and the back of the hand abuts against the distal end 21 of the second arm 20. At this time, as described above, the push plate 42 is constantly biased toward the pulse wave sensor 31 by the biasing member 50, so the wrist 112 is pushed by the push plate 42 so as to eliminate any gap between the wrist 112 and the distal end 21 of the second arm 20. As a result, even if the wrist is thin, the push plate 42 can move to accommodate the thinness of the wrist, making it possible to appropriately position the pulse wave sensor 31 with respect to the radial artery 110 regardless of the circumference of the wrist 112. Note that a state in which the pulse wave measuring device 100 is attached to the wrist 112 and the receiving portion 45 is separated from the outer surface of the second arm 20 and the push plate 42 is not abutting against the inner surface of the second arm 20 is referred to as a second state.

[0041] For example, in the second state, a portion of the second arm 20 closer to the tip 21 and a portion of the push plate 42 abut against the circumferential surface of the wrist 112. The pulse wave measurement device 100 is appropriately positioned with respect to the wrist 112, and the pulse wave sensor 31 is disposed near the radial artery 110. In this state, the second arm 20 and the push plate 42 abut against the circumferential surface of the wrist 112, thereby increasing the contact area. This increases the frictional resistance generated between the wrist 112 and the second arm 20, and between the wrist 112 and the push plate 42, and therefore has the effect of making it difficult for the pulse wave measurement device 100 to rotate around the wrist 112, even if the center of gravity of the pulse wave measurement device 100 is misaligned with the axis of the wrist 112.

[0042] Wearing the Pulse Wave Measurement Device 100 (For a Thick Wrist) Next, with reference to FIG. 2 , wearing the pulse wave measurement device 100 when the wrist 112 is thick will be described. The procedure for wearing the pulse wave measurement device 100 is the same as described above regardless of the thickness of the wrist 112. However, when the wrist 112 is as thick as shown in FIG. 2 , the movable unit 40 may not remain in the second state but may enter the third state. That is, depending on the thickness of the wrist 112, the push plate 42 of the movable unit 40 may be pushed down in a direction away from the radial artery 110 against the biasing force of the biasing member 50 and may come into contact with the inner surface of the second arm 20. The push plate 42 abuts against the circumferential surface of the wrist 112 and moves toward the second arm 20. Specifically, the tip 42 a of the push plate 42 moves toward the base end 22 of the second arm 20.

[0043] [Movement of Movable Part 40 in the Direction Approaching Pulse Wave Sensor 31] As described above, the movable part 40 can be displaced from the first state to the second state and from the second state to the third state. In the first state, which is the initial state of the pulse wave measurement device 100, the push plate 42 is positioned closest to the pulse wave sensor 31. For example, when a person with a thick wrist wears the pulse wave measurement device 100 and then removes the pulse wave measurement device 100 from the wrist, the push plate 42 moves in the direction approaching the pulse wave sensor 31. In other words, the push plate 42 moves in the direction approaching the radial artery 110. The push plate 42 is urged by the urging member 50 to move away from the second arm 20 and approach the circumferential surface of the wrist 112. As a result, when the pulse wave measurement device 100 is worn on the wrist 112, the push plate 42 can abut against the circumferential surface of the wrist 112.

[0044] [Movement of Movable Part 40 in a Direction Away from Pulse Wave Sensor 31] For example, when the movable part 40 is displaced from the first state, which is the initial state, to the second state or the third state, the push plate 42 of the movable part 40 moves in a direction away from the pulse wave sensor 31. By wearing the pulse wave measuring device 100 on the wrist 112, the user can move the push plate 42 in a direction away from the pulse wave sensor 31.

[0045] [Board Mounting Section 60] The first arm 10 has a board mounting section 60 on which a wiring board 61 electrically connected to the pulse wave sensor 31 is mounted. The first arm 10 includes a pair of side plates 60a spaced apart in the width direction of the first arm 10. The wiring board 61 is mounted between the pair of side plates 60a. The board mounting section 60 may also be a housing section that houses the wiring board 61. The wiring board 61 is covered by a cover 62. The cover 62 is fixed to the pair of side plates 60a.

[0046] For example, components that contribute to pulse wave detection are arranged on the wiring board 61. Examples of such components include an amplifier circuit that amplifies the output of the strain gauge, an AD converter that converts the output of the amplifier circuit into a digital signal, a semiconductor for signal processing that processes the digital signal, and a semiconductor for wireless communication that transmits the results of signal processing to the outside. A cable 63 may be connected to the wiring board 61. The cable 63 may be used for supplying power and inputting and outputting electrical signals to and from an external circuit. Note that power may be supplied by a battery instead of the cable 63.

[0047] Moreover, one end 50a of the biasing member 50 may be fixed to the cover 62. The biasing member 50 is connected to the first arm 10 via the cover 62.

[0048] [Action and effect of pulse wave measuring device 100 according to embodiment] The pulse wave measuring device 100 according to the embodiment comprises a first arm 10 and a second arm 20 that can swing relatively around a swing axis (first axis) 52 that extends in the Y-axis direction (first direction) along the longitudinal direction of the radial artery 110, a pulse wave sensor 31 mounted on the tip 11 of the first arm 10, and a movable part 40 that is connected to the second arm 20 and can move in a direction toward or away from the pulse wave sensor 31.

[0049] With this pulse wave measuring device 100, the movable part 40 can be moved to position the pulse wave sensor 31 relative to the radial artery 110 regardless of the thickness of the wrist 112. By moving the movable part 40 in a direction toward or away from the pulse wave sensor 31, the second arm 20 and the movable part 40 can be fitted to fit along the circumferential surface of the wrist 112 regardless of the thickness of the wrist 112. In conventional technology, the position of the pulse wave sensor relative to the wrist 112 was adjusted by inserting another member such as a spacer between the wrist 112 and the second arm 20, but with the pulse wave measuring device 100, the pulse wave sensor 31 can be positioned appropriately without inserting a spacer.

[0050] In the pulse wave measuring device 100, the movable part 40 is capable of swinging around a second swing axis (second axis) 41 that is provided on the second arm 20 and extends in the Y-axis direction. According to the pulse wave measuring device 100 having this configuration, swinging the movable part 40 around the second swing axis 41 makes it easy to fit the movable part 40 to the circumferential surface of the wrist 112.

[0051] Furthermore, in the pulse wave measuring device 100, the second oscillation shaft 41 is disposed on the opposite side of the radial artery 110 from the pulse wave sensor 31. With the pulse wave measuring device 100 configured as described above, the movable part 40 can be moved so as to approach the wrist 112 from the opposite side from the pulse wave sensor 31. In the pulse wave measuring device 100, the movable part 40 can be disposed so that the wrist 112 is sandwiched between the pulse wave sensor 31 and the movable part 40.

[0052] In addition, in the pulse wave measuring device 100, the movable part 40 is connected to the second oscillating shaft 41, and includes a push plate 42 that extends in a direction along a part of the circumference of the wrist 112 and can abut against a part of the circumference of the wrist 112, and an extension part 43 that is connected to the push plate 42 and extends from the push plate 42 in the opposite direction to the wrist 112 and in a direction that intersects with the second arm 20.

[0053] According to the pulse wave measuring device 100 having this configuration, the push plate 42 can be arranged along the circumferential surface (part of the periphery) of the wrist 112, and the push plate 42 can be fitted to the wrist 112. Furthermore, because the overhanging portion 43 overhangs in a direction intersecting with the second arm 20, the push plate 42 arranged inside the second arm 20 can be moved by operating the overhanging portion 43 that overhangs outside the second arm 20. The push plate 42 can be driven from outside the second arm 20 to fit the push plate 42 to the wrist 112.

[0054] The pulse wave measurement device 100 also includes a biasing member 50 that biases at least one of the first arm 10 and the second arm 20 in a direction that brings them closer to each other. With the pulse wave measurement device 100 configured as described above, the biasing member 50 biases at least one of the first arm 10 and the second arm 20, thereby bringing the first arm 10 and the second arm 20 closer to each other. Therefore, the biasing by the biasing member 50 allows the wrist 112 to be sandwiched between the first arm 10 and the second arm 20. The subject can wear the pulse wave measurement device 100 on their wrist 112 and measure their pulse wave by themselves.

[0055] Furthermore, in the pulse wave measuring device 100, the biasing member 50 is connected to the tip 43a of the overhanging portion 43, which is the end opposite the push plate 42. With the pulse wave measuring device 100 configured as described above, the biasing member 50 can be connected to the tip 43a of the overhanging portion 43 that overhangs the push plate 42, thereby biasing the push plate 42. Furthermore, in the pulse wave measuring device 100, the second arm 20 and the biasing member 50 can be connected via the overhanging portion 43 and the push plate 42. This allows the movable portion 40 and the second arm 20 to move in conjunction with each other. The pulse wave measuring device 100 does not require separate biasing members for biasing the movable portion 40 and biasing the second arm 20. This reduces the number of parts in the pulse wave measuring device 100 and reduces manufacturing costs.

[0056] Furthermore, in the pulse wave measuring device 100, the movable part 40 includes a pair of overhanging parts 43 spaced apart in the Y-axis direction, and a receiving part 45 extending in the Y-axis direction, connecting the tip parts 43 a of the pair of overhanging parts 43, and to which the biasing member 50 is connected. According to the pulse wave measuring device 100 having this configuration, the biasing member 50 can be connected to the second arm 20 via the receiving part 45 connecting the tip parts 43 a of the pair of overhanging parts 43. The force acting on the push plate 42 can be dispersed in the width direction of the push plate 42.

[0057] Furthermore, in the pulse wave measuring device 100, the receiving portion 45 can come into contact with the second arm 20, limiting the range of movement of the movable portion 40. With the pulse wave measuring device 100 configured as described above, the range of movement can be limited when the movable portion 40 is moved closer to the pulse wave sensor 31. For example, for a subject with a thin wrist 112, the range of movement of the movable portion 40 can be limited so as not to constrict the wrist 112.

[0058] Furthermore, the pulse wave measuring device 100 is a clip-type pulse wave measuring device, and the first arm 10 and the second arm 20 can be arranged opposite each other with the wrist 112 sandwiched therebetween, and curve along at least a portion of the wrist 112. In the pulse wave measuring device 100 having this configuration, the first arm 10 and the second arm 20 can be formed into a shape that curves along a portion of the circumferential surface of the wrist 112. Therefore, in the pulse wave measuring device 100, the first arm 10 and the second arm 20 can be easily brought into close contact with the wrist 112.

[0059] The pulse wave measuring device 100 also includes a first operating unit 13 connected to the base end 12 of the first arm 10, extending opposite the first arm 10, and swingable about a swing axis (first axis) 52, and a second operating unit 23 connected to the base end 22 of the second arm 20, extending opposite the second arm 20, and swingable about the swing axis 52. In the pulse wave measuring device 100 having this configuration, the first arm 10 and the second arm 20 can be opened and closed by operating the first operating unit 13 and the second operating unit 23. The subject can easily wear the pulse wave measuring device 100 on their wrist 112.

[0060] [First Modification] Next, a pulse wave measuring device 100 according to a first modification will be described. In the pulse wave measuring device 100 according to the above embodiment, the movable part 40 is moved by being biased using the biasing member 50, but the pulse wave measuring device 100 may be configured without the biasing member 50. The pulse wave measuring device 100 may also be provided with a drive unit for moving the movable part 40.

[0061] The pulse wave measuring device 100 according to the first modification may include a second biasing member that biases the movable part 40. The second biasing member is a biasing member different from the biasing member 50. The second biasing member is disposed between the push plate 42 and the second arm 20 and biases the push plate 42 toward the pulse wave sensor 31. The second biasing member may be, for example, a compression coil spring, a leaf spring, or a torsion spring.

[0062] The second biasing member is not limited to a spring member and may be another actuator. The actuator may be, for example, an electric motor. The pulse wave measuring device 100 may include, for example, an electric motor and a power transmission mechanism, and the driving force of the electric motor may be transmitted to the movable part 40 via the power transmission mechanism to drive the movable part 40. In addition, in the pulse wave measuring device 100, an air bag may be disposed between the push plate 42 and the second arm 20, and the air bag may be inflated using a pump to drive the movable part 40.

[0063] [Second Modification] Next, a pulse wave measurement device 100 according to a second modification will be described. In the pulse wave measurement device 100 according to the second modification, an anti-slip portion may be formed on the inner surface of the pressure plate 42. With this pulse wave measurement device 100, the frictional resistance between the wrist 112 and the pressure plate 42 can be increased, and rotational movement of the pulse wave measurement device 100 around the circumference of the wrist 112 can be reliably suppressed. With the pulse wave measurement device 100, displacement of the pulse wave sensor 31 can be suppressed.

[0064] The non-slip portion may have an uneven shape, for example. The pulse wave measuring device 100 may include a pressure plate 42 formed from a non-slip material. In the pulse wave measuring device 100, the first arm 10 and the second arm 20 may each have a non-slip portion formed on their inner surfaces.

[0065] [Third Modification] Next, a pulse wave measurement device 100 according to a third modification will be described. A weight portion with an adjustable center of gravity may be formed on the second arm 20. The center of gravity may be a position at which balance can be maintained to prevent the pulse wave measurement device 100 worn on the wrist 112 from rotating around the circumference of the wrist 112. For example, the weight portion may be formed by partially varying the thickness of the second arm 20. For example, the weight portion may be formed on the distal end 21 of the second arm 20. For example, the weight portion may be formed by changing the position and size of a rib formed on the second arm 20, thereby adjusting the center of gravity of the pulse wave measurement device 100. With this pulse wave measurement device 100, rotational movement of the pulse wave measurement device 100 when worn on the wrist 112 can be suppressed, and misalignment of the pulse wave sensor 31 can be suppressed.

[0066] [Fourth Modification] Next, a pulse wave measurement device 100 according to a fourth modification will be described. In the pulse wave measurement device 100, the width of the first arm 10 and the width of the second arm 20 may be different. For example, the width of the second arm 20 may be narrower than the width of the first arm 10. The position of the end in the width direction of the second arm 20 may be different from the position of the end in the width direction of the first arm 10, making it easier to bend the wrist 112. This makes it possible to avoid interfering with hand movement when the pulse wave measurement device 100 is worn.

[0067] Furthermore, in the pulse wave measurement device 100, the width of the second arm 20 may be different from the width of the second operation unit 23. The width of the second arm 20 may be narrower than the width of the second operation unit 23.

[0068] [Fifth Modification] Next, a pulse wave measurement device 100 according to a fifth modification will be described. The pulse wave sensor mounting unit 30 of the pulse wave measurement device 100 may have an attitude adjustment mechanism that can adjust the attitude of the pulse wave sensor 31. By changing the attitude of the pulse wave sensor 31, the orientation of the pulse wave sensor 31 with respect to the radial artery 110 can be adjusted.

[0069] [General Pulse Measurement Method] Generally, when measuring a pulse in a hospital or the like, the pulse is measured with the palm facing up and, for example, three fingers positioned along the radial artery 110. During this measurement, the wrist 112 is bent in a direction from the palm toward the back of the hand.

[0070] In the pulse wave measuring device 100 according to the fifth modification, the back of the hand is less likely to come into contact with the second arm 20, which can prevent the pulse wave sensor 31 from shifting in position. The pulse wave measuring device 100 can accurately measure the pulse wave.

[0071] [Pulse Wave Sensor 31] The pulse wave sensor 31 may include a housing, a strain gauge, and multiple strain gauges. The multiple strain gauges may be, for example, four strain gauges. The output signal of the pulse wave sensor 31 is generated based on the outputs of the multiple strain gauges. The multiple strain gauges are connected to form each arm of a bridge circuit, and the output signal of the pulse wave sensor 31 (a signal indicating the pulse wave) can be generated by the bridge circuit.

[0072] In the pulse wave sensor 31, the load portion of the strain gauge is placed near the subject's radial artery 110, and a load is applied to the load portion in accordance with the subject's pulse wave, causing the beam portion of the strain gauge to elastically deform. This changes the resistance value of the resistor of the strain gauge. The pulse wave sensor 31 can detect the pulse wave based on the change in resistance value of the resistor of the strain gauge that accompanies the deformation of the beam portion of the strain gauge. The pulse wave is detected as a periodic voltage change and output as a signal from the bridge circuit.

[0073] In the above example, the pulse wave sensor 31 has four strain gauges, and the output signal is generated by connecting the four strain gauges in a full bridge configuration. However, the pulse wave sensor 31 may have two strain gauges, and the output signal may be generated by connecting the two strain gauges in a half bridge configuration.

[0074] It should be noted that the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0075] In the above embodiment, the movable part 40 having the push plate 42 and the protruding part 43 is exemplified, but the movable part 40 may have other shapes. Furthermore, the movable part 40 is not limited to a swinging part, but may also be a part that moves linearly. The movable part 40 may also move linearly so as to approach the pulse wave sensor 31.

[0076] This patent application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 581,104, filed September 7, 2023, which is incorporated herein by reference in its entirety.

[0077] 100 Pulse wave measuring device, 10 First arm, 13 First operating unit, 20 Second arm, 23 Second operating unit, 30 Pulse wave sensor mounting unit, 31 Pulse wave sensor, 40 Movable unit, 41 Second swing axis (second axis), 42 Push plate, 43 Protruding portion, 43a Tip portion (tip portion of protruding portion), 45 Receiving portion, 50 Pressing member, 52 Swing axis (first axis), 60 Board mounting portion, 61 Wiring board (board), 110 Radial artery, 112 Wrist.

Claims

1. A pulse wave measuring device comprising: a first arm and a second arm capable of swinging relatively around a first axis extending in a first direction along the longitudinal direction of the radial artery; a pulse wave sensor mounted on the tip of the first arm; and a movable part connected to the second arm and capable of moving in a direction toward or away from the pulse wave sensor.

2. A pulse wave measuring device as claimed in claim 1, wherein the movable portion is provided on the second arm and is capable of swinging about a second axis extending in the first direction.

3. The pulse wave measuring device according to claim 2, wherein the second axis is disposed on the opposite side of the radial artery from the pulse wave sensor.

4. A pulse wave measuring device as described in claim 2 or 3, wherein the movable part comprises: a push plate connected to the second axis, extending in a direction along part of the circumference of the wrist and capable of abutting against part of the circumference of the wrist; and a protruding part connected to the push plate and extending from the push plate in the opposite direction to the wrist and in a direction intersecting the second arm.

5. A pulse wave measuring device as claimed in claim 4, wherein an anti-slip portion is formed on the surface of said pressure plate that is closest to said wrist.

6. A pulse wave measuring device according to any one of claims 1 to 5, further comprising a biasing member that biases at least one of the first arm and the second arm in a direction in which they approach each other.

7. A pulse wave measuring device as described in claim 4 or 5, further comprising a biasing member that biases at least one of the first arm and the second arm in a direction toward each other, the biasing member being connected to a tip end that is the end opposite the push plate of the protruding portion.

8. A pulse wave measuring device as described in claim 7, wherein the movable portion comprises: a pair of protruding portions spaced apart in the first direction; and a receiving portion extending in the first direction, connecting the tip ends of the pair of protruding portions, and to which the biasing member is connected.

9. The pulse wave measuring device according to claim 8, wherein the receiving portion is capable of abutting against the second arm and limits the range of movement of the movable portion.

10. A clip-type pulse wave measuring device as described in any one of claims 1 to 9, wherein the first arm and the second arm can be positioned opposite each other across the wrist and curve along at least a portion of the wrist.

11. A pulse wave measuring device as claimed in any one of claims 1 to 10, comprising: a first operating part connected to a base end of the first arm, extending on an opposite side to the first arm, and capable of swinging around the first axis; and a second operating part connected to a base end of the second arm, extending on an opposite side to the second arm, and capable of swinging around the first axis.

12. A pulse wave measuring device as claimed in any one of claims 1 to 11, wherein the first arm has a board mounting portion for mounting a board connected to the pulse wave sensor, and the second arm is formed with a weight portion whose center of gravity can be adjusted.

13. The pulse wave measuring device according to claim 12, wherein the weight portion is formed at the tip of the second arm.

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