Blood flow pulse wave sensor

Abstract

To obtain a blood flow pulse wave sensor that reduces strain on the earlobe and obtains accurate blood flow pulse waves. [Solution] The device consists of two clamping bodies, one end of which is a clamping portion for gripping a biological end, and the other end of which is connected by a shaft portion for the clamping portions to rotate toward the biological end; a pulse wave detection unit that optically detects pulse waves, which is placed on one or both of the clamping portions of the two clamping bodies; an elastic member that is placed on the other end of one clamping body and grips the biological end by the restoring force generated by contact and pressing with the other end edge of the other clamping body; and an ear hook portion connected to one or both ends of the clamping bodies.

Description

Technical Field

[0001] The present invention relates to a blood flow pulse wave sensor.

Background Art

[0002] As a method for detecting a pulse wave from a living body, a device that detects a pulse wave from a fingertip or an earlobe using a photoelectric conversion type reflective or transmissive optical sensor is generally used. A device for detecting a pulse wave from the earlobe is for holding and fixing it to the fingertip and earlobe by sandwiching with a spring pressure similar to that of a laundry scissors, so the clamping force is strong, blood flow is inhibited, and an accurate pulse wave signal may not be obtained. A blood flow pulse wave signal is a device for measuring important biological signals such as heart rate, SpO2 sensor, or PTT, PWS, etc. Also, when stimulating a living body as disclosed in Japanese Patent Laid-Open No. 5-337195, etc., a device has been proposed that detects the timing (diastolic phase) when blood flow is not inhibited and outputs an electrical stimulus at that timing, but accurate and stable detection of the pulse wave signal is important.

[0003] Japanese Patent Laid-Open No. 2016-195646 describes a configuration in which a rotary pad having a shape for the earlobe and a shape for the fingertip on the side facing the sensor surface (base) and the pressing side is rotated and switched according to the use site. Japanese Patent Publication No. 2020-513709 describes a deformable ear hole portion configured to be disposed in a human external auditory canal, and at least one outer ear electrode configured to be disposed on the ear outside the external auditory canal and detecting a bioelectric signal, and having a bendable arm to which pressure is applied so that the at least one outer ear electrode is pressed against the skin during use. A pulse wave detection sensor is described.

[0004] Japanese Patent Publication No. 2023-165220 describes a sensor unit formed by a pair of left and right ear hooks and a connecting part that connects the pair of ear hooks at the front, the connecting part being formed by a contact part that contacts the user's forehead and a pair of weight parts formed behind the pair of ear hooks, a bio-information sensor provided on the contact part and an environmental information sensor provided on one of the pair of weight parts. International Publication WO2019 / 043964 discloses an optical sensor having an ear hook portion that continuously contacts the back of the ear from the ear hook portion.

[0005] International Publication WO2020 / 100677 discloses a configuration comprising a main body configured to clamp the earlobe portion of the subject by a first attachment part and a second attachment part, and a measuring part that measures at least one of the subject's transcutaneous arterial oxygen saturation (SpO2) and blood flow rate. Japanese Patent Publication No. 2005-6906 discloses a configuration having a clip-type optical sensor that clamps onto the earlobe and a main body integrally formed with the ear hook portion. Japanese Utility Model Publication No. 7-27503 describes a clothespin-type pulse wave sensor that is designed to be worn over the ear, and it combines multiple light-emitting elements with a sensor that measures transmitted light on the earlobe. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2016-195646 [Patent Document 2] Special Publication No. 2020-513709 [Patent Document 3] Japanese Patent Publication No. 2023-165220 [Patent Document 4] International Publication No. WO2020 / 100677 [Patent Document 5] Japanese Patent Publication No. 2005-6909 [Patent Document 6] Japanese Patent Application Publication No. 5-337195 [Patent Document 7] Japanese Utility Model Publication No. 7-27503 [Overview of the project] [Problems that the invention aims to solve]

[0007] Prior art has disclosed sensors attached incidentally to the ear hook portion, utilizing the contact force with the skin generated when the sensor is worn over the ear, or combinations of clip-type or clothespin-type sensors with the ear hook portion. However, with clip-type and clothespin-type sensors, the weight of the sensor itself and the electrical leads must be held in place by the earlobe, which tends to result in a strong clamping force to prevent the sensor from falling off, and may also excessively compress blood vessels. Therefore, in order to perform sensing, it is necessary to ensure contact with the earlobe without overloading it.

[0008] Japanese Utility Model Publication No. 7-27503 discloses a combination of an ear hook and a clothespin-type ear sensor. However, as stated in the specification, the ear hook may be unnecessary, and the device relies on the clamping force of the clothespin type and is assumed to be maintained on the earlobe. Therefore, it does not necessarily consider measurement in a state that does not obstruct blood flow. Furthermore, since ear shape varies from person to person, when used for extended periods, such as during dialysis treatment, there is a need for a pulse wave sensor that has a configuration suited to the shape of the ear to minimize strain on the ear, and that can reliably detect blood flow pulse waves with minimal artifacts. With clothespin-type ear clips, the force with which they clamp onto the earlobe is determined by the internal spring, making adjustments complicated. [Means for solving the problem]

[0009] In view of the above, the present invention is The device consists of two clamping bodies, one end of which is a clamping portion for gripping a biological end, and the other end of which is connected by a shaft portion for rotating the clamping portion toward the biological end; a pulse wave detection unit for optically detecting pulse waves, which is positioned on one or both of the clamping portions of the two clamping bodies; an elastic member positioned at the other end of one clamping body, which grips the biological end by the restoring force generated by contact and pressing with the other end edge of the other clamping body; and an ear hook portion connected to one or both ends of the clamping bodies. The device is designed to be comfortable to wear without putting strain on the user's ear shape, and to grip the earlobe with appropriate clamping force without excessively compressing blood vessels, thereby enabling stable pulse wave detection. Furthermore, any configuration that allows force to be applied in the direction of clamping the clamping body by the restoring force of the elastic member is sufficient. Since this restoring force can be adjusted by the shape of the other end edge of the other clamping body, it is possible to make the device wearable for a long period of time without putting a burden on the earlobe, according to the shape and thickness of the earlobe, and to detect stable blood flow pulse waves.

[0010] In the present invention, the light source and light receiving unit are formed from laser light, infrared LEDs, near-infrared LEDs, etc., and the light receiving unit is formed from a light-receiving transistor, etc., and a single cylindrical, cubic, or other type of probe configuration may be formed. Furthermore, the light source and the light receiving unit may be housed adjacent to each other in one of the clamping bodies to receive reflected light, or they may be arranged facing each other to form a transmissive type. Furthermore, the present invention may also enable stable pulse wave detection by increasing the number of light sources, for example by arranging them around the light-receiving unit, to widen the area of ​​light illuminating living tissue such as the earlobe.

[0011] The elastic member in this invention is This device utilizes a cam-like mechanism that is attached to the other end of one clamping body, contacts the other end of the other clamping body, and generates a restoring force due to the shape of the other end face of the other clamping body, applying this restoring force in a direction different from that direction, but in the direction of clamping the earlobe. Since the pressing force is adjusted based on the change in the shape of the end edge of the other end of the elastic member, and the earlobe is pinched with this adjusted pressing force, by changing the shape of the end edge and adjusting the pressing force, an appropriate clamping force can be exerted without applying a force that would overly deform the blood vessel. Also, since the ear-hanging portion supports the clamping body itself, an appropriate clamping force on the earlobe can be maintained and stable measurement can be performed. Further, by configuring the elastic member as a combination of a sphere represented by a ball plunger and a spring, it is more durable than an elastic member formed integrally with the clamping body, and stable resilient elasticity with a snap is obtained. Note that there may be cases where a plunger other than a ball with elasticity is used.

[0012] The ear-hanging portion formed of a rod-shaped body in the present invention has flexibility that can be bent by hand, and can freely form a shape corresponding to the size of the ear. Irreversibility means that once bent, it does not return to its original state and remains in the bent state, and restoring force means that when deformed by applying a force, a force that tries to return to its original state occurs when the force is released.

Advantages of the Invention

[0013] The present invention realizes a pulse wave sensor that can accurately detect a blood flow pulse wave without burden on the ear, where the ear-hanging portion is deformable according to the shape of the ear and forms an appropriate clamping force on the earlobe, and is suitable for dialysis treatment or continuously detecting biological signals for a long time. Also, by using a sensor unit with a light receiving portion formed at the center and a plurality of light sources arranged around it, stable detection of the blood flow pulse wave is enabled.

Brief Description of the Drawings

[0014] [Figure 1] It is a diagram showing one embodiment of the present invention. [Figure 2] It is a diagram for explaining one embodiment of the present invention. [Figure 3] It is a diagram for explaining one embodiment of the present invention. [Figure 4]This is a diagram illustrating one embodiment of the present invention. [Figure 5] This is a diagram illustrating the operation of one embodiment of the present invention. [Figure 6] This figure shows the shape of an embodiment of the present invention. [Figure 7] This is a perspective view showing each component of another embodiment of the present invention separated. [Figure 8] This is a diagram illustrating another embodiment of the present invention. [Figure 9] This is a diagram illustrating another embodiment of the present invention. [Figure 10] This is a diagram illustrating the operation of an embodiment of the present invention. [Figure 11] This figure shows the shape of an embodiment of the present invention. [Figure 12] This figure shows an example of a pulse wave detection unit according to the present invention. [Modes for carrying out the invention]

[0015] The present invention comprises two clamping bodies, one end of which is a clamping portion for gripping a biological end, and the other end of which is connected by a shaft portion for allowing the clamping portion to rotate toward the biological end; a pulse wave detection unit for optically detecting pulse waves, which is positioned on one or both of the clamping portions of the two clamping bodies; an elastic member positioned at the other end of one clamping body, which grips the biological end by the restoring force generated by contact and pressing with the other end edge of the other clamping body; and an ear hook portion connected to one or both ends of the clamping bodies. The ear hook is adjustable to fit the shape of the ear, and when worn on the ear, it clamps the ear with moderate force, allowing for stable pulse wave measurement. This reduces the burden on the patient, and it has been shown to be clinically used as an ear sensor for long-term pulse wave measurement. It is also suitable for use as an ear sensor for pulse wave monitoring during sports training. Furthermore, because it is almost entirely composed of the clamping portion, it allows for the creation of inconspicuous, small, and compact ear sensors, making it suitable for use in wearable biomedical measuring devices, electrical stimulation devices, and the like. Furthermore, by incorporating a wireless transmitter into the ear hook, a cordless pulse wave sensor becomes possible. [Examples]

[0016] Next, an embodiment of the present invention will be described with reference to Figure 1. Figure 1(a) is a perspective view of the embodiment, and Figure 1(b) is a perspective view of (a) when it has been separated into its individual parts. Reference numeral 10 denotes the clamping body A, which is made of plastic, resin material such as ABS, PC, or POM. In the direction of clamping the earlobe, the clamping body A10 has a concave housing portion 10a with a protruding center to accommodate the sensor unit 14. The sensor unit 14 and the ring portion 15a are housed in the clamping body A10 with the ring portion 15a facing downwards in the figure. The housing portion 10a has a gap that is open to the outside, and guide portions 10b are formed on both sides of the gap to guide the electrical lead wires 16 extending from the sensor unit 14 and the ear hook member 15 extending from the ring portion 15a to the outside.

[0017] In the portion of the clamping body A10 located below the earlobe, two shaft support fixing portions 10c are integrally molded on both sides of the clamping body A10 and are formed approximately perpendicular to the clamping surface, sandwiching both sides of the shaft penetration portion 11b of the clamping body B11. The electrical lead wires 16 that transmit the output of the sensor unit 14 to the outside are bundled with the ear-hook member 15, pass through the guide portion 10b, and are then covered by the cover member 17. The tip surrounding portion 17a of the cover member 17 further covers and fixes the guide portion 10b as well. Only the electrical lead wires 16 extend from the rear end portion 17b of the cover member 17, and the ear hook portion 15 is housed inside the cover member 17. 11 is clamping body B, which is made of the same material as clamping body A10, and together with clamping body A10 is the part that clamps the earlobe. The clamping surface 11a is curved so that it is thicker at the top of the earlobe and becomes thinner towards the bottom in order to press against the earlobe according to its shape.

[0018] Below the portion of the clamping body B11 that clamps the earlobe, a shaft penetration portion 11b is formed, which has a through hole with a diameter sufficient to pass through and fix the shaft portion in order to rotatably connect with the clamping body A10. The shaft penetration portion 11b is positioned so as to be sandwiched between two shaft support fixing portions 10c. In this state, the shaft portion 12 penetrates the shaft penetration portion 11b in a fixed manner, and the end of the shaft portion 12 is further fixed so as to be rotatable between the two shaft support fixing portions 10c, forming a state in which the clamping body A10 and the clamping body B11 can rotate around the shaft portion 12 in a direction in which they overlap.

[0019] The bottom surface 11c of the shaft penetration portion of the clamping body B11 is positioned such that when the clamping body A10 and the clamping body B11 overlap, some or all of its surfaces come into contact with the elastic member 13. The bottom surface 11c of the shaft penetration portion is connected to the surface opposite to the clamping surface 11a, for example, via an acute-angled corner 11d. 12 is the shaft portion, which is formed from a rigid metal rod. Element 13 is an elastic member, integrally formed from the same material as the clamping body A10, and is a plate-like body with an elastic structure. Alternatively, it may be fastened to the clamping body A10 as a separate part by adhesive, welding, screws, etc. The separate fastening part may be made of a different material to adjust the clamping force. 14 is a sensor unit, in which a light output section and a light receiving section are housed together in a cylindrical case so that they are exposed on the side that contacts the earlobe. The optical output unit consists of, for example, a photodiode that outputs near-infrared light, visible light, infrared light, or laser light, or the end of an optical fiber connected to a photodiode that outputs laser light, and the light receiving unit is configured to receive, for example, laser light output from the optical output unit that has been reflected or transmitted through the earlobe.

[0020] 15 is an ear hook component, made of metal such as pure aluminum, aluminum alloy, or copper alloy, or of plastic with shape-retaining properties, with one end formed as a ring portion 15a and extending in a rod shape from one end to the other. The radius of the hollow portion of the ring portion 15a is sized to allow it to pass through the projection of the guide body 10b. Note that since the purpose of the ring portion 15a is to prevent it from coming off, it does not need to be a ring shape, and only needs to have a shape that prevents it from coming off. The ear-hook component 15 is preferably made of a material that is flexible and has sufficient rigidity to prevent deformation due to the weight of the sensor or accidental contact with the body or other objects. Element 16 is an electrical lead wire, consisting of a resin cover and a linear conductive member. One end is connected to the light output unit and the light receiving unit, and the other end is connected to the measuring device. 17 is a cover component, made of resin such as polyvinyl chloride, silicone rubber, or a heat-shrinkable tube made of fluoropolymer, and has a tip surrounding portion 17a formed at its tip to surround and fix the two guide portions 10b, and is intended to surround the ear hook member 15 and the electrical lead wire 16 that have passed through the guide portions 10b to form a single cord. The rear end portion 17b of the cover member 17 extends to at least as far as surrounding the entire ear hook member 15. Figure 2 is a perspective view showing the clamping bodies A10 and B11 in Figure 1(a) in a closed state. Figure 3 shows the ear hook portion curved and worn over the ear. (a) shows the clamping body A and clamping body B11 in a closed state, and (b) shows the clamping body B11 open perpendicular to clamping body A10.

[0021] Next, the action of clamping the earlobe in the embodiment shown in Figure 1 will be explained in detail using the diagram. Figure 5 shows the cross-sectional view indicated by x-x' in Figure 3 for each operation. Figure 5(a) shows the clamping bodies A10 and B11 in a closed state, with the elastic member 13 supporting or pressing the bottom surface 11c of the axial penetration portion of the clamping body B11 in a position where the clamping body B11 does not rotate. During use, the clamping body B11 is rotated around the shaft portion 12 to open it, as shown in Figure 5(b). At that time, the bottom surface 11c of the shaft penetration portion deforms as it presses the elastic member 13 downwards, generating a restoring force.

[0022] Furthermore, as shown in Figure 5(c), when the clamping body B11 is fully opened, the pressure on the bottom surface 11c of the shaft penetration portion is released. As shown in Figure 5(d), after opening the clamping bodies A10 and B11 with your fingers, clamp the earlobe MT and release your fingers. The bottom surface 11c of the shaft penetration portion is pressed downwards against the elastic member 13, and the restoring force due to the deformation presses against the bottom surface 11c of the shaft penetration portion. Using the principle of leverage, the clamping surface 11a of the clamping body B is pressed towards the earlobe MT, centered on the shaft portion 12, and the earlobe MT is clamped.

[0023] Figure 4 shows the state in which clamping bodies A10 and B11 are clamping the earlobe. At this time, the ear-hook member 15 and the cover member, which houses the electrical lead wires 16, are bent to conform to the shape of the base of the ear and are fixed to the ear in a manner that rests on the ear. The electrical lead wires 16 extend toward the face and are connected to the measuring device. Furthermore, by equipping the system with a wireless data transmission unit instead of a measuring device, it is possible to eliminate the need for electrical lead wires 16.

[0024] Figure 6 shows the overall configuration for clamping and supporting the earlobe in this embodiment. Figure 6(a) is a left side view, (b) is a rear view, (c) is a right side view, (d) is a front view, (e) is a top view, and (f) is a bottom view. The ear hooks are shown as rods, indicating their state before use. When attaching the ear hooks to the ears, they can be bent by hand to fit the shape of the ear.

[0025] Next, a second embodiment of the present invention will be described using Figures 7 to 11. In Figure 7, Reference numeral 20 denotes the clamping body A, which is made of the same material as the clamping body A in the embodiment shown in Figure 1. In the direction of clamping the earlobe, the clamping body A20 has a concave housing portion 20a with a central projection to accommodate the sensor unit 24. The sensor unit 24 and the ring portion 25a are housed in the clamping body A20 with the ring portion 25a facing downwards. The housing portion 20a has a guide groove portion 20b formed such that a recessed portion that is open to the outside protrudes. The guide groove portion 20b is formed to guide the electrical lead wires 26 extending from the sensor unit 24 and the ear hook member 25 extending from the ring portion 25a to the outside.

[0026] In the portion of the clamping body A20 located below the earlobe, two shaft support fixing portions 20c are formed integrally with the clamping body A20 and are oriented approximately perpendicular to the clamping surface, so as to be able to clamp both end faces of the shaft penetration portion 21b of the clamping body B21. Between the two shaft support fixing portions 20c, there is a housing opening 20d for accommodating the ball plunger housing 233. The electrical lead wires 26 that transmit the output of the sensor unit 24 to the outside are bundled with the ear-hook member 25 and then covered by the cover member 27 after passing through the guide groove 20b. The surrounding portion 27a at the tip of the cover member 27 is fitted so as to cover the guide groove portion 20b.

[0027] Only the electrical lead wires 26 extend from the rear end portion 27b of the cover member 27, and the ear hook portion 25 is housed inside the cover member 27. 21 is clamping body B, which is made of the same material as clamping body A20, and together with clamping body A20 is the part that clamps the earlobe. The clamping surface 21a is curved so that it is thicker at the top of the earlobe and becomes thinner towards the bottom, so as to conform to the shape of the earlobe without any difficulty. 21a is the clamping surface, which is the surface used to clamp the earlobe.

[0028] 21b is a shaft penetration portion, the part through which the shaft portion 22 penetrates the side surface, the part sandwiched between the two shaft support fixing portions 20c, and is formed with a width smaller than the width of the clamping surface of the clamping body B21. 21c shows the bottom surface of clamping body B21 and a portion of the edge at the other end of clamping body B21. The base surface 21c is formed in a flat shape.

[0029] 21d is a corner portion, which is the boundary between the bottom surface 21c and the clamping side surface of the shaft penetration portion 21b, and represents a part of the edge of the other end of the clamping body B21. 22 is the shaft portion, which is molded from the same material as the shaft portion 12 and is formed as a rod-shaped body. The shaft portion 22 is rotatably fixed at both ends by shaft support fixing portions 20c. Clamping bodies A20 and B21 rotate in directions that overlap each other.

[0030] Reference numeral 23 denotes a ball plunger body, which is a cylindrical ball plunger housing 233 having an open opening at the top, as shown in Figure 10(a). Inside it are a coil spring 232 and a sphere 231. The sphere 231 is fixed in the open opening of the ball plunger housing 233 by narrowing the diameter of the opening so that it does not fly out to the outside, and is slidable inside. When the sphere 231 slides, it pressurizes the coil spring 232 in the axial direction of the long cylindrical body inside, thereby forming a restoring force. The sphere of the ball plunger body 23 is positioned so as to be in contact with the surface of the shaft and end of the clamping body B21 under some pressure, with the clamping body A20 and clamping body B21 overlapping. 24 is a sensor unit, in which a pair of light output and light receiving sections are housed in a cylindrical case, with the side that contacts the earlobe being exposed.

[0031] Figure 10(d) shows a cross-section of the sensor unit 24 when it is attached. 241 is the light output section, such as an LED or photodiode, and 242 is the light receiving section, which is composed of a light-receiving optical semiconductor. The sensor unit 24 is shown as a reflective type, but a transmissive type may be formed by arranging the light-emitting element on clamping body A20 and the light-receiving element on clamping body B21, or vice versa. The optical output unit 240 consists of, for example, a photodiode that outputs near-infrared light, visible light, infrared light, or laser light, or the end of an optical fiber connected to a photodiode that outputs laser light, and the light receiving unit 241 receives the laser light output from the optical output unit that has been reflected or transmitted through the earlobe.

[0032] 25 is an ear hook component, molded from the same material as the ear hook component 15, with one end formed as a ring portion 25a, and extending from one end to the other in a rod shape. The radius of the hollow portion of the ring portion 15a is sized to allow it to pass through the projection of the guide portion 10b. The ear hook member 25, like the ear hook member 15, is preferably made of a material that is flexible and rigid enough not to deform due to the weight of the sensor or accidental contact with the body or other objects. 26 is an electrical lead wire, a combination of a resin cover and a linear conductive member, with one end connected to the light output unit and the light receiving unit, and the other end connected to the measuring device. 27 is a cover member molded from the same material as cover member 17, and has a surrounding portion 27a formed at its tip to surround and fix the guide groove portion 20b, and is intended to surround the ear hook member 25 and the electrical lead wire 26 that have passed through the guide groove portion 20b to form a single cord. The rear end portion 27b of the cover member 27 extends to at least as far as surrounding the entire ear hook member 25.

[0033] Figure 8(a) is a perspective view showing the combined configuration of each element shown in Figure 7, with the clamping body B21 open perpendicularly to the clamping body A20, and Figure 8(b) shows the clamping body B and the clamping body A20 superimposed on each other. Figure 9 shows the ear hook portion curved and placed over the ear. (a) shows the clamping body A and clamping body B21 in a closed state, and (b) shows the clamping body B21 open perpendicular to clamping body A20.

[0034] The operation of the embodiment shown in Figure 7 will be explained using Figure 10. Figure 10 shows the y-y' cross-section of Figure 9. Figure 10(a) shows the state in which clamping bodies A20 and B21 are superimposed, and the sphere 231 inside the ball plunger body 23 is pressurizing the axial penetration portion 21b of clamping body B21 with a predetermined pressure. This predetermined pressure creates a clamping force between the clamping body A20 and the earlobe clamping surface 21a of the clamping body B21, centered on the shaft portion 22 of the clamping body B21, preventing the clamping body B21 from easily opening outward relative to the clamping body A20.

[0035] Next, the clamping body B21 is manually opened outwards. The clamping body B21 rotates around the shaft portion 22, and as it rotates, the end edge portion of the clamping body B21 that contacts the sphere 231 changes from the surface of the shaft penetration portion 21b, through the corner portion 21d, to the bottom surface 21c. As a result, the pressing force changes with each contact between the part and the sphere 231, and this pressing force is maintained as the restoring force of the coil spring 232. Figure 10(b) shows the state in which the corner portion 21d of the clamping body B21 is pressing against the sphere 231, and the clamping body B21 rotates to open to the state shown in Figure 10(c).

[0036] When clamping the earlobe MT, the clamping surface 21a of the clamping body B21 is rotated away from the clamping body A20, and the earlobe is clamped. As shown in Figure 10(d), when the earlobe is clamped between the clamping body A20 and the clamping body B21, the restoring force of the spring 232 presses against the corner 21d of the clamping body B21 while the sphere 231 of the ball plunger body 23 is pressed against this corner 21d. With the shaft portion 22 as the center, the cam mechanism presses and clamps the earlobe MT between the clamping surface 21a and the sensor surface 24 of the clamping body A20. In this way, the elasticity of the ball plunger body 23 does not put stress on the joint surface between the plate-like body 13 and the clamping body A10 shown in Figure 1, and a stable clamping force can be formed.

[0037] Figure 10(d) shows a cross-sectional view when the sensor unit 24 is attached to the clamping body A. The sensor unit 24 is formed in a reflective manner. 241 is a light-emitting element, formed from a laser light source or an LED, and 242 is formed from a phototransistor for receiving light. When the light-emitting element 241 is a laser light source, an external laser light source is installed, and laser light is propagated from it via an optical fiber. In such cases, the end face of the optical fiber may be installed. The sensor unit 24 is shown as a reflective type, but is not limited to this and may be a transmissive type. In the case of a transmissive type, for example, the light source may be installed on the clamping body A20 and the light receiving unit may be installed on the clamping body B21 (the reverse installation is also possible).

[0038] Figure 11 shows the overall configuration for clamping and supporting the earlobe in this embodiment. Figure 11 is an overall configuration diagram showing the clamping bodies A20 and B21, as shown in Figure 10(c), in an open state. Figure 11(a) is a left side view, (b) is a rear view, (c) is a right side view, (d) is a front view, (e) is a top view, and (f) is a bottom view. The ear hooks are shown as rods, representing their state before use. When wearing them, they are bent by hand to fit over the ears.

[0039] Figure 12 shows the configuration of a sensor unit consisting of multiple light-emitting elements and one photodetector. Figure 1 shows an embodiment in which the light-emitting part and light-receiving part of the sensor unit 14 shown in Figure 1 and the sensor unit 24 shown in Figure 8 are each formed with one unit. However, Figure 12 shows an example of a sensor unit that performs stable pulse wave detection by widening the range of the light irradiation space and widening the range in which the reflected light reaches the light-receiving part.

[0040] Figure 12 is almost the same size and type as the sensor unit 14 in Figure 1, but with multiple light-emitting elements arranged around the circumference and a light-receiving element in the center. Figure 12(a) shows the electrical circuit board housed within the sensor unit, and Figure 12(b) shows the surface cover of the sensor unit. In Figure 12, 1200 is a surface cover that covers the substrate 1201 and is for contact with the earlobe surface, and is made of resin or plastic to prevent sweat from entering. 1201 is the substrate, which is made of an electrical circuit material such as glass epoxy resin. 1202 is a light-emitting device that emits infrared, near-infrared, red, and white light, and is chip-shaped. These are identical chips, designated as 1202a, 1202b, 1202c, and 1202d.

[0041] 1203 is a light receiver, used to convert the received light signal into an electrical signal, such as a phototransistor. 1204 is a conductive path A, formed from a conductive printed pattern for the substrate, and is connected to the ground terminals of the respective light emitters 1202a to 1202d and the photodetector 1203. 1205 is conductive path B, which is formed with a conductive printed pattern for the substrate similar to conductive path A, and is connected to, for example, the power terminals of each light-emitting element 1202a to 1202d. Terminal 1206 is a conductive terminal for light emission, terminal 1207 is a conductive terminal for light reception, and terminal 1208 is a ground (-) terminal, all of which are formed with a conductive printed pattern for the substrate similar to conductive path A1204. For example, the device is configured to emit light by providing an electrical output between the light-emitting conductive terminal 1206 and the ground (-) terminal, and to extract the reflected light signal between the light-receiving conductive terminal 1207 and the ground (-) terminal.

[0042] 1209 is a cover for the light-emitting element, and is made of plastic that is waterproof while being transparent enough to maintain the amount of light emitted. 1209a is provided for each light-emitting element 1202a, 1209b for 1202b, 1209c for 1202c, and 1209d for 1202d. 1210 is a cover for the light receiver and is made of the same light-transmitting material as the light-emitting cover 1209, but is made of a material that minimizes the attenuation of the amount of light received. The sensor unit shown in Figure 12 connects light-emitting elements electrically in parallel. Theoretically, it irradiates the living body with infrared light or the like at the same emission level, and the reflected light from the blood vessels is received by the photodetector 1203 located in the center. By increasing the direction of reflected light based on the emission of light from one light-emitting element to 360 degrees, stable light reception can be achieved, and blood flow pulse waves can be detected more accurately. [Industrial applicability]

[0043] This invention allows for the measurement of blood flow, pulse waves, and other parameters from the earlobe, and can be used as a biodetection sensor that provides appropriate clamping force and stable signal detection while minimizing strain on the ear even when worn for extended periods. [Explanation of symbols]

[0044] 10, 20 Clamping body A 11, 21 Clamping body B 12, 22 shaft section 13 Elastic members 14, 24 Sensor Units 15, 25 Ear hook components 16, 26 Electrical lead wires 17, 27 Cover components

Claims

1. A bio-pulse wave sensor comprising: two clamping bodies, one end of which is a clamping portion for gripping a biological end, and the other end of which is connected by a shaft portion for rotating the clamping portion toward the biological end; a pulse wave detection unit for optically detecting pulse waves, which is positioned on one or both of the clamping portions of the two clamping bodies; an elastic member positioned at the other end of one clamping body, which grips the biological end by the restoring force generated by contact and pressing with the other end edge of the other clamping body; and an ear hook portion connected to one or both ends of the clamping bodies.

2. The pulse wave sensor for biological use according to claim 1, wherein the elastic member is an elastic plate-like body integrally attached to the other end of one clamping body, and when rotated by the rotating part, the elastic plate-like body deforms under pressure in accordance with the shape of the other end edge of the other clamping body, and generates a restoring force based on said deformation.

3. The bio-pulse wave sensor according to claim 1, wherein the elastic member is a ball plunger, and when rotated by the rotating part, it is compressed and deformed by the shape of the other edge of the other clamping body that contacts the sphere of the ball plunger, and a restoring force is generated based on said deformation.

4. The biomedical pulse wave sensor according to claim 1, wherein the ear hook portion is a rod-shaped ear hook portion that is irreversibly deformable and flexible and connected to one end of clamping body A or clamping body B.

5. The bio-pulse wave sensor according to claim 1, wherein the clamping surface of one of the clamping bodies has a space that can accommodate the end of the earlobe when the earlobe is clamped.

6. The bio-pulse wave sensor according to claim 4, wherein the conductive cord connecting the light source and the light receiving part is bundled and fixed along the ear hook.

7. The pulse wave detection unit is formed by incorporating a light source and a light receiving unit into a single housing, as described in claim 1.

8. The pulse wave detection unit is formed by one light receiving unit and a plurality of light sources arranged to surround the light receiving unit, as described in claim 1.

9. The pulse wave detection unit is a bio-pulse wave sensor according to claim 8, wherein the plurality of light-emitting units are electrically connected in parallel.

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