CN219594569U - Photoplethysmograph sensor and wearable device - Google Patents

Abstract

The utility model discloses a photoplethysmograph sensor and a wearable device, wherein the photoplethysmograph sensor comprises a circuit board, light receiving pieces and a light emitting piece, the light receiving pieces and the light emitting piece are arranged on the same surface of the circuit board, the number of the light receiving pieces is at least four, at least four light receiving pieces are arranged around the light emitting piece, the distances between the light receiving pieces and the light emitting piece are equal, the at least four light receiving pieces comprise a first receiving piece, a second receiving piece, a third receiving piece and a fourth receiving piece, the first receiving piece and the third receiving piece are symmetrically arranged relative to the center of the light emitting piece, and the second receiving piece and the fourth receiving piece are symmetrically arranged relative to the center of the light emitting piece. The utility model can solve the problem of inaccurate human physiological parameters measured by the photoplethysmograph sensor due to low efficiency of the light receiving element for receiving the reflected light.

Description

Photoplethysmograph sensor and wearable device

Technical Field

The utility model belongs to the technical field of sensors, and particularly relates to a photoplethysmograph sensor and wearable equipment.

Background

PPG (Photo plethysmo graph ) is a sensor for detecting physiological parameters of a human body by using photoplethysmography, and is widely used in fields such as biomedicine. PPG sensor detection techniques are mainly two from a sensor layout perspective: one is a transmission type detection technology used in medical instruments, and the other is a reflection type detection technology used in the prior wearable products. The reflection type detection technology refers to that the light emitting element and the light receiving element are arranged on the same side, so that the light receiving element detects the light absorbed and emitted by the tissue part, and the physiological parameters of the human body are traced through the difference of the reflected light intensities.

In the related art, the PPG sensor includes a light emitting element and a plurality of light receiving elements, but the distance between each light receiving element and the light emitting element is not equal, and the arrangement position of each light receiving element relative to the light emitting element is not symmetrical, so that the distance between part of the light receiving elements and the light emitting element is larger, and the efficiency of the light receiving elements for receiving reflected light is not high, and the physiological parameters of the human body measured by the PPG sensor are inaccurate.

Disclosure of Invention

An object of the embodiments of the present utility model is to provide a photoplethysmograph sensor and a wearable device, which can solve the problem of inaccurate human physiological parameters measured by the photoplethysmograph sensor due to low efficiency of receiving reflected light by a light receiving element.

In order to solve the technical problems, the utility model is realized as follows:

in a first aspect, an embodiment of the present utility model provides a photoplethysmograph sensor, including a circuit board, light receiving elements and light emitting elements, where the light receiving elements and the light emitting elements are disposed on a same surface of the circuit board, the number of the light receiving elements is at least four, at least four light receiving elements are disposed around the light emitting elements, and distances between the light receiving elements and the light emitting elements are equal,

the at least four light receiving elements comprise a first receiving element, a second receiving element, a third receiving element and a fourth receiving element, wherein the first receiving element and the third receiving element are symmetrically arranged relative to the center of the light emitting element, and the second receiving element and the fourth receiving element are symmetrically arranged relative to the center of the light emitting element.

In a second aspect, an embodiment of the present utility model provides a wearable device, including a housing and a photoplethysmograph sensor as described above, where the photoplethysmograph sensor is disposed in the housing, the housing includes a transparent portion, the light receiving element and the light emitting element are disposed opposite to the transparent portion, and the light receiving element and the light emitting element are located between the circuit board and the transparent portion.

In the embodiment of the utility model, the first receiving element and the third receiving element are symmetrically arranged relative to the center of the light emitting element, the second receiving element and the fourth receiving element are symmetrically arranged relative to the center of the light emitting element, that is, the first receiving element and the third receiving element are positioned at two opposite sides of the light emitting element, and the second receiving element and the fourth receiving element are positioned at two opposite sides of the light emitting element, so that the light receiving elements can receive light reflected from tissue parts at different sides, the capacity of the light receiving elements for receiving light is increased, the distances between the light receiving elements and the light emitting element are equal, the problem that the distance between part of the light receiving elements and the light emitting element is larger is avoided, and the problem that the efficiency of the light receiving elements for receiving the light is not high is solved, and the problem that the physiological parameters of a human body measured by a photoplethysmograph sensor are inaccurate is solved. In addition, compared with the embodiment of arranging three or less light receiving pieces, the embodiment of the utility model is provided with at least four light receiving pieces, so that more light reflected from the tissue part can be received, and the accuracy of the human physiological parameters measured by the photoplethysmograph sensor can be improved.

Drawings

FIG. 1 is a schematic diagram of the structure of a photoplethysmograph sensor disclosed in an embodiment of this utility model;

FIG. 2 is a side view of a photoplethysmograph sensor disclosed in an embodiment of this utility model;

FIG. 3 is a bottom view of a photoplethysmograph sensor disclosed in an embodiment of this utility model;

fig. 4 is a cross-sectional view of a wearable device disclosed in an embodiment of the present utility model;

fig. 5 is a schematic structural diagram of a housing of a wearable device according to an embodiment of the present disclosure;

FIG. 6 is an assembly diagram between a wrist-off sensing FPC and a photoplethysmograph sensor according to an embodiment of the present utility model disclosed;

FIG. 7 is a schematic diagram of a Fresnel diaphragm according to an embodiment of the present utility model;

fig. 8 is a schematic structural diagram of a wearable device according to an embodiment of the present utility model.

Reference numerals illustrate:

100-circuit board, 200-light receiving part, 210-first receiving part, 220-second receiving part, 230-third receiving part, 240-fourth receiving part, 300-light emitting part, 400-processor, 500-housing, 510-transparent part, 600-wrist-off sensing FPC, 700-spacer, 800-Fresnel film, 810-second non-transparent area, 820-second transparent area, 801-fourth annular area, 802-third annular area.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

The terms first, second and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged, as appropriate, such that embodiments of the present utility model may be implemented in sequences other than those illustrated or described herein, and that the objects identified by "first," "second," etc. are generally of a type, and are not limited to the number of objects, such as the first object may be one or more. Furthermore, in the description and claims, "and/or" means at least one of the connected objects, and the character "/", generally means that the associated object is an "or" relationship.

The photoplethysmograph sensor and the wearable device provided by the embodiments of the present utility model are described in detail below with reference to the accompanying drawings.

As shown in fig. 1 to 3, an embodiment of the present utility model discloses a photoplethysmograph sensor including a circuit board 100, a light receiving member 200, and a light emitting member 300. Alternatively, the circuit board 100 may select a PCB board or an FPC board; the light receiving part 200 may select a PD (photo diode), an avalanche photodiode, or the like capable of converting an optical signal into an electrical signal, the light emitting part 300 may select an LED (Light Emitting Diode ), and the LED may be an LED device capable of emitting at least one of green light (G), red light (R), and infrared light (IR). In addition, the light emitting element 300 may be a component capable of emitting light, such as neon bulb.

The light receiving elements 200 and the light emitting elements 300 are disposed on the same surface of the circuit board 100, that is, the light receiving elements 200 and the light emitting elements 300 are disposed on any surface of the circuit board 100 along the thickness direction thereof, the number of the light receiving elements 200 is at least four, at least four light receiving elements 200 are disposed around the light emitting elements 300, and the distances between each light receiving element 200 and the light emitting element 300 are equal.

The at least four light receiving elements 200 include a first receiving element 210, a second receiving element 220, a third receiving element 230, and a fourth receiving element 240, the first receiving element 210 and the third receiving element 230 are symmetrically disposed with respect to the center of the light emitting element 300, and the second receiving element 220 and the fourth receiving element 240 are symmetrically disposed with respect to the center of the light emitting element 300, namely: the first receiving part 210 and the third receiving part 230 are arranged in a central symmetry with respect to the center of the light emitting part 300, and the second receiving part 220 and the fourth receiving part 240 are arranged in a central symmetry with respect to the center of the light emitting part 300. When the number of the light receiving members 200 is greater than or equal to five, the positions of the light receiving members 200 other than the first, second, third and fourth receiving members 210, 220, 230 and 240 may be arranged according to actual circumstances.

Specifically, in the embodiment of the present utility model, the first receiving element 210 and the third receiving element 230 are symmetrically disposed with respect to the center of the light emitting element 300, the second receiving element 220 and the fourth receiving element 240 are symmetrically disposed with respect to the center of the light emitting element 300, that is, the first receiving element 210 and the third receiving element 230 are located at two opposite sides of the light emitting element 300, and the second receiving element 220 and the fourth receiving element 240 are located at two opposite sides of the light emitting element 300, so that the light receiving element 200 can receive the light reflected from the tissue portion at different sides, the light receiving capability of the light receiving element 200 is increased, and the distances between the light receiving elements 200 and the light emitting element 300 are equal, so that the problem of larger distance between part of the light receiving element 200 and the light emitting element 300 is avoided, and the problem of low light receiving efficiency of the light receiving element 200 is solved, and the problem of inaccuracy of the physiological parameters of the human body measured by the photoplethysmography sensor is further solved. In addition, compared to the embodiment with three or less light receiving elements 200, at least four light receiving elements 200 are provided in the embodiment of the utility model, so that more light reflected from the tissue can be received, and the accuracy of the physiological parameters of the human body measured by the photoplethysmograph sensor can be improved.

In an alternative embodiment, the first receiving member 210, the second receiving member 220, the third receiving member 230 and the fourth receiving member 240 are arranged in a square shape, and the first receiving member 210, the second receiving member 220, the third receiving member 230 and the fourth receiving member 240 are respectively distributed on four vertexes of the first square where the four are located. In addition, the first receiving element 210, the second receiving element 220, the third receiving element 230 and the fourth receiving element 240 may be arranged in a rectangular shape, and compared with a square shape, the distance between each light receiving element 200 and the light emitting element 300 is larger when the square shape is arranged, so that the efficiency of receiving the reflected light by the light receiving element 200 is relatively lower. In addition, the first receiving member 210, the second receiving member 220, the third receiving member 230 and the fourth receiving member 240 are in a square distribution, i.e.: the first receiving element 210, the second receiving element 220, the third receiving element 230 and the fourth receiving element 240 are equidistantly and alternately distributed around the circumferential direction of the circumscribing circle of the first square, and the two adjacent receiving elements are respectively positioned at two endpoints of the quarter circumference of the circumscribing circle, so that each receiving element is uniformly distributed relative to the light emitting element 300, and further the photoplethysmography sensor can receive uniform light rays reflected by different sides of a tissue part, thereby improving the accuracy of human physiological parameters measured by the photoplethysmography sensor.

The light emitting member 300 in the embodiment of the present utility model includes a light emitting body, and the light emitting body may be a single component capable of emitting light, or a single body such as a light emitting chip. In an alternative embodiment, the illuminant 300 includes at least four illuminants, where the at least four illuminants are arranged in a square shape, and the at least four illuminants include a first illuminant, a second illuminant, a third illuminant and a fourth illuminant, and the illuminant 300 of the present embodiment includes at least 4 illuminants, so that the illuminant 300 emits more light toward the tissue portion, and thus the more light reflected from the tissue portion to the light receiving element 200, the higher the accuracy of the physiological parameters of the human body measured by the photoplethysmograph sensor of the present utility model.

The first illuminant, the second illuminant, the third illuminant and the fourth illuminant are respectively located on four vertices of a second square where the four illuminants are located, and a straight line where the first illuminant and the third illuminant are located coincides with a straight line where the first receiving element 210 and the third receiving element 230 are located, and a straight line where the second illuminant and the fourth illuminant are located coincides with a straight line where the second receiving element 220 and the fourth receiving element 240 are located, that is, the second square is located in the first square, one diagonal line of the first square is collinear with one diagonal line of the second square, and the other diagonal line of the first square is collinear with the other diagonal line of the second square. In addition to this arrangement, an angle may be formed between the line in which the first light emitter and the third light emitter are located and the line in which the first receiving element 210 and the third receiving element 230 are located, and an angle may be formed between the line in which the second light emitter and the fourth light emitter are located and the line in which the second receiving element 220 and the fourth receiving element 240 are located, where the angle may be 45 °, but this may be set so that the distance between each light emitter and each corresponding receiving element is larger. Therefore, the arrangement according to the previous embodiment of the present utility model can minimize the distance between each illuminant and each corresponding receiving element, thus increasing the ability of each receiving element to receive the emitted light, and thus improving the accuracy of the physiological parameters of the human body measured by the photoplethysmography sensor. In this embodiment, the center of the light emitting member 300 is the center point of the second square where the first light emitter, the second light emitter, the third light emitter and the fourth light emitter are located.

The photoplethysmograph sensor further includes a processor 400, where the processor 400 is electrically connected to the light receiving element 200 and the light emitting element 300, respectively, the processor 400 is disposed on the circuit board 100, where the processor 400 may be located on the same side as the light emitting element 300, but such arrangement may occupy a larger installation space of the circuit board 100, thereby resulting in an increase in the external dimension of the circuit board 100, and in an alternative embodiment, the circuit board 100 has a first surface and a second surface disposed opposite to each other, where the light receiving element 200 and the light emitting element 300 are disposed on the first surface, and where the processor 400 is disposed on the second surface, so that the installation space on the circuit board 100 can be saved, thereby achieving the purpose of reducing the external dimension of the circuit board 100, and where the processor 400 is disposed close to the light receiving element 200, thereby accelerating the reaction speed of the processor 400.

As shown in fig. 4 to 8, an embodiment of the present utility model further discloses a wearable device, which includes a housing 500 and the photoplethysmograph sensor according to any one of the above embodiments, where the photoplethysmograph sensor is disposed in the housing 500, so as to protect the photoplethysmograph sensor and reduce the risk of damage to the photoplethysmograph sensor, the housing 500 includes a transparent portion 510, the light receiving element 200 and the light emitting element 300 are disposed opposite to the transparent portion 510, and the light receiving element 200 and the light emitting element 300 are disposed between the circuit board 100 and the transparent portion 510, and light emitted from the light emitting element 300 irradiates a tissue portion through the transparent portion 510, and light reflected from the tissue portion reaches the light receiving element 200 through the transparent portion 510. The wearable device can enable a smart watch, a smart bracelet and the like, and the shell 500 can be used for bearing components such as a display screen and the like.

In an alternative embodiment, the circuit board 100 is connected to the housing 500, and a closed cavity is formed between the circuit board 100 and the transparent portion 510. When no airtight space is formed between the circuit board 100 and the transparent portion 510, stray light inside the housing 500 may interfere with the light emitting member 300 and the light receiving member 200, which may cause inaccuracy of the physiological parameters of the human body measured by the photoplethysmography sensor, but the airtight cavity formed between the circuit board 100 and the transparent portion 510 of the embodiment of the present utility model may isolate the stray light inside the housing 500, so as to avoid the interference of the stray light on the light emitting member 300 and the light receiving member 200. In addition, a step may be provided in the case 500, and the circuit board 100 may be placed on the step. Further, a positioning post may be disposed on the step, and a first positioning hole may be disposed on the circuit board 100, where the first positioning hole is in positioning fit with the positioning post. The circuit board 100 may also be attached to the housing 500 by bonding or the like.

The user wearing the wearable device loosely may result in inaccurate human physiological parameters measured by the photoplethysmograph sensor. Optionally, the wearable device further includes a wrist-off induction FPC600 electrically connected with the circuit board 100, optionally, an elastic sheet is arranged on the wrist-off induction FPC600, the wrist-off induction FPC600 is electrically connected with the circuit board 100 through the elastic sheet, the wrist-off induction FPC600 can detect the tightness degree of wearing the wearable device by a user, when the wearable device is loose to be worn by the user, the wrist-off induction FPC600 can transmit signals to the processor 400, and the processor 400 can send prompt signals to the user through a display screen of the wearable device. The wrist-removing induction FPC600 is of an annular structure, the wrist-removing induction FPC600 is adhered to one face, facing the transparent part 510, of the circuit board 100, one face, facing away from the circuit board 100, of the wrist-removing induction FPC600 is adhered to the shell 500, and a closed cavity is formed among the circuit board 100, the wrist-removing induction FPC600 and the transparent part 510, so that stray light in the shell 500 is isolated, and interference of the stray light on the light emitting part 300 and the light receiving part 200 is avoided. Further, on the basis that steps can be arranged, the wrist-removing induction FPC600 is provided with a second positioning hole, and the positioning column can pass through the first positioning hole and the second positioning hole to realize positioning matching of the positioning column and the first positioning hole and the second positioning hole.

Optionally, a temperature sensor is further disposed on the wrist-removing sensing FPC600, and the body temperature of the user is measured through the temperature sensor.

In an alternative embodiment, a spacer 700 is further disposed between the light emitting member 300 and the light receiving member 200, the spacer 700 is made of a light shielding material, and the spacer 700 has a ring-shaped structure. Specifically, if the spacer 700 is not provided, the light received by the light receiving member 200 includes the light reflected by the tissue portion, the light emitted by the light emitting member 300 and emitted to the light receiving member 200 through the housing 500, and the light directly irradiated to the light receiving member 200 by the light emitting member 300, which may cause inaccuracy of the physiological parameters of the human body measured by the photoplethysmograph sensor. The spacer 700 according to the embodiment of the present utility model can alleviate the interference of the light emitted from the light emitting element 300 and emitted to the light receiving element 200 through the housing 500 and the light directly irradiated to the light receiving element 200 from the light emitting element 300 to the light receiving element 200, so as to improve the accuracy of the physiological parameters of the human body measured by the photoplethysmograph sensor. Further, the height of the spacer 700 is greater than or equal to the height of the light emitting element 300, so that the spacer 700 can isolate the light emitted from the light emitting element 300, and the light emitted from the light emitting element 300 is prevented from interfering with the light receiving element 200.

In an alternative embodiment, the surface of the transparent portion 510 facing the circuit board 100 is further provided with a fresnel film 800, and the light receiving member 200 and the light emitting member 300 are disposed opposite to the fresnel film 800. The fresnel patch 800 focuses light emitted by the light emitting member 300 and reflected back from the tissue portions, which may allow the photoplethysmograph sensor to detect more accurate physiological parameters of the human body.

In an alternative embodiment, the transparent part 510 includes a first transparent region and a first non-transparent region, the first transparent region including a first annular region and a second annular region separated by the first non-transparent region, the first annular region being disposed opposite the light receiving member 200, the second annular region being disposed opposite the light emitting member 300; and/or the fresnel film sheet 800 includes a second non-transparent region 810 and a second transparent region 820, the second transparent region 820 including a third annular region 802 and a fourth annular region 801 separated by the second non-transparent region 810, the third annular region 802 being disposed opposite the light receiving element 200, the fourth annular region 801 being disposed opposite the light emitting element 300. Specifically, black ink may be applied to the transparent portion 510 and the fresnel film sheet 800, respectively, to form the first non-transparent region and the second non-transparent region 810, and a light shielding member may be attached to the transparent portion 510 and the fresnel film sheet 800 to form the first non-transparent region and the second non-transparent region 810. In the embodiment of the utility model, the light emitted by the light emitting element 300 reaches the tissue portion through the second annular region and/or the fourth annular region 801, the light reflected by the tissue portion reaches the light receiving element 200 through the first annular region and/or the third annular region 802, and the first non-transparent region and/or the second non-transparent region 810 can prevent external stray light from entering the housing 500, so as to prevent the external stray light from interfering with the light receiving element 200 and the light emitting element 300.

The embodiments of the present utility model have been described above with reference to the accompanying drawings, but the present utility model is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those having ordinary skill in the art without departing from the spirit of the present utility model and the scope of the claims, which are to be protected by the present utility model.

Claims (10)

1. A photoplethysmography sensor is characterized by comprising a circuit board (100), light receiving elements (200) and a light emitting element (300), wherein the light receiving elements (200) and the light emitting element (300) are arranged on the same surface of the circuit board (100), the number of the light receiving elements (200) is at least four, the at least four light receiving elements (200) are arranged around the light emitting element (300), the distances between the light receiving elements (200) and the light emitting element (300) are equal,

the at least four light receiving elements (200) comprise a first receiving element (210), a second receiving element (220), a third receiving element (230) and a fourth receiving element (240), wherein the first receiving element (210) and the third receiving element (230) are symmetrically arranged relative to the center of the light emitting element (300), and the second receiving element (220) and the fourth receiving element (240) are symmetrically arranged relative to the center of the light emitting element (300).

2. The photoplethysmograph sensor according to claim 1, characterized in that the first receiving element (210), the second receiving element (220), the third receiving element (230) and the fourth receiving element (240) are arranged in a square, the first receiving element (210), the second receiving element (220), the third receiving element (230) and the fourth receiving element (240) being distributed over four vertices of a first square where the four are located, respectively.

3. The photoplethysmograph sensor according to claim 2, characterized in that the light emitter (300) comprises at least four light emitters, which are arranged in a square, the at least four light emitters comprising a first light emitter, a second light emitter, a third light emitter and a fourth light emitter, which are located on four vertices of a second square where the four light emitters are located, respectively, and in that the straight lines where the first light emitter and the third light emitter are located coincide with the straight lines where the first receiving element (210) and the third receiving element (230), and in that the straight lines where the second light emitter and the fourth light emitter are located coincide with the straight lines where the second receiving element (220) and the fourth receiving element (240).

4. The photoplethysmograph sensor according to claim 1, characterized in that it further comprises a processor (400), which processor (400) is electrically connected to the light receiving element (200) and the light emitting element (300), respectively,

the circuit board (100) is provided with a first surface and a second surface which are arranged back to back, the light receiving part (200) and the light emitting part (300) are arranged on the first surface, the processor (400) is arranged on the second surface, and the processor (400) is arranged close to the light receiving part (200).

5. A wearable device, characterized by comprising a housing (500) and a photoplethysmograph sensor according to any one of claims 1-4, said photoplethysmograph sensor being provided within said housing (500), said housing (500) comprising a transparent portion (510), said light receiving element (200) and said light emitting element (300) being arranged opposite to said transparent portion (510), and said light receiving element (200) and said light emitting element (300) being located between said circuit board (100) and said transparent portion (510).

6. The wearable device according to claim 5, characterized in that the circuit board (100) is connected to the housing (500), a closed cavity being formed between the circuit board (100) and the transparent part (510).

7. The wearable device according to claim 6, further comprising a wrist-off induction FPC (600) electrically connected to the circuit board (100), wherein the wrist-off induction FPC (600) has a ring-shaped structure, the wrist-off induction FPC (600) is adhered to a surface of the circuit board (100) facing the transparent portion (510), a surface of the wrist-off induction FPC (600) facing away from the circuit board (100) is adhered to the housing (500), and the sealed cavity is formed among the circuit board (100), the wrist-off induction FPC (600) and the transparent portion (510).

8. The wearable device according to claim 5, characterized in that a spacer (700) is further provided between the light emitting element (300) and the light receiving element (200), the spacer (700) being made of a light shielding material, the spacer (700) having a ring-shaped structure.

9. The wearable device according to claim 5, wherein a fresnel film (800) is further provided on a surface of the transparent portion (510) facing the circuit board (100), and the light receiving member (200) and the light emitting member (300) are disposed opposite to the fresnel film (800).

10. The wearable device according to claim 9, characterized in that the transparent part (510) comprises a first transparent area and a first non-transparent area, the first transparent area comprising a first annular area and a second annular area separated by the first non-transparent area, the first annular area being arranged opposite the light receiving element (200), the second annular area being arranged opposite the light emitting element (300); and/or, the fresnel film sheet (800) comprises a second transparent region (820) and a second non-transparent region (810), the second transparent region (820) comprising a third annular region (802) and a fourth annular region (801) spaced apart by the second non-transparent region (810), the third annular region (802) being disposed opposite the light receiving element (200), the fourth annular region (801) being disposed opposite the light emitting element (300).