Stacked photoplethysmography sensor

Abstract

This stacked photoplethysmography sensor can improve the accuracy of photoplethysmography by enhancing the positional relationship between a light-emitting element and a light-receiving element. The stacked photoplethysmography sensor of the present invention enhances the positional relationship between the light-emitting element and the light-receiving element so as to improve a light reception effect, thereby significantly improving the accuracy of blood flow measurement. The present invention can be processed in various forms by using a flexible film, such that accurate measurement results can be obtained while wearing discomfort to a user is minimized.

Description

Stacked photoplethysmography sensor

[0001] The present invention relates to a laminated photoplethysmography sensor, and more particularly, to a laminated photoplethysmography sensor that improves the accuracy of photoplethysmography by improving the positional relationship between a light-emitting element and a light-receiving element.

[0002] Photoplethysmography sensors are widely known as sensors that measure blood flow using light. Typically, photoplethysmography illuminates the skin or blood vessels and measures the intensity and distribution of the light reflected from the skin or blood vessels to determine blood flow.

[0003] Conventional photoplethysmography sensors typically have a single-layer, planar structure, with the light-emitting element and photodetector positioned on the same plane. However, this structure can result in measurement accuracy that varies depending on the installation location and target, and in some cases, can lead to inaccurate measurement results. Furthermore, crosstalk between the light-emitting element and photodetector can generate noise, lowering measurement accuracy.

[0004] Recently, with the miniaturization and thinning of hand health electronic devices or wearable electronic devices equipped with photoplethysmography sensors, photoplethysmography sensors are also required to be formed in a curved shape and miniaturized.

[0005] Accordingly, as the light-emitting and light-receiving portions of the photoplethysmography sensor are formed in a curved shape, the demand for a configuration and technology that can improve measurement accuracy is increasing.

[0006] The purpose of the present invention is to provide a laminated photoplethysmography sensor that improves the accuracy of photoplethysmography by improving the positional relationship between a light-emitting element and a light-receiving element.

[0007] In order to achieve the above purpose, a laminated photoplethysmography sensor according to the features of the present invention is provided.

[0008] photoreceptor;

[0009] A light-transmitting adhesive layer positioned on the upper portion of the light-receiving portion;

[0010] A light-emitting part laminated on top of the light-receiving part with the light-transmitting adhesive layer in between; and

[0011] Including a cover window located on the upper part of the light emitting part,

[0012] The above light receiving unit,

[0013] A light-receiving film formed of a flexible film;

[0014] An internal light-receiving element formed on the above light-receiving film; and

[0015] It includes an external light-receiving element formed on the above light-receiving film and positioned around the internal light-receiving element,

[0016] The above light emitting part is,

[0017] A light-emitting film formed of a flexible film; and

[0018] It includes a light emitting element formed on the light emitting film and positioned between the internal light receiving element and the external light receiving element when viewed from above the light emitting element.

[0019] The external light-receiving element is formed in a shape that surrounds the internal light-receiving element.

[0020] The internal light-receiving element and the external light-receiving element can be spaced apart at a certain interval.

[0021] The light-emitting element may be formed in a frame shape including a hollow portion extending forward and backward, the internal light-receiving element may be formed in a square shape and accommodated in the hollow portion of the light-emitting element, and the external light-receiving element may be formed in a frame shape including a hollow portion that accommodates the light-emitting element and the internal light-receiving element.

[0022] When viewed from the top of the light emitting portion, the internal light-receiving element and the light emitting element may be positioned apart from each other, and the light emitting element and the external light-receiving element may be positioned apart from each other.

[0023] The internal light-receiving element is formed in a square shape, the light-emitting portion is formed in a frame shape surrounding the periphery of the internal light-receiving element, the external light-receiving element is formed in a frame shape surrounding the periphery of the light-emitting portion, and the internal light-receiving element, the light-emitting portion, and the external light-receiving element can be spaced apart from each other by a specific distance.

[0024] The light-emitting portion may further include a partition made of a light-blocking material formed along both edges of the light-emitting element and extending vertically from the light-emitting portion film at a certain height.

[0025] By the above-described configuration, the laminated photoplethysmography sensor of the present invention improves the positional relationship between the light-emitting element and the light-receiving element, thereby improving the light-receiving effect and greatly improving the accuracy of blood flow measurement.

[0026] The present invention can be processed into various shapes using a flexible film, thereby minimizing discomfort to the user while obtaining accurate measurement results.

[0027] FIG. 1 is a drawing showing a cross-section of a laminated photoplethysmography sensor according to an embodiment of the present invention.

[0028] FIG. 2 is a cross-sectional view showing a partition formed along the edge of a light-emitting element according to an embodiment of the present invention.

[0029] FIG. 3 is a drawing showing the appearance of a light-emitting element and a light-receiving element when viewed from above the light-emitting part according to an embodiment of the present invention.

[0030] FIG. 4 is a drawing showing an example of the thickness of a light-receiving portion, a light-transmitting adhesive layer, and a light-emitting portion according to an embodiment of the present invention.

[0031] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Regardless of the drawing reference numerals, identical or similar components will be assigned the same reference numerals, and redundant descriptions thereof will be omitted. Furthermore, when describing embodiments disclosed in this specification, if a detailed description of a related known technology is judged to obscure the gist of the embodiments disclosed in this specification, the detailed description thereof will be omitted.

[0032] Terms that include ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely to distinguish one component from another.

[0033] Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0034] In this application, each step described may be performed regardless of the listed order, except in cases where a special causal relationship requires that the steps be performed in the listed order.

[0035] In this application, terms such as “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but should be understood not to exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0036]

[0037] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

[0038] FIG. 1 is a cross-sectional view of a laminated photoplethysmography sensor according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a partition formed along the edge of a light-emitting element according to an embodiment of the present invention.

[0039] A laminated photoplethysmography sensor (100) according to an embodiment of the present invention includes a light-receiving portion (110), a light-transmitting adhesive layer (114), a light-emitting portion (120), and a cover window (not shown).

[0040] Hereinafter, each component included in the laminated photoplethysmography sensor (100) of the present invention will be described in detail.

[0041] The light receiving unit (110) is located at the bottom of the laminated photoplethysmography sensor (100) of the present invention.

[0042] The light receiving unit (110) can measure the reflected light emitted by the light emitting unit (120) and reflected light reflected by the measurement unit and convert it into an electrical signal.

[0043] The light receiving unit (110) includes a light receiving element formed on a light receiving unit film (111).

[0044] The light-receiving film (111) may be formed of a flexible film. The light-receiving film (111) may be formed of a material that is transparent and can be deformed by an external force, such as, for example, a PET film.

[0045] The photodetector can be formed using elements such as organic photodiodes (OPDs). Technology has been developed for OPDs to detect objects even under strong light. OPDs are optical sensors that convert light energy into electrical energy to detect color and brightness.

[0046] Specifically, the light-receiving element can be formed by being deposited on the upper or lower surface of the light-receiving film (111). The light-receiving element can be formed of an organic element so that durability can be maintained even if the light-receiving film (111) is bent by an external force.

[0047] The light receiving element may include an internal light receiving element (112) and an external light receiving element (113).

[0048] The internal light-receiving element (112) may be formed to be surrounded by an external light-receiving element (113). Specifically, the internal light-receiving element (112) may be formed in a square or circular shape, and the external light-receiving element (113) may be formed to surround the internal light-receiving element (112).

[0049] The external light receiving element (113) may be formed in a form in which an opening is formed inside and the internal light receiving element (112) is accommodated in the opening. Specifically, the external light receiving element (113) may be formed in a frame shape.

[0050] The light-transmitting adhesive layer (114) is located on the upper portion of the light-receiving portion (110). The light-transmitting adhesive layer (114) primarily has a function of transmitting light, and may be, for example, OCA (Optical Clear Adhesive). The light emitted from the light-emitting portion (120) is irradiated to the measurement portion (skin, etc.) and then reflected, and the reflected light passes through the light-transmitting adhesive layer (114) and is irradiated to the light-receiving portion (110).

[0051] The thickness of the light-transmitting adhesive layer (114) is greater than the thickness of the light-receiving portion (110), but less than the combined thickness of the light-receiving portion (110) and the light-emitting portion (120). This may be a design consideration to improve the performance and efficiency of the sensor.

[0052] The thickness of the light-transmitting adhesive layer (114) is 40 μm, the thickness of the light-receiving portion (110) is 25 μm, and the thickness of the light-emitting portion (120) is 20 μm.

[0053] The light-emitting portion (120) is laminated on top of the light-receiving portion (110) with a light-transmitting adhesive layer (114) interposed therebetween. The light-emitting portion (120) is composed of a light-emitting portion film (121) formed of a flexible film and a light-emitting element (122) formed on the film. The light-emitting element (122) serves to emit light.

[0054] The light-emitting film (121) is flexible and can be bent by an external force, and can also form a free-form surface in a curved shape. The light-receiving film (111) can be formed of a material that is light-transmitting and can be deformed by an external force, such as, for example, a PET film. In particular, since the light-emitting film (121) is positioned on the upper portion of the light-receiving portion (110), it is necessary to have a light-transmittance level higher than a predetermined level.

[0055] The light-emitting element (122) is positioned between the internal light-receiving element (112) and the external light-receiving element (113) when viewed from the top of the light-emitting portion (120). In particular, the light-emitting element (122) can be formed in a frame shape and includes a hollow portion that penetrates forward and backward.

[0056] Some forms of the light-emitting portion (120) may include a partition wall (130) made of a light-shielding material, and the partition wall (130) extends vertically from the light-emitting portion film (121). In addition, the partition wall (130) may be partially inserted into a groove formed in the light-emitting portion film (121).

[0057] The partition wall (130) is formed along both edges of the light-emitting element (122), and can be formed by being inserted into the groove of the light-emitting film (121) and extending vertically from the light-emitting film (121) to a certain height.

[0058] The light-emitting element (122) can improve the light-receiving effect by minimizing light scattering due to the partition (130).

[0059] A cover window (not shown) is located above the light-emitting unit (120). The cover window serves to protect the light-emitting unit (120) and the light-receiving unit (110). In particular, it performs the function of protecting the elements inside the sensor from the external environment. The cover window may be combined with the light-emitting unit (120) via an adhesive film to strengthen the bonding with the light-emitting unit (120).

[0060] The stacked photoplethysmography sensor (100) can improve the accuracy of photoplethysmography measurement by improving the positional relationship between the light-emitting element (122) and the light-receiving element (112, 113) by positioning the light-emitting element (122) higher than the light-receiving element (112, 113).

[0061] The upper and lower surfaces of the cover window can be formed into a free-form shape.

[0062] Referring to Fig. 3, the positional relationship between the light-emitting element (122) and the light-receiving element (112, 113) will be described in detail.

[0063] FIG. 3 is a drawing showing the appearance of a light-emitting element and a light-receiving element when viewed from above the light-emitting part according to an embodiment of the present invention.

[0064] The laminated photoplethysmography sensor (100) includes a light-receiving portion (110) and a light-emitting portion (120). The light-receiving portion (110) and the light-emitting portion (120) are each formed using a flexible film as a support base. The flexible film is made of a light-transmitting material, such as PET, and can be bent or curved by an external force.

[0065] The light-receiving portion (110) and the light-emitting portion (120) are formed of a transparent organic insulator or an inorganic insulator, and the organic insulator may include polyimide (PI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), etc.

[0066] The light-receiving unit (110) includes a light-receiving unit film (111) formed of a flexible film. An internal light-receiving element (112) and an external light-receiving element (113) are formed on the light-receiving unit film (111). The internal light-receiving element (112) has, for example, a rectangular shape, and the external light-receiving element (113) is positioned to surround the internal light-receiving element (112).

[0067] The light-emitting part (120) also includes a light-emitting part film (121) formed of a flexible film, and a light-emitting element (122) is formed on this film. This light-emitting element (122) is located between the internal light-receiving element (112) and the external light-receiving element (113) when viewed from the top of the light-receiving part film (111).

[0068] The external light-receiving element (113) is formed in a form that surrounds the internal light-receiving element (112), and can be formed in the shape of a frame, specifically. This frame includes a hollow space in the center, and the internal light-receiving element (112) can be accommodated in this hollow space.

[0069] The light-emitting element (122) can be formed in a frame shape, and the central hollow portion accommodates the internal light-receiving element (112). The external light-receiving element (113) formed in this way includes a frame-shaped hollow portion that surrounds both the light-emitting element (122) and the internal light-receiving element (112).

[0070] The light-emitting element (122) and the internal light-receiving element (112) and the external light-receiving element (113) are positioned spaced apart from each other. The degree of separation between the light-emitting element (122) and the internal light-receiving element (112) and the external light-receiving element (113) can be adjusted at a certain level for optical interference and measurement accuracy of the sensor. Specifically, the degree of separation between the light-emitting element (122) and the internal light-receiving element (112) and the external light-receiving element (113) can be determined between 0.3 times and 0.6 times the width of the light-emitting element (122) and the internal light-receiving element (112) and the external light-receiving element (113).

[0071] The distance between the light-emitting element (122) and the internal light-receiving element (112) and the external light-receiving element (113) is 0.2 mm, the width of the light-emitting element (122) is 0.4 mm, the length of one side of the internal light-receiving element (112) is 2 mm, the length of one side of the light-emitting element (122) is 3.6 mm, and the length of one side of the external light-receiving element (113) is 4.7 mm.

[0072] The shape of the laminated photoplethysmography sensor (100) can be not only a simple flat shape, but also a free-form curved surface. An adhesive film can be positioned between the light-emitting unit (120) and the cover window. This adhesive film helps to increase the stability and durability of the sensor.

[0073] A support member (not shown) is positioned at the bottom of the light receiving unit (110). This support member has a curved upper surface and supports the light receiving unit (110). A cushion layer formed of a flexible material that functions as a cushion may be included between the light receiving unit (110) and the support member.

[0074]

[0075] Hereinafter, with reference to FIG. 4, the thickness relationship between the light-transmitting adhesive layer (114), the light-receiving portion (110), and the light-emitting portion (120) will be described.

[0076] FIG. 4 is a drawing showing an example of the thickness of a light-receiving portion, a light-transmitting adhesive layer, and a light-emitting portion according to an embodiment of the present invention.

[0077] The thickness of the light-transmitting adhesive layer (114) is formed to be greater than the thickness of the light-receiving portion (110), but smaller than the sum of the thicknesses of the light-receiving portion (110) and the light-emitting portion (120). Specifically, as illustrated in FIG. 4, the thickness of the light-receiving portion (110) may be 25 um, the thickness of the light-emitting portion (120) may be 20 um, and the thickness of the light-transmitting adhesive layer (114) may be formed to be 40 um.

[0078] The vertical separation between the light-receiving portion (110) and the light-emitting portion (120) is determined by the thickness of the light-transmitting adhesive layer (114). This vertical separation between the light-receiving portion (110) and the light-emitting portion (120) may be an important factor in determining the light-receiving effect of the light-receiving portion (110).

[0079] Therefore, the thickness of the light-transmitting adhesive layer (114) can be varied in various ways depending on the light-receiving effect of the light-receiving portion (110) described above.

[0080]

[0081] Hereinafter, embodiments of the laminated photoplethysmography sensor of the present invention have been described. The technical features disclosed in each embodiment of the present invention are not limited to that embodiment, and, unless mutually incompatible, the technical features disclosed in each embodiment may be combined and applied to other embodiments.

[0082] Therefore, although each embodiment focuses on its own technical features, each technical feature can be applied in combination with each other as long as they are not mutually incompatible.

[0083] The present invention is not limited to the above-described embodiments and the attached drawings, and various modifications and variations are possible within the scope of those skilled in the art. Therefore, the scope of the present invention should be defined not only by the claims of this specification but also by equivalents thereof.

Claims

1. Light receiving unit; A light-transmitting adhesive layer positioned on the upper portion of the light-receiving portion; A light-emitting part laminated on top of the light-receiving part with the light-transmitting adhesive layer in between; and Including a cover window located on the upper part of the light emitting part, The above light receiving unit, A light-receiving film formed of a flexible film; An internal light-receiving element formed on the above light-receiving film; and It includes an external light-receiving element formed on the above light-receiving film and positioned around the internal light-receiving element, The above light emitting part is, A light-emitting film formed of a flexible film; and A light emitting element formed on the light emitting film and positioned between the internal light receiving element and the external light receiving element when viewed from above the light emitting element. Stacked photoplethysmography sensor.

2. In paragraph 1, The above external light-receiving element is formed in a form that surrounds the above internal light-receiving element. Stacked photoplethysmography sensor.

3. In paragraph 2, The internal light-receiving element and the external light-receiving element are spaced apart at a constant interval. Stacked photoplethysmography sensor.

4. In paragraph 2, The above light-emitting element is formed in the shape of a frame including a hollow portion penetrating forward and backward, The above internal light-receiving element is formed in a square shape and is accommodated in the hollow portion of the light-emitting element, The above external light-receiving element is formed in the shape of a frame including a hollow portion that accommodates the light-emitting element and the internal light-receiving element. Stacked photoplethysmography sensor.

5. In paragraph 1, When viewed from the top of the above light emitting part, The above internal photodetector and the above light-emitting element are positioned apart from each other, The above light emitting element and the external light receiving element are positioned apart from each other. Stacked photoplethysmography sensor.

6. In paragraph 1, The above internal light-receiving element is formed in a square shape, The above light-emitting portion is formed in the shape of a frame surrounding the periphery of the internal light-receiving element, The external light-receiving element is formed in a frame shape surrounding the periphery of the light-emitting part, and the internal light-receiving element, the light-emitting part, and the external light-receiving element are spaced apart from each other at a specific interval. Stacked photoplethysmography sensor.

7. In paragraph 1, The light-emitting portion is formed along both edges of the light-emitting element and further includes a partition made of a light-blocking material that extends vertically at a certain height from the light-emitting portion film. Stacked photoplethysmography sensor.

8. In paragraph 7, The above-mentioned partition is formed by inserting at least a portion of it into a groove formed in the above-mentioned light-emitting film. Stacked photoplethysmography sensor.

9. In paragraph 1, The above light-receiving unit and the above light-emitting unit form a free-form surface in a curved shape. Stacked photoplethysmography sensor.

10. In paragraph 1, Further comprising an adhesive film positioned between the light emitting portion and the cover window. Stacked photoplethysmography sensor.

11. In paragraph 1, A support member having a curved upper surface and coupled to the lower portion of the light receiving member to support the light receiving member; and Further comprising a cushion layer formed of a flexible material and positioned between the light receiving portion and the support portion. Stacked photoplethysmography sensor.

12. In paragraph 1, The thickness of the above light-transmitting adhesive layer is formed to be larger than the thickness of the light-receiving portion and smaller than the sum of the thicknesses of the light-receiving portion and the light-emitting portion. Stacked photoplethysmography sensor.

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