Electret inductor

Abstract

The invention relates to the technical field of electret inductors, and particularly discloses an electret inductor which comprises an isolating membrane layer, a first electret thin film layer arranged in the isolating membrane layer, a first conductive layer arranged in the first electret thin film layer, a second electret thin film layer arranged in the first conductive layer, and a second conductive layer arranged in the second electret thin film layer. A second conductive layer is arranged in the second electret thin film layer, a concave curved surface is formed on the first electret thin film layer, and a crossed supporting structure is arranged on the concave curved surface. The electret inductor with the crossed supporting structure can receive micro-vibration from the chest wall to the maximum extent, meanwhile, interference of external charges on the polarity of charges on the surface of the electret film can be reduced, and the electret inductor is more suitable for continuously monitoring breathing sound in a long range.

Description

Technical Field

[0001] The invention relates to the technical field of electret inductors, in particular to an electret inductor. Background Art

[0002] Breathing is the most basic life activity. Changes in lung breath sounds are an early response to abnormal respiratory patency and the earliest warning information in respiratory function rating. In critically ill and elderly patients, as well as in emergency rescue and elderly care environments, rapid assessment of respiratory status and long-term continuous warning monitoring are crucial diagnostic and treatment measures.

[0003] At present, most of the vibrating membranes used for respiratory sound monitoring use capacitor coils with a relatively hard substrate and inorganic piezoelectric materials. The devices are large and difficult to bend. They cannot adapt to the curve of the human chest and are not suitable for long-term wearable use. The flexible electret vibrating membrane is electrostatic. In addition to its flexibility and bendability, it also has the advantages of simple structure, light weight, easy production and free cutting. It has great potential in the application of long-term continuous respiratory sound monitoring.

[0004] For example, Chinese patent document CN110987248A discloses a flexible tactile sensor and a preparation method thereof, comprising a piezoelectric electret cable sensing unit and a piezoelectric film sensing unit that are conductively connected to each other, wherein the piezoelectric electret cable sensing unit comprises a core electrode, a piezoelectric electret layer, a shielding layer and a sheath protective layer that are coaxially connected in sequence from the inside to the outside, and the piezoelectric film sensing unit comprises a first electrode layer, a piezoelectric material layer and a second electrode layer that are longitudinally distributed and connected in sequence, the shielding layer is connected to the piezoelectric cable grounding lead, the first electrode layer is connected to the first electrode lead of the piezoelectric film, and the second electrode layer is connected to the second electrode lead of the piezoelectric film.

[0005] Although the current flexible electret vibrating membrane has shown good performance in terms of sensitivity, response frequency, etc., it has poor performance in signal acquisition stability and resistance to external charge interference, and cannot meet the requirements of long-term attached monitoring of respiratory sounds. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to disclose an electret sensor, a device for attaching respiratory sound monitoring, having an electret vibrating membrane with a cross-type support structure. This electret sensor can receive micro-vibrations from the chest wall to the maximum extent, and at the same time can reduce the interference of external charges on the surface charge polarity of the electret membrane, and is more suitable for long-term continuous monitoring of respiratory sounds.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] An electret inductor comprises an isolation film layer, a first electret film layer is arranged inside the isolation film layer, a first conductive layer is arranged inside the first electret film layer, a second electret film layer is arranged inside the first conductive layer, a second conductive layer is arranged inside the second electret film layer, a concave curved surface is formed on the first electret film layer, a cross-type supporting structure is arranged on the concave curved surface, so that the electret film has sufficient vibration gap;

[0009] As a preferred technical solution of the present invention, the first electret film layer, the second electret film layer, the first conductive layer and the second conductive layer are arranged inside the isolation film layer in a folded manner; the first conductive layer and the second conductive layer are both led out through wires as interfaces of the sensor;

[0010] As a preferred technical solution of the present invention, the first electret film layer includes an electret film layer arranged in upper and lower planes, and also includes a side electret film layer connected up and down on one side; the first electret film layer is recessed inwardly in an array to form a plurality of recessed curved surfaces, and a cross-type support structure is provided on the recessed curved surface; and a first conductive layer is provided along the inner wall of the first electret film layer;

[0011] As a preferred technical solution of the present invention, the second electret film layer includes an electret film layer arranged in upper and lower planes, and also includes a side electret film layer connected up and down on one side, and a second conductive layer is arranged along the inner wall of the second electret film layer;

[0012] As a preferred technical solution of the present invention, the cross-type support structure includes a plane figure on the first electret film layer, and a support point formed by extending the point in the plane figure to the inside of the first electret film layer, and connecting the vertex and the support point of the plane figure through an arc to form a cross support frame; the edge of the plane figure forms a depression toward the inside of the first electret film layer, and the depression converges on the cross support frame to form a cross-type support structure;

[0013] As a preferred technical solution of the present invention, the cross-type support structure is a cross-type support structure, and the length of the cross-type support structure is 1-2.5 mm and the width is 1-2.5 mm;

[0014] As a preferred technical solution of the present invention, the plane figure is a closed plane figure, and the closed plane figure is a circle, a polygon, a sector or an irregular figure;

[0015] As a preferred technical solution of the present invention, the side electret film layer is a curved electret film layer or a flat electret film layer;

[0016] As a preferred technical solution of the present invention, the material of the conductive layer is silver, aluminum or copper;

[0017] As a preferred technical solution of the present invention, the material of the electret film layer is poly(perfluoroethylene-propylene) copolymer.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) By setting up a cross-type support structure, there is enough vibration gap between the two layers of electret film, which enhances the charge density and improves the monitoring sensitivity; a large tension is generated, so that the electret film layer is firmly attached to the chest wall and is not easy to fall off;

[0020] (2) By folding the electret film layer and the conductive layer, the conductive layer is completely wrapped inside the electret film layer, which reduces the interference of external charges, enhances the induction of vibration, and further improves the sensitivity of monitoring;

[0021] (3) By adding an isolation film layer with a low Young's modulus to wrap the electret film layer and the conductive layer, the vibration conduction is not affected, the interference of external charges is further reduced, and the stability of the electret sensor is enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is the front view of the electret sensor;

[0023] Figure 2 It is a top view of the electret sensor;

[0024] Figure 3 It is a three-dimensional diagram of an electret sensor;

[0025] Figure 4 It is a raised three-dimensional image of a cross-shaped support structure;

[0026] Figure 5 It is a concave three-dimensional image of the cross-shaped support structure.

[0027] In the figure:

[0028] 1-first electret film layer; 2-second electret film layer; 3-first conductive layer;

[0029] 4-second conductive layer; 5-cross-type supporting structure; 6-isolation film layer; 7-conducting wire. DETAILED DESCRIPTION

[0030] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The present invention is provided with accompanying drawings, which are part of the disclosure of the present invention and are mainly used to illustrate embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in the field should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0032] The present invention is further described with reference to the accompanying drawings and specific embodiments:

[0033] See also Figures 1 to 5 The first electret film layer 1 includes an electret film layer arranged on two upper and lower planes, and also includes a side electret film layer connected up and down on one side; a unit array of a plurality of concave curved surfaces is arranged on the two planes of the first electret film layer 1, and the concave curved surfaces of the upper and lower plane layers are both concave toward the inside of the first electret film layer 1, and a cross-type support frame is arranged on the concave curved surface, and the intersection point of the cross-type structure of the concave curved surface is at the bottom vertex of the concave curved surface; the back side of the concave curved surface is the corresponding convex curved surface, and the concave and convex curved surfaces form a curved body, and the wall thickness of the curved body is the same as the wall thickness of other parts on the first electret film layer 1;

[0034] Figure 1 In the embodiment, a second electret film layer 2 is arranged between the upper and lower concave curved bodies of the first electret film layer 1. The second electret film layer 2 includes electret film layers arranged on upper and lower planes, and also includes a side electret film layer connected up and down on one side.

[0035] In the above description, the side electret film layer may be a curved electret film layer or a flat electret film layer.

[0036] Figure 1 In the embodiment, a first conductive layer 3 is arranged in a first electret film layer 1 along an inner wall of the first electret film layer 1, and a second conductive layer 4 is arranged in a second electret film layer 2 along an inner wall of the second electret film layer 2, wherein the second electret film layer 2 is inside the first conductive layer 3; both the first conductive layer 3 and the second conductive layer 4 are connected to an interface of the sensor through a wire 7; both the electret film layer and the conductive layer are folded, and the electret film layer wraps the conductive layer completely inside the film, thereby reducing interference from external charges and increasing induction of film vibration.

[0037] Figure 1 In the embodiment, an isolation film layer 6 is arranged outside the first electret film layer 1 to wrap and cover the first electret film layer 1, the second electret film layer 2, the first conductive layer 3, the second conductive layer 4, and the cross-type support structure 5, thereby playing a protective and isolating role.

[0038] Figure 1In the embodiment, the cross-type support structure 5 ensures that there is enough vibration gap between the two layers of electret film, while retaining a large tension plane to contact the chest wall, which is more suitable for contact-type sensing of micro-vibrations transmitted from the air flow in the trachea to the chest wall. The cross-type support structure 5 is 1-2.5 mm long and 1-2.5 mm wide, preferably 1.5 mm long and 1.5 mm wide; the protrusion height of the cross-type support structure 5 is 0.2-0.5 mm, preferably 0.3 mm; the cross-type support structure 5 is preferably 16 in a group.

[0039] Figure 2 is a top view of the electret sensor. Figure 2 In the figure, a plurality of circles are arranged in an array on the plane of the first electret film layer 1. Among them, four adjacent circles are tangent to each other, generating four tangent points at the upper, lower, left and right sides, and the four tangent arcs formed form a closed plane figure; the upper and lower tangent points and the left and right tangent points are connected to obtain two line segments, and the two line segments intersect to form an intersection point; the intersection point in this closed plane shape extends 0.2-0.5mm into the first electret film layer 1 to form a support point, preferably 0.3mm, and the left tangent point, the support point and the right tangent point are connected by an arc line to form a first arc line, and the upper tangent point, the support point and the lower tangent point are connected by an arc line to form a second arc line, and then a cross support frame is formed along the first arc line and the second arc line; a closed plane figure is formed on the first electret film layer 1, and a depression is formed inside the first electret film layer 1 with the edge of the closed plane figure, and the depression converges on the cross support frame to form a concave curved surface, that is, a cross-type support structure 5. The cross-type support structure 5 is preferably a cross-type support structure, the diameter of the circles in the first electret film layer 1 is 1-2.5 mm, the center spacing is 1-2.5 mm, preferably the diameter is 1.5 mm, and the center spacing is 1.5 mm.

[0040] Figure 2 In the figure, the closed plane figure on the plane of the first electret film layer 1 can be a circle, a polygon, a sector or an irregular figure; the point to be extended selected in the closed plane figure can be any point in the plane, preferably the center point of the plane figure; when the closed plane figure is a circle and a concave surface is formed, the two end points and the support points of the circle diameter are connected by arcs to form a cross support frame, wherein the selected diameters are 2 or more, preferably 2 diameters perpendicular to each other, to further form a cross support frame.

[0041] When the closed plane figure is a circle, after the cross support frame is formed, the edge of the closed plane figure is further recessed to form a concave curved surface, and the concave curved surface converges on the cross support frame to form a cross-shaped support structure.

[0042] The present invention illustrates the technical concept of the present invention through the above embodiments, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. For ordinary technicians in this field, relevant improvements to the present invention fall within the protection scope and disclosure scope of the present invention.

Claims

1. An electret inductor, characterized in that: The invention comprises an isolation film layer (6), wherein a first electret film layer (1) is provided inside the isolation film layer (6), a first conductive layer (3) is provided inside the first electret film layer (1), a second electret film layer (2) is provided inside the first conductive layer (3), a second conductive layer (4) is provided inside the second electret film layer (2), a concave curved surface is formed on the first electret film layer (1), and a cross-type support structure (5) is provided on the concave curved surface.

2. The electret inductor according to claim 1, characterized in that: The first electret film layer (1), the second electret film layer (2), the first conductive layer (3) and the second conductive layer (4) are all arranged inside the isolation film layer (6) in a folded manner; the first conductive layer (3) and the second conductive layer (4) are both led out through a wire (7) as an interface of the sensor.

3. The electret inductor according to claim 2, characterized in that: The first electret film layer (1) comprises an electret film layer arranged in upper and lower planes, and also comprises a side electret film layer connected up and down on one side; the first electret film layer (1) is recessed inwardly in an array to form a plurality of recessed curved surfaces, and a cross-type support structure (5) is formed on the recessed curved surfaces; and a first conductive layer (3) is arranged on the inner wall of the first electret film layer (1).

4. The electret inductor according to claim 2, characterized in that: The second electret film layer (2) comprises electret film layers arranged in upper and lower planes, and also comprises a side electret film layer connected up and down on one side, and a second conductive layer (4) is arranged on the inner wall of the second electret film layer (2).

5. The electret inductor according to claim 3, characterized in that: The cross-type support structure (5) comprises a plane figure on the first electret film layer (1), and support points formed by extending from points in the plane figure into the interior of the first electret film layer (1); a cross support frame is formed by connecting the vertices of the plane figure and the support points through arc lines; A depression is formed inside the first electret film layer (1) with the edge of the plane figure, and the depression converges toward the cross support frame to form a cross support structure (5).

6. The electret inductor according to claims 1-5, characterized in that: The cross-shaped support structure (5) is a cross-shaped support structure, and the length of the cross-shaped support structure is 1-2.5 mm, and the width is 1-2.5 mm.

7. The electret inductor according to claim 5, characterized in that: The plane figure is a closed plane figure, and the closed plane figure is a circle, a polygon, a sector or an irregular figure.

8. The electret inductor according to claim 4, characterized in that: The side electret film layer is a curved electret film layer or a flat electret film layer.

9. The electret inductor according to claim 1, characterized in that: The conductive layer is made of silver, aluminum or copper.

10. The electret inductor according to any one of claims 1 to 9, characterized in that: The material of the electret film layer is poly(perfluoroethylene-propylene) copolymer.

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