Noise-reducing stethoscope head and stethoscope

Abstract

The present invention relates to the technical field of heart and lung sound detection, and specifically to a noise-reducing stethoscope head and stethoscope, comprising a sound receiving component, a sound guide tube, and a vibration membrane. The sound receiving component is trumpet-shaped, the sound guide tube is a small end of the sound receiving component that protrudes outward, and the end face of the large end of the sound receiving component is circular. The noise-reducing stethoscope head also includes a noise-reducing ring, which is fixedly arranged on the end face of the large end of the sound receiving component, and the vibration membrane is fixedly arranged on the inner wall of the noise-reducing ring. The vibration membrane does not contact the sound receiving component, and the noise-reducing ring is a through annular cavity. The core concept of the present invention is to use the noise-reducing ring to reduce the noise transmitted from the skin and the environment to the vibration membrane, and has good application prospects in the field of heart and lung sound detection technology.

Description

Technical Field

[0001] The present invention relates to the technical field of heart and lung sound detection, and in particular to a noise-reducing stethoscope head and a stethoscope. Background Art

[0002] In 1816, French physician René Laennec used a rolled-up paper tube to connect the patient's chest to the doctor's ear to listen to heart and lung sounds, creating the world's first stethoscope. While this stethoscope could detect heart and lung sounds, it had several limitations in terms of sound reception and transmission. With technological advancements, research on stethoscopes and heart sound signals has made significant progress, and heart and lung sound acquisition technology and equipment have been continuously updated. Today, the stethoscope has become a common diagnostic tool for doctors.

[0003] Because heart and lung sounds are weak, low-frequency signals belonging to human physiological signals, they are easily interfered with by skin and environmental noise, making it difficult for doctors to make accurate diagnoses. Researchers often perform noise reduction processing on the electrical signals of heart and lung sounds to reduce the noise. For example, researchers have developed a stethoscope with active noise reduction using the principle of inverse noise reduction (Comparison of Two Active Noise Cancelling Stethoscopes, International Medical and Health Herald, Issue 14, 2009). Researchers have also proposed a fetal heart sound noise reduction technique using time-domain adaptive windowing (A Time-Domain Adaptive Windowing Fetal Heart Sound Noise Reduction Technique, Authorization Publication No. CN106798553B) to reduce noise. Although noise reduction processing based on the electrical signals of heart and lung sounds can effectively reduce skin and environmental noise, excessive skin and environmental noise can make it difficult to obtain a true heart and lung sound signal. This requires hardware-based noise reduction to mitigate skin and environmental noise. For example, patent CN110868934A discloses a diaphragm and its associated stethoscope head assembly. The membrane and sealant together form a concave conductive space to isolate ambient noise during auscultation. However, because the membrane and sealant are integrally formed and made of the same material, skin noise is easily transmitted through them. Specifically, the membrane easily picks up noise signals, causing environmental interference with the resulting heart and lung sound signals. Summary of the Invention

[0004] To address the above issues, the present invention provides, in one aspect, a noise-reducing stethoscope head, comprising a sound receiving component, a sound guide tube, and a diaphragm. The sound receiving component is trumpet-shaped, the sound guide tube protruding outward from the small end of the sound receiving component, and the end surface of the large end of the sound receiving component is circular. The noise-reducing stethoscope head also includes a noise-reduction ring fixedly mounted on the end surface of the large end of the sound receiving component, and the diaphragm fixedly mounted on the inner wall of the noise-reduction ring. The diaphragm does not contact the sound receiving component, and the noise-reduction ring is a continuous annular cavity.

[0005] The core concept of this invention is to use a noise reduction ring to reduce noise transmitted from the skin to the diaphragm. As noise travels along the skin toward the diaphragm, it is coupled into the ring. Because the ring is an annular cavity, the noise vibrations coupled into the ring are transmitted along a circular path and dissipated within the annular cavity, reducing the noise energy coupled to the diaphragm and thus achieving the desired noise reduction effect.

[0006] Furthermore, the noise reduction ring is filled with liquid so that noise on the skin can be more easily coupled into the noise reduction ring and dissipated inside the noise reduction ring.

[0007] Furthermore, sound-absorbing particles are disposed within the liquid. In the present invention, the size of the sound-absorbing particles is in the micrometer range. Under the influence of noise vibrations, the sound-absorbing particles move and absorb the energy of the noise vibrations, achieving a better noise reduction effect.

[0008] Furthermore, the noise reduction ring includes a skin contact layer and a sound receiving component contact layer. Both the skin contact layer and the sound receiving component contact layer are made of flexible materials, with the skin contact layer being more flexible than the sound receiving component contact layer. The flexible skin contact layer facilitates coupling of noise signals from the skin into the noise reduction ring, while the flexible sound receiving component contact layer facilitates coupling of ambient noise signals from the sound receiving component into the noise reduction ring. This arrangement of the skin contact layer and the sound receiving component contact layer further reduces both skin and ambient noise.

[0009] Furthermore, the skin contact layer within the noise reduction ring is provided with irregularly arranged first protrusions, each made of a flexible material. The sound pickup contact layer within the noise reduction ring is provided with irregularly arranged second protrusions, each made of a flexible material. These first and second protrusions respectively enhance the vibration coupling between the skin contact layer, the sound pickup contact layer, and the fluid within the noise reduction ring, coupling more noise signals from the skin contact layer and the sound pickup contact layer into the noise reduction ring, achieving a more effective noise reduction effect.

[0010] Furthermore, the first protrusion and the second protrusion do not contact the side wall of the noise reduction ring.

[0011] Furthermore, the first protrusion and the second protrusion are cylindrical, and the height of the cylinder is greater than the radius of the cylinder. The height of the first protrusion is greater than the height of the second protrusion.

[0012] On the other hand, the present invention further provides a stethoscope comprising the above-mentioned noise reduction stethoscope head.

[0013] Beneficial effects of the present invention:

[0014] (1) The present invention utilizes a noise reduction ring to reduce noise transmitted from the skin to the vibrating membrane: when noise is transmitted along the skin to the vibrating membrane, it is coupled into the noise reduction ring. Because the noise reduction ring is an annular cavity, the noise vibration coupled into the noise reduction ring can be transmitted along the annular path and dissipated within the annular cavity, reducing the noise energy coupled to the vibrating membrane, thereby achieving the purpose of noise reduction.

[0015] (2) The present invention provides liquid within the noise reduction ring, which allows the noise on the skin to be dissipated more easily within the noise reduction ring, thereby achieving the purpose of noise reduction. Furthermore, the present invention provides sound-absorbing particles within the liquid to help the noise reduction ring better absorb skin noise.

[0016] (3) In the present invention, the contact layer of the sound receiving component on the top of the noise reduction ring is made of a flexible material, which transmits the ambient noise received by the sound receiving component to the noise reduction ring, thereby reducing the ambient noise.

[0017] (4) The present invention provides a first protrusion and a second protrusion on the skin contact layer and the sound receiving component contact layer, thereby enhancing the coupling between the skin contact layer, the sound receiving component contact layer and the fluid in the noise reduction cavity, and is more conducive to reducing skin and environmental noise.

[0018] Based on the above effects, the present invention has good application prospects in the field of heart and lung sound detection technology.

[0019] The present invention will be described in further detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of a noise-reducing stethoscope head.

[0021] Figure 2 This is a schematic diagram of another noise-reducing stethoscope head.

[0022] Figure 3 This is a schematic diagram of a noise reduction loop.

[0023] Figure 4 Schematic diagram of the relative angle relationship between the first protrusion and the vibration membrane.

[0024] In the figure: 1. Sound receiving component; 2. Sound guide pipe; 3. Noise reduction ring; 4. Vibrating membrane; 31. Skin contact layer; 32. Sound receiving component contact layer; 311. First protrusion; 321. Second protrusion. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of this application more clear, the application is further described in detail below with reference to the accompanying drawings and examples.

[0026] The present invention provides a noise reduction stethoscope head, such as Figure 1As shown, it includes a sound receiving component 1, a sound guide tube 2, and a vibration membrane. The sound receiving component 1 is in the shape of a trumpet, and the sound guide tube 2 is the small end of the sound receiving component that protrudes outward. The diameter of the sound guide tube 2 is about one quarter to one half of the diameter of the large end of the trumpet. The material of the sound guide tube 2 is the same as that of the sound receiving component 1, and both are made of elastic material. When used, the sound guide tube 2 can be connected to the sound guide tube, or a microphone can be set at the sound guide tube 2 to build a complete stethoscope system. The microphone can be a condenser microphone or other forms of microphones such as an electret microphone. The end face of the large end of the sound receiving component 1 is circular. The vibration membrane 4 is made of elastic material, and the hardness of the vibration membrane 4 is between 40 and 70. Specifically, the material of the vibration membrane 4 can be thermoplastic rubber or silicone. When the cardiopulmonary sound vibration in the skin is transmitted to the vibration membrane 4, the vibration membrane 4 can generate vibrations with a wider frequency. Specifically, the vibrating membrane 4 can produce a significant response to the frequency bands of heart sound signals (1Hz-800Hz) and lung sound signals (100Hz-2000Hz). The noise reduction stethoscope head also includes a noise reduction ring 3. Figure 1 As shown, the noise reduction ring 3 is fixedly arranged on the end surface of the wide end of the sound receiving component 1, and can be fixed by adhesion. Figure 1 In the figure, the cross-section of the noise reduction ring 3 is rectangular, and the sound receiving component 1 is fixedly connected to the top of the noise reduction ring 3. The vibration membrane 4 is fixedly arranged on the inner wall of the noise reduction ring 3, that is, the vibration membrane 4 is fixedly connected to the inner wall of the rectangle. The vibration membrane 4 does not contact the sound receiving component 1 to prevent the noise in the environment from being directly transmitted to the vibration membrane 4. When the thickness of the sound receiving component 1 is smaller than the area of ​​the top of the noise reduction ring 3, the sound receiving component 1 is arranged on the outside, which reduces the amount of noise transmitted to the vibration membrane 4 through the wall of the noise reduction ring 3, thereby achieving a better noise reduction effect. The noise reduction ring 3 is a through annular cavity. The annular cavity can contain air or other fluids such as liquid. The material of each side wall of the noise reduction ring 3 is different from the material of the vibration membrane 4. The hardness of the material of each side wall of the noise reduction ring 3 is smaller than the hardness of the vibration membrane 4, so that when the bottom of the noise reduction ring 3 contacts the skin, it can absorb more noise signals from the skin. When used, Figure 1 The bottom of the middle diaphragm 4 and the bottom of the noise reduction ring 3 contact the skin.

[0027] The core concept of this invention is to use the noise reduction ring 3 to reduce noise transmitted from the skin to the diaphragm 4. When the noise is transmitted along the skin to the diaphragm 4, it is coupled into the ring 3 through the bottom surface of the noise reduction ring 3. Because the noise reduction ring 4 is a continuous annular cavity, the noise vibration coupled into the noise reduction ring 4 can be transmitted along the continuous annular path and dissipated within the annular cavity, reducing the noise energy coupled to the diaphragm 4, thereby achieving the purpose of noise reduction.

[0028] Preferably, the noise reduction ring 3 is filled with liquid. The liquid can be water or oil, but the liquid needs to fill the noise reduction ring 3. When the bottom of the noise reduction ring 3 vibrates, the mechanical properties of the liquid inside the noise reduction ring 3 and the material at the bottom of the noise reduction ring 3 are more compatible, so that the noise on the skin can be more easily coupled into the inside of the noise reduction ring 3 and dissipated by the liquid inside the noise reduction ring 3. Furthermore, sound-absorbing particles are provided in the liquid. The sound-absorbing material is porous material particles that are used to absorb sound waves in the liquid. When the sound-absorbing particles are porous material particles, the size of the sound-absorbing particles is on the order of microns. Under the action of noise vibration, the movement of the sound-absorbing particles and the porous properties themselves absorb the energy of the noise vibration, achieving a better noise reduction effect. In addition, the sound-absorbing particles can also be asbestos fibers. Asbestos fibers are fibrous, have a certain length and flexibility, and the fiber direction is also disordered, making them more likely to absorb sound waves in the liquid.

[0029] Preferably, if Figure 2 As shown, the noise reduction ring 3 includes a skin contact layer 31 and a sound pickup contact layer 32. The top of the rectangular cross-section of the noise reduction ring 3 forms the sound pickup contact layer 32, the bottom forms the skin contact layer 31, the left side forms the outer surface, and the right side is fixedly connected to the diaphragm 4. During use, the skin contact layer 31 contacts the skin. The sound pickup contact layer 32 is fixedly connected to the sound pickup component 1. Both the skin contact layer 31 and the sound pickup contact layer 32 are made of flexible materials, with the skin contact layer 31 being more flexible than the sound pickup contact layer 32. The flexible skin contact layer 31 facilitates the coupling of noise signals from the skin into the noise reduction ring 3; the flexible sound pickup contact layer 32 facilitates the coupling of ambient noise signals from the sound pickup component 1 into the noise reduction ring 3. This arrangement of the skin contact layer 31 and the sound pickup contact layer 32 further reduces skin and environmental noise. In the present invention, since noise signals transmitted from the skin have a lower frequency, the skin contact layer 31 is configured to be more flexible than the sound pickup contact layer 32, thereby more effectively absorbing noise signals from the skin and the environment.

[0030] Preferably, if Figure 3As shown, first protrusions 311 are provided on the skin contact layer 31 within the noise reduction ring 3. The first protrusions 311 are arranged irregularly and are made of a flexible material. Second protrusions 321 are provided on the sound receiving component contact layer 32 within the noise reduction ring 3. The second protrusions 321 are also arranged irregularly and are also made of a flexible material. The first protrusions 311 and the second protrusions 321 respectively enhance the vibration coupling between the skin contact layer 31, the sound receiving component contact layer 32, and the fluid within the noise reduction ring 3, thereby coupling more noise signals in the skin contact layer 31 and the sound receiving component contact layer 32 into the noise reduction ring 3, achieving a better noise reduction effect. In a specific design, the height of the first protrusions 311 and the second protrusions 321 is greater than 10 microns to enhance the coupling between the skin contact layer 31, the sound receiving component contact layer 32, and the fluid within the noise reduction ring 3. Furthermore, when the first and second protrusions 311, 321 oscillate, they avoid contacting the sidewalls of the noise reduction ring 3, preventing the first and second protrusions 311, 321 from directly transmitting vibrations to the diaphragm 4. In a specific design, the first and second protrusions 311, 321 can be cylindrical, with the height of the cylinder greater than the radius, to achieve greater flexibility. The height of the first protrusion 311 is greater than the height of the second protrusion 321, so that lower-frequency noise in the skin contact layer 31 is coupled into the fluid within the noise reduction ring 3 through the first protrusion 311.

[0031] Preferably, if Figure 4 As shown, the first protrusion 311 and the second protrusion 321 can also be in the shape of a rectangular column. The length and width of the rectangular column are not equal. The length of the rectangle is not along the radial direction of the diaphragm 4. In this way, the first protrusion 311 and the second protrusion 321 can decompose the vibration along the radial direction of the diaphragm 4, thereby reducing the impact of noise on the diaphragm 4.

[0032] In another aspect, the present invention further provides a stethoscope comprising the aforementioned noise-reducing stethoscope head. Conventional stethoscopes, in addition to the noise-reducing stethoscope head, also include a sound guide tube and an ear hook. Electronic stethoscopes, in addition to the noise-reducing stethoscope head, also include a sound pickup, a signal transmission device, a processor, and the like.

[0033] In summary, the present invention provides a noise-reducing stethoscope head and stethoscope. The core concept of the present invention is to utilize a noise-reduction ring 3 to reduce noise transmitted from the skin to the diaphragm 4. As the noise propagates along the skin toward the diaphragm 4, it is coupled into the noise-reduction ring 3. Because the noise-reduction ring 3 is an annular cavity, the noise vibrations coupled into the ring 3 are transmitted along a circular path and dissipated within the annular cavity, reducing the noise energy coupled to the diaphragm 4, thereby achieving the purpose of noise reduction. The present invention has promising application prospects in the field of cardiopulmonary sound detection technology.

[0034] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A noise reduction stethoscope head, comprising a sound receiving component, a sound guide tube, and a vibrating membrane, wherein the sound receiving component is trumpet-shaped, the sound guide tube is a small end of the sound receiving component that protrudes outward, and the end surface of the large end of the sound receiving component is circular, characterized in that: The device further comprises a noise reduction ring, wherein the noise reduction ring is fixedly arranged on the end surface of one end of the large opening of the sound receiving component, the vibration membrane is fixedly arranged on the inner wall of the noise reduction ring, the vibration membrane does not contact the sound receiving component, the noise reduction ring is a through annular cavity, the noise reduction ring comprises a skin contact layer and a sound receiving component contact layer, the material of the skin contact layer and the material of the sound receiving component contact layer are flexible materials, the flexibility of the skin contact layer is greater than the flexibility of the sound receiving component contact layer; the material of each side wall of the noise reduction ring is different from the material of the vibration membrane, and the hardness of the material of each side wall of the noise reduction ring is less than the hardness of the vibration membrane; The noise reduction ring is filled with liquid, and a first protrusion is provided on the skin contact layer in the noise reduction ring, and the first protrusion is made of a flexible material. A second protrusion is provided on the sound receiving component contact layer in the noise reduction ring, and the second protrusion is made of a flexible material. The heights of the first protrusion and the second protrusion are greater than 10 microns, and when the first protrusion and the second protrusion shake, the first protrusion and the second protrusion do not contact the side wall of the noise reduction ring.

2. The noise reduction stethoscope head according to claim 1, wherein: Sound-absorbing particles are arranged in the liquid.

3. The noise reduction stethoscope head according to claim 2, wherein: The first protrusion and the second protrusion are cylindrical, and the height of the cylinder is greater than the radius of the cylinder.

4. The noise reduction stethoscope head according to claim 3, wherein: The height of the first protrusion is greater than the height of the second protrusion.

5. A stethoscope, characterized in that: The invention comprises the noise reduction stethoscope head according to any one of claims 1 to 4.

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