A multi-layer heterogeneous shielding structure-based ECG main cable and a manufacturing method thereof

Abstract

The application discloses a multi-layer heterogeneous shielding structure-based ECG main cable and a manufacturing method thereof, and relates to the cable field.The ECG main cable comprises a core group, a composite shielding layer structure and an outer sheath which are sequentially arranged outside the core group, the core group comprises a plurality of twisted pairs, each twisted pair is composed of a signal wire and a ground wire which are asymmetrically twisted, the composite shielding layer structure is composed of a plurality of composite shielding segments which are arranged at intervals along the axial direction of the cable, and the adjacent composite shielding segments are filled with a resistive material, each composite shielding segment comprises, from inside to outside, a spiral copper foil layer, a silver wire polyester braided layer and an amorphous silicon carbide coating layer, the spiral copper foil layer is arranged outside the plurality of twisted pairs, and the outer sheath is arranged outside the amorphous silicon carbide coating layer.The application can realize broadband shielding compatibility, and can realize pure physical structure noise reduction without additional electronic elements, so that the cable is light and low in cost.

Description

Technical Field

[0001] The present invention relates to the field of cables, and in particular to an electrocardiogram (ECG) main cable based on a multi-layer heterogeneous shielding structure and a manufacturing method thereof. Background Art

[0002] ECG monitoring is the primary basis for monitoring and diagnosing cardiovascular disease. It typically involves the coordinated use of electrodes, cables, and monitoring equipment. During long monitoring sessions, the cables are constantly bending and moving, often generating friction and noise that interfere with ECG monitoring.

[0003] The traditional ECG pure cable structure has the following problems: insufficient high-frequency shielding: the attenuation of a single-layer metal braided shield in the frequency band >100MHz is less than 30dB; sensitivity to mechanical noise: static noise is generated by friction between internal wires when the cable is bent; grounded distributed capacitance coupling: the continuous grounding of the shield layer leads to the amplification of common-mode interference.

[0004] Current noise reduction solutions mainly rely on external filtering circuits or additional shielding boxes, but the additional equipment makes the cables bulky and costly. Summary of the Invention

[0005] In view of the above problems, embodiments of the present invention are proposed to provide an ECG main cable based on a multi-layer heterogeneous shielding structure and a manufacturing method thereof that overcomes the above problems or at least partially solves the above problems.

[0006] A main ECG cable based on a multi-layer heterogeneous shielding structure comprises a core group and a composite shielding layer structure and an outer sheath sequentially covering the core group. The core group comprises a plurality of twisted pairs, each of which is formed by asymmetrically twisting a signal line and a ground line.

[0007] The composite shielding layer structure is composed of multiple composite shielding segments spaced apart along the axial direction of the cable, and the spaces between adjacent composite shielding segments are filled with resistive material;

[0008] The composite shielding segment includes, from the inside to the outside, a spiral copper foil layer, a silver polyester braided layer, and an amorphous silicon carbide coating, wherein the spiral copper foil layer is coated on the outside of the plurality of twisted pair wires;

[0009] The outer sheath is coated on the outside of the amorphous silicon carbide coating.

[0010] Preferably, an FEP foam filling layer is filled between the multiple groups of twisted wire pairs.

[0011] Preferably, the signal wire and the ground wire are twisted alternately, and the twisting directions thereof are alternately changed every 10 cm; wherein the twist ratio is 1:4.

[0012] Preferably, the length of each composite shielding segment is 15 cm, and the interval between adjacent composite shielding segments is 10 cm-20 cm; the resistance value of the resistive material is 100Ω-10kΩ.

[0013] Preferably, the resistive material is a polymer conductive adhesive, and the volume resistivity of the polymer conductive adhesive is 10^3Ω·cm.

[0014] Preferably, the outer surface of the outer sheath is provided with a honeycomb structure, and the pit depth of the honeycomb structure is 30-80 μm and the spacing is 100-300 μm.

[0015] Preferably, the outer sheath is made of silicone rubber.

[0016] Preferably, the spiral copper foil layer is formed by spirally winding a copper foil tape around the outside of the plurality of twisted pairs, wherein the copper foil tape has a thickness of 0.02 mm and a coverage of 100%;

[0017] The silver polyester braided layer is woven from a blended mesh of silver wire and polyester, wherein the silver wire accounts for 60%, the braiding angle is 30°, and the mesh count is 150;

[0018] The amorphous silicon carbide coating is formed by magnetron sputtering deposition, wherein the coating thickness is 100 nm and the resistivity is 10^2Ω·m.

[0019] Preferably, the signal wires of each group of twisted wire pairs are coated with a composite insulation layer, and the composite insulation layer comprises, from inside to outside, an FEP inner layer, a TPU middle layer and an organic silicone outer layer.

[0020] A method for manufacturing the above-mentioned ECG main cable comprises the following steps:

[0021] Multiple signal lines and multiple ground lines are matched one by one and twisted asymmetrically to form multiple twisted pairs;

[0022] Helically winding a spiral copper foil layer around the outside of the plurality of twisted pairs, and sequentially coating the outside of the silver polyester braided layer with a silver polyester braided layer and an amorphous silicon carbide coating to form a composite shielding layer structure;

[0023] Cutting the composite shielding layer structure into multiple composite shielding segments at preset intervals along the axial direction of the cable, and filling resistive material between the multiple composite shielding segments;

[0024] An outer sheath is wrapped around the plurality of composite shielding sections and the resistive material.

[0025] This application specifically includes the following advantages:

[0026] In an embodiment of the present application, the core group includes a plurality of twisted pairs through a core group and a composite shielding layer structure and an outer sheath sequentially coated on the outside of the core group, and the twisted pairs are composed of asymmetrically twisted signal lines and ground lines; the composite shielding layer structure is composed of a plurality of composite shielding segments spaced apart along the axial direction of the cable, and resistive material is filled between adjacent composite shielding segments; the composite shielding segments sequentially include a spiral copper foil layer, a silver-wire polyester braided layer and an amorphous silicon carbide coating from the inside to the outside, and the spiral copper foil layer is coated on the outside of the plurality of twisted pairs; the outer sheath is coated on the outside of the amorphous silicon carbide coating. The twisted pair is composed of a signal line and a ground line twisted asymmetrically, which can reduce crosstalk between the wires and thus reduce noise; and combined with three layers of heterogeneous shielding layers, namely a spiral copper foil layer, a silver polyester braided layer and an amorphous silicon carbide coating, it can respectively shield low-frequency magnetic fields, medium- and high-frequency radiation and GHz microwaves, achieve full-band electromagnetic shielding and further reduce cable noise; and by segmenting the composite shielding layer structure and using resistive materials for weak connection, a distributed RC filter is formed. By segmenting the shielding grounding, the common-mode current loop can be blocked, thereby effectively reducing noise, improving signal integrity and anti-interference capabilities. The present application can achieve broadband shielding compatibility and pure physical structure noise reduction, without the need for additional electronic components to improve the noise reduction effect, making the cable light and low-cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for the description of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0028] Figure 1 This is a schematic structural diagram of an ECG main cable based on a multi-layer heterogeneous shielding structure according to the present invention;

[0029] Figure numerals: 1, wire core group; 11, twisted pair; 111, signal line; 112, ground wire; 113, composite insulation layer; 21, spiral copper foil layer; 22, silver wire polyester braided layer; 23, amorphous silicon carbide coating; 2, composite shielding layer structure; 3, outer sheath; 4, FEP foam filling layer. DETAILED DESCRIPTION

[0030] To make the objectives, features, and advantages of this application more readily apparent, the present application is further described below in conjunction with the accompanying drawings and specific embodiments. It is apparent that the embodiments described are only a portion of the embodiments of this application, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments in this application without inventive effort are also within the scope of protection of this application.

[0031] Reference Figure 1 , showing a schematic structural diagram of an ECG main cable based on a multi-layer heterogeneous shielding structure according to the present invention, which specifically may include the following structures: a core group 1, and a composite shielding layer structure 2 and an outer sheath 3 sequentially coated on the outside of the core group 1, the core group 1 including multiple groups of twisted pairs 11, each of which is composed of a signal line 111 and a ground line 112 twisted asymmetrically;

[0032] The composite shielding layer structure 2 is composed of multiple composite shielding segments spaced apart along the axial direction of the cable, and the spaces between adjacent composite shielding segments are filled with resistive material;

[0033] The composite shielding segment includes, from the inside to the outside, a spiral copper foil layer 21, a silver polyester braided layer 22, and an amorphous silicon carbide coating 23. The spiral copper foil layer 21 is coated on the outside of the plurality of twisted pairs 11.

[0034] The outer sheath 3 is coated on the outside of the amorphous silicon carbide coating 23 .

[0035] In an embodiment of the present application, through a core group 1 and a composite shielding layer structure 2 and an outer sheath 3 sequentially coated on the outside of the core group 1, the core group 1 includes a plurality of twisted pair wires 11, and the twisted pair wires 11 are composed of asymmetrically twisted signal wires 111 and ground wires 112; the composite shielding layer structure 2 is composed of a plurality of composite shielding segments spaced apart along the axial direction of the cable, and resistive material is filled between adjacent composite shielding segments; the composite shielding segments sequentially include a spiral copper foil layer 21, a silver wire polyester braided layer 22 and an amorphous silicon carbide coating 23 from the inside to the outside, and the spiral copper foil layer 21 is coated on the outside of the plurality of twisted pair wires 11; the outer sheath 3 is coated on the outside of the amorphous silicon carbide coating 23. The twisted pair 11 is composed of a signal line 111 and a ground line 112 twisted asymmetrically, which can reduce crosstalk between wires and thus reduce noise; and combined with three layers of heterogeneous shielding layers, namely the spiral copper foil layer 21, the silver polyester braided layer 22 and the amorphous silicon carbide coating 23, it can respectively shield low-frequency magnetic fields, medium- and high-frequency radiation and GHz microwaves, achieve full-band electromagnetic shielding and further reduce cable noise; and by segmenting the composite shielding layer structure 2 and using resistive materials for weak connection, a distributed RC filter is formed, and the segmented shielding grounding can block the common-mode current loop, thereby effectively reducing noise and improving signal integrity and anti-interference capabilities. The present application can achieve broadband shielding compatibility and pure physical structure noise reduction, and improve the noise reduction effect without the need for additional electronic components, making the cable light and low-cost.

[0036] Next, an electrocardiographic main cable based on a multi-layer heterogeneous shielding structure in this exemplary embodiment will be further described.

[0037] In the embodiment of the present application, the core wire group includes a plurality of twisted pairs of wires 11, each twisted pair of wires 11 being twisted asymmetrically by a signal wire 111 and a ground wire 112. The asymmetric twisted pair of wires 11 reduces the crosstalk between the wires, thereby reducing the noise caused by the crosstalk, avoiding signal distortion and misjudgment.

[0038] As an example, the plurality of twisted pairs of wires 11 are filled with a FEP (fluorinated ethylene propylene) foamed filling layer, which has a density of 0.6 g / cm3 and can buffer mechanical stress, thereby reducing the friction noise between the plurality of twisted pairs of wires 11.

[0039] As an example, the signal wire 111 and the ground wire 112 are alternately twisted, and the twisting direction is alternately changed every 10 cm; wherein the twist pitch ratio is 1:4. That is, the twisting direction alternately uses left-handed and right-handed rotation, and is switched every 10 cm, which can reduce the skin effect interference, thereby reducing electromagnetic interference and avoiding high-frequency noise. The diameter of the signal wire 111 is preferably 0.08 mm, and the diameter of the ground wire 112 is preferably 0.12 mm; the signal wire 111 and the ground wire 112 are preferably silver-plated copper wires, the silver layer has a thickness of 2 μm, and the direct current resistance is ≤0.1 Ω / m.

[0040] By combining the FEP foamed filling layer 4 with the alternating twisting direction, a dynamic stress dissipation structure can be formed, which effectively eliminates the wire friction noise caused by bending.

[0041] In the embodiment of the present application, the composite shielding layer structure 2 is composed of a plurality of composite shielding segments arranged along the cable axis at intervals, and the adjacent composite shielding segments are filled with a resistive material. The segmented shielding grounding design and the resistive weak connection can effectively suppress common-mode current.

[0042] As an example, the composite shielding layer structure 2 is divided into independent shielding segments, each of the composite shielding segments has a length of 15 cm, and the adjacent composite shielding segments have a spacing distance of 10 cm-20 cm; the resistive material has a resistance value of 100 Ω-10 kΩ.

[0043] Specifically, the adjacent segments are weakly connected by a high-molecular conductive adhesive (resistance 1 kΩ), and the high-molecular conductive adhesive has a volume resistivity of 10^3 Ω·cm, forming a distributed RC filter. By distributed insulation grounding, the common-mode current loop is blocked, thereby reducing high-frequency noise.

[0044] In the embodiment of the present application, the composite shielding segment comprises, from inside to outside, a spiral copper foil layer 21, a silver filament polyester woven layer 22, and an amorphous silicon carbide coating layer 23. The spiral copper foil layer 21 is wrapped outside the plurality of twisted pairs 11. Through the three-layer heterogeneous shielding structure, from inside to outside, low-frequency magnetic field, medium-high frequency radiation, and GHz microwave are covered, and electromagnetic interference from kHz to GHz is realized, achieving full-band electromagnetic shielding.

[0045] As an example, the spiral copper foil layer 21 is formed by spirally winding a copper foil tape outside the plurality of twisted pairs 11, wherein the thickness of the copper foil tape is 0.02 mm, the width is 5 mm, and the coverage is 100%. Specifically, during the spiral winding process, the edges of the copper foil tape overlap by 1 mm, and the overlapping part is coated with conductive epoxy resin (resistance ≤0.01 Ω) to suppress low-frequency magnetic fields.

[0046] The silver filament polyester woven layer 22 is woven from woven silver filaments and polyester blended net, wherein the proportion of silver filaments is 60%, the weaving angle is 30°, and the gauge is 150. Through the fabric pores of the silver filament polyester woven layer 22, high-frequency electromagnetic waves can be scattered, thereby isolating them.

[0047] The amorphous silicon carbide coating layer 23 is formed by magnetron sputtering deposition, wherein the coating thickness is 100 nm, and the resistivity is 10^2 Ω·m. The amorphous silicon carbide coating layer 23 as the outermost shielding layer can absorb GHz band radiation. Specifically, the preparation of the coating is performed in a vacuum chamber (5×10^-3 Pa) by magnetron sputtering deposition of amorphous silicon carbide, wherein the target power density is 10 W / cm².

[0048] In a specific test, the overall shielding effectiveness of the composite shielding layer structure 2 is: 10 kHz-100 MHz: ≥90 dB; 100 MHz-2 GHz: ≥60 dB (according to IEC 61196-1 standard).

[0049] In the embodiment of the present application, the outer sheath 3 is wrapped outside the amorphous silicon carbide coating layer 23 for protection and insulation of the cable.

[0050] As an example, the outer surface of the outer sheath 3 is provided with a honeycomb structure, and the depth of the recesses of the honeycomb structure is 30-80 μm, and the pitch is 100-300 μm. The surface honeycomb structure can reduce the accumulation of triboelectric charges, thereby reducing the generation of noise.

[0051] As an example, the outer sheath 3 is a medical-grade silicone rubber (Shore hardness 50A), and a honeycomb structure is formed on the outer surface by laser etching, which not only has good protection effect but also reduces friction noise.

[0052] As an example, the signal wires 111 of each twisted pair 11 are coated with a composite insulation layer 113. This composite insulation layer 113 comprises, from inside to outside, an inner FEP layer, a middle TPU (thermoplastic polyurethane) layer, and an outer silicone layer. These three layers are co-extruded onto the exterior of the signal wires 111, with a total thickness of 0.5 mm. This three-layer composite insulation of FEP, TPU, and silicone significantly improves the insulation performance of the signal wires 111, providing excellent tear resistance and electromagnetic absorption.

[0053] The present application also provides a method for manufacturing an ECG main cable, comprising the following steps:

[0054] Fabrication of core group 1: Multiple signal wires 111 and multiple ground wires 112 are aligned and asymmetrically twisted to form multiple twisted pairs 11. Specifically, a composite insulation layer 113 is co-extruded around each silver-plated copper signal wire 111 with a diameter of 0.08mm. The insulation layer consists of a 0.1mm inner layer of FEP, a 0.3mm tear-resistant middle layer of TPU, and a 0.1mm outer layer of silicone, forming a three-layer tear-resistant composite insulation layer 113. The signal wires 111 are twisted with silver-plated copper ground wires 112 with a 0.12mm diameter at a 1:4 lay ratio, with the twist direction switching every 10cm to form multiple twisted pairs 11. FEP foam (30% expansion ratio) is then injected between the twisted pairs 11, preheated at 60°C, and then molded to set the shape.

[0055] Composite shielding layer structure 2 is fabricated and processed as follows: A 5mm wide spirally wound copper foil tape is spirally wrapped around the multiple twisted pairs 11. The overlapping portions of the copper foil tape are coated with a conductive epoxy resin (resistance ≤ 0.01Ω) to form a spiral copper foil layer 21. A silver-polyester braided mesh is woven using a 30° braiding angle and a tension of 0.5N / cm. The silver-polyester braided layer 22 is then overlaid on the outside of the spiral copper foil layer 21. Amorphous silicon carbide is deposited by magnetron sputtering in a vacuum chamber (5×10^-3 Pa) with a target power density of 10W / cm² to form an amorphous silicon carbide coating 23. This coating is then overlaid on the outside of the silver-polyester braided layer 22, forming a three-layer composite shielding layer structure 2.

[0056] Segmented shielding design: The composite shielding layer structure 2 is cut into multiple composite shielding segments at predetermined intervals along the cable axis, and the spaces between these segments are filled with resistive material. Specifically, a laser cutter is used to create 0.2mm wide annular notches every 15cm in the composite shielding layer structure 2. These notches are then filled with a carbon black-doped polymer conductive adhesive with a volume resistivity of 10^3 Ω·cm.

[0057] Coating and surface treatment of outer sheath 3: The outer sheath 3 is coated on the exterior of the multi-segment composite shielding segment and the resistive material. Specifically, a honeycomb structure is etched on the outer surface of the medical silicone rubber using a 355nm UV laser (power 20W, scanning speed 500mm / s). The honeycomb structure has a pit depth of 50μm and a pitch of 200μm, forming the outer sheath 3.

[0058] Beneficial effects of the embodiments of the present application:

[0059] The asymmetric twisted pair 11 reduces crosstalk between conductors, and the FEP foam filling layer 4 and the alternating twisting direction design eliminate the friction noise of the conductors caused by bending. Combined with three layers of heterogeneous shielding layers (copper foil + silver wire braid + amorphous silicon carbide), full-band electromagnetic shielding is achieved. The segmented shield grounding design suppresses common-mode current through resistive connection, and the surface honeycomb structure reduces friction charge accumulation, significantly improving the quality of ECG signals without the need for external circuits. This application relies entirely on the cable body material and geometric design, without the need for additional electronic components. Broadband noise suppression is achieved only through the cable body structure, achieving pure physical structural noise reduction, which can reduce costs and cable weight.

[0060] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0061] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or terminal device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or terminal device that includes the element.

[0062] The above is a detailed introduction to the ECG main cable based on a multi-layer heterogeneous shielding structure and its manufacturing method provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technical personnel in this field, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. An electrocardiogram main cable based on a multi-layer heterogeneous shielding structure, characterized in that: The invention comprises a core group and a composite shielding layer structure and an outer sheath sequentially coated on the outside of the core group, wherein the core group comprises a plurality of twisted pairs, wherein the twisted pairs are composed of a signal line and a ground line twisted asymmetrically; the signal line and the ground line are twisted alternately, and the twisting direction thereof is alternated every 10 cm; wherein the lay ratio is 1:4; The composite shielding layer structure is composed of multiple composite shielding segments spaced apart along the axial direction of the cable, and the spaces between adjacent composite shielding segments are filled with a resistive material; each composite shielding segment is 15 cm long, and the spacing between adjacent composite shielding segments is 10 cm-20 cm; the resistance value of the resistive material is 100 Ω-10 kΩ; the resistive material is a polymer conductive adhesive, and the volume resistivity of the polymer conductive adhesive is 10^3 Ω·cm; The composite shielding segment includes, from the inside to the outside, a spiral copper foil layer, a silver polyester braided layer, and an amorphous silicon carbide coating, wherein the spiral copper foil layer is coated on the outside of the plurality of twisted pair wires; The outer sheath is coated on the outside of the amorphous silicon carbide coating.

2. The ECG main cable based on a multi-layer heterogeneous shielding structure according to claim 1 is characterized in that: An FEP foam filling layer is filled between the multiple twisted wire pairs.

3. The ECG main cable based on a multi-layer heterogeneous shielding structure according to claim 1 or 2, characterized in that: The outer surface of the outer sheath is provided with a honeycomb structure, and the pit depth of the honeycomb structure is 30-80 μm and the spacing is 100-300 μm.

4. The ECG main cable based on a multi-layer heterogeneous shielding structure according to claim 3 is characterized in that: The outer sheath is made of organic silicone rubber.

5. The ECG main cable based on a multi-layer heterogeneous shielding structure according to claim 1, characterized in that: The spiral copper foil layer is formed by spirally winding a copper foil tape around the outside of the plurality of twisted pairs, wherein the copper foil tape has a thickness of 0.02 mm and a coverage rate of 100%; The silver polyester braided layer is woven from a blended mesh of silver wire and polyester, wherein the silver wire accounts for 60%, the braiding angle is 30°, and the mesh count is 150; The amorphous silicon carbide coating is formed by magnetron sputtering deposition, wherein the coating thickness is 100 nm and the resistivity is 10^2Ω·m.

6. The ECG main cable based on a multi-layer heterogeneous shielding structure according to claim 1, characterized in that: The signal wires of each twisted pair are covered with a composite insulation layer, which comprises a FEP inner layer, a TPU middle layer and a silicone outer layer from the inside to the outside.

7. A method for manufacturing an ECG main cable according to any one of claims 1 to 6, characterized in that: The steps include: Multiple signal lines and multiple ground lines are matched one by one and twisted asymmetrically to form multiple twisted pairs; Helically winding a spiral copper foil layer around the outside of the plurality of twisted pairs, and sequentially coating the outside of the silver polyester braided layer with a silver polyester braided layer and an amorphous silicon carbide coating to form a composite shielding layer structure; Cutting the composite shielding layer structure into multiple composite shielding segments at preset intervals along the axial direction of the cable, and filling resistive material between the multiple composite shielding segments; An outer sheath is wrapped around the plurality of composite shielding sections and the resistive material.

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