Special transmission cable for medical nuclear magnetic equipment

Abstract

The invention belongs to the technical field of medical cables, and discloses a special transmission cable for medical nuclear magnetic equipment, which is provided with coaxial lines, a filling layer, a wrapping layer and an outer sheath, and is characterized in that the coaxial lines are composed of conductors, insulating layers, an inner braided shielding layer and an inner sheath which are sequentially distributed outwards, and the coaxial lines are divided into five inner layers and eleven outer layers; the outer layer is positioned outside the inner layer; all gaps in the outer layer or all gaps in the wrapping layer are filled with the filling layer; the whole transmission cable is of a coaxial circular layered symmetrical structure. The system has the following main beneficial technical effects: the system is compatible with mainstream medical nuclear magnetic equipment, and magnetic field interference and thermal damage potential safety hazards are eliminated; complex electromagnetic environment interference is resisted, internal signal crosstalk is eliminated, high-fidelity transmission is guaranteed, image definition is improved, the artifact problem is completely eradicated, and clinical precise diagnosis is supported. The sterilization resistance, the high and low temperature resistance, the chemical disinfection resistance, the wear resistance and the high and low temperature resistance are better; the service life of the reciprocating bending is longer, and the service life of the cable is prolonged; the production is easier.

Description

Technical Field

[0001] This invention belongs to the field of medical cable technology, and in particular relates to a transmission cable specifically for medical MRI equipment. Background Technology

[0002] Medical magnetic resonance imaging (MRI) equipment is a core medical device for high-precision, non-invasive clinical diagnosis. During operation, it generates strong static magnetic fields, gradient fields, and high-frequency radio frequency pulses of 1.5T, 3.0T, and above. The accompanying transmission cable, as the core carrier for power transmission, radio frequency signal transmission and reception, control command transmission, and physiological signal acquisition, directly determines the imaging accuracy, operational stability, and clinical safety of the equipment. Currently, the transmission cables used with medical MRI equipment are mostly general-purpose medical cables, not specifically designed for the strong magnetic field environment, high-precision signal transmission, medical-grade safety protection, and repeated sterilization and disinfection requirements of MRI equipment. This results in many unavoidable technical defects, the main technical problems of which are as follows.

[0003] 1. Existing MRI equipment cables have poor non-magnetic compatibility, and are prone to eddy current heating and magnetic field distortion in strong magnetic field environments, which interfere with the imaging accuracy of the equipment and pose clinical safety hazards.

[0004] 2. Existing cables have insufficient resistance to electromagnetic interference. In complex electromagnetic environments with strong magnetic fields, signal distortion, attenuation, and crosstalk are severe, resulting in artifacts in MRI images and low diagnostic accuracy.

[0005] 3. Existing medical cables have poor sterilization resistance, are prone to aging and damage after repeated disinfection, and experience rapid performance degradation, which does not meet medical infection control requirements.

[0006] 4. Existing cables do not meet biocompatibility standards and do not comply with relevant medical device standards, posing a risk of contact safety during clinical use.

[0007] 5. Existing cables have poor bending and fatigue resistance, and are prone to core breakage and short service life under high-frequency reciprocating movement and frequent bending scenarios.

[0008] CN223321053U discloses a lightweight, anti-attenuation 16-core triple-shielded coaxial cable, comprising 16 coaxial cores arranged in a square and forming a cable core together with a polyester short fiber buffer core. Each coaxial core includes a center conductor, a foamed FEP insulation layer, a copper-plastic composite longitudinally wrapped inner shielding layer, a tinned copper wire braided intermediate shielding layer, a copper-plastic composite wrapped outer shielding layer, and a polyurethane covering layer. The shielding density of the tinned copper wire braided intermediate shielding layer is 40% to 60%. The cable core is sequentially covered with a para-type fully aromatic copolyamide stretched fiber braided isolation mesh and an irradiated cross-linked high-density polyethylene outer sheath. However, due to its structure and other factors, it cannot solve the aforementioned technical problems, and its space utilization is low. The four-wire, four-group arrangement of the coaxial cores results in wasted space, a large outer diameter, and excessive material consumption. Summary of the Invention

[0009] To address the aforementioned shortcomings, the present invention aims to provide a dedicated transmission cable for medical MRI equipment that features a completely non-magnetic design, high resistance to electromagnetic interference, high-precision signal transmission, medical-grade biosafety, resistance to repeated sterilization, and a long service life. This is achieved through the following technical solution.

[0010] A transmission cable for medical MRI equipment comprises sixteen coaxial cables, a filler layer, a wrapping layer, and an outer sheath. Its features include: the coaxial cables consisting of a conductor, an insulation layer, an inner braided shielding layer, and an inner sheath; the insulation layer covers the conductor, the inner braided shielding layer covers the insulation layer, and the inner sheath covers the inner braided shielding layer; the inner layer has five coaxial cables, with their axes evenly distributed on a first circumference, and adjacent coaxial cables in the inner layer being externally tangent; the outer layer has eleven coaxial cables, with their axes evenly distributed on a second circumference, and adjacent coaxial cables in the outer layer being externally tangent; the outer layer is located outside the inner layer; the filler layer fills all gaps within the outer layer, or fills all gaps within the wrapping layer; the transmission cable as a whole has a coaxial circular layered symmetrical structure.

[0011] The above-mentioned transmission cable for medical MRI equipment is characterized in that: the conductors are all non-magnetic, high-purity, oxygen-free silver-plated copper wires, which are electrolytically silver-plated, continuously annealed during the wire drawing process, and formed by stranding of bundled wires and re-twisted wires, with a stranding pitch of 8-12 times the outer diameter of the strand.

[0012] The above-mentioned transmission cable for medical MRI equipment is characterized in that: the insulation layer is made of medical-grade FEP material with low dielectric constant, the outer diameter of the insulation layer is 0.84±0.05mm, and the dielectric constant is ≤2.1.

[0013] The aforementioned transmission cable for medical MRI equipment is characterized in that: the braided shielding layer is made of 16×3 / 0.1±0.008mm silver-plated copper wire, with a braiding density ≥95% and an electromagnetic shielding effectiveness ≥60dB. Here, 16×3 / 0.1 refers to the braiding specification, which is completed by using 16 spindles of 3 strands of 0.10mm braided monofilaments; 0.1±0.008mm refers to the diameter of the monofilament.

[0014] The aforementioned transmission cable for medical MRI equipment is characterized in that: the inner sheath is made of medical-grade FEP material with a thickness of 1.8±0.10mm.

[0015] The above-mentioned transmission cable for medical MRI equipment is characterized in that: the filling layer is made of high-strength non-magnetic medical degreased cotton yarn.

[0016] The aforementioned transmission cable for medical MRI equipment is characterized in that: both the inner and outer layers are produced using 100% untwisting equipment, and the stranding pitch of the inner and outer layers is controlled to be 8-12 times the outer diameter of each layer.

[0017] The above-mentioned transmission cable for medical MRI equipment is characterized in that: the wrapping layer is made of double-layered overlapping non-magnetic non-woven fabric with an overlap rate of ≥25%.

[0018] The aforementioned transmission cable for medical MRI equipment is characterized in that: the outer sheath is made of medical-grade sterile and wear-resistant polyurethane material or medical-grade material.

[0019] This invention offers the following key technical advantages: It is compatible with mainstream medical MRI equipment of 1.5T, 3.0T, and above, eliminating the safety hazards of magnetic field interference and thermal damage; it effectively resists the complex electromagnetic environment interference from the strong magnetic field and high-frequency radio frequency pulses of MRI equipment, while eliminating internal signal crosstalk, ensuring high-fidelity transmission of weak MRI echo signals, significantly improving image clarity, eliminating artifact problems, and supporting accurate clinical diagnosis; it boasts superior resistance to sterilization and high / low temperatures; it also exhibits superior resistance to chemical disinfection, wear, and high / low temperatures, adapting to the stringent infection control and usage requirements of medical scenarios; it has a longer lifespan due to reciprocating bending, significantly extending the cable's service life; it has a reasonable structure, stable cabling process, high batch product consistency, and strong versatility and expandability. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the cross-sectional structure of the application.

[0021] Figure 2 This is the test result sheet for the application.

[0022] Figure 3 for Figure 1A schematic diagram of the cross-sectional structure after adding the axis of symmetry. Detailed Implementation

[0023] To enable those skilled in the art to better understand and implement this patent, the markings in the accompanying drawings are explained in detail below.

[0024] In the diagram: 1—Conductor, 2—Insulation layer, 3—Inner braided shielding layer, 4—Inner sheath, 5—Filling layer, 6—Wrapping layer, 7—Outer sheath.

[0025] Please see Figures 1 to 3 A transmission cable specifically designed for medical MRI equipment comprises 16 coaxial cables, a filler layer 5, a wrapping layer 6, and an outer sheath 7. Its distinguishing feature is that the coaxial cables consist of a conductor 1, an insulation layer 2, an inner braided shielding layer 3, and an inner sheath 4. The insulation layer covers the conductor, the inner braided shielding layer covers the insulation layer, and the inner sheath 4 covers the inner braided shielding layer. The inner layer has five coaxial cables, numbered as follows: Figure 1 The innermost layer has 1-5 coaxial lines. All coaxial lines in the inner layer are evenly distributed on the first circumference, and adjacent coaxial lines in the inner layer are externally tangent. The outer layer has eleven coaxial lines, numbered as follows: Figure 1 The inner layer consists of 6-16 layers, and the outer layer consists of all coaxial lines evenly distributed on the second circumference. Adjacent coaxial lines in the outer layer are externally tangent. The outer layer is located outside the inner layer. The filling layer fills all gaps within the outer layer, or the filling layer fills all gaps within the wrapping layer. The transmission cable as a whole has a coaxial circular layered symmetrical structure.

[0026] The numbering of the coaxial lines in the diagram is not limited to the numbering used for ease of explanation; other reasonable numbering methods may be used.

[0027] See Figure 3 The aforementioned transmission cable for medical MRI equipment is characterized by a coaxial circular layered symmetrical structure, meaning that the symmetrical axis A of the inner layer coincides with the symmetrical axis B of the outer layer. In the first structure, one coaxial line of the inner layer is located directly below one coaxial line of the outer layer; in the diagram, number 1 is located directly below number 8. In the second structure, one coaxial line of the inner layer is located directly below the gap formed by two adjacent coaxial lines of the outer layer; in the diagram, number 1 can be located directly below numbers 8 and 9. Thus, in both structures, the inner and outer layers and the entire cable are symmetrical.

[0028] The aforementioned transmission cable for medical MRI equipment is characterized in that: the coaxial cable is model RG178, and the coaxial cable can also be referred to as RG178 coaxial cable.

[0029] The above-mentioned transmission cable for medical MRI equipment is characterized in that: the conductors are all non-magnetic, high-purity, oxygen-free silver-plated copper wires, which are electrolytically silver-plated, continuously annealed during the wire drawing process, and formed by stranding of bundled wires and re-twisted wires, with a stranding pitch of 8-12 times the outer diameter of the strand.

[0030] The above-mentioned transmission cable for medical MRI equipment is characterized in that: the insulation layer is made of medical-grade FEP material with low dielectric constant, the outer diameter of the insulation layer is 0.84±0.05mm, and the dielectric constant is ≤2.1.

[0031] The above-mentioned transmission cable for medical MRI equipment is characterized in that: the braided shielding layer is made of 16×3 / 0.1±0.008mm silver-plated copper wire, the braiding density is ≥95%, and the electromagnetic shielding effectiveness is ≥60dB.

[0032] The aforementioned transmission cable for medical MRI equipment is characterized in that: the inner sheath is made of medical-grade FEP material with a thickness of 1.8±0.10mm.

[0033] The above-mentioned transmission cable for medical MRI equipment is characterized in that: the filling layer is made of high-strength non-magnetic medical degreased cotton yarn.

[0034] The aforementioned transmission cable for medical MRI equipment is characterized in that: both the inner and outer layers are produced using 100% untwisting equipment, and the stranding pitch of the inner and outer layers is controlled to be 8-12 times the outer diameter of each layer.

[0035] The above-mentioned transmission cable for medical MRI equipment is characterized in that: the wrapping layer is made of double-layered overlapping non-magnetic non-woven fabric with an overlap rate of ≥25%.

[0036] The aforementioned transmission cable for medical MRI equipment is characterized in that: the outer sheath is made of medical-grade sterile and wear-resistant polyurethane material or medical-grade material.

[0037] This invention is a dedicated all-magnetic-free integrated transmission cable for medical MRI equipment. The overall structure is a coaxial circular layered symmetrical structure, consisting of 16-core RG178 coaxial cable, cotton yarn filling layer, inner braided shielding layer, non-woven fabric wrapping layer, and outer sheath from the inside out. The coaxial cable serves as the core transmission core group. All 16 core inner sheaths are RG178 coaxial cables. This coaxial cable is a medical-grade all-magnetic-free design, fully adaptable to the strong magnetic field environment and high-precision signal transmission requirements of MRI equipment.

[0038] This invention has the following characteristics: 1. All 16 core inner sheaths use RG178 coaxial cables. These coaxial cables have a completely non-magnetic structure, which fully meets the non-magnetic compatibility requirements of strong magnetic fields in medical MRI equipment. Their structure, from the inside out, consists of a conductor, an insulating layer, a braided shielding layer, and a sheath. The details of each structure are as follows.

[0039] 1.1 Conductor: The conductors of the RG178 coaxial cable are all silver-plated copper wires, using non-magnetic, high-purity, oxygen-free silver-plated copper wires. Electrolytic silver plating is employed, and continuous annealing is used during the wire drawing process. The wires are formed through a bundled and twisted stranding method (specification 7 / 0.1±0.008mm). The stranding pitch is strictly controlled at 8-12 times the outer diameter of the strand. After stranding, the appearance is uniform and smooth. The entire process is non-magnetic to avoid the introduction of magnetic impurities, resulting in excellent flexibility and bending resistance. It also possesses excellent conductivity, low signal attenuation, high temperature resistance, oxidation resistance, and easy soldering characteristics, perfectly suited for the high-frequency reciprocating bending applications of medical MRI equipment. Furthermore, the non-magnetic nature prevents eddy current heating and magnetic field distortion in strong magnetic fields.

[0040] 1.2 Insulation layer: The insulation layer of the RG178 coaxial cable is made of medical-grade FEP (perfluoroethylene propylene) material with low dielectric constant. The outer diameter is 0.84±0.05mm and the dielectric constant is ≤2.1. It has low signal attenuation and stable transmission phase, which can realize the distortion-free transmission of nuclear magnetic resonance radio frequency echo signals and gradient control signals, ensuring imaging accuracy and equipment control accuracy. At the same time, it has excellent resistance to high and low temperatures and chemical corrosion, making it suitable for medical sterilization scenarios.

[0041] 1.3 Braided Shielding Layer: The RG178 coaxial cable is equipped with a non-magnetic silver-plated copper wire braided shielding layer, which is made of 16×3 / 0.1±0.008mm silver-plated copper wire with a braiding density of ≥95% and an electromagnetic shielding effectiveness of ≥60dB. It resists external electromagnetic interference, suppresses internal signal crosstalk, further improves the anti-electromagnetic interference capability, and avoids interfering with the magnetic field uniformity of the nuclear magnetic resonance equipment.

[0042] 1.4 Sheath (RG178 Coaxial Cable Sheath): Made of medical-grade FEP (perfluoroethylene propylene) material with a thickness of 1.8±0.10mm, it completely covers the internal conductor, insulation layer, and braided shielding layer of the coaxial cable. FEP material has excellent resistance to high and low temperatures (operating temperature range -55℃~200℃), chemical corrosion resistance, and sterilization resistance. At the same time, it has excellent insulation performance, which plays a role in fixing the structure and isolating and protecting it, preventing displacement and damage to the internal structure of the coaxial cable during bending, and further improving the insulation and isolation effect, meeting medical-grade safety standards.

[0043] 1.5 The 16-core RG178 coaxial cable is symmetrically arranged according to the cross-sectional view. It is divided into radio frequency signal transmission core wires, gradient power supply core wires, and control and sensing core wires according to the differences in transmission functions. All of them adopt the above unified RG178 coaxial cable structure. They can have the same structure, or only the cabling pitch of the inner and outer layers can be finely adjusted according to the transmission requirements as needed, ensuring the performance requirements for adapting to different signal transmission scenarios, while ensuring the structural consistency and batch stability of the 16-core structure.

[0044] 2. The cotton yarn filling layer fills all the gaps between multiple groups of core wires. High-strength non-magnetic medical degreased cotton yarn is used, and the filling is full and dense, ensuring the overall roundness of the cable, avoiding the internal core wires from moving and rubbing against each other during the bending process of the cable, further improving the structural stability and bending resistance performance. At the same time, the non-magnetic material will not interfere with the magnetic field environment of the nuclear magnetic resonance equipment.

[0045] 3. The cable is produced by a 100% untwisting equipment during cabling. The stranding pitch is strictly controlled within 8 - 12 times of the stranding outer diameter, greatly reducing the stress of the cable itself and extending the service life of the cable.

[0046] 4. The non-woven fabric wrapping layer is wrapped outside the inner sheath. Double-layer overlapping non-magnetic non-woven fabric is used, with an overlapping rate ≥ 25%. The wrapping is flat and tight, without problems such as missing wrapping and wrinkling, playing a role in structural isolation and buffer protection. At the same time, it ensures the flatness of the outer sheath coating, improving the appearance consistency and structural stability of the cable.

[0047] 5. The outer sheath is extruded on the outermost layer of the entire cable. Medical-grade sterilization-resistant and wear-resistant polyurethane (PUR) material is used, or it can be replaced with medical-grade material according to the usage scenario; the material has no cytotoxicity, no skin irritation, no sensitization reaction, and has excellent chemical disinfection resistance, oil resistance, and wear resistance. At the same time, it has good elasticity and strong weather resistance, can adapt to the long-term working environment of -40°C to 80°C, and its performance has no obvious attenuation after multiple high-temperature and high-pressure sterilizations. The color categories are rich and can be adapted to customized solutions.

[0048] The applicant tested the fatigue-resistant control cable with the model specification of: 16C×30AWG(7 / 0.102SP)(RG178), product number: DO6871A0900, voltage temperature: 300V / 105°C, and product name: fatigue-resistant control cable. All the coaxial cable shapes and structures are exactly the same, and the test conclusion is all qualified. The specific test data can be seen in Figure 2 。

[0049] The present invention has the following main beneficial technical effects: 1. The entire structure is designed to be non-magnetic. All conductors are made of silver-plated copper wire, and the shielding and filling materials are all made of non-magnetic materials and non-magnetic processing technology. There is no eddy current heating or magnetic field distortion in a strong magnetic field environment. It is fully compatible with mainstream medical MRI equipment of 1.5T, 3.0T and above, eliminating the safety hazards of magnetic field interference and thermal damage from the source.

[0050] 2. High-coverage non-magnetic braided shielding structure with electromagnetic shielding effectiveness ≥60dB can effectively resist the complex electromagnetic environment interference of strong magnetic fields and high-frequency radio frequency pulses of MRI equipment, while eliminating internal signal crosstalk, ensuring high-fidelity transmission of weak MRI echo signals, greatly improving image clarity, eliminating artifact problems, and supporting accurate clinical diagnosis.

[0051] 3.16 The inner sheath of each core is an RG178 coaxial cable. This coaxial cable integrates conductor, insulation, shielding, and sheath structure, and is equipped with a medical-grade outer sheath, providing a full-process medical-grade safety design. The sheath of the RG178 coaxial cable itself is made of FEP material, which has excellent sterilization resistance and high and low temperature resistance, providing double protection for safety and durability in clinical contact use. At the same time, the standardized structure of the RG178 coaxial cable improves the consistency of product batches.

[0052] 4. Excellent sterilization resistance and environmental tolerance: The 16-core RG178 coaxial cable's FEP sheath, combined with the cable's outer PUR sheath, can withstand dozens of sterilization treatments using high temperature, high pressure, ethylene oxide, and other methods without aging, cracking, or performance degradation. Furthermore, the RG178 coaxial cable can adapt to working environments from -55℃ to 200℃, exhibiting excellent resistance to chemical disinfection, abrasion, and high and low temperatures, making it suitable for the stringent infection control and usage requirements of medical settings.

[0053] The 5.16-core RG178 coaxial cable (with silver-plated copper wire conductor) combined with a symmetrical cabling structure and multi-layer flexible protection design has excellent bending and fatigue resistance. The RG178 coaxial cable itself has excellent flexibility, and with cotton yarn filling and double shielding structure, it has a reciprocating bending life of ≥600,000 times without core breakage. It is perfectly adapted to the application scenarios of high-frequency reciprocating movement of nuclear magnetic resonance beds and frequent coil insertion and removal, which greatly extends the service life of the cable.

[0054] 6. The structure is reasonably designed, the cabling process is stable, the batch products are highly consistent, and the number of core wires, sheath materials, and shielding structures can all be customized according to different field strengths and different models of NMR equipment, with strong versatility and expandability.

[0055] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A transmission cable for medical MRI equipment, comprising sixteen coaxial cables, a filler layer (5), a wrapping layer (6), and an outer sheath (7), characterized in that: The coaxial cable consists of a conductor (1), an insulation layer (2), an inner braided shielding layer (3), and an inner sheath (4). The insulation layer covers the conductor, the inner braided shielding layer covers the insulation layer, and the inner sheath covers the inner braided shielding layer. The inner layer has five coaxial cables, and the axes of all the coaxial cables in the inner layer are evenly distributed on the first circumference. Adjacent coaxial cables in the inner layer are externally tangent. The outer layer has eleven coaxial cables, and the axes of all the coaxial cables in the outer layer are evenly distributed on the second circumference. Adjacent coaxial cables in the outer layer are externally tangent. The outer layer is located outside the inner layer. The filling layer fills all the gaps inside the outer layer, or the filling layer fills all the gaps inside the wrapping layer. The transmission cable as a whole has a coaxial circular layered symmetrical structure.

2. The transmission cable for medical MRI equipment according to claim 1, characterized in that: The conductors are all non-magnetic, high-purity, oxygen-free silver-plated copper wires, which are electrolytically silver-plated, continuously annealed during the wire drawing process, and formed by stranding the wires together. The stranding pitch is 8-12 times the outer diameter of the strand.

3. The transmission cable for medical MRI equipment according to claim 1, characterized in that: The insulation layer is made of medical-grade FEP material with low dielectric constant. The outer diameter of the insulation layer is 0.84±0.05mm and the dielectric constant is ≤2.

1.

4. The transmission cable for medical MRI equipment according to claim 1, characterized in that: The braided shielding layer is made of 16×3 / 0.1±0.008mm silver-plated copper wire, with a braiding density of ≥95% and an electromagnetic shielding effectiveness of ≥60dB.

5. The transmission cable for medical MRI equipment according to claim 1, characterized in that: The inner sheath is made of medical-grade FEP material with a thickness of 1.8±0.10mm.

6. The transmission cable for medical MRI equipment according to claim 1, characterized in that: The filling layer is made of high-strength, non-magnetic medical degreased cotton yarn.

7. The transmission cable for medical MRI equipment according to claim 1, characterized in that: The wrapping layer uses double-layered, overlapping, non-magnetic non-woven fabric with an overlap rate of ≥25%.

8. The transmission cable for medical MRI equipment according to claim 1, characterized in that: The outer sheath is made of medical-grade sterile and wear-resistant polyurethane material or medical-grade material.

9. A transmission cable for medical MRI equipment according to claim 1, characterized in that: Both the inner and outer layers of cabling are produced using 100% de-twisting equipment.

10. A transmission cable for medical MRI equipment according to claim 9, characterized in that: The stranding pitch of the inner and outer layers of cabling is controlled at 8-12 times the outer diameter of each layer.

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