High-torsion-control soft-head ultra-smooth distance-measuring urinary mixed guide wire

Abstract

The utility model relates to the technical field of medical equipment, in particular to a high-torsion-control soft-head ultra-smooth distance-measuring urinary mixed guide wire, an inner core of the guide wire is in a polygonal oval shape, the inner core of a soft head part is ground and processed into a polygonal oval gradually-changed slender inner core, and the farthest side end is in a flat polygonal oval slender shape. The top end is welded into a round ball head through plasma, a multilateral oval coil and a far-side multilateral oval coil are wound on an inner core of the guide wire soft head portion, the guide wire soft head portion and the guide-in section plastic-coated sleeve are made of polyurethane materials coated with hydrophilic coatings and consistent in color, the color of the guide wire soft head portion and the guide-in section plastic-coated sleeve is obviously different from that of the handheld operation section, and the handheld operation section plastic-coated sleeve is made of hydrophobic polytetrafluoroethylene. A positioning ranging ring or a ranging section is provided. According to the guide wire, the head flexibility, the tracking performance and the twisting control performance of the guide wire can be improved, the high lubricity of the soft head and the leading-in section is kept, it is guaranteed that the handheld operation section is easy to hold and operate, the guide wire can smoothly pass through a narrow obstructive diseased region, a user is accurately assisted in ranging under endoscope direct vision, and treatment is more accurate.

Description

Technical Field

[0001] The utility model relates to the technical field of medical equipment, and more specifically, to a high-torsion-controllable, soft-head, ultra-slip, and distance-measuring hybrid guidewire for urology. Background Art

[0002] A guidewire is a surgical medical device that can enter the target cavity and provide support and guidance. The performance of a guidewire is primarily evaluated by indicators such as tip hardness, flexibility, torque control, pushability, and support force. The inner core of a guidewire is its most basic structure, and its structure and material are important factors that influence and determine its support force, controllability, tracking, and torque transmission. Generally speaking, the thicker the diameter of the guidewire inner core, the higher its hardness, the greater its support force, the better its torque transmission, and the stronger its pushability. The opposite is true for a thinner core diameter, which results in increased flexibility and better tracking of the guidewire.

[0003] The tapering section (soft head) of the soft head of the inner core of the guidewire is shorter, thinner, with a large slope and an unclear transition section. Although the support force of the guidewire is good, its flexibility is reduced and its controllability is poor. If the tapering section (soft head) of the soft head of the inner core of the guidewire is long, thinner, and the transition is smooth, although the support force of the guidewire is reduced, the controllability and tracking of the head are enhanced, which is conducive to smoothly passing through the twisted ureter and the narrow part of the stone obstruction. Especially when the stone is impacted at the ureteral opening, the softness and twist control of the guidewire head can increase the chance of the guidewire passing through the narrow lesion, and it is not easy to form a false passage or even tissue damage.

[0004] During flexible ureteroscopy, the ureteral introducer sheath can be gradually introduced into the ureter along the guidewire until it is placed at the ureteropelvic junction. Currently, most researchers choose to first use an F8 rigid ureteroscope to explore the ureter along the guidewire to understand the thickness of the ureter and roughly estimate the length of the ureteropelvic junction and the external urethral opening. They then use experience and feel to roughly estimate the depth of the flexible ureteroscopic sheath insertion, which can be a rough estimate.

[0005] At the end of flexible ureteroscopy and rigid ureteroscopy, a ureteral stent needs to be placed. Since the length of the ureter is usually different for different patients, if the length of the selected ureteral stent is too long, the J-shaped head of the ureteral stent will be too long when it is inserted into the bladder after implantation. Especially when it exceeds the midline of the bladder, it is easy to irritate the bladder mucosa, causing the patient to have hematuria, frequent urination, urgency and pain when urinating. The currently available zebra guidewires and loach guidewires cannot measure the length of the patient's ureter in conjunction with common surgical equipment. In addition, the loach guidewire is too slippery to be held and fixed. Although the zebra guidewire is easy to hold and operate due to its hydrophobicity, the lubricity of the introduction part is insufficient, which needs to be solved urgently.

[0006] An existing urinary tract guidewire, with publication number CN 219804123 U, comprises a core wire, a wire wrap, and a tip. The tip has a spherical opening at its head end, and its mid- and tail sections have high-hardness, heat-treated threads. The tail section of the tip is welded to the proximal end of the core wire. The proximal surface of the core wire is wrapped with a wire wrap. The mid- and distal surfaces of the core wire are coated with PTFE. The wire wrap is coated with a hydrophilic coating. The distal end of the core wire is connected to a catheter. This guidewire reduces the risk of breakage during use, but suffers from poor torque control and inability to measure distance. While maintaining a balanced performance, it still suffers from some limitations. Summary of the Invention

[0007] In order to overcome the above-mentioned defects of the prior art, the purpose of the present invention is to provide a highly torque-controlled, soft-headed, ultra-smooth, and measurable hybrid guidewire for urology, which can improve the torque control operation of the distal end of the guidewire while maintaining the flexibility and tracking performance of the guidewire head, making the treatment more precise.

[0008] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a high-torque control soft-head ultra-smooth and measurable hybrid guide wire for urology, comprising a core wire and a plastic-coated sleeve, the plastic-coated sleeve being wrapped around the outside of the core wire, the core wire comprising a core wire soft head and a core wire body, the core wire body being a polygonal ellipse, the core wire soft head being a gradient polygonal ellipse stepped slender type or a gradient streamlined polygonal ellipse slender type, the farthest end of the core wire soft head being a polygonal ellipse flat slender type, the top of the core wire soft head being provided with a plasma-welded circular ball head, the outside of the core wire soft head being provided with a proximal coil and a distal coil, the plastic-coated sleeve being divided into a plastic-coated soft head, an introduction part and a handheld operating part, the plastic-coated soft head and the introduction part being polymers with a hydrophilic coating, the handheld operating part being a hydrophobic polymer, and the handheld operating part being provided with a positioning and ranging ring or ranging segments of different colors.

[0009] Preferably, the core wire soft head is a polygonal elliptical core wire body that is ground into a gradient polygonal elliptical stepped slender shape, the farthest end of the core wire soft head is a polygonal elliptical flat slender shape, a plasma-welded circular ball head is provided on the top of the core wire soft head, the circular ball head is slightly larger than the core wire, a proximal coil and a distal coil are provided outside the core wire soft head, and a plastic-coated soft head of a hydrophilic coating polymer developed with tungsten powder is provided outside the core wire soft head.

[0010] Preferably, the proximal coil and the distal coil are made of platinum-tungsten alloy, nickel-titanium alloy or stainless steel, and the metal wire size of the distal coil is smaller than the metal wire size of the proximal coil.

[0011] Preferably, the core wire soft head is a polygonal elliptical core wire body that is ground into a gradient polygonal elliptical streamlined slender type, and the guide wire core wire body is a polygonal elliptical streamlined slender type with a gradually tapering diameter from the proximal end to the core wire soft head, and its distalmost section is a flat polygonal elliptical slender type. The core wire soft head is wrapped with a polygonal elliptical coil, and a plasma-welded circular ball head is provided on the top of the core wire soft head.

[0012] Preferably, the plastic-coated sleeve is divided into a plastic-coated soft head, an introduction part and a handheld operating part. The handheld operating part is arranged at the proximal end, one side of the handheld operating part is connected to the introduction part, and the introduction part is connected to the plastic-coated soft head. The plastic-coated soft head and the introduction part are made of a polyurethane material with a hydrophilic coating of the same color, and the handheld operating part is made of a hydrophobic polytetrafluoroethylene material that is different from the color of the plastic-coated soft head and the introduction part.

[0013] Preferably, the handheld operating unit is provided with a positioning distance measuring ring or distance measuring segments of different colors, and the distance measuring segments include narrow scale lines and wide scale lines.

[0014] Preferably, the core wire is an inner core with a diameter gradually tapering from near to far, and the outer diameter of the core wire after being wrapped with the plastic sleeve is consistent.

[0015] Preferably, the core wire is an inner core with a diameter gradually tapering from near to far, and after the core wire is wrapped with the plastic sheath, the outer diameter of the guide wire from the proximal end to the distal end gradually tapers from near to far.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1. The core wire of the hybrid guidewire for urology with high torque control, soft tip, ultra-smooth and measurable range is the most basic structure of the present invention. The structure and material of the core wire are important factors affecting and determining the guidewire's supporting force, controllability, tracking, and torque transmission. The core wire is divided into a core wire soft head and a core wire body. The cross-section of the core wire body is a polygonal ellipse. The inner core of the core wire soft head is ground into a polygonal ellipse with gradual steps and elongated shape. The distal end can be a flat polygonal ellipse with elongated shape. The top is plasma welded into a round ball head. The proximal and distal steps are wrapped with metal wire. The wire size of the distal coil is thinner and more flexible than that of the proximal coil, and the distal coil is not connected to the proximal coil. The hydrophilic coating polymer developed by tungsten powder is formed on the outside of the structure to form the soft head section of the guidewire. Without increasing the branch diameter of the guidewire, the flexibility and tracking of the distal end of the guidewire can be improved, and the torque control operation can be improved, making the treatment more precise.

[0018] 2. The utility model is a hybrid guidewire for urology with a high torque controllability, a soft tip, an ultra-smooth and rangeable design. The core wire body is a polygonal elliptical streamlined elongated shape with a gradually tapering diameter from the proximal end to the core wire soft tip. The core wire soft tip is partially wrapped with a polygonal elliptical coil, and its distalmost section is a flat polygonal elliptical elongated shape. The top of the core wire soft tip is provided with a plasma-welded round ball head. After the core wire is wrapped with a plastic sheath, the outer diameter of the guidewire gradually tapers from the proximal end to the distal end, which can improve the flexibility, tracking and torque control of the distal end of the guidewire. At the same time, when the guidewire is rotated, the guidewire head rotates mostly in the directions on both sides of the polygon, making the directional controllability of the guidewire head better when using guidewire torque.

[0019] 3. The utility model is a high-torque controllable soft-headed, ultra-smooth and measurable hybrid guidewire for urology. The core wire soft head and the plastic-coated introduction part are provided with a polymer covered with a highly lubricating hydrophilic coating. The plastic-coated sheath of the handheld operation part is hydrophobic polytetrafluoroethylene, which can not only maintain the lubricity of the guidewire soft head and the distal introduction part, but also maintain the advantage of easy hand-held operation of the proximal handheld operation part, and can pass through the narrow lesion relatively smoothly. The soft head, the introduction part and the handheld operation part have obvious color differences, and the handheld operation part has a ranging ring for distinguishing the distance. It can accurately assist the user to measure the distance according to the color difference of the soft head, the introduction part and the handheld operation part and the ranging ring on the handheld operation section under direct endoscopic vision, measure the depth of the guidewire entry and measure the length of the implant to be selected. For example, in ureteroscopy, the length from the renal pelvis to the urethral orifice can be measured to roughly judge the approximate implantation depth of the ureteroscope guide sheath. The approximate length of the ureter is measured during the operation to select a ureteral stent of appropriate length, making the treatment more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the core wire structure of the first embodiment of a hybrid guidewire for urology with a high torque control, soft head, ultra-slip and measurable distance according to the present invention;

[0021] Figure 2 This is a schematic diagram of the plastic sheath structure of a hybrid guidewire for urology with a high-torque controllable soft tip and super-slip distance measurement in the utility model;

[0022] Figure 3 This is a structural diagram of a first embodiment of a hybrid guidewire for urology with a high torque controllable soft tip and super smoothness and measurable distance according to the present invention;

[0023] Figure 4 This is a cross-sectional view of the core wire of a hybrid guidewire for urology with a high-torque control, soft head, ultra-smooth and measurable distance.

[0024] Figure 5 This is a structural diagram of a second embodiment of the utility model of a hybrid guidewire for urology with a high torque controllable soft tip and ultra-slip distance measurement;

[0025] Figure 6This is a schematic diagram of the structure of a high-torque-controllable, soft-tip, ultra-slip, and distance-measuring hybrid guidewire for urology in use;

[0026] In the figure: 1-core wire, 2-plastic-coated sleeve, 3-core wire soft head, 4-guide wire body, 5-round ball head, 6-proximal coil, 7-distal coil, 8-plastic-coated soft head, 9-introduction part, 10-handheld operation part, 101-narrow scale line, 102-wide scale line. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0028] Example 1

[0029] See Figure 1-4In the embodiment of the present invention, a high-torque control soft-head ultra-smooth and rangeable hybrid guidewire for urology includes a core wire 1 and a plastic sheath 2, the plastic sheath 2 is wrapped around the outside of the core wire 1, the core wire 1 includes a core wire soft head 3 and a core wire body 4, the cross-section of the core wire body 4 is a polygonal ellipse, the core wire soft head 3 is a gradient polygonal ellipse step-shaped slender type, the farthest end of the core wire soft head 3 is a polygonal ellipse flat slender type, the top of the core wire soft head 3 is provided with a plasma-welded circular ball head 5, the circular ball head 5 is slightly larger than the core wire, and the core wire soft head 3 is provided with a proximal coil 6 and distal coil 7, the core wire soft head 3 is provided with a plastic-coated soft head 8 of a hydrophilic coating polymer containing tungsten powder development, the core wire soft head 3 is provided with a proximal coil 6 and a distal coil 7, the proximal coil 6 and the distal coil 7 are made of platinum-tungsten alloy, nickel-titanium alloy or stainless steel, the metal wire size of the distal coil 7 is smaller than the metal wire size of the proximal coil 6, the plastic-coated sleeve 2 is divided into a plastic-coated soft head 8, an introduction part 9 and a handheld operation part 10, the plastic-coated soft head 8 and the introduction part 9 are polymers with a hydrophilic coating, the plastic-coated soft head 8 is 8 to 15 cm long, preferably 10c m, the length of the introduction part 9 is 20 to 30 cm, preferably 25 cm, the handheld operation part 10 is a hydrophobic polymer, the plastic-coated soft head 8 and the introduction part 9 are made of polyurethane material with a hydrophilic coating of the same color, such as black to white, red, blue, etc. or black to two colors, such as the guide wire soft head and the distal introduction section plastic cover is black, the proximal handheld operation section plastic cover is white, red, yellow, etc., or the guide wire soft head and the distal introduction section plastic cover is black loach guide wire shape, the proximal handheld operation section plastic cover is black / white or yellow / black zebra shape, the handheld The operating portion 10 is made of a hydrophobic polytetrafluoroethylene material that is different in color from the plastic-coated soft head 8 and the introduction portion 9. The handheld operating portion 10 is provided with a positioning and ranging ring or a differently colored ranging segment. The ranging segment includes a narrow scale line 101 and a wide scale line 102. The positioning ring is positioned 1 to 10 cm from the clearly colored connection between the proximal handheld operating segment and the distal introduction segment, preferably 5 cm, with each positioning segment spaced 10 cm apart. The positioning rings are distinguished by number, thickness, or color, with ranging scale lines spaced 1 to 3 cm apart, preferably 2 cm apart, between adjacent positioning rings. After the core wire 1 is wrapped with the plastic-coated sheath 2, the outer diameters of the proximal and distal ends of the guidewire are the same.

[0030] Example 2

[0031] See Figure 5 、 6In the embodiment of the present invention, a high-torque control soft head ultra-smooth and range-measuring hybrid guidewire for urology is provided. The guidewire core wire 1 is made of stainless steel or nickel-titanium alloy, and the core wire 1 is a polygonal elliptical shape. The core wire soft head 3 is a polygonal elliptical shape. The core wire body 4 is ground into a gradient polygonal elliptical streamlined and slender shape, and the guidewire core wire body 4 is a polygonal elliptical streamlined and slender shape with a gradually tapering diameter from the proximal end to the core wire soft head 3. The distal end thereof is a flat polygonal elliptical and slender shape. The core wire soft head 3 is wrapped with a polygonal elliptical coil, and a plasma-welded round ball head 5 is provided on the top of the core wire soft head 3. The core wire soft head 3 is composed of multiple The outer surface of the inner core is elliptical and gradually elongated, and the outer surface of the inner core contains a hydrophilic coating polymer developed by tungsten powder. The length of the core wire soft head 3 is 5 to 30 cm, preferably 8 to 12 cm. The core wire soft head 3 can be straight or curved. The core wire soft head 3 and the plastic-wrapped introduction part 9 are made of polyurethane with a hydrophilic coating. The plastic-wrapped cover of the handheld operating part 10 is hydrophobic polytetrafluoroethylene. The core wire soft head 3, the introduction part 9 and the handheld operating part 10 are obviously different in color. There is a ranging ring or ranging segments of different colors on the handheld operating part 10. After the core wire 1 is wrapped with the plastic-wrapped cover 2, the outer diameters of the proximal and distal ends of the guide wire are consistent, and the rest is the same as in Example 1.

[0032] Example 3

[0033] After the core wire 1 is wrapped with the plastic sheath 2, the outer diameter of the guide wire from the proximal end to the distal end gradually becomes thinner from near to far, forming a loach zebra hybrid guide wire with good head flexibility and tracking performance, which can be used for distance measurement under direct vision, and the rest is the same as Example 2.

[0034] Example 4

[0035] The guide wire core wire 1 is made of a combination of stainless steel and nickel-titanium alloy, wherein the core wire soft head 3 is nickel-titanium alloy and the guide wire body 4 is stainless steel, which are welded to form a core wire 1 of two different materials, and the rest is the same as in Examples 1 to 3.

[0036] Working principle:

[0037] The utility model discloses a high-torque control soft head ultra-smooth and measurable hybrid guide wire for urology. When the guide wire is passed through the ureteroscope into the ureteral opening, especially when there is a ureteral stone tightly embedded in the ureteral opening, the front end of the ureteroscope must be brought as close as possible, and the assistant is asked to increase the pressure to inject water. Since the core wire 1 of the guide wire is a polygonal ellipse, the soft head 3 of the core wire is ground into a polygonal ellipse with gradual steps and elongated shape. The distal end is a flat polygonal ellipse with a slender shape. The top end is plasma welded into a round ball head 5. The proximal step and the distal step are wrapped with metal wire to form a The proximal coil 6 and the distal coil 7 are made of a hydrophilic coating polymer with tungsten powder as the outer surface, so the core wire soft head 3 has excellent flexibility and tracking properties, and the torque transmission effect at the distal end is good. The material of the plastic-coated soft head 8 and the introduction section 9 is a polyurethane material with a hydrophilic coating, and the handheld operating part 10 is hydrophobic polytetrafluoroethylene, which can not only maintain the lubricity of the plastic-coated soft head 8 and the introduction section 9, but also ensure the advantage of easy handheld operation of the handheld operating part 10. It can smoothly pass through the ureteral stone and be tightly embedded in the ureteral opening, and is not easy to form a false passage, thereby reducing the difficulty of treatment.

[0038] When performing ureteroscopy, it is necessary to measure the depth of the ureteroscope sheath inserted from the urethral opening, or to measure the length of the ureter after treating stones, so as to select a ureteral stent of reasonable length, the length of the plastic-coated soft head 8 is about 8 to 12 cm, and the length of the introduction part 9 is about 25 to 30 cm. The colors of the plastic-coated soft head 8, the introduction part 9 and the hand-held operation part 10 are obviously different. For example, the plastic-coated soft head 8 and the introduction part 9 are black, and the proximal hand-held operation part 10 is white, red, yellow, etc., or the plastic-coated soft head 8 and the introduction part 9 are black loach-shaped, and the hand-held operation part 10 is black / white or yellow / black. The handheld operating part 10 is zebra-shaped, with a ranging ring or ranging segments of different colors. The positioning ring is set about 5 cm from the connection between the handheld operating part 10 and the introduction part 9, which is clearly distinguished by color. The spacing between each positioning ring is 10 cm. The positioning rings are distinguished by the number of rings, thickness or color. There is a ranging scale line with a spacing of 2 cm between two adjacent positioning rings. Since the approximate length from the ureter to the renal pelvis is 26 cm, it can be clearly seen under the ureteroscope whether the introduction part 9 has completely entered the ureteral opening, and then the distance is accurately measured through the ranging ring on the handheld operating part 10, making the treatment more accurate.

[0039] The above embodiments are intended to illustrate the present invention, not to limit the present invention. Any solution that is a simple transformation of the present invention falls within the scope of protection of the present invention.

Claims

1. A highly torque-controlled, soft-tip, ultra-smooth, and measurable hybrid guidewire for urology, characterized by: The invention comprises a core wire (1) and a plastic sheath (2), wherein the plastic sheath (2) is wrapped around the outside of the core wire (1), and the core wire (1) comprises a core wire soft head (3) and a core wire body (4), wherein the cross section of the core wire body (4) is a polygonal ellipse, the core wire soft head (3) is a gradient polygonal ellipse step slender type or a gradient streamline polygonal ellipse slender type, the distal end of the core wire soft head (3) is a polygonal ellipse flat slender type, the top of the core wire soft head (3) is provided with a plasma-welded circular ball head (5), the core wire soft head (3) is provided with a proximal coil (6) and a distal coil (7), the plastic sheath (2) is divided into a plastic sheath soft head (8), an introduction part (9) and a handheld operation part (10), the plastic sheath soft head (8) and the introduction part (9) are polymers with a hydrophilic coating, the handheld operation part (10) is a hydrophobic polymer, and the handheld operation part (10) is provided with a positioning distance measuring ring or distance measuring segments of different colors.

2. The high-torque-controllable, soft-tip, ultra-smooth, and measurable hybrid guidewire for urology according to claim 1, characterized in that: The proximal coil (6) and the distal coil (7) are made of platinum-tungsten alloy, nickel-titanium alloy or stainless steel, and the metal wire size of the distal coil (7) is smaller than the metal wire size of the proximal coil (6).

3. The high-torque-controllable, soft-tip, ultra-smooth, and measurable hybrid guidewire for urology according to claim 1, characterized in that: The core wire soft head (3) is a polygonal elliptical core wire body (4) ground into a gradient polygonal elliptical streamlined slender type, and the guide wire core wire body (4) is a polygonal elliptical streamlined slender type with a gradually tapering diameter from the proximal end to the core wire soft head (3), and its most distal section is a flat polygonal elliptical slender type. The core wire soft head (3) is wound with a polygonal elliptical coil, and a plasma-welded circular ball head (5) is provided at the top of the core wire soft head (3).

4. The high-torque-controllable, soft-tip, ultra-smooth, and measurable hybrid guidewire for urology according to claim 1, characterized in that: The plastic-coated sleeve (2) is divided into a plastic-coated soft head (8), an introduction part (9) and a handheld operating part (10). The handheld operating part (10) is arranged at the proximal end, and one side of the handheld operating part (10) is connected to the introduction part (9). The introduction part (9) is connected to the plastic-coated soft head (8). The plastic-coated soft head (8) and the introduction part (9) are made of a polyurethane material with a hydrophilic coating of the same color. The handheld operating part (10) is made of a hydrophobic polytetrafluoroethylene material that is different in color from the plastic-coated soft head (8) and the introduction part (9).

5. The high-torque-controllable, soft-tip, ultra-smooth, and measurable hybrid guidewire for urology according to claim 4, characterized in that: The handheld operating unit (10) is provided with a positioning distance measuring ring or distance measuring segments of different colors, and the distance measuring segments include narrow scale lines (101) and wide scale lines (102).

6. The high-torque-controllable, soft-tip, ultra-smooth, and measurable hybrid guidewire for urology according to claim 1, characterized in that: The core wire (1) is an inner core with a gradually tapering diameter from near to far, and the outer diameter of the core wire (1) after being wrapped with the plastic sheath (2) is consistent.

7. The high-torque-controllable, soft-tip, ultra-smooth, and measurable hybrid guidewire for urology according to claim 1, characterized in that: The core wire (1) is an inner core with a diameter gradually tapering from near to far. After the core wire (1) is wrapped with the plastic sheath (2), the outer diameter of the guide wire from the proximal end to the distal end gradually tapers from near to far.

8. The high-torque-controllable, soft-tip, ultra-smooth, and measurable hybrid guidewire for urology according to claim 1, characterized in that: The core wire soft head (3) is a polygonal elliptical core wire body (4) ground into a gradient polygonal elliptical stepped slender shape, the distal end of the core wire soft head (3) is a polygonal elliptical flat slender shape, the top of the core wire soft head (3) is provided with a plasma-welded circular ball head (5), the circular ball head (5) is slightly larger than the core wire, the core wire soft head (3) is provided with a proximal coil (6) and a distal coil (7), and the core wire soft head (3) is provided with a plastic-coated soft head (8) of a hydrophilic coating polymer containing tungsten powder development.

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