Needle tip shielded indwelling needle and method of making same

Abstract

The application relates to an indwelling needle with needle tip protection, which relates to the field of indwelling needles and comprises a three-way joint, a connecting conduit, a sleeve seat, a needle handle, a hemostatic sealing plug, a puncture needle tube, a needle straightener, a sleeve and a sheath. The front end of the sleeve seat is provided with a sleeve connecting hole, and the rear side of the sleeve connecting hole is provided with an installation cavity with an open rear end in the sleeve seat. The rear part of the sleeve is inserted into the sleeve connecting hole, the connecting conduit is communicated with the installation cavity through an injection joint, the installation cavity between the hemostatic sealing plug and the needle handle is provided with a protective cap, the protective cap is sleeved on the puncture needle tube and can slide axially along the puncture needle tube, a pulling line is arranged between the rear end of the protective cap and the needle handle, the length of the pulling line is smaller than the length of the puncture needle tube on the front side of the needle handle, and the sum of the length of the pulling line and the thickness of the protective cap is not smaller than the length of the puncture needle tube on the front side of the needle handle. The indwelling needle with needle tip protection has the advantages of simple structure, low cost, same appearance as the commonly used Y-shaped indwelling needle, unchanged operation method during use, simple operation and the like.

Description

Technical Field

[0001] The present invention relates to the field of indwelling needles, in particular to a needle tip protection indwelling needle with a simple structure, low cost, the same appearance as a commonly used Y-shaped indwelling needle, the same operation method when in use, and simple operation, and a preparation method thereof. Background Art

[0002] As an emerging infusion tool, catheterization has been widely used in clinical practice over the past decade. Especially for hospitalized patients, it has largely replaced the original method of infusion through an infusion device. Its characteristic is that after a plastic soft cannula is inserted into the human vein through a steel needle puncture, the puncture needle is pulled out and the cannula is left in the human body. The next time the infusion is done, it can be directly connected to the infusion device through the cannula left in the human body without puncture. This shows its advantages: for patients, it can reduce the pain caused by multiple punctures, and for medical staff, it can greatly reduce the workload. Therefore, catheterization has been generally recognized by doctors and patients, and will continue to exist for a long time in the future.

[0003] At present, the most commonly used indwelling needle in clinical practice is the Y-type indwelling needle, which includes a three-way connector, a connecting catheter, a cannula seat, a needle handle, a hemostatic sealing plug, a puncture needle tube, a needle straightener, a cannula and a sheath. The front end of the cannula seat is provided with a cannula connecting hole, and the cannula seat behind the cannula connecting hole is provided with a mounting cavity with a rear end open. The mounting cavity and the cannula connecting hole are connected via a trumpet-shaped needle straightening hole; the rear part of the cannula is inserted into the cannula connecting hole, the needle straightening device is funnel-shaped and has an interference fit with the needle straightening hole, and the front of the needle straightening device is inserted into the rear end of the cannula. The rear end of the cannula is squeezed and fixed in the cannula connecting hole, the puncture needle tube is inserted into the cannula, the front end of the cannula is pointed and in close contact with the puncture needle tube, the hemostatic sealing plug is arranged in the installation cavity on the rear side of the needle straightening device to seal the puncture needle tube and the inner side of the installation cavity, the needle handle cover is arranged at the rear end of the installation cavity, and the rear end of the puncture needle tube is fixedly connected to the needle handle; an injection connector is provided on the cannula seat between the hemostatic sealing plug and the needle straightening device, and the connecting catheter is connected to the installation cavity through the injection connector. A three-way connector is installed at the other end of the connecting catheter, and a heparin cap and a protective cap are installed on the three-way connector.

[0004] The existing production method of this Y-type indwelling needle is as follows: the front part of the needle straightener is inserted into the rear end part of the cannula, the front end of the cannula is passed forward from the opening at the rear end of the mounting cavity through the mounting cavity and placed into the cannula connecting hole, the needle straightener is pressed forward to press the front end of the needle straightener into the cannula connecting hole; the rear end of the puncture needle tube punctures the hemostatic sealing plug and is fixedly connected to the needle handle by dispensing glue; the front end of the puncture needle tube passes through the mounting cavity from the opening at the rear end of the mounting cavity, the needle straightener is placed in the cannula, the hemostatic sealing plug is squeezed into the cannula seat, and the needle handle cover is set on the opening at the rear end of the mounting cavity.

[0005] When the existing Y-shaped indwelling needle puncture needle tube is withdrawn after the puncture is completed, the needle tip is exposed. Due to its sharpness, it is easy to injure others if not handled with care. In recent years, there have been many such cases at home and abroad, especially when patients with infectious diseases infect others. Therefore, clinical practice requires a safety measure to prevent the needle tip from injuring others. In response to this, some manufacturers have produced such products, such as the utility model patent disclosed by the State Intellectual Property Office, entitled "Needle Tube Retractable Indwelling Needle", application number: 201620262783.5, and the utility model patent entitled "A Needle Tube Retractable Indwelling Needle", application number: 201720818622.4. Although these products solve the problem that the needle tip of the puncture needle tube is easy to injure others when it is withdrawn after the puncture is completed, which may cause cross infection, they all have at least one of the following defects: complex structure, high manufacturing cost, significant difference in appearance from commonly used indwelling needles, changed operation method, and increased operation difficulty. The existence of these problems makes it difficult to promote and apply it on a large scale in the market. Summary of the Invention

[0006] The purpose of the present invention is to solve the above-mentioned deficiencies of the prior art and provide a needle tip protection type indwelling needle and its preparation method which has a simple structure, low cost, and the same appearance as the commonly used Y-type indwelling needle, and the same operation method when used and is simple to operate.

[0007] The technical solution of the present invention is:

[0008] A needle tip protection type indwelling needle comprises a three-way connector, a connecting catheter, a cannula seat, a needle handle, a hemostatic sealing plug, a puncture needle tube, a needle straightening device, a cannula and a sheath. The front end of the cannula seat is provided with a cannula connecting hole, and the cannula seat at the rear side of the cannula connecting hole is provided with a mounting cavity with an open rear end. The mounting cavity and the cannula connecting hole are connected via a trumpet-shaped needle straightening hole. The rear part of the cannula is plugged into the cannula connecting hole. The needle straightening device is funnel-shaped and interference-fits with the needle straightening hole. The front part of the needle straightening device is inserted into the rear end of the cannula, and the rear end of the cannula is squeezed and fixed in the cannula connecting hole. The puncture needle tube is inserted into the cannula, and the front end of the cannula is pointed and closely attached to the puncture needle tube. The hemostatic sealing plug is arranged in the mounting cavity at the rear side of the needle straightening device. The needle tube is sealed from the inside of the mounting cavity, a needle handle cover is located at the rear end of the mounting cavity, and the rear end of the puncture needle tube is fixedly connected to the needle handle. An injection connector is provided on the cannula seat between the hemostatic sealing plug and the needle straightening device, through which a connecting catheter communicates with the mounting cavity. A three-way connector is installed at the other end of the connecting catheter, which is fitted with a heparin cap and a protective cap. The device is characterized in that a protective cap is provided in the mounting cavity between the hemostatic sealing plug and the needle handle. The protective cap can be slidably mounted on the puncture needle tube along the axial direction of the puncture needle tube. A traction line is provided between the rear end of the protective cap and the needle handle. The length of the traction line is less than the length of the puncture needle tube at the front of the needle handle, and the sum of the length of the traction line and the thickness of the protective cap is no less than the length of the puncture needle tube at the front of the needle handle. The protective sheath is fixed to the front of the cannula seat and protects the outside of the puncture needle tube and cannula.

[0009] The present invention further improves upon this concept by providing a cylindrical hemostatic sealing plug with an axially extending, radially extending needle insertion notch on one side of the hemostatic sealing plug. The puncture needle is inserted into the center of the hemostatic sealing plug through the notch. The radial dimension of the notch is the sum of the radius of the hemostatic sealing plug and the radius of the puncture needle. The puncture needle can be squeezed into the center of the hemostatic sealing plug through the notch, becoming coaxial with the plug. The connection between the puncture needle and the hemostatic sealing plug does not damage the internal tissue of the plug, resulting in a good sealing effect. When the needle is withdrawn, there is no leakage of blood or fluid. Practical testing has demonstrated that an axial length of 1 mm is sufficient for hemostatic sealing. However, in actual production, for ease of installation and to prevent accidents, the axial length of the hemostatic sealing plug is typically 2-4 mm, preferably 3 mm. Existing hemostatic sealing plugs for Y-type indwelling catheters typically have an axial length of 6 mm. This design saves space within the mounting cavity, providing space for the installation of a protective cap.

[0010] The protective cap of the present invention is in the shape of a bottle cap with an open rear side. A needle tube sliding hole cooperating with the puncture needle tube is provided in the middle of the front side wall of the protective cap. The puncture needle tube can slide freely forward and backward through the needle tube sliding hole.

[0011] The protective cap of the present invention contacts the inner wall of the installation cavity, and the friction force between the protective cap and the inner wall of the installation cavity is 0.1-10N, preferably 0.5-1N.

[0012] A force-disconnecting connector is provided between the front end of the protective cap and the rear end of the hemostatic sealing plug in the present invention. When the tension on the force-disconnecting connector exceeds the connection force, the protective cap and the hemostatic sealing plug are separated. The connection force is 0.1-10N, preferably 0.5-1N.

[0013] The force-bearing separation connector described in the present invention is to set a glue point between the front end of the protective cap and the rear end of the hemostatic sealing plug to partially bond the front end of the protective cap and the rear end of the hemostatic sealing plug; when the tensile separation force between the front end of the protective cap and the rear end of the hemostatic sealing plug is greater than the bonding force, the bonding fails and the protective cap and the hemostatic sealing plug are separated.

[0014] The force-disengaging connector described in the present invention comprises a plug-in connection post on one side of the front end of the protective cap, a socket at the rear end of the hemostatic sealing plug that mates with the plug-in connection post, and an interference fit of the plug-in connection post into the socket. The force generated by the interference fit of the plug-in connection post and the socket acts as the connecting force. When the axial tensile separation force between the protective cap and the hemostatic sealing plug exceeds the force generated by the interference fit of the plug-in connection post and the socket, the two disengage, and the protective cap and hemostatic sealing plug separate.

[0015] The present invention employs a pull line between the rear end of the protective cap and the same side of the needle handle. The force-disengaging connector is located between the protective cap and the hemostatic seal on the side opposite the pull line. As the needle handle pulls the protective cap backward via the pull line, the pull line tilts the cap before it detaches from the hemostatic seal, misaligning the needle tip with the needle slide hole. When the pull line disengages the cap, the needle tip partially inserts into the sidewall of the protective cap, enhancing protection.

[0016] The protective cap of the present invention is provided with a traction line between one side of the rear end of the protective cap and the same side of the needle handle, and an auxiliary line is provided between the rear end of the protective cap and the needle handle on the side opposite the traction line. The length of the auxiliary line is 0.3-3 mm longer than the length of the traction line, preferably 1-2 mm. After the traction line pulls the protective cap to tilt so that the tip of the puncture needle tube is not aligned with the needle tube slide hole, the auxiliary traction line and the traction line jointly pull the protective cap to slide backward within the installation cavity, thereby preventing the protective cap from being excessively deformed by unilateral traction of the traction line, which would lead to unstable friction between the protective cap and the inner wall of the installation cavity, large changes in the relative position between the tip of the puncture needle tube and the protective cap, and even the dangerous situation of the puncture needle tube tip piercing the protective cap.

[0017] The side protective cap of the present invention is made of rubber material and has a certain elasticity, so that the tip of the puncture needle can partially penetrate into the protective cap.

[0018] The axial dimension of the protective cap described in the present invention is 2-8 mm, preferably 3-5 mm; the wall thickness of the protective cap is 0.5-2 mm, preferably 1-1.5 mm; the length of the pull line is 1-3 mm less than the length of the puncture needle tube on the front side of the needle handle, preferably 1.5-2.5 mm; the sum of the length of the pull line and the thickness of the protective cap is greater than the length of the puncture needle tube on the front side of the needle handle, 0.1-3 mm, preferably 0.6-2 mm.

[0019] The tip of the puncture needle tube described in the present invention is located on the opposite side of the pulling line.

[0020] The force-disengaging connector is positioned between the protective cap and the hemostatic seal on the side opposite the pull line. As the needle handle pulls the protective cap backward via the pull line, the pull line tilts the cap before it separates from the hemostatic seal, misaligning the needle tip with the needle slide hole. When the pull line disengages the cap, the needle tip partially inserts into the sidewall of the cap, enhancing protection.

[0021] The traction line described in the present invention is hemp thread, cotton thread or medical suture thread.

[0022] The inner diameter of the protective cap of the present invention is 2-6 times, preferably 3-4 times, the diameter of the needle tube slide hole.

[0023] The present invention further improves the needle handle by providing a needle tube assembly hole on the front side, a glue dispensing hole in the shape of an inverted cone in front of the hole, and radial glue deposit holes connected to the glue dispensing hole on the handle on one side of the hole. For better results, 2-3 radial glue deposit holes evenly distributed around the circumference of the needle tube assembly hole are recommended. Existing needle handles have a needle tube assembly hole on the front side and a glue dispensing hole in the shape of an inverted cone in front of the hole. During assembly, glue is first applied in the glue dispensing hole. After the puncture needle is inserted through the glue dispensing hole into the needle tube assembly hole, glue is primarily deposited in the glue dispensing hole. The connection between the puncture needle and the handle is technically secure, requiring a separation force of at least 30N to prevent the needle from falling into the body when withdrawn after puncture. To ensure this separation force, the inverted cone in the cylindrical portion of the handle must be sufficiently large and deep, meaning it has a long axial depth. Current product pull-out tests have shown that the puncture needle and glue have always been completely separated from the inverted cone-shaped glue dispensing hole. The radial glue deposit holes in this invention prevent dried glue from escaping from the dispensing holes, thus enhancing the connection between the needle and the handle. Product pull-out tests have shown that due to the dispensing holes, the separation force between the needle and the handle exceeds 50N, with most cases involving dried glue separating from the needle. This structure, combined with the required tensile strength of the protective cap, prevents the increased tensile force during needle removal, which could cause the handle to separate from the needle.

[0024] A method for preparing a needle tip protection type indwelling needle comprises the following steps: inserting the front portion of a needle straightener into the rear end portion of a cannula, passing the front end of the cannula from the opening at the rear end of the mounting cavity forward through the mounting cavity and into the cannula connecting hole, pressing the needle straightener forward, and pressing the front end of the needle straightener into the cannula connecting hole; the method is characterized in that the puncture needle tube is inserted into the center of the hemostatic sealing plug through the needle tube insertion groove from one side of the hemostatic sealing plug; the protective cap is sleeved on the puncture needle tube through the rear end of the puncture needle tube; the two ends of the traction line are fixedly connected to the rear end of the protective cap and the needle handle respectively; the rear end of the puncture needle tube and the needle handle are fixedly connected by dispensing glue; the front end of the puncture needle tube is passed through the mounting cavity from the opening at the rear end of the mounting cavity forward, the needle straightener is placed into the cannula, the hemostatic sealing plug and the protective cap are squeezed into the cannula seat together, and the needle handle cover is arranged on the opening at the rear end of the mounting cavity.

[0025] When the present invention is used, all operating techniques are the same as those of the existing Y-type indwelling needle. After the puncture is completed, when the puncture needle tube is pulled out, the traction line is continuously expanded as the needle handle and the puncture needle tube are pulled out. When the needle tip of the puncture needle tube enters the protective cap, the traction line is straightened. When the puncture needle tube is continued to be pulled, the traction line pulls the protective cap backward; when the protective cap is completely separated from the sleeve seat, the traction line pulls the protective cap unilaterally, which will cause the protective cap to shift. After the shift, the hole on the protective cap that matches the puncture needle tube is no longer opposite to the needle tip, and the needle tip cannot be exposed, thereby achieving a protective effect. The present invention has the advantages of simple structure, low cost, the same appearance as the commonly used Y-type indwelling needle, unchanged operating technique during use, and simple operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention.

[0027] Figure 2 yes Figure 1 A partial enlarged view of point A.

[0028] Figure 3 It is another structural schematic diagram of the present invention.

[0029] Figure 4 yes Figure 3 A partial enlarged view of point B.

[0030] Figure 5 It is a schematic diagram of the cross-sectional structure of the hemostatic sealing plug of the present invention.

[0031] Figure 6 It is a structural schematic diagram of the protective cap in the present invention.

[0032] Figure 1 、 Figure 2 This is a schematic structural diagram of Example 1; Figure 3 、 Figure 4 This is a structural diagram of Example 2. DETAILED DESCRIPTION

[0033] The present invention will be further described below with reference to the accompanying drawings:

[0034] Example 1

[0035] like Figure 1 、 Figure 2The needle tip protection indwelling needle shown includes a three-way connector 13, a connecting catheter 11, a cannula seat 5, a needle handle 8, a hemostatic sealing plug 10, a puncture needle tube 2, a needle straightening device 4, a cannula 3 and a sheath 1. The front end of the cannula seat 5 is provided with a cannula connecting hole, and the cannula seat 5 on the rear side of the cannula connecting hole is provided with a mounting cavity 6 with an open rear end. The mounting cavity 6 is connected to the cannula connecting hole through a trumpet-shaped needle straightening hole; the rear part of the cannula 3 is inserted into the cannula connecting hole, the needle straightening device 4 is funnel-shaped and has an interference fit with the needle straightening hole, and the front part of the needle straightening device 4 is inserted into the rear end of the cannula 3, and the rear end of the cannula 3 is squeezed and fixed in the cannula connecting hole. The puncture needle tube 2 is passed through the cannula 3, and the front of the cannula 3 is connected to the cannula 3. The end is pointed and fits tightly against the puncture needle tube 2, and the hemostatic sealing plug 10 is arranged in the mounting cavity 6 on the rear side of the needle straightener 4 to seal the puncture needle tube 2 and the inner side of the mounting cavity 6. The needle handle 8 is covered on the open opening at the rear end of the mounting cavity 6, and the rear end of the puncture needle tube 2 is fixedly connected to the needle handle 8; an injection connector 7 is provided on one side of the sleeve seat 5 between the hemostatic sealing plug 10 and the needle straightener 4, and the connecting catheter 11 is connected to the inside of the mounting cavity 6 through the injection connector 7. The other end of the connecting catheter 11 is connected to a three-way connector 13, and a heparin cap and a protective cap are installed on the three-way connector 13 for the syringe; a hemostatic clamp 12 is provided on the connecting catheter 11; the above structure is the same as the prior art and will not be repeated. The present invention is characterized in that a protective cap 9 is provided in the mounting cavity 6 between the hemostatic sealing plug 10 and the needle handle 8, and the protective cap 9 can be freely slid along the axial direction of the puncture needle tube and is sleeved on the puncture needle tube 2, from Figure 2 、 Figure 6 As can be seen from the figure, the protective cap 9 is in the shape of a bottle cap with an open rear side, and a needle tube slide hole 20 is provided in the middle of the front side wall of the protective cap for matching with the puncture needle tube 2. The puncture needle tube 2 can slide freely forward and backward through the needle tube slide hole 20; the interior 17 of the bottle cap-shaped protective cap 9 is a protective cavity. Figure 6 It can be seen that the cross-section of the protective cavity 17 is a trapezoid that is smaller in the front and larger in the back. The inner diameter of the protective cap (the diameter of the protective cavity 17) is 3-4 times the diameter of the needle tube slide hole 20, which is more conducive to passing the needle tube tip into the protective cavity. After the protective cap is tilted, it will pass through the needle tube tip to cover and protect it. In this embodiment, the puncture needle tube 2 and the needle tube slide hole 20 are clearance-matched, and the protective cap and the mounting cavity of the cannula seat are clearance-matched. The gap between the puncture needle tube and the needle tube slide hole is larger than the gap between the protective cap and the cannula seat. A traction line 15 is provided between one side of the rear end of the protective cap 9 and the front side of the needle handle 8 in the mounting cavity. The length of the traction line between the rear end of the protective cap 9 and the front side of the needle handle 8 in the mounting cavity is less than the length of the puncture needle tube in front of the needle handle in the mounting cavity. The sum of the length of the traction line and the thickness of the protective cap (the dimension of the protective cap in the axial direction of the puncture needle tube) is not less than the length of the puncture needle tube in front of the needle handle in the mounting cavity. Figure 2 As can be seen in the figure, the traction line 15 is bent and arranged in the protective cavity. The sheath 1 is fixed on the front of the cannula seat and protects the outside of the puncture needle tube and the cannula. The sheath 1 protects the puncture needle tube tip before use.

[0036] This embodiment is further improved. The puncture needle tube 2 and the needle tube sliding hole 20 are in clearance fit. The protective cap and the mounting cavity of the sleeve seat are in interference fit. The protective cap contacts the inner wall of the mounting cavity. When the protective cap slides axially in the mounting cavity, the friction force between the protective cap and the inner wall of the mounting cavity is 1N-3N. The static friction force between the two is no more than 5 Newtons. Figure 2 、 Figure 6 As can be seen in the figure, the cross-section of the bottle cap-shaped protective cap 9 is a trapezoid with a small front and a large back, which facilitates the control of the friction between the protective cap and the sleeve seat; this structure can effectively prevent the protective cap from being prematurely removed from the rear end of the installation cavity during the process of withdrawing the puncture needle tube 2, and prevent the protection failure caused by slight adhesion or knotting of the traction line. An auxiliary line is provided between the rear end of the protective cap and the needle handle on the side opposite to the traction line. The auxiliary line and the traction line 15 are symmetrically arranged on the left and right sides of the puncture needle tube 2, and the length of the auxiliary line is 1-2 mm longer than the length of the traction line; after the traction line pulls the protective cap to tilt so that the puncture needle tube tip and the needle tube slide hole are not opposite, the auxiliary traction line and the traction line jointly pull the protective cap to slide backward in the installation cavity, avoiding the traction line unilaterally pulling the protective cap so that the protective cap is excessively deformed, the friction between the protective cap and the inner wall of the installation cavity is unstable, the relative position between the puncture needle tube tip and the protective cap changes greatly, and even the dangerous situation where the puncture needle tube tip pierces the protective cap.

[0037] The present invention further improves upon this, wherein the hemostatic sealing plug 10 is cylindrical and fits within the inner wall of the mounting cavity. A needle insertion notch 19 is provided on one side of the hemostatic sealing plug 10, extending axially (front-to-back) and radially extending therethrough. The puncture needle 2 is inserted through the needle insertion notch 19 from one side of the hemostatic sealing plug 10 and into the center of the hemostatic sealing plug. The needle insertion notch 19 is a slit cut radially into the side of the hemostatic sealing plug 10. The radial dimension of the needle insertion notch is the radius of the hemostatic sealing plug plus the radius of the puncture needle. The puncture needle can be squeezed through the needle insertion notch into the center of the hemostatic sealing plug, coaxially with the hemostatic sealing plug. The connection process between the puncture needle and the hemostatic sealing plug does not damage the tissue inside the hemostatic sealing plug, resulting in a good sealing effect. When the needle is withdrawn, there will be no bleeding or liquid leakage. Actual testing experiments have shown that an axial length of 1 mm can achieve the purpose of sealing and hemostasis. However, in actual production, for ease of installation and to prevent accidents, the axial length of the hemostatic sealing plug is usually selected to be 2-5 mm, preferably 3-4 mm. The axial length of the hemostatic sealing plug of the existing Y-type indwelling needle is usually 6-8 mm. This structure can save space in the installation cavity and provide space for the installation of the protective cap.

[0038] Example 2

[0039] like Figure 3 、 Figure 4The needle tip protection indwelling needle shown includes a three-way connector 13, a connecting catheter 11, a cannula seat 5, a needle handle 8, a hemostatic sealing plug 10, a puncture needle tube 2, a needle straightening device 4, a cannula 3 and a sheath 1. The front end of the cannula seat 5 is provided with a cannula connecting hole, and the cannula seat 5 on the rear side of the cannula connecting hole is provided with a mounting cavity 6 with an open rear end. The mounting cavity 6 is connected to the cannula connecting hole through a trumpet-shaped needle straightening hole; the rear part of the cannula 3 is inserted into the cannula connecting hole, the needle straightening device 4 is funnel-shaped and has an interference fit with the needle straightening hole, and the front part of the needle straightening device 4 is inserted into the rear end of the cannula 3, and the rear end of the cannula 3 is squeezed and fixed in the cannula connecting hole. The puncture needle tube 2 is passed through the cannula 3, and the front of the cannula 3 is connected to the cannula 3. The end is pointed and fits tightly against the puncture needle tube 2, and the hemostatic sealing plug 10 is arranged in the mounting cavity 6 on the rear side of the needle straightener 4 to seal the puncture needle tube 2 and the inner side of the mounting cavity 6. The needle handle 8 is covered on the open opening at the rear end of the mounting cavity 6, and the rear end of the puncture needle tube 2 is fixedly connected to the needle handle 8; an injection connector 7 is provided on one side of the sleeve seat 5 between the hemostatic sealing plug 10 and the needle straightener 4, and the connecting catheter 11 is connected to the inside of the mounting cavity 6 through the injection connector 7. The other end of the connecting catheter 11 is connected to a three-way connector 13, and a heparin cap and a protective cap are installed on the three-way connector 13 for the syringe; a hemostatic clamp 12 is provided on the connecting catheter 11; the above structure is the same as the prior art and will not be repeated. The present invention is characterized in that a protective cap 9 is provided in the mounting cavity 6 between the hemostatic sealing plug 10 and the needle handle 8, and the protective cap 9 can be freely slid along the axial direction of the puncture needle tube and is sleeved on the puncture needle tube 2, from Figure 2 、 Figure 6 As can be seen from the figure, the protective cap 9 is in the shape of a bottle cap with an open rear side, and a needle tube slide hole 20 is provided in the middle of the front side wall of the protective cap for matching with the puncture needle tube 2. The puncture needle tube 2 can slide freely forward and backward through the needle tube slide hole 20; the interior 17 of the bottle cap-shaped protective cap 9 is a protective cavity. Figure 6 As can be seen in the figure, the cross-section of the protective cavity 17 is a trapezoid with a smaller front and a larger back. The inner diameter of the protective cap (the diameter of the protective cavity 17) is 3-4 times the diameter of the needle tube slide hole 20, which is more convenient for passing the needle tip into the protective cavity. After the protective cap is tilted, it will pass through the needle tip to cover and protect it. In this embodiment, the puncture needle tube 2 and the needle tube slide hole 20 are clearance-matched, and the protective cap and the mounting cavity of the cannula seat are clearance-matched. A force-disconnecting connector is provided between the front end of the protective cap 9 and the rear end of the hemostatic sealing plug 10. When the force-disconnecting connector is subjected to (axial) tension exceeding the connection force, the protective cap and the hemostatic sealing plug are separated; the connection force is 0.1-10N, preferably 1-3N. Figure 4It can be seen that the force-bearing disengagement connector described in the present invention is provided with a plug-in connecting column 16 on one side of the front end of the protective cap 9, and a plug-in hole that cooperates with the plug-in connecting column 16 is provided on the rear end of the hemostatic sealing plug, and the plug-in connecting column 16 is inserted into the plug-in hole with an interference fit. The force generated by the interference fit between the plug-in connecting column 16 and the inserted plug hole can overcome the axial pulling and separate the two, which is the connecting force; when the axial tensile separation force between the protective cap and the hemostatic sealing plug is greater than the force generated by the interference fit between the plug-in connecting column and the inserted plug hole, the two are separated, and the protective cap is separated from the hemostatic sealing plug; this structure can effectively prevent the protective cap from falling out of the rear end of the installation cavity in advance during the extraction of the puncture needle tube 2. Before the protective cap is separated from the hemostatic sealing plug, the traction line 15 has been straightened and tightened, and the tip of the puncture needle tube has entered the protective cavity 17. After the protective cap is pulled and tilted, the protective cap is separated from the hemostatic sealing plug, and the tip of the puncture needle tube is inserted into the side wall of the protective cap under the action of elastic force and tension, which can effectively prevent the protection failure caused by slight adhesion or knotting of the traction line, and the protection effect is better. A pulling line 15 is provided between one side of the rear end of the protective cap 9 and the front side of the needle handle 8 where the needle is installed in the cavity. The length of the pulling line between the rear end of the protective cap 9 and the front side of the needle handle 8 where the needle is installed in the cavity is less than the length of the puncture needle tube where the needle handle is installed in the cavity. The sum of the length of the pulling line and the thickness of the protective cap (the dimension of the protective cap in the axial direction of the puncture needle tube) is not less than the length of the puncture needle tube where the needle handle is installed in the cavity. Figure 4 As can be seen in the figure, the traction wire 15 is bent and disposed within the protective cavity. The aforementioned force-disengaging connector can also be a glue point provided between one side of the front end of the protective cap and the rear end of the hemostatic sealing plug, partially bonding the front end of the protective cap to the rear end of the hemostatic sealing plug, that is, bonding the two by glue point, with the bonding force being the connecting force; when the tensile separation force between the front end of the protective cap and the rear end of the hemostatic sealing plug exceeds the bonding force, the bonding fails and the protective cap and the hemostatic sealing plug separate.

[0040] The present invention provides a pull line between the rear end of the protective cap and the front of the needle handle within the mounting cavity. The force-disengageable connector is disposed between the protective cap and the hemostatic seal on the side opposite the pull line. That is, the pull line and the force-disengageable connector are disposed on opposite sides of the puncture needle. As the needle handle pulls the protective cap backward via the pull line, before the protective cap and the hemostatic seal are separated, the pull line can tilt the protective cap, causing the tip of the puncture needle to misalign with the needle's slide hole (the tip of the puncture needle to face the inner wall of the protective cap). When the pull line disengages the protective cap from the hemostatic seal, the tip of the puncture needle is inserted into the side wall of the protective cap, resulting in enhanced protection.

[0041] The protective cap is made of rubber material and has a certain elasticity, so the tip of the puncture needle can partially penetrate into the protective cap.

[0042] The tip of the puncture needle tube is located on the opposite side of the pulling line, and the tip of the puncture needle tube and the pulling line are respectively on both sides of the axis of the puncture needle tube.

[0043] The force-disengaging connector is arranged between the protective cap and the hemostatic sealing plug on the side opposite to the traction line, that is, the traction line and the force-disengaging connector are arranged on both sides of the puncture needle tube. When the needle handle pulls the protective cap backward through the traction line, before the protective cap and the hemostatic sealing plug are separated, the traction line can pull the protective cap to tilt so that the tip of the puncture needle tube is not opposite to the needle tube sliding hole (the tip of the puncture needle tube is opposite to the inner wall of the protective cap). When the traction line pulls the protective cap and the hemostatic sealing plug to separate, the tip of the puncture needle tube is partially inserted into the side wall of the protective cap. The protection effect is better. The traction line is a flexible and bendable line such as hemp thread, cotton thread or medical suture thread. The elastic deformation of the flexible line when stretched by external force is less than 5%, and the elastic deformation of the flexible line when stretched by external force is preferably 0.5-2%. The flexible line can elastically retract backward after being elastically deformed by force, and can pull the front side wall of the protective cap in front of the tip of the puncture needle tube back so that the tip of the puncture needle tube penetrates into the front side wall of the protective cap, thereby improving stability and improving the protection effect.

[0044] The present invention is further improved. The needle handle 8 is provided with a needle tube assembly hole on the front side of the mounting cavity portion, and a dispensing hole 18 in the shape of an inverted cone is provided in front of the needle tube assembly hole. A radial glue storage hole 14 is provided on the needle handle on the side of the needle tube assembly hole behind the dispensing hole 18, which is perpendicular to the needle tube assembly hole and connected to the dispensing hole. A connecting flow channel is provided on the mounting cavity between the radial glue storage hole 14 and the dispensing hole 18, and the radial glue storage hole 14 radially penetrates the side wall of the mounting cavity. It is more effective if 2-3 radial glue storage holes 14 are evenly distributed around the circumference of the needle tube assembly hole. The existing needle handle is provided with a needle tube assembly hole on the front side of the mounting cavity portion, and a dispensing hole in the shape of an inverted cone is provided in front of the needle tube assembly hole. During assembly, glue is first dispensed in the dispensing hole. After the puncture needle is inserted into the needle tube assembly hole through the dispensing hole, the glue is mainly accumulated at the dispensing hole. There are technical requirements for the connection strength between the puncture needle tube and the needle handle. The separation force between the two must not be less than 30N to ensure that after the puncture is completed, the needle tube will not fall off into the human body when it is pulled out; in order to ensure this separation force, the inverted cone of the cylindrical part of the needle handle must be large enough and deep enough, that is, the axial depth must be long. Judging from the results of the current product pull-out separation test, all the puncture needle tubes are connected to the glue and are completely separated from the glue-dispensing hole of the inverted cone. The setting of the radial glue storage hole of the present invention makes it difficult for the dried glue to separate from the glue-dispensing hole, thereby improving the connection strength between the puncture needle tube and the needle handle. The product pull-out separation test shows that due to the setting of the glue-dispensing hole, the separation force between the puncture needle tube and the needle handle is above 50N, and most of the time, the dried glue is separated from the puncture needle tube. This structure cooperates with the tension requirement of the protective cap to prevent the accidental separation of the needle handle and the puncture needle tube due to the increase in tension during the extraction of the puncture needle tube after adding the protective cap structure.

[0045] The preparation method of the needle tip protection type indwelling needle of the present invention is as follows: during the assembly process, the front part of the needle straightening device is inserted into the rear end part of the sleeve, the front end of the sleeve is forwarded from the opening at the rear end of the installation cavity through the installation cavity and placed into the sleeve connecting hole, the needle straightening device is pressed forward, and the front end of the needle straightening device is pressed into the sleeve connecting hole; the puncture needle tube is placed into the center of the hemostatic sealing plug through the needle tube insertion groove from one side of the hemostatic sealing plug; the protective cap is sleeved on the puncture needle tube through the rear end of the puncture needle tube, and the protective cap and the hemostatic sealing plug are connected to the connection piece after being disengaged from the force; the two ends of the traction line are respectively fixedly connected to the rear end of the protective cap and the needle handle; the rear part of the puncture needle tube is inserted into the needle tube assembly hole of the needle handle, and is fixedly connected to the needle handle by dispensing glue; the front end of the puncture needle tube is forwarded from the opening at the rear end of the installation cavity through the installation cavity, the needle straightening device is placed in the sleeve, the hemostatic sealing plug and the protective cap are squeezed into the sleeve seat together, and the needle handle cover is arranged on the opening at the rear end of the installation cavity.

[0046] Another method for preparing the needle tip protection type indwelling needle of the present invention is as follows: during the assembly process, the front part of the needle straightening device is inserted into the rear end part of the sleeve, the front end of the sleeve is passed forward from the opening at the rear end of the installation cavity through the installation cavity and placed into the sleeve connecting hole, the needle straightening device is pressed forward, and the front end of the needle straightening device is pressed into the sleeve connecting hole; the puncture needle tube is placed into the center of the hemostatic sealing plug through the needle tube insertion groove from one side of the hemostatic sealing plug; the protective cap is sleeved on the puncture needle tube through the rear end of the puncture needle tube; the two ends of the traction line are respectively fixedly connected to the rear end of the protective cap and the needle handle; the rear part of the puncture needle tube is inserted into the needle tube assembly hole of the needle handle, and is fixedly connected to the needle handle by dispensing glue; the front end of the puncture needle tube is passed forward from the opening at the rear end of the installation cavity through the installation cavity and the needle straightening device and placed into the sleeve; the hemostatic sealing plug is squeezed and installed into the sleeve seat, the protective cap is installed in the sleeve seat, and the needle handle cover is set on the opening at the rear end of the installation cavity.

[0047] When the present invention is used, all operating techniques are the same as those of the existing Y-type indwelling needle. After the puncture is completed, when the puncture needle tube is pulled out, the traction line is continuously expanded as the needle handle and the puncture needle tube are pulled out. When the needle tip of the puncture needle tube enters the protective cap, the traction line is straightened. When the puncture needle tube is continued to be pulled, the traction line pulls the protective cap backward; when the protective cap is completely separated from the sleeve seat, the traction line pulls the protective cap unilaterally, which will cause the protective cap to shift. After the shift, the hole on the protective cap that matches the puncture needle tube is no longer opposite to the needle tip, and the needle tip cannot be exposed, thereby achieving a protective effect. The present invention has the advantages of simple structure, low cost, the same appearance as the commonly used Y-type indwelling needle, unchanged operating technique during use, and simple operation.

Claims

1. A needle tip protection indwelling needle, comprising a three-way connector, a connecting catheter, a cannula seat, a needle handle, a hemostatic sealing plug, a puncture needle tube, a needle straightening device, a cannula and a sheath. The front end of the cannula seat is provided with a cannula connecting hole, and the cannula seat behind the cannula connecting hole is provided with a mounting cavity with a rear end open. The mounting cavity and the cannula connecting hole are connected via a trumpet-shaped needle straightening hole transition; the rear end of the cannula is inserted into the cannula connecting hole, the needle straightening device is funnel-shaped and has an interference fit with the needle straightening hole, the front end of the needle straightening device is inserted into the rear end of the cannula, and the rear end of the cannula is squeezed and fixed The puncture needle tube is inserted into the sleeve connecting hole, the front end of the sleeve is pointed and in close contact with the puncture needle tube, the hemostatic sealing plug is arranged in the installation cavity at the rear side of the needle straightening device to seal the puncture needle tube and the inner side of the installation cavity, the needle handle cover is arranged at the rear end of the installation cavity, and the rear end of the puncture needle tube is fixedly connected to the needle handle; an injection connector is provided on the sleeve seat between the hemostatic sealing plug and the needle straightening device, the connecting catheter is connected to the installation cavity through the injection connector, and a three-way connector is installed at the other end of the connecting catheter, and a heparin cap and a protective cap are installed on the three-way connector; it is characterized in that A protective cap is provided in the mounting cavity between the hemostatic sealing plug and the needle handle, and the protective cap can be slidably mounted on the puncture needle tube along the axial direction of the puncture needle tube. A traction line is provided between the rear end of the protective cap and the needle handle, and the length of the traction line is less than the length of the puncture needle tube on the front side of the needle handle, and the sum of the length of the traction line and the thickness of the protective cap is not less than the length of the puncture needle tube on the front side of the needle handle; the protective cap contacts the inner wall of the mounting cavity, and the friction force between the protective cap and the inner wall of the mounting cavity is 0.1-10N; a force-disengagement connector is provided between the front end of the protective cap and the rear end of the hemostatic sealing plug, and when the force-disengagement connector is subjected to a tensile force exceeding the connection force, the protective cap is separated from the hemostatic sealing plug; the connection force is 0.1-10N; the force-disengagement connector is provided with a plug-in connecting column on one side of the front end of the protective cap, and a plug-in hole matching the plug-in connecting column is provided on the rear end of the hemostatic sealing plug, and the plug-in connecting column is inserted into the plug-in hole with an interference fit.

2. The needle tip shielded indwelling needle according to claim 1, characterized in that The hemostatic sealing plug is cylindrical, and one side of the hemostatic sealing plug is provided with an axially penetrating and radially arranged needle tube insertion slot. The puncture needle tube is inserted into the center of the hemostatic sealing plug through the needle tube insertion slot on one side of the hemostatic sealing plug.

3. The needle tip shielded indwelling needle according to claim 1 or 2, characterized in that The protective cap is in the shape of a bottle cap with an open rear side, and a needle tube sliding hole cooperating with the puncture needle tube is provided in the middle of the front side wall of the protective cap, and the puncture needle tube can freely slide forward and backward through the needle tube sliding hole.

4. The needle tip shielded indwelling needle according to claim 1, characterized in that A pulling line is provided between one side of the rear end of the protective cap and the same side of the needle handle, and the force-bearing disengagement connector is provided between the protective cap and the hemostatic sealing plug on the side opposite to the pulling line.

5. The needle tip shielded indwelling needle according to claim 1, characterized in that A traction line is provided between the rear end of the protective cap and the needle handle on the same side, and an auxiliary line is provided between the rear end of the protective cap and the needle handle on the opposite side of the traction line. The length of the auxiliary line is 0.3-3 mm longer than the length of the traction line.

6. The needle tip shielded indwelling needle according to claim 1, characterized in that A needle tube assembly hole is provided on the front side of the needle handle, a dispensing hole in the form of an inverted cone is provided in front of the needle tube assembly hole, and a radial glue storage hole is provided on the needle handle on one side of the needle tube assembly hole.

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