A method of using a rotating-butt intravenous indwelling needle

Abstract

This invention discloses a method for using a rotary-propelled indwelling intravenous catheter. The indwelling intravenous catheter includes a cannula, a steel needle, and a rotary propulsion mechanism. The cannula and the steel needle are coaxially sleeved together to form a catheter-needle structure, and the axial length of the cannula is less than the axial length of the steel needle. Both axes are defined as a first direction. The steel needle includes a coaxially arranged and integrally connected needle body and an observation part. The needle body has a needle tip and a needle tail end, and the observation part is located at the needle tail end. The rotary propulsion mechanism includes a guide part and a mating part that abut against each other. One of the guide part and the mating part is located on the steel needle, and the other is located on the cannula. This invention, through the spiral movement design of the guide ramp and the mating part, transforms the traditional linear propulsion mode into a controlled rotary propulsion, structurally ensuring the accuracy of the axial movement of the cannula relative to the steel needle.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a method of using a rotary-propelled indwelling intravenous catheter. Background Technology

[0002] Indwelling intravenous catheters are medical devices widely used in clinical practice for intravenous infusion, drug administration, and blood transfusion. Their core structure consists of an internal steel needle and an external cannula. Before the advent of indwelling intravenous catheters, intravenous infusion mainly relied on reusable steel needles. After the steel needle was inserted and fixed to the patient's hand, arm, or other areas, the punctured limb was basically immobile. Even slight movements of the limb could easily cause the steel needle to puncture the blood vessel, requiring the needle to be removed and re-punctured. Moreover, traditional steel needles could only be used for a maximum of one day. This not only required frequent repeated punctures, wasting puncture time, but also required repeated disinfection and reuse of the steel needle, which greatly increased the patient's puncture pain and occupied a lot of nursing staff's working time. The drawbacks of clinical use were prominent.

[0003] To address the shortcomings of traditional reusable steel needles in clinical use, indwelling intravenous catheters were developed. The cannulas of current indwelling catheters are made of Teflon, which has excellent biocompatibility and extremely low rejection rates in the human body. They can remain in the patient's blood vessels for several days. The cannulas are also flexible and bendable, allowing patients to move freely at the puncture sites such as the back of their hand, elbow, and foot. This eliminates the need for repeated daily punctures, reducing patient discomfort, saving medical staff time and effort, and reducing the consumption of puncture instruments and consumables, thus lowering medical expenses. They have now completely replaced traditional reusable steel needles and become the mainstream infusion device in clinical practice.

[0004] The existing conventional intravenous indwelling needle structure consists of a cannula fitted over a steel needle, with only a few millimeters of needle tip remaining at the tip. The standard clinical procedure uses a two-step linear push method, which is as follows: First, the needle tip penetrates the skin and the wall of the vein. After blood return is observed in the observation area, the needle is pushed forward in a straight line, pushing the entire indwelling needle forward slightly so that the tip of the cannula enters the blood vessel. Then, the cannula is pushed forward to complete the insertion of the cannula into the blood vessel.

[0005] Meanwhile, because there is a circumferential annular protrusion at the connection point between the steel needle and the cannula, this protrusion will generate resistance during the process of pushing the steel needle and cannula simultaneously after the steel needle pierces the blood vessel wall. Therefore, additional forward thrust is required to complete the cannula insertion operation.

[0006] However, this method of applying additional forward thrust has limitations in practical applications:

[0007] First, the additional forward thrust makes it difficult to achieve precise force and stroke control during the push process. If the force and stroke are too large, the needle tip is likely to penetrate the posterior wall of the vein, causing problems such as over-puncture and double puncture, which directly leads to puncture failure and damage to the blood vessel.

[0008] Secondly, since the pushing method is linear, the direction of the additional forward thrust is difficult to control during the pushing process, which can easily cause the steel needle to shake or the puncture angle to deviate, thereby reducing the stability of the indwelling needle operation and affecting the accuracy of puncture insertion.

[0009] Finally, in the existing indwelling needle insertion procedure, applying additional forward force to insert the cannula into the blood vessel is a crucial step that requires a high level of skill from novice medical staff. They often struggle to accurately control the puncture trajectory and pushing force, necessitating extensive professional training to master this technique. If insertion fails, a completely new indwelling needle must be used, which not only increases patient discomfort and delays treatment but also wastes medical time and supplies, increasing clinical costs.

[0010] Therefore, existing traditional indwelling needles require two linear pushes, and the second push requires additional forward thrust, which results in high risk of over-puncture, high operational difficulty, high failure rate, and significant patient discomfort. Overcoming these technical problems has become the urgent research topic for this invention. Summary of the Invention

[0011] The purpose of this invention is to provide a method for using a rotary-propelled indwelling intravenous catheter.

[0012] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0013] A method for using a rotary-propelled indwelling intravenous catheter, the indwelling intravenous catheter comprising a cannula, a steel needle, and a rotary-propelling mechanism;

[0014] The sleeve and the steel needle are coaxially sleeved together to form a tube-needle structure, and the axial length of the sleeve is less than the axial length of the steel needle; the axial direction of both is defined as a first direction.

[0015] The steel needle includes a needle body and an observation part that are coaxially arranged and integrally connected. The needle body has a needle tip and a needle tail, and the observation part is disposed at the needle tail.

[0016] The rotary propulsion mechanism includes a guide part and a mating part that abut against each other, wherein one of the guide part and the mating part is disposed on the steel needle and serves as a stationary part, and the other is disposed on the sleeve and serves as a rotating part;

[0017] The indwelling intravenous catheter is defined as being in its initial state before use and in its terminated state after use.

[0018] In the initial state, the tip of the steel needle extends out of the sleeve;

[0019] The guide portion has a spirally arranged guide slope, and the guide slope has an initial end corresponding to the initial state and an end corresponding to the termination state;

[0020] The usage method includes:

[0021] S1. Apply a rotational force to the rotating component to drive it to rotate around the axis of the steel needle, while keeping the stationary component stationary.

[0022] S2. During the rotation of the rotating component, the mating part moves on the guide inclined surface so that the relative contact position between the mating part and the guide part moves continuously from the initial end to the termination end, thereby driving the rotating component to make a spiral motion relative to the stationary component, so as to drive the sleeve to rotate around the axis relative to the steel needle and move linearly along the first direction.

[0023] S3. When the mating part reaches the termination end, the spiral motion of the rotating member relative to the stationary member stops and enters the termination state, and the sleeve extends out of the tip of the steel needle, thereby storing the tip of the needle inside the sleeve.

[0024] In the above scheme, the spiral movement design of the guide ramp and the mating part transforms the traditional linear propulsion mode into a controlled rotary propulsion mode, which structurally ensures the accuracy of the axial movement of the sleeve relative to the steel needle.

[0025] Compared to existing technologies where linear forced pushing leads to instability, the core advantage of this solution lies in the reversal of the propulsion force. In traditional methods, the forward thrust is easily deflected from the vessel axis, causing the needle to wobble or puncture the vessel wall. However, with this device, the operator applies a torsional force during cannulation, resulting in a uniform force on the needle and its stationary position. This rotary guidance method not only avoids the impact of sudden forward force but also improves the smoothness of the puncture process.

[0026] In a further technical solution, the guide part is disposed on the observation part and serves as a stationary component, and the mating part is disposed on the sleeve and serves as a rotating component.

[0027] The further technical solution, S2, is as follows:

[0028] S21. Rotate the sleeve to drive the mating part provided on the sleeve to rotate synchronously around the axis of the steel needle;

[0029] S22. During the rotation of the mating part around the axis of the steel needle, the mating part moves from the initial end to the terminal end along the guide slope, so that a relative spiral sliding motion is generated between the mating part and the guide part.

[0030] S23. By means of the relative spiral sliding motion between the mating part and the guiding part, the sleeve is guided to make a spiral advancing motion relative to the steel needle in the first direction.

[0031] In a further technical solution, the rotary propulsion mechanism includes a guide section and a mating section;

[0032] The guide portion includes a ridge, which is arranged along the axis of the steel needle on the outside of the observation portion and protrudes radially on the observation portion perpendicular to the first direction. The ridge is spirally arranged on the outer periphery of the observation portion. The guide slope is disposed on the ridge and near the needle tip. The termination end is disposed at the end of the guide slope near the needle tip, and the initial end is disposed at the end of the guide slope away from the needle tip.

[0033] In a further technical solution, the mating part includes an extension portion that is fixedly disposed at the end of the sleeve and protrudes radially, wherein the length extension direction of the extension portion is parallel to the axial direction of the sleeve.

[0034] In the cannula structure, the extension is provided with a guide slope corresponding to the ridge, one end of the extension near the ridge extends beyond the end of the sleeve near the ridge, and the end of the extension abuts against the guide slope.

[0035] With the above design, the sleeve can rotate stably and move forward synchronously along the guide slope under the synergistic action of the ridge and the extension, thus accurately replicating the mechanical logic of "rotation equals forward movement" and ensuring that each rotation angle corresponds strictly to the axial displacement.

[0036] A further technical solution is that the cannula includes a needle body sleeve and a needle tail sleeve that are coaxially arranged and integrally connected;

[0037] In the needle-like structure;

[0038] The needle body sleeve is fitted onto the outside of the needle body, and the needle tail sleeve is fitted onto the outside of the observation section.

[0039] Along the first direction, the axial length from the termination end to the needle tip is greater than the axial length of the sleeve;

[0040] At least one rectangular drive wing is radially protruding from the outer periphery of the needle tail sleeve, and the length extension direction of the rectangular drive wing is parallel to the first direction.

[0041] The extension is integrally connected to one of the rectangular drive wings.

[0042] With the above design, the rectangular drive wing can be turned to guide the needle body sleeve and needle tail sleeve to rotate around the steel needle axis, so that the sleeve rotates.

[0043] In a further technical solution, the rotary propulsion mechanism includes a guide section and a mating section;

[0044] In the needle-like structure;

[0045] The guide portion includes a groove disposed on the outer periphery of the observation portion. The groove opening faces the sleeve. The groove opening to the bottom of the groove extends at an angle relative to a first direction, with the angle being a first included angle. The terminating end is located at the groove opening, and the initial end is located at the bottom of the groove. The side of the needle structure closer to the steel needle axis is defined as the inner side, and the side farther from the steel needle axis is defined as the outer side. The outer peripheral surface of the observation portion is coplanar with the inner wall of the outer side of the groove and transitions smoothly.

[0046] The inner surface of the groove, which is located between the end and the beginning and has a smooth transition, is a guide slope.

[0047] In a further technical solution, the mating part includes a base protrusion extending from the end face of the sleeve along a first direction. The base protrusion is disposed corresponding to a groove and is configured to be inserted into the groove to achieve abutment and mating between the guide part and the mating part.

[0048] With the above design, the sleeve can switch between the initial state and the final state along the first direction by the cooperation of the groove and the base protrusion, thereby realizing the rotational movement.

[0049] A further technical solution is that the cannula includes a needle body sleeve and a needle tail sleeve that are coaxially arranged and integrally connected;

[0050] In the needle-like structure;

[0051] The needle body sleeve is fitted onto the outside of the needle body, and the needle tail sleeve is fitted onto the outside of the observation section.

[0052] The base protrusion is located on the end face of the needle tail sleeve away from the needle body sleeve, and the outer side of the base protrusion is coplanar with the outer peripheral surface of the needle tail sleeve and smoothly transitions.

[0053] It should be noted that this base protrusion can be made by creating a protrusion on the needle end sleeve of the cannula, or it can utilize the Luer interface protrusion of the needle end sleeve of the cannula.

[0054] Regarding the design of the base protrusion, two structural options are currently provided: First, an independent design: the base protrusion can be set as an independent structure (or integrally formed) on the needle end sleeve of the sleeve; Second, an integrated design: no additional structure is required, and the base protrusion can directly reuse the protrusion (such as Luer lug) of the Luer interface at the needle end sleeve of the sleeve (other structural matching designs are sufficient, and the Luer interface is existing technology, so it will not be elaborated on here).

[0055] With the above design, the needle tail sleeve and the groove can be precisely fitted, making the rotation operation less strenuous and more responsive.

[0056] In a further technical solution, at least one rectangular drive wing is radially protruding from the outer periphery of the needle tail sleeve.

[0057] With the above design, the rectangular drive wing can assist the fingers in applying torque, thereby improving the stability and controllability of rotational operation.

[0058] It should be noted that the present invention provides two structural designs for the rectangular drive wing. In the first embodiment, the rectangular drive wing structure described above is used; in the second embodiment, as an alternative implementation of the present invention, the rectangular drive wing can be omitted, and instead, an anti-backflow valve can be provided at the end of the needle tail sleeve of the sleeve. That is, when the needle tail sleeve is equipped with an anti-backflow valve, there is no need to additionally configure the rectangular drive wing.

[0059] Due to the application of the above-mentioned solution, the technical solution of this application has the following advantages and effects compared with the prior art:

[0060] This invention, by setting a spiral guide slope, enables the guide slope and the mating part to form a spiral moving fit, transforming the traditional linear propulsion method into a controlled rotational propulsion method, structurally ensuring the accuracy of the axial movement of the sleeve relative to the steel needle.

[0061] Specifically, the spiral guide ramp provides a preset physical movement trajectory for the mating part. When the medical staff rotates the cannula, the mating part moves along the spiral guide ramp and, under the guidance and constraint of the spiral guide ramp, generates axial displacement in a first direction. Thus, a correspondence is established between the rotation angle of the cannula and its forward distance: when the mating part moves from the initial end at the bottom of the spiral guide ramp to the terminating end at the top, the cannula moves forward from behind the needle tip to a position covering the needle tip. This process is limited by the structural stroke of the spiral guide ramp, avoiding the uncertainty caused by relying solely on the operator's feel to control the pushing distance.

[0062] Compared to existing technologies that forcefully push the cannula in a straight line, the spiral guide ramp of this invention alters the force distribution during cannula advancement. In traditional straight-line advancement, the forward thrust easily deflects the vessel axis, causing the needle to wobble or even puncture the vessel wall. In this invention, the operator primarily applies a rotational force, with the mating part gradually moving forward along the spiral guide ramp, resulting in a more stable force distribution on the needle during cannula advancement and maintaining relative stillness. This rotational guidance method reduces the impact of sudden forward force and allows the operator to perceive cannula resistance through feedback during rotation, thereby improving the smoothness of the puncture and cannula placement process.

[0063] In summary, this invention uses a spiral guide bevel for path guidance and displacement control of the mating part, achieving an operation mode in which the steel needle in the intravenous indwelling catheter remains relatively stationary while the cannula rotates and advances axially. Compared with the traditional two-step linear advancement method, this invention can improve the controllability of the cannula's advance distance and the smoothness of the insertion process while maintaining the stability of the steel needle tip, reducing clinical risks such as over-puncture and double puncture, and reducing reliance on the puncture experience of medical staff. This helps to improve the puncture success rate, reduce patient discomfort, and decrease the probability of needing to replace the indwelling catheter with a new one and repeat the puncture due to insertion failure, thus saving medical resources and nursing time. Attached Figure Description

[0064] Figure 1 This is a perspective view of the needle structure in the initial state in Embodiment 1 of the present invention (the guide part is a spiral ridge).

[0065] Figure 2 This is a perspective view of the needle structure in the terminated state in Embodiment 1 of the present invention;

[0066] Figure 3 This is a schematic diagram of the longitudinal section structure of the sleeve in Embodiment 1 of the present invention;

[0067] Figure 4 This is a front view of the needle structure in Embodiment 1 of the present invention;

[0068] Figure 5 This is a front view of the needle structure in Embodiment 1 of the present invention (an observation port is provided on the observation part).

[0069] Figure 6 This is a perspective view of the needle structure in the initial state in Embodiment 2 of the present invention (the guide part is an inclined groove).

[0070] Figure 7 This is a perspective view of the needle structure in the terminated state in Embodiment 2 of the present invention;

[0071] Figure 8 This is a schematic diagram of the longitudinal section structure of the needle body sleeve in Embodiment 2 of the present invention;

[0072] Figure 9 This is a schematic diagram of the cross-sectional structure of the observation section in Embodiment 2 of the present invention;

[0073] Figure 10 This is a perspective view of the sleeve and steel needle after being inserted in Embodiment 2 of the present invention;

[0074] Figure 11 This is a schematic diagram of the base protrusion structure in Embodiment 2 of the present invention;

[0075] Figure 12This is a schematic diagram of the outer jacket structure in Embodiment 3 of the present invention (the guide part is a spiral groove);

[0076] Figure 13 This is a front view of the needle structure in Embodiment 3 of the present invention;

[0077] Figure 14 This is a schematic diagram of the structure after the spiral groove and the limiting protrusion are properly matched in Embodiment 3 of the present invention (the guide part is a spiral groove, and the spiral groove is lower on the left and higher on the right).

[0078] Figure 15 This is a schematic diagram of the structure after the spiral groove and the limiting protrusion are properly matched in Embodiment 3 of the present invention (the guide part is a spiral groove, and the spiral groove is higher on the left and lower on the right).

[0079] Figure 16 This is a perspective view of the needle structure in the initial state in Embodiment 3 of the present invention;

[0080] Figure 17 This is a perspective view of the needle structure in the terminated state in Embodiment 3 of the present invention.

[0081] In the attached diagrams above: 1. Cannula; 11. Needle body sheath; 12. Needle tail sheath;

[0082] 121. Rectangular drive wing;

[0083] 2. Steel needle; 21. Needle body; 22. Observation section; 23. Outer cover;

[0084] 211. Needle tip; 221. Observation port;

[0085] 3. Rotary propulsion mechanism; 31. Guiding part; 32. Fitting part; 33. Guide slope;

[0086] 311. Ridge; 312. Groove; 313. Spiral groove;

[0087] 321. Extension portion; 322. Base protrusion; 323. Limiting protrusion;

[0088] 331. Termination end; 332. Initial end;

[0089] 4. Needle-like structure;

[0090] α, the first included angle;

[0091] Q, the axis of the tube needle structure. Detailed Implementation

[0092] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0093] The terms "first," "second," etc., used in this article do not specifically refer to order or sequence, nor are they intended to limit this case; they are merely used to distinguish components or operations described using the same technical terms.

[0094] The terms "connection" or "positioning" as used in this article can refer to two or more components or devices making direct physical contact with each other, or making indirect physical contact with each other, or to two or more components or devices operating or moving with each other.

[0095] The terms “include,” “including,” and “have” used in this article are all open-ended, meaning they include but are not limited to.

[0096] Unless otherwise specified, the terms used herein generally have their ordinary meaning in the context of the art, the subject matter, and the specific context. Certain terms used to describe this case will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing this case.

[0097] The terms “front,” “back,” “up,” “down,” “left,” and “right” used in this article are directional terms. In this case, they are only used to describe the positional relationship between the structures and are not intended to limit the specific direction of the protection scheme or its actual implementation.

[0098] The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the scope of this work. Singular forms such as “a,” “this,” “this,” “the,” and “the” as used herein also include plural forms.

[0099] See Figures 1-17 As shown, a method for using a rotary-propelled indwelling intravenous catheter is described. The indwelling intravenous catheter includes a cannula 1, a steel needle 2, and a rotary propulsion mechanism 3.

[0100] The sleeve 1 and the steel needle 2 are coaxially sleeved and combined to form a tube-needle structure 4, and the axial length of the sleeve 1 is less than the axial length of the steel needle 2; the axial direction of both is defined as the first direction.

[0101] The steel needle 2 includes a needle body 21 and an observation part 22 that are coaxially arranged and integrally connected. The needle body 21 has a needle tip 211 and a needle tail end, and the observation part 22 is disposed at the needle tail end.

[0102] The rotary propulsion mechanism 3 includes a guide part 31 and a mating part 32 that abut against each other. One of the guide part 31 and the mating part 32 is disposed on the steel needle 2 and serves as a stationary part, while the other is disposed on the sleeve 1 and serves as a rotating part.

[0103] The indwelling intravenous catheter is defined as being in its initial state before use and in its terminated state after use.

[0104] In the initial state, the tip 211 of the steel needle 2 extends out of the sleeve 1;

[0105] The guide portion 31 has a spirally arranged guide slope 33, and the guide slope 33 has an initial end 332 corresponding to the initial state and an end 331 corresponding to the termination state.

[0106] The usage method includes:

[0107] S1. Apply a rotational force to the rotating component, such as... Figure 1 As shown, in practice, the rectangular drive wing 121 on the sleeve 1 is directly actuated to drive the rotating part to rotate around the axis of the steel needle 2, while keeping the stationary part stationary.

[0108] S2. During the rotation of the rotating component, the mating part 32 moves on the guide inclined surface 33 so that the relative contact position between the mating part 32 and the guide part 31 moves continuously from the initial end 332 to the termination end 331, thereby driving the rotating component to make a spiral motion relative to the stationary component, so as to drive the sleeve 1 to rotate around the axis relative to the steel needle 2 and move linearly along the first direction.

[0109] S3. When the mating part 32 reaches the termination end 331, the spiral movement of the rotating part relative to the stationary part stops and enters the termination state, and the sleeve 1 extends out of the needle tip 211 of the steel needle 2, thereby storing the needle tip 211 inside the sleeve 1. Generally, in practice, the sleeve 1 will extend 2-8mm.

[0110] In this invention, the cannula 1 is made of a medical-grade flexible polymer material (such as Teflon or polyurethane); after the indwelling venous needle is placed in the human body, the cannula 1 can adapt to the direction of the blood vessel and bend accordingly, and the bending deformation of the cannula 1 does not affect the axial movement constraint of the rotary propulsion mechanism 3 along the first direction during the initial propulsion process.

[0111] In this invention, during the relative movement of the cannula 1 and the steel needle 2, after the tip 211 of the steel needle 2 pierces the blood vessel, the position of the steel needle 2 is fixed by the thumb, while the cannula 1 is rotated along the axis of the steel needle 2 by the index finger, and at the same time, it moves in a straight line along the direction of the needle tip 211.

[0112] In this invention, after the sleeve 1 and the steel needle 2 are sleeved together, their axes coincide and they are combined to form the tube needle structure 4. At this time, the axis Q of the tube needle structure is the axis of the sleeve 1 and the steel needle 2.

[0113] In this invention, the transparency of the observation section 22 is based on the ability to observe the blood return. Specifically, it can be semi-transparent, colored transparent (i.e., the blood return position inside can be observed through the color of the observation section 22 itself), or completely transparent.

[0114] Alternatively, an observation port 221 can be provided on the observation section 22, such as... Figure 5 As shown, this also allows us to observe the return of blood.

[0115] In this invention, in a plane parallel to the longitudinal section of the needle structure 4, the extension direction of the cross section of the guide slope 33 in this plane forms a first angle α with the axial direction of the steel needle 2.

[0116] The length of the guide slope 33 is matched and set according to the required axial travel of the sleeve 1 and the first included angle α. Specifically, when the axial extension distance of the sleeve 1 relative to the steel needle 2 is constant, the smaller the first included angle α, the closer the extension direction of the guide slope 33 is to the axial direction of the steel needle 2, and the greater the axial advance formed by the movement of the mating part 32 along the guide slope 33. Therefore, the length of the guide slope 33 can be reduced accordingly. The larger the first included angle α, the more the extension direction of the guide slope 33 deviates from the axial direction of the steel needle 2, and the smaller the axial advance formed by the movement of the mating part 32 along the guide slope 33. Therefore, in order to ensure that the sleeve 1 completes the predetermined axial extension distance, the length of the guide slope 33 is increased accordingly. Through the matching setting of the first included angle α and the length of the guide slope 33, the mating part 32 can move continuously and smoothly along the guide slope 33 from the initial end 332 to the terminal end 331, and finally realize the operation of the sleeve 1 extending 2-8mm relative to the steel needle 2.

[0117] The present invention transforms the traditional linear propulsion mode into a controlled rotational propulsion mode through the spiral movement design of the guide slope 33 and the mating part 32, thereby structurally ensuring the accuracy of the axial movement of the sleeve 1 relative to the steel needle 2.

[0118] At the operational level, the spiral movement design of the guide ramp 33 and the mating part 32 utilizes the physical trajectory of the guide part 31 to constrain the mating part 32. When the medical staff rotates the cannula 1, the mating part 32, guided by the guide ramp, is forced to produce an axial displacement along the first direction. This design establishes a quantitative relationship between the rotation angle and the forward distance: that is, when the mating part 32 rotates from the initial end 332 at the bottom of the guide ramp to the terminal end 331 at the top, the cannula 1 moves forward from behind the needle tip to the position covering the needle tip. This stroke, preset by the mechanical structure, eliminates the uncertainty of controlling the pushing distance by hand.

[0119] Compared to existing technologies where linear forced pushing leads to instability, the core advantage of this solution lies in the reversal of the propulsion force. In traditional methods, the forward thrust is easily deflected from the vessel axis, causing the needle 2 to wobble or puncture the vessel wall. However, in this device, the operator applies a torsional force when advancing the cannula 1, resulting in uniform force on the needle 2 and its stationary position. This rotary guidance method not only avoids the impact of sudden forward force but also allows the operator to more precisely perceive the insertion resistance through rotational feedback, greatly improving the smoothness of the puncture process.

[0120] In summary, this invention uses a spiral guide ramp 33 to guide the path and control the displacement of the mating part 32, achieving an operation mode in which the steel needle 2 in the intravenous indwelling needle remains relatively stationary while the cannula 1 rotates and advances axially. Compared with the traditional two-step linear pushing method, this invention can improve the controllability of the cannula 1's advance distance and the smoothness of the insertion process while maintaining the stability of the needle tip 211 of the steel needle 2. It reduces clinical risks such as over-puncture and double puncture, and reduces reliance on the puncture experience of medical staff. This helps to improve the puncture success rate, reduce patient pain, and reduce the probability of needing to replace the indwelling needle and re-puncture due to indwelling needle failure, thus saving medical resources and nursing time.

[0121] Preferably, the guide part 31 is disposed on the observation part 22 and serves as a stationary part, and the mating part 32 is disposed on the sleeve 1 and serves as a rotating part.

[0122] Preferably, S2 is as follows:

[0123] S21. Rotate the sleeve 1 to drive the mating part 32 provided on the sleeve 1 to rotate synchronously around the axis of the steel needle 2, as follows. Figure 1 As shown, in practice, the rectangular drive wing 121 on the sleeve 1 is directly actuated;

[0124] S22. During the rotation of the mating part 32 around the axis of the steel needle 2, the mating part 32 moves from the initial end 332 to the terminal end 331 along the guide slope 33, so that a relative spiral sliding motion is generated between the mating part 32 and the guide part 31.

[0125] S23. By means of the relative spiral sliding motion between the mating part 32 and the guiding part 31, the sleeve 1 is guided to make a spiral advancing motion relative to the steel needle 2 in the first direction.

[0126] It should be noted that the controllable rotational propulsion of the sleeve 1 is due to the fact that the movement stroke and force of the end of the mating part 32 on the guide slope 33 can be controlled. Therefore, it is feasible to achieve the rotational propulsion of the sleeve 1 through controllable stroke.

[0127] To achieve the rotational forward propulsion operation, this application provides three embodiments, as follows:

[0128] Example 1, as Figure 1 - Figure 5 As shown, the rotary propulsion mechanism 3 includes a guide part 31 and a mating part 32;

[0129] The guide portion 31 includes a ridge 311, which is arranged along the axial direction of the steel needle 2 on the outside of the observation portion 22. The ridge 311 protrudes radially on the observation portion 22 perpendicular to the first direction. The ridge 311 is spirally arranged on the outer periphery of the observation portion 22. The guide slope 33 is disposed on the ridge 311 and near the needle tip 211. The termination end 331 is disposed at the end of the guide slope 33 near the needle tip 211. The initial end 332 is disposed at the end of the guide slope 33 away from the needle tip 211.

[0130] The mating part 32 includes an extension part 321 that is fixedly disposed at the end of the sleeve 1 and protrudes radially, and the length extension direction of the extension part 321 is parallel to the axial direction of the sleeve 1.

[0131] In the needle structure 4, the extension 321 is provided corresponding to the guide slope 33 of the protrusion 311. One end of the extension 321 near the protrusion 311 extends beyond the end of the sleeve 1 near the protrusion 311, and the end of the extension 321 abuts against the guide slope 33.

[0132] With the above design, the sleeve 1 can rotate stably and move forward synchronously along the guide slope 33 under the synergistic action of the ridge 311 and the extension 321, thereby accurately replicating the mechanical logic of rotation and forward movement, and ensuring that each rotation angle and axial displacement strictly correspond.

[0133] Specifically, during operation, the end of the extension 321 abuts against the guide slope 33 and is positioned at the initial end 332. Then, the needle tip 211 of the needle body 21 is pushed subcutaneously. After blood return is observed in the observation section 22, the observation section 22 of the steel needle 2 is fixed with the thumb and middle finger (or index finger). Then, with the axis of the steel needle 2 as the center, the extension 321 is rotated counterclockwise with the index finger (or middle finger; left-handed users can choose clockwise), moving it from the initial end 332 to the termination end 331. This design transforms the original forceful forward pushing action into a rotational propulsion, making the propulsion process controllable and smooth, avoiding problems of uncoordinated movements.

[0134] Preferably, in a plane parallel to the longitudinal section of the needle structure 4, the extension direction of the section of the guide slope 33 in this plane forms a first angle α with the axial direction of the steel needle 2;

[0135] The end face of the extension 321 near the ridge 311 is in contact with the guide slope 33 and the connection between the two is smooth.

[0136] In this invention, the end face of the extension 321 near the protruding ridge 311 is also inclined. Only in this way can it be ensured that it fits the guide slope 33 and the connection is smooth.

[0137] The first included angle α is preferably an acute angle. This angle range can ensure that the axial force required for rotational propulsion is sufficient, and can also avoid stress concentration and wear caused by excessive angle when the extension 321 contacts the guide slope 33.

[0138] Preferably, the cannula 1 includes a needle body sleeve 11 and a needle tail sleeve 12 that are coaxially arranged and integrally connected;

[0139] In needle structure 4;

[0140] The needle body sleeve 11 is fitted onto the outside of the needle body 21, and the needle tail sleeve 12 is fitted onto the outside of the observation section 22.

[0141] Along the first direction, the axial length from the termination end 331 to the needle tip 211 is greater than the axial length of the sleeve 1;

[0142] At least one rectangular drive wing 121 is radially protruding from the outer periphery of the needle tail sleeve 12, and the length extension direction of the rectangular drive wing 121 is parallel to the first direction.

[0143] The extension 321 is integrally connected to one of the rectangular drive wings 121.

[0144] With the above design, when the sleeve 1 rotates, the needle tail sleeve 12 can be guided to rotate around the axis of the steel needle 2 by moving the rectangular drive wing 121.

[0145] It should be noted that, along the first direction, the axial length from the termination end 331 to the needle tip 211 is greater than the length of the sleeve 1; therefore, when the sleeve 1 is in the initial state, the needle tip 211 of the steel needle 2 extends out of the sleeve 1; while when the sleeve 1 is in the termination state, the sum of the length of the extension 321 and the length of the sleeve 1 allows the needle tip 211 of the steel needle 2 to be located inside the sleeve 1.

[0146] At least one rectangular drive wing 121 is radially protruding from the outer periphery of the needle tail sleeve 12. When there are multiple rectangular drive wings 121, all rectangular drive wings 121 are evenly distributed in a ring around the axis of the sleeve 1 on the outer periphery of the sleeve 1, and one of them is designed integrally with the extension 321.

[0147] Example 2, as Figures 6-11 As shown, the rotary propulsion mechanism 3 includes a guide part 31 and a mating part 32;

[0148] In needle structure 4;

[0149] The guide portion 31 includes a groove 312 disposed on the outer periphery of the observation portion 22. The groove opening of the groove 312 faces the sleeve 1. The groove opening to the bottom of the groove 312 extends at an angle relative to a first direction and the angle of inclination is a first included angle α. The termination end 331 is located at the groove opening of the groove 312, and the initial end 332 is located at the bottom of the groove 312. The side of the needle structure 4 closer to the axis of the steel needle 2 is defined as the inner side, and the side farther from the axis of the steel needle 2 is defined as the outer side. The outer peripheral surface of the observation portion 22 is coplanar with the inner wall of the outer side of the groove 312 and transitions smoothly.

[0150] The inner surface of the groove 312, which is located between the termination end 331 and the initial end 332 and has a smooth transition, is a guide slope 33.

[0151] The mating part 32 includes a base protrusion 322 extending from the end face of the sleeve 1 along a first direction. The base protrusion 322 is disposed corresponding to the groove 312 and is configured to be inserted into the groove 312 to achieve the abutment and mating of the guide part 31 and the mating part 32.

[0152] With the above design, the sleeve 1 can switch between the terminated state and the initial state along the first direction by the cooperation of the groove 312 and the base protrusion 322, thereby realizing the rotational movement action.

[0153] The guide slope 33 fits tightly against the surface of the base protrusion 322, ensuring a smooth and unobstructed movement. At the same time, the design of the guide slope 33 effectively controls the stroke accuracy and repeatability error of the sleeve 1 displacement, thereby ensuring the reliability and consistency of the extension and retraction of the steel needle 2.

[0154] Specifically, before operation, the sleeve 1 is in its initial state, with the top of the base protrusion 322 positioned at the initial end 332 on the guide slope 33 within the groove 312, as shown below. Figure 7 The needle tip 211 of the steel needle 2 extends out of the cannula 1. Then, the needle tip 211 of the needle body 21 is pushed subcutaneously, and blood is observed in the observation section 22 (return blood). The observation section 22 of the steel needle 2 is fixed with the thumb and middle finger (or index finger). Then, the base protrusion 322 is rotated counterclockwise (or clockwise if left-handed) around the axis of the steel needle 2 with the index finger (or middle finger), so that the base protrusion 322 moves from the initial end 332 to the termination end 331. During this process, the base protrusion 322 moves smoothly along the guide ramp 33, driving the cannula 1 forward axially until the cannula 1 is completely reset to the termination state, and the needle tip 211 of the steel needle 2 is completely retracted into the cannula 1, meaning that the cannula 1 has entered the blood vessel. Thus, the original forceful forward pushing action is transformed into a rotational forward pushing action.

[0155] The outer peripheral surface of the observation section 22 is coplanar with the outer inner wall of the groove 312 and has a smooth transition, meaning that the outer inner wall of the groove 312 is open.

[0156] Preferably, the cannula 1 includes a needle body sleeve 11 and a needle tail sleeve 12 that are coaxially arranged and integrally connected;

[0157] In needle structure 4;

[0158] The needle body sleeve 11 is fitted onto the outside of the needle body 21, and the needle tail sleeve 12 is fitted onto the outside of the observation section 22.

[0159] The base protrusion 322 is disposed on the end face of the needle tail sleeve 12 away from the needle body sleeve 11, and the outer side of the base protrusion 322 is coplanar with the outer peripheral surface of the needle tail sleeve 12 and smoothly transitions.

[0160] With the above design, the needle tail sleeve 12 and the groove 312 can be precisely fitted, making the rotation operation less strenuous and more responsive.

[0161] That is, the base protrusion 322 is located on the end face of the needle tail sleeve 12 away from the needle body sleeve 11, so that the base protrusion 322 can be accurately aligned with the groove 312, ensuring that there is no deviation during initial insertion.

[0162] It should be noted that the base protrusion 322 can be made by making a protrusion on the needle tail sleeve 12 of the sleeve 1, or by utilizing the Luer interface protrusion of the needle tail sleeve 12 of the sleeve 1.

[0163] That is, regarding the design of the base protrusion 322, the following structural solutions are currently provided: First, independent design: the base protrusion 322 can be set as an independent structure (or integrally formed) on the needle tail sleeve 12 of the sleeve 1; Second, integrated design: no additional structure is required, the base protrusion 322 can directly reuse the protrusion (such as Luer lug) of the Luer interface at the tail end of the needle tail sleeve 12 of the sleeve 1 (other structural matching designs are sufficient, the Luer interface is existing technology, and will not be elaborated on here).

[0164] Preferably, at least one rectangular drive wing 121 is radially protruding from the outer periphery of the needle tail sleeve 12.

[0165] With the above design, the rectangular drive wing 121 can assist the finger in applying torque, thereby improving the stability and controllability of the rotation operation. The rectangular drive wing 121 can be one or more, or when there are multiple, they are evenly distributed in a ring around the axis of the needle tail sleeve 12. In some specific embodiments, the outer periphery of the needle tail sleeve 12 is recessed with a friction-increasing groove to assist the finger in applying torque.

[0166] It should be noted that the present invention can provide the following structural design for the rectangular drive wing 121. In the first embodiment, the above-described rectangular drive wing 121 structure is adopted; in the second embodiment, as an alternative implementation of the present invention, the rectangular drive wing 121 can be omitted, and instead an anti-backflow valve can be provided at the end of the needle tail sleeve 12 of the sleeve 1. Therefore, when the needle tail sleeve 12 is equipped with an anti-backflow valve, it is not necessary to additionally configure the rectangular drive wing 121.

[0167] Preferably, the first included angle α is 45-60 degrees. In this case, the extension direction of the guide slope 33 will not be close to the axial direction of the steel needle 2, that is, the axial length of the guide slope 33 will not be set very long.

[0168] With the above design, when the extension 321 rotates from the initial end 332 to the terminal end 331, the extension 321 moves continuously along the guide slope 33, causing the cannula 1 to generate axial displacement relative to the steel needle 2. Given a fixed extension trajectory of the guide slope 33, the axial displacement of the cannula 1 is proportional to the rotation angle of the extension 321, allowing the operator to intuitively predict the advance distance of the cannula 1 through the rotation angle and scale markings (optional design). This reduces the uncertainty caused by relying on manual control of the insertion depth, lowers the dependence on puncture experience, and is particularly beneficial for primary healthcare personnel to quickly master the puncture and catheterization rhythm.

[0169] Preferably, when viewed from the cross-sectional angle of the needle structure 4, the central angle of the groove 312 in the radial direction of the observation part 22 is greater than or equal to 120 degrees.

[0170] With the above design, the groove 312 can have sufficient containment space to ensure that the base protrusion 322 is always within the constraint range during rotation and movement, avoiding the base protrusion 322 from falling out of the guide slope 33 due to excessive rotation angle, or preventing the base protrusion 322 from having insufficient movement during rotation and movement, and the sleeve 1 from being unable to fully reset to the termination state.

[0171] Preferably, during the transition from the initial state to the terminated state, the sleeve 1 rotates 80-100 degrees around the axis of the steel needle 2, and the rotation direction of the sleeve 1 is clockwise or counterclockwise.

[0172] With the above design, the axial movement of the cannula 1 can be controlled by controlling the angle of rotation of the cannula 1 relative to the axis of the steel needle 2, thereby accurately matching the puncture requirements of different blood vessel depths; at the same time, the rotation direction of the cannula 1, whether clockwise or counterclockwise, can ensure that the cannula 1 is suitable for operators with different operating habits.

[0173] Compared to the first embodiment, which uses a radially exposed protrusion of ridge 311 and extension 321, this second embodiment uses an embedded moving structure with groove 312 and base protrusion 322. The whole structure has no radially protruding components, the structure layout is compact and regular, the moving limit fit is higher, the guiding operation is more stable, and it is not easy to produce radial offset and moving jamming. At the same time, it is easy to integrate injection molding, the structure has good durability, and the mass production assembly is convenient. It is suitable for general clinical puncture scenarios and the batch application of miniaturized and standardized indwelling needles.

[0174] In summary, Example 1 and Example 2 can be freely selected during use. For example, in actual operation, Example 1 can be selected if stability of puncture and feeding accuracy are desired, while Example 2 can be selected if a simple and compact structure, stable operation and adaptability to general clinical and mass production needs are desired.

[0175] Example 3, as Figures 12-17 As shown, the steel needle 2 includes a needle body 21, an observation part 22, and an outer sleeve 23. The needle body 21 and the observation part 22 are coaxially arranged and integrally connected. The observation part 22 and the outer sleeve 23 are coaxially sleeved and spaced apart. The gap between the observation part 22 and the outer sleeve 23 forms an accommodating space.

[0176] The cannula 1 includes a needle body sleeve 11 and a needle tail sleeve 12 that are coaxially arranged and integrally connected;

[0177] In the needle structure 4 formed by assembling the steel needle 2 and the sleeve 1, the needle body sleeve 11 is correspondingly sleeved on the outside of the needle body 21, and the needle tail sleeve 12 is correspondingly sleeved on the outside of the observation part 22 and extends into the receiving space.

[0178] On the cross-section of the needle structure 4, the central angle corresponding to the outer sleeve 23 is greater than or equal to 120 degrees.

[0179] The rotary propulsion mechanism 3 includes a guide part 31 and a mating part 32;

[0180] The guide portion 31 includes a spiral groove 313 disposed on the inner sidewall of the outer sleeve 23. The spiral groove 313 is formed by a radial recess in the inner sidewall of the outer sleeve 23 perpendicular to the first direction, and the spiral axis of the spiral groove 313 is parallel to the first direction.

[0181] The end point of the spiral groove 313 near the needle body 21 is the termination end 331, and the end point away from the needle body 21 is the initial end 332; and the inner surface of the spiral groove 313 between the termination end 331 and the initial end 332, which forms a smooth transition, is the guide slope 33.

[0182] The mating part 32 includes a limiting protrusion 323, which is positioned and connected to the outer side wall of the needle tail sleeve 12 of the sleeve 1.

[0183] The limiting protrusion 323 is configured to be fitted into the spiral groove 313 to achieve the abutment and engagement of the guide part 31 and the mating part 32.

[0184] At least one rectangular drive wing 121 is radially protruding from the outer periphery of the needle tail sleeve 12, and the rectangular drive wing 121 is located at the end of the outer sleeve 23 near the needle body 21.

[0185] In use, the rectangular drive wing 121 is turned, and then the needle tail sleeve 12 and the needle body sleeve 11 are driven to rotate around the axis of the steel needle 2. During the rotation of the needle tail sleeve 12, the limiting protrusion 323 moves from the initial end 332 to the terminal end 331 along the spiral groove 313. Thus, through the movement cooperation between the mating part 32 and the guide part 31, the sleeve 1 is driven to spiral feed relative to the steel needle 2. When the limiting protrusion 323 reaches the terminal end 331 of the guide slope 33, the sleeve 1 completes the axial movement. At this time, the needle tip 211 of the steel needle 2 is completely inside the sleeve 1.

[0186] Compared to Embodiment 2, Embodiment 3 utilizes the accommodating space to completely conceal the movement and engagement of the limiting protrusion 323 and the spiral groove 313 within the catheter structure 4. This double-wall support design, combined with the rigid constraint of the outer sleeve 23 at a central angle greater than or equal to 120 degrees in cross-section, not only gives the indwelling needle higher radial torsional stiffness but also protects the internal engagement trajectory from external physical interference (such as direct pressure from medical personnel's fingers or external friction). This physically eliminates the possibility of the cannula 1 becoming eccentric or deformed due to external force compression, greatly improving the trajectory linearity and axial transmission accuracy during the spiral feed process. In other words, Embodiment 3, through its double-layer coaxial nested high-rigidity limiting and the force-saving structure of the external rectangular drive wing, offers superior control certainty and over-penetration safety in scenarios requiring higher stability, anti-interference, and precise operation of the indwelling catheter, such as deep vein puncture, fragile vessel puncture, or complex clinical infusion.

[0187] It is important to note that Figure 15 and Figure 16 The image shows two cases of the spiral groove 313, in which... Figure 15 In the case where the spiral groove 313 is lower on the left and higher on the right, sleeve 1 needs to be rotated counterclockwise to extend; while Figure 16 In the case where the spiral groove 313 is higher on the left and lower on the right, the sleeve 1 needs to be rotated clockwise to extend.

[0188] The working principle of this rotary-advanced indwelling intravenous catheter is illustrated by example 2:

[0189] Before the procedure, the cannula 1 is in its initial state, with the top of the base protrusion 322 positioned at the initial end 332 on the guide ramp 33 within the groove 312, and the needle tip 211 of the steel needle 2 extending out of the cannula 1. The steel needle 2 is then inserted into the patient's blood vessel. When blood appears in the observation section 22, the clinician or nurse holds the observation section 22 of the steel needle 2 with their thumb and middle finger. Then, the clinician or nurse uses their index finger to rotate the rectangular drive wing 121 counterclockwise around the axis of the steel needle 2 by 80-100 degrees. During this rotation, the base protrusion 322 moves along the guide ramp 33, causing the cannula 1 to rotate relative to the axis of the steel needle 2 and move linearly along the first direction (i.e., the puncture direction of the steel needle 2), thus switching the cannula 1 from its initial state to its terminated state. The cannula 1 is then inserted into the patient's blood vessel through the conical surface 111 at its tip, completing the placement. The entire advancement process of the sleeve 1 is limited by the inclination angle and length of the guide slope 33, ensuring that the movement path is stable and controllable; when the mating part 32 reaches the end 331 of the guide slope 33, the sleeve 1 completes the axial movement, at which time the tip 211 of the steel needle 2 is completely inside the sleeve 1.

[0190] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for using a rotary-advanced indwelling intravenous catheter, characterized in that: The indwelling intravenous catheter includes a cannula (1), a steel needle (2), and a rotary propulsion mechanism (3); The sleeve (1) and the steel needle (2) are coaxially sleeved and combined to form a tube-needle structure (4), and the axial length of the sleeve (1) is less than the axial length of the steel needle (2); the axial direction of both is defined as the first direction. The steel needle (2) includes a needle body (21) and an observation part (22) that are coaxially arranged and integrally connected. The needle body (21) has a needle tip (211) and a needle tail end, and the observation part (22) is disposed at the needle tail end. The rotary propulsion mechanism (3) includes a guide part (31) and a mating part (32) for abutting and cooperating. One of the guide part (31) and the mating part (32) is disposed on the steel needle (2) and serves as a stationary part, while the other is disposed on the sleeve (1) and serves as a rotating part. The indwelling intravenous catheter is defined as being in its initial state before use and in its terminated state after use. In the initial state, the tip (211) of the steel needle (2) extends out of the sleeve (1). The guide portion (31) has a spirally arranged guide slope (33), and the guide slope (33) has an initial end (332) corresponding to the initial state and an end (331) corresponding to the termination state. The usage method includes: S1. Apply a rotational force to the rotating component to drive it to rotate around the axis of the steel needle (2), while keeping the stationary component stationary. S2. During the rotation of the rotating part, the mating part (32) moves on the guide slope (33) so that the relative contact position between the mating part (32) and the guide part (31) moves continuously from the initial end (332) to the final end (331), thereby driving the rotating part to make a spiral motion relative to the stationary part, so as to drive the sleeve (1) to rotate around the axis relative to the steel needle (2) and move linearly along the first direction; S3. When the mating part (32) reaches the termination end (331), the spiral motion of the rotating member relative to the stationary member stops and enters the termination state, and the sleeve (1) extends out of the needle tip (211) of the steel needle (2), thereby storing the needle tip (211) inside the sleeve (1).

2. The method of using the rotary-advanced indwelling intravenous catheter according to claim 1, characterized in that: The guide part (31) is disposed on the observation part (22) and serves as a stationary part, and the fitting part (32) is disposed on the sleeve (1) and serves as a rotating part.

3. The method of using the rotary-advanced indwelling intravenous catheter according to claim 2, characterized in that: S2 specifically refers to: S21. Rotate the sleeve (1) to drive the mating part (32) provided on the sleeve (1) to rotate synchronously around the axis of the steel needle (2); S22. During the rotation of the mating part (32) around the axis of the steel needle (2), the mating part (32) moves from the initial end (332) to the final end (331) along the guide slope (33) so that a relative spiral sliding motion is generated between the mating part (32) and the guide part (31); S23. By means of the relative spiral sliding motion between the mating part (32) and the guide part (31), the sleeve (1) is guided to make a spiral advancing motion relative to the steel needle (2) in the first direction.

4. The method of using the rotary-advanced indwelling intravenous catheter according to claim 1, characterized in that: The rotary propulsion mechanism (3) includes a guide (31) and a mating part (32); The guide portion (31) includes a ridge (311) which is arranged on the outside of the observation portion (22) along the axis of the steel needle (2) and the ridge (311) protrudes radially on the observation portion (22). The ridge (311) is spirally arranged on the outer periphery of the observation portion (22). The guide slope (33) is arranged on the ridge (311) and close to the needle tip (211). The termination end (331) is arranged at the end of the guide slope (33) close to the needle tip (211). The initial end (332) is arranged at the end of the guide slope (33) away from the needle tip (211).

5. The method of using the rotary-advancing indwelling intravenous catheter according to claim 4, characterized in that: The mating part (32) includes an extension part (321) that is fixedly disposed at the end of the sleeve (1) and protrudes radially, wherein the length extension direction of the extension part (321) is parallel to the axial direction of the sleeve (1); In the needle structure (4), the extension (321) is provided with a guide slope (33) corresponding to the ridge (311). The end of the extension (321) near the ridge (311) extends beyond the end of the sleeve (1) near the ridge (311), and the end of the extension (321) abuts against the guide slope (33).

6. The method of using the rotary-advanced indwelling intravenous catheter according to claim 5, characterized in that: The cannula (1) includes a needle body sleeve (11) and a needle tail sleeve (12) that are coaxially arranged and integrally connected. In the needle structure (4); The needle body sleeve (11) is fitted onto the outside of the needle body (21), and the needle tail sleeve (12) is fitted onto the outside of the observation part (22); Along the first direction, the axial length from the termination end (331) to the needle tip (211) is greater than the axial length of the sleeve (1); At least one rectangular drive wing (121) is radially protruding from the outer periphery of the needle tail sleeve (12), and the length extension direction of the rectangular drive wing (121) is parallel to the first direction; The extension (321) is integrally connected to one of the rectangular drive wings (121).

7. The method of using the rotary-advancing indwelling intravenous catheter according to claim 1, characterized in that: The rotary propulsion mechanism (3) includes a guide (31) and a mating part (32); In the needle structure (4); The guide part (31) includes a groove (312) disposed on the outer periphery of the observation part (22). The groove (312) has its opening facing the sleeve (1). The groove (312) extends from its opening to its bottom at an angle relative to a first direction, with the angle being a first included angle (α). The termination end (331) is located at the opening of the groove (312), and the initial end (332) is located at the bottom of the groove (312). The side of the needle structure (4) closest to the axis of the steel needle (2) is defined as the inner side, and the side away from the axis of the steel needle (2) is defined as the outer side. The outer periphery of the observation part (22) is coplanar with the inner wall of the outer side of the groove (312) and transitions smoothly. The inner surface of the groove (312) that is located between the end (331) and the beginning (332) and has a smooth transition is the guide slope (33).

8. The method of using the rotary-advanced indwelling intravenous catheter according to claim 7, characterized in that: The mating part (32) includes a base protrusion (322) extending from the end face of the sleeve (1) in a first direction. The base protrusion (322) is provided corresponding to the groove (312), and the base protrusion (322) is configured to be inserted into the groove (312) to achieve the abutment fit between the guide part (31) and the mating part (32).

9. The method of using the rotary-advancing indwelling intravenous catheter according to claim 8, characterized in that: The cannula (1) includes a needle body sleeve (11) and a needle tail sleeve (12) that are coaxially arranged and integrally connected. In the needle structure (4); The needle body sleeve (11) is fitted onto the outside of the needle body (21), and the needle tail sleeve (12) is fitted onto the outside of the observation part (22); The base protrusion (322) is disposed on the end face of the needle tail sleeve (12) away from the needle body sleeve (11), and the outer side of the base protrusion (322) is coplanar with the outer peripheral surface of the needle tail sleeve (12) and smoothly transitions.

10. The method of using the rotary-advanced indwelling intravenous catheter according to claim 9, characterized in that: At least one rectangular drive wing (121) is radially protruding from the outer periphery of the needle tail sleeve (12).

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