Medical trocar

Abstract

The medical trocar comprises a puncture needle and an indwelling cannula, and is characterized in that the medical trocar is further provided with a guide cannula, the puncture needle comprises a puncture needle body, a puncture needle base, the guide cannula and the indwelling cannula which are sequentially connected, the puncture needle is matched with the guide cannula, the puncture needle body penetrates into the guide cannula, and the indwelling cannula penetrates into the puncture needle body. The indwelling cannula is sleeved on the guide cannula, and a smooth structure is arranged from the head of the medical cannula to the outer side of an indwelling cannula body. And a blood return display structure is arranged on the puncture needle. A blood overflow preventing structure is arranged on the medical trocar. The indwelling cannula is simple in structure, relatively easy to enter a preset position, convenient for doctors to puncture and position, high in puncture success rate, good in structural stability, convenient for the doctors to judge whether the puncture needle enters the blood vessel of a patient, and capable of preventing the blood of the patient from flowing out to cause pollution and / or preventing germs and foreign matters from entering the puncture needle.

Description

Technical Field

[0001] This application relates to a medical cannula needle, which is mainly suitable for medical infusion or pressure measurement. Background Technology

[0002] I. Indwelling catheters have gained widespread use due to their ability to reduce the pain of multiple punctures compared to ordinary steel needles. Current medical cannulas typically consist of an indwelling cannula and a puncture needle. The puncture needle is inserted into the blood vessel for positioning and then removed, while the indwelling cannula remains in the vessel for subsequent infusion or pressure measurement. Because the indwelling cannula and puncture needle are used in conjunction, the size of the puncture needle must match the size of the indwelling cannula, and different sizes of cannulas are selected according to clinical needs. When the patient's blood vessel for infusion or pressure measurement is thin or atherosclerotic and difficult to puncture, and a larger cannula is required clinically, the difficulty in puncturing and positioning leads to repeated procedures, causing harm to the patient and increasing the workload and psychological stress of medical staff. Furthermore, the puncture needle corresponding to a larger indwelling cannula is thicker, resulting in greater vessel damage. After clinical treatment, the cannula is removed, making hemostasis more difficult compared to a smaller cannula, easily causing subcutaneous hematoma. In addition, the indwelling cannula has a thin wall and a soft texture (making it comfortable for the patient after insertion into the blood vessel). When the puncture needle is pulled out, the indwelling cannula is easily deformed due to resistance during the process of pushing it into the blood vessel, which can lead to puncture failure.

[0003] Second, the catheter hub of an open indwelling needle is usually open at the end, so when the needle is withdrawn after the puncture, blood leakage is likely to occur, increasing the risk of medical staff being infected with bloodborne diseases. Utility Model Content

[0004] The technical problem solved by this application is to overcome the aforementioned shortcomings of the prior art and to provide a medical cannula with a simple structure, relatively easy access to blood vessels, and reduced damage to blood vessels. Based on existing indwelling needles, a guiding cannula is added between the indwelling cannula and the puncture needle. With an indwelling cannula of the same diameter, the diameter of the puncture needle used in this application is relatively smaller than that of a conventional type. The guiding cannula guides the indwelling cannula into the patient's blood vessel for a longer distance than a conventional puncture needle, thus resulting in a higher success rate for puncture. Furthermore, the addition of the guiding cannula between the indwelling cannula and the puncture needle enhances the structural stability of the indwelling cannula, making it less prone to deformation.

[0005] The technical solution adopted by this application to solve the above-mentioned technical problems is: a medical cannula needle, including a puncture needle and an indwelling cannula, characterized in that: a guide cannula is also provided. The puncture needle includes a puncture needle body and a puncture needle seat connected in sequence. The guide cannula and the indwelling cannula are both hollow through-structures. The puncture needle and the guide cannula cooperate, with the puncture needle body penetrating into the guide cannula and the indwelling cannula being fitted onto the guide cannula. The head of the medical cannula needle to the outer side of the indwelling cannula is a smooth structure. Through the above design, this application enables the puncture needle + guide cannula + indwelling cannula to be used together. When the medical cannula needle of this application with the combination structure of puncture needle + guide cannula + indwelling cannula is used for puncture, the puncture needle first punctures the blood vessel, the tip of the guide cannula is completely inserted into the blood vessel, the puncture needle is withdrawn, and the guide cannula and the indwelling cannula continue to enter the blood vessel. When the tip of the indwelling cannula is completely inserted into the blood vessel, the guide cannula can be withdrawn, and the indwelling cannula continues to enter the blood vessel, and then infusion or pressure measurement is performed. The inner and outer diameters of the puncture needle and the guiding cannula in this design are smaller than those of the blood vessel or indwelling cannula. Therefore, the puncture needle is easier to enter the blood vessel and less likely to puncture it again after entry. This design not only meets the size requirements of the indwelling cannula but also improves the success rate of puncture. At the same time, it reduces the risk of bleeding after the indwelling cannula is removed (the puncture needle of this application has a smaller diameter than ordinary cannula needles of the same size, thus causing a smaller puncture wound to the blood vessel). This reduces the physical and mental suffering of patients, reduces the workload and stress of medical staff, and expands the scope of application of medical cannula needles. The guiding cannula is added between the indwelling cannula and the puncture needle. On the one hand, it enhances the structural stability of the indwelling cannula, making it less prone to deformation. On the other hand, the guiding cannula has an expanding effect when entering the patient's skin and blood vessels, making it easier for relatively larger diameter indwelling cannulas to enter the patient's skin and blood vessels.

[0006] The medical puncture needle described in this application is equipped with a blood return display structure (such as a blood return groove or a transparent puncture needle hub) to facilitate doctors in timely determining whether the puncture needle has entered the patient's blood vessel.

[0007] The blood return display structure includes a blood return groove on the puncture needle body. The guide cannula and indwelling cannula are both made of transparent or semi-transparent materials. The outer diameter of the puncture needle body is smaller than the inner diameter of the guide cannula, allowing the patient's blood to flow through the blood return groove into the space between the puncture needle body and the guide cannula, so that the doctor can directly detect the blood flow from the outside of the guide cannula and indwelling cannula.

[0008] The medical cannula described in this application is equipped with a blood spill prevention structure to prevent the patient's blood from flowing out and causing contamination.

[0009] The blood spill prevention structure includes a breathable membrane at the tail of the puncture needle. The puncture needle includes a needle body, a needle seat, and a tail connected in sequence. A breathable membrane is provided inside the tail of the puncture needle to prevent the patient's blood from flowing out.

[0010] The blood spill prevention structure includes a guide cannula anti-backflow plug. The guide cannula includes a guide cannula head, a guide cannula body, and a guide cannula seat connected in sequence. The guide cannula seat is provided with an anti-backflow plug. When the puncture needle is pulled out of the guide cannula, the anti-backflow plug blocks the communication between the guide cannula and the outside, which not only prevents a large amount of blood from flowing out rapidly, but also allows the presence of blood in the guide cannula seat to determine whether the guide cannula has entered a blood vessel.

[0011] The blood spill prevention structure includes an anti-backflow plug for the indwelling cannula seat. The indwelling cannula includes an indwelling cannula head, an indwelling cannula body, and an indwelling cannula seat connected in sequence. An anti-backflow plug is installed inside the indwelling cannula seat. When the guide cannula is pulled out, the anti-backflow plug blocks the communication between the indwelling cannula and the outside, which not only prevents a large amount of blood from flowing out rapidly, but also allows the presence of blood at the indwelling cannula seat to determine whether the indwelling cannula has entered a blood vessel.

[0012] When the syringe or infusion device is connected to the guide cannula or indwelling cannula, the anti-backflow plug on it is opened, allowing for aspiration, infusion, or pressure measurement.

[0013] The blood spill prevention structure includes an isolation plug for the indwelling cannula seat. The indwelling cannula includes an indwelling cannula head, an indwelling cannula body, and an indwelling cannula seat connected in sequence. A soft and elastic isolation plug is provided inside the indwelling cannula seat. When the guide cannula is pulled out, the isolation plug seals the communication between the indwelling cannula and the outside, preventing blood or infused fluids from flowing out and preventing bacteria and foreign objects from entering the indwelling cannula.

[0014] The indwelling cannula seat anti-backflow plug and the guide cannula seat anti-backflow plug of this application are both composed of a round plug and a tapered tube. The round plug is made of soft elastic material and has a straight or cross-shaped slit that is elastically closed in its natural state. The tapered tube is hard and hollow. The minimum inner diameter of the tapered tube of the guide cannula seat anti-backflow plug is larger than the outer diameter of the puncture needle (allowing the puncture needle body to pass through). The minimum inner diameter of the tapered tube of the indwelling cannula seat anti-backflow plug is larger than the outer diameter of the guide cannula (allowing the guide cannula body to pass through). The head of the tapered tube is fitted into the corresponding round plug, and the corresponding slit is opened when the tapered tube is pushed forward.

[0015] The indwelling cannula seat is provided with an indwelling cannula extension tube. The inner cavity of the indwelling cannula seat is connected to the indwelling cannula extension tube used for infusion. A flow stop clamp can be installed on the indwelling cannula extension tube to facilitate timely stopping of infusion.

[0016] The puncture needle described in this application includes a puncture needle body, a puncture needle seat, and a puncture needle tail connected in sequence. The guide cannula includes a guide cannula body and a guide cannula seat. The indwelling cannula includes an indwelling cannula body and an indwelling cannula seat. The guide cannula seat is placed on the upper plane of the puncture needle tail, and the inner wall of the guide cannula seat mates with the outer wall of the puncture needle seat. The indwelling cannula seat is placed on the upper plane of the guide cannula seat, and the inner wall of the indwelling cannula seat mates with the outer wall of the guide cannula seat. This facilitates accurate positioning of each part of this application and prevents pathogens from easily invading.

[0017] The guiding cannula described in this application is provided with a T-shaped indwelling cannula fixing clip, and the indwelling cannula is provided with an indwelling cannula fixing platform. The middle part of the indwelling cannula fixing clip is connected to the guiding cannula, and the front part of the indwelling cannula fixing clip engages with the indwelling cannula fixing platform to hook the indwelling cannula fixing platform. The purpose is to prevent relative displacement between the indwelling cannula and the guiding cannula when the entire medical puncture needle needs to be appropriately retracted during the puncture process.

[0018] The puncture needle described in this application has a symmetrically arranged double-bevel structure at its head, making puncture more convenient.

[0019] This application allows for the design of matching puncture needles, guiding cannulas, and indwelling cannulas with varying inner and outer diameters according to clinical needs.

[0020] The head or the entire guide cannula described in this application may be made of an elastic material, which allows for slight bending to guide the indwelling cannula into the patient's blood vessels.

[0021] The indwelling cannula is equipped with an indwelling cannula extension tube, and the inner cavity of the indwelling cannula is connected to the indwelling cannula extension tube used for infusion.

[0022] Compared with the prior art, this application has the following advantages and effects: simple structure, relatively easy to enter blood vessels, convenient for medical personnel to perform vascular puncture, high puncture success rate, good structural stability of the indwelling cannula, preventing patient blood from flowing out and causing contamination and / or preventing bacteria and foreign objects from entering the medical puncture needle. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the puncture needle in Embodiment 1 of this application.

[0024] Figure 2 This is a cross-sectional schematic diagram of the puncture needle in Embodiment 1 of this application.

[0025] Figure 3 This is a schematic diagram of the structure of the guide sleeve in Embodiment 1 of this application.

[0026] Figure 4 This is a cross-sectional schematic diagram of the guide sleeve in Embodiment 1 of this application.

[0027] Figure 5 This is a schematic diagram of the structure of the indwelling sleeve in Embodiment 1 of this application.

[0028] Figure 6 This is a cross-sectional schematic diagram of the indwelling sleeve in Embodiment 1 of this application.

[0029] Figure 7 This is a schematic diagram of the structure of the puncture needle, guide cannula, and indwelling cannula assembled in Embodiment 1 of this application.

[0030] Figure 8 yes Figure 7 A cross-sectional view.

[0031] Figure 9 This is a schematic diagram of another structure of the guide sleeve in Embodiment 1 of this application.

[0032] Figure 10 yes Figure 9 The diagram shows the structure of the guide cannula, indwelling cannula, and puncture needle after they are assembled.

[0033] Figure 11 This is a schematic diagram of the structure of Embodiment 2 of this application.

[0034] Figure 12 This is a schematic diagram of the puncture needle in Embodiment 2 of this application.

[0035] Figure 13 This is a schematic diagram of the structure of the guide sleeve in Embodiment 2 of this application.

[0036] Figure 14 This is a schematic diagram of a structure of the indwelling sleeve in Embodiment 2 of this application.

[0037] Figure 15 This is a structural schematic diagram of Embodiment 3 of this application.

[0038] Figure 16 This is a schematic diagram of the puncture needle in Embodiment 3 of this application.

[0039] Figure 17 This is a schematic diagram of the structure of the indwelling sleeve in Embodiment 3 of this application.

[0040] Figure 18 This is another schematic diagram of the head of the puncture needle in an embodiment of this application.

[0041] Figure 19 This is a schematic diagram of the principle of the anti-backflow plug of this application (taking the guide sleeve anti-backflow plug as an example, the principle of the indwelling sleeve anti-backflow plug is the same).

[0042] Figure 20 for Figure 19 The diagram shows the anti-backflow plug being held open by the syringe head.

[0043] In the diagram: 1. Puncture needle 11. Puncture needle body 11. Puncture needle blood return groove 111. Puncture needle seat 12. Puncture needle seat upper surface 121. Puncture needle seat connector 122. Puncture needle tail 13. Puncture needle tail upper surface 131. Puncture needle tail breathable membrane 132. 2. Guide cannula 2. Guide cannula head 21. Guide cannula head cylindrical surface 211. Guide cannula head conical surface 212. Guide cannula body 22. Guide cannula seat 23. Guide cannula seat upper surface 24. 31. Guide cannula seat cavity 232. Guide cannula seat anti-backflow plug 233. Indwelling cannula fixing clamp 234. Indwelling cannula 3. Indwelling cannula head 31. Indwelling cannula body 32. Indwelling cannula seat 33. Indwelling cannula seat inner cavity upper plane 331. Indwelling cannula seat anti-backflow plug 332. Round plug 3321. Slit 33211. Tapered tube 3322. Indwelling cannula seat isolation plug 333. Indwelling cannula fixing platform 334. Indwelling cannula extension tube 34. Syringe 4. Detailed Implementation

[0044] The present application will be further described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are explanations of the present application, but the present application is not limited to the following embodiments. Figures 1-20 The left side is the head (front), and the right side is the tail (back).

[0045] Example 1:

[0046] See Figures 1-10 This application embodiment includes a puncture needle 1, a guiding cannula 2, and an indwelling cannula 3. The puncture needle 1 includes a puncture needle body 11, a puncture needle seat 12, and a puncture needle tail 13 connected in sequence. The guiding cannula 2 and the indwelling cannula 3 are both hollow through-structures. The puncture needle 1 and the guiding cannula 2 are fitted together, with the puncture needle body 11 inserted into the guiding cannula 2 and the guiding cannula seat 23 placed on the puncture needle seat 12. The indwelling cannula 3 is fitted onto the guiding cannula 2, forming a medical cannula needle consisting of the puncture needle 1, the guiding cannula 2, and the indwelling cannula 3 as a whole. Through the above design, this application enables the puncture needle + guiding cannula + indwelling cannula to be used together. Because a guiding cannula is added outside the puncture needle, and an indwelling cannula is fitted outside the guiding cannula, the diameter of the cavity inside the indwelling cannula is increased by one size relative to the outer diameter of the puncture needle (the indwelling cannula is one size larger than the diameter of the puncture needle). Generally, puncture is performed using a puncture needle, a guiding cannula, and an indwelling cannula. After the puncture is completed, the tip of the larger-sized indwelling cannula remains in the patient's blood vessel. The puncture needle and guiding cannula are then removed, and the indwelling cannula is used for subsequent infusion or pressure measurement. This expands the applicability of medical cannula needles, allows doctors to quickly complete punctures according to actual needs, improves the success rate of punctures, and reduces the possibility of needing to replace the puncture needle due to multiple unsuccessful punctures.

[0047] The medical cannula needle tip to the outer side of the indwelling cannula in this application has a smooth structure (generally smooth is sufficient, without obvious protrusions or steps that may affect the puncture work).

[0048] The guide cannula seat 23 is placed on the upper plane 131 of the puncture needle tail, and the inner wall of the guide cannula seat 23 is engaged with the outer wall of the puncture needle seat 12. The indwelling cannula seat 33 is placed on the upper plane 231 of the guide cannula seat, and the inner wall of the indwelling cannula seat 33 is engaged with the outer wall of the guide cannula seat 23.

[0049] The guiding cannula 2 described in this application has two forms. One form of the guiding cannula 2 has a conical outer surface at the head 21, which facilitates skin puncture and entry into the blood vessel (see...). Figure 3 , Figure 4 Another type of small guide sleeve 2 has an outer peripheral surface of the guide sleeve head 21 formed by connecting the guide sleeve head cylindrical surface 211 and the guide sleeve head conical surface 212 from top to bottom.

[0050] The head 21 (or the entire guide cannula 2) described in this application is made of an elastic material, which facilitates slight bending to guide the indwelling cannula 3 into the patient's blood vessels.

[0051] Example 2:

[0052] See Figures 11-14 The main structure of Example 2 is the same as that of Example 1, with the main differences being:

[0053] The puncture needle 1 has a hollow puncture needle hub 12 at its tail end, which engages with the head of the puncture needle tail 13, allowing the puncture needle tail 13 to be removed. The inner cavity of the puncture needle hub 122 mates with the outer diameter of the syringe head, allowing the syringe to be connected to flush the puncture needle or to aspirate to determine whether the puncture needle has entered the patient's blood vessel.

[0054] The puncture needle tail 13 can also be provided with a puncture needle tail permeable membrane 132, which prevents the patient's blood from not flowing out when the puncture needle body does not have a blood return groove, making it impossible to determine whether the puncture needle has entered the blood vessel; in addition, it prevents a large amount of blood from flowing out rapidly after the puncture needle is inserted into the patient's blood vessel, causing contamination (the anti-backflow plug has a similar function). After this structure is removed, the puncture needle seat connector 122 tail can be connected to a syringe.

[0055] The guide cannula seat 23 is equipped with a guide cannula anti-backflow plug 233 to prevent the patient's blood from being unable to flow out, making it impossible to determine whether the puncture needle has entered the blood vessel; it also prevents a large amount of blood from flowing out rapidly after the guide cannula 2 is inserted into the patient's blood vessel, causing contamination. The inner cavity at the tail of the guide cannula seat 23 can be matched with the outer diameter of the syringe head, allowing the syringe to be connected to flush the guide cannula or to aspirate to determine whether the guide cannula has entered the blood vessel.

[0056] The indwelling cannula seat 33 is equipped with an anti-backflow plug 332. This anti-backflow plug 332 prevents blood from being blocked, thus ensuring the indwelling cannula is in place; it also prevents large amounts of blood from flowing out rapidly after the cannula is inserted into the patient's blood vessel, thus avoiding contamination. The tail end of the indwelling cannula seat 33 mates with the outer diameter of the syringe head, allowing the syringe to be connected to flush the indwelling cannula or aspirate to determine if the cannula is in place.

[0057] The guide cannula 2 is equipped with a T-shaped indwelling cannula fixing clip 234, and the indwelling cannula 3 is equipped with an indwelling cannula fixing platform 234. The middle part of the indwelling cannula fixing clip 234 is connected to the guide cannula 2, and the front part of the indwelling cannula fixing clip 234 cooperates with and hooks onto the indwelling cannula fixing platform 234. The purpose is to prevent relative displacement (misalignment) between the indwelling cannula 3 and the guide cannula 2 when the entire medical puncture needle needs to be retracted appropriately during the puncture process. When it is necessary to release the indwelling cannula 3, simply press the rear part of the fixing clip 234 inward.

[0058] Example 3:

[0059] See Figures 15-17 The main structure of Example 3 is the same as that of Example 2, with the main differences being:

[0060] The puncture needle 1 consists only of the puncture needle body 11 and the puncture needle seat 12. The puncture needle body 11 is provided with a blood return groove 111. The outer diameter of the puncture needle body 11 is smaller than the inner diameter of the guide cannula body 22, which allows the patient's blood to flow through the blood return groove 111 into the space between the puncture needle body 11 and the guide cannula 2 (the blood flows out of the blood return groove and into the space between the inner wall of the puncture needle body and the guide cannula). This allows the doctor to directly observe the blood flow from the outside of the guide cannula 2 and the indwelling cannula 3 (both of which are transparent or semi-transparent) and promptly determine whether the puncture needle 1 has entered the patient's blood vessel.

[0061] The inner cavity of the indwelling cannula seat 33 can also be provided with an indwelling cannula seat isolation plug 333, which is made of soft elastic material. An indwelling cannula extension tube 34 can also be provided on the indwelling cannula 3, with the inner cavity of the indwelling cannula 3 connected to the indwelling cannula extension tube 34 used for infusion. A flow-stopping clamp can be provided on the indwelling cannula extension tube 34 for convenient and timely stopping of infusion. When the puncture needle 1 and the guiding cannula 2 are withdrawn, the indwelling cannula seat isolation plug 333 elastically retracts, sealing the indwelling cannula seat 33. At this time, the indwelling cannula seat anti-backflow plug 332 is not required. Whether the patient's blood flows to the indwelling cannula extension tube 34 can be used to determine whether the head of the indwelling cannula 3 has entered the patient's blood vessel.

[0062] The head of the puncture needle body 11 can be provided with a symmetrically configured double bevel structure 112, making puncture more convenient.

[0063] The anti-backflow plugs for guide sleeve seats and indwelling sleeve seats described in this application have the same structure. The principle of the anti-backflow plug is explained below using the anti-backflow plug for guide sleeve seats as an example:

[0064] The guide cannula anti-backflow plug 233 consists of a round plug 2331 and a tapered tube 2332, and is installed on the corresponding guide cannula seat. The round plug 2331 is made of a soft, elastic material and has a naturally elastically closed slot (a slot 23311) that allows a fine needle, such as a puncture needle, to pass through. Under normal conditions, blood will not flow out through the round plug 2331. The tapered tube 2332 is rigid and hollow, allowing the puncture needle to pass through. The head of the tapered tube 2332 is fitted inside the round plug 2331. When the tapered tube 2332 is pushed forward by external force (e.g., by the head of a syringe 4), the slot 33211 opens. (See also...) Figure 19 , Figure 20 At this time, intravenous infusion can be administered.

Claims

1. A medical trocar comprising a puncture needle, a remaining cannula, characterized in that: The puncture needle comprises a puncture needle body and a puncture needle seat connected in sequence, and the guide sleeve, the indwelling sleeve are hollow through structures.

2. The medical trocar of claim 1 wherein: The puncture needle is provided with a backflow display structure.

3. The medical trocar of claim 2 wherein: The backflow display structure comprises a backflow groove on the puncture needle body, and the guide sleeve and the indwelling sleeve are made of transparent or translucent materials and have an outer diameter smaller than an inner diameter of the guide sleeve.

4. The medical trocar of claim 1 wherein: The medical cannula needle is provided with a blood spill-proof structure.

5. The medical trocar of claim 4 wherein: The blood spill-proof structure adopts one or several of the following five structures: (1) the puncture needle comprises a puncture needle body, a puncture needle seat and a puncture needle tail connected in sequence, and the puncture needle tail is provided with a puncture needle tail air-permeable film; (2) the guide sleeve comprises a guide sleeve head, a guide sleeve body and a guide sleeve seat connected in sequence, and the guide sleeve seat is provided with a guide sleeve seat anti-backflow plug; (3) the indwelling sleeve comprises an indwelling sleeve head, an indwelling sleeve body and an indwelling sleeve seat connected in sequence, and the indwelling sleeve seat is provided with an indwelling sleeve seat anti-backflow plug; (4) the indwelling sleeve comprises an indwelling sleeve head, an indwelling sleeve body and an indwelling sleeve seat connected in sequence, and the indwelling sleeve seat is provided with an indwelling sleeve seat anti-backflow plug; (5) the blood spill-proof structure comprises an indwelling sleeve seat isolation plug, the indwelling sleeve comprises an indwelling sleeve head, an indwelling sleeve body and an indwelling sleeve seat connected in sequence, and the indwelling sleeve seat is provided with a soft and elastic indwelling sleeve seat isolation plug; The indwelling sleeve seat anti-backflow plug and the guide sleeve seat anti-backflow plug are composed of a round plug and a tapered tube, the round plug is made of soft and elastic material, the round plug is provided with a natural state elastic closed slit, the tapered tube is hard and hollow, the minimum inner diameter of the tapered tube of the guide sleeve seat anti-backflow plug is greater than the outer diameter of the puncture needle body, the minimum inner diameter of the tapered tube of the indwelling sleeve seat anti-backflow plug is greater than the outer diameter of the guide sleeve body, the tapered tube head is sleeved in the corresponding round plug, and the tapered tube is pushed to open the corresponding slit.

6. The medical trocar of claim 1 wherein: The puncture needle comprises a puncture needle body, a puncture needle seat and a puncture needle tail connected in sequence, the guide sleeve comprises a guide sleeve body and a guide sleeve seat, and the indwelling sleeve comprises an indwelling sleeve body and an indwelling sleeve seat, the guide sleeve seat is arranged on the upper plane of the puncture needle tail, the inner wall of the guide sleeve seat is matched with the outer wall of the puncture needle seat, and the indwelling sleeve seat is arranged on the upper plane of the guide sleeve seat.

7. The medical trocar of claim 1 wherein: The guide sleeve is provided with a T-shaped indwelling sleeve fixing clamp, the indwelling sleeve is provided with an indwelling sleeve fixing table, the middle part of the indwelling sleeve fixing clamp is connected with the guide sleeve, and the front part of the indwelling sleeve fixing clamp is matched and clamped with the indwelling sleeve fixing table.

8. The medical trocar of claim 1 wherein: The head of the puncture needle body is provided with symmetrically arranged double inclined surfaces.

9. The medical trocar of claim 1 wherein: The head of the guide sleeve or the whole guide sleeve is made of elastic material.

10. The medical trocar of claim 1 wherein: The indwelling cannula is provided with an indwelling cannula extension tube, and the inner cavity of the indwelling cannula is communicated with the indwelling cannula extension tube for transfusion.

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