Piercing trocar

Abstract

The present application relates to a kind of puncture trocar, including tearable sleeve and puncture needle arranged in tearable sleeve, axial self-locking connection mechanism is provided between the puncture needle and tearable sleeve, the axial self-locking connection mechanism includes annular boss and elastic clamping component, when puncture needle is inserted into tearable sleeve, elastic clamping component occurs elastic deformation and is clamped into the annular boss, axial rigid locking state is formed;In the axial rigid locking state, the puncture needle and the tearable sleeve have no relative displacement under the action of axial force;The advantages of the present application are: axial rigid locking state is formed by the axial self-locking connection mechanism arranged between puncture needle and tearable sleeve, and they have no relative retreat and no misalignment offset under the action of axial force, ensure that needle tip is always protruding from the front end of sleeve during puncture process, maintain the sharp puncture ability, puncture path is straight and accurate, greatly improve the stability and success rate of minimally invasive puncture operation.

Description

Technical Field

[0001] This invention relates to a puncture cannula. Background Technology

[0002] The trocar is a commonly used instrument in clinical medicine and a core instrument for establishing an operating channel in minimally invasive surgery. It usually consists of two parts: a tearable cannula and a puncture needle. When in use, the puncture needle pulls the tearable cannula into the target body cavity together. After the puncture needle is withdrawn, the tearable cannula remains in the body to form a minimally invasive operating channel. It can be removed later by tearing the tearable cannula, avoiding secondary tissue damage caused by pulling it out as a whole.

[0003] The following technical defects are commonly found in the use of conventional trocars in clinical practice: First, there is a lack of a stable axial locking structure between the trocar and the tearable cannula. When encountering tissue resistance during puncture, the trocar is prone to relative retraction or displacement with the tearable cannula, resulting in uneven puncture force, puncture position deviation, or even failure to penetrate the target tissue smoothly, affecting the accuracy of the surgical operation. Second, some trocars with simple locking structures have poor locking stability and lack an anti-accidental unlocking mechanism. During the operation, accidental contact with the unlocking component can easily cause premature locking failure, posing a surgical safety hazard. Third, the tearing structure of the tearable cannula is poorly designed, with uneven force on the tearing wings, causing jamming and deviation of the tearing path during the tearing process of the cannula body, easily resulting in cannula residue or unsmooth tearing, prolonging the operation time. Fourth, most trocars are not equipped with a sealing structure. After the trocar is withdrawn, gas or fluid inside the body cavity can easily leak out from the cannula channel, increasing the risk of postoperative infection and body cavity pressure imbalance. Summary of the Invention

[0004] The purpose of this invention is to solve the problem that the lack of a stable axial locking structure between the existing puncture needle and the tearable cannula leads to relative backward movement or displacement during use. This invention proposes a puncture cannula needle that forms an axially rigid locking state through an axial self-locking connection mechanism between the puncture needle and the tearable cannula. Under the action of axial force, there is no relative backward movement or misalignment between the two, ensuring that the needle tip always protrudes from the front end of the cannula during puncture, maintaining sharp puncture capability, and ensuring a straight and precise puncture path, which greatly improves the stability and success rate of minimally invasive puncture operations.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: a puncture cannula, comprising a tearable cannula and a puncture needle inserted inside the tearable cannula, wherein an axial self-locking connection mechanism is provided between the puncture needle and the tearable cannula, the axial self-locking connection mechanism comprising a mutually cooperating annular boss and an elastic locking component, wherein when the puncture needle is inserted into the tearable cannula, the elastic locking component undergoes elastic deformation and locks into the annular boss, forming an axially rigid locking state; in the axially rigid locking state, the puncture needle and the tearable cannula have no relative displacement under the action of axial force.

[0006] Preferably, the annular boss is disposed on the outer circumferential sidewall of the puncture needle, and the elastic snap-fit ​​assembly is disposed on the tearable sleeve.

[0007] Preferably, the elastic snap-fit ​​assembly includes at least two circumferentially distributed elastic cantilever beams, each elastic cantilever beam having an inwardly extending hook, one end of the annular boss having a vertical stop surface that abuts against the hook, and the other end of the annular boss having a guide ramp that guides the hook to slide over.

[0008] Preferably, the tearable sleeve is provided with an outwardly extending press-to-unlock wing, and the elastic cantilever beam is provided on the press-to-unlock wing. When the press-to-unlock wing is subjected to radially inward pressing force, the press-to-unlock wing drives the hook to expand outward to release the lock with the annular boss.

[0009] Preferably, the press-to-unlock wing is fitted with a sliding protective sleeve, which has a locked position covering the press-to-unlock wing and an unlock position exposing the press-to-unlock wing; in the locked position, the sliding protective sleeve blocks radial pressing force on the press-to-unlock wing.

[0010] Preferably, the outer wall of the press-to-unlock wing is provided with a guide groove, and the two ends of the guide groove are respectively provided with a first limiting pit and a second limiting pit. The sliding protective sleeve is provided with a limiting protrusion extending into the guide groove. The limiting protrusion is limited in the first limiting pit or the second limiting pit to fix the position of the sliding protective sleeve.

[0011] Preferably, the press-to-unlock wing and the tearable sleeve are an integral structure, and the press-to-unlock wing is provided with an anti-slip strip.

[0012] Preferably, the tearable sleeve is provided with a one-way sealing valve, which includes an open state and a closed state. When the puncture needle is in an axially rigid locked state, the one-way sealing valve is pushed to the open state by the thrust of the puncture needle. When the axially rigid locked state is unlocked and the puncture needle is pulled out of the tearable sleeve, the one-way sealing valve automatically resets to the closed state.

[0013] Preferably, the proximal end of the tearable sleeve is integrally formed with symmetrically distributed tearing wings; the connection root between the tearing wings and the sleeve body is provided with a V-shaped notch, the tip of the V-shaped notch pointing to the distal end of the tearable sleeve; the outer surface of the tearable sleeve is provided with easy-tear weakening lines along the axial direction.

[0014] Preferably, the puncture needle has a handhold at its tail end, which is located outside the tearable sheath; when the puncture needle is inserted into the tearable sheath, the end face of the handhold abuts against the tail end face of the tearable sheath to limit the insertion depth.

[0015] In summary, the advantages of this invention are as follows: By setting an axial self-locking connection mechanism between the puncture needle and the tearable cannula, which includes a cooperating annular boss and an elastic locking component, the elastic locking component engages with the annular boss to form an axially rigid locking state. This ensures that the puncture needle and the tearable cannula form a single unit, and the thrust is fully transmitted to the tip. Under the action of axial force, there is no relative backward movement or misalignment between the two, ensuring that the needle tip always protrudes from the front end of the cannula during puncture, maintaining sharp puncture capability, and ensuring a straight and precise puncture path. This avoids puncture failure and tissue damage caused by relative sliding of components, significantly improving the stability and success rate of minimally invasive puncture operations. Secondly, the elastic locking component eliminates the need for additional locking tools or operating steps; it automatically locks upon insertion, simplifying the preoperative assembly process and meeting the needs of rapid clinical operations. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the structure of a puncture cannula needle according to the present invention; Figure 2 for Figure 1 A magnified view of part A in the image; Figure 3 This is a schematic diagram of the installation structure of the sliding protective sleeve in this invention; Figure 4 This is a schematic diagram of the one-way sealing valve in the tearable sleeve of the present invention; Figure 5 This is an unfolded view of the tearable sleeve in this invention.

[0017] Figure label: 1. Tearable sleeve, 11. One-way sealing valve, 12. Tearable pull wing, 13. V-shaped notch, 14. Easy-tear weakening line, 2. Puncture needle, 21. Hand-held base, 3. Axial self-locking connection mechanism, 4. Annular boss, 41. Vertical stop surface, 42. Guide slope, 5. Elastic snap-fit ​​assembly, 51. Elastic cantilever beam, 52. Hook, 6. Press-to-unlock wing, 61. Guide groove, 62. First limit pit, 63. Second limit pit, 64. Anti-slip strip, 7. Sliding protective sleeve, 71. Limiting protrusion. Detailed Implementation

[0018] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, a puncture cannula includes a tearable cannula 1 and a puncture needle 2 inserted inside the tearable cannula 1. An axial self-locking connection mechanism 3 is provided between the puncture needle 2 and the tearable cannula 1. The axial self-locking connection mechanism 3 includes a mutually cooperating annular boss 4 and an elastic locking component 5. When the puncture needle 2 is inserted into the tearable cannula 1, the elastic locking component 5 undergoes elastic deformation and locks into the annular boss 4, forming an axially rigid locking state. In the axially rigid locking state, the puncture needle 2 and the tearable cannula 1 have no relative displacement under the action of axial force.

[0019] In this embodiment, axial force refers to the external force acting on the puncture needle or tearable cannula during use, attempting to induce axial relative movement between the two. Specifically, this axial force includes, but is not limited to, forces generated in the following situations: puncture operation force: When a medical professional holds the puncture needle and tearable cannula to puncture into a patient's blood vessel, the reaction resistance generated by the blood vessel wall and subcutaneous tissue against the needle tip is transmitted through the puncture needle to the axial self-locking connection mechanism, attempting to push the puncture needle backward (or forward) relative to the tearable cannula; operation force: The pushing or pulling force applied by the medical professional's hand to the puncture needle or tearable cannula when adjusting the needle insertion angle or depth; physiological pressure: The blood pressure within the blood vessel acting on the distal end of the puncture needle, attempting to push the puncture needle axially. It should be noted that "no relative displacement" under the "axial rigid locking state" means that the axial thrust that the axial self-locking connection mechanism can withstand is greater than the sliding friction between the puncture needle and the inner wall of the tearable cannula, and less than the unlocking force required to release the axial self-locking connection mechanism. In other words, during a normal puncture procedure, the conventional operating force (i.e., the axial force) is insufficient to overcome the mechanical interference between the elastic locking assembly and the annular boss, thereby ensuring that the puncture needle and the tearable cannula move synchronously as a whole, preventing accidental relative slippage or misalignment.

[0020] By setting an axial self-locking connection mechanism 3 between the puncture needle 2 and the tearable cannula 1, the axial self-locking connection mechanism 3 includes a mutually cooperating annular boss 4 and an elastic locking component 5. The elastic locking component 5 is locked into the annular boss 4 to form an axial rigid locking state. Therefore, it is ensured that the puncture needle 2 and the tearable cannula 1 form a whole, and the thrust is completely transmitted to the tip. Under the action of axial force, the two do not move backward or shift, ensuring that the needle tip always protrudes from the front end of the cannula during the puncture process, maintaining sharp puncture capability, and the puncture path is straight and accurate. This avoids puncture failure and tissue damage caused by relative sliding of components, and greatly improves the stability and success rate of minimally invasive puncture operation. Secondly, the setting of the elastic locking component 5 does not require additional locking tools or operation steps. It can be automatically locked upon insertion, simplifying the preoperative assembly process and adapting to the needs of rapid clinical operation.

[0021] The annular boss 4 is disposed on the outer circumferential side wall of the puncture needle 2, and the elastic snap-fit ​​component 5 is disposed on the tearable sleeve 1. Since the puncture needle 2 is usually made of metal, it is easier and cheaper to process the annular boss 4 than to process the elastic snap-fit ​​component 5, and it does not affect the rigidity of the needle body. By placing the elastic snap-fit ​​component 5 on the larger tearable sleeve 1, it is easier to injection mold and the production cost is reduced. The elastic locking assembly 5 includes at least two circumferentially distributed elastic cantilever beams 51. Each elastic cantilever beam 51 has an inwardly extending hook 52. One end of the annular boss 4 has a vertical stop surface 41 that abuts against the hook 52, and the other end of the annular boss 4 has a guide ramp 42 that guides the hook 52 to slide. By configuring the elastic locking assembly 5 with the structure of the elastic cantilever beams 51 and the hook 52, and because one end of the annular boss 4 has the vertical stop surface 41, the force acts directly on the vertical surface when subjected to axial force due to the contact between the vertical stop surface 41 and the hook 52, preventing the hook 52 from being pulled down. The force of release ensures the absolute reliability of the lock. Secondly, the setting of the guide slope 42 allows the hook 52 to slide along the guide slope 42 and automatically spring into the annular boss 4 when the puncture needle 2 is inserted, achieving automatic locking with a "click". The operator has clear auditory and tactile feedback, reducing the difficulty of assembly operation. Finally, at least two elastic cantilever beams 51 are set. In this embodiment, two elastic cantilever beams 51 are preferred and evenly distributed on the tearable sleeve 1, which can achieve uniform force distribution and avoid needle body deflection or jamming caused by single-point locking, further improving the locking state and making it less prone to unlocking when subjected to axial puncture thrust.

[0022] The tearable sleeve 1 is provided with an outwardly extending press-to-unlock wing 6. The elastic cantilever beam 51 is set on the press-to-unlock wing 6. When the press-to-unlock wing 6 is subjected to radially inward pressing force, the press-to-unlock wing 6 drives the hook 52 to expand outward to release the lock with the annular boss 4. By setting the elastic cantilever beam 51 on the press-to-unlock wing 6, in use, simply press the press-to-unlock wing 6 to drive the hook 52 to expand outward and unlock. The operation is simple and efficient, shortens the operation time, and is convenient for one-handed operation. The tearable sleeve 1 on the press-to-unlock wing 6 is set outward, which conforms to the ergonomic design. When the doctor presses, the force point is clear, the force is easy to exert, and the operation is not slipped. The unlocking force and the locking force are independent of each other. Press-to-unlock only controls the unlocking and does not affect the stability of the locked state. At the same time, the elastic cantilever beam 51 and the press-to-unlock wing 6 are linked, with high deformation synchronization and rapid unlocking response. It can be unlocked with one press without jamming or delay. A sliding protective sleeve 7 is fitted onto the press-to-unlock wing 6. The sliding protective sleeve 7 has a locked position covering the press-to-unlock wing 6 and an unlocked position exposing the press-to-unlock wing 6. In the locked position, the sliding protective sleeve 7 blocks radial pressing force on the press-to-unlock wing 6. Because the sliding protective sleeve 7 covers both the locked and unlocked positions of the press-to-unlock wing 6, during stages such as puncture and intraoperative positioning where unlocking is not required, the sliding protective sleeve 7 can be adjusted to the locked position, completely covering the press-to-unlock wing 6. Locking wing 6 prevents accidental external contact, eliminating premature unlocking due to instrument collisions or accidental hand contact during surgery. This avoids medical risks caused by locking failure during puncture. Moreover, during transportation, carrying, or non-operational states, the protective sleeve 7 covers the unlocking wing 6. Even if external pressure or impact occurs, the force will be applied to the protective sleeve 7 rather than the unlocking wing 6, completely eliminating the risk of accidental unlocking leading to needle loosening. In addition, it also prevents the surface of the unlocking wing 6 from being contaminated or accumulating dust. The unlocking position ensures the normal use of pressing the unlocking wing 6 without spatially interfering with the operation of pressing the unlocking wing 6.Specifically, the outer wall of the press-to-unlock wing 6 is provided with a guide groove 61, and the two ends of the guide groove 61 are respectively provided with a first limiting pit 62 and a second limiting pit 63. The sliding protective sleeve 7 is provided with a limiting protrusion 71 that extends into the guide groove 61. The limiting protrusion 71 is limited within the first limiting pit 62 or the second limiting pit 63 to fix the position of the sliding protective sleeve 7. Furthermore, by the limiting protrusion 71 cooperating with the first limiting pit 62 and the second limiting pit 63 respectively, the sliding protective sleeve 7 is precisely fixed, ensuring that the sliding protective sleeve 7 will not slide on its own under slight vibration, and always remains locked or In the unlocked state, the reliability is extremely high. Secondly, the guide groove 61 can ensure the movement trajectory of the limiting protrusion 71 and ensure the straightness of the sliding protective sleeve 7. In this embodiment, when the limiting protrusion 71 is inserted into the second limiting pit 63, the sliding protective sleeve 7 is in the locked position. When the limiting protrusion is inserted into the first limiting pit 62, the sliding protective sleeve 7 is in the unlocked position. In this embodiment, the sliding protective sleeve 7 is provided with a mounting hole for installing the limiting protrusion 71. After the limiting protrusion 71 passes through the mounting hole, it is inserted into the first limiting pit 62 or the second limiting pit 63. The installation and disassembly are convenient. In addition, the limiting protrusion 71 is provided with a pull ring, which makes it convenient for doctors to pull the limiting protrusion 71. The press-to-unlock wing 6 and the tearable sleeve 1 are an integral structure, and the press-to-unlock wing 6 is provided with an anti-slip strip 64. The integral structure of the press-to-unlock wing 6 and the tearable sleeve 1 simplifies the installation process between the press-to-unlock wing 6 and the tearable sleeve 1, improves the connection strength between the press-to-unlock wing 6 and the tearable sleeve 1, and is not easy to break or be damaged under repeated pressing or strong operation. Moreover, the integral molding reduces manufacturing costs and increases production efficiency. At the same time, there are no dead corners for bacterial residue at the splicing parts, which meets the requirements of sterile production of medical devices. The anti-slip strip 64 increases the friction between the hand and the unlock wing 6, and will not slip when pressing with medical gloves, making the force more stable and avoiding unlocking failure and operation delay due to glove slippage, further improving the convenience and reliability of operation.

[0023] The tearable sheath 1 is equipped with a one-way sealing valve 11, which has an open state and a closed state. When the puncture needle 2 is in an axially rigid locked state, the one-way sealing valve 11 is pushed to the open state by the thrust of the puncture needle 2. When the axially rigid locked state is unlocked and the puncture needle 2 is withdrawn from the tearable sheath 1, the one-way sealing valve 11 automatically resets to the closed state. The one-way sealing valve 11 is designed to automatically close when the puncture needle 2 is withdrawn, preventing the patient's blood from flowing out of the sheath, protecting medical staff from blood contamination, reducing the risk of cross-infection, and preventing air from entering the blood vessels in the closed state, thus improving the patient's safety. Finally, the one-way sealing valve 11 can automatically reset from the open state to the closed state without additional manual operation, improving work efficiency in emergency or busy clinical environments. In this embodiment, the one-way sealing valve 11 is a duckbill valve. The tearable sleeve 1 has symmetrically distributed tear-resistant wings 12 integrally formed at its proximal end. A V-shaped notch 13 is provided at the connection root between the tear-resistant wings 12 and the sleeve body, with the tip of the V-shaped notch 13 pointing towards the distal end of the tearable sleeve 1. The outer surface of the tearable sleeve 1 has an axially arranged easy-tear weakening line 14. By setting symmetrically distributed tear-resistant wings 12 at the proximal end of the tearable sleeve 1, uniform force distribution can be achieved, ensuring balanced force when pulled by both hands and avoiding tearing deviation caused by unilateral force. Furthermore, the integral forming of the tear-resistant wings 12 and the tearable sleeve 1 simplifies the installation process between them and improves the connection strength. Additionally, pointing the tip of the V-shaped notch 13 towards the distal end concentrates stress on the V-shaped notch when the wings 12 are pulled to both sides. The pointed tip can easily pierce the cannula wall to initiate tearing, solving the problem of traditional cannulas being "difficult to tear". The easy-tear weakening line 14 ensures that the tearable cannula 1 is torn in a straight line without jamming or skew, and without cannula fragments remaining in the body. After tearing, it can be withdrawn smoothly, avoiding secondary tissue damage caused by pulling out the cannula as a whole, reducing patient discomfort during the operation, and allowing for faster postoperative recovery.

[0024] The puncture needle 2 has a handle 21 at its tail end, which is located outside the tearable cannula 1. When the puncture needle 2 is inserted into the tearable cannula 1, the end face of the handle 21 abuts against the tail end face of the tearable cannula 1 to limit the insertion depth. The handle 21 is designed to facilitate the doctor's grip and application of force during puncture, ensuring that the doctor can better control the puncture force and direction, thus improving the accuracy of the operation. Secondly, by limiting the insertion depth through the abutment of the end face of the handle 21 against the tail end face of the tearable cannula 1, the maximum depth to which the puncture needle 2 enters the body is fixed, preventing the needle tip from piercing the posterior wall of the blood vessel or damaging deep nerves / tissues due to excessive force. Moreover, the exposed length of the needle tip is completely uniform each time it is assembled, eliminating the need for the doctor to manually adjust the depth, reducing operational errors, and adapting to standardized clinical operations.

[0025] In addition to the preferred embodiments described above, there are other embodiments of the present invention. Those skilled in the art can make various changes and modifications based on the present invention, and all such changes and modifications should fall within the scope defined by the appended claims, as long as they do not depart from the spirit of the present invention.

Claims

1. A puncture cannula, comprising a tearable cannula and a puncture needle inserted within the tearable cannula, characterized in that: An axial self-locking connection mechanism is provided between the puncture needle and the tearable cannula. The axial self-locking connection mechanism includes a mutually cooperating annular boss and an elastic locking component. When the puncture needle is inserted into the tearable cannula, the elastic locking component undergoes elastic deformation and locks into the annular boss, forming an axially rigid locking state. In the axially rigid locking state, the puncture needle and the tearable cannula have no relative displacement under the action of axial force.

2. The puncture cannula according to claim 1, characterized in that: The annular boss is disposed on the outer circumferential sidewall of the puncture needle, and the elastic snap-fit ​​assembly is disposed on the tearable sleeve.

3. The puncture cannula according to claim 2, characterized in that: The elastic snap-fit ​​assembly includes at least two circumferentially distributed elastic cantilever beams, each elastic cantilever beam having an inwardly extending snap hook. One end of the annular boss has a vertical stop surface that abuts against the snap hook, and the other end of the annular boss has a guide ramp that guides the snap hook to slide over.

4. The puncture cannula according to claim 3, characterized in that: The tearable sleeve is provided with an outwardly extending press-to-unlock wing, and the elastic cantilever beam is set on the press-to-unlock wing. When the press-to-unlock wing is subjected to radially inward pressing force, the press-to-unlock wing drives the hook to expand outward to release the lock with the annular boss.

5. The puncture cannula according to claim 4, characterized in that: The press-to-unlock wing is fitted with a sliding protective sleeve, which has a locking position that covers the press-to-unlock wing and an unlocking position that exposes the press-to-unlock wing; In the locked position, the sliding protective sleeve blocks radial pressing force on the press-to-unlock wing.

6. The puncture cannula according to claim 5, characterized in that: The outer wall of the press-to-unlock wing is provided with a guide groove, and the two ends of the guide groove are respectively provided with a first limiting pit and a second limiting pit. The sliding protective sleeve is provided with a limiting protrusion that extends into the guide groove. The limiting protrusion is limited in the first limiting pit or the second limiting pit to fix the position of the sliding protective sleeve.

7. The puncture cannula according to claim 6, characterized in that: The press-to-unlock wing and the tearable sleeve are an integral structure, and the press-to-unlock wing is provided with anti-slip strips.

8. The puncture cannula according to claim 1, characterized in that: The tearable sleeve is equipped with a one-way sealing valve, which has an open state and a closed state. When the puncture needle is in an axially rigid locked state, the one-way sealing valve is pushed to the open state by the thrust of the puncture needle. When the axially rigid locked state is unlocked and the puncture needle is pulled out of the tearable sleeve, the one-way sealing valve automatically resets to the closed state.

9. The puncture cannula according to claim 1, characterized in that: The proximal end of the tearable sleeve is integrally formed with symmetrically distributed tearing wings; the root of the tearing wings and the sleeve body is provided with a V-shaped notch, the tip of the V-shaped notch pointing to the distal end of the tearable sleeve; the outer surface of the tearable sleeve is provided with easy-tear weakening lines along the axial direction.

10. A puncture cannula according to claim 1, characterized in that: The puncture needle has a handhold at its tail end, which is located outside the tearable sheath. When the puncture needle is inserted into the tearable sheath, the end face of the handhold abuts against the tail end face of the tearable sheath to limit the insertion depth.

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