Safe retraction mechanism for alimentary canal puncture needle

Abstract

The invention relates to the technical field of medical instruments, and discloses a safe retraction mechanism for a digestive tract puncture needle. The mechanism takes a hollow tube body as a core base body, one axial end of the hollow tube body is fixedly connected with a flexible guide tube, and one radial side is fixedly connected with a medical functional catheter; a puncture assembly is slidably installed in the hollow pipe body, an axial guide groove is formed in the inner wall, and an axial boss on the peripheral wall of the puncture base is matched with the guide groove. The puncture assembly comprises a puncture base and a puncture needle body fixed to one end of the puncture base, and the needle body is arranged in the flexible guide pipe in a penetrating mode and forms a support. A pull-back rod is fixed on the puncture base, one end of the pull-back rod extends out of the hollow tube body, and a rod body is sleeved with a pre-stretching pull-back spring to provide retraction power; the pull-back rod is assembled with the recovery mechanism and comprises a locking base, a clamping assembly and a retraction triggering piece. After puncture is completed, the clamping assembly is unlocked and linkage is released through the pull-back spring, rapid retraction of the needle point is achieved, the end opening of the guide pipe is sealed in cooperation with the elastic contraction ring, dual protection is formed, puncture wounds are effectively avoided, and medical safety specifications are met.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a safe retraction mechanism for a digestive tract puncture needle. Background Technology

[0002] In the process of gastrointestinal puncture diagnosis and treatment, the core problem of traditional puncture needles is that after the puncture is completed, the needle tip lacks a reliable retraction and sealing protection structure: most puncture needles have the needle tip directly exposed after puncture, or are only covered by a simple sheath, which cannot achieve rapid and stable needle tip retraction and port sealing.

[0003] This not only easily leads to needle pricks for medical staff during subsequent procedures, but also may cause cross-contamination due to bodily fluids contaminated with the needle tip, seriously threatening the safety of medical procedures and failing to meet the core clinical need for safety protection of puncture instruments. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a safe retraction mechanism for a digestive tract puncture needle.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A safe retraction mechanism for a gastrointestinal puncture needle includes a hollow tube body. A flexible guide tube is fixedly connected to the upper end of the hollow tube body, and a medical functional catheter is fixedly connected to one side of the hollow tube body. A puncture assembly is slidably installed inside the hollow tube body. An axial guide groove is provided on the inner wall of the hollow tube body, and an axial boss adapted to the guide groove is provided on the outer peripheral wall of the puncture base. The puncture assembly is installed in the hollow tube body through the sliding fit between the boss and the guide groove. The puncture assembly includes a puncture base, and a puncture needle body is fixedly installed at one end of the puncture base. The puncture needle body passes through the flexible guide tube and provides support thereto. A pull-back rod is fixedly installed on the puncture base, and one end of the pull-back rod extends out of the hollow tube body. A pull-back spring in a pre-stretched state is sleeved on the pull-back rod. A retrieval mechanism is also provided on the pull-back rod. The retrieval mechanism includes a locking base fixedly connected to the pull-back rod, a locking assembly disposed between the locking base and the inner wall of the hollow tube body, and a retraction trigger for releasing the locking state of the locking assembly.

[0006] Preferably, a sliding seat is slidably fitted onto one end of the pull-back rod extending out of the hollow tube, and the two ends of the pull-back spring are respectively fixedly connected to the sliding seat and the locking base, and the sliding seat and the pull-back rod form an axial sliding fit.

[0007] Preferably, the locking base is fixed to one end of the pull-back rod near the puncture base, and the engaging assembly includes an engaging member disposed between the locking base and the hollow tube. The retraction trigger is disposed on the radially outer side of the hollow tube corresponding to the engaging member, and the engaging member is driven to disengage from the locking base by radial movement.

[0008] Preferably, the locking component includes a locking groove formed in the inner wall of the hollow tube, a locking block embedded in the locking groove, and a return spring connected to the bottom of the locking groove via a medical-grade non-toxic spring. Under normal conditions, the return spring pushes the locking block to extend towards the axis of the hollow tube.

[0009] Preferably, the locking block has a right-angled triangle cross-section, the locking base has a first locking groove corresponding to the locking block, and the hollow tube has a second through hole coaxial with the first locking groove. The locking groove extends through the hollow tube to the second through hole, and the locking block can extend through the second through hole into the hollow tube and fit with the first locking groove. In the initial state, the hypotenuse of the right-angled triangle of the locking block faces the puncture direction of the puncture needle extending out of the hollow tube, and its right-angled side forms a surface contact with the sidewall of the first locking groove.

[0010] Preferably, the retraction trigger includes a trigger bracket, and the outer wall of the hollow tube has an axially extending receiving groove. The trigger bracket is embedded in the receiving groove and forms an axial sliding fit with the receiving groove. A pressing protrusion corresponding to the locking block is fixedly installed on the trigger bracket. The contact surface of the pressing protrusion is an inclined surface that fits against the inclined side of the locking block. When the trigger bracket is pushed in the direction of the hollow tube axis, the pressing protrusion abuts against the inclined side of the locking block through the inclined surface, driving the locking block to disengage from the first locking groove and retract into the locking groove. The preload of the pull spring drives the puncture needle body to retract.

[0011] Preferably, the retraction trigger further includes a trigger rod fixedly connected to the trigger bracket. The trigger rod is symmetrically arranged on both radial sides of the hollow tube body. The trigger rod and the hollow tube body form a sliding fit along its axial direction. An anti-slip protrusion is fixedly connected to the end of the trigger rod.

[0012] Preferably, a sealing end cap is fitted onto the end of the hollow tube that is away from the flexible guide tube, the pull-back rod passes through the sealing end cap and forms a sliding seal connection with the sealing end cap, and a needle tip protection component for needle tip retraction protection is installed on the sealing end cap.

[0013] Preferably, the needle tip protection assembly includes a protective sleeve rotatably mounted on a sealing end cap. The protective sleeve is fitted over the outside of the hollow tube and is made of medical-grade silicone rubber. The inner wall of the protective sleeve has a circumferential locking rib, and the outer circumferential wall of the sealing end cap has a locking groove that matches the locking rib. An elastic contraction ring is fixedly fitted at the end of the protective sleeve near the flexible guide tube. The elastic contraction ring is normally fitted over the outside of the hollow tube and is in a pre-stretched state. After rotating the protective sleeve to unlock the locking rib by disengaging it from the locking groove, the protective sleeve is pulled away from the flexible guide tube to release its support for the elastic contraction ring. The elastic contraction ring quickly contracts through its own elasticity to wrap around the end of the flexible guide tube, achieving sealing protection after the needle tip retracts.

[0014] The present invention has the following beneficial effects: 1. The puncture needle safety retraction mechanism proposed in this invention can achieve rapid retraction of the needle tip after puncture by unlocking the locking component and releasing the pull-back spring. Combined with the elastic contraction ring sealing the flexible guide tube port, it forms double safety protection, effectively avoiding the risk of puncture injury and cross-contamination caused by exposed needle tip, and fully meets the safety requirements of medical operation.

[0015] 2. The puncture needle safety retraction mechanism proposed in this invention features a symmetrical layout design for the trigger rod, combined with an axial sliding unlocking method, which ensures balanced force distribution and effortless operation. The protective sleeve adopts a dual-action design of rotational unlocking and axial pulling, making the operation process simple and efficient, adaptable to the needs of rapid clinical operations, and effectively reducing the operational difficulty for medical staff.

[0016] 3. The puncture needle safety retraction mechanism proposed in this invention can ensure the coaxiality of the puncture and retraction process through the precise cooperation of the guide groove and the boss, ensuring smooth operation; the reset spring made of medical stainless steel and the pull-back spring in the pre-stretched state provide stable power for the operation of the mechanism; the protective components made of medical silicone rubber have excellent biocompatibility; the overall structure is compact and has a long service life, and can stably adapt to the complex use environment of gastrointestinal puncture. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the puncture needle safety retraction mechanism proposed in this invention; Figure 2 This is a schematic diagram of the internal structure of the puncture needle safety retraction mechanism proposed in this invention; Figure 3 In this invention Figure 2 An enlarged schematic diagram of part A in the middle; Figure 4 This is a partial schematic diagram of the locking base proposed in this invention; Figure 5This is a partial schematic diagram of the trigger bracket proposed in this invention; Figure 6 This is a schematic diagram of the internal structure of the locking assembly proposed in this invention; Figure 7 This is a three-dimensional schematic diagram of the locking block proposed in this invention; Figure 8 A partial schematic diagram of the needle tip protection component proposed in this invention.

[0018] In the diagram: 1. Hollow tube body; 2. Flexible guide tube; 3. Medical functional catheter; 4. Puncture assembly; 41. Puncture base; 42. Puncture needle body; 5. Pull-back rod; 6. Retrieval mechanism; 61. Locking base; 7. Engaging assembly; 63. Sliding seat; 64. Pull-back spring; 71. Engaging part; 72. Retraction trigger; 711. Engaging block; 712. Engaging groove; 713. First slot; 714. Second through hole; 721. Trigger bracket; 722. Receiving groove; 723. Extrusion protrusion; 724. Trigger rod; 725. Anti-slip protrusion; 8. Sealing end cap; 9. Needle tip protection assembly; 91. Protective sleeve; 92. Elastic contraction ring. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0021] Reference Figures 1-8 As shown, a safe retraction mechanism for a digestive tract puncture needle is disclosed. The device includes a hollow tube 1, a flexible guide tube 2, a medical functional catheter 3, and a puncture assembly 4. The mechanism uses the hollow tube 1 as the core mounting base. The flexible guide tube 2 is fixedly connected to one axial end (the end extending along the length of the hollow tube 1). A medical functional catheter 3 for assisting diagnosis and treatment is fixedly connected to one side of the hollow tube 1. A strip-shaped guide groove is formed on the inner wall of the hollow tube 1 along the axial direction. The puncture assembly 4 forms a sliding fit with the guide groove through an axial boss integrally formed on the outer peripheral wall of its puncture base 41, thereby allowing it to be stably slidably installed inside the tube along the axial direction of the hollow tube 1.

[0022] In this embodiment, the puncture assembly 4 consists of a puncture base 41 and a puncture needle body 42 fixedly installed at one end of the base. The puncture needle body 42 is coaxially inserted inside the flexible guide tube 2, which can not only realize the puncture action along the extension direction of the flexible guide tube 2, but also form radial support for the flexible guide tube 2 to ensure the guiding stability during the puncture process.

[0023] A pull-back rod 5 is fixedly installed at one end of the puncture base 41 away from the puncture needle body 42. The other end of the pull-back rod 5 extends out of the hollow tube body 1 along the axial direction. A pull-back spring 64 in a pre-stretched state is sleeved on the outside of the pull-back rod 5. The pull-back spring 64 provides retraction power for the puncture needle body 42. The pull-back rod 5 is also equipped with a retrieval mechanism 6 for locking and unlocking the puncture needle body 42. The retrieval mechanism 6 includes a locking base 61 fixedly connected to the outer peripheral wall of the pull-back rod 5, a locking component 7 clamped between the locking base 61 and the inner wall of the hollow tube body 1, and a retraction trigger 72 corresponding to the locking component 7 for releasing its locking state. Through precise positional matching and connection, the components work together to achieve the safe puncture and reliable retraction function of the puncture needle body 42.

[0024] Reference Figure 2 As shown, an annular sliding seat 63 is slidably sleeved on the outer peripheral wall of the free end of the pull-back rod 5 extending axially out of the hollow tube 1. The inner hole of the sliding seat 63 is adapted to the outer peripheral wall of the pull-back rod 5 and forms an axial sliding fit, which can smoothly slide along the axial direction of the pull-back rod 5. The pull-back spring 64 is coaxially sleeved on the rod section of the pull-back rod 5 located between the sliding seat 63 and the locking base 61. Its two ends are respectively fixedly connected to the inner end face of the sliding seat 63 and the outer end face of the locking base 61. The locking base 61 is fixedly installed at the end of the pull-back rod 5 near the puncture base 41. The axial sliding fit between the sliding seat 63 and the pull-back rod 5 provides a matching space for the extension and retraction of the pull-back spring 64, so that the pull-back spring 64 always maintains a pre-stretched state, thereby continuously providing stable power for the retraction of the puncture needle body 42.

[0025] Reference Figure 2 As shown, the annular locking base 61 is fixed to one end of the pull-back rod 5 near the puncture base 41 by welding. An annular gap is reserved between its outer peripheral wall and the inner wall of the hollow tube 1 to accommodate the installation of the locking assembly 7, forming a basic installation space for locking and engaging. The locking assembly 7 is the core component for fixing the locking base 61 and the hollow tube 1. It is sandwiched between the outer peripheral wall of the locking base 61 and the inner wall of the hollow tube 1. One end of the locking member 71 is elastically connected or slidably engaged with the hollow tube 1, and the other end can be engaged and limited with the corresponding structure of the locking base 61, thereby stably locking the locking base 61 and the pull rod 5 and the puncture assembly 4 fixed thereto in the preset puncture working position. In this embodiment, the retraction trigger 72 used to release the locking state adopts a structural design that is precisely aligned with the locking member 71. It is assembled as a whole on the radially outer side of the hollow tube 1 (i.e., the outer wall area perpendicular to the axis of the hollow tube 1). Its inner working end passes through the corresponding mounting structure of the hollow tube 1 and forms a contact fit with the outer end of the locking member 71. When a pushing action is applied to the retraction trigger 72 along the radial direction of the hollow tube 1 towards the axis, the retraction trigger 72 can directly drive the locking member 71 to generate axial displacement through its inner working end, so that it is disengaged from the locking limit with the locking base 61, thereby releasing the locking state and providing unlocking conditions for the subsequent retraction of the puncture needle body 42 by the pull-back spring 64.

[0026] Reference Figures 3-7 As shown, the engaging component 71 includes an engaging groove 712, an engaging block 711, and a return spring. The engaging groove 712 is a groove structure radially opened along the inner wall of the hollow tube 1. The size of the groove cavity is adapted to the assembly requirements of the engaging block 711 and the return spring, forming the basic mounting carrier of the engaging component 71. The engaging block 711 is a block structure adapted to the engaging groove 712. It is embedded in the engaging groove 712 and forms a radial sliding fit with the groove wall. It can extend along the engaging groove 712 towards the axis of the hollow tube 1 or retract into the groove. The return spring is made of medical-grade stainless steel and is adapted to the depth of the locking groove 712 and the length of the locking block 711. One end of the return spring is fixedly connected to the bottom of the locking groove 712, and the other end is fixedly connected to the inner end of the locking block 711, forming an elastic drive structure. Under normal conditions, the return spring is always in a naturally extended or slightly pre-compressed state. Through its own elastic force, it continuously applies a thrust towards the axis of the hollow tube 1 to the locking block 711, pushing the locking block 711 to stably extend out of the locking groove 712 and form a locking limit with the locking base 61, thereby achieving relative fixation between the locking base 61 and the hollow tube 1, and providing stable support for the puncture working posture of the puncture assembly 4.

[0027] Referring to Figure 7, the locking block 711 adopts a block structure with a right-angled triangular cross-section. A first groove 713, matching the shape of the locking block 711, is provided on the outer peripheral wall of the locking base 61 at a position corresponding to the locking block 711. The groove wall size of the first groove 713 matches the length of the right-angled side of the locking block 711, providing a structural basis for surface contact locking. A second through hole 714, coaxially corresponding to the first groove 713, is provided on the wall of the hollow tube 1. The second through hole 714 penetrates the tube wall radially along the hollow tube 1 and communicates with the locking groove 712 of the locking assembly 7. The locking groove 712 extends axially inward along the hollow tube 1 and penetrates to the second through hole 714, forming a sliding channel for the locking block 711. In this embodiment, the locking groove 712... The second through hole 714 and the first slot 713 are coaxially aligned to ensure that the locking block 711 can smoothly pass through the second through hole 714 and extend into the hollow tube 1 in the radial direction, and precisely fit into the first slot 713 of the locking base 61. When the puncture component 4 is in the preset puncture working position, the hypotenuse of the right triangle of the locking block 711 faces the puncture direction of the puncture needle 42 extending into the hollow tube 1, and its right-angled side perpendicular to the puncture direction is tightly fitted with the side wall of the first slot 713 to form a stable surface contact locking structure. This locking method restricts the axial displacement of the locking base 61 and the pull rod 5 fixed thereto, as well as the puncture component 4, in the retraction direction, thereby locking the puncture component 4 in the working position and ensuring the stability of the puncture process.

[0028] Reference Figure 4 As shown, the retraction trigger 72 includes a trigger bracket 721, a receiving groove 722, and a pressing protrusion 723. The outer wall of the hollow tube 1 is provided with a receiving groove 722 extending along the tube axis at the axial distribution position corresponding to the engaging part 71. The trigger bracket 721 is embedded in the receiving groove 722 and forms a tight axial sliding fit with the groove wall, ensuring that the trigger bracket 721 can only slide smoothly along the axial direction of the hollow tube 1. On the inner wall of the trigger bracket 721 facing the axis of the tube, there are pressing protrusions 723 that correspond one-to-one with the locking block 711. The contact surface of the pressing protrusion 723 is an inclined surface that fits against the inclined side of the locking block 711, and the pressing protrusion 723 and the locking block 711 are precisely aligned along the axial direction. When the trigger rod 724 is pushed axially in the opposite direction of puncture, the trigger rod 724 drives the trigger bracket 721 to slide axially along the receiving groove 722. The squeezing protrusion 723 abuts against the inclined side of the locking block 711 through the inclined surface, converting the axial thrust into a radial force that drives the locking block 711 to retract into the locking groove 712, causing the locking block 711 to disengage from the first locking groove 713. The preload of the pull spring 64 is then released, which drives the puncture needle body 42 to retract, realizing the safe reset function after puncture.

[0029] Reference Figure 4The retraction trigger 72 also includes a trigger rod 724 and an anti-slip protrusion 725. The trigger rod 724 is connected to both ends of the trigger bracket 721 by a fixed connection. Its whole structure is rod-shaped and is symmetrically distributed on both sides of the tube body along the radial direction of the hollow tube body 1 to form a balanced operation layout. The outer end of the trigger lever 724, away from the trigger bracket 721, is fixedly connected to an anti-slip protrusion 725. The anti-slip protrusion 725 adopts a raised structure design and has anti-slip texture on the surface, which increases the friction when the operator presses and provides a clear operating feel.

[0030] Reference Figure 8 A sealing end cap 8 adapted to the tube port is fitted at the axial end of the hollow tube 1 away from the flexible guide tube 2. The sealing end cap 8 is fastened to the end of the hollow tube 1 by a fixed connection. The pull rod 5 passes through the central through hole of the sealing end cap 8 along the axial direction and forms a sliding sealing connection with the inner wall of the through hole. This ensures the smooth axial sliding of the pull rod 5 and prevents contamination or body fluid from seeping into the tube. A needle tip protection component 9 for needle tip retraction protection is also rotatably installed on the outer peripheral wall of the sealing end cap 8. The protective component is mainly composed of a protective sleeve 91 made of medical-grade silicone rubber. The protective sleeve 91 has a cylindrical structure and is fitted onto the outside of the hollow tube 1. Its inner wall is provided with a circumferential locking rib. Correspondingly, the outer peripheral wall of the sealing end cap 8 is provided with an annular locking groove that matches the shape and size of the locking rib. The locking state of the protective sleeve 91 is achieved by the engagement of the rib and the locking groove. An elastic shrink ring 92 is fixedly fitted onto the axial end of the protective sleeve 91 near the flexible guide tube 2. Under normal conditions, the elastic shrink ring 92 is coaxially fitted onto the outside of the hollow tube 1 and is in a pre-stretched state. Its inner diameter is slightly smaller than the outer diameter of the flexible guide tube 2 and is precisely aligned axially with the port position of the flexible guide tube 2. In this embodiment, the protective sleeve 91 achieves circumferential rotation through the rotational engagement of its inner wall and the outer peripheral wall of the sealing end cap 8. The engagement of the locking rib and the locking groove can limit its axial displacement. The elastic shrink ring 92 is fixed to the end of the protective sleeve 91 by interference fit or adhesive bonding to ensure the stability of tensile force transmission. After the puncture needle body 42 retracts, rotate the protective sleeve 91 to unlock the circumferential locking rib from the locking groove of the sealing end cap 8. Then, pull the protective sleeve 91 in the axial direction away from the flexible guide tube 2 to separate it from the hollow tube body 1. At this time, the elastic contraction ring 92 gets rid of the support constraint of the hollow tube body 1 and rapidly contracts radially through its own elastic potential energy, tightly wrapping the port of the flexible guide tube 2. The needle tip retracted into the tube is completely sealed in the sealing space formed by the flexible guide tube 2 and the contraction ring, achieving safe sealing protection after the needle tip retracts, avoiding the risk of contamination or puncture caused by the needle tip being exposed.

[0031] Working principle: In the initial state, the pullback spring 64 is pre-stretched, and the locking block 711 extends under the action of the return spring and engages with the locking base 61 in the slot, locking the puncture assembly 4 in the working position.

[0032] During puncture, the puncture needle body 42 extends along the flexible guide tube 2 to complete the operation; after puncture, the axial push of the trigger rod 724 drives the trigger bracket 721 to slide, the squeezing protrusion 723 drives the locking block 711 to radially retract and unlock through the inclined surface, and the pull spring 64 releases the pre-tension force to pull the puncture needle body 42 back into the tube.

[0033] Finally, rotate the protective sleeve 91 to unlock it and pull it away from the guide tube. The elastic shrink ring 92 will quickly shrink after disengaging from the support, wrapping around the port of the flexible guide tube 2 to achieve needle tip sealing protection and avoid contamination or puncture.

[0034] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A safe retraction mechanism for a gastrointestinal puncture needle, comprising a hollow tube (1), wherein a flexible guide tube (2) is fixedly connected to the upper end of the hollow tube (1), a medical functional catheter (3) is fixedly connected to one side of the hollow tube (1), a puncture assembly (4) is slidably installed inside the hollow tube (1), an axial guide groove is provided on the inner wall of the hollow tube (1), an axial boss adapted to the guide groove is provided on the outer peripheral wall of the puncture base (41), and the puncture assembly (4) is installed inside the hollow tube (1) through the sliding fit between the boss and the guide groove, characterized in that: The puncture assembly (4) includes a puncture base (41), one end of which is fixedly mounted with a puncture needle body (42), which passes through the flexible guide tube (2) and provides support thereto; A pull rod (5) is fixedly installed on the puncture base (41). One end of the pull rod (5) extends out of the hollow tube (1). A pull spring (64) in a pre-stretched state is sleeved on the pull rod (5). The pull-back rod (5) is also provided with a recycling mechanism (6). The recycling mechanism (6) includes a locking base (61) fixedly connected to the pull-back rod (5), a locking assembly (7) located between the locking base (61) and the inner wall of the hollow tube (1), and a retraction trigger (72) for releasing the locking state of the locking assembly (7).

2. The safety retraction mechanism for a digestive tract puncture needle according to claim 1, characterized in that: The pull rod (5) extends out of the hollow tube (1) and is slidably fitted with a sliding seat (63). The two ends of the pull spring (64) are fixedly connected to the sliding seat (63) and the locking base (61) respectively, and the sliding seat (63) and the pull rod (5) form an axial sliding fit.

3. The safety retraction mechanism for a digestive tract puncture needle according to claim 2, characterized in that: The locking base (61) is fixed at one end of the pull-back rod (5) near the puncture base (41). The engaging assembly (7) includes an engaging member (71) disposed between the locking base (61) and the hollow tube (1). The retraction trigger (72) is disposed on the radial outer side of the hollow tube (1) corresponding to the engaging member (71), and drives the engaging member (71) to disengage from the locking base (61) through radial movement.

4. The safety retraction mechanism for a digestive tract puncture needle according to claim 3, characterized in that: The locking component (71) includes a locking groove (712) opened on the inner wall of the hollow tube (1), a locking block (711) embedded in the locking groove (712), and the locking block (711) is connected to the bottom of the locking groove (712) by a reset spring made of medical grade non-toxic spring. Under normal conditions, the reset spring pushes the locking block (711) to extend in the direction of the axis of the hollow tube (1).

5. The safety retraction mechanism for a digestive tract puncture needle according to claim 4, characterized in that: The cross-section of the locking block (711) is a right triangle. The locking base (61) is provided with a first slot (713) corresponding to the locking block (711). The hollow tube (1) is provided with a second through hole (714) coaxial with the first slot (713). The locking groove (712) extends through the hollow tube (1) to the second through hole (714). The locking block (711) can extend through the second through hole (714) into the hollow tube (1) and be adapted to the first slot (713). In the initial state, the hypotenuse of the right triangle of the locking block (711) faces the puncture direction of the puncture needle body (42) extending out of the hollow tube body (1), and its right-angled side forms a surface contact engagement with the side wall of the first locking groove (713).

6. The safety retraction mechanism for a digestive tract puncture needle according to claim 5, characterized in that: The retraction trigger (72) includes a trigger bracket (721). The outer side wall of the hollow tube (1) is provided with a receiving groove (722) extending along its axial direction. The trigger bracket (721) is embedded in the receiving groove (722) and forms an axial sliding fit with the receiving groove (722). The trigger bracket (721) is fixedly installed with a pressing protrusion (723) corresponding to the locking block (711). The contact surface of the pressing protrusion (723) is an inclined surface that fits against the inclined side of the locking block (711). When the trigger bracket (721) is pushed toward the axis of the hollow tube (1), the extrusion protrusion (723) abuts against the inclined side of the locking block (711) through the inclined surface, driving the locking block (711) to disengage from the first locking groove (713) and retract into the locking groove (712), and the pre-tension of the pull spring (64) drives the puncture needle body (42) to retract.

7. The safety retraction mechanism for a digestive tract puncture needle according to claim 6, characterized in that: The retraction trigger (72) also includes a trigger rod (724) fixedly connected to the trigger bracket (721). The trigger rod (724) is symmetrically arranged on both radial sides of the hollow tube (1). The trigger rod (724) and the hollow tube (1) form a sliding fit along its axial direction. The end of the trigger rod (724) is fixedly connected to an anti-slip protrusion (725).

8. The safety retraction mechanism for a digestive tract puncture needle according to claim 7, characterized in that: The hollow tube (1) is fitted with a sealing end cap (8) at the end away from the flexible guide tube (2). The pull-back rod (5) passes through the sealing end cap (8) and forms a sliding sealing connection with the sealing end cap (8). The sealing end cap (8) is equipped with a needle tip protection component (9) for protection after the needle tip retracts.

9. The safety retraction mechanism for a digestive tract puncture needle according to claim 8, characterized in that: The needle tip protection assembly (9) includes a protective sleeve (91) rotatably mounted on the sealing end cap (8), the protective sleeve (91) being fitted over the outside of the hollow tube body (1), and the protective sleeve (91) being made of medical silicone rubber. The inner wall of the protective sleeve (91) is provided with a circumferential locking rib, and the outer circumferential wall of the sealing end cap (8) is provided with a locking groove that matches the locking rib. An elastic shrink ring (92) is fixedly sleeved on the end of the protective sleeve (91) near the flexible guide tube (2). The elastic shrink ring (92) is normally sleeved on the outside of the hollow tube body (1) and is in a pre-stretched state. After rotating the protective sleeve (91) to release the locking rib from the locking groove and unlock it, pull the protective sleeve (91) away from the flexible guide tube (2) to release its support for the elastic shrink ring (92). The elastic shrink ring (92) shrinks quickly through its own elasticity to wrap the port of the flexible guide tube (2) and achieves sealing protection after the needle tip retracts.

Images