Sternum puncture needle

Abstract

The present application relates to the technical field of medical devices, and discloses a sternal puncture needle, which comprises a needle core, a needle tube body and a handle, the handle being slidably sleeved on the needle tube body. A first locking mechanism and a second locking mechanism are arranged between the needle tube body and the handle, and a firing mechanism is arranged for unlocking the second locking mechanism. The first locking mechanism maintains the spacing between the handle and the needle tube seat when not in use; the second locking mechanism realizes the rigid connection between the handle and the needle tube by the cooperation of a locking ring and a radial locking rod. The firing mechanism comprises a compression spring and a firing plate, and the bottom of the firing plate is provided with an inclined trigger plate. During the puncture process, the doctor releases the first locking mechanism when the needle tip reaches the bone surface; when the needle tip enters the bone marrow cavity and the resistance suddenly decreases, the firing spring releases the stored energy to push the needle tube body forward, the inclined surface of the trigger plate forces the radial locking rod to exit the locking ring, the second locking is released, and the handle is separated from the needle tube. Thereafter, the handle can be pushed along the needle tube while the needle tube is stationary, thereby completely preventing overshoot damage.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically relating to a sternal puncture needle. Background Technology

[0002] Sternal bone marrow aspiration is a routine invasive procedure for obtaining bone marrow fluid for the diagnosis of hematological diseases, tumor metastases, and infectious diseases. Clinically, a sternal aspiration needle is typically used to puncture the bone marrow cavity through the midline of the sternum. A typical sternal aspiration needle includes a tube, a core, and a handle. The tip of the tube is sharp, the core is inserted inside the tube to prevent tissue blockage, and the handle is fixedly connected to the tube or allows for depth pre-adjustment via a threaded structure.

[0003] Currently, to prevent damage to the mediastinum, major blood vessels, or heart behind the sternum from excessively deep punctures, existing techniques mainly employ the following two methods:

[0004] Depth-adjustable limit: The maximum extension length of the needle tip is preset by setting a threaded adjusting nut or a movable baffle between the handle and the needle tube. During operation, the doctor estimates the puncture depth based on the patient's body shape, sternal thickness, and subcutaneous soft tissue thickness, and adjusts the limiting device. When the needle tube advances to the preset depth, the limiting mechanism abuts against the handle or needle tube seat to prevent further insertion.

[0005] Reliance on manual control: This method relies entirely on the doctor's perception of sudden changes in resistance during the puncture process. When the needle tip breaks through the bone cortex and enters the medullary cavity, the doctor quickly stops advancing based on experience.

[0006] However, the aforementioned existing technologies still have certain technical limitations: when using depth-adjustable limiting, although a theoretical maximum depth can be set, in actual puncture, due to significant individual differences in sternal thickness, cortical bone hardness, and subcutaneous fat layer thickness among different patients, even with preoperative estimation via imaging or palpation, it is difficult to guarantee an accurate match between the preset depth and the actual anatomical depth. Obese patients have thicker subcutaneous tissue, resulting in large variations in the distance from the skin to the bone surface, with measurement errors reaching several millimeters; while osteoporotic patients have thinner cortical sternums, making the breakthrough sensation less pronounced. When resistance suddenly decreases, the doctor often continues to apply force due to inertia, causing the needle to potentially rush forward even after passing the limiting barrier, resulting in over-rush injury. Therefore, simply relying on a preset depth cannot fundamentally solve the over-rush problem at the moment of breakthrough.

[0007] In view of this, the inventor conducted in-depth research on the aforementioned deficiencies in the prior art, which led to the creation of this case. Summary of the Invention

[0008] The purpose of this invention is to provide a sternal puncture needle that automatically unlocks and allows the handle to be pushed freely when entering the medullary cavity by mechanically sensing changes in puncture resistance, thereby fundamentally preventing over-injection damage and improving the safety of puncture.

[0009] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0010] A sternal puncture needle includes a needle core, a needle tube body, and a handle. The needle core has a core seat at its top, and the needle tube body has a needle tube seat at its top. The core seat and the needle tube seat are threadedly connected. The handle is slidably sleeved on the needle tube body. A first locking mechanism and a second locking mechanism are provided between the needle tube body and the handle. The needle tube body also has a firing mechanism for unlocking the second locking mechanism. The first locking mechanism is located at the top of the handle, maintaining a distance between the top of the handle and the bottom of the needle tube seat. The handle has a cavity inside to accommodate the second locking mechanism and the firing mechanism. A mounting ring is fixed on the inner wall of the cavity, and the mounting ring is coaxially arranged with the needle tube body. The second locking mechanism includes a locking ring slidably sleeved on the needle tube body and a plurality of rings arranged in a circumferential array. A locking rod is slidably mounted on the mounting ring. The inner wall of the mounting ring has multiple mounting holes for mounting the locking rod, which are radially arranged. The circumferential surface of the locking ring has multiple radially arranged locking holes. The top of the mounting ring has multiple through slots communicating with the mounting holes. A contact rod is formed on the locking rod, passing through the through slots. The firing mechanism includes a firing spring sleeved on the needle tube body and a firing plate fixedly sleeved on the needle tube body. One end of the firing spring is fixedly connected to the inner top wall of the cavity, and the other end is fixedly connected to the top of the firing plate. The bottom of the firing plate is also provided with multiple trigger plates, the bottom of which has a driving inclined surface that cooperates with the contact rod. A limiting plate is also fixedly sleeved on the needle tube body, located at the bottom of the locking ring.

[0011] Furthermore, the first locking mechanism includes a rotating ring rotatably sleeved on the top of the handle and a plurality of limiting posts arranged in a circumferential annular array on the top of the rotating ring; a plurality of bearing plates are formed on the circumferential surface of the needle holder, each of which abuts against the plurality of limiting posts. By rotating the rotating ring, the limiting posts and the bearing plates can be misaligned, thereby releasing the needle holder. The operation is simple and reliable, and it can be effectively locked during transportation.

[0012] Furthermore, multiple anti-slip grooves are formed on the circumferential surface of the rotating ring; the top of the limiting post is hemispherical. The anti-slip grooves facilitate the doctor's rotation operation, and the hemispherical limiting post has less friction when in contact with the support plate, resulting in smoother rotation and release.

[0013] Furthermore, multiple limiting sliders are formed on the circumferential surface of the firing plate, and limiting grooves that cooperate with the limiting sliders are formed on the inner wall of the cavity. The cooperation between the limiting sliders and the limiting grooves ensures that the firing plate does not rotate circumferentially during axial movement, so that the trigger plate and the contact rod are always accurately aligned.

[0014] Furthermore, the second locking mechanism also includes a stop spring, one end of which is fixedly connected to the wall of the mounting hole, and the other end is fixedly connected to the end of the locking rod. After being fired, the stop spring pushes the locking rod to return to its original position inward, so that the circumferential surface of the locking rod contacts the bottom of the limiting plate, thereby enabling the handle to drive the needle tube body backward when the needle is withdrawn; at the same time, its elastic coefficient is much smaller than that of the firing spring, so it does not affect the firing and unlocking process.

[0015] Furthermore, a tapered surface is formed on the upper part of the circumferential surface of the limiting plate. The tapered surface can guide the locking rod after reset to slide smoothly to the bottom of the limiting plate, avoiding jamming and improving the reliability of needle retraction.

[0016] Furthermore, a guide wheel is rotatably mounted on the top of the contact rod, and the guide wheel makes rolling contact with the drive ramp. This rolling friction reduces wear and resistance, making the unlocking action more sensitive.

[0017] Furthermore, a buffer mechanism is installed at the bottom of the handle. The buffer mechanism includes a buffer plate coaxially arranged with the handle and a buffer spring connected between the buffer plate and the handle. The buffer plate has a through hole through which the needle body passes. When the second lock is unlocked, the buffer spring is compressed when the handle is pushed in the air, buffering the handle and preventing overshoot due to inertia, thus improving operating comfort and safety.

[0018] With the above structure, the sternal puncture needle of this invention, compared with the prior art, uses a first locking mechanism to lock when not in use, keeping the top of the handle and the bottom of the needle tube seat at a preparatory stroke. When in use, the first locking mechanism is released, allowing the needle tube body to move forward by that stroke. The firing spring is in a compressed, energy-stored state, and the locking rod is inserted into the locking hole to achieve a second lock, rigidly connecting the handle and the needle tube. When the resistance drops sharply as the needle tip enters the medullary cavity, the firing spring releases, pushing the needle tube body forward. The driving ramp of the trigger plate presses down on the contact rod, driving the locking rod radially outward from the locking hole, releasing the second lock. Afterward, the handle disengages from the needle tube, allowing the handle to be pushed freely along the needle tube while the needle tube remains stationary, thus completely preventing overshoot and significantly improving the safety of sternal puncture. Attached Figure Description

[0019] The present invention can be further illustrated by the non-limiting embodiments given in the accompanying drawings;

[0020] Figure 1 This is a schematic diagram of the structure of the present invention;

[0021] Figure 2 for Figure 1 A cross-sectional schematic diagram;

[0022] Figure 3 for Figure 1A schematic diagram of the decomposition process;

[0023] Figure 4 This is a schematic diagram of the structure of the needle body in this invention;

[0024] Figure 5 This is a schematic diagram of the structure of the first locking mechanism in this invention;

[0025] Figure 6 for Figure 2 A magnified schematic diagram of the partial structure at point A in the middle;

[0026] Figure 7 for Figure 3 A magnified schematic diagram of the local structure at point B;

[0027] Figure 8 for Figure 4 A magnified schematic diagram of the structure at point C.

[0028] The symbols of the main components are explained as follows: needle core 1, core seat 11, needle tube body 2, needle tube seat 21, bearing plate 211, limiting plate 22, conical surface 221, handle 3, cavity 31, limiting slide groove 312, mounting ring 311, mounting hole 3111, through groove 3112, first locking mechanism 4, rotating ring 41, anti-slip texture 411, limiting post 42, second locking mechanism 5, locking ring 51, locking hole 511, locking rod 52, contact rod 521, guide wheel 522, push spring 53, firing mechanism 6, firing spring 61, firing plate 62, limiting slider 622, trigger plate 621, driving inclined surface 6211, buffer mechanism 7, buffer plate 71, through hole 711, buffer spring 72. Detailed Implementation

[0029] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that similar or identical parts are referred to by the same reference numerals in the drawings or description. Implementations not shown or described in the drawings are forms known to those skilled in the art. In addition, directional terms mentioned in the embodiments, such as "up," "down," "top," "bottom," "left," "right," "front," and "back," are only for reference to the directions in the drawings and are not intended to limit the scope of protection of the present invention.

[0030] like Figures 1 to 8As shown, a sternal puncture needle includes a needle core 1, a needle body 2, and a handle 3. The needle core 1 is a solid stainless steel rod with a core seat 11 fixed to its top (the end closest to the operator). The outer surface of the core seat 11 has anti-slip textures for easy gripping and rotation. The needle body 2 is a thin-walled stainless steel tube with its front end (the end furthest from the operator) ground into a sharp puncture tip for penetrating tissue. A needle tube seat 21 is fixed to the top (rear end) of the needle body 2. The outer diameter of the needle tube seat 21 is larger than that of the needle body 2, and it has a threaded hole inside. The lower part of the core seat 11 has external threads, forming a fine-pitch thread connection with the internal threads of the needle tube seat 21. This threaded connection reliably secures the needle core during puncture, preventing it from dislodging. Furthermore, when sampling is required, the doctor can easily rotate the core seat to remove the needle core.

[0031] The handle 3 is an injection-molded part made of medical-grade plastic (such as ABS or polyoxymethylene), and its overall shape is roughly cylindrical. The outer surface has anti-slip textures for easy gripping. The handle 3 is slidably fitted onto the outside of the syringe body 2, meaning the syringe body 2 can slide axially relative to the handle 3. A cavity 31 is formed inside the handle 3 to accommodate the various mechanisms described later. A first locking mechanism 4 is provided at the top of the handle 3 (near the syringe holder). Specifically, the first locking mechanism 4 includes a rotating ring 41 and six limiting posts 42. The rotating ring 41 is rotatably fitted onto the outer circumferential surface of the top of the handle 3, and its outer circumferential surface has multiple anti-slip textures 411 to increase friction. The six limiting posts 42 are evenly distributed circumferentially and fixed to the top surface of the rotating ring 41, with the top of each limiting post 42 machined into a hemispherical shape. Six support plates 211 are correspondingly fixed to the circumferential surface of the syringe holder 21. The support plates 211 extend radially outward, and their lower surfaces are flat. In the unused state (e.g., during product manufacturing, transportation, sterilization, and pre-use preparation), the rotating ring 41 is rotated to a position where the limiting post 42 is vertically aligned with the support plate 211, and the top hemispherical surface of the limiting post 42 abuts against the lower surface of the support plate 211. This abutting contact maintains a fixed axial distance D between the top of the handle 3 and the bottom of the needle holder 21; in this embodiment, D is 2 mm. This distance is the preparatory stroke required for the subsequent firing mechanism operation.

[0032] A mounting ring 311 is fixedly installed on the inner wall of the cavity 31 of the handle 3, and the mounting ring 311 is coaxially arranged with the needle body 2. Four radial mounting holes 3111 are evenly distributed along the circumference of the mounting ring 311, each hole penetrating the inner and outer walls of the mounting ring 311 radially. A locking rod 52 is slidably installed in each mounting hole 3111. The locking rod 52 is cylindrical, and its outer diameter forms a clearance fit with the inner diameter of the mounting hole 3111, allowing the locking rod 52 to slide freely radially within the mounting hole 3111. A stop spring 53 is provided between the tail (radial outer end) of each locking rod 52 and the hole wall of the mounting hole 3111. This stop spring 53 is a compression spring, one end of which is fixed to the hole wall of the mounting hole 3111, and the other end is fixed to the end of the locking rod 52, always applying an inward radial thrust (i.e., towards the axis of the needle body) to the locking rod 52. In this embodiment, the spring constant of the stop spring 53 is much smaller than that of the spring constant of the firing spring 61, which will be described later.

[0033] The top of the mounting ring 311 (on the side near the needle holder) has a through groove 3112 corresponding to each mounting hole 3111. The through groove 3112 communicates with the mounting hole 3111 and extends axially. Each locking rod 52 has a contact rod 521 fixed on it. The contact rod 521 extends upward (i.e., toward the needle holder) through the corresponding through groove 3112 and can move radially within the through groove 3112. A guide wheel 522 is rotatably mounted on the top of the contact rod 521 via a pin. The guide wheel 522 can rotate freely around the pin.

[0034] The second locking mechanism 5 also includes a locking ring 51, which is slidably sleeved on the needle body 2. Four radial locking holes 511 are formed on the outer circumference of the locking ring 51. The positions of the locking holes 511 correspond one-to-one with the positions of the locking rods 52, and the inner diameter of the locking holes 511 forms a clearance fit with the outer diameter of the inner end of the locking rods 52. In the initial state, the inner end of the locking rods 52 is inserted into the locking holes 511 under the thrust of the abutment spring 53, thereby achieving radial locking between the locking ring 51 and the mounting ring 311, thus forming a rigid connection between the handle 3 and the needle body 2 (because the locking ring 51 is fixed to the mounting ring 311 via the locking rod 52, and the mounting ring 311 is fixed to the handle 3; the locking ring 51 also engages with the locking rod 52 through the locking holes 511; simultaneously, the locking ring 51 is slidably sleeved on the needle body 2, but its axial relative movement is restricted by the locking rod 52). A limiting plate 22 is also fixedly fitted onto the needle body 2, located at the bottom of the locking ring 51 (i.e., the side closest to the needle tip). Initially, the top of the limiting plate 22 abuts against the bottom of the locking ring 51, thus limiting the locking ring 51 downwards and preventing it from sliding down. The upper circumferential surface of the limiting plate 22 is machined into a tapered surface 221, with its outer diameter gradually increasing from top to bottom. The function of this tapered surface will be demonstrated during the subsequent needle retraction process.

[0035] The firing mechanism 6 includes a firing spring 61 and a firing plate 62. The firing spring 61 is a cylindrical helical compression spring, sleeved on the needle body 2. One end (upper end) is fixedly connected to the inner top wall of the cavity 31 (i.e., the inner surface of the top of the handle 3), and the other end (lower end) is fixedly connected to the top of the firing plate 62. The firing plate 62 is also sleeved on the needle body 2 and fixedly connected to the needle body 2 (e.g., by a tight fit or screw fixation), so the firing plate 62 can move axially with the needle body 2. Four limiting sliders 622 are symmetrically arranged on the circumferential surface of the firing plate 62, and correspondingly, axially extending limiting grooves 312 are provided on the inner wall of the cavity 31. The limiting sliders 622 slide within the limiting grooves 312. This fit structure ensures that the firing plate 62 can only move axially and cannot rotate relative to the handle 3, thereby ensuring accurate alignment of the subsequent trigger plate and guide wheel.

[0036] Four trigger plates 621 extend downwards from the bottom of the firing plate 62 (the side closest to the needle tip). The number of trigger plates 621 is the same as the number of locking levers 52 (four in this embodiment), and each trigger plate 621 corresponds to a contact lever 521. Each trigger plate 621 has a drive ramp 6211 machined at its bottom end, with an inclination angle of, for example, 45°. The drive ramp 6211 maintains rolling contact with the guide wheel 522 at the top of the corresponding contact lever 521. That is, the guide wheel 522 abuts against the drive ramp 6211. When the firing plate 62 moves up and down, the drive ramp 6211 pushes the guide wheel 522, causing the guide wheel 522 to roll along the ramp, thereby driving the contact lever 521 and the locking lever 52 to move radially.

[0037] A buffer mechanism 7 is also installed at the bottom of the handle 3 (near the needle tip). The buffer mechanism 7 includes a buffer plate 71 and a buffer spring 72. The buffer plate 71 is annular, with a through hole 711 in its center for the needle body 2 to pass through. The buffer plate 71 is coaxially mounted with the handle 3 and can slide freely on the needle body 2. The buffer spring 72 is a compression spring, sleeved on the needle body 2, with one end fixed to the buffer plate 71 and the other end fixed to the bottom end face of the handle 3. The buffer spring 72 always applies a downward pushing force to the buffer plate 71, so that the buffer plate 71 maintains a certain distance from the bottom of the handle 3 when there is no external force.

[0038] Initial assembly and transportation status: At the time of shipment, the first locking mechanism 4 is in the locked position, that is, the limiting post 42 on the rotating ring 41 is vertically aligned and in contact with the bearing plate 211 on the needle holder 21. At this time, the axial distance between the top of the handle 3 and the bottom of the needle holder 21 is D=2mm. The firing spring 61 is compressed. Under the action of the abutment spring 53, the inner end of the locking rod 52 is inserted into the locking hole 511 of the locking ring 51, and the second locking mechanism is in the locked state. The handle 3 and the needle body 2 are rigidly connected through the locking rod 52, and the two cannot move axially relative to each other. The entire puncture needle structure is compact and stable, and can withstand vibration and external force during transportation and sterilization.

[0039] The method of using this invention is as follows: The doctor takes the puncture needle out of the packaging, first aligns the needle tip with the puncture point, and then applies a pushing force to perform the puncture. During this stage, the needle tip penetrates the skin and subcutaneous tissue sequentially. Due to the low resistance of these soft tissues, the doctor applies a relatively small pushing force. At this time, the first locking mechanism 4 remains locked, and the contact between the limiting post 42 and the support plate 211 restricts the possibility of the needle body 2 moving forward relative to the handle 3. Therefore, the needle body 2 and the handle 3 move forward together as a whole. The second locking mechanism 5 remains locked, ensuring the rigidity of the transmission. This stage of operation is exactly the same as with conventional puncture needles, and the doctor does not need to perform any additional operations.

[0040] When the needle tip reaches the periosteum and contacts the cortical bone of the sternum, the puncture resistance increases significantly (typically reaching 10-20N). At this point, the doctor can clearly feel the sudden change in sensation. According to the design of this invention, the doctor needs to actively rotate the rotating ring 41 at this moment. Specifically, the doctor pinches the outer circumference of the rotating ring 41 with his thumb and forefinger, applying rotational force with the help of the anti-slip texture 411, causing the rotating ring 41 to rotate relative to the handle 3 at a certain angle (e.g., 90° or 180°). After rotation, the limiting post 42 is offset from the support plate 211 in the circumferential direction, the limiting post 42 no longer abuts against the support plate 211, and the first locking mechanism 4 is released. After release, the needle body 2 has the possibility of moving forward a preparatory stroke D (2mm), but because the second locking mechanism 5 is still locked (the locking rod 52 is still inserted into the locking hole 511), and the needle tip is subjected to greater cortical bone resistance, the needle body 2 will not move forward immediately. At this time, the firing spring 61 is still in a compressed and stored state, and the needle body 2 remains stationary relative to the handle 3.

[0041] The doctor continues to apply force, and the needle tip begins to penetrate the hard cortical bone. It should be noted that the spring force of the firing spring 61 should be selected so that, under normal cortical bone resistance, the needle body 2 will not rush forward prematurely, but can release rapidly after the resistance disappears. This embodiment achieves this requirement through a reasonable spring stiffness design. The moment the needle tip breaks through the cortical bone and instantly enters the medullary cavity, the axial resistance drops sharply from 15-20N to almost zero (the pressure inside the medullary cavity is extremely low). At this time, the spring force of the firing spring 61 (still around 15N) is much greater than the resistance of the needle tip, and the firing spring 61 quickly releases its stored energy, pushing the firing plate 62 and the needle body 2 fixedly connected to it forward (towards the puncture direction). The distance moved is approximately the preparatory stroke D (2mm). During the forward movement of the needle body 2, the firing plate 62 moves forward along with it, and the trigger plate 621 fixed at its bottom also moves forward synchronously. The driving ramp 6211 at the bottom of the trigger plate 621 moves relative to the guide wheel 522 at the top of the contact rod 521. As the driving ramp 6211 moves forward and downward, it generates an outward radial force on the guide wheel 522, forcing the guide wheel 522 to drive the contact rod 521 and the locking rod 52 to slide radially outward. When the locking rod 52 slides outward, its inner end completely exits the locking hole 511 of the locking ring 51. During the outward sliding of the locking rod 52, the abutment spring 53 is further compressed. At this point, the second locking mechanism 5 is completely unlocked.

[0042] After the second locking mechanism is unlocked, there is no longer any rigid connection between the handle 3 and the needle body 2. At this point, the doctor may still push the handle 3 forward due to inertia or not having enough time to stop the thrust. Because the locking lever 52 is no longer in place, the handle 3 will slide forward along the outer wall of the needle body 2 (i.e., push without resistance), while the needle body 2, due to its almost zero resistance at the front end and its small mass, remains essentially stationary under the influence of friction and air resistance, and will not continue to penetrate deeper into the bone marrow cavity. Therefore, even if the doctor continues to apply force, the needle will not advance further, thus completely eliminating over-thrust injury from a mechanical perspective. Simultaneously, as the handle 3 slides forward, its bottom buffer mechanism 7 begins to work: the buffer plate 71 first contacts the patient's skin, the buffer spring 72 is compressed, absorbing the kinetic energy of the handle and cushioning it, preventing the handle from directly impacting the patient's skin and causing discomfort or injury. The doctor will clearly feel the handle "soften" and have a short period of free travel, thus realizing that the bone marrow cavity has been reached and the push can be stopped.

[0043] After the doctor stops advancing the needle, he removes the needle core 1 (rotating the core seat 11 to separate it from the needle holder 21, and then pulling the needle core upwards), and then connects the syringe to the needle holder 21 to aspirate bone marrow fluid. After sampling, the puncture needle needs to be withdrawn from the patient's body. At this time, the doctor pulls the handle 3 backwards (i.e., away from the patient). Since the second locking mechanism has been unlocked, there is no rigid connection between the handle 3 and the needle body 2, and simply pulling the handle 3 will not directly drive the needle body 2 backwards. However, in this embodiment, the needle withdrawal linkage is achieved through the abutment spring 53 and the conical surface 221 of the limiting plate 22. Specifically, after the second locking mechanism is unlocked, the locking rod 52 returns to its original position radially inwards under the action of the abutment spring 53. Since the locking ring 51 has moved forward 2mm with the forward movement of the needle body 2, the inner end of the locking rod 52 no longer aligns with the locking hole 511 after returning to its original position, but instead rests against the conical surface 221 of the limiting plate 22. The guiding effect of the conical surface 221 allows the inner end of the locking rod 52 to slide smoothly to the bottom plane of the limiting plate 22. At this time, the circumferential surface of the locking rod 52 contacts the bottom plane of the limiting plate 22. When the doctor pulls the handle 3 backward, the mounting ring 311 fixed on the handle 3 and the locking rod 52 retract accordingly. The circumferential surface of the locking rod 52 hooks onto the bottom plane of the limiting plate 22, thereby driving the limiting plate 22 and the needle body 2 fixedly connected to it to retract together, finally completely withdrawing the puncture needle from the patient's body. This process requires no additional operation from the doctor and maintains a needle withdrawal feel similar to that of a traditional puncture needle.

[0044] The foregoing has provided a detailed description of a sternal puncture needle provided by the present invention. The specific embodiments described are merely for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A sternal puncture needle, comprising a needle core (1), a needle tube body (2), and a handle (3), wherein the top of the needle core (1) has a core seat (11), and the top of the needle tube body (2) has a needle tube seat (21), the core seat (11) and the needle tube seat (21) being threadedly connected, characterized in that: The handle (3) is slidably sleeved on the needle body (2); a first locking mechanism (4) and a second locking mechanism (5) are provided between the needle body (2) and the handle (3); the needle body (2) is also provided with a firing mechanism (6) for unlocking the second locking mechanism (5); the first locking mechanism (4) is located at the top of the handle (3), so that the top of the handle (3) is spaced from the bottom of the needle seat (21), and the interior of the handle (3) has a space to accommodate the second locking mechanism (5). The cavity (31) of the firing mechanism (6) and the cavity (31) of the firing mechanism (6); a mounting ring (311) is fixed on the inner wall of the cavity (31), and the mounting ring (311) is coaxially arranged with the needle body (2); the second locking mechanism (5) includes a locking ring (51) slidably sleeved on the needle body (2) and a plurality of locking rods (52) arranged in a circumferential annular array and slidably mounted on the mounting ring (311), and a plurality of mounting holes (31) for mounting the locking rods (52) are formed on the inner wall of the mounting ring (311). 11), the mounting hole (3111) is arranged radially, and a plurality of radially arranged locking holes (511) are formed on the circumferential surface of the locking ring (51). A plurality of through grooves (3112) communicating with the mounting hole (3111) are formed on the top of the mounting ring (3111). A contact rod (521) passing through the through groove (3112) is formed on the locking rod (52). The firing mechanism (6) includes a firing spring (61) sleeved on the needle body (2) and a fixedly sleeved on the needle body. (2) The firing plate (62) is fixedly connected at one end to the inner top wall of the cavity (31), and at the other end to the top of the firing plate (62); the bottom of the firing plate (62) is also provided with multiple trigger plates (621), and the bottom of the trigger plate (621) has a driving inclined surface (6211) that cooperates with the contact rod (521); a limiting plate (22) is also fixedly sleeved on the needle body (2), and the limiting plate (22) is located at the bottom of the locking ring (51).

2. The sternal puncture needle according to claim 1, characterized in that: The first locking mechanism (4) includes a rotating ring (41) rotatably sleeved on the top of the handle (3) and a plurality of limiting posts (42) arranged in a circumferential annular array on the top of the rotating ring (41); a plurality of bearing plates (211) are formed on the circumferential surface of the needle tube seat (21) and respectively abut against the plurality of the limiting posts (42).

3. The sternal puncture needle according to claim 2, characterized in that: The rotating ring (41) has multiple anti-slip grooves (411) formed on its circumferential surface; the top of the limiting post (42) is hemispherical.

4. The sternal puncture needle according to claim 1, characterized in that: Multiple limiting sliders (622) are formed on the circumferential surface of the firing plate (62), and a limiting groove (312) that cooperates with the limiting sliders (622) is formed on the inner wall of the cavity (31).

5. A sternal puncture needle according to claim 1, characterized in that: The second locking mechanism (5) also includes a stop spring (53), one end of which is fixedly connected to the wall of the mounting hole (3111), and the other end is fixedly connected to the end of the locking rod (52).

6. The sternal puncture needle according to claim 1, characterized in that: A conical surface (221) is formed on the upper part of the circumferential surface of the limiting plate (22).

7. A sternal puncture needle according to claim 1, characterized in that: A guide wheel (522) is rotatably mounted on the top of the contact rod (521), and the guide wheel (522) makes rolling contact with the driving inclined surface (6211).

8. A sternal puncture needle according to claim 1, characterized in that: The bottom of the handle (3) is also equipped with a buffer mechanism (7), which includes a buffer plate (71) coaxially arranged with the handle (3) and a buffer spring (72) connected between the buffer plate (71) and the handle (3); the buffer plate (71) has a through hole (711) through which the needle body (2) passes.

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