A stable micro-tweezer for sciatic nerve microinjection in mice

Abstract

The present application belongs to the technical field of experimental animal surgery and micro-injection auxiliary instrument, and specifically discloses a stable micro-support for mouse sciatic nerve micro-injection, which comprises a handle, an extension rod and a working head, the handle is fixedly connected with the extension rod, the extension rod is fixedly connected with the working head, the working head is integrally formed by a horizontal section and an upward section, a nerve stabilizing groove for clamping the mouse sciatic nerve is arranged at the included angle between the horizontal section and the upward section, and the nerve stabilizing groove is upwardly open. The extension rod is formed by sleeving an outer tube and an inner tube, the outer tube is provided with a positioning hole, the inner tube is provided with a spring sheet and a positioning button, and the extension rod is realized with step locking. In use, the horizontal section is slid under the nerve, the instrument is lifted, the nerve is dropped into the nerve stabilizing groove along the upward section and clamped stably in the transverse direction, and then the micro-injection can be performed. The present application can pad up and clamp stably the soft sciatic nerve with a diameter of about 1 mm, and significantly improves the accuracy, stability and repeatability of mouse sciatic nerve micro-injection.

Description

Technical Field

[0001] This invention belongs to the field of experimental animal surgery and microinjection auxiliary device technology, specifically relating to a stable micro-support for micro-injection into the sciatic nerve of mice. Background Technology

[0002] In oncology, neuroscience, and drug development, the mouse sciatic nerve tumor model is an important experimental animal model, widely used in research on tumor invasion mechanisms, screening of drugs for neurogenic tumors, and evaluation of targeted therapies. One of the key steps in constructing this model is the precise injection of a very small volume (approximately 1 µL) of tumor cell suspension into the sciatic nerve of a live mouse.

[0003] However, this procedure faces numerous technical challenges. First, the mouse sciatic nerve is only about 1 mm in diameter, soft, and has a smooth, moist surface, making it extremely prone to sliding and shifting during respiration or manipulation within the surgical field. Second, the sciatic nerve is surrounded by loose connective tissue, lacking a rigid support structure, making it difficult to fix it in a specific position and height during manual manipulation. Third, in existing experimental procedures, researchers typically use ordinary forceps or nerve hooks to temporarily fix the nerve by clamping, but clamping itself can easily cause damage to the perineurium, axonal compression, or even nerve fiber rupture; or the nerve can be directly placed on the surface of surrounding tissue for injection, in which case the nerve, lacking effective support, will shift upon contact with the needle tip, leading to a series of problems such as needle deviation, needle tip puncture of the nerve perineurium, and leakage of the suspension into surrounding tissues, severely affecting the success rate and reproducibility of model construction.

[0004] Several auxiliary devices for animal experiments already exist in the prior art. For example, Chinese patent CN202123282224.0 discloses a sciatic nerve injector for experimental animals, which improves injection accuracy by using a right-angle bent needle and a rotating component to achieve parallel needle insertion along the nerve's course. However, this patent mainly focuses on optimizing the structure of the needle itself and does not address how to effectively fix and support the sciatic nerve, a soft and easily slippery target tissue. Another example is Chinese patent CN202321756240, which discloses a fixation device for sciatic nerve ligation in mice. This device uses a base, suction cup, support rod, clamping plate, and straps to fix the mouse as a whole for sciatic nerve ligation. However, this device fixes the entire mouse, not the sciatic nerve itself, making its structure complex and unsuitable for the local nerve stability requirements of micro-injection scenarios.

[0005] To address the limitations of existing technologies in providing a dedicated structure that can both elevate the nerve from surrounding tissues and stabilize it laterally while maintaining a constant working surface direction, as well as the lack of a rod structure that allows for rapid and repeatable length adjustment at different surgical field depths, improvements are needed to the structure of the stable micro-support used for micro-injection of the sciatic nerve in mice, thereby resolving the current technical problems. Summary of the Invention

[0006] The purpose of this invention is to provide a stable micro-support for micro-injection of the sciatic nerve in mice, which can support and laterally stabilize the soft sciatic nerve with a diameter of about 1 mm, preventing the nerve from sliding or shifting during injection, thus significantly improving the accuracy, stability and repeatability of micro-injection of the sciatic nerve in mice.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a stabilizing micro-support for micro-injection of the sciatic nerve in mice, comprising: a handle, a telescopic rod fixedly connected to the handle, a working head fixedly connected to the telescopic rod away from the handle, the working head being integrally formed of a horizontal section and an upwardly inclined section, the upwardly inclined section being fixedly connected to the telescopic rod; a nerve stabilizing groove for securing the sciatic nerve of a mouse is provided at the angle between the horizontal section and the upwardly inclined section, the extension direction of the nerve stabilizing groove being perpendicular to the extension direction of the horizontal section and the upwardly inclined section, and the opening facing upward.

[0008] To better realize the present invention, the telescopic rod is formed by connecting an outer tube and an inner tube. The tail end of the outer tube is fixedly connected to the handle, the inner tube is axially slidably fitted inside the outer tube, and the working head is fixedly connected to the front end of the inner tube.

[0009] To better realize the present invention, the cross-section of the inner tube is a non-circular cross-section, and the inner hole of the outer tube is a non-circular guide hole that matches the cross-section of the inner tube, so that the inner tube can only slide along the axial direction and cannot rotate around the axis.

[0010] To better realize the present invention, the outer tube has a plurality of positioning holes along the axial direction in its tube wall, the inner tube is equipped with a spring plate, the inner tube has a positioning button that can move radially in its tube wall, and the free end of the spring plate abuts against the bottom of the positioning button.

[0011] To better realize the present invention, there are 6 positioning holes, and the spacing between adjacent positioning holes is 10mm, which corresponds to the extension length of the telescopic rod to form six positions: 30mm, 40mm, 50mm, 60mm, 70mm and 80mm.

[0012] To better realize the present invention, the upward tilt angle of the upward tilting segment relative to the horizontal segment is 10° to 30°.

[0013] To better realize the present invention, the cross-section of the nerve stabilizing groove is arc-shaped, U-shaped, V-shaped or swallowtail-shaped.

[0014] To better realize the present invention, the radius of the neural stabilizing groove is 0.5 to 0.7 mm.

[0015] To better realize the present invention, the working head has a width of 3-4 mm and a thickness of 0.8-1.2 mm.

[0016] Beneficial effects: Compared with the prior art, the present invention has the following beneficial effects: First, significant nerve stability. The nerve stabilizing groove of this invention can elevate and laterally stabilize the sciatic nerve from the surrounding tissue, preventing the nerve from slipping or shifting during injection. This greatly improves the accuracy of 1µL micro-injection, significantly reduces extravasation of the suspension, and markedly lowers the incidence of nerve injury. Comparative experiments have verified that using the micro-support of this invention increases the success rate of needle insertion on the first attempt from approximately 10% with existing methods (hand-operated or with ordinary forceps / hooks) to approximately 95%, reduces the extravasation rate from approximately 90% to approximately 10%, reduces the incidence of nerve injury from approximately 50% to approximately 5%, and shortens the average operation time from approximately 10 minutes to approximately 3 minutes.

[0017] Second, the orientation is constant and the operation is consistent. The inner tube of this invention adopts a non-circular cross-section (preferably D-shaped) to cooperate with the corresponding non-circular guide hole of the outer tube, so that the inner tube can only slide along the axis and cannot rotate around the axis, thereby ensuring that the nerve stabilizing groove on the working head that carries the nerve is always facing upward. This design ensures that the starting state of each operation is consistent, eliminates the operation error caused by the deviation of the nerve stabilizing groove orientation due to the rotation of the working head, and greatly improves the repeatability of the experiment.

[0018] Third, the length is adjustable and the repeatability is good. This invention adopts a stepped positioning mechanism that combines a spring button with a positioning hole. The extension length of the telescopic rod can be set in six steps of 10mm within the range of 30mm to 80mm (30mm, 40mm, 50mm, 60mm, 70mm, 80mm). Each adjustment can accurately return to the same length, resulting in good experimental repeatability and suitability for mice of different sizes and different surgical field depths.

[0019] Fourth, it is easy to operate and can be completed with one hand. The push-pull extension and button locking operations of this invention do not require rotation throughout the entire process, and the operator can complete the length adjustment with one hand; the locking method is mechanical locking, which does not slip or loosen, and the length is stable and reliable during use.

[0020] Fifth, it is easy to clean and sterilize. The working head part of this invention that comes into contact with nerves can be made of medical-grade plastic or medical-grade stainless steel (such as 316L), with a smooth, burr-free surface that can withstand high-temperature and high-pressure sterilization, meeting the aseptic operation requirements for animal experiments. Attached Figure Description

[0021] Figure 1 This is the overall front view of the invention (the telescopic rod is in the extended state); Figure 2 This is a front view of the working head of the present invention; Figure 3 This is a top view of the working head of the present invention; Figure 4 This is a cross-sectional view of the telescopic rod structure of the present invention (comparison of locked and unlocked states). Figure 5 This is a schematic diagram of the telescopic range of the present invention.

[0022] In the diagram: 1. Handle; 2. Outer tube; 3. Inner tube; 4. Spring plate; 41. Positioning button; 5. Working head; 6. Upward tilting section; 7. Horizontal section; 8. Nerve stabilizing groove; 9. Sciatic nerve; 10. Positioning hole. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example like Figure 1 - Figure 5 As shown, a stable micro-support for micro-injection of the sciatic nerve in mice includes a handle 1, a telescopic rod, and a working head 5.

[0025] The handle 1 is located at the rear of the instrument and is for the operator to grip. The outer edge of the handle 1 has anti-slip textures (such as knurling) to increase grip friction and prevent the instrument from slipping from the hand during operation. The handle 1 can be disc-shaped, cylindrical, or other ergonomic shapes. In this embodiment, the handle 1 adopts a disc-shaped design with a diameter of approximately 30–44 mm.

[0026] The length of the telescopic rod is adjustable to accommodate differences in surgical field depth under varying experimental conditions. In this embodiment, the telescopic rod is formed by connecting an outer tube 2 and an inner tube 3. The tail end (rear end) of the outer tube 2 is fixedly connected to the handle 1, and the front end of the outer tube 2 is open. The inner tube 3 is axially slidably fitted inside the outer tube 2, with its front end extending beyond the front opening of the outer tube 2 and fixedly connected to the working head 5. The rear end of the inner tube 3 is located inside the outer tube 2 and will not come out.

[0027] Anti-rotation design of telescopic poles: In this embodiment, the inner tube 3 has a non-circular cross-section, and the inner hole of the outer tube 2 is a non-circular guide hole that matches the non-circular cross-section. This design allows the inner tube 3 to slide only along the axial direction of the outer tube 2, and prevents it from rotating around the axis.

[0028] Specifically, the cross-section of the inner tube 3 can be D-shaped (i.e., a plane is cut into a circular cross-section), and correspondingly, the inner hole of the outer tube 2 is also D-shaped. D-shaped fitting is a simple and effective anti-rotation method, with low processing cost and high fitting accuracy. In addition, the cross-section of the inner tube 3 can also be square, rectangular, elliptical, semi-circular, polygonal, or any non-circular fitting form that can restrict relative rotation, such as a key / keyway on a circular cross-section. Any non-circular cross-section where the inner tube 3 and outer tube 2 are mutually fitted can achieve the above-mentioned anti-rotation function.

[0029] The significance of the anti-rotation function is that when the operator pushes or pulls the telescopic rod to adjust the length, the inner tube 3 will not rotate relative to the outer tube 2, and therefore the direction of the working head 5 fixed to the front end of the inner tube 3 will not change. Since the opening direction of the nerve stabilizing groove 8 is fixed to the direction of the working head 5, the anti-rotation structure ensures that the opening direction of the nerve stabilizing groove 8 always faces upwards and will not deflect during length adjustment or use. This ensures that the orientation of the nerve stabilizing groove 8 is consistent during each operation, eliminating operational errors caused by changes in the orientation of the nerve stabilizing groove 8.

[0030] The telescopic pole features a segmented locking design: In this embodiment, the telescopic rod uses an elastic button that engages with the positioning hole 10 to achieve segmented locking.

[0031] The outer tube 2 has several positioning holes 10 axially formed in its wall. Each positioning hole 10 penetrates the wall of the outer tube 2, and its diameter matches the diameter of the positioning button 41. In this embodiment, there are six positioning holes 10, with a spacing of 10mm between adjacent holes, corresponding to six extension lengths of the telescopic rod: 30mm, 40mm, 50mm, 60mm, 70mm, and 80mm. The diameter of each positioning hole 10 is approximately 2mm.

[0032] The inner tube 3 contains a spring plate 4 (e.g., a leaf spring). One end of the spring plate 4 is fixed to the inside of the inner tube 3 (e.g., by riveting or welding), and the free end (movable end) of the spring plate 4 abuts against the bottom of the positioning button 41. The positioning button 41 is located on the wall of the inner tube 3 and can move radially along the inner tube 3. The head of the positioning button 41 extends out of the outer wall of the inner tube 3, and its head is dome-shaped for easy pressing with a finger.

[0033] When the inner tube 3 slides relative to the outer tube 2 to a certain position, such that the positioning button 41 is aligned with a positioning hole 10 on the outer tube 2, the elastic force of the spring plate 4 drives the positioning button 41 to extend radially outward, pass through the wall of the inner tube 3, and enter the positioning hole 10. The shoulder of the positioning button 41 abuts against the wall of the positioning hole 10, thereby locking the inner tube 3 axially and preventing it from sliding further.

[0034] When adjusting the length of the telescopic rod, the operator presses the head of the positioning button 41 with their finger, overcoming the elastic force of the spring plate 4, causing the positioning button 41 to retract radially inward below the inner wall of the outer tube 2 (i.e., the positioning button 41 is completely out of the positioning hole 10). At this time, the axial constraint of the inner tube 3 is released, and the operator can push and pull the inner tube 3 to slide it relative to the outer tube 2 to the desired position. After reaching the target position, the positioning button 41 is released, and the elastic force of the spring plate 4 automatically pushes the positioning button 41 into the corresponding positioning hole 10, achieving relocking. The entire adjustment process does not require rotation and can be completed with one hand.

[0035] The telescopic rod (outer tube 2 and inner tube 3), handle 1, spring plate 4, positioning button 41, and other components need to have certain structural strength and wear resistance, and can be made of medical-grade stainless steel (such as 316L stainless steel). 316L stainless steel has good corrosion resistance and can withstand high-temperature and high-pressure sterilization (121°C, 15psi, 20 minutes), meeting the aseptic operation requirements for animal experiments. The spring plate 4 can be made of spring steel (such as 65Mn), which has good elasticity and fatigue life.

[0036] The working head 5 is fixed to the front end of the inner tube 3 (i.e., the front end of the inner tube 3). Since the working head 5 is in direct contact with the nerve, it needs to have good biocompatibility and a smooth surface to avoid mechanical damage to the sciatic nerve 9. The working head 5 can be manufactured in one piece using medical-grade plastics (such as polyetheretherketone (PEEK), polycarbonate (PC), etc.) through injection molding, which is cost-effective and easy to mold into complex nerve-stabilizing groove 8 shapes. The surface of the working head 5 in contact with the nerve should be polished to ensure a smooth, burr-free surface. The working head 5 can be fixed by bonding, threaded connection, or interference fit.

[0037] In this embodiment, the front working end of the working head 5 is integrally formed from a horizontal section 7 and an upwardly inclined section 6. The horizontal section 7 is approximately 7 mm long, 3.5 mm wide, and 1 mm thick. The lower surface of the horizontal section 7 is flat, allowing it to slide smoothly onto the tissue surface below the sciatic nerve 9 during operation. The upper surface of the horizontal section 7 is a smooth plane, preventing frictional damage to the sciatic nerve 9.

[0038] The upward-sloping section 6 is located after the horizontal section 7 (i.e., the end closest to the handle 1), and extends upward from the rear end of the horizontal section 7. The rear end (upper end) of the upward-sloping section 6 is fixedly connected to the front end of the inner tube 3. The length of the upward-sloping section 6 is about 5 mm, the width is the same as that of the horizontal section 7 (about 3.5 mm), and the thickness is the same as that of the horizontal section 7 (about 1 mm).

[0039] The angle between the horizontal segment 7 and the upward-sloping segment 6 (upward-sloping angle α) is 10° to 30°, preferably about 15°. The selection of the upward-sloping angle α is based on the following considerations: if the upward-sloping angle is too small (close to 0°), the working head 5 will be almost horizontal, requiring the entire micro-support to be lowered below the sciatic nerve 9 during operation, which is inconvenient for the operator to observe and operate; if the upward-sloping angle is too large, the tangential force on the sciatic nerve 9 when it slides into the nerve stabilization groove 8 along the upward-sloping segment 6 will increase, which may cause unnecessary traction on the nerve. Experiments have verified that an upward-sloping angle range of 10° to 30° can achieve a good balance between operational convenience and nerve safety, with about 15° being the optimal value.

[0040] A nerve stabilizing groove 8 is provided at the angle between the horizontal segment 7 and the upward-sloping segment 6. This nerve stabilizing groove 8 is a transverse nerve stabilizing groove 8, meaning that the length direction (extension direction) of the nerve stabilizing groove 8 is perpendicular to the extension direction of the horizontal segment 7 and the upward-sloping segment 6 (i.e., perpendicular to the main axis direction of the instrument), extending through the entire width of the working head 5, with the opening of the nerve stabilizing groove 8 facing upward. The cross-section of the nerve stabilizing groove 8 is arc-shaped (semi-circular or U-shaped), with a radius of approximately 0.5–0.7 mm, preferably approximately 0.6 mm, matching the outer diameter (approximately 1 mm) of the mouse sciatic nerve 9. When the sciatic nerve 9 is placed in this nerve stabilizing groove 8, the nerve stabilizing groove 8 can laterally stabilize the nerve, preventing it from sliding to the sides.

[0041] The cross-section of the nerve stabilizing groove 8 can also be U-shaped, V-shaped, or dovetail-shaped, among other shapes. The U-shaped nerve stabilizing groove 8 has an arc-shaped bottom and vertical or slightly inclined sidewalls, providing a larger contact area and better holding stability. The V-shaped nerve stabilizing groove 8 is suitable for cases with large variations in nerve diameter and can adapt to nerves of different diameters. The dovetail-shaped nerve stabilizing groove 8 has inwardly tapering sidewalls, more reliably preventing the nerve from dislodging from the nerve stabilizing groove 8. All of the above shapes are optional embodiments of the present invention.

[0042] Measurements showed that the outer diameter of the exposed segment of the sciatic nerve 9 in experimental mice (BALB / c nude mice, 6-8 weeks old, weighing approximately 22g, n=10) was 0.50±0.05mm (mean±standard deviation, range 0.45-0.55mm). The radius R of the nerve stabilizing groove 8 is preferably slightly larger than the nerve radius, ensuring a single-sided fitting gap of approximately 0.1mm (i.e., R≈nerve radius + single-sided gap). This guarantees that the nerve stabilizing groove 8 can both accommodate the nerve and provide lateral restraint without causing compression damage. Therefore, a radius R of 0.6mm for the nerve stabilizing groove 8 is considered ideal. Of course, depending on the diameter of the sciatic nerve 9 in different mouse strains, the radius of the nerve stabilizing groove 8 can be adjusted within the range of 0.5-0.7mm.

[0043] The working principle of this invention can be summarized as follows: Step 1: Instrument Preparation and Length Adjustment. Based on the depth of the surgical field, the operator presses the positioning button 41 to retract it below the inner wall of the outer tube 2, while simultaneously pushing and pulling the inner tube 3 to slide relative to the outer tube 2 to the appropriate extension length. Once the target position is reached, the positioning button 41 is released, and the elastic force of the spring plate 4 automatically pushes the positioning button 41 into the corresponding positioning hole 10, achieving locking. Because the cross-section of the inner tube 3 is non-circular (preferably D-shaped), and it cooperates with the corresponding non-circular guide hole of the outer tube 2, the inner tube 3 will not rotate during sliding. Therefore, the opening direction of the nerve stabilizing groove 8 on the working head 5 always remains upward.

[0044] Step 2: Expose the sciatic nerve 9. Under a stereomicroscope, after anesthetizing and disinfecting the experimental mice (e.g., BALB / c nude mice, 6-8 weeks old), make a skin incision along the posterolateral aspect of the thigh, bluntly dissect the muscles and fascia, and expose a segment of the sciatic nerve 9 (approximately 5-10 mm). Gently retract the connective tissue around the nerve with fine microforceps (e.g., pointed toothless forceps), and gently pull the nerve upwards with fine forceps to leave a gap below the nerve for insertion of the working head 5 at the horizontal level 7.

[0045] Step 3: Insert the working head 5. Keep the opening of the nerve-stabilizing groove 8 of the working head 5 facing upwards (the direction is constant due to the anti-rotation structure). Slowly slide the horizontal segment 7 along the long axis of the sciatic nerve 9 into the exposed area directly below the nerve at a near-zero angle of attack (i.e., the lower surface of the horizontal segment 7 is parallel to the tissue surface below the nerve). Avoid directly pushing against the nerve body during insertion; the movement should be gentle and at a constant speed.

[0046] Step 4: Elevate and secure the nerve. Gently lift end 1 of the instrument handle to move the working head 5 upward. The sciatic nerve 9 naturally slides along the inclined surface of the superior segment 6 into the nerve stabilizing groove 8 located at the angle between the horizontal segment 7 and the superior segment 6. The arc-shaped surface of the nerve stabilizing groove 8 fits tightly against the outer wall of the nerve, laterally securing the nerve and simultaneously elevating it from the surrounding tissue by a certain height (approximately the thickness of the working head 5, i.e., about 1 mm), creating a clear needle insertion space and field of vision for subsequent injection operations.

[0047] Step 5: Microinjection. Stabilize the instrument and draw up approximately 1 µL of tumor cell suspension using a microinjector (such as a Hamilton syringe or glass microneedle). Insert the needle vertically or at a small angle (approximately 10°–20°) above the nerve stabilization groove 8 into the trapped sciatic nerve 9 (insertion depth controlled within the space between the epineurium and perineurium). Inject the suspension slowly (approximately 0.1–0.5 µL / second), pause for approximately 5–10 seconds after injection, and then slowly withdraw the needle to minimize backflow of the suspension.

[0048] Step Six: Instrument Removal. After injection, slowly lower the instrument handle 1, and gently pull the nerve up with fine forceps to dislodge it from the nerve stabilization groove 8. Then, slowly withdraw the horizontal segment 7 along the original path. The entire withdrawal process should be performed under direct microscopic observation to ensure that the edge of the nerve stabilization groove 8 does not scrape the nerve and to avoid secondary damage to the nerve.

[0049] Precautions: Throughout the procedure, the surgical field should be kept moist with saline solution to prevent nerve dryness; all movements should be gentle and at a constant speed; the surface of the nerve stabilization groove 8 in contact with the nerve should be smooth and free of burrs; if the insertion is not complete on the first attempt, the instrument should be completely withdrawn and reinserted to avoid repeated blind probing under the nerve.

[0050] Comparative experiment Experimental materials: The experimental animals were BALB / c nude mice, 6-8 weeks old, weighing about 22g, a total of 20 mice, which were randomly divided into a control group (10 mice) and an experimental group (10 mice).

[0051] The control group was operated using existing techniques, either manually or with forceps / hooks. After exposing the sciatic nerve 9, the tissues surrounding the nerve were held with forceps to provide temporary fixation, and then a microsyringe was used for injection.

[0052] Experimental group operation method: The stable micro-tender of the present invention was used and operated according to the method described in Example 6.

[0053] Evaluation indicators: The differences between the two groups were statistically analyzed in the following four indicators: (1) First-time needle insertion success rate (i.e., the ratio of successful insertion of the needle tip into the space between the nerve epineurium and perineurium on the first insertion without leakage of the suspension); (2) Suspension leakage rate (the ratio of visible fluid leakage from the nerve surface after injection); (3) Nerve injury rate (the ratio of axonal breakage, epineurium tear, etc., visible under a microscope after the nerve is taken for HE staining); (4) Average operation time (the total time from nerve exposure to completion of injection and removal of the instrument).

[0054] Experimental results:

[0055] Experimental conclusions: The above experimental data fully demonstrate that, compared with the prior art, the present invention can increase the success rate of needle insertion from 10% to 95%, reduce the leakage rate of suspension from 90% to 10%, reduce the incidence of nerve injury from 50% to 5%, and shorten the average operation time from about 10 minutes to about 3 minutes. All indicators have been significantly improved.

[0056] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A stable micro-support for micro-injection into the sciatic nerve of mice, characterized in that, include: Handle (1), the handle (1) is fixedly connected to a telescopic rod, the telescopic rod is fixedly connected to a working head (5) away from the handle (1), the working head (5) is integrally formed of a horizontal section (7) and an upward tilting section (6), the upward tilting section (6) is fixedly connected to the telescopic rod; a nerve stabilizing groove (8) for stabilizing the sciatic nerve (9) of a mouse is provided at the angle between the horizontal section (7) and the upward tilting section (6), the extension direction of the nerve stabilizing groove (8) is perpendicular to the extension direction of the horizontal section (7) and the upward tilting section (6), and the opening faces upward.

2. The stabilizing micro-support for micro-injection into the sciatic nerve of mice according to claim 1, characterized in that, The telescopic rod is formed by connecting an outer tube (2) and an inner tube (3). The tail end of the outer tube (2) is fixedly connected to the handle (1). The inner tube (3) is axially slidably fitted inside the outer tube (2). The working head (5) is fixedly connected to the front end of the inner tube (3).

3. A stable micro-support for micro-injection into the sciatic nerve of mice according to claim 2, characterized in that, The inner tube (3) has a non-circular cross section, and the inner hole of the outer tube (2) is a non-circular guide hole that matches the cross section of the inner tube (3), so that the inner tube (3) can only slide along the axial direction and cannot rotate around the axis.

4. A stable micro-support for micro-injection into the sciatic nerve of mice according to claim 2, characterized in that, The outer tube (2) has a plurality of positioning holes (10) along the axial direction on its wall. The inner tube (3) is equipped with a spring plate (4). The inner tube (3) has a positioning button (41) that can move radially on its wall. The free end of the spring plate (4) abuts against the bottom of the positioning button (41).

5. A stabilizing micro-support for micro-injection into the sciatic nerve of mice according to claim 4, characterized in that, The number of positioning holes (10) is 6, and the distance between adjacent positioning holes (10) is 10mm, forming six positions of 30mm, 40mm, 50mm, 60mm, 70mm and 80mm corresponding to the extension length of the telescopic rod.

6. A stable micro-support for micro-injection into the sciatic nerve of mice according to claim 1, characterized in that, The upward tilt angle of the upward tilting segment (6) relative to the horizontal segment (7) is 10° to 30°.

7. A stable micro-support for micro-injection into the sciatic nerve of mice according to claim 1, characterized in that, The cross-section of the neural stabilizing groove (8) is arc-shaped, U-shaped, V-shaped or swallowtail-shaped.

8. A stable micro-support for micro-injection into the sciatic nerve of mice according to claim 1, characterized in that, The radius of the neural stabilizing groove (8) is 0.5 to 0.7 mm.

9. A stabilizing micro-support for micro-injection into the sciatic nerve of mice according to claim 1, characterized in that, The working head (5) has a width of 3-4 mm and a thickness of 0.8-1.2 mm.

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