Variable curvature puncture needle with adjustable tip bevel

Abstract

The present application relates to the technical field of medical devices, in particular to a variable curvature puncture needle with adjustable needle tip angle, comprising a needle tip, a needle body, a pushing needle, and a connecting mechanism arranged between the needle tip and the needle body; the connecting mechanism comprises a cylindrical shaft matched with the needle tip and a bearing structure arranged on the contact surface of the cylindrical shaft, the needle tip and the needle body; the bearing structure adopts a micro ball bearing, the needle tip is driven to deflect around the cylindrical shaft by the pushing needle, the dynamic adjustment of the angle and the bending of the needle tip are realized, the steering performance and the operation accuracy of the puncture needle are significantly improved, the tissue damage during the operation can be reduced and the complex anatomical path can be adapted, and the puncture needle has high clinical practical value.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a variable curvature puncture needle with an adjustable tip angle. Background Technology

[0002] As an indispensable tool in clinical diagnosis and treatment, the core function of the puncture needle is to achieve precise puncture of target tissues or blood vessels. However, the design of traditional puncture needles has long been limited by fixed bevel angles and non-adjustable curvature, leading to significant challenges in complex anatomical structures or delicate surgeries. Specific problems include: 1. Fixed bevel angles restrict turning flexibility: The bevel angle of traditional puncture needles is commonly fixed at 12°-30°. During the puncture, the operator needs to manually adjust the direction of needle insertion. However, in deep tissues or tortuous blood vessels, such as coronary interventions or percutaneous hepatic biliary drainage, fixed bevel angles are difficult to adapt to dynamic anatomical paths. After the needle tip enters the blood vessel, due to the elastic recoil of the blood vessel wall or obstruction by calcified plaques, it is difficult to correct the direction by adjusting the needle angle, requiring multiple punctures and increasing the risk of blood vessel wall damage and hematoma formation. Under ultrasound or CT image guidance, the fixed bevel angle needle tip, due to insufficient turning ability, cannot match the ideal path displayed on the image in real time. Especially in minimally invasive surgery, the limited operating space further amplifies errors. 2. Uncontrollable curvature of pre-bent needles: Existing pre-bent puncture needles, such as J-type guide needles and controllable bending catheters, can provide a certain curvature, but their bending angle is a preset fixed value, such as 30° or 45°. This type of design has the defects of poor anatomical adaptability and lack of dynamic adjustment during operation. Different patients have significantly different degrees of vascular tortuosity. For example, elderly patients have severely tortuous iliac arteries, and the fixed curvature cannot meet individual needs. If unexpected obstacles such as calcified plaques or anatomical variations are encountered during puncture, the curvature cannot be adjusted in real time to bypass the obstacles, leading to surgical failure or complications. 3) Visual scale dependence and operational complexity: Existing adjustable puncture needles quantify the adjustment range through mechanical scales, but they have limitations such as visual interference, human error, and a steep learning curve. Operators need to frequently visually align the scale, which can distract their attention in image-guided surgery and increase the risk of operational errors. Scale reading is affected by viewing angle and lighting, especially in minimally invasive endoscopic surgery, where instrument obstruction can easily lead to misjudgment. Complex scale systems require long-term training to master, limiting their popularization in emergency or primary healthcare. 4. Limitations of existing improvement technologies: In recent years, some patents have attempted to improve puncture accuracy through auxiliary mechanisms, but the dynamic adjustment problem has not been fundamentally solved: Guidewire drive scheme: Relying on arterial pressure to push the guidewire in, although it reduces manual operation, it cannot actively control the needle tip deflection angle, and the friction between the guidewire and the needle core may lead to difficulty in retraction; Pressure sensor feedback: It indicates the needle tip position by monitoring puncture resistance, but it lacks a dynamic control mechanism for the needle tip posture and cannot achieve active path correction; Electric adjustment device: It uses a motor to drive the needle body to bend, but the structure is complex, the cost is high, and there is a risk of electromagnetic interference, making it difficult to be compatible with imaging equipment such as MRI.

[0003] Therefore, there is an urgent need for a puncture needle that can adjust the tip angle and curvature in real time during surgery to overcome the limitations of traditional instruments, improve puncture accuracy, and reduce surgical risks. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a variable curvature puncture needle with an adjustable needle tip angle.

[0005] An adjustable tip angle variable curvature puncture needle includes a needle tip, a needle body, a pusher needle, and a connecting mechanism disposed between the needle tip and the needle body;

[0006] The connecting mechanism includes a cylindrical shaft that engages with the needle tip deflection and a bearing structure disposed on the contact surfaces of the cylindrical shaft, the needle tip, and the needle body.

[0007] The bearing structure described above uses miniature ball bearings.

[0008] The pusher needle is located inside the needle body, with its distal end in contact with the needle tip and its proximal end connected to an external micro stepper motor.

[0009] One end of the pusher needle is wedge-shaped.

[0010] The needle tip is configured with an arc-shaped groove that matches the wedge-shaped surface.

[0011] The axial displacement d of the push needle is linearly proportional to the needle tip deflection angle θ: θ=k*d, where the transmission coefficient k is determined by the wedge surface inclination angle α and the groove geometric parameters.

[0012] The radius of curvature R formed by the deflection of the needle tip is given by the formula R = L eff / θ is calculated, where L eff The effective length from the tip of the needle to the hinge point.

[0013] The pusher pin is made of a superelastic nickel-titanium alloy with an elastic modulus of 28-41 GPa.

[0014] The needle tip surface is coated with a lubricating coating to reduce frictional resistance, with a friction coefficient ≤0.05.

[0015] The contact surface between the needle body and the push needle is provided with a wear-resistant ceramic coating, and a locking knob is provided on the side wall of the needle body.

[0016] The deflection resistance of the miniature ball bearing is ≤0.1N·mm.

[0017] The beneficial effects of this invention are: by pushing the needle to drive the needle tip to deflect around the cylindrical axis, the invention achieves dynamic adjustment of the oblique angle and formation of the needle tip bending, which significantly improves the turning performance and operation accuracy of the puncture needle, reduces intraoperative tissue damage and adapts to complex anatomical paths, and has high clinical practical value. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Figure 1 This is a schematic diagram of the overall structure of the puncture needle of the present invention;

[0020] Figure 2 This invention provides a diagram illustrating the deflection state of the needle tip driving mechanism.

[0021] Figure 3 This is an enlarged view showing the details of the cylindrical shaft connection of the present invention;

[0022] Reference numerals: 1. Needle tip; 2. Needle body; 3. Push needle; 4. Cylindrical shaft; 5. Locking knob; 6. Lubricating coating; 7. Bearing structure; 8. Arc-shaped groove; 9. Wedge-shaped surface. Detailed Implementation

[0023] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below.

[0024] like Figures 1 to 3 As shown, an adjustable tip angle variable curvature puncture needle includes a needle tip 1, a needle body 2, a pusher needle 3, and a connecting mechanism disposed between the needle tip 1 and the needle body 2.

[0025] The connecting mechanism includes a cylindrical shaft 4 that deflects and engages with the needle tip 1, and a bearing structure 7 disposed on the contact surface of the cylindrical shaft 4, the needle tip 1, and the needle body 2.

[0026] like Figure 1 As shown, the bearing structure 7 adopts a miniature ball bearing. By pushing the needle 3, the needle tip 1 is driven to deflect around the cylindrical shaft 4, realizing dynamic adjustment of the oblique angle and bending of the needle tip 1. This significantly improves the turning performance and operation accuracy of the puncture needle, reduces intraoperative tissue damage, and adapts to complex anatomical paths, thus having high clinical practical value.

[0027] like Figure 1 As shown, the push needle 3 of the present invention is disposed inside the needle body 2, with its distal end in contact with the tail of the needle tip 1 and its proximal end connected to an external micro stepper motor. When the push needle 3 moves axially, the distal end of the push needle 3 abuts against the tail of the needle tip 1, forcing the needle tip 1 to deflect around the cylindrical axis 4, changing the angle of the needle tip 1 and forming a pre-bend.

[0028] Specifically, as one embodiment of the present invention, such as Figure 3 As shown, one end of the push needle 3 is a wedge-shaped surface 9.

[0029] like Figure 3 As shown, the tail of the needle tip 1 is configured as an arc-shaped groove 8 that matches the wedge-shaped surface 9.

[0030] Specifically, the distal end of the push needle 3 is machined into a wedge-shaped surface with a 25° inclination angle, which precisely matches the arc-shaped groove at the tail of the needle tip 1. When the push needle 3 moves axially, the wedge-shaped surface contacts the groove, generating a vertical component force that drives the needle tip 1 to deflect around the cylindrical axis 4. The axial displacement d of the push needle 3 and the deflection angle θ of the needle tip satisfy a linear proportional relationship.

[0031] θ = k*d 0.8 ≤ k ≤ 1.2 rad / mm

[0032] The transmission coefficient k is determined by the wedge inclination angle α and the groove geometry.

[0033] The radius of curvature R formed by the deflection of the needle tip 1 is given by the formula R = L eff / θ is calculated, where L eff The effective length from the tip of the needle to the hinge point.

[0034] Specifically, the pusher needle 3 is made of superelastic nickel-titanium alloy with an elastic modulus of 28-41 GPa, ensuring complete reset after deflection with an error of ≤ ±0.5°. To avoid fatigue fracture, the pusher needle 3 is placed inside the needle body 2.

[0035] Specifically, the surface of the needle tip 1 is coated with a lubricating coating 6 to reduce frictional resistance, with a friction coefficient ≤0.05, thereby reducing tissue puncture resistance. The needle tip 1 is hinged to the needle body 2 via a cylindrical shaft 4, and the needle tip 1 can deflect around the cylindrical shaft 4, which is a pin-type structure.

[0036] The contact surface between the needle body 2 and the push needle 3 is provided with an anti-wear ceramic coating to reduce sliding friction resistance.

[0037] The needle body 2 is provided with a locking knob 5 on its side wall. The locking knob 5 serves as a locking mechanism to fix the position of the push needle in order to maintain the target angle and curvature.

[0038] The deflection resistance of the miniature ball bearing is ≤0.1N·mm.

[0039] like Figure 1As shown, the initial state of the puncture needle is a straight needle with a deflection angle θ = 0° and a radius of curvature R = ∞. The operator rotates the locking knob 5 on the side wall of the needle body 2 to release the fixed state of the push needle 3 and confirms that the needle tip 1 is aligned with the axis of the needle body 2 with an error ≤ ±0.5°. The operator drives the micro stepper motor to move the push needle 3 to the distal end until the wedge-shaped surface at the distal end of the push needle 3, with an inclination angle α = 25°, contacts the arc-shaped groove at the tail of the needle tip 1, generating a vertical component force F⊥ = Fpush * sinα, which drives the needle tip to deflect around the cylindrical axis 4 by θ = k * d, which is actually mechanically limited.

[0040] According to the formula R = Leff / θ, adjust the radius of curvature, rotate the locking knob 5 clockwise, and generate an axial locking force Flock ≥ 5N through the threaded joint to fix the position of the pushing needle 3. The puncture needle is then percutaneously inserted into the tissue artery. Figure 2 As shown, the curved path of the needle tip 1 extends naturally along the blood vessel wall, avoiding branch vessels. The ultrasound image shows that after the needle tip reaches the target position, the locking knob 5 is rotated counterclockwise to release the push needle. The push needle 3, made of nickel-titanium alloy, is reset under the action of superelasticity. θ reset = 0° ± 0.3°. The needle body 2 is withdrawn to complete the needle placement. The needle tip returns to its initial state for needle withdrawal.

[0041] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely prisms of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A variable curvature puncture needle with adjustable tip angle, characterized in that: It includes a needle tip (1), a needle body (2), a pusher needle (3), and a connecting mechanism disposed between the needle tip (1) and the needle body (2); The connecting mechanism includes a cylindrical shaft (4) that deflects and engages with the needle tip (1), and a bearing structure (7) disposed on the contact surface of the cylindrical shaft (4), the needle tip (1), and the needle body (2). The bearing structure (7) described above uses a miniature ball bearing; The push needle (3) is located inside the needle body (2), with its distal end in contact with the tail of the needle tip (1) and its proximal end connected to an external micro stepper motor; one end of the push needle (3) is a wedge-shaped surface (9); the tail of the needle tip (1) is set as an arc-shaped groove (8) that matches the wedge-shaped surface (9).

2. The variable curvature puncture needle with adjustable tip angle according to claim 1, characterized in that: The pusher needle (3) is made of superelastic nickel-titanium alloy with an elastic modulus of 28-41 GPa.

3. The variable curvature puncture needle with adjustable tip angle according to claim 1, characterized in that: The needle tip (1) is coated with a lubricating coating (6) to reduce frictional resistance, with a friction coefficient ≤0.

05.

4. The variable curvature puncture needle with adjustable tip angle according to claim 1, characterized in that: The contact surface between the needle body (2) and the push needle (3) is provided with a wear-resistant ceramic coating, and the side wall of the needle body (2) is provided with a locking knob (5).

5. The variable curvature puncture needle with adjustable tip angle according to claim 1, characterized in that: The deflection resistance of the miniature ball bearing is ≤0.1N·mm.

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