Puncture navigation tool for pedicle of vertebra with automatic deviation correction and breakage prevention

Abstract

The present application relates to the technical field of medical devices, and discloses a pedicle puncture navigation tool with automatic deviation correction and breakage prevention, which comprises an operating handle, a puncture rod and a puncture head arranged at the distal end of the puncture rod; the puncture head comprises, from the distal end to the proximal end, a triangular pyramid puncture end, a sliding guide section and a micro neck section which are connected in sequence and smoothly transitioned. The triangular pyramid puncture end is used for initial cutting into the bone, and the cutting edges stop at the bottom surface connected with the sliding guide section; the outer surface of the sliding guide section is an ellipsoidal smooth convex curved surface, and no cutting edges or cutting edges are arranged; the micro neck section is located at the proximal end of the maximum outer diameter part of the sliding guide section. After the triangular pyramid puncture end completes the initial cutting, the blunt surface bears the bone wall reaction force, and under the cooperation of the proximal end avoidance space formed by the micro neck section, the relative sliding along the bone wall is generated, and the passive guiding trend of moving away from the contact side is generated, so that the risk of continuously cutting into the cortical bone wall is reduced, and the outer diameter change of the micro neck can provide auxiliary resistance change information.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and more specifically, to a pedicle puncture navigation tool with automatic deviation correction and anti-wall rupture function. Background Technology

[0002] In posterior spinal surgery (such as pedicle screw fixation), establishing a safe, open path within the bony canal of the pedicle is a crucial foundation for the surgical procedure. The pedicle is a narrow bony canal consisting of hard outer cortical bone and inner cancellous bone, and it is adjacent to the spinal cord, nerve roots, and major blood vessels. Deviation in the puncture trajectory can increase the risk of complications. Currently, some oblique-cut puncture needles used clinically suffer from asymmetrical force distribution; a sharper puncture tip may continue to cut even after contacting the cortical bone wall on one side. Therefore, there is still room for improvement in how to preserve the initial cutting ability of the puncture tip while ensuring that the smooth, blunt surface at the proximal end of the cutting structure absorbs the reaction force from the bone wall upon contact on one side, reducing the tendency for the puncture tip to continue cutting into the bone wall, and providing the operator with information on changes in auxiliary resistance through changes in the proximal outer diameter.

[0003] Chinese patent CN209863975U discloses a pedicle puncture needle, which includes a puncture cannula, a puncture needle core, and a puncture probe, with an elliptical puncture head at the tip of the puncture probe that matches the inner diameter of the puncture cannula. This design focuses on using the elliptical puncture head to reduce the risk of damage to the four walls of the pedicle by the puncture probe.

[0004] Chinese patent CN221712133U discloses a pedicle puncture device that uses an inertial sensor to monitor the puncture posture and display the data to assist the operator in controlling the puncture direction. However, this solution mainly provides auxiliary information from the perspective of external posture monitoring, and its needle body still uses a conical tip, which may increase the operational risk if the puncture trajectory deviates.

[0005] Therefore, there is still room for improvement in how to retain the initial cutting capability while forming a smooth guide surface without cutting edges at the proximal end of the cutting structure with the piercing head, and how to reduce the constraint of the adjacent rod segment on the guiding motion and provide information on the change of auxiliary resistance through the change of the outer diameter of the proximal end of the guide surface. Summary of the Invention

[0006] To at least partially solve the above problems, the present invention provides a pedicle puncture navigation tool with automatic deviation correction and anti-wall rupture function, including an operating handle and a puncture rod connected to the operating handle, wherein a puncture head is provided at the distal end of the puncture rod; The puncture head, from distal to proximal, includes, in sequence, an axially adjacent and smoothly transitioning triangular pyramidal puncture end, a sliding guide section, and a micro-neck section; The bottom surface of the triangular pyramid puncture end is connected to the distal end of the sliding guide section. The triangular pyramid puncture end includes three cutting bevels of equal area that are circumferentially spaced around the central axis of the puncture head. The three cutting bevels intersect to form a puncture tip located on the central axis. Two adjacent cutting bevels intersect to form a cutting edge. The proximal end of each cutting edge terminates at the bottom surface. The outer surface of the sliding guide section is a smooth convex ellipsoidal surface that is rotationally symmetrical about the central axis of the puncture head, and the outer surface is a blunt round guide surface without cutting edges; the maximum outer diameter of the sliding guide section is equal to the diameter of the circumcircle of the bottom surface, and it tapers smoothly near the end of its maximum outer diameter portion. The miniaturized neck segment is located at the proximal end of the maximum outer diameter portion of the sliding guide segment. The minimum outer diameter of the miniaturized neck segment is smaller than the maximum outer diameter of the sliding guide segment. The proximal end of the miniaturized neck segment is smoothly connected to the puncture rod.

[0007] Preferably, the axial height of the puncture end of the triangular pyramid is 0.6 to 0.9 times the diameter of its circumscribed circle; and the axial height of the puncture end of the triangular pyramid is 1.8 mm to 2.2 mm; adjacent cutting bevels are connected by a smooth transition fillet, and the radius of the transition fillet gradually increases from the puncture tip towards the proximal end.

[0008] Preferably, the axial length of the sliding guide section is 3.0 mm to 5.0 mm.

[0009] Preferably, the minimum outer diameter of the miniaturized neck segment is 0.2 mm to 0.3 mm smaller than the maximum outer diameter of the sliding guide segment; the junction of the miniaturized neck segment and its distal sliding guide segment is smoothly connected by a transition fillet.

[0010] Preferably, the miniaturized neck segment gradually thickens from the distal end to the proximal end to form a first gradually expanding segment, the proximal outer diameter of the first gradually expanding segment is equal to the maximum outer diameter of the sliding guide segment, and the axial length of the first gradually expanding segment is 25mm to 30mm; the proximal end of the first gradually expanding segment continues to thicken smoothly through a gradually expanding connecting segment and connects to the main rod of the puncture rod, the outer diameter of the main rod being 7mm to 8mm.

[0011] Preferably, the puncture head and the puncture rod are integrally formed parts made of medical-grade metal material; except for the three cutting bevels at the triangular pyramidal puncture end, the remaining outer surfaces of the puncture head are polished, and the surface roughness Ra is not greater than 0.2μm.

[0012] Preferably, the operating handle is further integrated with an angle measurement navigation component, which is used to indicate the tilt state of the puncture tool relative to the direction of gravity, or to monitor the attitude change of the puncture tool relative to the initial attitude reference.

[0013] Preferably, the angle measurement navigation component is a purely mechanical level, which is embedded in the tail end face of the operating handle. The purely mechanical level includes a universal circular level or a biaxial bubble level.

[0014] Preferably, the angle measurement navigation component is an electronic digital display component, which includes a power module, a microcontroller, and a six-axis inertial measurement sensor encapsulated inside the operating handle, and a display screen disposed on the outer surface of the operating handle; the power module is electrically connected to and supplies power to the microcontroller, the six-axis inertial measurement sensor, and the display screen respectively, and the six-axis inertial measurement sensor and the display screen are electrically connected to the microcontroller respectively.

[0015] Preferably, the operating handle is further provided with a calibration button electrically connected to the microcontroller; the microcontroller is used to set the current attitude data of the six-axis inertial measurement sensor as the initial attitude reference when the calibration button is triggered, and to receive the attitude data collected by the six-axis inertial measurement sensor during the puncture process, to obtain the attitude change information of the puncture tool according to the change of the attitude data relative to the initial attitude reference, and to drive the display screen to display the attitude change information.

[0016] Compared with existing technologies, this invention provides a pedicle puncture navigation tool with automatic deviation correction and anti-wall rupture function, which has at least the following beneficial effects: The three equally spaced cutting bevels at the puncture tip of the triangular pyramid ensure that the axial thrust is applied more evenly to the puncture tip. This reduces the possibility of lateral displacement due to asymmetrical force on a single-sided oblique cut structure and provides cutting guidance for initial bone entry. The proximal ends of each cutting edge terminate at the bottom surface of the triangular pyramid puncture tip and do not extend further to the sliding guide section, concentrating the cutting action at the distal end of the puncture head and providing a clear structural boundary for the proximal ellipsoidal surface without cutting edges to continue into the bone tunnel.

[0017] The sliding guide segment employs a smooth, convex ellipsoidal surface formed by rotating a continuous elliptical arc around its central axis, with no cutting edges or ridges on its outer surface. After the initial cutting is completed by the triangular pyramidal puncture tip, the sliding guide segment enters the bone tunnel with the puncture head. When the needle trajectory deviates, its smooth, blunt surface forms lateral contact with the cortical bone wall, making it less likely to form a continuous cutting fulcrum. The normal reaction force generated by the bone wall on the sliding guide segment, combined with the propulsive force applied by the operator, helps the puncture head to form a passive guiding tendency to slide relative to the bone wall and move away from the contact side of the bone wall, thereby reducing the risk of continuous cutting towards the cortical bone wall. This effect does not mean that the puncture head can automatically return to the geometric center of the pedicle under any deviation and force conditions.

[0018] The miniaturized neck segment is located proximal to the maximum outer diameter of the sliding guide segment and connects to it via a transition fillet, creating a reduced-diameter avoidance area after the maximum outer diameter. When the sliding guide segment makes lateral contact with the wall, this reduced-diameter area helps reduce the restriction on lateral micro-movement and angular adjustment of the distal guide area caused by adjacent segments simultaneously contacting the wall. When the main contact area between the tool and the bone transitions from the maximum outer diameter of the sliding guide segment to the reduced-diameter area corresponding to the miniaturized neck segment, the contact area and friction state may change, resulting in a corresponding change in the axial resistance transmitted through the puncture rod. This change in resistance can serve as auxiliary information for the operator to judge the advancement status, but it is not the sole basis for determining the puncture depth or safe position.

[0019] The triangular pyramidal puncture end, the sliding guide section, and the miniature neck section are axially adjacent and smoothly transitioned, forming a continuous mechanical action relationship of distal cutting, cutting edge termination, ellipsoidal blunt rounded contact wall guidance, and proximal constraint release. The triangular pyramidal puncture end is used for initial entry, and the gradually increasing transition radius gradually weakens the cutting action of the edge near the sliding guide section. Subsequently, the ellipsoidal sliding guide section without a cutting edge provides smooth support and force guidance when the object touches the wall on the side, while the miniature neck section retains a certain amount of motion margin for this guiding process and can provide auxiliary resistance change information. Thus, without setting up an active steering actuator, it is beneficial to improve the operational controllability during the puncture process. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of a pedicle puncture navigation tool with automatic deviation correction and anti-wall-breaking function according to the present invention; Figure 2 For the present invention Figure 1 A magnified schematic diagram of the local structure at point A; Figure 3 This is a schematic diagram of the pedicle puncture navigation tool of the present invention within the pedicle channel.

[0021] In the figure: 1. Operating handle; 2. Puncture rod; 3. Puncture head; 31. Triangular pyramid puncture end; 32. Sliding guide section; 33. Minimally shrunk neck section. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, so that those skilled in the art can implement it based on the description. In this section, "distal end" refers to the end closer to the patient's surgical site and farther from the operator, i.e., the direction of puncture penetration; "proximal end" refers to the end closer to the operator and farther from the patient's surgical site. "Automatic correction" as used herein means that after the triangular cone puncture tip completes the initial cutting, without the need for an active drive or active steering mechanism, when the puncture head deviates and contacts the bone wall, the contact reaction between the ellipsoidal sliding guide segment without cutting edge and the bone wall, as well as the proximal avoidance space formed by the miniaturized neck segment, causes the puncture head to passively slide relative to the bone wall and move away from the contact side of the bone wall. This does not mean that the tool can automatically return to the geometric center of the pedicle under any deviation and force conditions, nor does it mean that it can prevent bone wall perforation under any working condition. The actual needle insertion direction is still controlled by the operator in conjunction with resistance changes, navigation information, and intraoperative imaging.

[0023] like Figures 1-3 As shown, the present invention provides a pedicle puncture navigation tool with automatic deviation correction and anti-wall rupture function, including an operating handle 1, a puncture rod 2, and a puncture head 3. The proximal end of the puncture rod 2 is connected to the front end of the operating handle 1, and the distal end of the puncture rod 2 is provided with the puncture head 3.

[0024] The puncture head 3, from distal to proximal, comprises a triangular pyramidal puncture end 31, a sliding guide section 32, and a miniaturized neck section 33, which are axially adjacent and smoothly connected. The triangular pyramidal puncture end 31 has a bottom surface that connects to the distal end of the sliding guide section 32, and includes three equally spaced cutting bevels of equal area distributed circumferentially around the central axis; adjacent cutting bevels intersect to form cutting edges, and the proximal ends of each cutting edge terminate at the bottom surface. The outer surface of the sliding guide section 32 is a smooth ellipsoidal convex surface formed by rotating a continuous elliptical arc around the central axis. Its outer surface has no cutting edges or cutting ridges, and its maximum outer diameter is equal to the circumcircle diameter of the bottom surface of the triangular pyramidal puncture end 31, tapering smoothly proximal to the maximum outer diameter. The miniaturized neck section 33 is located proximal to the maximum outer diameter of the sliding guide section 32, and its minimum outer diameter is smaller than the maximum outer diameter of the sliding guide section 32, smoothly transitioning proximally to the puncture rod 2. Thus, the puncture head 3 forms a continuous transition along the axial direction from the distal cutting profile to the proximal ellipsoidal blunt guide profile, and a diameter reduction avoidance area is formed at the proximal end of the guide section.

[0025] Example 1: In this example, the puncture head 3 and the puncture rod 2 are integrally formed from medical-grade metal material. Specifically, the medical-grade metal material can be medical-grade stainless steel, medical-grade titanium alloy, or medical-grade cobalt-chromium alloy.

[0026] The bottom surface of the triangular pyramid puncture end 31 smoothly contacts the distal end of the sliding guide section 32. The axial height of the triangular pyramid puncture end 31 is 0.8 times the diameter of its circumscribed circle. In this embodiment, the diameter of the circumscribed circle is 2.5 mm, thus determining the axial height of the triangular pyramid puncture end 31 to be 2.0 mm.

[0027] The outer surface of the sliding guide section 32 is an ellipsoidal smooth convex surface formed by rotating a continuous elliptical arc around the central axis of the puncture head 3. Its cross-section perpendicular to the central axis is circular, and its axial cross-section profile is a continuous smooth elliptical arc. The outer surface of the sliding guide section 32 is not provided with cutting edges or cutting ridges, and it tapers smoothly near the proximal end of the maximum outer diameter portion. In this embodiment, the circumcircle diameter of the bottom surface of the triangular pyramidal puncture end 31 is 2.5 mm, the maximum outer diameter of the sliding guide section 32 is 2.5 mm, and the axial length is 4.0 mm. The miniaturized neck segment 33 is located proximal to rear of the sliding guide segment 32. Its minimum outer diameter is 0.2 mm to 0.3 mm smaller than the maximum outer diameter of the sliding guide segment 32; in this embodiment, it is 0.2 mm, meaning the diameter at its narrowest point is 2.3 mm (to illustrate the miniaturized neck structure, see attached...). Figure 1-3 The diameter difference between the miniaturized neck segment 33 and the sliding guide segment 32 is appropriately increased. The junction of the miniaturized neck segment 33 and its distal sliding guide segment 32 is connected by a smooth transition concave fillet to form a diameter reduction transition zone from 2.5 mm to 2.3 mm, while reducing the possibility of snagging tissue during needle withdrawal. The miniaturized neck segment 33 is located proximal to the maximum outer diameter of the sliding guide segment 32, so that a diameter reduction avoidance space is formed after the maximum outer diameter, thereby reducing the limitation on the lateral micro-movement and angle adjustment of the distal guide area when the puncture head touches the wall on the side and the adjacent rod segment is also attached to the wall.

[0028] The miniaturized neck segment 33 gradually thickens proximally through a smooth curved surface to form a first gradually expanding segment. This first gradually expanding segment extends until its outer diameter returns to 2.5 mm, and its axial length is 28 mm. The proximal end of the first gradually expanding segment continues to expand its outer diameter through a gradually expanding connecting segment and smoothly connects to the main rod of the puncture rod 2. The outer diameter of the main rod is 7.5 mm. The main rod constitutes an external load-bearing rod segment near the operating handle 1, used to receive and transmit the axial thrust and torque applied by the operator, and is located outside the pedicle bony passage during normal use.

[0029] Except for the three cutting bevels of the triangular pyramid puncture end 31, which remain mechanically ground, the outer surfaces of the sliding guide section 32, the miniaturized neck section 33, and the puncture rod 2 are all electrolytically polished. The operating handle 1 is made of medical polymer material, and its tail end face is fixed with a purely mechanical level as an angle-measuring navigation component using medical-grade adhesive. The purely mechanical level is a universal circular level or a biaxial bubble level.

[0030] The working principle and beneficial effects of the above technical solution are as follows: During the clinical procedure, the operator holds the operating handle 1 and places the puncture head 3 at the predetermined thoracic pedicle bone entry point. In the initial puncture stage, because the three cutting bevels have equal areas and are evenly distributed around the central axis, the axial thrust applied by the operator can be applied to the three cutting bevels relatively evenly, allowing the puncture tip to cut into the bone in the predetermined direction. This helps to reduce the possibility of lateral deviation due to asymmetrical force on the cutting surfaces.

[0031] After the puncture head 3 enters the bony passage of the pedicle, the triangular cone puncture end 31 has completed its initial cutting, and the sliding guide segment 32 located proximal to it subsequently enters the bone passage. If the needle trajectory deviates and contacts the cortical bone wall, the ellipsoidal blunt surface of the sliding guide segment 32 forms lateral contact with the bone wall. Since this surface does not have cutting edges or ridges and is polished, it is not easy to form a continuous cutting fulcrum when it contacts the bone wall. At this time, the cortical bone wall generates a normal reaction force on the sliding guide segment 32; if the operator continues to apply the advancing force and the distal guide area has a certain lateral micro-movement and angle adjustment margin, this reaction force helps the puncture head 3 to form a passive guiding tendency to slide relative to the bone wall and move away from the contact side bone wall, thereby reducing the tendency to continue cutting into the cortical bone wall on that side.

[0032] As the puncture head 3 continues to advance, when the main contact area between the tool and the bone transitions from the maximum outer diameter of the sliding guide section 32 to the reduced diameter of the corresponding narrowed neck section 33, the contact area and friction state between the tool's periphery and the bone may change, causing a corresponding change in the axial needle insertion resistance transmitted to the hand via the puncture rod 2. This change in resistance can serve as an auxiliary tactile reference for the operator to judge the instrument's advancement status, prompting the operator to pay attention to the current advancement and adjust the applied force, but it is not the sole basis for determining the puncture depth or safe position. During advancement, the operator can also assist in judging the external puncture posture by observing the offset position of the bubble in the level at the tail of the operating handle 1.

[0033] In this embodiment, the triangular pyramid piercing end 31 is used for initial entry. The transition fillet radius between adjacent cutting bevels gradually increases from the tip to the proximal end, gradually weakening the cutting action of the edge near the sliding guide section 32. Each cutting edge terminates at the bottom surface of the triangular pyramid piercing end 31. Subsequently, the ellipsoidal sliding guide section 32, without cutting edges or cutting corners, provides support and force guidance when the piercing head touches the wall on the side with a smooth, blunt surface, thus forming a mechanical action relationship along the axial direction that transitions from distal cutting to proximal blunt guidance.

[0034] The miniaturized neck segment 33 and its posterior expanding structure, located proximally on the sliding guide segment 32, form a continuous narrowing and expanding space after the distal guide area. This facilitates the retention of lateral micro-movement, angle adjustment, and wall-sliding margins for the distal guide head, reducing the restriction on guide movement caused by premature contact with the wall by adjacent thicker rod segments. The expanding structure connects proximally to an externally supported main rod with an outer diameter of 7.5 mm to balance the overall rigidity of the device with the transmission of axial thrust and torque. During normal use, this main rod is located outside the pedicle bony passage.

[0035] The triangular pyramidal puncture tip 31, the sliding guide segment 32, and the miniaturized neck segment 33 are adjacent to each other along the axial direction and smoothly transition, forming a continuous action relationship of distal cutting, cutting edge termination, ellipsoidal blunt rounded contact wall guidance, and proximal constraint release. The triangular pyramidal puncture tip 31 undertakes the initial bone entry, the sliding guide segment 32 provides smooth support when contacting the bone wall on the side and receives the reaction force of the bone wall, and the miniaturized neck segment 33 and its posterior gradually expanding structure retain the motion margin for the guiding process and can provide auxiliary resistance change information. The cooperation of the three helps to improve the controllability of the puncture process.

[0036] Example 2: Based on Example 1 above, the maximum outer diameter of the sliding guide section 32 and the diameter of the bottom circumscribed circle are enlarged to 3.0 mm to accommodate the larger size of the lumbar puncture channel.

[0037] The axial height of the puncture end 31 of the triangular pyramid is 0.6 times the diameter of its circumscribed circle, i.e., 1.8 mm. In this embodiment, two adjacent cutting bevels are connected by a smooth transition fillet. The radius of the transition fillet gradually increases from the farthest puncture tip towards the proximal end, so that the edge cutting action near the sliding guide section 32 is gradually weakened and local stress concentration is reduced.

[0038] The outer surface of the sliding guide section 32 is an ellipsoidal smooth convex surface formed by rotating a continuous elliptical arc around the central axis of the puncture head 3. Its cross-section perpendicular to the central axis is circular, and its axial cross-section profile is a continuous smooth elliptical arc. The outer surface is not provided with cutting edges or cutting ridges. The maximum outer diameter of the sliding guide section 32 and the circumcircle diameter of the bottom surface of the triangular pyramid puncture end 31 are both 3.0 mm, and the axial length is 4.5 mm. It tapers smoothly near the maximum outer diameter.

[0039] The minimum outer diameter of the miniaturized neck section 33 is 0.3 mm smaller than the maximum outer diameter of the sliding guide section 32, that is, the diameter at the reduced diameter is 2.7 mm, and the axial transition length at the proximal junction is controlled at 0.8 mm.

[0040] The angle measurement navigation component is an electronic digital display component. The operating handle 1 is made of medical-grade polymer material, and its internal components include a power module, a microcontroller, and a six-axis inertial measurement sensor. A digital display screen is embedded on its outer surface. The power module is electrically connected to and supplies power to the microcontroller, the six-axis inertial measurement sensor, and the digital display screen, respectively. The six-axis inertial measurement sensor and the digital display screen are electrically connected to the microcontroller.

[0041] A calibration button is also provided on the outer surface of the operating handle 1. The remaining mechanical parameters regarding the puncture rod 2 and the outer surface roughness are the same as in Embodiment 1.

[0042] The working principle and beneficial effects of the above technical solution are as follows: Before the surgery officially begins, the patient has been positioned on the operating table. The doctor first positions the puncture navigation tool in a preset initial reference posture, and then presses the calibration button on the surface of the operating handle 1. After receiving the electrical signal triggered by the calibration button, the microcontroller reads the current attitude data from the six-axis inertial measurement sensor and sets the current attitude as the initial attitude reference.

[0043] After calibration, the doctor aligns the puncture head 3 with the needle insertion point and makes an initial incision using the triangular pyramidal puncture end 31. Subsequently, the ellipsoidal sliding guide segment 32 at its proximal end enters the bone tunnel and provides blunt-rounded guidance during lateral contact with the bone wall. During tool advancement, a six-axis inertial measurement sensor continuously collects the puncture tool's posture data and transmits it to the microcontroller. The microcontroller obtains the puncture tool's posture change information based on the change in posture data relative to the initial posture reference and drives the digital display screen to show this posture change information, allowing the operator to assist in judgment and adjustment of the grip posture. The sliding guide segment 32 can create a passive guiding tendency to slide along the wall and move away from the contact side bone wall during lateral contact; the micro-reduced neck segment 33 reduces the restriction of the distal guiding movement by adjacent segments through diameter reduction and provides auxiliary resistance change information through changes in contact area and friction state.

[0044] This embodiment integrates an electronic digital display component and a calibration button on the operating handle 1 to provide a relative posture change reference based on an initial posture baseline for the puncture operation. After establishing the current initial posture baseline through the calibration button, the digital display can provide the operator with posture change information of the puncture tool relative to the initial posture baseline, serving as auxiliary information for adjusting and maintaining the puncture posture, and can be used in conjunction with other intraoperative navigation or image confirmation methods.

[0045] In addition, the transition fillet radius between adjacent cutting bevels gradually increases from the tip to the proximal end, which helps to reduce local stress concentration when the puncture head 3 cuts into hard bone and improves structural reliability; combined with the resistance change trend corresponding to the miniaturized neck segment 33, it can form a complementary operation feedback with the in vitro digital posture display.

[0046] Example 3: The main difference between this example and Example 1 is that the maximum outer diameter of the sliding guide section 32 and the outer diameter of the bottom surface of the triangular pyramid puncture end 31 are both 2.8mm, and the puncture head 3 and the puncture rod 2 adopt a structure of separate processing and then fixed connection.

[0047] The puncture head 3 and puncture rod 2 are respectively processed and formed from medical titanium alloy. Then, the proximal end of the miniaturized neck segment 33 and the distal end of the puncture rod 2 are coaxially fixedly connected by laser welding.

[0048] The puncture rod 2 is a cylindrical titanium alloy rod of equal diameter. The minimum outer diameter of the miniaturized neck section 33 is 0.22 mm smaller than that of the sliding guide section 32, that is, the diameter at the axial reduction point is 2.58 mm. The proximal end of the miniaturized neck section 33 gradually expands its outer diameter through an outwardly convex arc transition surface, so that its end diameter is restored to 2.8 mm, thereby achieving misalignment-free, equal-diameter alignment and welding with the outer diameter of the puncture rod 2.

[0049] The operating handle 1 has an axially fitted opening at its front end. The proximal surface of the puncture rod 2 has a transverse positioning through hole. The proximal end of the puncture rod 2 is pressed into the front opening of the operating handle 1 through an interference fit, and a rigid anti-torsion fixation is achieved through a pin structure. As an optional method in this embodiment, a screw or injection-molded insert can also be used to achieve rigid anti-torsion fixation.

[0050] The working principle and beneficial effects of the above technical solution are as follows: In clinical use, the operator applies axial thrust and torsional correction force to the instrument via the operating handle 1. Because the proximal end of the puncture rod 2 and the operating handle 1 employ a composite locking structure of interference fit and transverse pin, the axial force and torque applied by the handle can be stably transmitted to the puncture rod 2, reducing the possibility of relative slippage. TC4 ELI titanium alloy has a high specific strength, which, combined with the aforementioned rod structure, provides the instrument with corresponding load-bearing and force-transmitting capabilities.

[0051] Once the puncture head 3 enters the bony passage of the pedicle, the triangular cone puncture end 31 provides initial incision guidance. If the open path deviates at an angle and contacts the cortical bone wall, the sliding guide segment 32, located proximal to the triangular cone puncture end 31, forms lateral contact with the cortical bone wall with a smooth, ellipsoidal convex surface without cutting edges. This surface is polished, making it less likely to form a continuous cutting fulcrum and facilitating relative sliding along the bone wall. The normal reaction force generated by the cortical bone wall helps the puncture head 3 to passively guide away from the contact side of the bone wall; the reduced diameter area of ​​the miniaturized neck segment 33 helps to reduce the restriction of distal guiding movement by the adjacent rod segment adhering to the wall. When the main contact area between the tool and the bone transitions from the maximum outer diameter of the sliding guide segment 32 to the narrowed area of ​​the miniaturized neck segment 33, the contact area and friction state may change accordingly, and the axial resistance may change accordingly and be transmitted to the operator's hand via the puncture rod 2 as an auxiliary tactile reference. As the instrument continues to advance, the convex arc transition surface at the proximal end of the miniaturized cervical segment 33 gradually comes into contact with the surrounding bone, allowing the resistance to recover gradually, thus forming a more continuous mechanical transition.

[0052] This embodiment uses medical-grade titanium alloy and connects the puncture head 3 and puncture rod 2 via coaxial welding. The convex arc transition surface at the proximal end of the miniaturized neck segment 33 gradually restores its outer diameter to match that of the puncture rod 2, reducing the geometric steps and stress concentration at the connection point and creating a smoother friction transition after the change in resistance. The interference fit between the operating handle 1 and the puncture rod 2, as well as the transverse pin anti-torsion structure, helps improve the stability of axial force and torque transmission.

[0053] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. Other modifications can be easily made by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A pedicle puncture navigation tool with automatic deviation correction and anti-wall-breaking function, comprising an operating handle (1) and a puncture rod (2) connected to the operating handle (1), wherein a puncture head (3) is provided at the distal end of the puncture rod (2); characterized in that, The puncture head (3) includes, from distal to proximal, a triangular pyramidal puncture end (31), a sliding guide section (32), and a miniaturized neck section (33) that are axially adjacent and smoothly connected. The bottom surface of the triangular pyramid puncture end (31) is connected to the distal end of the sliding guide section (32). The triangular pyramid puncture end (31) includes three cutting bevels of equal area that are circumferentially distributed around the central axis of the puncture head (3). The three cutting bevels intersect to form a puncture tip located on the central axis. Two adjacent cutting bevels intersect to form a cutting edge. The proximal end of each cutting edge terminates at the bottom surface. The outer surface of the sliding guide section (32) is a smooth convex ellipsoidal surface that is rotationally symmetrical about the central axis of the puncture head (3), and the outer surface is a blunt round guide surface without cutting edge; the maximum outer diameter of the sliding guide section (32) is equal to the diameter of the circumcircle of the bottom surface, and it tapers smoothly at the proximal end of the maximum outer diameter part. The miniaturized neck segment (33) is located at the proximal end of the maximum outer diameter portion of the sliding guide segment (32). The minimum outer diameter of the miniaturized neck segment (33) is smaller than the maximum outer diameter of the sliding guide segment (32). The proximal end of the miniaturized neck segment (33) is smoothly connected to the puncture rod (2).

2. The pedicle puncture navigation tool with automatic deviation correction and anti-wall-breaking function according to claim 1, characterized in that, The axial height of the puncture end (31) of the triangular pyramid is 0.6 to 0.9 times the diameter of the circumscribed circle of its base; and the axial height of the puncture end (31) of the triangular pyramid is 1.8 mm to 2.2 mm; two adjacent cutting bevels are connected by a smooth transition fillet, and the radius of the transition fillet gradually increases from the puncture tip to the proximal end.

3. The pedicle puncture navigation tool with automatic deviation correction and anti-wall-breaking function according to claim 1, characterized in that, The axial length of the sliding guide section (32) is 3.0 mm to 5.0 mm.

4. The pedicle puncture navigation tool with automatic deviation correction and anti-wall-breaking function according to claim 1, characterized in that, The minimum outer diameter of the miniaturized neck section (33) is 0.2 mm to 0.3 mm smaller than the maximum outer diameter of the sliding guide section (32); the junction of the miniaturized neck section (33) and the sliding guide section (32) at its distal end is smoothly connected by a transition fillet.

5. The pedicle puncture navigation tool with automatic deviation correction and anti-wall-breaking function according to claim 4, characterized in that, The miniaturized neck segment (33) gradually thickens from the distal end to the proximal end to form a first gradually expanding segment. The outer diameter of the proximal end of the first gradually expanding segment is equal to the maximum outer diameter of the sliding guide segment (32). The axial length of the first gradually expanding segment is 25 mm to 30 mm. The proximal end of the first gradually expanding segment continues to thicken smoothly through a gradually expanding connecting segment and connects to the main rod of the puncture rod (2). The outer diameter of the main rod is 7 mm to 8 mm.

6. The pedicle puncture navigation tool with automatic deviation correction and anti-wall-breaking function according to any one of claims 1 to 5, characterized in that, The puncture head (3) and the puncture rod (2) are integrally formed from medical-grade metal material; except for the three cutting bevels of the triangular pyramidal puncture end (31), the outer surfaces of the sliding guide section (32), the miniaturized neck section (33) and the puncture rod (2) are all polished, and the surface roughness Ra is not greater than 0.2μm.

7. The pedicle puncture navigation tool with automatic deviation correction and anti-wall-breaking function according to claim 1, characterized in that, The operating handle (1) is also integrated with an angle measurement navigation component, which is used to indicate the tilt state of the puncture tool relative to the direction of gravity, or to monitor the attitude change of the puncture tool relative to the initial attitude reference.

8. The pedicle puncture navigation tool with automatic deviation correction and anti-wall-breaking function according to claim 7, characterized in that, The angle measurement navigation component is a purely mechanical level, which is embedded in the tail end face of the operating handle (1). The purely mechanical level is a universal circular level or a dual-axis bubble level.

9. The pedicle puncture navigation tool with automatic deviation correction and anti-wall-breaking function according to claim 7, characterized in that, The angle measurement navigation component is an electronic digital display component, which includes a power module, a microcontroller and a six-axis inertial measurement sensor encapsulated inside the operating handle (1), and a display screen disposed on the outer surface of the operating handle (1); the power module is electrically connected to and supplies power to the microcontroller, the six-axis inertial measurement sensor and the display screen respectively, and the six-axis inertial measurement sensor and the display screen are electrically connected to the microcontroller respectively.

10. The pedicle puncture navigation tool with automatic deviation correction and anti-wall-breaking function according to claim 9, characterized in that, The operating handle (1) is also provided with a calibration button that is electrically connected to the microcontroller; the microcontroller is used to set the current attitude data of the six-axis inertial measurement sensor as the initial attitude reference when the calibration button is triggered, and to receive the attitude data collected by the six-axis inertial measurement sensor during the puncture process, obtain the attitude change information of the puncture tool according to the change of the attitude data relative to the initial attitude reference, and drive the display screen to display the attitude change information.

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