Surgical screwdriver

Abstract

The invention discloses a screwdriver for an operation. The screwdriver for the operation comprises a screwdriver body and a breaking groove, one end of the screwdriver body is provided with a driving part, and the driving part is suitable for being matched with a fastener for the operation; the breaking groove is formed in the circumferential direction of the screwdriver body, and the maximum torque borne by the screwdriver body at the breaking groove is smaller than the maximum torque borne by the driving part. According to the screwdriver for the operation, the breaking groove is formed in the screwdriver body, a weak area is formed in the breaking groove, the maximum torque capable of being borne by the breaking groove is smaller than the maximum torque capable of being borne by the driving part, and when the screwdriver is used for locking and fixing operation, if the force is too large, the weak area is formed in the breaking groove; when the driving part is locked and fixed, irreversible deformation damage or breakage occurs at the breaking groove in advance, so that the driving part is protected, the driving part is prevented from being cracked in advance during locking and fixing operation, the risk of an operation is reduced, and the practicability and the reliability of a product are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of medical instruments, and in particular relates to a surgical screwdriver. Background Art

[0002] Pedicle screw fixation is a commonly used spinal fixation surgery. Whether it is scoliosis, correction, or lifting and reduction surgery, a screwdriver will be used to lock and fix the pedicle screws.

[0003] In the related art, in order to achieve a locking state, the doctor may use excessive force, which may cause the driving structure in the screwdriver that cooperates with the pedicle screw to break. If the broken debris falls into the patient's body and needs to be found and confirmed, it will not only easily cause infection to the patient, but also cause delays or failures in the operation. Summary of the invention

[0004] The present invention is based on the inventor's discovery and understanding of the following facts and problems:

[0005] The inventors realized that during spinal fixation surgery, if the locking force when the doctor is locking the screw plug is too small, the screw plug, connecting rod and pedicle screw used in the spinal fixation surgery may become loose during the intraoperative dilation and pressurization operation or the patient's postoperative recovery process, thereby causing surgical risks and causing additional harm and pain to the patient.

[0006] The inventors also realized that there is a torque limiting handle in the related technology, but after the pedicle screw is locked and fixed with the torque limiting handle, it is not the locking state that the doctor wants. At this time, the doctor will still use an ordinary screwdriver to lock and fix the pedicle screw. The torque is unknown and uncontrollable. If too much force is used, the driving structure of the screwdriver will be damaged and cracked.

[0007] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0008] To this end, an embodiment of the present invention provides a surgical screwdriver, which can prevent damage to the driving structure of the screwdriver, reduce the risk of surgery, and improve the practicality and reliability of the product.

[0009] The surgical screwdriver of the embodiment of the present invention comprises: a screwdriver body, one end of which has a driving portion, the driving portion being suitable for cooperating with a surgical fastener; a breaking groove, the breaking groove being arranged along the circumference of the screwdriver body, the maximum torque that the screwdriver body can withstand at the breaking groove is smaller than the maximum torque that the driving portion can withstand.

[0010] The surgical screwdriver of the embodiment of the present invention has a breaking groove on the screwdriver body to form a weak area at the breaking groove. The maximum torque that the breaking groove can withstand is smaller than the maximum torque that the driving part can withstand. When the screwdriver is used for locking and fixing operations, if too much force is used, the breaking groove will first undergo irreversible deformation, damage or breakage, thereby protecting the driving part and preventing the driving part from breaking first during the locking and fixing operation, reducing the risk of surgery and improving the practicality and reliability of the product.

[0011] In some embodiments, the cross-section of the broken groove includes a first arc segment, and both sides of the first arc segment are connected to the outer wall surface of the screwdriver body; or, the cross-section of the broken groove includes a second arc segment and a straight line segment, and both sides of the second arc segment are connected to the outer wall surface of the screwdriver body through the straight line segment.

[0012] In some embodiments, the radius of the first arc segment is 0.2 mm to 6 mm; or, the radius of the second arc segment is 0.2 mm to 2 mm; or, the angle between the two straight line segments on both sides of the second arc segment is 0 degree to 150 degrees.

[0013] In some embodiments, the break groove is arranged close to the driving part; and / or the break groove is a circular annular groove; and / or the maximum torque that the screwdriver body can withstand at the break groove is 70% to 98% of the maximum torque that the driving part can withstand; and / or the cross-section of the driving part is a polygon or a bisecting line; and / or the end of the driving part has a guide section, the cross-sectional size of the guide section gradually decreases from the end close to the driving part to the end away from the driving part, and the length of the guide section in the axial direction of the screwdriver body is 0.1mm to 1mm; and / or the torsional section coefficient Wc of the screwdriver body at the break groove is the torsional section coefficient Wc of the driving part. 13 70% to 98%.

[0014] In some embodiments, the cross section of the driving portion is a regular hexagon, and the torsional section coefficient W of the driving portion is 13 Satisfies the following formula:

[0015] W 13 =1.0826*R 3

[0016] Wherein, R is the radius of the circumscribed circle of the regular hexagon;

[0017] The torsional section coefficient Wc at the fracture groove satisfies the following formula:

[0018]

[0019] Wherein, C is the minimum diameter at the breaking groove;

[0020] Or, the cross section of the driving part is a positive multi-petal shape, and the torsional section coefficient W of the driving part is 13 Satisfies the following formula:

[0021]

[0022] Wherein, D is the radius of the large circle of the regular multi-petal shape, Z is the number of petals of the regular multi-petal shape, b is the width of the petal portion, and d is the diameter of the small circle in the regular multi-petal shape;

[0023] The torsional section coefficient Wc at the fracture groove satisfies the following formula:

[0024]

[0025] Wherein, C is the minimum diameter at the breaking groove.

[0026] In some embodiments, the end of the screwdriver body away from the driving portion has a handle, and the handle is fixedly connected to the screwdriver body; or, the end of the screwdriver body away from the driving portion has a connecting portion, and the connecting portion is suitable for quick disassembly and assembly with a connecting structure, and the connecting portion includes an annular groove and a plurality of mating surfaces arranged along the circumference of the screwdriver body, and the annular groove is located on the side of the mating surface close to the driving portion, and the annular groove is suitable for limiting the connecting structure in the axial direction of the screwdriver body.

[0027] In some embodiments, the screwdriver body includes an inner core rod, an outer sleeve and an indicator sleeve, the outer sleeve and the indicator sleeve are fixedly mounted on the inner core rod, the drive portion and the breaking groove are both arranged on the inner core rod, the outer sleeve has a first identification portion, and the indicator sleeve has a second identification portion; after torque is applied to the inner core rod, the inner core rod will be deformed so that there is a relative angular displacement between the indicator sleeve and the outer sleeve, and the relative positions of the first identification portion and the second identification portion in the circumferential direction of the inner core rod are suitable for identifying the relative angular displacement of the indicator sleeve and the outer sleeve.

[0028] In some embodiments, a gap between an end of the outer sleeve away from the indicator sleeve and the inner core rod is smaller than a gap between an end of the outer sleeve close to the indicator sleeve and the inner core rod.

[0029] In some embodiments, the inner hole of the outer sleeve includes a plurality of sections, the inner diameters of the plurality of sections gradually increase along the direction in which the outer sleeve approaches the indicator sleeve, and the length of the section with the smallest inner diameter is 2 mm to 30 mm; and / or, the inner diameter of the end of the outer sleeve away from the indicator sleeve is 0.01 mm to 0.2 mm larger than the outer diameter of the inner core rod at its corresponding position, and the inner diameter of the end of the outer sleeve close to the indicator sleeve is 0.3 mm to 10 mm larger than the outer diameter of the inner core rod at its aligned position; and / or, the indicator sleeve is located at the end of the outer sleeve away from the driving portion; and / or, the end of the outer sleeve away from the indicator sleeve is fixedly connected to the inner core rod, and the end of the indicator sleeve away from the outer sleeve is fixedly connected to the inner core rod.

[0030] In some embodiments, the outer sleeve has an indicator disk, the first identification portion is arranged on the indicator disk, the indicator sleeve has an indicator arm rod, the second identification portion is arranged on the indicator arm rod, the number of the first identification portions is multiple, and the multiple first identification portions are arranged on the indicator disk at circumferential intervals along the inner core rod.

[0031] In some embodiments, the indicator plate has two limiting parts, and the two limiting parts are arranged on the indicator plate at intervals along the circumference of the inner core rod, the indicating arm rod and the plurality of first identification parts are all located between the two limiting parts, and the limiting parts and the indicating arm rod are relatively arranged in the circumferential direction of the inner core rod, suitable for limiting the relative angular displacement of the indicating arm rod and the outer sleeve; and / or, the indicator plate is fan-shaped, and the angle between the two side edges of the indicating plate in the circumferential direction of the inner core rod is 25 degrees to 90 degrees; and / or, it also includes a gasket, which is located between the outer sleeve and the indicating sleeve; and / or, the outer sleeve has a hollow hole group, and the hollow hole group includes a plurality of hollow holes arranged along the circumference of the outer sleeve, and the number of the hollow hole group is one, or a plurality of hollow holes arranged along the axial direction of the outer sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic structural diagram of a surgical screwdriver according to an embodiment of the present invention.

[0033] Figure 2 It is a schematic cross-sectional view of a surgical screwdriver according to an embodiment of the present invention.

[0034] Figure 3 Schematic diagram of the structure of the breaking groove in the embodiment of the present invention.

[0035] Figure 4 It is a schematic structural diagram of a breaking groove in another embodiment of the present invention.

[0036] Figure 52 is a schematic structural diagram of a cross section of a driving portion in an embodiment of the present invention.

[0037] Figure 6 1 is a schematic structural diagram of a cross section of a driving portion in another embodiment of the present invention.

[0038] Figure 7 2 is a schematic structural diagram of a cross section of a driving portion in another embodiment of the present invention.

[0039] Figure 8 2 is a schematic structural diagram of a cross section of a driving portion in another embodiment of the present invention.

[0040] Fig. 9 2 is a schematic structural diagram of a cross section of a driving portion in another embodiment of the present invention.

[0041] Fig.10 It is a structural schematic diagram of the guide section in an embodiment of the present invention.

[0042] Fig.11 It is a schematic diagram of the connection structure between the handle and the screwdriver body in an embodiment of the present invention.

[0043] Fig.12 2 is a schematic diagram of the connection structure between the handle and the screwdriver body from another perspective in an embodiment of the present invention.

[0044] Fig.13 It is a schematic structural diagram of a surgical screwdriver according to another embodiment of the present invention.

[0045] Fig.14 It is a schematic cross-sectional view of a surgical screwdriver according to another embodiment of the present invention.

[0046] Fig.15 Schematic diagram of the structure of the connecting portion of an embodiment of the present invention.

[0047] Fig.16 It is a structural schematic diagram of the connecting portion of an embodiment of the present invention from another perspective.

[0048] Fig.17 1 is a schematic diagram of the structure of a screwdriver body in an embodiment of the present invention.

[0049] Fig.18 It is a schematic cross-sectional structural diagram of a screwdriver body in an embodiment of the present invention.

[0050] Fig.19 Schematic diagram of the structure of the indicator plate and the indicator arm in the embodiment of the present invention.

[0051] Fig. 20 2 is a schematic structural diagram of the indicator plate and the indicator arm in another perspective in the embodiment of the present invention.

[0052] Fig.21It is a schematic diagram of the cross-sectional structure of a driving part of an embodiment of the present invention that is a regular hexagon.

[0053] Fig. 22 It is a schematic diagram of the cross-sectional structure of a driving part of an embodiment of the present invention that is a positive multi-petal shape.

[0054] Reference numerals:

[0055] 100. Screwdriver for surgery;

[0056] 1. The screwdriver body;

[0057] 11. Inner core rod; 12. Outer sleeve; 121. Indicator plate; 122. First identification part; 123. Position limiting part; 13. Driving part; 14. Indicator sleeve; 141. Indicator arm rod; 142. Second identification part; 15. Guide section; 16. Connection point; 17. Hollow hole; 18. Connection part; 181. Matching surface; 182. Ring groove; 19. Washer;

[0058] 2. Broken groove; 21. First arc segment; 22. Second arc segment; 23. Straight line segment;

[0059] 3. Handle. DETAILED DESCRIPTION

[0060] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0061] The following combination Figures 1 to 22 The structure of the embodiment of the present invention is further described in detail.

[0062] like Figure 1 and Figure 2 As shown, a surgical screwdriver 100 according to an embodiment of the present invention comprises a screwdriver body 1 and a breaking groove 2. One end of the screwdriver body 1 has a driving portion 13, and the driving portion 13 is suitable for cooperating with a surgical fastener.

[0063] It is understandable that the fastener may be a pedicle screw or other structural member used in a surgical operation that needs to be tightened by a screwdriver. The driving portion 13 has a shape feature that matches the driving structural feature of the fastener. When tightening, the driving portion 13 and the driving structural feature of the fastener are matched by a plug-in method, so that the force applied to the screwdriver acts on the fastener to lock and fix the fastener.

[0064] The breaking groove 2 is arranged along the circumference of the screwdriver body 1 , and the maximum torque that the screwdriver body 1 can withstand at the breaking groove 2 is smaller than the maximum torque that the driving part 13 can withstand.

[0065] It should be understood that when a screwdriver is used to lock and fix a fastener, the screwdriver body 1 is twisted, and each position of the screwdriver body 1 is in a shear stress state. When the maximum shear stress of a certain cross section approaches or exceeds the allowable shear stress of the material, the position is more likely to be damaged. The maximum shear stress exists in the cross section where the maximum torque is located, that is, the dangerous point of the dangerous cross section. Therefore, in the embodiment of the present invention, a break groove 2 is provided on the screwdriver body 1 to form a weak area in the area outside the drive part 13 of the screwdriver body 1. By reducing the maximum torque that the screwdriver body 1 can withstand at the break groove 2, and making the maximum torque that the break groove 2 can withstand less than the maximum torque that the drive part 13 can withstand, the drive part 13 is protected.

[0066] When using a screwdriver for locking and fixing operations, if too much force is applied, the breaking groove 2 will first undergo irreversible deformation, damage or breakage, thereby ensuring that the drive part 13 will not first break and produce debris during the locking and fixing operation, thereby reducing the risk of the operation and improving the practicality and reliability of the product.

[0067] In some embodiments, Figure 3 and Figure 4 As shown, the broken groove 2 is an annular groove 182, and the cross-section of the broken groove 2 includes a first arc segment 21, and the two sides of the first arc segment 21 are connected to the outer wall surface of the screwdriver body 1; or, the cross-section of the broken groove 2 includes a second arc segment 22 and a straight line segment 23, and the two sides of the second arc segment 22 are connected to the outer wall surface of the screwdriver body 1 through the straight line segment 23.

[0068] In the embodiment of the present invention, the cross-section of the breaking groove 2 is designed. The cross-section of the breaking groove 2 can be an arc shape, or a combination of an arc and a straight line. Finite element analysis has verified that the problem of stress concentration at the breaking groove 2 can be reduced, ensuring that the fracture is more neat and the end face of the fracture is smoother.

[0069] When the screwdriver body 1 breaks at the breaking groove 2, the fracture is a neat circle, which is flat and neat, and will not cause cracking and debris. At this time, the broken part can be taken out without looking for tool debris, which reduces waiting time and reduces surgical risks.

[0070] The embodiment of the present invention adopts two different structural forms, which can better process the structure of the broken groove 2 according to the maximum torque that can be borne. Since the maximum torque that can be borne is positively correlated with the diameter of the cross-section circle at the broken groove 2, when the diameter of the screwdriver body 1 is constant, different structural forms of the broken groove 2 can be selected because the maximum torque that needs to be borne is different. When the difference between the cross-section circle diameter of the broken groove 2 and the diameter of the screwdriver body 1 is small, only the structural form of the first arc segment 21 can be adopted. When the difference between the cross-section circle diameter of the broken groove 2 and the diameter of the screwdriver body 1 is large, a combination of the second arc segment 22 and the straight line segment 23 can be adopted, and a smooth transition connection between segments can be achieved.

[0071] Furthermore, when the cross section of the breaking groove 2 is only in the shape of a circular arc, that is, when it only includes the first circular arc segment 21 , the radius of the first circular arc segment 21 is 0.2 mm to 6 mm.

[0072] Specifically, the radius Ry of the first arc segment 21 may be 0.2 mm, 0.34 mm, 1.7 mm, 2.96 mm, 3.44 mm, 4.3 mm, 5 mm or 6 mm.

[0073] When the radius of the first arc segment 21 is too small and less than 0.2 mm, it will easily lead to problems such as great difficulty in processing, uneven transition between the first arc segment 21 and the outer wall of the screwdriver body 1, and too shallow breaking groove 2. When the radius of the first arc segment 21 is too large and greater than 6 mm, it will cause the size of the breaking groove 2 in the axial direction of the screwdriver body 1 to be large, which will easily lead to an uneven cross-section of the breaking groove 2 when it breaks.

[0074] When the cross-section of the breaking groove 2 is in the form of a combination of an arc and a straight line, that is, when the cross-section of the breaking groove 2 includes a second arc segment 22 and a straight line segment 23, the radius Rx of the second arc segment 22 is 0.2 mm to 2 mm, and the angle between the two straight line segments 23 on both sides of the second arc segment 22 is 0 degrees to 150 degrees.

[0075] Specifically, the radius of the second arc segment 22 can be 0.2mm, 0.45mm, 0.68mm, 1.2mm, 1.44mm, 1.8mm or 2mm. When the radius of the second arc segment 22 is too small and less than 0.2mm, it is easy to cause problems such as difficult processing, uneven transition between the first arc segment 21 and the outer wall surface of the screwdriver body 1, and too shallow fracture groove 2. When the radius of the second arc segment 22 is too large and greater than 2mm, it is inconvenient to use with the straight segment 23 when the difference between the cross-sectional circular diameter of the fracture groove 2 and the diameter of the screwdriver body 1 is large.

[0076] The included angle between the two straight segments 23 can be 0 degrees, 24 degrees, 35.5 degrees, 60 degrees, 87 degrees, 90 degrees, 120 degrees or 150 degrees. If the included angle between the two straight segments 23 is not less than 0 degrees, the broken groove 2 can be prevented from being in a closed shape. When the included angle m between the two straight segments 23 is greater than 150 degrees, the size of the broken groove 2 in the axial direction of the screwdriver body 1 will be large, and the cross-section of the broken groove 2 will be uneven when broken.

[0077] Furthermore, the maximum torque that the screwdriver body 1 can withstand at the breaking groove 2 is 70% to 98% of the maximum torque that the driving part 13 can withstand.

[0078] The maximum torque that the screwdriver body 1 can withstand at the breaking groove 2 can be 70%, 75%, 77%, 86%, 90%, 95.6% or 98% of the maximum torque that the driving part 13 can withstand.

[0079] When the maximum torque that the screwdriver body 1 can withstand at the breaking groove 2 is less than 70% of the maximum torque that the driving part 13 can withstand, the performance of the screwdriver will be affected, resulting in excessive performance loss of the screwdriver, affecting the normal use of the screwdriver, and easily causing it to break during normal use. When the maximum torque that the screwdriver body 1 can withstand at the breaking groove 2 is greater than 98% of the maximum torque that the driving part 13 can withstand, it is easy to cause the breaking groove 2 of the screwdriver body 1 to fail to break before the driving part 13 collapses due to deviations in the holding method or the force application method, resulting in the failure of the protection function of the breaking groove 2.

[0080] Furthermore, the breaking groove 2 is arranged close to the driving part 13. By constraining the positions of the breaking groove 2 and the driving part 13, the forces on the breaking groove 2 and the driving part 13 can be more consistent, thereby avoiding the failure of the protection function of the breaking groove 2 due to the influence of factors such as the holding method of the screwdriver body 1, the force direction, or the elastic deformation of the screwdriver body 1.

[0081] like Figures 5 to 9 As shown, optionally, the cross section of the driving portion 13 is a polygon or a bisecting line.

[0082] The driving portion 13 is a columnar structure with a uniform cross-section. In order to enable the driving portion 13 to cooperate with the driving structural features of the fastener to lock and fix the fastener, a plurality of abutment surfaces are required between the driving portion 13 and the driving structural features of the fastener. The abutment surfaces can be plane surfaces or arc surfaces. When the driving structural features of the driving portion 13 and the fastener cooperate, the driving structural features of the driving portion 13 and the fastener can be constrained to rotate relative to each other in the circumferential direction of the screwdriver body 1.

[0083] For example, the cross section of the driving portion 13 is a regular quadrilateral, a regular pentagon, a regular hexagon (such as Figure 5 shown).

[0084] For another example, the cross section of the driving portion 13 is a hexagonal flower shape (eg Figure 6 As shown), regular hexagonal point convex shape (as shown Figure 7 as shown), TORX shape (as shown Figure 8 As shown), positive multi-petal shape (as Fig. 9 (as shown) are the bisector lines of the central symmetrical section.

[0085] like Fig.10 As shown, in some embodiments, the end of the driving portion 13 has a guide section 15, the cross-sectional size of the guide section 15 gradually decreases from one end close to the driving portion 13 to the end away from the driving portion 13, and the length of the guide section 15 in the axial direction of the screwdriver body 1 is 0.1 mm to 1 mm.

[0086] It should be understood that when the driving portion 13 and the driving structural features of the fastener cooperate, if the gap between the two is too small, it is difficult to quickly achieve plug-in. The embodiment of the present invention provides a guide section 15 at the end of the driving portion 13, and the guide section 15 can be used to quickly achieve guidance and positioning with the driving structural features of the fastener, making it easier to plug the driving portion 13 and the driving structural features of the fastener.

[0087] The length L of the guide section 15 in the axial direction of the screwdriver body 1 can be 0.1 mm, 0.2 mm, 0.33 mm, 0.5 mm, 0.75 mm or 1 mm. If the length of the guide section 15 in the axial direction of the screwdriver body 1 is less than 0.1 mm, it is difficult to play a guiding role. When the length of the guide section 15 in the axial direction of the screwdriver body 1 is greater than 1 mm, it is easy to cause the effective plug-in length of the driving structure feature of the driving part 13 and the fastener to be limited, affecting the cooperation between the two, and easily causing damage to the driving part 13 or the driving structure of the fastener.

[0088] Optionally, the guide section 15 may be a straight chamfer or an arc chamfer provided at the end of the driving portion 13 .

[0089] like Figure 1 , Figure 2 , Fig.11 and Fig.12 As shown, in some embodiments, the end of the screwdriver body 1 away from the driving portion 13 has a handle 3, and the handle 3 is integrally connected to the screwdriver body 1.

[0090] The handle 3 can be integrally formed with the screwdriver body 1, welded and fixed, or fixedly connected by connecting pieces such as rivets and bolts, etc. The operation of assembling the handle 3 during surgery can be reduced, the operation is simple, and the operation time is saved.

[0091] Furthermore, the length extension direction of the handle 3 is orthogonal to the length extension direction of the screwdriver body 1 , and the handle 3 and the screwdriver body 1 are arranged in a T shape.

[0092] like Figures 13 to 16 As shown, in some embodiments, the end of the screwdriver body 1 away from the driving portion 13 has a connecting portion 18, and the connecting portion 18 is suitable for quick disassembly and assembly with the connecting structure. The connecting portion 18 includes an annular groove 182 and a plurality of mating surfaces 181 arranged along the circumference of the screwdriver body 1, and the annular groove 182 is located on the side of the mating surface 181 close to the driving portion 13, and the annular groove 182 is suitable for limiting the connecting structure in the axial direction of the screwdriver body 1.

[0093] The multiple mating surfaces 181 in the connecting portion 18 form a columnar structure that cooperates with the connecting structure, which can limit the connection structure from rotating relative to the screwdriver body 1 around the axial direction of the screwdriver body 1. The annular groove 182 can cooperate with the limiting parts such as balls, limiting columns, and limiting blocks on the connecting structure. When the limiting part is stuck in the annular groove 182, it can limit the connection structure from moving relative to the screwdriver body 1 along the axial direction of the screwdriver body 1.

[0094] Optionally, the connection structure in the embodiment of the present invention is a handle that is separately provided with the screwdriver body 1. After the handle and the screwdriver body 1 are connected together, the screwdriver body 1 can be twisted by holding the handle during surgery. The handle has a countersunk hole and limiting parts such as balls, limiting columns, and limiting blocks that extend and retract along the radial direction of the countersunk hole. After the screwdriver body 1 and the handle are quickly connected, multiple mating surfaces 181 are fitted and abutted against the wall of the countersunk hole, and limiting parts such as balls, limiting columns, and limiting blocks are stuck in the countersunk groove.

[0095] Optionally, the number of the mating surfaces 181 may be 2, 4, 5 or 6.

[0096] In the related art, when doctors use screwdrivers to perform locking and fixing operations, they usually rely on experience to judge the size of the torque. However, when performing long-term operations that require high intensity and high concentration, it is easy to cause surgical risks due to misjudgment and operational errors.

[0097] like Figures 17 to 20 As shown, in some embodiments, the screwdriver body 1 includes an inner core rod 11, an outer sleeve 12 and an indicating sleeve 14, the outer sleeve 12 and the indicating sleeve 14 are both fixedly mounted on the inner core rod 11, the driving portion 13 and the breaking groove 2 are both arranged on the inner core rod 11, the outer sleeve 12 has a first identification portion 122, and the indicating sleeve 14 has a second identification portion 142; after torque is applied to the inner core rod 11, the inner core rod 11 will be deformed so that there is a relative angular displacement between the indicating sleeve 14 and the outer sleeve 12, and the relative positions of the first identification portion 122 and the second identification portion 142 in the circumferential direction of the inner core rod 11 are suitable for identifying the relative angular displacement of the indicating sleeve 14 and the outer sleeve 12.

[0098] In the screwdriver body 1 of the embodiment of the present invention, the inner core rod 11 is the main rod body, the driving part 13 and the breaking groove 2 are both arranged on the inner core rod 11, the outer sleeve 12 and the indicating sleeve 14 themselves do not bear shear stress, but the outer sleeve 12 and the indicating sleeve 14 have a connection point 16 with the inner core rod 11, and the two ends of the inner core rod 11 are subjected to two force couples in the plane perpendicular to the axis. The two force couples are equal in magnitude and opposite in direction. Under the action of this pair of force couples, each cross section of the inner core rod 11 rotates relative to the axis. At this time, there is a relative angular displacement between any two cross sections, that is, the torsion angle. The larger the force couple, the larger the torsion angle.

[0099] Therefore, there is also a torsion angle between the two cross sections on the inner core rod 11 corresponding to the two connection points 16, so that the outer sleeve 12 and the indicator sleeve 14 rotate relatively around the axis of the inner core rod 11 and generate a torsion angle.

[0100] The embodiment of the present invention reflects the torsion angle between the outer sleeve 12 and the indicator sleeve 14 by the change of the relative positions of the first identification part 122 and the second identification part 142 in the circumferential direction of the inner core rod 11, and can more intuitively reflect the size of the force couple acting on the inner core rod 11. When the doctor is performing the operation, the doctor can be informed of the current torque size so that he or she has a clear idea of ​​the torque. There is no need to repeatedly pressurize and lock, and no need for the assistance of the torque limiting handle 3, thereby saving tool costs.

[0101] Optionally, one end of the outer sleeve 12 away from the indicator sleeve 14 is fixedly connected to the inner core rod 11 , and one end of the indicator sleeve 14 away from the outer sleeve 12 is fixedly connected to the inner core rod 11 .

[0102] It is understandable that the outer sleeve 12 and the inner core rod 11, and the indicator sleeve 14 and the inner core rod 11 can be connected and fixed by welding, riveting, etc., or can be connected by limiting members or connectors such as limiting pins, limiting blocks, screws, etc.

[0103] Since the inner core rod 11 needs to withstand sufficient torque, the inner core rod 11 must meet the stiffness requirements. In order to ensure that there is a clearly observable torsion angle between the outer sleeve 12 and the indicator sleeve 14, there needs to be a sufficient distance between the connection points 16 between the outer sleeve 12 and the inner core rod 11, and between the connection points 16 between the indicator sleeve 14 and the inner core rod 11, to ensure that after a certain magnitude of force couple is applied to the inner core rod 11, there is a certain magnitude of torsion angle between the two cross sections on the inner core rod 11 at positions corresponding to the two connection points 16.

[0104] The distance between the two connection points 16 can be determined according to the size of the force couple to be warned, the material of the inner core rod 11 and the length of the outer sleeve 12 .

[0105] The arrangement of the outer sleeve 12 and the inner core rod 11 in the embodiment of the present invention will not affect the performance of the screwdriver body 1 and will not limit the torque of the screwdriver body 1 .

[0106] Further, the gap between the end of the outer sleeve 12 away from the indicator sleeve 14 and the inner core rod 11 in the embodiment of the present invention is smaller than the gap between the end of the outer sleeve 12 close to the indicator sleeve 14 and the inner core rod 11. The length of the outer sleeve 12 is longer than that of the indicator sleeve 14, and the distance between the two connection points 16 is mainly adjusted by the outer sleeve 12. The end of the outer sleeve 12 away from the indicator sleeve 14 is fixedly connected to the inner core rod 11. Appropriately reducing the gap between the end of the outer sleeve 12 away from the indicator sleeve 14 and the inner core rod 11 makes it more convenient to assemble and connect, and ensures that the end of the outer sleeve 12 away from the indicator sleeve 14 fits the inner core rod 11 better. Appropriately increasing the gap between the end of the outer sleeve 12 close to the indicator sleeve 14 and the inner core rod 11 can provide a relatively sufficient free space between the outer sleeve 12 and the inner core rod 11, avoiding interference between the outer sleeve 12 and the inner core rod 11, and affecting the performance of each component.

[0107] Optionally, the inner diameter of the end of the outer sleeve 12 away from the indicator sleeve 14 is 0.01mm to 0.2mm larger than the outer diameter of the inner core rod 11 at its corresponding position, and the inner diameter of the end of the outer sleeve 12 close to the indicator sleeve 14 is 0.3mm to 10mm larger than the outer diameter of the inner core rod 11 at its corresponding position.

[0108] It should be understood that the inner diameter of the end of the outer sleeve 12 away from the indicator sleeve 14 is 0.01mm, 0.03mm, 0.07mm, 0.12mm, 0.14mm, 0.175mm or 2mm larger than the outer diameter of the inner core rod 11 at the corresponding position. When the difference between the inner diameter of the end of the outer sleeve 12 away from the indicator sleeve 14 and the outer diameter of the inner core rod 11 at the corresponding position is less than 0.01mm, it is more difficult to assemble and the processing is difficult. When the difference between the inner diameter of the end of the outer sleeve 12 away from the indicator sleeve 14 and the outer diameter of the inner core rod 11 at the corresponding position is greater than 0.2mm, it is easy to cause a large gap. After the outer sleeve 12 and the inner core rod 11 are welded and fixed, it is not convenient to ensure that the outer sleeve 12 and the inner core rod 11 are coaxial, which affects the accuracy of the torsion angle marking result.

[0109] The inner diameter of the end of the outer sleeve 12 near the indicator sleeve 14 is 0.3mm, 0.32mm, 0.43mm, 0.5mm, 0.77mm, or 10mm larger than the outer diameter of the inner core rod 11 at the position where it is aligned. When the difference between the inner diameter of the end of the outer sleeve 12 near the indicator sleeve 14 and the outer diameter of the inner core rod 11 at the position where it is aligned is less than 0.3mm, it is easy to cause interference between components. When the difference between the inner diameter of the end of the outer sleeve 12 near the indicator sleeve 14 and the outer diameter of the inner core rod 11 at the position where it is aligned is greater than 10mm, it will cause the gap to be too large, resulting in an oversized device, which is not conducive to surgical operation. The outer sleeve 12 will also play a role of radial limit constraint on the inner core rod 11. If the difference is too large, it cannot play a role of radial limit constraint on the inner core rod 11, and the stability of the inner core rod 11 is poor.

[0110] Furthermore, the inner hole of the outer sleeve 12 includes a plurality of sections, the inner diameters of the plurality of sections gradually increase along the direction of the outer sleeve 12 approaching the indicator sleeve 14 , and the length of the section with the smallest inner diameter is 2 mm to 30 mm.

[0111] The outer sleeve 12 in the embodiment of the present invention is composed of multiple sections, each section has a different diameter, and the diameter of the section closer to the indicator sleeve 14 is larger, and the length of the section with the smallest inner diameter (i.e., the section farthest from the indicator sleeve 14) can be 2mm, 8mm, 12mm, 17.5mm, 22mm, 28mm, 29.3mm, or 30mm. When the length of the section with the smallest inner diameter is less than 2mm, it is easy to cause the outer sleeve 12 to shake and the fixation is unstable. When the length of the section with the smallest inner diameter is greater than 30mm, it is easy for the section to be too long, affecting the total length of the outer sleeve 12.

[0112] Optionally, the indicator sleeve 14 is located at the end of the outer sleeve 12 away from the driving part 13. By arranging the indicator sleeve 14 at the end away from the driving part 13, on the one hand, it can avoid contact with human tissue, and on the other hand, it is closer to the doctor's face, making it convenient for the doctor to observe the positions of the first identification part 122 and the second identification part 142.

[0113] like Fig.19 and Fig. 20 As shown, in some embodiments, the outer sleeve 12 has an indicator disk 121, a first identification portion 122 is disposed on the indicator disk 121, the indicator sleeve 14 has an indicator arm 141, a second identification portion 142 is disposed on the indicator arm 141, and the number of the first identification portions 122 is multiple, and the multiple first identification portions 122 are arranged on the indicator disk 121 at intervals along the circumference of the inner core rod 11.

[0114] The embodiment of the present invention provides an indicator plate 121 and an indicator arm 141, and controls the distance between the first identification portion 122 and the second identification portion 142 and the axis of the inner core rod 11, so that the relative positions of the first identification portion 122 and the second identification portion 142 in the circumferential direction of the inner core rod 11 can be proportionally enlarged, which is more convenient for observation and the doctor's perception and judgment of the torque size is more accurate.

[0115] The number of the first identification parts 122 may be 2, 3 or 5, and each first identification part 122 may correspond to a different torque magnitude, so as to better remind the doctor when the torque requirements are different at different surgical stages.

[0116] Furthermore, the outer sleeve 12 has a hollow hole group, which includes a plurality of hollow holes 17 arranged along the circumference of the outer sleeve 12, and the number of the hollow hole group is one, or a plurality of hollow holes arranged along the axial direction of the outer sleeve 12. The hollow hole 17 can be a circular hole, a bar hole, a polygonal hole, or an elliptical hole. The provision of a plurality of hollow holes 17 can not only reduce the weight of the outer sleeve 12, making it more convenient for doctors to operate during surgery, but also facilitate the cleaning of the screwdriver after surgery, avoiding the accumulation of liquid in the tool and the growth of bacteria.

[0117] Since the embodiment of the present invention also optimizes the design of the gap between the outer sleeve 12 and the inner core rod 11, the discharge of the accumulated fluid between the outer sleeve 12 and the inner core rod 11 can be better guaranteed.

[0118] like Fig.19 and Fig. 20 As shown, in some embodiments, the indicator disk 121 has two limit portions 123, and the two limit portions 123 are arranged on the indicator disk 121 at intervals along the circumference of the inner core rod 11. The indicator arm 141 and the plurality of first identification portions 122 are all located between the two limit portions 123. The limit portions 123 and the indicator arm 141 are arranged relatively to each other in the circumferential direction of the inner core rod 11, and are suitable for limiting the relative angular displacement of the indicator arm 141 and the outer sleeve 12.

[0119] It should be understood that the limiting portion 123 can be a limiting platform or a limiting pin, or a raised step surface on the indicator plate 121. The limiting portion 123 can be integrally formed with the indicator plate 121, or can be separately manufactured and then fixedly connected together. In the embodiment of the present invention, by providing two limiting portions 123, the maximum torsion angle of the indicator arm 141 and the indicator plate 121 can be limited, but the torque applied by the screwdriver to the surgical fastener will not be limited.

[0120] After a force couple is applied to the inner core rod 11, in order to make the two cross sections on the inner core rod 11 have a torsion angle, that is, the inner core rod 11 will undergo a certain deformation, thereby sacrificing a portion of the rigidity of the inner core rod 11. The embodiment of the present invention, through the setting of the limiting portion 123, can limit the further deformation of the inner core rod 11 after the indicating arm rod 141 and the limiting portion 123 abut against each other, thereby enhancing the rigidity of the inner core rod 11, thereby applying a greater torque to the inner core rod 11, ensuring that the surgical fasteners reach an ideal locking state, and can also provide a sufficiently large torque in the opposite direction when the fasteners are removed.

[0121] Optionally, the indicator plate 121 of the embodiment of the present invention is fan-shaped, and the angle e between the two side edges of the indicator plate 121 in the circumferential direction of the inner core rod 11 is 25 degrees to 90 degrees.

[0122] Specifically, the angle between the two sides of the indicator plate 121 on the circumference of the inner core rod 11 is 25 degrees, 33 degrees, 38 degrees, 45 degrees, 60 degrees, 77 degrees or 90 degrees. When the angle between the two sides of the indicator plate 121 on the circumference of the inner core rod 11 is less than 25 degrees, it is difficult to provide an effective torsion range, and it is not convenient to judge the torque by observing the torsion angle. When the angle between the two sides of the indicator plate 121 on the circumference of the inner core rod 11 is greater than 90 degrees, it exceeds the single rotation angle of the screwdriver during the surgical operation, which is poor in practicality, and the excessive torsion angle will affect the performance of the screwdriver, indicating that the inner core rod 11 has a large deformation and poor rigidity, and cannot play a locking and fixing effect.

[0123] Furthermore, the included angle f of the sector-shaped area between the two limiting portions 123 that enables the indicating arm 141 to move may be in a range of 26 degrees to 89 degrees.

[0124] In some embodiments, the surgical screwdriver 100 further includes a washer 19, which is located between the outer sleeve 12 and the indicator sleeve 14; specifically, the washer 19 is located between one end of the indicator plate 121 close to the inner core rod 11 and one end of the indicator arm 141 close to the inner core rod 11, so that when the outer sleeve 12 and the indicator sleeve 14 rotate relative to each other, direct friction between the two is avoided, thereby reducing friction loss. The washer 19 can be made of non-metallic materials.

[0125] In some embodiments, the torsional section coefficient Wc of the screwdriver body at the breaking groove is equal to the torsional section coefficient Wc of the driving part. 13 70% to 98%.

[0126] For example, the torsional section coefficient Wc of the screwdriver body at the breaking groove is equal to the torsional section coefficient Wc of the driving part. 13 70%, 75%, 77%, 86%, 90%, 95.6% or 98%.

[0127] It can be seen that the maximum shear stress τ on a certain cross section of the rod max The closer it is to (or exceeds) the allowable shear stress of the material, the more likely it is that damage will occur at that location.

[0128] Due to the maximum shear stress τ max It cannot be expressed intuitively and exists at the section where the maximum torque is located, that is, the dangerous point on the dangerous section, so the maximum shear stress τ max It can be quantified by the following formula:

[0129]

[0130] Where Ip is the polar moment of inertia of the cross section; r is the distance from the edge of the cross section to the centroid of the cross section; T is the torque; W p is the torsional section modulus of the cross section.

[0131] The embodiment of the present invention utilizes the polar moment of inertia Ip or the torsional section coefficient W at the cross section. p The torsional performance of the cross section is evaluated. The torsional section coefficient or polar moment of inertia of the fracture groove is set to 70%-98% of the torsional section coefficient or moment of inertia at the drive part. When the torque of the surgical screwdriver gradually increases to 70%-98% of the maximum torque that the drive part can withstand, the screwdriver is twisted off at the fracture groove. The cross section of the fracture groove is a regular circle, and the fracture here is smooth without broken debris.

[0132] Specifically, the cross section of the fracture groove is circular. From material mechanics, it is known that the polar moment of inertia I at the fracture groove is c Or the torsional section coefficient Wc is:

[0133]

[0134] Where C is the minimum diameter of the cross section at the fracture groove.

[0135] The torsional section coefficient and polar moment of inertia of the cross section of the driving part can be calculated by formula or further obtained through software analysis.

[0136] When the cross section of the driving part is a regular hexagon, such as Fig.21 As shown, then:

[0137] Moment of inertia of a regular hexagon I x and I y Satisfaction: I x =I y =0.5413*R 4 ;

[0138] The polar moment of inertia of a centrally symmetrical figure is equal to 2*moment of inertia, so the polar moment of inertia of a regular hexagon is I 13 :I13 =I x +I y ;

[0139] Regular hexagonal torsional section modulus W 13 satisfy:

[0140] Wherein, R is the radius of the circumscribed circle of the regular hexagon.

[0141] When the cross section of the driving part is a positive multi-petal shape, such as Fig. 22 As shown, the torsional section coefficient W of the positive multi-petal shape 13 Satisfies the following formula:

[0142]

[0143] Among them, D is the radius of the large circle of the regular multi-petal shape, Z is the number of petals of the regular multi-petal shape, b is the width of the petal part, and d is the diameter of the small circle in the regular multi-petal shape.

[0144] In the application, combined with the above formula, the torsional section coefficient W at the driving part is determined by the shape and size of the cross section of the driving part. 13 , the value range of the torsional section coefficient Wc at the fracture groove is 70% W 13 Up to 98%W 13 , and then the range of the minimum diameter C of the cross section at the fracture groove is obtained, and the value of C is determined.

[0145] When software analysis is used to obtain the torsional section coefficient and polar moment of inertia of the cross section of the driving part, UG software can be used for analysis. Taking the cross section of the driving part as a regular hexagon as an example, in UG NX10.0, enter the "Modeling" environment and click "Analysis" → "Section Inertia (N)" in the menu bar. In the pop-up "Section Inertia Analysis" dialog box, select "Existing Section" for type, select "Second Principal Moment of Inertia" for annotation, select "Principal Axis" for output, select "Solid" for section type, and then select the section curve to be analyzed to obtain the moment of inertia of the analyzed section, and then obtain the torsional section coefficient and polar moment of inertia of the section.

[0146] In summary, the driving part and the breaking groove on the inner core rod are subjected to the same torque when twisting the screwdriver, but the torsional section coefficients at the two locations are different. The smaller the torsional section coefficient, the greater the shear stress it bears. The embodiment of the present invention controls the diameter of the cross-sectional circle of the breaking groove to adjust the maximum shear stress it bears, and can break before the driving part. According to the above formula and software analysis of the section moment of inertia process, the size ratio of the torsional section coefficients at the two locations can be analyzed, calculated, and compared, so as to achieve the screwdriver effect and purpose in the embodiment of the present invention.

[0147] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0148] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0149] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0150] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0151] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0152] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A surgical screwdriver, characterized in that: include: A screwdriver body, one end of which has a driving portion, the driving portion being suitable for cooperating with a surgical fastener; A breaking groove is arranged along the circumference of the screwdriver body, and the maximum torque that the screwdriver body can withstand at the breaking groove is smaller than the maximum torque that the driving part can withstand.

2. The surgical screwdriver according to claim 1, characterized in that: The cross section of the breaking groove includes a first arc segment, and two sides of the first arc segment are connected to the outer wall surface of the screwdriver body; Alternatively, the cross section of the breaking groove includes a second arc segment and a straight line segment, and two sides of the second arc segment are connected to the outer wall surface of the screwdriver body through the straight line segment.

3. The surgical screwdriver according to claim 2, characterized in that: The radius of the first arc segment is 0.2 mm to 6 mm; Or, the radius of the second arc segment is 0.2 mm to 2 mm; Alternatively, the included angle between the two straight line segments on both sides of the second arc segment is 0 degree to 150 degrees.

4. The surgical screwdriver according to claim 1, characterized in that: The breaking groove is arranged close to the driving part; And / or, the breaking groove is a circular groove; And / or, the maximum torque that the screwdriver body can withstand at the breaking groove is 70% to 98% of the maximum torque that the driving part can withstand; And / or, the cross section of the driving portion is a polygon or a bisecting line; And / or, the end of the driving portion has a guide section, the cross-sectional size of the guide section gradually decreases from an end close to the driving portion to an end away from the driving portion, and the length of the guide section in the axial direction of the screwdriver body is 0.1 mm to 1 mm; And / or, the torsional section coefficient Wc of the screwdriver body at the breaking groove is the torsional section coefficient Wc of the driving part. 13 70% to 98%.

5. The surgical screwdriver according to claim 4, characterized in that: The cross section of the driving part is a regular hexagon, and the torsional section coefficient W of the driving part is 13 Satisfies the following formula: W 13 =1.0826*R 3 Wherein, R is the radius of the circumscribed circle of the regular hexagon; The torsional section coefficient Wc at the fracture groove satisfies the following formula: Wherein, C is the minimum diameter at the breaking groove; Or, the cross section of the driving part is a positive multi-petal shape, and the torsional section coefficient W of the driving part is 13 Satisfies the following formula: Wherein, D is the radius of the large circle of the regular multi-petal shape, Z is the number of petals of the regular multi-petal shape, b is the width of the petal portion, and d is the diameter of the small circle in the regular multi-petal shape; The torsional section coefficient Wc at the fracture groove satisfies the following formula: Wherein, C is the minimum diameter at the breaking groove.

6. The surgical screwdriver according to claim 1, characterized in that: The end of the screwdriver body away from the driving part has a handle, and the handle is fixedly connected to the screwdriver body; Alternatively, the end of the screwdriver body away from the driving portion has a connecting portion, and the connecting portion is suitable for quick disassembly and assembly with a connecting structure. The connecting portion includes an annular groove and a plurality of mating surfaces arranged along the circumference of the screwdriver body, and the annular groove is located on the side of the mating surface close to the driving portion, and the annular groove is suitable for limiting the connecting structure in the axial direction of the screwdriver body.

7. The surgical screwdriver according to any one of claims 1 to 6, characterized in that: The screwdriver body comprises an inner core rod, an outer sleeve and an indicator sleeve, the outer sleeve and the indicator sleeve are both fixedly sleeved on the inner core rod, the driving part and the breaking groove are both arranged on the inner core rod, the outer sleeve has a first identification part, and the indicator sleeve has a second identification part; After torque is applied to the inner core rod, the inner core rod will be deformed to cause a relative angular displacement between the indicator sleeve and the outer sleeve. The relative positions of the first identification portion and the second identification portion in the circumferential direction of the inner core rod are suitable for identifying the relative angular displacement between the indicator sleeve and the outer sleeve.

8. The surgical screwdriver according to claim 7, characterized in that: The gap between the inner core rod and one end of the outer sleeve away from the indicating sleeve is smaller than the gap between the inner core rod and one end of the outer sleeve close to the indicating sleeve.

9. The surgical screwdriver according to claim 8, characterized in that: The inner hole of the outer sleeve includes a plurality of sections, the inner diameters of the plurality of sections gradually increase along the direction in which the outer sleeve approaches the indicator sleeve, and the length of the section with the smallest inner diameter is 2 mm to 30 mm; And / or, the inner diameter of the end of the outer sleeve away from the indicator sleeve is 0.01mm to 0.2mm larger than the outer diameter of the inner core rod at the corresponding position, and the inner diameter of the end of the outer sleeve close to the indicator sleeve is 0.3mm to 10mm larger than the outer diameter of the inner core rod at the corresponding position; And / or, the indicator sleeve is located at an end of the outer sleeve away from the driving part; And / or, one end of the outer sleeve away from the indicating sleeve is fixedly connected to the inner core rod, and one end of the indicating sleeve away from the outer sleeve is fixedly connected to the inner core rod.

10. The surgical screwdriver according to claim 7, characterized in that: The outer sleeve has an indicator disk, the first identification portion is arranged on the indicator disk, the indicator sleeve has an indicator arm rod, the second identification portion is arranged on the indicator arm rod, there are multiple first identification portions, and the multiple first identification portions are arranged on the indicator disk at intervals along the circumference of the inner core rod.

11. The surgical screwdriver according to claim 10, characterized in that: The indicator plate has two limiting parts, which are arranged on the indicator plate at intervals along the circumference of the inner core rod, the indicator arm and the plurality of first identification parts are located between the two limiting parts, and the limiting parts and the indicator arm are arranged opposite to each other in the circumference of the inner core rod, and are suitable for limiting the relative angular displacement of the indicator arm and the outer sleeve; And / or, the indicator plate is fan-shaped, and the angle between the two side edges of the indicator plate in the circumferential direction of the inner core rod is 25 degrees to 90 degrees; And / or, further comprising a gasket, wherein the gasket is located between the outer sleeve and the indicator sleeve; And / or, the outer sleeve has a hollow hole group, the hollow hole group includes a plurality of hollow holes arranged along the circumference of the outer sleeve, and the number of the hollow hole group is one, or a plurality of hollow holes arranged along the axial direction of the outer sleeve.

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