A detachable inner core assembly and a surgical instrument using the same

Abstract

An easily detachable inner core assembly and surgical instrument using the same, comprising an inner rod assembly and an outer tube assembly, the outer tube assembly comprising a base and a hollow outer tube. The inner rod assembly comprises a first jaw, a second jaw, a first connecting rod, a second connecting rod, a main pin, a retainer ring and a driving rod. The first jaw comprises a first jaw tail, and the second jaw comprises a second jaw tail. The main pin comprises a pin head and a pin flange. The first jaw tail and the second jaw tail are stacked together, and the retainer ring is fixed with the main pin or the second jaw tail, thereby fixing the first and second jaw tails between the pin flange and the retainer ring to form a first rotating pair that can rotate around the main pin. The first jaw tail and the first connecting rod match to form a second rotating pair, and the second jaw tail and the second connecting rod match to form a third rotating pair. The first connecting rod and the driving rod match to form a fourth rotating pair, and the second connecting rod and the driving rod match to form a fifth rotating pair. The inner rod assembly is installed in the outer tube assembly, wherein the main pin shaft matches with the base to form a quick detachable structure.

Description

TECHNICAL FIELD

[0001] The present application relates to minimally invasive surgical instruments, and in particular to a detachable inner core assembly and surgical instruments using the same. BACKGROUND

[0002] Endoscopic minimally invasive surgery uses elongated endoscopic hand-held instruments to access the patient's body through natural orifices or constructed puncture channels to perform tissue grasping, cutting, separating, coagulation, suturing and closure operations. Compared with traditional open surgery, it has the advantages of reducing trauma, alleviating pain and accelerating recovery. So far, reusable endoscopic hand-held instruments (hereinafter referred to as reusable instruments) have dominated the market, and disposable endoscopic hand-held instruments (hereinafter referred to as disposable instruments) have relatively few clinical applications. Studies have shown that reusable instruments have problems of unreliable and uncontrollable cleaning, distribution and use, and so far there is no reliable solution. SUMMARY

[0003] Therefore, in order to solve the problems of the prior art, a detachable instrument is provided.

[0004] In one aspect of the present application, a detachable inner core assembly is provided, which comprises an inner rod assembly and an outer tube assembly. The outer tube assembly comprises a base and a hollow outer tube. The inner rod assembly comprises a first jaw, a second jaw, a first connecting rod, a second connecting rod, a main pin, a retainer and a driving rod. The proximal end of the first jaw comprises a first jaw tail and a first base hole transversely penetrating through it; the proximal end of the second jaw comprises a second jaw tail and a second base hole transversely penetrating through it. The main pin comprises a pin head and a pin flange, the first jaw tail and the second jaw tail are stacked together, the main pin passes through the first base hole and the second base hole, and the retainer is fixed with the main pin or the second jaw tail, thereby fixing the first and second jaw tails between the pin flange and the retainer to form a first rotating pair that can rotate around the main pin. The first jaw tail and the first connecting rod match to form a second rotating pair, the second jaw tail and the second connecting rod match to form a third rotating pair, the first connecting rod and the driving rod match to form a fourth rotating pair, and the second connecting rod and the driving rod match to form a fifth rotating pair. Moving the driving rod, the first, second, third, fourth and fifth rotating pairs can rotate simultaneously. The inner rod assembly is installed in the outer tube assembly, wherein the main pin shaft matches with the base to form a quick detachable structure.

[0005] In one aspect, the main pin comprises a first pin head, a second pin head and a pin flange arranged therebetween, the second pin head comprises a pin ring groove, and the retainer comprises a retainer hole defined by a ring-shaped piece, the shape and size of which match the pin ring groove. The first jaw tail and the second jaw tail are stacked together, the second pin head passes through the first base hole and the second base hole, and the retainer is fixed in the pin ring groove, thereby fixing the first and second jaw tails together and forming a first rotating pair that can rotate around the main pin.

[0006] In another aspect, the retaining ring further comprises a retaining ring opening, and the annular tab of the retaining ring is welded to the first jaw tail or the second jaw tail.

[0007] In another aspect, the first link comprises a first link head and a first link tail with a first link body extending therebetween, the first link head comprises a first link shaft extending transversely outwardly, and the first link tail comprises a first link hole extending transversely therethrough. The second link comprises a second link head and a second link tail with a second link body extending therebetween, the second link head comprises a second link shaft extending transversely outwardly, and the second link tail comprises a second link hole extending transversely therethrough. The proximal end of the first jaw tail comprises a first tail hole, and the first tail hole is fixedly attached to the first link shaft to form a second rotational pair. The proximal end of the second jaw tail comprises a second tail hole, and the second tail hole is fixedly attached to the second link shaft to form a third rotational pair.

[0008] In another aspect, the first link shaft end face comprises a first blind hole defined by a first shaft wall, and the first shaft wall is deformed outwardly to form a first crimp after the first link shaft penetrates the first tail hole. The second link shaft end face comprises a second blind hole defined by a second shaft wall, and the second shaft wall is deformed outwardly to form a second crimp after the second link shaft penetrates the second tail hole. The second crimp limits separation of the third rotational pair.

[0009] In another aspect, the drive rod comprises a drive head, and the drive head comprises a first drive shaft and a second drive shaft extending outwardly. The first drive shaft end face comprises a third shaft wall, and the second drive shaft end face comprises a fourth shaft wall. The third shaft wall is deformed outwardly to form a third crimp after the first drive shaft penetrates the first link hole to limit separation of a fourth rotational pair. The fourth shaft wall is deformed outwardly to form a fourth crimp after the second drive shaft penetrates the second link hole to limit separation of a fifth rotational pair.

[0010] In another aspect, the base comprises a first longitudinal reference plane and a second longitudinal reference plane perpendicular to each other and intersecting the main axis, the base further comprises a base tail and a first main arm and a second main arm extending to a distal end, the first and second main arms are disposed on two sides of the first longitudinal reference plane and define a U-shaped slot. The base further comprises a first special-shaped slot and a second special-shaped slot, the first special-shaped slot extends along the second longitudinal reference plane from the distal end of the first main arm to the proximal end and divides it into a first elastic arm and a second elastic arm; the second special-shaped slot extends along the second longitudinal reference plane from the distal end of the second main arm to the proximal end and divides it into a third elastic arm and a fourth elastic arm. One end of the pin head of the main pin is clamped in the first special-shaped slot between the first elastic arm and the second elastic arm to form a first engagement pair, the other end of the pin head of the main pin is clamped in the second special-shaped slot between the second elastic arm and the third elastic arm to form a second engagement pair. Moving the drive rod from the distal end to the proximal end can make the one end of the pin head of the main pin slide into the first special-shaped slot to form the first engagement pair, and at the same time make the other end of the pin head of the main pin slide into the second special-shaped slot to form the second engagement pair. Moving the drive rod from the proximal end to the distal end can make the one end of the pin head of the main pin slide out of the first special-shaped slot to separate the first engagement pair, and at the same time make the other end of the pin head of the main pin slide out of the second special-shaped slot to separate the second engagement pair.

[0011] In another aspect, the first special-shaped slot comprises a distal first guide port, a first cylindrical surface and a first cutting groove, the maximum opening width of the first guide port is H11, the diameter of the first cylindrical surface is D11, the first guide port and the first cylindrical surface intersect to form a first engagement opening with an opening width of H12, wherein H11≥D11>H12. The second special-shaped slot comprises a distal second guide port, a second cylindrical surface and a second cutting groove, the maximum opening width of the second guide port is H21, the diameter of the second cylindrical surface is D21, the second guide port and the second cylindrical surface intersect to form a second engagement opening with an opening width of H22, wherein H21≥D21>H22. The one end of the pin head of the main pin is embedded in the first cylindrical surface to form the first engagement pair, and the other end of the pin head of the main pin is embedded in the second cylindrical surface to form the second engagement pair.

[0012] In another aspect of the application, a surgical instrument for minimally invasive surgery, the instrument comprises the inner core assembly as claimed in any one of claims 1-9, and further comprises a handle assembly matched therewith; the handle assembly comprises a rotating wheel assembly, a button assembly, a handle rotating shaft and a first handle and a second handle rotating therearound; the outer tube assembly of the inner core assembly is matched with the rotating wheel assembly and the button assembly; the driving rod comprises a driving head, a driving tail and a driving rod extending therebetween, the driving tail is connected with the second handle, the first handle and the second handle rotate around the handle rotating shaft to move the driving tail, and further move the driving head, and further drive the first, second, third, fourth and fifth rotating pairs to rotate, and further drive the first and second jaws to rotate and open or close around the first rotating pair.

[0013] In another aspect of the application, a surgical instrument for minimally invasive surgery, the instrument comprises the inner core assembly as claimed in any one of claims 1-9, and further comprises a handle assembly matched therewith; the handle assembly comprises a rotating wheel assembly, a button assembly, a handle rotating shaft and a first handle and a second handle rotating therearound; the outer tube assembly of the inner core assembly is matched with the rotating wheel assembly and the button assembly; the driving rod comprises a driving head, a driving tail and a driving rod extending therebetween, the driving tail is connected with the second handle, the first handle and the second handle rotate around the handle rotating shaft to move the driving tail, and further move the driving head, and further drive the first, second, third, fourth and fifth rotating pairs to rotate, and further drive the first and second jaws to rotate and open or close around the first rotating pair. BRIEF DESCRIPTION OF DRAWINGS

[0014] For a more complete understanding of the application, reference is made to the following detailed description taken in conjunction with the accompanying drawings in which:

[0015] Figure 1 is a 3D schematic view of the instrument 1;

[0016] Figure 2 is a 3D schematic view of the inner core assembly 3;

[0017] Figure 3 is an exploded schematic view of the inner core assembly 3;

[0018] Figure 4 is a sectional view of the outer tube assembly 5 along its axis;

[0019] Figure 5 is a projection schematic view of the base 51 in its second longitudinal reference plane 502;

[0020] Figure 6 is a schematic view of the projection of the base 51 in its first longitudinal reference plane 501;

[0021] Figure 7 is a 3D schematic view of the base 51;

[0022] Figure 8 is an exploded schematic view of the inner rod assembly 4;

[0023] Figure 9 is a lateral schematic view of the inner rod assembly 4;

[0024] Figure 10 is a 10-10 sectional view of Figure 9 ;

[0025] Figure 11 is an 11-11 sectional view of Figure 9 ;

[0026] Figure 12 is a partial projection view of the distal end of the inner core assembly 3;

[0027] Figure 13 is a 13-13 sectional view of Figure 12 ;

[0028] Figure 14 is a partial sectional view of the inner core assembly cooperating with the handle assembly;

[0029] Figure 15 is a partial projection view of the distal end of a further improved inner core;

[0030] Figure 16 is a 16-16 sectional view of Figure 15 ;

[0031] In all the views, the same reference numbers indicate equivalent parts or components. DETAILED DESCRIPTION

[0032] Embodiments of the present application are disclosed herein, but it is understood that the disclosed embodiments are merely examples of the present application and can be practiced in various ways. Therefore, the disclosure is not to be interpreted as being limited only to the disclosed embodiments, but rather is to be interpreted broadly enough to encompass all techniques, alternatives and modifications coming within the scope of the present application. Accordingly, the claims are to be interpreted broadly enough to encompass all techniques, alternatives and modifications coming within the scope of the present application.

[0033] Reference is made to Figure 1For convenience of description, the side close to the operator is defined as proximal end, and the side away from the operator is defined as distal end. During a laparoscopic surgery, a trocar assembly (not shown) is usually used to establish a surgical channel for instruments to access the patient's body cavity. Various minimally invasive instruments, such as instrument 1, can be inserted into the body cavity through the channel formed by the trocar assembly. One or more trocar assemblies can be used simultaneously during a surgery, and instrument 1 can also be configured with one or more channels for simultaneous operation as required by the surgery.

[0034] Figures 1-4 A typical laparoscopic hand-held instrument 1 is depicted, which comprises a handle assembly 2 and an inner core assembly 3. The inner core assembly 3 comprises an inner rod assembly 4 and an outer tube assembly 5.

[0035] As Figures 3-7 , the base 51 comprises a first longitudinal reference plane 501 and a second longitudinal reference plane 502 perpendicular to each other, and a main intersection axis 503. The base 510 further comprises a base tail 505, and a first main arm 507 and a second main arm 508 extending to the distal end, which are arranged on both sides of the first longitudinal reference plane and define a U-shaped slot 506; a base shaft hole 504 extends through the base tail 505 in the axial direction and is connected to the U-shaped slot 506; the hole axis is substantially coincident with the main intersection axis.

[0036] Referring now to Figures 5-7 , the base 51 further comprises a first special-shaped slot 510 and a second special-shaped slot 520. The first special-shaped slot 510 extends along the second longitudinal reference plane 502 from the distal end of the first main arm to the proximal end and divides it into a first elastic arm 515 and a second elastic arm 517. The second special-shaped slot 520 extends along the second longitudinal reference plane 502 from the distal end of the second main arm to the proximal end and divides it into a third elastic arm 525 and a fourth elastic arm 527. The first special-shaped slot 510 comprises a distal first guide port 511, a first cylindrical surface 512, and a first cut-off slot 513. The maximum opening width of the first guide port is H11, the diameter of the first cylindrical surface 512 is D11, and the first guide port 511 and the first cylindrical surface 512 intersect to form a first bite 516 with an opening width of H12. In a preferred embodiment, H11≥D11>H12. The first cut-off slot cuts off the first cylindrical surface 512 and extends towards the proximal end of the first main arm.

[0037] Similarly, as Figures 5-7The second heterotypic slot 520 includes a distal second guide port 521, a second cylindrical surface 522 and a second severing slot 523. The second guide port has a maximum opening width of H21, the second cylindrical surface 522 has a diameter of D21, and the second guide port 521 and the second cylindrical surface 522 intersect to form a second bite port 526 having an opening width of H22. In a preferred embodiment, H21 > D21 > H22. The second severing slot severs the second cylindrical surface 522 and extends proximally toward the second main arm. (H21, D21 and H22 are not labeled in the figures, but can be understood by reference to Figure 6 The first cylindrical surface 512 includes a first transverse axis 514 and the second cylindrical surface 522 includes a second transverse axis 524, which are substantially coincident and perpendicular to the first longitudinal reference plane.

[0038] Reference is now made to Figures 3-4 The hollow outer tube 55 includes an outer tube head 550 and an outer tube tail 570 and an outer tube body 560 extending therebetween, an axial through hole 551 extending axially through the outer tube head and the outer tube tail. The outer tube tail further includes an outer tube ring slot 571 and an adapter 575. The base 51 and the hollow outer tube 55 can be fixed together by welding, riveting or gluing processes or can be machined from a single piece of metal material. The outer tube assembly 5 can further include an insulating tube 59 mounted on its surface.

[0039] Figure 8 An exploded view of the inner rod assembly 4 is depicted. The inner rod assembly 4 includes a first jaw 41, a second jaw 42, a first link 43, a second link 44, a king pin 45, a retaining ring 46 and a drive rod 47.

[0040] Reference is now made to the drawings, which show preferred embodiments of the application. Figure 8 The proximal end of the first jaw 41 includes a first jaw tail 413 having a thickness Hj1 defined by a first outer side surface 411 and a first inner side surface 412. The proximal end of the first jaw tail 413 includes a transversely extending first tail hole 414 and the distal end of the first jaw tail 413 includes a transversely extending first base hole 415. A first jaw wrist 416 is integral with the first jaw tail 413 and extends distally to form a first jaw head 419. The proximal end of the second jaw 42 includes a second jaw tail 423 having a thickness Hj2 defined by a second outer side surface 421 and a second inner side surface 422. The proximal end of the second jaw tail 423 includes a transversely extending second tail hole 424 and the distal end of the second jaw tail 423 includes a transversely extending second base hole 425. A second jaw wrist 426 is integral with the second jaw tail 423 and extends distally to form a second jaw head 429.

[0041] Reference is now made to the drawings, which show preferred embodiments of the application. Figure 8The first link 43 includes a first link head 431 and a first link tail 433 and a first link body 432 extending therebetween; the first link head 431 includes a first link shaft 435 extending laterally outwardly therefrom, and the first link tail 433 includes a first link hole 437 extending laterally therethrough. The second link 44 includes a second link head 441 and a second link tail 443 and a second link body 442 extending therebetween; the second link head 441 includes a second link shaft 445 extending laterally outwardly therefrom, and the second link tail 443 includes a second link hole 447 extending laterally therethrough. The kingpin 45 includes a first pin head 451, a second pin head 455 and a pin flange 453 disposed therebetween, the pin flange 453 having a diameter greater than the first pin head (second pin head). The retainer 46 includes a retainer hole 465 defined by an annular tab 461.

[0042] The present application will now be described in greater detail Figure 3 and Figure 8 The drive rod 47 includes a drive head 471, a drive tail 479 and a drive stem 477 extending therebetween. The drive head 471 includes a first drive shaft 473 and a second drive shaft 475 extending laterally outwardly therefrom. The drive tail 479 includes a drive rod annular groove 478.

[0043] Figure 3 , Figures 8-11 The structural components and assembly relationship of the inner link assembly 4 are depicted in greater detail. The first jaw tail 413 and the second jaw tail 423 are stacked on each other; the second pin head 455 passes through the first base hole 415 and the second base hole 425; the retainer 46 is secured in the vicinity of the end of the second pin head 455, securing the first and second jaw tails together and forming a first revolute pair rotatable about the kingpin 45. The first link shaft 435 penetrates the first tail hole 414, securing the first link head 431 and the first jaw tail 413 together and forming a second revolute pair rotatable about the first link shaft 435. The second link shaft 445 penetrates the second tail hole 424, securing the second link head 441 and the second jaw tail 423 together and forming a third revolute pair rotatable about the second link shaft 445. The first drive shaft 473 penetrates the first link hole 437, securing the first link tail 433 and the drive head 471 together and forming a fourth revolute pair rotatable about the first drive shaft 473. The second drive shaft 475 penetrates the second link hole 447, securing the second link tail 443 and the drive head 471 together and forming a fifth revolute pair rotatable about the second drive shaft 475. Pulling the drive rod 47, the first, second, third, fourth and fifth revolute pairs rotate simultaneously.

[0044] Figure 2 , Figures 12-13The assembly relationship of the inner core assembly 3 is described in more detail. The driving rod 47 is assembled into the axial through hole 551 of the outer tube assembly; the first and second jaw tails, the first and second connecting rods are assembled into the U-shaped slot 506; the first pin head 451 is embedded into the second cylindrical surface 522 to form the first jaw pair; the second pin head 455 is embedded into the first cylindrical surface 512 to form the second jaw pair. The first and second jaw pairs support and fix the two ends of the kingpin shaft, when the driving head 471 moves, the first and second connecting rods move and rotate, driving the first and second jaw tails to rotate, thereby realizing the closing or opening of the first and second jaw heads.

[0045] It is understood in conjunction with Figure 1 , Figure 2 , Figure 4 and Figure 14 . The handle assembly 2 comprises a first handle 92 and a second handle 93 connected by a handle rotation shaft 91, and the first handle and the second handle can rotate around the handle rotation shaft. The rotating wheel assembly 95 comprises a rotating wheel 951, an outer sleeve 953 and an inner sleeve 955, the outer sleeve 953 is integrated with the rotating wheel 951, the inner sleeve 955 is integrated with the first handle 92, and the outer sleeve 953 and the inner sleeve 955 constitute a rotating mechanism to enable the rotating wheel 951 to rotate relative to the first handle. The button assembly 97 is installed in the button installation compartment 98 of the first handle 92. The button assembly 97 comprises a lock piece 972, one end of which is connected with an elastic element 971 and the other end of which is connected with a button 974, and a fastener 973 restricts the lock piece 972 in the installation compartment 98, and the elastic element 971 drives the lock piece 972 to move laterally in the installation compartment 98 to a locking position. The handheld instrument 1 comprises the handle assembly 2 and the inner core assembly 3. Wherein the driving tail 479 matches the second handle 93, the elastic element 971 drives the lock piece 972 to move laterally in the installation compartment 98 to the locking position and matches the limiting slot 48, and the connecting head 575 matches the rotating wheel 951 and transmits the rotating torque from the rotating wheel to the inner core assembly. The first handle and the second handle rotate around the handle rotation shaft, thereby pushing the driving tail 479 to move in the axial direction, and then pushing the driving head to move in the axial direction, and then driving the first and second connecting rods to move and rotate, driving the first and second jaw tails to rotate, thereby realizing the closing or opening of the first and second jaw heads. Pressing the button 97 compresses the elastic element 971 to make the lock piece 972 move laterally away from the locking position, so that the limiting slot 48 is separated from the lock piece 972, thereby separating the inner core assembly 3 and the handle assembly 2.

[0046] It is understood in conjunction with Figures 1-3 and Figures 9-14 , in a preferred design, the inner core assembly 3 comprises three states of working state, critical state and separation state, and the driving head 70 comprises working displacement Lw1 and critical displacement Le1 (displacement measurement method: the shortest distance between the first driving shaft axis and the kingpin axis), wherein Lw1>Le1.

[0047] Working state: when the driving head is in working displacement Lw1, the first pin head keeps in contact with the second cylindrical surface, i.e. the first occlusion pair is in occlusion state; the second pin head keeps in contact with the first cylindrical surface, i.e. the second occlusion pair is in occlusion state. In working state, operating the first handle and the second handle can drive the first and second jaw heads to close or open in the range of 0~A1 angle. Usually, A1 is designed as 65~85°.

[0048] Critical state: when the driving head is in critical displacement Le1, continue to operate the first handle and the second handle to move away from each other, so that the driving head moves in the direction of reducing the distance between the first driving shaft axis and the main pin axis, at this time the opening angle of the first and second jaw heads reaches the maximum limit angle A1, and Le1 no longer decreases; continue to operate the first handle and the second handle to move away from each other, at this time the driving head pushes the first and second jaw tails to move towards the distal end, and further pushes the first and second pin heads to move towards the distal end and pushes the first and second occlusions to open.

[0049] Separation state: in the critical state, continue to operate the first handle and the second handle to move away from each other; push the first and second pin heads to move towards the distal end; completely expand the first and second occlusions and slip into the first and second guide openings; i.e. the first and second occlusion pairs are in invalid separation state; so as to realize the separation of the inner rod assembly and the outer tube assembly.

[0050] Those skilled in the art should understand that according to the actual needs of the surgical instrument, the size and shape of the first and second connecting rods, the first and second jaw tails and the driving head can be adjusted to adjust the specific value of Le1. Additional limiting mechanism can be added to limit the displacement of the driving head to Lw1>Le1 during use, to prevent it from coming off during use.

[0051] In another scheme, the inner core assembly 3 has no obvious critical state, i.e. the operating force cannot push the first and second pin heads to completely expand and the first and second occlusions. Those skilled in the art should understand that auxiliary tools can be used to push or pull the inner rod assembly and the outer tube assembly respectively to make them move away from each other, so as to push the first and second pin heads to move towards the distal end; completely expand the first and second occlusions and slip into the first and second guide openings; i.e. the first and second occlusion pairs are in invalid separation state; so as to realize the separation of the inner rod assembly and the outer tube assembly.

[0052] The reassembly of the inner rod assembly and the outer tube assembly is the reverse operation of the disassembly: the first handle and the second handle are folded towards each other, the first and second pin heads are pulled to move towards the proximal end through the first and second guide ports; the first and second jaws are fully expanded and clamped into the first and second cylindrical surfaces; that is, the first pin head is in contact with the second cylindrical surface, and the first jaw pair is in the clamped state; the second pin head is in contact with the first cylindrical surface, and the second jaw pair is in the clamped state; thereby achieving the reassembly of the inner rod assembly and the outer tube assembly. Similarly, the reassembly can also be achieved by using auxiliary tools.

[0053] Reusable endoscopic hand-held instruments are usually disassembled into two parts of a handle and an inner core assembly, cleaned, reassembled and sterilized before use. The sterilization methods are usually high-temperature moist heat sterilization or low-temperature plasma sterilization. However, no matter which sterilization method is used, the used instrument must be thoroughly cleaned first, then sterilized according to the corresponding sterilization procedure, and then used for surgery again. During surgery, the head of the instrument needs to operate on the patient's body, and the moving joints of the head of the instrument are prone to residual tissue residues, which are difficult to clean. In order to solve this problem, the prior art discloses a scheme of disassembling the inner core assembly into two parts or three parts. However, so far, the first jaw, the second jaw and the base of the head of the reusable endoscopic hand-held instruments disclosed in the prior art and commercialized are usually not disassembled. This causes the moving joints between the first jaw, the second jaw and the base to be prone to residual pathological tissues or bacteria and viruses, which are extremely difficult to clean, making the sterilization process unreliable and posing a risk of cross infection. When the inner rod assembly and the outer tube assembly of the aforementioned inner core assembly 3 are disassembled, the base and the first and second jaws can be separated, effectively solving the problem that the residual tissues in the base are extremely difficult to clean. This disassembling mechanism makes the moving pairs of the head of the inner rod assembly more robust, meeting the disassembling requirement while effectively increasing the strength and accuracy of the moving pairs.

[0054] The fixing method between the retaining ring 46 and the second pin head 455 is various, including but not limited to interference fit, welding, bonding, etc. Laser welding is preferred. Considering that the main load borne by the main pin 45 is shear load, and the load borne by the retaining ring 46 is relatively small, an improved main pin 45a (as shown in Figures 15-16 ) is provided, which comprises a first pin head 451, a second pin head 455a and a pin flange 453 arranged therebetween; the second pin head 455a comprises a pin ring groove 457. The retaining ring 46a comprises a retaining ring hole 465a defined by a ring-shaped piece 461a, which is matched in shape and size with the pin ring groove 457; in an optional scheme, the retaining ring 46a further comprises a retaining ring opening 463a to facilitate assembly.

[0055] Reference Figures 15-16, the first jaw tail 413 and the second jaw tail 423 are stacked on each other; the second pin head 455a penetrates the first base hole 415 and the second base hole 425; the retaining ring 46a is fixed in the pin ring groove 457, fixing the first and second jaw tails together and constituting a first rotating pair rotatable around the main pin 45a. In one solution, the retaining ring opening 463a can be welded to enhance the firmness of the fixation. In another solution, the annular sheet 461a can be welded to the first jaw tail 413. When the welding solution is adopted, the retaining ring 46a can be divided into two or more pieces to facilitate assembly. Welding the retaining ring itself or the retaining ring and the jaw tail without welding the main pin can reduce the impact of welding on the main pin and prevent shear fracture.

[0056] Reference is now made to Figures 9-11 , where reference is made primarily to Figure 11 In one preferred solution, the first connecting rod shaft 435 end face comprises a first blind hole 439 defined by a first shaft wall 436; after the first connecting rod shaft 435 penetrates the first tail hole 414 during assembly, a tool is used to force the first shaft wall 436 to deform outwardly to form a first crimp (not shown in the figure); thereby fixing the first connecting rod head 431 and the first jaw tail 413 together and constituting a second rotating pair rotatable around the first connecting rod shaft 435. The second connecting rod shaft 445 end face comprises a second blind hole 449 defined by a second shaft wall 446; after the second connecting rod shaft 445 penetrates the second tail hole 424 during assembly, a tool is used to force the second shaft wall 446 to deform outwardly to form a second crimp (not shown in the figure); thereby fixing the second connecting rod head 441 and the second jaw tail 423 together and constituting a third rotating pair rotatable around the second connecting rod shaft 445.

[0057] Reference is made to Figure 10 Similarly, the first drive shaft 473 end face comprises a third shaft wall 472; after the first drive shaft 473 penetrates the first connecting rod hole 437 during assembly, a tool is used to force the third shaft wall 472 to deform outwardly to form a third crimp (not shown in the figure); thereby fixing the first connecting rod tail 433 and the drive head 471 together and constituting a fourth rotating pair rotatable around the first drive shaft 473. The second drive shaft 475 end face comprises a fourth shaft wall 474; after the second drive shaft 475 penetrates the second connecting rod hole 447 during assembly, a tool is used to force the fourth shaft wall 474 to deform outwardly to form a fourth crimp (not shown in the figure); thereby fixing the second connecting rod tail 443 and the drive head 471 together and constituting a fifth rotating pair rotatable around the second drive shaft 475.

[0058] The skilled in the art should understand that the first, second, third, fourth edge structures disclosed above can also form a small edge on the end of the shaft without the first (second, third, fourth) shaft wall, which can still prevent the second (third, fourth, fifth) rotating pair from disengaging. The driving head 471, the first driving shaft 473 and the second driving shaft 475 disclosed above are integrated, but the driving head can also be provided with a driving head through hole, and an additional shaft can be riveted in the driving head through hole to form the first driving shaft and the second driving shaft. The driving head can also be clamped between the first and second connecting rods, and an additional shaft can be passed through the first and second connecting rod holes and the driving head through hole, and then riveted to form the fourth and fifth rotating pairs. More similar alternatives are also easy to think of, and will not be described here.

[0059] US5489290, US5947996, US6340365, US7931667, US8551077, US8926599 disclose various quick connection and disconnection mechanisms between the inner core assembly and the reusable handle, which can be slightly modified and used in the connection between the inner core assembly and the reusable handle of the present application. So far, many connection methods between the inner core assembly and the handle of the minimally invasive surgical instrument have been disclosed in the field of minimally invasive surgical instruments, which can be slightly modified and used in the connection between the inner core assembly and the handle of the present application, and will not be listed here. The skilled in the art should understand that the first, second, third, fourth and fifth do not have a strict order, and are only for the convenience of understanding for the sake of simplicity and accuracy of description.

Claims

1. A detachable inner core assembly comprising an inner rod assembly and an outer tube assembly, said outer tube assembly comprising a base and a hollow outer tube, characterized in that: 1) said inner rod assembly comprises a first jaw, a second jaw, a first connecting rod, a second connecting rod, a main pin, a retainer and a driving rod; 2) a proximal end of said first jaw comprises a first jaw tail and a first base hole transversely passing through it; a proximal end of said second jaw comprises a second jaw tail and a second base hole transversely passing through it; 3) said main pin comprises a pin head and a pin flange, said first jaw tail and said second jaw tail are stacked together, said main pin passes through said first base hole and said second base hole, said retainer is fixed with said main pin or said second jaw tail, thereby fixing said first jaw tail and said second jaw tail together between said pin flange and said retainer to form a first rotating pair rotatable around said main pin; 4) said first jaw tail and said first connecting rod match to form a second rotating pair, said second jaw tail and said second connecting rod match to form a third rotating pair; 5) said first connecting rod and said driving rod match to form a fourth rotating pair, said second connecting rod and said driving rod match to form a fifth rotating pair; 6) moving said driving rod, said first, second, third, fourth and fifth rotating pairs can rotate simultaneously; 7) said inner rod assembly is installed in said outer tube assembly, wherein said main pin matches with said base to form a quick detachable structure; 8) said base comprises a first longitudinal reference plane and a second longitudinal reference plane perpendicular to each other and an intersecting main axis, said base further comprises a base tail and a first main arm and a second main arm extending to a distal end, said first main arm and said second main arm are disposed on two sides of said first longitudinal reference plane and define a U-shaped slot; 9) said base further comprises a first profiled slot and a second profiled slot, said first profiled slot extends along said second longitudinal reference plane from a distal end of said first main arm to a proximal end and divides said first main arm into a first elastic arm and a second elastic arm; said second profiled slot extends along said second longitudinal reference plane from a distal end of said second main arm to a proximal end and divides said second main arm into a third elastic arm and a fourth elastic arm; 10) one end of said main pin head is clamped in said first profiled slot between said first elastic arm and said second elastic arm to form a first clamping pair, the other end of said main pin head is clamped in said second profiled slot between said second elastic arm and said third elastic arm to form a second clamping pair; 11) moving said driving rod from a distal end to a proximal end, one end of said main pin head slides into said first profiled slot to form said first clamping pair, and the other end of said main pin head slides into said second profiled slot to form said second clamping pair; 12) moving said driving rod from a proximal end to a distal end, one end of said main pin head slides out of said first profiled slot to separate said first clamping pair, and the other end of said main pin head slides out of said second profiled slot to separate said second clamping pair.

2. The inner core assembly of claim 1, characterized in that: 1) said main pin comprises a first pin head, a second pin head and a pin flange disposed therebetween, said second pin head comprises a pin ring groove, and said retainer comprises a retainer hole with a shape and size matched with said pin ring groove; 2) said first jaw tail and said second jaw tail are stacked together, said second pin head passes through said first base hole and said second base hole, and said retainer is fixed in said pin ring groove to fix said first jaw tail and said second jaw tail together and form a first rotating pair rotatable around said main pin.

3. The inner core assembly of claim 2, wherein: The retaining ring further comprises a retaining ring opening, and the annular piece of the retaining ring is welded to the first jaw tail or the second jaw tail.

4. The inner core assembly of claim 1, wherein: 1) the first link comprises a first link head and a first link tail with a first link body extending therebetween, the first link head comprises a first link shaft extending transversely outward, and the first link tail comprises a first link hole extending transversely therethrough; 2) the second link comprises a second link head and a second link tail with a second link body extending therebetween, the second link head comprises a second link shaft extending transversely outward, and the second link tail comprises a second link hole extending transversely therethrough; 3) the proximal end of the first jaw tail comprises a first tail hole, and the first tail hole is fixed with the first link shaft to form a second rotational pair; the proximal end of the second jaw tail comprises a second tail hole, and the second tail hole is fixed with the second link shaft to form a third rotational pair.

5. The inner core assembly of claim 4, wherein: 1) the first link shaft end face comprises a first blind hole defined by a first shaft wall, and after the first link shaft penetrates the first tail hole, the first shaft wall is deformed outward to form a first crimping edge, and the first crimping edge limits the separation of the second rotational pair; 2) the second link shaft end face comprises a second blind hole defined by a second shaft wall, and after the second link shaft penetrates the second tail hole, the second shaft wall is deformed outward to form a second crimping edge, and the second crimping edge limits the separation of the third rotational pair.

6. The inner core assembly of claim 4, wherein: 1) the drive rod comprises a drive head, and the drive head comprises a first drive shaft and a second drive shaft extending outward; the first drive shaft end face comprises a third shaft wall, and the second drive shaft end face comprises a fourth shaft wall; 2) after the first drive shaft penetrates the first link hole, the third shaft wall is deformed outward to form a third crimping edge to limit the separation of the fourth rotational pair; and after the second drive shaft penetrates the second link hole, the fourth shaft wall is deformed outward to form a fourth crimping edge to limit the separation of the fifth rotational pair.

7. The inner core assembly of claim 6, wherein: 1) the first profiled groove comprises a distal first guide port, a first cylindrical surface, and a first cut-off groove, the maximum opening width of the first guide port is H11, the diameter of the first cylindrical surface is D11, and the intersection of the first guide port and the first cylindrical surface forms a first bite opening with a width of H12, wherein H11≥D11>H12; 2) the second profiled groove comprises a distal second guide port, a second cylindrical surface, and a second cut-off groove, the maximum opening width of the second guide port is H21, the diameter of the second cylindrical surface is D21, and the intersection of the second guide port and the second cylindrical surface forms a second bite opening with a width of H22, wherein H21≥D21>H22; 3) the one end of the kingpin comprises a pin head embedded in the first cylindrical surface to form a first bite pair, and the other end of the kingpin comprises a pin head embedded in the second cylindrical surface to form a second bite pair.

8. The inner core assembly of claim 7, wherein: 1) the inner core assembly comprises three states: a working state, a critical state, and a separation state, and the drive head comprises a working displacement Lw1 and a critical displacement Le1, wherein Lw1>Le1. 2) Working state: when the driving head is in working displacement Lw1, the pin head of the main pin keeps in contact with the first and second cylindrical surface, i.e. the first and second occlusion pairs are in occlusion state; moving the driving rod can make the first and second jaw heads close or open in the range of 0~A1 angle; 3) Critical state: when the driving head is in critical displacement Le1, continue to move the driving rod from the proximal end to the distal end, at this time the opening angle of the first and second jaw heads reaches the maximum limit angle A1, and Le1 no longer decreases, so that the driving head pushes the first and second jaw tails to move towards the distal end, and in turn pushes the pin head of the main pin to move towards the distal end and opens the first and second occlusion; 4) Separation state: in the critical state, continue to move the driving rod from the proximal end to the distal end, push the pin head of the main pin to move towards the distal end, completely expand the first and second occlusion and slip into the first and second guide openings, i.e. the first and second occlusion pairs are in invalid separation state, so as to realize the separation of the inner rod assembly and the outer tube assembly.

9. A surgical instrument for minimally invasive surgery, the instrument comprising the inner core assembly as claimed in any one of claims 1-8, and further comprising a handle assembly matched therewith; the handle assembly comprises a rotating wheel assembly, a button assembly, a handle rotating shaft and a first handle and a second handle rotating therearound; the outer tube assembly of the inner core assembly is matched with the rotating wheel assembly and the button assembly; the driving rod comprises a driving head, a driving tail and a driving rod extending therebetween, the driving tail is connected with the second handle, the first handle and the second handle rotate around the handle rotating shaft to move the driving tail, and in turn move the driving head, and in turn drive the first, second, third, fourth and fifth rotating pairs to rotate, and in turn drive the first and second jaws to rotate and open or close around the first rotating pair.

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