CN110051428B - Improved surgical instrument head assembly - Google Patents

Abstract

The invention discloses an improved surgical instrument head assembly, which comprises a base, a first jaw and a second jaw, wherein the first jaw and the second jaw are matched with the base; the base comprises a shaft shoulder, a first fixing arm and a second fixing arm, wherein the first fixing arm and the second fixing arm extend to the far end, the first jaw tail and the second jaw tail are clamped between the first fixing arm and the second fixing arm, the first jaw tail and the first fixing arm form a first revolute pair which can be disassembled and reassembled, and the second jaw tail and the second fixing arm form a second revolute pair which can be disassembled and reassembled.

Description

Improved surgical instrument head assembly

Technical Field

The invention relates to a minimally invasive surgical instrument, in particular to an endoscope handheld instrument.

Background

Endoscopic surgery (including hard tube endoscope and fiber endoscope) is that elongated endoscopic hand-held instruments are adopted to enter the body of a patient through a natural cavity or a constructed puncture channel to complete operations of tissue grasping, shearing, separating, blood coagulation, suture closure and the like. The main advantages over traditional open surgery are reduced trauma and pain and accelerated recovery. In the endoscopic surgery, a doctor usually can only touch internal organs of a patient by means of instruments and cannot directly sense the internal organs by hands; in addition, the visual field of the endoscopic surgery doctor is severely limited, and the local area of the working head of the instrument can be observed only by means of an endoscope and an image system. Because the visual field of the doctor is limited in the operation and the tactile feedback is lacked, the method provides high requirements on the aspects of the accuracy, the consistency, the controllability and the like of the endoscope handheld instruments (endoscope scissors, endoscope grasping forceps, endoscope separating forceps and the like).

So far, the reusable endoscope hand-held instrument (multiplexing instrument for short) has the market leading position, and the disposable endoscope hand-held instrument (disposable instrument for short) has relatively few clinical applications. However, many medical documents deeply analyze the problems of the multiplexing apparatus, and a doctor's paper with the title of Safety Evaluation of scientific Instruments, a thesis submitted for the degree of Safety of the device of the duration of the device of the February 2017, which details the unreliable controllability problems in the cleaning, distribution and use of the multiplexing apparatus, such as the fact that the ions in the blood of the human body are very corrosive to the stainless steel multiplexing apparatus, has not been reliable solution so far.

The disposable instrument can effectively solve a plurality of problems of the multiplexing instrument, but the cost of the high-quality disposable instrument is too high. A study paper on Reusable convertible dispersible fibrous Instruments, Minimaty Invasive Surgery, Volume 2014, showed that the Cost of applying Disposable devices was about 10 times the Cost of applying multiplexing devices. The high cost of disposable instruments places a burden on the patient and severely hinders the development of endoscopic surgery. The equipment cost mainly comprises the manufacturing cost, the assembly cost, the sterilization cost, the storage and transportation cost and the like of parts. On the premise of ensuring and even optimizing the functional performance, the cost is very difficult to reduce. One of the most difficult challenges is to improve the head structure of the instrument. To date, a large number of existing endoscopic instruments use pins to rivet to form rotary joints. The riveting of the knuckle pin must be very fine: the first rigidity and the hardness that need to ensure the pin are enough, and the second needs to ensure to rivet firmly in order to prevent that the pin from coming off, and the third needs to ensure that the clearance of pin and matching hole is reasonable, can be in the same direction as smooth rotation. Riveting of the knuckle pin typically requires multiple manual repairs by highly experienced and sophisticated technicians, and multiple verifications and validations, which significantly increases the manufacturing costs of the instrument. Optimally designing and manufacturing the disposable endoscope hand-held instrument with the performance similar to or even superior to that of a multiplexing instrument, and simultaneously remarkably reducing the overall cost, which is very difficult but has great significance.

Disclosure of Invention

Accordingly, to solve the problems of the prior art, an instrument assembly is provided that can effectively reduce manufacturing costs.

In one aspect of the invention, a minimally invasive surgical instrument head assembly comprises a base and first and second jaws mated therewith, the first jaw comprising a first jaw tail and a first jaw wrist connected thereto, the second jaw comprising a second jaw tail and a second jaw wrist connected thereto; the base comprises a shaft shoulder, a first fixing arm and a second fixing arm, the first fixing arm and the second fixing arm extend to the far end, the shaft hole penetrates through the shaft shoulder, the motion base surface and the buckling surface are approximately vertically intersected, and the intersection line of the motion base surface and the buckling surface is basically overlapped with a first central shaft of the shaft hole. The first jaw tail and the second jaw tail are clamped between the first fixing arm and the second fixing arm, the first jaw tail and the first fixing arm form a first rotating pair which can be disassembled and reassembled, and the second jaw tail and the second fixing arm form a second rotating pair which can be disassembled and reassembled.

In one version, the head assembly further comprises a drive head comprising a drive block defined by a first translation surface and a second translation surface, the first drive chute being recessed from the first translation surface toward the interior of the drive block, the second drive chute being recessed from the second translation surface toward the interior of the drive block; the driving head is clamped between the first jaw tail and the second jaw tail, the first driven lug extends from the proximal end of the first jaw tail to the outer part of the jaw tail and is matched with the first driving chute to form a first cam pair, and the second driven lug extends from the proximal end of the second jaw tail to the outer part of the jaw tail and is matched with the second driving chute to form a second cam pair; the driving head can make translational motion in the base, so that the first cam byproduct and the second cam byproduct are driven to slide relatively, and the first jaw and the second jaw are driven to rotate to close or open.

In one particular version, the first drive chute includes a first drive chute proximal opening and the second drive chute includes a second drive chute proximal opening; the opening angle A1 of the first jaw of the head assembly has three value ranges:

the limiting opening angle is Au1, and when A1 is more than or equal to Au1, the first driven lug can be completely separated from the first driving chute;

a critical opening angle Ae1, when a1 ═ Ae1, the first follower lug is aligned with the first drive slot proximal opening;

the working opening angle Aw1 is designed, when A1 is not more than Aw1, the first driven lug and the first driven groove are always kept in contact

In another preferred scheme, the ultimate opening angle Au1, the critical opening angle Ae1 and the design working opening angle Aw1 satisfy the following relationship: au1 > Ae1 >Aw 1.

In yet another embodiment, the first jaw of the head assembly comprises a first blade and a first cutting edge extending from the first jaw wrist to the distal end, the second jaw comprises a second blade and a second cutting edge extending from the second jaw wrist to the distal end, and the first cutting edge and the second cutting edge contact each other when Ax1 isAx 2.

In a further embodiment, the first and second jaws of the head assembly comprise a first and second base pillar extending from the first and second support surfaces towards the outside of the jaws; the first base column comprises a first cylindrical base having a diameter Dr1 and a first narrow body portion having a width Br1, Br1 <Dr 1; the second base column comprises a second cylindrical base having a diameter Dr2 and a second narrow body portion having a width Br2, Br2 <Dr 2;

in another aspect, the first fixed arm of the head assembly includes a first cylindrical surface having a diameter Df1 and a first cutout having a width Bf1, and the second fixed arm includes a second cylindrical surface having a diameter Df2 and a second cutout having a width Bf2, and the dimensions satisfy the following equation: df1 is more than or equal to Dr1 and more than or equal to Bf1 and more than or equal to Br1, and Df2 is more than or equal to Dr2 and more than or equal to Bf2 and more than or equal toBr 2.

In yet another aspect of the invention, an elongate shaft assembly for minimally invasive surgery is provided, the shaft assembly comprising the aforementioned head assembly, further comprising a hollow tube connected to a base, and a drive rod connected to a drive head. The hollow tube may be rigid or flexible and the drive rod may be rigid or flexible. In one implementation, the shoulder of the base includes a fixed wall extending to a proximal end, and the distal end of the hollow tube is shrunk and deformed to cover the exterior of the fixed wall. In one implementation, the drive head and drive rod are connected with a removable snap joint, and the snap joint is restrained within the shaft bore to prevent the snap joint from falling out.

In yet another aspect of the present invention, an instrument product for minimally invasive surgery is presented, the instrument product comprising the aforementioned elongate shaft assembly and further comprising a handle assembly coupled to the elongate shaft assembly. The handle assembly comprises a first handle, a second handle and a handle rotating shaft, the first handle is connected with the hollow pipe, the second handle is connected with the driving rod, the first handle and the second handle can rotate around the handle rotating shaft, so that the driving head is driven to perform translational motion along the direction of the central shaft, the first cam pair is driven to slide relatively, the first cam pair is forced to rotate relative to the second cam pair, the second cam pair is driven to slide relatively, the second cam pair is forced to rotate relative to the second cam pair, and the first jaw head and the second jaw head are rotated to open or close.

Drawings

For a fuller understanding of the nature of the present invention, reference should be made to the following detailed description taken together with the accompanying figures in which:

FIG. 1 is a side schematic view of abase 30;

FIG. 2 is a distal to proximal projection view of thebase 30;

FIG. 3 is a side schematic view of thedrive head 70;

FIG. 4 is a distal to proximal projection view of thedrive head 70;

FIG. 5 is a perspective view of the first jaw 10 (second jaw 20);

FIG. 6 is a schematic side view of thehead assembly 2;

FIG. 7 is an inside projection view of thefirst jaw 10a (second jaw 20 a);

FIG. 8 is a side schematic view of thefirst jaw 10a (second jaw 20 a);

FIG. 9 is a side schematic view of thedrive head 70 a;

FIG. 10 is a cross-sectional view 10-10 of thedrive head 70a of FIG. 9;

FIG. 11 is a schematic view of the disassembly angle of thehead assembly 2 a;

fig. 12 is a schematic view of the critical opening angle state of thehead assembly 2 a;

fig. 13 is a schematic view of thehead assembly 2a in an operating state;

FIG. 14 is a perspective view of thefirst jaw 10b (second jaw 20 b);

FIG. 15 is a distal partial schematic view of thehead assembly 2 b;

FIG. 16 is a side schematic view of thebase 30 d;

FIG. 17 is a cross-sectional view of 17-17 of FIG. 16;

FIG. 18 is a perspective view of thefirst jaw 10d (second jaw 20 d);

FIG. 19 is a distal partial schematic view of thehead assembly 2 d;

FIG. 20 is a side schematic view of thebase 30 e;

FIG. 21 is a perspective view of thefirst jaw 10e (second jaw 20 e);

FIG. 22 is a perspective view of thedrive head 70e of FIG. 2;

FIG. 23 is a projection view of thedrive head 70 e;

FIG. 24 is an assembled schematic view of thehead assembly 2 e;

fig. 25 is a schematic view of the critical opening angle state of thehead assembly 2 e;

FIG. 26 is a side schematic view of the base 30 f;

FIG. 27 is a side schematic view of thefirst jaw 10f (second jaw 20 f);

FIG. 28 is a side schematic view of thedrive head 70 f;

fig. 29 is a schematic view of the head assembly 2f in an operating state;

FIG. 30 is a side schematic view of the base 30 g;

FIG. 31 is a cross-sectional view 31-31 of FIG. 30;

FIG. 32 is a perspective view of the head assembly 2 g;

FIG. 33 is a schematic view of the connection of the base to the hollow tube;

FIG. 34 is a cross-sectional view taken at 34-34 of FIG. 33;

FIG. 35 is a schematic view of the connection scheme of the drive head to the drive rod;

FIG. 36 is a schematic view of an asymmetric snap-fit arrangement of the drive head and drive rod;

FIG. 37 is a schematic view of the drive head in riveted connection with the drive rod;

FIG. 38 is a schematic view of a symmetrical quick-snap-fit arrangement of the drive head and drive rod;

FIG. 39 is a schematic view of a T-shaped quick-connect scheme of the drive head and the drive rod;

fig. 40 is a side schematic view of theinstrument 1;

like reference numerals refer to like parts or components throughout the several views.

Detailed Description

Embodiments of the present invention are disclosed herein, however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, the disclosure herein is not to be interpreted as limiting, but merely as a basis for the claims and as a basis for teaching one skilled in the art how to employ the present invention.

Referring to fig. 1, for convenience, the side next to the operator is defined as the proximal side, and the side further away from the operator is defined as the distal side. For laparoscopic procedures, a piercing cannula assembly (not shown) is typically used to establish surgical access to and from the body of the patient through the body cavity of the patient through which various minimally invasive instruments, such asinstrument 1, may be inserted. One or more cannula assemblies may be used simultaneously during the procedure, and theinstrument 1 may be configured to operate simultaneously with one or more other cannula assemblies depending on the surgical needs.

Example 1:

figures 1-6 depict ahead assembly 2 of a typical endoscopic hand heldinstrument 1. Thehead assembly 2 includes afirst jaw 10, asecond jaw 20, abase 30 and adrive head 70. Thefirst jaw 10 and thesecond jaw 20 are matched with each other and are arranged between thebases 30, and the drivinghead 70 is matched with thefirst jaw 10 and thesecond jaw 20; while thedrive head 70 is mounted in thebase 30, thedrive head 70 can be moved axially and drives thefirst jaw 10, the mutual rotational opening movement or closing movement of thesecond jaw 20.

Fig. 1-2 depict the structure and composition of the base 30 in detail. Thebase 30 includes ashoulder 31 and first and second retainingarms 33, 34 extending to a distal end, the first and second retaining arms forming afork structure 300 having a spacingHb 1. Theaxle hole 32 penetrates through theshoulder 31, and thefirst motion base 371 and thefirst fastening surface 372 are approximately perpendicularly intersected, and the intersection line of thefirst motion base 371 and thefirst fastening surface 372 is basically coincident with the firstcentral axis 37 of theaxle hole 32. The distal end of thefirst fixing arm 33 includes afirst boss 331 having a height Hf1 extending from the first mountingsurface 330 toward thefirst movement base 371; the distal end of said second fixingarm 34 comprises asecond boss 341 of height Hf2 extending from the second mountingsurface 340 towards thefirst movement base 371. The mountingsurface 330, the mountingsurface 340 and thebase surface 371 are substantially parallel. In one embodiment, thefirst protrusion 331 and thesecond protrusion 341 are respectively disposed on two sides of thefastening surface 372 and are asymmetric; thefirst boss 331 and thesecond boss 341 are located on two sides of thebase plane 371 and are asymmetric.

The structure and composition of thedrive head 70 is depicted in detail in fig. 3-4. Thedrive head 70 comprises a secondcentral axis 71, and the firsttransverse plane 711 and the firstlongitudinal plane 712 intersect substantially perpendicularly, with the intersection line substantially coinciding with the secondcentral axis 71. The first and second translation planes 74, 75 are substantially parallel to saidtransverse plane 711 and define adrive block 73 having athickness Hd 1. Thefirst drive lug 740 extends from thetranslation surface 74 to a height Hp1 outside theblock 73; thesecond drive lug 750 extends from thetranslation surface 75 to a height Hp2 outside theblock 73. In one aspect, thefirst drive lug 740 and thesecond drive lug 750 are located on opposite sides of thelongitudinal plane 712 and are asymmetric; thefirst drive lug 740 and thesecond drive lug 750 are located on opposite sides of thetransverse plane 711 and are asymmetrical. The first and second translation surfaces 74, 75 extend proximally to intersect thedrive neck 72.

Fig. 5 depicts in detail the structure and composition of thefirst jaw 10 and thesecond jaw 20. The proximal end of thefirst jaw 10 includes afirst jaw tail 13 of thickness Hj1 defined by a firstouter side 11 and a firstinner side 12. Thefirst base hole 14 is recessed from the firstouter side surface 11 toward the inside of thejaw tail 13, and the first drivengroove 15 is recessed from the firstinner side surface 12 toward the inside of thejaw tail 13. Afirst wrist 16 is integral with thefirst tail 13 and extends distally to form afirst jaw head 19. The proximal end of thesecond jaw 20 includes asecond jaw tail 23 having a thickness Hj2 defined by a secondouter side 21 and a secondinner side 22. Thesecond base hole 24 is recessed inwardly of thejaw tail 23 from the secondouter side surface 21, and thesecond follower groove 25 is recessed inwardly of thejaw tail 23 from the secondinner side surface 22. Thesecond wrist 26 is integrally connected to thesecond tail 23 and extends distally to form asecond jaw head 29. One skilled in the art will readily appreciate that the first (second) jaw head shown may be a separator clamp, grasper, scissors, or the like.

Fig. 6 depicts the composition and assembly of thehead assembly 2. Thefirst jaw 10 and thesecond jaw 20 are mounted in thebase 30, wherein the first mountingsurface 330 matches the firstouter side 11 and the second mountingsurface 340 matches the secondouter side 21. Thefirst boss 331 is matched with thefirst base hole 14 to form a first rotating pair 100 (not shown in the figure); thesecond boss 341 and thesecond base hole 24 are matched to form a second revolute pair 200 (not shown in the figure); the first and second revolute pairs 100 and 200 are not coaxial. Thedrive head 70 is mounted into the base 30 with the firstcentral axis 37 and the secondcentral axis 71 aligned;first translation surface 74 mates with firstinner side 12; thesecond translation surface 75 mates with the secondinner side 22; thefirst driving lug 740 is matched with the first drivengroove 15 to form a first cam pair 700 (not shown in the figure); thesecond driving lug 750 is matched with the second drivengroove 25 to form a second cam set 800 (not shown). The drivinghead 70 can move in translation along the central axis direction, so as to force the first cam pair 700 to slide relatively and drive thefirst jaw 10 to rotate around the first revolute pair 100; forcing the second cam pair 800 to slide relative to each other and thereby driving thesecond jaw 20 to rotate about the second revolute pair 200.

In a specific embodiment, thebase 30, thedrive head 70, thefirst jaw 10 and thesecond jaw 20 satisfy the following relationship: hj1 is more than or equal to HP1, Hj1 is more than or equal to Hf1, Hj2 is more than or equal to HP2, Hj2 is more than or equal to Hf2, Hj1+Hj2+ Hd1+ delta 1 isHb 1. Hj1 is the thickness of the first jaw tail; hj2 is the thickness of the second jaw tail; hd1 is the thickness of the drive block; hb1 is the spacing of the first and second securing arms;δ 1 is a machining error.

Example 2:

fig. 7-12 depict yet anotherhead assembly 2a of the present invention. Thehead assembly 2a includes afirst jaw 10a, asecond jaw 20a, abase 30 and adrive head 70 a.

7-8, thefirst jaw 10a includes afirst wrist 16a having a thickness Hw1 and afirst tail 13a extending proximally to a thickness Ht1 and afirst head 19a extending distally. The proximal end of thefirst jaw tail 13a comprises a first drivenlug 15a extending from the firstinner side surface 12a to the outside of the jaw tail and having aheight Ha 1; and the distal end of saidfirst tail 13a comprises afirst base hole 14a recessed from the firstouter side 11a towards the inside of the tail. Thefirst jaw arm 16a comprises afirst support surface 17 a. Thesecond jaw 20a includes asecond jaw arm 26a having a thickness Hw2 and asecond jaw tail 23a extending a proximal thickness Ht2 and asecond jaw head 29a extending to a distal end. The proximal end of thesecond jaw tail 23a comprises a second drivenlug 25a extending from the secondinner side surface 22a to the outside of the jaw tail and having aheight Ha 2; and the distal end of saidsecond jaw tail 23a comprises asecond base hole 24a which is recessed from the second outerlateral surface 21a towards the inside of the jaw tail. Thesecond jaw arm 26a includes asecond support surface 27 a.

As shown in fig. 9-10, thedrive head 70a includes a secondcentral shaft 71, adrive neck 72a and adrive block 73a extending distally to athickness dimension Hd 2. Thedrive block 73a includes afirst drive chute 740a recessed inwardly from thefirst translation surface 74a and asecond drive chute 750a recessed inwardly from thesecond translation surface 75 a. Thefirst drive chute 740a includes a first chutedistal end 749a and first substantially parallel distal andproximal drive surfaces 743a, 745a extending from the chute distal end to the chute proximal end, with the distal andproximal drive surfaces 743a, 745a forming a first chuteproximal opening 741a having awidth dimension Sr 1. Thesecond drive chute 750a includes a second chutedistal end 759a and substantially parallel seconddistal drive face 753a and secondproximal drive face 755a extending from the chute distal end to the chute proximal end, and thedistal drive face 753a and theproximal drive face 755a form a second chuteproximal opening 751a having awidth dimension Sr 2.

In a specific implementation, thefirst driving chute 740a and thesecond driving chute 750a are respectively located at two sides of the drivingblock 73a and cross each other in an "X" shape, and thefirst driving chute 740a and thesecond driving chute 750a are not communicated or partially communicated.First drive chute 740a andsecond drive chute 750a depicted in fig. 9 and 10 are partially in communication forming a communicatingchannel 760a, with communicatingchannel 760a primarily serving as a process channel for ease of manufacture. Although fig. 9 and 10 depict theslot floor 747a of thefirst drive chute 740a and theslot floor 757a of thesecond drive chute 750a as being coplanar, theslot floor 747a, theslot floor 757a may not be coplanar or may be a non-horizontal or curved structure. Although the first chutedistal end 749a, the second chutedistal end 759a are depicted in fig. 9 as closed distal ends, distal openings may be included.

Referring now to fig. 11-13, thefirst jaw 10a, thesecond jaw 20a are sandwiched between thefirst fixing arm 33 and thesecond fixing arm 34 of thebase 30, thefirst base hole 14a and thefirst boss 331 constitute a firstrevolute pair 100a, and thesecond base hole 24a and thesecond boss 341 constitute a secondrevolute pair 200 a; thedrive head 70a is sandwiched between the first andsecond jaws tails 13, 23, thefirst drive chute 740a mating with the first drivenlug 15a forming a first cam set 700a, and thesecond drive chute 750a mating with the second drivenlug 25a forming a second cam set 800 a; thefirst support surface 17a and thesecond support surface 27a contact each other.

With continued reference to fig. 11, thefirst jaw 10a includes a first disassembled angle Ax1 (the included angle of thefirst jaw 19a relative to thefastening surface 372 when thefirst projection 331 is aligned with thefirst base hole 14 a), and thesecond jaw 20a includes a second disassembled angle Ax2 (the included angle of thesecond jaw 29a relative to thefastening surface 372 when thesecond projection 341 is aligned with thesecond base hole 24 a). Although Ax1 < Ax2 is depicted in FIG. 23, it can be set as Ax1 ≧Ax 2.

In a preferred embodiment, the first andsecond wrists 16a, 26a are shaped and dimensioned such that when Ax1 is Ax2, the first and second support surfaces 17a, 27a match each other and the contact area is as large as possible, so as to ensure the reliability and smoothness of movement; when Ax1 ≠ Ax2, Ax1 and Ax2 have specific values for disengaging thefirst support surface 17a and thesecond support surface 27a from each other. The first andsecond wrists 16a, 26a are suitably shaped and dimensioned so that the first andsecond jaws 10a, 20a can be assembled and disassembled at specific unequal angles, while the opening angles of the first andsecond jaws 10a, 20a are symmetrical when they are in the working condition, thus ensuring that the first and second support surfaces 17a, 27a match each other in any working condition and the contact area is as large as possible, thus ensuring the reliability and smoothness of the movement. Those skilled in the art will appreciate that the configuration and dimension settings of the first andsecond jaw wrists 16a and 26a and the specific values of Ax1 and Ax2 can be obtained by enumeration and experiment, and will not be described in detail herein. Thehead assembly 2a can be rapidly assembled or disassembled, and does not have small pin shafts or other small scattered parts, so that the assembling, disassembling and disassembling efficiency can be improved to a large extent, the assembling cost and the rejection rate of finished products are greatly reduced, and the overall cost of disposable instruments is greatly reduced.

With continued reference to fig. 12-13, in one particular design, the opening angle a1 of thefirst jaw 10a (or thesecond jaw 20a) of thehead assembly 2a is tested by: referring to fig. 12, the angle between the virtual plane of the jaw and the fastening plane is substantially parallel to the rotation axis of the revolute pair. The opening angle A1 comprises three value intervals: a limiting opening angle Au1, a critical opening angle Ae1 and an operatingopening angle Aw 1.

Ultimate opening angle Au 1: there is a limiting opening angle Au1 such that when A1 ≧ Au1, the first drivenlug 15a is fully disengaged from thefirst drive ramp 740a (the second drivenlug 25a is fully disengaged from thesecond drive ramp 750 a).

Critical opening angle Ae 1: there is a critical opening angle Ae1 such that when a1 ═ Ae1, first drivenlug 15a is aligned with first chuteproximal opening 741a (second drivenlug 25a is aligned with second chuteproximal opening 751 a); when a1 > Ae1, the first drivenlug 15a is disengaged from thefirst drive chute 740a (the second drivenlug 25a is disengaged from thesecond drive chute 750 a); when A1 < Ae1, the first drivenlug 15a and the first driving inclinedgroove 740a are matched to form thefirst cam pair 700a (the second drivenlug 25a and the second driving inclinedgroove 750a are matched to form thesecond cam pair 800 a).

Working opening angle Aw 1: the operational opening angle Aw1 is present such that when A1 ≦ Aw1, the first drivenlug 15a is always in contact with thefirst drive chute 740a (the second drivenlug 25a is always in contact with thesecond drive chute 750 a).

In one embodiment, Au1 > Ae1 >Aw 1. In a specific embodiment, Aw1 is ≦ 40.

Thehead assembly 2a can be conveniently and rapidly disassembled and assembled, and fine pin shafts or other fine scattered parts do not need to be installed or disassembled in the assembling and disassembling processes, so that the assembling and disassembling efficiency can be greatly improved, the assembling cost and the rejection rate of finished products are greatly reduced, and the overall cost of disposable instruments is greatly reduced. As shown in fig. 11-13, in brief, thefirst boss 331 is first matched with thefirst base hole 14a to form the firstrotating pair 100a, and thesecond boss 341 is matched with thesecond base hole 24a to form the secondrotating pair 200 a; the first jaw is then rotated, the second jaw sets it to the critical opening angle Ae1, and finally thedrive head 70 is moved so that the first slave ear bothlugs 15a enter thefirst drive chute 740a through the first drive chuteproximal opening 741a and mate therewith to form the first cam set 700a, while the second slave ear bothlugs 25a enter thesecond drive chute 750a through the second drive chuteproximal opening 751a and mate therewith to form the second cam set 800 a. As will be readily appreciated by those skilled in the art, a limit can be added to limit the opening angle A1 of thehead assembly 2a to the working opening angle Aw1 during use of theinstrument 1, which effectively prevents thefirst jaw 10a (thesecond jaw 20a) from being pulled out during operation.

Example 3:

fig. 14-15 depict yet anotherhead assembly 2 b. Thehead assembly 2b comprises first andsecond jaws 20b, abase 30 and adrive head 70 a.

Fig. 14 depicts in detail the structure and composition of thefirst jaw 10b and thesecond jaw 20 b. Thefirst jaw 10b includes afirst jaw wrist 16b and afirst jaw tail 13b extending to a proximal end and afirst blade 19b extending to a distal end. The proximal end of thefirst jaw tail 13b comprises a first drivenlug 15b extending from the firstinner side surface 12b to the outside of the jaw tail; and the distal end of saidfirst tail 13b comprises afirst base hole 14b which is recessed from the firstouter side 11b towards the inside of the tail. Thefirst blade 19b includes afirst cutting edge 18 b. Thesecond jaw 20b includes asecond wrist 26b and asecond tail 13b extending proximally and asecond blade 29b extending distally; the proximal end of thesecond jaw tail 23b comprises a second drivenlug 25b extending from the secondinner side surface 22b to the outside of the jaw tail; and the distal end of saidsecond jaw tail 23b comprises asecond base hole 24b which is recessed from the second outerlateral surface 21b towards the inside of the jaw tail.Second blade 29b includes asecond cutting edge 28 b.

The first and 10a, thesecond jaw 20a are clamped between the first and secondfixed arms 33, 34 of thebase 30, wherein thefirst base hole 14b and thefirst boss 331 form a first revolute pair 100b (not shown), and thesecond base hole 24b and thesecond boss 341 form a second revolute pair 200b (not shown); thedrive head 70a is sandwiched between the first andsecond jaws 13, 23, wherein thefirst drive chute 740a mates with the first drivenlug 15b to form a first cam set 700b (not shown), and thesecond drive chute 750a mates with the second drivenlug 25b to form a second cam set 800b (not shown); the first cutting edge 17b and the second cutting edge 27b are in contact with each other. Similarly, thehead assembly 2b can be rapidly assembled or disassembled, and does not have small pin shafts or other small scattered parts, so that the assembling, disassembling and disassembling efficiency can be improved to a large extent, the assembling cost and the rejection rate of finished products are greatly reduced, and the overall cost of disposable instruments is greatly reduced.

Example 4:

fig. 16-19 depict yet anotherhead assembly 2 d. Thehead assembly 2d includes afirst jaw 10d, asecond jaw 20d, abase 30d and adrive head 70.

Fig. 16-17 depict the structure and composition of thebase 30d in detail. Thebase 30d is similar in structure and composition to thebase 30. Briefly, thebase 30d includes ashoulder 31, ashaft hole 32, afirst motion base 371, afirst fastening surface 372, afirst fixing arm 33, and asecond fixing arm 34. The distal end of thefirst fixing arm 33 includes afirst fixing hole 331d recessed from the first mountingsurface 330 toward the inside of the first fixing arm; the distal end of thesecond fixing arm 34 includes asecond fixing hole 341d recessed from the second mountingsurface 340 toward the inside of the second fixing arm. That is, thefirst boss 331 of thesusceptor 30 is replaced with thefirst fixing hole 331d, and thesecond boss 341 of thesusceptor 30 is replaced with thesecond fixing hole 341d to form anew susceptor 30 d.

Fig. 18 depicts in detail the structure and composition of thefirst jaw 10d and thesecond jaw 20 d. Thefirst jaw 10d (second jaw 20d) is similar in structure to the first jaw 10 (second jaw 20) described above. Briefly, thefirst jaw 10d includes a firstouter side 11, a firstinner side 12, afirst jaw tail 13, afirst jaw wrist 16, afirst jaw head 19 and a first drivenslot 15, and afirst base pillar 14d extends from the firstouter side 11 to the outside of the jaw tail. A newfirst jaw 10d is formed by replacing thefirst base hole 14 of thefirst jaw 10 with thefirst base pillar 14 d. Thesecond jaw 20d comprises a secondouter side surface 21, a secondinner side surface 22, asecond jaw tail 23, asecond jaw wrist 26, asecond jaw head 29 and a second drivengroove 25, and asecond base column 24d extends and protrudes from the secondouter side surface 21 to the outside of the jaw tail. A newsecond jaw 10d is formed by replacing thesecond base hole 14 of thesecond jaw 20 with thesecond base post 24 d.

Fig. 19 depicts the composition and assembly of thehead assembly 2 d. Thefirst jaw 10d and thesecond jaw 20d are mounted in thebase 30d with the first mountingsurface 330 matching the firstouter side 11 and the second mountingsurface 340 matching the secondouter side 21. Thefirst fixing hole 331d is matched with thefirst base pillar 14d to form a firstrotating pair 100 d; thesecond fixing hole 341d is matched with thesecond base cylinder 24d to form a secondrevolute pair 200d (not shown). Thedrive head 70 is mounted into thebase 30d with the first and secondcentral axes 37, 71 aligned;first translation surface 74 mates with firstinner side 12; thesecond translation surface 75 mates with the secondinner side 22; thefirst driving lug 740 is matched with the first drivengroove 15 to form a first cam pair 700 (not shown in the figure); thesecond driving lug 750 is matched with the second drivengroove 25 to form a second cam set 800 (not shown). Thehead assembly 2d can be quickly assembled or disassembled, and does not have small pin shafts or other small scattered parts, so that the assembling, disassembling and disassembling efficiency can be improved to a large degree.

Example 5:

fig. 20-25 depict yet anotherhead assembly 2 e. Thehead assembly 2e includes afirst jaw 10e, asecond jaw 20e, abase 30e and adrive head 70 e. As shown in fig. 20, thebase 30e is substantially the same as thebase 30d except for the arrangement of the first (second) fixing hole. Referring now to fig. 16, 17 and 20, in brief, the base 30b includes ashoulder 31, ashaft hole 32, afirst motion base 371, afirst fastening surface 372, afirst fixing arm 33 and asecond fixing arm 34. The distal end of thefirst fixing arm 33 thereof includes afirst fixing hole 331e recessed from the first mountingsurface 330 toward the inside of the first fixing arm; the distal end of thesecond fixing arm 34 thereof includes asecond fixing hole 341e recessed from the second mountingsurface 340 toward the inside of the second fixing arm. Thefirst fixing hole 331e includes a firstcylindrical surface 333e having a diameter Df1 and afirst cutout 334e having a width Bf1, thecutout 334e cutting a portion of thefirst fixing hole 331e to form a half-open structure. Thesecond fixing hole 341e includes a secondcylindrical surface 343e having a diameter Df2 and asecond slit 344e having a width Bf2, theslit 344e cutting a portion of thesecond fixing hole 341e to form a half-open structure.

As shown in fig. 21, thefirst jaw 10e comprises afirst jaw wrist 16e and afirst jaw tail 13e connected thereto and extending proximally and afirst jaw head 19 extending distally; the proximal end of thefirst jaw tail 13e comprises a first drivenlug 15e extending from the firstouter side 11 to the outside of the jaw tail. Thefirst jaw arm 16e comprises afirst base 14e extending from afirst support surface 17e towards the outside of the jaw arm. Thefirst base pillar 14e includes a firstcylindrical base 142e having a diameter Dr1 and a firstnarrow body portion 141e having a width Br1, Br1 <Dr 1. Thesecond jaw 20e comprises asecond jaw wrist 26e and asecond jaw tail 23e connected thereto and extending proximally and asecond jaw head 29 extending distally; the proximal end of thesecond jaw tail 23e comprises a second drivenlug 25e extending from the second outer side surface 21e outwardly of the jaw tail. Thesecond jaw arm 26e comprises asecond base column 24e extending from thesecond support surface 27e towards the outside of the jaw arm, thesecond base column 24e comprising a secondcylindrical base 242e with a diameter Dr2 and a secondnarrow body portion 241e with a width Br2, Br2 <Dr 2. In a specific design scheme, Df1 is more than or equal to Dr1 and more than Bf1 is more than or equal to Br1, and Df2 is more than or equal to Dr2 and more than Bf2 is more than or equal toBr 2.

As shown in fig. 22-23, thedrive head 70e includes a secondcentral shaft 71. Thedrive head 70e also includes adrive neck 72e and first andsecond drive blocks 77e, 78e connected thereto and extending distally. Thefirst drive block 77e, thesecond drive block 78e and thedrive neck 72e form a clevis arrangement. Thefirst drive block 77e includes afirst translation surface 74e and afirst drive chute 740e recessed inwardly of thefirst drive block 77e from thetranslation surface 74e, thefirst drive chute 740e includes a first chutedistal end 749e and first substantially parallel distal andproximal drive surfaces 743e, 745e extending from the chute distal end to the chute proximal end, and the distal andproximal drive surfaces 743e, 745e form a first chuteproximal opening 741e having awidth dimension Sr 1.

Thesecond drive block 78e includes asecond translation surface 75e and asecond drive chute 750e recessed from thetranslation surface 75e inwardly of thesecond drive block 78 e. Thesecond drive chute 750e is recessed inwardly of the drive block from thesecond translation plane 75e, thesecond drive chute 750e includes a second chutedistal end 759e and generally parallel seconddistal drive face 753e and secondproximal drive face 755e extending from the chute distal end to the chute proximal end, and thedistal drive face 753e and theproximal drive face 755e form a second chuteproximal opening 751e having awidth dimension Sr 2. In a specific implementation, the projections of thefirst drive chute 740e and thesecond drive chute 750e onto the motion base plane parallel to thefirst translation plane 74e (thesecond translation plane 75e) intersect each other in an "X" shape, although the first chutedistal end 749e and the second chutedistal end 759e are depicted in fig. 30 as closed distal ends, but may also include distal openings.

Referring now to fig. 24-25, thefirst jaw 10e, thesecond jaw 20e are sandwiched between thefirst fixing arm 33 and thesecond fixing arm 34 of thebase 30e, wherein thefirst base column 14e and thefirst fixing hole 331e constitute a firstrevolute pair 100e, and thesecond base column 24e and thesecond fixing hole 341e constitute a secondrevolute pair 200 e; the first andsecond tangs 13 and 23 are sandwiched between the first and second drive blocks 77e and 78e of thedrive head 70e, with thefirst drive chute 740e mating with the first drivenlug 15e to form the first cam set 700e and thesecond drive chute 750e mating with the second drivenlug 25e to form the second cam set 800 e.

Similarly, thehead assembly 2e can be quickly assembled or disassembled, and does not have small pin shafts or other small scattered parts, so that the assembly, disassembly and disassembly efficiency can be improved to a greater degree. Briefly, thedrive head 70e is first loaded into the base 30 e; then the jaw assembly 3e is arranged in thebase 30e, wherein the first narrow body part of the first base column is aligned with the first cut of the first fixing hole, the second narrow body part of the second base column is aligned with the second cut of the second fixing hole, and thefirst jaw 10e (thesecond jaw 20e) is arranged and rotated to form a first rotating pair and a second rotating pair; the drive head is then set to the critical opening angle Ae1 and thefirst jaw 10e (second jaw 20e) is then rotated so that the first drive lug enters the first drive chute via the first chute proximal opening to form a first cam set and the second drive lug enters the second drive chute via the second chute proximal opening to form a second cam set. The assembly and disassembly methods are readily understood by those skilled in the art with reference to fig. 24-25 in conjunction with the foregoing and will not be described in detail herein.

Example 6:

fig. 26-29 depict yet another head assembly 2 f. The head assembly 2f includes afirst jaw 10f, asecond jaw 20f, abase 30f, and adrive head 70 f.

Thebase 30f is substantially the same as the base 30 except for the provision of the first (second) boss. Referring now to fig. 1, fig. 2 and fig. 26, in brief, thebase 30f includes ashoulder 31, ashaft hole 32, afirst motion base 371, afirst fastening surface 372, afirst fixing arm 33 and asecond fixing arm 34. The distal end of thefirst fixing arm 33 thereof includes afirst boss 331f extending from the first mountingsurface 330 toward the firstmotion base surface 371; the distal end of thesecond fixing arm 34 thereof includes asecond projection 341f extending from the second mountingsurface 340 toward thefirst movement base 371. Thefirst boss 331f includes a first stationarycylindrical portion 333f having a cross-sectional diameter Df3 and a firstnarrow body portion 334f having a cross-sectional width Bf3, wherein Bf3 <Df 3. Thesecond boss 341f includes a second stationarycylindrical portion 343f having a cross-sectional diameter Df4 and a secondnarrow body portion 344f having a cross-sectional width Bf4, wherein Bf4 <Df 4.

As shown in fig. 27, thefirst jaw 10f (second jaw 20f) is similar to the first jaw 10c (second jaw 20c), differing primarily in the provision of the first (second) base aperture. In summary, thefirst jaw 10f includes a first outer side 11c, a firstinner side 12c, afirst jaw tail 13c, afirst jaw wrist 16c, and afirst jaw head 19. Thefirst jaw tail 13c further comprises afirst base hole 14f recessed from the first outer side surface 11c towards the inside of the jaw tail and a first drivenlug 15c extending from the firstinner side surface 12c towards the outside of the jaw tail. Thefirst base hole 14f includes a firstcylindrical base surface 142f having a diameter Dr3 and afirst cutout 141f having a width Br3, thefirst cutout 141f cutting a portion of the firstcylindrical base surface 142f to form a semi-open structure. Thesecond jaw 20f includes a second outer side surface 21c, a secondinner side surface 22c, asecond jaw tail 23c, asecond jaw wrist 26c, and asecond jaw head 29. Thesecond jaw tail 23c further comprises asecond base hole 24f recessed from the second outer side surface 21c towards the inside of the jaw tail and a second drivenlug 25c extending from the secondinner side surface 22c towards the outside of the jaw tail. Thesecond base hole 24f includes a secondcylindrical base surface 242f having a diameter Dr4 and asecond cutout 241f having a width Br4, thesecond cutout 241f cutting a portion of the secondcylindrical base surface 242f to form a half-open structure. In a specific design scheme, Dr3 is more than or equal to Df3 and Br3 is more than or equal toBf 3.

As shown in fig. 28, thedrive head 70f is similar in structure and composition to thedrive head 70a, thedrive head 70f including adrive neck 72a, a drive block 73f, afirst translation surface 74a and asecond translation surface 75a (not shown). Afirst drive chute 740f is recessed fromfirst translation surface 74a inwardly of the drive block,first drive chute 740f includes a first chutedistal end 749f and first substantially parallel distal 743f and proximal 745f drive surfaces extending from the chute distal end to the chute proximal end, with distal 743f and proximal 745f drive surfaces forming a first chuteproximal opening 741f having awidth dimension Sr 1. Thesecond drive chute 750f is recessed inwardly of the drive block from thesecond translation plane 75a, thesecond drive chute 750f includes a second chute distal end 759f and generally parallel seconddistal drive face 753f and secondproximal drive face 755f extending from the chute distal end to the chute proximal end, and saiddistal drive face 753f and saidproximal drive face 755f form a second chuteproximal opening 751f having awidth dimension Sr 2.

Referring now to fig. 29, thefirst jaw 10f and thesecond jaw 20f are sandwiched between thefirst fixing arm 33 and thesecond fixing arm 34 of thebase 30f, thefirst base pillar 14f and thefirst fixing hole 331f constitute afirst rotation pair 100f, and thesecond base pillar 24f and thesecond fixing hole 341f constitute asecond rotation pair 200 f. The first andsecond tangs 13, 23 are sandwiched between the first and second drive blocks 77f, 78f of thedrive head 70f, with thefirst drive chute 740f mating with the first drivenlug 15f to form thefirst cam set 700f and thesecond drive chute 750f mating with the second drivenlug 25f to form the second cam set 800 f.

Similarly, the head assembly 2f can be quickly assembled or disassembled, and does not have small pin shafts or other small scattered parts, so that the assembly, disassembly and disassembly efficiency can be improved to a greater degree. Briefly, thedrive head 70f is first loaded into the base 30 f; thefirst jaw 10f and thesecond jaw 20f are then placed into thebase 30f with thefirst cut 141f aligned with the firstnarrow body portion 334f and thesecond cut 241f aligned with the secondnarrow body portion 344f, and the jaw assembly 3f is placed and rotated to form first and second revolute pairs; the drive head is then set to a critical displacement and the rotating jaw assembly 3f is then rotated so that the first drive lug enters the first drive chute via the first chute proximal opening to form a first cam set and the second drive lug enters the second drive chute via the second chute proximal opening to form a second cam set. The assembly and disassembly methods are readily understood by those skilled in the art with reference to fig. 37 in conjunction with the foregoing and will not be described in detail herein.

When the head component 2f is operated, the firstrotating pair 100f and thefirst jaw 19 are respectively located at two sides of the bucklingsurface 372, and when thehead components 2a,2b,2d,2e are operated, the first jaw and the first rotating pair are located at the same side of the bucklingsurface 372.

Example 7:

fig. 30-32 depict yet another head assembly 2g of the present invention. The head assembly 2g includes afirst jaw 10a and asecond jaw 20g, abase 30g and adrive head 70 a.

With reference to fig. 1-2, 16-17, and 30-31, thebase 30g is substantially identical in structure and composition to the base 30(30 d). Briefly, thebase 30g includes ashoulder 31, ashaft hole 32, afirst motion base 371, afirst fastening surface 372, afirst fixing arm 33, and asecond fixing arm 34. The distal end of thebase 30g includes afirst boss 331 projecting from the first mountingsurface 330 toward the exterior of the first retaining arm. The distal end of thebase 30g includes asecond fixing hole 341d recessed from the second mountingsurface 340 toward the inside of the second fixing arm. Thesecond jaw 20g is substantially identical in structure and composition to thesecond jaw 20a, and thesecond base hole 24a of thesecond jaw 20a is replaced with asecond base post 24d to constitute thesecond jaw 20g (as understood with reference to fig. 7, 18, and 32).

Referring now to fig. 32, thefirst jaw 10a and thesecond jaw 20g are sandwiched between thefirst fixing arm 33 and thesecond fixing arm 34 of thebase 30g, the firstouter side surface 11a is matched with the first mountingsurface 330, the secondouter side surface 21a is matched with the second mountingsurface 340, thefirst boss 331 and thefirst base hole 14a constitute afirst rotation pair 100a, and thesecond fixing hole 341d and thesecond base column 24d constitute asecond rotation pair 200 d. The firstrevolute pair 100a and the secondrevolute pair 200d are not coaxial. The drivinghead 70a is clamped between the firstinner side 12 and the secondinner side 22, the first driving inclinedgroove 740a and the first drivenlug 15a are matched to form afirst cam pair 700a (not shown in the figure), and the second driving inclinedgroove 750a and the second drivenlug 25a are matched to form asecond cam pair 800 a. Similarly, the head assembly 2g can be quickly assembled or disassembled, and does not have small pin shafts or other small scattered parts, so that the assembly, disassembly and disassembly efficiency can be improved to a large extent.

It will be appreciated by those skilled in the art that various alternatives or combinations of first (second) bosses, first (second) base holes, first (second) base posts, first (second) fixing holes, first (second) cutouts, and first (second) narrow body features may be substituted or combined to create different designs. For example, the first rotating pair may be composed of the first boss and the first base hole, and may also be composed of the first fixing hole and the first base pillar. Based upon the foregoing description, those skilled in the art will appreciate that the following general language is set forth as follows:

in summary, the first revolute pair includes a first outer pair (e.g. the fixing hole on the fixing arm or the base hole on the jaw tail) and a first inner pair (e.g. the boss on the fixing arm or the base post on the jaw tail), and similarly, the second revolute pair includes a second outer pair and a second inner pair. In one arrangement, the first outer pair comprises a partial cylindrical mounting surface and a cut-out feature, the first inner pair comprises a partial cylindrical body and a narrow body feature, the partial cylindrical mounting surface and the partial cylindrical body comprise a first revolute pair, and when the first revolute pair is rotated to align the narrow body feature and the cut-out feature, the first revolute pair can be disengaged and rotationally disassembled. When the first revolute pair can be rotationally disassembled, the second revolute pair does not need to contain the narrow body feature and the cut-out feature, and still can be conveniently disassembled. Of course, the second revolute pair may likewise include a narrow body feature and a cut-out feature. Different combinations may change the assembly method of the components or the refined performance differences, and further combinations and substitutions of the distinguishing technical features are also conceivable. For economy of space, it is not exhaustive here.

In yet another aspect of the invention, a head assembly includes a first jaw, a second jaw, and a base. The base comprises a shaft shoulder, a first fixing arm and a second fixing arm, the first fixing arm and the second fixing arm extend to the far end, the shaft hole penetrates through the shaft shoulder, the motion base surface and the buckling surface are approximately vertically intersected, and the intersection line of the motion base surface and the buckling surface is basically overlapped with a first central shaft of the shaft hole. The first jaw comprises a first jaw tail and the second jaw comprises a second jaw tail; the first and second jaw tails are sandwiched between the first and second fixed arms and are free to contact without additional pinning or additional securing means.

In an alternative embodiment, the first and second tangs are sandwiched between the first and second fixed arms, wherein the first tang and the first fixed arm form a first under-constrained revolute pair and the second tang and the second fixed arm form a second under-constrained revolute pair.

In a specific embodiment, the first under-constrained revolute pair comprises a first outer cylindrical surface and a first inner cylindrical surface; the first rotation axis of the first under-constrained revolute pair is approximately parallel to the fastening plane and approximately perpendicular to the motion base plane; the first outer and inner cylinders contain 2 degrees of freedom, namely rotational freedom about the first axis of rotation and translational freedom along the first axis of rotation. Similarly, in a specific embodiment, the second under-constrained revolute pair comprises a second outer cylindrical surface and a second inner cylindrical surface; the second rotation axis of the second under-constrained revolute pair is substantially parallel to the fastening plane and substantially perpendicular to the motion base plane; the second outer and inner cylinders contain 2 degrees of freedom, namely a rotational degree of freedom about the second axis of rotation and a translational degree of freedom along the second axis of rotation.

The two members constituting the revolute pair (i.e., the fixed arm and the jaw tail described in the present invention) are generally studied as rigid bodies in the linkage mechanics, and the two members constituting the revolute pair allow only a rotational degree of freedom about the rotational axis of the revolute pair without other degrees of freedom in the mechanics. The extensive use of standard revolute pairs in minimally invasive surgical instruments has led to the fact that the "riveting of the articulation pins" described in the background is usually done by multiple manual repairs, verified and confirmed by highly experienced technicians, which greatly increases the manufacturing costs of the instruments.

In the invention, two components (the fixing arm and the jaw tail) forming the revolute pair are taken as elastic bodies for research, the revolute pair is allowed to have 2 degrees of freedom, and the first jaw tail and the second jaw tail are clamped between the first fixing arm and the second fixing arm and are in free contact without additional pin shaft fixing or additional fixing measures by utilizing the elastic deformation of the fixing arm and the stress characteristics of a minimally invasive surgical instrument in working. By utilizing the elastic deformation self-adaptive capacity of the fixed arm, the first (second) under-constrained revolute pair can ensure that the connection part can firmly fall off and can smoothly rotate.

It will be appreciated by those skilled in the art that the first (second) boss, the first (second) base post, and the first (second) inner post, the first (second) base hole, and the first (second) fixing hole disclosed in examples 1-9 are equivalent to the first (second) outer cylindrical surface.

Those skilled in the art will appreciate that there are a variety of methods for manufacturing the base 30(30D,30e,30f,30g), the drive head 70(70a,70e,70f), such as removing material from a metal bar (e.g., milling chips) or welding a plurality of parts together, or using 3D printing. To reduce the manufacturing cost of the parts to a greater extent, it is preferable to produce the base 30(30d,30e,30f,30g) and the driver head 70(70a,70e,70f) by metal powder injection molding (MIM process for short) or metal casting (MC process for short) or high-strength plastic injection molding (IM process for short). Particularly, the MIM process is adopted for mass production, so that the requirements on precision and strength are met, and the cost of a single piece is greatly reduced. In another preferred embodiment, the driving head 70(70a,70e,70f) is slightly modified and may be manufactured by stamping from sheet metal.

In another aspect of the invention, an elongate shaft assembly for minimally invasive surgery is provided comprising any one of the head assemblies described above, further comprising a hollow tube connected to a base of the head assembly, and a drive rod connected to a drive head of the head assembly. In one embodiment, as shown in FIGS. 33-34,hollow tube 40 comprises adistal tube end 41 and aproximal tube end 49 and atube wall 45 extending therebetween, saidtube wall 45 defining acentral bore 46 substantially concentric with said axial bore 32, saiddistal tube end 41 being connected to saidshoulder 31. It should be understood by those skilled in the art that the base 30(30d,30e,30f,30g) and thehollow tube 40 may be attached by a variety of means including, but not limited to, welding, screwing, gluing, etc. As shown in fig. 34, theshoulder 31 preferably further includes a retainingwall 35 extending proximally. In an alternative embodiment, the outer surface of the fixingwall 35 further comprises one or more recessedportions 351, and/or one or more raisedportions 353; however, the outer surface of the fixingwall 35 may be a smooth plane or curved surface without a convex-concave structure. In an alternative embodiment, thehollow tube 40 is made of a thermoplastic material, and then thedistal end 41 of thehollow tube 40 is coated on the outer surface of the fixingwall 35 by glue bonding, interference fit (heat-assisted assembly is possible), or two-shot molding (as shown in fig. 34). The secondary injection molding method is to put the base into a designed injection mold in advance, and then inject thehollow tube 40 to connect it into a whole. In yet another alternative, thehollow tube 40 is made of a metal material (e.g., stainless steel material), the tubedistal end 41 of thehollow tube 40 is sleeved on the outer surface of the fixingwall 35, and thehollow tube 40 and the fixingwall 35 are connected by a pressing method, for example, a pressing tool or a hydraulic tool is used to apply a pressing force on the outer circumference of the tubedistal end 41 to force the tubedistal end 41 to contract and deform inwardly to connect with the fixingwall 35.

In one version, as shown in fig. 35-39, thedrive rod 80 includes a roddistal end 81 and a rodproximal end 89 with arod portion 85 extending therebetween, the rodproximal end 89 including anannular slot 88 substantially perpendicular to the drive rod axis, the roddistal end 81 being connected to thedrive neck 72, thedrive rod 80 axis being substantially coincident with the secondcentral axis 71. It will be appreciated by those skilled in the art that there are a variety of methods of attaching the drive head 70(70a,70e,70f) to thedrive rod 80, including but not limited to welding, threading, mechanical staking (as shown in fig. 37) and the like. As shown in fig. 36, a snap-fit connection is preferably used between the drive head 70(70a,70e,70f) and thedrive rod 80 to facilitate manufacturing and quick assembly. In one implementation, thedrive neck 72 further includes one or more male 723 and female 721 buttons extending to the proximal end, and thedistal stem 81 includes a male 813 and female 811 button. As shown in FIG. 36,male snap 723 mates withfemale snap 811 andfemale snap 721 mates with male snap 813 to form a snap fitting 810, wherein snap fitting 810 is configured to have an outer circumference dimension substantially equal to an inner diameter of shaft bore 32 and wherein, during operation of the elongate shaft assembly, snap fitting 810 is always constrained within shaft bore 32, thereby effectively preventing disengagement of snap fitting 810. The snap joint 810 depicted in fig. 36 is composed of asymmetrical male and female buttons, but may be composed of symmetrical male and female buttons (as shown in fig. 38). In another implementation, the snap fitting 810 is secured with additional welding or glue, and the snap fitting 810 is not necessarily confined within theaxial bore 32. In yet another embodiment, as shown in FIG. 39, thedrive neck 72 of thedrive head 70 includes a semi-enclosed T-shapedslot 720c and thedistal stem end 81 includes a matingannular slot 84, the T-shapedslot 720c and theannular slot 84 mating to form a T-joint 840.

In another aspect of the invention, there is provided a hand-held instrument for use in minimally invasive surgery comprising an elongate shaft assembly of any of the preceding claims, and further comprising arotatable wheel 3 connected to the elongate shaft assembly, afirst handle 4 and asecond handle 5. As shown in fig. 40, in one implementation, thehandheld device 1 includes any one of the head assemblies, and further includes ahollow tube 40 connected to a base thereof, and a drivingrod 80 connected to a driving head thereof, wherein the tubeproximal end 49 is connected to therotating wheel 3 and thefirst handle 4 at the same time, the rodproximal end 89 is connected to thesecond handle 5, and thefirst handle 4 and thesecond handle 5 are engaged with each other and can rotate around a handle rotating shaft, so that the drivingrod 80 and thehollow tube 40 generate axial relative movement, and the driving head is forced to move axially, and thus relative sliding is generated in the first cam pair (second cam pair), and the first jaw (second jaw) is driven to rotate around the first rotating pair (second rotating pair), and opening and closing motions of the first jaw and the second jaw are realized. In another embodiment, theinstrument 1 further comprises an insulating tube covering the outer surface of thehollow tube 40, the metal electrode is connected to the hollow tube or the driving rod via a conductive spring, and when the metal electrode assembly is connected to the high-frequency electrosurgical device, theinstrument 1 can be used for performing electrocoagulation, electrosection, and the like.

While the elongate shaft assembly depicted in fig. 40 is rigid, thehollow tube 40 and driverod 80 can be replaced with flexible materials or flexible mechanisms, and the shaft assembly of the elongate shaft assembly exhibits overall flexibility, the instrument can be used for single bore transumbilical, urological, bronchial or digestive system procedures. The prior art to date has disclosed a wide variety of handle assemblies for minimally invasive surgery, with minor adaptations for connecting and driving the elongate shaft assembly of the present invention, and will not be described in detail.

Many different embodiments and examples of the invention have been shown and described. One of ordinary skill in the art can adapt the methods and apparatus described herein by making appropriate modifications without departing from the scope of the invention. Several modifications have been mentioned, and other modifications will occur to those skilled in the art. The scope of the invention should, therefore, be determined with reference to the appended claims, and not be construed as limited to the details of structure, materials, or acts shown and described in the specification and drawings.

Claims (9)

1. An improved surgical instrument head assembly, the head assembly comprising a base and first and second jaws mated therewith, wherein the first jaw comprises a first jaw tail and a first jaw wrist connected thereto, and the second jaw comprises a second jaw tail and a second jaw wrist connected thereto; the base comprises a shaft shoulder, a first fixing arm and a second fixing arm which extend to the far end, the first jaw tail and the second jaw tail are clamped between the first fixing arm and the second fixing arm, the first jaw tail and the first fixing arm form a detachable and remounted first rotating pair, and the second jaw tail and the second fixing arm form a detachable and remounted second rotating pair; the drive head includes a drive block defined by a first translation surface from which the first drive chute is recessed toward the interior of the drive block and a second translation surface from which the second drive chute is recessed toward the interior of the drive block; the driving head is clamped between the first jaw tail and the second jaw tail, the first driven lug extends from the proximal end of the first jaw tail to the outer part of the jaw tail and is matched with the first driving chute to form a first cam pair, and the second driven lug extends from the proximal end of the second jaw tail to the outer part of the jaw tail and is matched with the second driving chute to form a second cam pair; the driving head can make translational motion in the base, so that the first cam byproduct and the second cam byproduct are driven to slide relatively, and the first jaw and the second jaw are driven to rotate to close or open.

2. The head assembly of claim 1, wherein said first drive chute includes a first drive slot proximal opening and said second drive chute includes a second drive slot proximal opening; the opening angle A1 of the first jaw of the head assembly has three value ranges:

the limiting opening angle is Au1, and when A1 is more than or equal to Au1, the first driven lug can be completely separated from the first driving chute;

a critical opening angle Ae1, when a1= Ae1, the first follower lug is aligned with the first drive slot proximal opening;

the working opening angle Aw1 is designed, and when A1 is not more than Aw1, the first driven lug and the first driven groove are always kept in contact.

3. The header assembly of claim 2, wherein the ultimate opening angle Au1, critical opening angle Ae1, design operating opening angle Aw1 satisfy the following relationship: au1 > Ae1 > Aw 1.

4. The head assembly of claim 1, wherein the first jaw comprises a first disassembly angle Ax1, and the second jaw comprises a second disassembly angle Ax 2; the shapes and sizes of the first and second jaw arms satisfy the following relations:

when Ax1 is equal to Ax2, the first and second wrist are in contact with each other;

when Ax1 ≠ Ax2, a specific value of Ax1 and Ax2 exists to separate the first jaw wrist and the second jaw wrist from each other.

5. The head assembly of claim 3, wherein the first jaw comprises a first blade and a first cutting edge extending from the first wrist to the distal end, and the second jaw comprises a second blade and a second cutting edge extending from the second wrist to the distal end, the first and second cutting edges contacting each other when Ax1 is Ax 2.

6. The head assembly of claim 1, wherein the first and second jaws comprise first and second base posts extending from the first and second support surfaces outwardly of the first and second jaws; the first base column comprises a first cylindrical base having a diameter Dr1 and a first narrow body portion having a width Br1, Br1 < Dr 1; the second base column comprises a second cylindrical base having a diameter Dr2 and a second narrow body portion having a width Br2, Br2 < Dr 2.

7. The head assembly of claim 6, wherein said first retaining arm includes a first cylindrical surface having a diameter Df1 and a first cutout having a width Bf1, and said second retaining arm includes a second cylindrical surface having a diameter Df2 and a second cutout having a width Bf2, the dimensions of which satisfy the following equation:

Df1≥Dr1＞Bf1≥Br1，Df2≥Dr2＞Bf2≥Br2。

8. an elongated shaft assembly for minimally invasive surgery, wherein the elongated shaft assembly comprises the head assembly of any one of claims 1-7, further comprising a drive head sandwiched between the first and second tangs, and a drive rod connected to the drive head, the hollow tube being connected to the base shoulder; the hollow tube is rigid or flexible and the drive rod is rigid or flexible.

9. A surgical instrument for minimally invasive surgery, which comprises the elongated shaft assembly of claim 8, and further comprises a handle assembly connected with the elongated shaft assembly, wherein the handle assembly comprises a first handle, a second handle and a handle rotating shaft, the first handle is connected with the hollow tube, the second handle is connected with a driving rod, the first handle and the second handle can rotate around the handle rotating shaft, so that the driving head is driven to do translational motion along the direction of the central shaft, and then the first cam pair is driven to generate relative sliding to force the first rotating pair to rotate mutually, and the second cam pair is driven to generate relative sliding to force the second rotating pair to rotate mutually, so that the first jaw head and the second jaw head can be rotated to open or close mutually.

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