CN110051410B - Slender shaft assembly capable of being detached, washed and reused and surgical instrument thereof - Google Patents

Abstract

The invention discloses a slender shaft assembly for detachable washing and reuse and a surgical instrument thereof, which comprise a base, a first jaw and a second jaw, wherein the first jaw and the second jaw are matched with the base; the first rotating pair and the second rotating pair can be disassembled, reassembled and sterilized for multiple times.

Description

Slender shaft assembly capable of being detached, washed and reused and surgical instrument thereof

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 factor (PHD) of University of Dundee, February 2017 summarizes in detail the unreliable and uncontrollable problems in the cleaning, distribution and use of the multiplexing apparatus, and thus no reliable solution exists up to now.

Disclosure of Invention

Therefore, in order to solve the problems of the prior art, an instrument which can be conveniently disassembled and washed is provided.

In one aspect of the invention, an elongated shaft assembly convenient to unpick and wash is provided, comprising a base and a first jaw and a second jaw matched 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 comprising a shoulder and a first fixing arm and a second fixing arm extending to distal ends, characterized in that the first jaw tail and the second jaw tail are sandwiched between the first fixing arm and the second fixing arm, the first jaw tail and the first fixing arm form a first revolute pair, and the second jaw tail and the second fixing arm form a second revolute pair; the first rotating pair and the second rotating pair can be repeatedly disassembled, reassembled and sterilized.

In one implementation, the first and second revolute pairs are under-constrained revolute pairs. More specifically, the first revolute pair comprises a first external cylindrical surface, a first internal cylindrical body and a first rotation axis, the first external cylindrical surface and the first internal cylindrical body comprising a rotational degree of freedom about the first rotation axis and a translational degree of freedom along the first rotation axis; the second revolute pair includes a second outer cylindrical surface, a second inner cylindrical body, and a second axis of rotation, the second outer cylindrical surface and the second inner cylindrical body including a rotational degree of freedom about the second axis of rotation and a translational degree of freedom along the second axis of rotation.

In another aspect, the first revolute pair comprises a first outer pair and a first inner pair, and the second revolute pair comprises a second outer pair and a second inner pair; the first outer pair comprises a partial cylindrical mounting surface and a cut-out feature, the first inner pair comprises a partial cylinder and a narrow body feature, the partial cylindrical mounting surface and the partial cylinder form a first rotating pair, and the first rotating pair can be disengaged when the first rotating pair is rotated to align the narrow body feature and the cut-out feature.

In another embodiment, the drive head is sandwiched between the first jaw tail and the second jaw tail, and comprises a drive block and a first lug and a second lug extending to the outside of the block, wherein the first lug and the first jaw tail form a first cam pair, and the second lug and the second jaw tail form a second cam pair; the driving block body can move in a translation mode along the axis of the slender shaft assembly, so that the first cam pair and the second cam pair are driven to slide, and the first rotating pair and the second rotating pair are driven to rotate.

In yet another aspect, the elongate shaft assembly includes an extreme state, a critical state, and an operating state, and satisfies the following relationship: le1 is more than Lu1, Lw1 is less than or equal to Le 1; lu1 is the driving head limit displacement, Le1 is the driving head critical displacement, and Lw1 is the driving head working displacement.

In yet another embodiment, the first jaw, the second jaw, the drive head and the base satisfy the following relationship: hj1+Hj2+ Hd1+ δ 1 —Hb 1; wherein 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.

In yet another embodiment, the first jaw, the second jaw, the drive head and the base satisfy the following relationship:hw1+ Hj2+ δ 2 —Hb 1; wherein, Hw1 is the thickness size of the first jaw wrist, Hj2 is the thickness of the second jaw tail,δ 2 is the processing error, and Hb1 is the distance between the first fixing arm and the second fixing arm of the base.

In another embodiment, the first jaw tail comprises an annular first driven groove, and the driving head comprises a first driving lug, the first driving lug and the first driven groove are matched to form a first cam pair, and the following geometrical relationship is satisfied: lj1 is more than or equal toLd 1; wherein Lj1 is the shortest distance between the geometric centroid of the far end of the first driven groove and the first secondary rotating axis along the buckling surface, and Ld1 is the shortest distance between the axial lead of the first driving lug and the central shaft.

In another implementation scheme, when the working opening angle Awork of the slender shaft assembly is greater than or equal to 0 degrees and less than or equal to 60 degrees, the first jaw wrist is always in contact with the second jaw tail, the second jaw wrist is always in contact with the first jaw tail, and the first jaw wrist and the second jaw wrist are designed to avoid the axial movement track of the driving head.

In one aspect of the invention, an inner core assembly convenient to clean is provided, which comprises a first jaw, a second jaw and a driving head matched with the first jaw, wherein the first jaw comprises a first jaw tail and a first jaw wrist connected with the first jaw tail, the second jaw comprises a second jaw tail and a second jaw wrist connected with the second jaw tail, and the driving head is clamped between the first jaw tail and the second jaw tail and forms a first cam pair with the first jaw tail and simultaneously forms a second cam pair with the second jaw tail.

In one scheme, the first jaw tail comprises a first driven groove, the second jaw tail comprises a second driven groove, the driving head comprises a driving block body and a first driving lug and a second driving lug which extend to the outside of the block body, the first driving lug and the first driven groove form a first cam pair, and the second driving lug and the second driven groove form a second cam pair.

In yet another aspect, the first drive lug and the first driven groove can slide relative to each other but cannot be completely disengaged, and the second drive lug and the second driven groove can slide relative to each other but cannot be completely disengaged.

In another embodiment, the first driving lug is integrally formed with the driving block, and the distal end of the first driving lug forms a deformation body under the action of an external force, and the size of the deformation body is larger than the width size of the driven groove matched with the deformation body, so that the first driving lug is prevented from being separated from the first driven groove.

In another aspect, the first driving lug is integrally formed with the driving block, and a distal end of the first driving lug includes a process recess, and an external force is applied to the process recess to form a deformation body, wherein the deformation body has a size larger than a width size of the driven groove matched with the deformation body, so that the first driving lug is prevented from being disengaged from the first driven groove.

In yet another version, the first tail includes a first driven slot therethrough, the second tail includes a second driven slot therethrough, and the drive head includes a drive block and first and second drive holes therethrough; first pin runs through in proper order first drive hole and first driven groove constitute first cam pair, first cam pair can produce relative slip but can not break away from completely, and the second pin runs through in proper order second drive hole and second driven groove constitute second cam pair, second cam pair can produce relative slip but can not break away from completely.

In yet another aspect, an elongate shaft assembly comprises any of the core assemblies described above, further comprising a static tube assembly comprising a base and a hollow tube connected thereto; 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 inner core assembly is clamped between the first fixing arm and the second fixing arm, wherein the first jaw and the first fixing arm form a first rotating pair, and the second jaw and the second fixing arm form a second rotating pair.

In a preferred scheme, the first rotating pair and the second rotating pair can be disassembled and reassembled for multiple times. In a specific scheme, the first rotating pair comprises a first outer side pair and a first inner side pair, and the second rotating pair comprises a second outer side pair and a second inner side pair; the first outer pair comprises a partial cylindrical mounting surface and a cut-out feature, the first inner pair comprises a partial cylinder and a narrow body feature, the partial cylindrical mounting surface and the partial cylinder form a first rotating pair, and the first rotating pair can be disengaged when the first rotating pair is rotated to align the narrow body feature and the cut-out feature.

In yet another aspect of the present invention, a surgical instrument for minimally invasive surgery is presented, the surgical instrument comprising any of the foregoing elongate shaft assemblies, and further comprising a handle assembly coupled thereto, the handle assembly comprising a handle shaft and first and second handles that rotate thereabout; the rotating wheel assembly and the button assembly connect the elongated shaft assembly and the handle assembly to form a quick release structure, the driving head further comprises a driving rod and a rod proximal end which are connected with the driving head, the rod proximal end is connected with the second handle, the first handle and the second handle rotate around the rotating shaft of the handle, so that the rod proximal end is pushed to move, the driving head is pushed to move, the first (second) cam pair is driven to slide relatively, and the first (second) jaw is forced to open or close around the first (second) rotating pair in a rotating manner.

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 thebase 30 a;

FIG. 4 is a side schematic view of thebase 30 b;

FIG. 5 is a cross-sectional view taken from 5-5 of FIG. 4;

FIG. 6 is a side schematic view of thebase 30 c;

FIG. 7 is a side schematic view of thebase 30 d;

FIG. 8 is a cross-sectional view of 8-8 of FIG. 7;

FIG. 9 is a side schematic view of thebase 30 e;

FIG. 10 is a distal-to-proximal projection view of thebase 30 e;

FIG. 11 is a distal-to-proximal projection view of thebase 30 f;

FIG. 12 is a cross-sectional view taken at 12-12 of FIG. 11;

FIG. 13 is a side schematic view of thebase 30 g;

FIG. 14 is a distal-to-proximal projection view of thebase 30 g;

FIG. 15 is a cross-sectional view of 15-15 of FIG. 13;

FIG. 16 is a side schematic view of the stillpipe assembly 4;

FIG. 17 is a side schematic view of themoving rod assembly 5;

FIG. 18 is a distal to proximal projection view of the moving rod assembly of FIG. 17;

FIG. 19 is a perspective view of thefirst jaw 10;

FIG. 20 is a perspective view of thesecond jaw 20;

FIG. 21 is an assembled schematic view of the head of theelongate shaft assembly 2;

FIG. 22 is a perspective view of the head of theelongate shaft assembly 2;

FIG. 23 is a side schematic view of the head of theelongate shaft assembly 2;

FIG. 24 is a perspective view of thesecond jaw 20 a;

FIG. 25 is an inside projection view of thefirst jaw 10b (second jaw 20 b);

FIG. 26 is a projection view of thefirst jaw 10b (thesecond jaw 20b) perpendicular to the occlusal surface;

FIG. 27 is a schematic view of a method of assembly of theelongate shaft assembly 2 b;

FIG. 28 is a partial side elevational view of the head of theelongate shaft assembly 2 b;

FIG. 29 is a partial perspective view (from a proximal to a distal perspective) of the head of theelongate shaft assembly 2 b;

FIG. 30 is a partial perspective view (from a distal to a proximal perspective) of the head of theelongate shaft assembly 2 b;

FIG. 31 is a schematic view of the drive head projection of themoving rod assembly 5 c;

FIG. 32 is a cross-sectional view taken at 32-32 of FIG. 31;

FIG. 33 is a perspective view of thefirst jaw 10c (second jaw 20 c);

FIG. 34 is an assembled schematic view of thefirst jaw 10c (thesecond jaw 20c) and the movingrod assembly 5 c;

FIG. 35 is a perspective view of thefirst jaw 10d (second jaw 20 d);

fig. 36 is a perspective view of thecore assembly 3 d;

fig. 37 is a schematic view of the maximum opening angle of thecore assembly 3 d;

fig. 38 is a small opening angle schematic view of thecore assembly 3 d;

FIG. 39 is a cross-sectional view 39-39 as depicted in FIG. 38;

FIG. 40 is an enlarged view of 40 from 39;

FIG. 41 is an alternative view of an enlarged view of 40 of FIG. 39;

FIG. 42 is a schematic rear view of theelongate shaft assembly 2;

FIG. 43 is a perspective schematic view of the handle assembly;

FIG. 44 is a partial cross-sectional view of the elongated shaft assembly mated with the handle assembly;

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.

A typicalendoscopic hand piece 1 comprises abase 30. Fig. 1-2 depict the structure and composition of the base 30 in detail. Thebase 30 comprises ashoulder 31 and afirst fixing arm 33 and asecond fixing arm 34 extending to the distal end, the first and second fixing arms forming a mountingspace 300 with adistance Hb 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, Hf1+ Hf2 <Hb 1.

In another 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.

In yet another example, the diameter Cd1 of theshaft hole 32, and the minimum distance L1 between thefirst boss 331 and thesecond boss 341, where Cd1 < L1.

Fig. 3 depicts yet anothersusceptor 30a of the present invention. The geometric structures in fig. 3 are numbered the same as the corresponding numbers in fig. 1-2, indicating that the structures with the same numbers are substantially identical. The same reference numerals in the different embodiments below indicate substantially identical structures. Thebase 30a is similar in construction to thebase 30, with the primary difference being the boss arrangement. Briefly, thebase 30a 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 of thebase 30a includes afirst boss 331a extending from the first mountingsurface 330 toward the firstmotion base surface 371; the distal end of thesecond fixing arm 34 of thebase 30a includes asecond boss 341a extending from the second mountingsurface 340 toward thefirst movement base 371. That is, thefirst boss 331a is substituted for thefirst boss 331 of thesusceptor 30, and thefirst boss 341a is substituted for thesecond boss 341 of thesusceptor 30, thereby constituting anew susceptor 30 a.

In one particular version, thefirst boss 331a includes a first stationarycylindrical portion 333a having a cross-sectional diameter Df1 and a firstnarrow body feature 334a having a cross-sectional width Bf1, where Bf1 <Df 1. In an alternative, the firstcylindrical fixing portion 333a comprises two oppositely arranged cylindrical surfaces, and the first narrow feature comprises two oppositely arranged tangential planes, but may also comprise only one tangential plane or a shaped cut-out surface, forming ashaped cylinder 331a (or referred to as ashaped prism 331a) comprising a partial cylinder and a partial narrow body. In one implementation, thesecond boss 341a includes a second stationarycylindrical portion 343a having a cross-sectional diameter Df2 and a secondnarrow body feature 344a having a cross-sectional width Bf2, where Bf2 <Df 2. In an alternative, the secondcylindrical fixing portion 343a comprises two oppositely disposed cylindrical surfaces, and the secondnarrow feature 344a comprises two oppositely disposed tangential planes, but may also comprise a tangential plane or a shaped cutaway surface, forming ashaped cylinder 341a (or ashaped prism 341a) comprising a partial cylinder and a partial narrow body.

In a preferred embodiment, thenarrow body feature 334a forms an included angle Ap1 with thefastening surface 372, and thenarrow body feature 344a forms an included angle Ap2 with thefastening surface 372, in a specific implementation, 0 ≦ Ap1 ≦ 45 °, and 0 ≦ Ap2 ≦ 45 °.

Fig. 4-5 depict yet another susceptor 30b of the present invention. Thebase 30b is similar in construction to thebase 30, with the primary difference being the boss arrangement. Briefly, thebase 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 of thebase 30b includes afirst fixing hole 331b recessed from the first mountingsurface 330 toward the inside of the fixing arm; the distal end of thesecond fixing arm 34 of thebase 30b includes asecond fixing hole 341b recessed from the second mountingsurface 340 toward the inside of the fixing arm. That is, thefirst boss 331 of thebase 30 is replaced with thefirst fixing hole 331b, and thesecond boss 341 of thebase 30 is replaced with thesecond fixing hole 341b, thereby constituting anew base 30 b.

Fig. 6 depicts yet another susceptor 30c of the present invention. Thebase 30c is similar in structure to thebase 30, and is mainly different in the arrangement of the fixing holes. Briefly, thebase 30c 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 of thebase 30c includes afirst fixing hole 331c recessed from the first mountingsurface 330 toward the inside of the fixing arm; the distal end of thesecond fixing arm 34 of thebase 30c includes asecond fixing hole 341c recessed from the second mountingsurface 340 toward the inside of the fixing arm. Thefirst fixing hole 331c includes a firstcylindrical surface 333c having a diameter Df3 and afirst notch 334c having a width Bf3, thenotch 334c cutting a portion of thefirst fixing hole 331c to form a half-open structure, Bf3 <Df 3. Thesecond fixing hole 341c includes a secondcylindrical surface 343c having a diameter Df4 and asecond slit 344c having a width Bf4, theslit 344c cutting a portion of thesecond fixing hole 341c to form a half-open structure, Bf4 <Df 4. That is, thefirst fixing hole 331b of thebase 30b is replaced with afirst fixing hole 331c having a cutout, and thesecond fixing hole 341b of thebase 30b is replaced with asecond fixing hole 341c having a cutout, thereby constituting anew base 30 c.

Fig. 7-8 depict yet anothersusceptor 30d of the present invention. Thebase 30d is similar in structure to thebase 30, and is mainly different in the arrangement of the fixing holes. 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 of thebase 30c includes afirst boss 331a extending from the first mountingsurface 330 toward the firstmovement base surface 371; the distal end of thesecond fixing arm 34 of thebase 30c includes asecond fixing hole 341b recessed from the second mountingsurface 340 toward the inside of the fixing arm. That is, thesecond bosses 341a of thebase 30a are replaced with the second fixingholes 341b, thereby constituting anew base 30 d.

Fig. 9-10 depict yet anothersusceptor 30e of the present invention. Thebase 30e is similar in structure to thebase 30, and is mainly different in the arrangement of the fixing holes. Briefly, thebase 30e 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 of thebase 30c includes afirst fixing hole 331c recessed from the first mountingsurface 330 toward the inside of the fixing arm; the distal end of thesecond fixing arm 34 of thebase 30c includes asecond boss 341 extending from the second mountingsurface 340 toward thefirst movement base 371. That is, thesecond boss 341 replaces thesecond fixing hole 341c of thebase 30c, thereby constituting anew base 30 e.

Fig. 11 to 12 depict anotherbase 30f of the present invention, thebase 30f has substantially the same structure as thebase 30d except that thefirst projection 331a and thesecond fixing hole 341b of the base 30 are respectively disposed on both sides of themovement base 371 and have symmetrical positional relationship (the axes of thefirst projection 331a and thesecond fixing hole 341b are coaxial).

Fig. 13-15 depict yet anotherpedestal 30g of the present invention, thepedestal 30g being similar in structure to thepedestal 30 a. Briefly, thebase 30c includes ashoulder 31, ashaft hole 32, afirst motion base 371, afirst fastening surface 372, afirst fixing arm 33, asecond fixing arm 34, afirst protrusion 331a and asecond protrusion 341 a. Thebase 30g further includes a first reinforcingarm 339g of height Hr1 extending from theshoulder 31 to adjacent thefirst projection 331a and integrally connected to thefirst retaining arm 33, and a second reinforcingarm 349g of height Hr2 extending from theshoulder 31 to adjacent thesecond projection 341a and integrally connected to thesecond retaining arm 34. The first and second reinforcing arms can improve the deformation rigidity of the first and second fixing arms to a large extent. In one embodiment, the first reinforcingarm 339g and the second reinforcingarm 349g are disposed on opposite sides of thefirst fastening surface 372 and are asymmetrical. In a specific scheme, Hr1 is not more than 0.5 Hb1, Hr2 is not more than 0.5 Hb1, and the arrangement can not only improve the deformation rigidity of the first fixing arm and the second fixing arm to a greater extent, but also simplify the manufacturing process of thebase 30g and greatly reduce the manufacturing cost of parts.

The base 30(30a,30b,30c,30D,30e,30f,30g) may be manufactured by a variety of methods, such as removing material from a metal bar (e.g., milling chips) or welding a plurality of parts together, or by 3D printing, or 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).

Figures 16-23 depict a typicalelongate shaft assembly 2. The elongated shaft assembly comprises astatic tube assembly 4, a movingrod assembly 5 and first andsecond jaws 10, 20 cooperating therewith.

Referring to fig. 16, astatic tube assembly 4 comprises thebase 30d and ahollow tube 40 connected thereto, thehollow tube 40 comprising a tubedistal end 41 and a tubeproximal end 49 and atube wall 45 extending therebetween, thetube wall 45 defining a central through-hole 46 substantially concentric with theaxial bore 32, the tubedistal end 41 being connected to theshoulder 31. It will be appreciated by those skilled in the art that the base and thehollow tube 40 may be attached by a variety of means including, but not limited to, welding, threading, gluing, and the like. Preferably,shoulder 31 is welded to tubedistal end 41 to form a seamless connection.

Referring to fig. 17-18, atravel rod assembly 5 includes adrive head 70 and adrive rod 80 connected thereto. Thedrive head 70 comprises a secondcentral axis 71, and a virtual firsttransverse plane 711 and a virtual firstlongitudinal plane 712 substantially perpendicularly intersect, the intersection line of which substantially coincides with the secondcentral axis 71. The first and second translation planes 74, 75 are substantially parallel to thelongitudinal plane 712 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. The geometric center offirst drive lug 740 is spaced fromcentral axis 71 by distance Ld1, the geometric center ofsecond drive lug 750 is spaced fromcentral axis 71 by distance Ld2, and Ld1 and Ld2 may be equal or different. 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, and the lug 740 (or lug 750) is located at the shortest distance Ldx1 from thedrive neck 72 in the axial direction.

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, the axis of thedrive rod 80 being substantially coincident with the secondcentral axis 71. Preferably, thedrive neck 72 is welded to thedistal rod end 81 to form a seamless connection.

Fig. 19 depicts the structure and composition of thefirst jaw 10. 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. Thefirst base hole 14 includes a firstcylindrical base surface 142 having a diameter Dr1 and afirst cutout 141 having a width Br1, thecutout 141 cutting away a portion of thecylindrical base surface 142 to form a semi-open structure. In an alternative, Br1 <Dr 1. Thefirst follower slot 15 includes a first follower slotproximal opening 151 having awidth dimension Ss 1. Thefirst follower groove 15 shown in fig. 25 does not extend through the firstlateral surface 11, but can extend completely through the chin-piece 13; thefirst base hole 14 shown in fig. 25 extends completely through thejaw tail 13 and may or may not extend through to the firstinner side 12.

Fig. 20 depicts the structure and composition of thesecond jaw 10. 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 pillar 24 is protruded from the secondouter side surface 21 to the outside of the jaw tail, and the second drivengroove 25 is recessed from the secondinner side surface 22 to the inside of thejaw tail 23. Thesecond wrist 26 is integrally connected to thesecond tail 23 and extends distally to form asecond jaw head 29.

The composition and assembled relationship of theelongate shaft assembly 2 is depicted with reference to fig. 21-23. The first andsecond tangs 13, 23 are sandwiched between the first and second retainingarms 33, 34 of thebase 30d, the first mountingsurface 330 mating with the firstouter side 11 and the second mountingsurface 340 mating with the secondouter side 21. Thefirst boss 331a is matched with thefirst base hole 14 to form a firstrotating pair 100; thesecond fixing hole 341b is matched with thesecond base cylinder 24 to form the secondrevolute pair 200. Thedrive head 70 is sandwiched between the first and second jaw tails with thefirst translation surface 74 mating with the 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 afirst cam pair 700; thesecond driving lug 750 is matched with the second drivengroove 25 to form a second cam set 800 (not shown). The drivinghead 70 is movable in translation in the axial direction, forcing thefirst driving lug 740 and the first drivenslot 15 into relative movement so as to drive thefirst jaw 10 in rotation about the firstrevolute pair 100; thesecond driving lug 750 and the second drivengroove 25 move relatively to each other to drive thesecond jaw 20 to rotate around the secondrevolute pair 200.

In yet another embodiment, the first jaw, the second jaw, the drive head and the base satisfy the following relationship:

Hj1+Hj2+Hd1+δ1＝Hb1；

wherein: 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 pitch of the first and second fixing arms, andδ 1 is the machining tolerance.

Referring now to fig. 21-23, in yet another embodiment, theelongated shaft assembly 2 includes three states, an extreme state, a critical state and an operating state, and thedriver head 70 includes three states, namely, an extreme displacement Lu1, a critical displacement Le1 and an operating displacement Lw1 (displacement measurement: shortest distance of thefirst drive lug 740 from thefirst boss 331a in the axial direction).

Extreme displacement Lu 1: when the drive head is at its extreme displacement, thefirst jaws 10 can be rotated about the firstrevolute pair 100 so that the first cam pairs 700 disengage from each other. That is, thefirst jaw 10 can be rotated about the first pair of rotation to completely disengage thefirst drive lug 740 from the first drivenslot 15, while the jaw tail is shaped and dimensioned so that it does not interfere with thedrive neck 72 during rotation, which is said to be the limit condition.

Critical displacement Le 1: when the driving head is in the extreme displacement, thefirst cam pair 700 is in the critical state, and in this critical state, when the drivinghead 70 is moved from the proximal end to the distal end, thefirst cam pair 700 is disengaged from each other (thelug 740 is completely disengaged from the driven groove 15), i.e. the first cam pair is converted into the extreme state; when the drivinghead 70 is moved from the distal end to the proximal end, the first cam set 700 is always in contact (thelug 740 and thefollower groove 15 cooperate to form the first cam set), i.e., the working state is changed.

Working displacement Lw 1: when the driving head is in working displacement, the first rotating pair and the first cam pair are always kept in contact, and in a working state, when the drivinghead 70 is moved from the proximal end to the distal end, thefirst cam pair 700 slides relatively, so that thefirst jaws 10 are pushed to rotate around the first rotating pair to open or close, Lw1 <Le 1.

Theslender shaft assembly 2 can be quickly disassembled and assembled, and fine pin shafts or other fine scattered parts do not need to be assembled or disassembled in the assembling and disassembling process, so that the assembling and disassembling efficiency can be greatly improved, and the assembling cost and the rejection rate of finished products are greatly reduced. The assembly method is that, in brief, the drivinghead 70 is firstly placed in thebase 30d, thesecond jaw 20 is firstly placed in the base, thesecond driving lug 750 is adjusted to match with the second drivengroove 25 to form the second cam pair 800, and thesecond fixing hole 341b is adjusted to match with thesecond base column 24 to form the secondrevolute pair 200; the drive head is then placed into the extreme displacement Lu1, the firstnarrow body feature 334a is inserted in alignment with thefirst notch 141, rotated to mate the first stationarycylindrical portion 333a with the firstcylindrical base surface 142 to form the firstrevolute pair 100, and finally thefirst jaw 10 is rotated and thedrive head 70 is moved to cause thefirst drive lug 740 to enter the first drivenslot 15 through the first driven slotproximal opening 151 and mate therewith to form thefirst cam pair 700. The method of disassembly of theelongated shaft assembly 2 is the reverse of the assembly method described above and will be readily understood by those skilled in the art in view of the text and will not be described in detail. An additional limiting mechanism can be added, so that theinstrument 1 can limit the displacement of the drivinghead 70 to a working displacement Lw1 which is less than or equal to Le1 in the using process, and the working jaw can be effectively prevented from being separated out in the using process. In the simplest case, thehollow tube 40 and thedrive rod 80 are reasonably arranged in length, so that when theelongate shaft assembly 2 and the handle assembly are assembled into a whole, the limit of the handle assembly ensures that Lw1 is not less thanLe 1. Other stop mechanisms are also conceivable to those skilled in the art, having the idea of the invention.

Yet another elongated shaft assembly 2a (not shown) includes abase 30e, adrive head 70, a first jaw 10a, and asecond jaw 20 a. Fig. 24 depicts a furthersecond jaw 20a, whichsecond jaw 20a is structurally similar to thesecond jaw 20, differing only in the provision of a base pillar and a driven slot, and in brief thesecond tail 23 of thesecond jaw 20a comprises asecond base pillar 24a extending from the secondouter side 21 outwardly of the tail and a second drivenslot 25a recessed from the secondinner side 22 inwardly of the tail. Thesecond base pillar 24a includes a secondcylindrical base 242a having a diameter Dr4 and a secondnarrow body feature 241a having a width Br4, Br4 <Dr 4. Thesecond follower slot 25a includes a second follower slotproximal opening 251 a. A further first jaw 10a (not shown in the figures) is similar to thefirst jaw 10, differing only in the arrangement of the base hole and the driven slot, in brief the first base hole 14a of the first jaw 10a does not comprise a first incision, the first driven slot 15a of the first jaw 10a does not comprise a driven slot proximal opening.

The elongate shaft assembly 2a also includes an extreme condition, a critical condition and an operative condition. The assembly and disassembly process does not need to install or disassemble tiny pin shafts or other tiny scattered parts. Briefly, the drivinghead 70 is first placed in thebase 30e, thefirst jaw 10 is first installed, and thefirst driving lug 740 is adjusted to match the first driven groove 15a to form the first cam pair 700a and thefirst boss 331 is adjusted to match the first base hole 14a to form the first rotating pair 100 a; the drive head is then placed in extreme displacement, the secondnarrow body feature 241a is inserted in alignment with thesecond cutout 344c, rotated to mate the secondcylindrical base 242a with the secondcylindrical surface 343c to form the second revolute pair 200a, and finally thesecond jaw 20 is rotated and thedrive head 70 is moved to cause thesecond drive lug 750 to enter the second drivenslot 25 through the second driven slotproximal opening 251a and mate therewith to form the second cam pair 800 a. The method of disassembly of the elongate shaft assembly 2a is the reverse of the assembly method described above and will be readily understood by those skilled in the art in conjunction with the drawings and will not be described in detail.

Fig. 25-30 depict yet anotherelongate shaft assembly 2b of the present invention. Theelongated shaft assembly 2b includes afirst jaw 10b, asecond jaw 20b, astatic tube assembly 4b and an movingrod assembly 5. Thestationary tube assembly 4b includes abase 30a and ahollow tube 40 attached thereto, preferably with ashoulder 31 welded to adistal tube end 41 to form a seamless connection.

Fig. 25-26 depict in detail the structure and composition of thefirst jaw 10b and thesecond jaw 20 b. Thefirst jaw 10b (second jaw 20b) is similar to the first jaw 10 (second jaw 20) and mainly differs in the arrangement of the jaw wrist, the base hole and the driven groove. Briefly, thefirst jaw 10b includes a firstouter side 11, a firstinner side 12, afirst jaw tail 13, afirst jaw wrist 16, and afirst jaw head 19. Thefirst base hole 14b is recessed from the firstouter side surface 11 toward the inside of thejaw tail 13, and the first drivengroove 15b is recessed from the firstinner side surface 12 toward the inside of thejaw tail 13. Thefirst base hole 14b includes a firstcylindrical base surface 142b having a diameter Dr1 and afirst cutout 141b having a width Br1, thecutout 141b cutting a portion of thecylindrical base surface 142b to form a semi-open structure. Thefirst follower slot 15b includes a first follower slotdistal end 159b and generally parallel slot sides extending from the slot distal end to a first follower slotproximal end 151 b. Theproximal groove end 151b, the groove sides and thedistal groove end 159b form a closed race-track type annular groove. Although the groove sides are shown as straight surfaces, curved surfaces are also possible. Thefirst jaw arm 16b comprises afirst support surface 17 b.

Thesecond jaw 20b includes a secondouter side 21, a secondinner side 22, asecond jaw tail 23, asecond jaw wrist 26, and asecond jaw head 29. Thesecond base hole 24b is recessed inwardly of thejaw tail 23 from the secondouter side surface 21, and thesecond follower groove 25b is recessed inwardly of thejaw tail 23 from the secondinner side surface 22. Thesecond base hole 24b includes a secondcylindrical base surface 242b having a diameter Dr2 and asecond cutout 241b having a width Br2, thecutout 241b cutting a portion of thecylindrical base surface 242b to form a half-open structure. The second drivenslot 25b includes a second driven slotdistal end 259b and generally parallel slot sides extending from the slot distal end to the second driven slotproximal end 251 b. Theproximal end 251b, sides anddistal end 259b of the groove form a closed race-track type annular groove. Thesecond jaw arm 26b includes asecond bearing surface 27 b.

Referring now to fig. 27-30, thefirst jaw 10b, thesecond jaw 20b are sandwiched between afirst securing arm 33 and asecond securing arm 34 of the base 30 g; the firstouter side 11 is matched with the first mountingsurface 330, the secondouter side 21 is matched with the second mountingsurface 340, the first supportingsurface 17b is matched with the secondinner side 22, and the second supportingsurface 27b is matched with the firstinner side 12; thefirst boss 331a and thefirst base hole 14b constitute a firstrevolute pair 100b, and thesecond boss 341a and thesecond base hole 24b constitute a second revolute pair 200 b.

Thedrive head 70 is clamped between thefirst jaw tail 13b and thesecond jaw tail 23b, between the firstinner side 12 and the secondinner side 22, and the first drivenchute 15b and thefirst drive lug 740 form afirst cam pair 700 b; the second drivenchute 25b and thesecond driving lug 750 constitute a second cam set 800 b. The movement and drive relationship will be readily understood by those skilled in the art in conjunction with the foregoing. In brief, when the drivinghead 70 moves along the axis, thefirst cam pair 700b slides relatively, causing thefirst jaw 10b to open or close rotationally about the firstrevolute pair 100 b. The interaction between thedrive head 70 and thesecond jaw 20b is similar and will not be described in detail.

Theslender shaft assembly 2b can be quickly disassembled and assembled, and fine pin shafts or other fine scattered parts do not need to be assembled or disassembled in the assembling and disassembling process. The assembling method and the steps of theslender shaft component 2b are as follows:

s1, the first jaw, the second jaw and the movingrod component 5 are matched: inserting thefirst drive lug 740 into the first drivenslot 15b to form afirst cam set 700b and thesecond drive lug 750 into the second drivenslot 25b to form asecond cam set 800b, and rotating the first and second jaws to match thefirst translation surface 74 to the firstinner side 12 and thesecond translation surface 75 to the secondinner side 22;

s2, matching with the base: loading the assembled components from step S1 into abase 30g together by first mating the firstouter side 11 with the first mountingsurface 330 and the secondouter side 21 with the second mountingsurface 340 and aligning the firstnarrow body feature 334a with thefirst cutout 141b and the secondnarrow body feature 344a with thesecond cutout 241 b; the first and second jaws are then translated and rotated such that the firstcylindrical base surface 142b mates with the first stationarycylindrical portion 333a to form a firstrevolute pair 100b and the secondcylindrical base surface 242b mates with the second stationarycylindrical portion 343a to form a second revolute pair 200b (as understood with reference to fig. 27-30).

In one specific embodiment, the shortest distance between the geometric centroid of the slotproximal end 151b and the center of thefirst base hole 14b along the snap plane is Lj1, where Lj1 >Ld 1. Similarly, in theelongate shaft assembly 2b, thedrive head 70 includes three states, an extreme state, a critical state and an operating state, and thedrive head 70 includes an extreme displacement Lu2 (when the firstnarrow body feature 334a is completely disengaged from thefirst notch 141 b), a critical displacement Le2 (when the firstnarrow body feature 334a is aligned with thefirst notch 141 b) and an operating displacement Lw2 (when the firstcylindrical base surface 142b is mated with the first stationarycylindrical portion 333 a) to form the firstrevolute pair 100 b).

With continued reference to fig. 27-30, in yet another particular version, the dimensions of thefirst jaw wrist 16b satisfy the following relationship: hw1+ Hj2+ δ 2 ═ Hb1, where: hw1 is the thickness dimension of thefirst jaw arm 16b, Hj2 is the thickness of thesecond jaw tail 23b,δ 2 is the machining tolerance, and Hb1 is the distance between the first and second fixing arms of the base.

With continued reference to fig. 27-30, in yet another particular version, the dimensions of thesecond jaw arm 26b satisfy the following relationship: hw2+ Hj1+ δ 3 ═ Hb1, where: hw2 is the thickness dimension of thesecond jaw arm 26b, Hj1 is the thickness of thefirst jaw tail 13b, δ is the machining tolerance, and Hb1 is the distance between the first and second fixing arms of the base.

Referring now to FIGS. 27-30, in yet another specific embodiment, theelongate shaft assembly 2b has an operative opening angle Awork, typically 0 deg. or greater Awork or less 80 deg., and thefirst wrist 16b (first wrist 26b) is contoured such that thefirst support surface 17b is in constant contact with the secondinner side surface 22 and thesecond support surface 27b is in constant contact with the firstinner side surface 12 over the operative opening angle Awork of theelongate shaft assembly 2 b. Thefirst jaw arm 16b (the second jaw arm 26) is configured to avoid the axial movement track of the drivinghead 70 in the working state and the extreme state, i.e. thefirst jaw arm 16b (the second jaw arm 26) and the drivinghead 70 do not interfere with each other during the assembling, working and disassembling process of theelongated shaft assembly 2 b.

FIGS. 31-32 depict a modified movingrod assembly 5 c. The movingrod assembly 5c is similar in structure and composition to the movingrod assembly 5. The main difference is the provision of the drive neck. In brief, the drivingneck 72c includes afirst positioning block 721 and asecond positioning block 726. In one embodiment, thefirst positioning block 721 includes alateral positioning surface 722 and anaxial positioning surface 723, and thesecond positioning block 726 includes alateral positioning surface 727 and anaxial positioning surface 728.

Fig. 33 depicts a modifiedfirst jaw 10c (second jaw 20c) comprising afirst jaw tail 13c (second jaw tail 23c), thefirst jaw tail 13c comprising a first jawtail positioning portion 133c matching the shape and size of afirst positioning block 721, thesecond jaw tail 23c comprising a second jawtail positioning portion 233c matching the shape and size of asecond positioning block 726.

An improved elongated shaft assembly 2c includes afirst jaw 10c, asecond jaw 20c, astatic tube assembly 4b (not shown), and a movingrod assembly 5 c. Fig. 34 depicts the assembly process of the elongated shaft assembly 2c, in brief: the first jaw 10c, the second jaw 20c and the moving rod assembly 5c are matched, the first driving lug 740 is inserted into the first driven groove 15b to form a first cam pair 700b, the second driving lug 750 is inserted into the second driven groove 25b to form a second cam pair 800b, the first jaw and the second jaw are rotated to enable the first translation surface 74 to be matched with the first inner side surface 12, the second translation surface 75 to be matched with the second inner side surface 22, the first jaw tail positioning part 133c to be matched with the first positioning block 721, and the second jaw tail positioning part 233c to be matched with the second positioning block 726; then keeping the three matching states, and then putting the three into the base together, firstly matching the first outer side 11 with the first mounting surface 330 and the second outer side 21 with the second mounting surface 340, and aligning the first narrow body feature 334a with the first notch 141b, and aligning the second narrow body feature 344a with the second notch 241 b; finally, the first and second jaws are translated and rotated, so that the first cylindrical base surface 142b is matched with the first fixed cylindrical portion 333a to form the first revolute pair 100b, and the second cylindrical base surface 242b is matched with the second fixed cylindrical portion 343a to form the second revolute pair 200b, thereby completing the assembly.

The arrangement of the first positioning block 721 (the second positioning block 726) provides sufficient pre-fixing, which can greatly improve the assembly efficiency and reduce the assembly skill requirement. Studies have shown that with the proper positioning mechanism, the removal and reassembly of the elongated shaft assembly can be accomplished without difficulty and proficiency by simple training of ordinary workers or customers (medical personnel). Although the positioning block is depicted in the figures as having a profile in which the transverse and axial positioning surfaces are at right angles, one of ordinary skill could readily adapt other shapes without departing from the spirit of the present invention. The first positioning block 721 (the second positioning block 726) also has a function of enhancing the strength of the driving neck.

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.

The reusable endoscope hand-held instrument can be generally disassembled into a handle and an elongated shaft assembly, and the handle and the elongated shaft assembly are disassembled, cleaned, reassembled and sterilized for reuse. The sterilization mode is usually high-temperature moist heat sterilization or low-temperature plasma sterilization, however, whatever sterilization mode is adopted, the used instruments must be thoroughly cleaned firstly, and then the instruments can be sterilized according to the corresponding sterilization procedures and then can be used for operation again. In the operation, the head of the instrument needs to operate the internal tissues of a patient, and the moving joint of the head instrument is easy to leave tissue residues and difficult to clean. To address this difficulty, the prior art discloses disassembling the elongated shaft assembly into 2-parts, 3-parts. However, to date, the prior art and commercially available reusable endoscopic hand held instruments have been disclosed which have a head with a first jaw, a second jaw and a base that are not detachable from one another. This results in the revolutionary joints between the first jaw, the second jaw and the base being prone to residual diseased tissue or bacterial virus, being extremely difficult to clean, making the sterilization process unreliable and risking cross-contamination.

In connection with the foregoing, one of the ideas of the present invention should be readily understood by a person skilled in the art, namely that the first and second tangs are sandwiched between the first and second fixed arms, the first tang constituting with the first fixed arm a first revolute pair and the second tang constituting with the second fixed arm a second revolute pair, said first revolute pair and second revolute pair being repeatedly detachable and reattachable. In one implementation, the repeated disassembly and reassembly depicted herein is free-hand disassembly and reassembly without the need for additional tools for ease of client application.

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.

In a specific embodiment, the first outer cylindrical surface comprises a cylindrical stationary surface and a cut-out feature, and the first inner cylindrical surface comprises a partial cylinder and a narrow body feature, the partial cylindrical stationary surface and the partial cylinder forming a first rotating pair that can be disengaged when the first rotating pair is rotated into alignment with the narrow body feature and the cut-out feature.

In yet another aspect of the present invention, acore assembly 3d is presented, thecore assembly 3d comprising afirst jaw 10d, asecond jaw 20d and a movingrod assembly 5 c.

As shown in FIG. 35, thefirst jaw 10d (second jaw 20d) is substantially identical in structure and composition to thefirst jaw 10c (second jaw 20c) described above. Thefirst follower slot 15d includes a first follower slot distal end 159d and generally parallel slot sides extending from the slot distal end to the first follower slotproximal end 151 d. Theproximal groove end 151d, the groove sides and the distal groove end 159d form a closed race-track type annular groove. The first drivengroove 15d transversely penetrates the first jaw tail. The second drivenslot 25d includes a second driven slot distal end 259d and generally parallel slot sides extending from the slot distal end to the second driven slotproximal end 251 d. Theproximal groove end 251d, the groove sides and the distal groove end 259d form a closed race-track type annular groove. The second drivengroove 25d transversely penetrates the second jaw tail. That is, the drivengroove 15b (25b) originally existing in thefirst jaw 10c (thesecond jaw 20c) and not penetrating the jaw tail is replaced with a driven groove penetrating the jaw tail, and a newfirst jaw 10d (thesecond jaw 20d) is formed.

The composition and assembly of thecore assembly 3d is depicted in fig. 36-37: thedrive block 73 of the movingrod assembly 5c is sandwiched between thefirst tang 13b of thefirst jaw 10d and thesecond tang 23b of thesecond jaw 20d, thefirst drive lug 740 being inserted into the first drivenslot 15d to form thefirst cam set 700d, and thesecond drive lug 750 being inserted into the second drivenslot 25d to form the second cam set 800 d. In one embodiment, thefirst cam pair 700d (thesecond cam pair 800d) of thecore assembly 3d is not detachable under the normal condition, i.e., thefirst lug 740 can slide in the first drivengroove 15d but cannot completely disengage from the first drivengroove 15d (thesecond lug 750 can slide in the second drivengroove 15d but cannot completely disengage from the second drivengroove 25 d). The technical scheme for realizing that the first cam pair (the second cam pair) can slide mutually and can not be separated is more. As shown in fig. 38 to 40, in one embodiment, an external force such as pressing, knocking or the like is applied to the distal end of thefirst driving lug 740 to generate adeformation body 741, and thedeformation body 741 has a size larger than the width of the driven groove to be matched therewith, so as to prevent the first driving lug from falling off the first driven groove. Preferably, the first drivengroove 15d further includes a notch chamfer (or notch recess) 158d to accommodate thedeformation body 741. In yet another alternative embodiment shown in FIG. 41, the distal end of thefirst driving lug 740 includes arecess 742e, which is pressed and peened to generate adeformation 741e, wherein thedeformation 741e is larger than the width of the driven slot to prevent the first driving lug from falling out of the first driven slot. In a matching manner, the first driven groove includes a sinkinggroove 158e or a position-avoidingregion 158 e.

In a further alternative (not shown), thefirst drive lug 740 is replaced by a first drive hole 740f, thesecond drive lug 750 is replaced by a second drive hole 750f, and thefirst follower slot 15d is riveted to thedrive block 73 by an additional pin to form a first cam set, the rivet pin being slidable between the first follower slots but not completely disengaged therefrom. Similarly, thesecond follower groove 25d is riveted to thedrive block 73 by an additional pin to form a second cam set, the riveting pin being slidable between the second follower grooves but not completely disengaged therefrom.

In yet another aspect of the invention, an elongate shaft assembly 2d is provided that includes the aforementionedinner core assembly 3d and astatic tube assembly 4 b. The method of assembling and disassembling the elongated shaft assembly 2d will be readily understood with reference to FIGS. 27, 34 and 37, and with the foregoing description. Briefly, after theinner core assembly 3d is assembled, the first jaw and the second jaw are rotated to match the jaw tail positioning portion with the positioning block, the jaw tail positioning portion and the positioning block are placed into thebase 30a together, the narrow body feature and the cut are aligned, the moving rod assembly is moved to work displacement, the first rotating pair and the second rotating pair are formed, and the assembly of the slender shaft assembly 2d is completed. When the displacement of the reversely moving rod assembly exceeds the limit displacement, the first rotating pair and the second rotating pair mutually fall off, so that the elongated shaft assembly 2d is disassembled into theinner core assembly 3d and thestatic pipe assembly 4b, and the two parts are easy to clean. Compared with the reusable slender shaft assembly disclosed by the prior art, the slender shaft assembly disclosed by the invention is more convenient to disassemble and assemble, and has no dead angle in cleaning.

In another design, as shown in fig. 42, thestationary tube assembly 4b further includes an insulatingtube 451 covering the outside of thehollow tube 40, and aconnector 455 fixed to the end of the insulating tube, and theproximal end 49 of thehollow tube 40 further includes a limitinggroove 48.

In yet another aspect of the invention, areusable handle assembly 9 is provided, as shown in fig. 43-44. The handle assembly includes afirst handle 91 and asecond handle 92 connected by ahandle pivot 91, the first and second handles being rotatable about the handle pivot. Thewheel assembly 95 includes awheel 951, anouter sleeve 953, and aninner sleeve 955, theouter sleeve 953 integrally connected to thewheel 951, theinner sleeve 955 integrally connected to thefirst shaft 91, and theouter sleeve 953 and theinner sleeve 955 forming a third revolute pair for allowing thewheel 951 to rotate relative to the first shaft. Abutton assembly 97 is mounted inbutton mounting compartment 98 offirst handle 91. Thebutton assembly 97 includes alock 972 connected at one end to aresilient member 971 and at the other end to abutton 974, afastener 973 restraining thelock 972 within the mountingchamber 98, theresilient member 971 driving thelock 972 laterally within the mountingchamber 98 to a locked position.

Referring to fig. 42-44, in another aspect of the invention, a hand-heldinstrument 1 for minimally invasive surgery is provided comprising the previously describedelongated shaft assembly 2 and handleassembly 9, wherein theproximal rod end 89 mates with thesecond handle 93, theresilient member 971 drives thelock 972 laterally within the mountingcartridge 98 to a locked position and mates with the retaininggroove 48, and thecoupling head 455 mates with therunner 951 and transmits rotational torque from the runner to the elongated shaft assembly. The first and second handles rotate about the handle rotation axis, thereby pushing the rodproximal end 89 to move axially, further pushing the driving head to move axially, further driving the first (second) cam pair to slide relatively, and further forcing the first (second) jaw to open or close rotationally about the first (second) revolute pair.

Depressing thebutton 97 compresses theresilient member 971 to move thelock 972 laterally away from the locked position, disengaging the retaininggroove 48 from thelock 972, thereby separating theelongated shaft assembly 2 from thehandle assembly 9, as previously described, and thereby separating the first (second) jaw from the static tube assembly, thereby facilitating the cleaning of the elongated shaft assembly without dead angles.

US patents US5489290, US5947996, US6340365, US7931667, US8551077, US8926599 and the like disclose various quick connect and disconnect mechanisms of the elongate shaft assembly to the reusable handle, which mechanisms, with slight adaptations, may be used for the connection between the elongate shaft assembly and the reusable handle of the present invention. The field of minimally invasive surgical instruments has disclosed so far many ways of connecting the elongated shaft assembly and the handle of the minimally invasive surgical instrument, and the connection of the elongated shaft assembly and the handle of the minimally invasive surgical instrument can be used with slight adaptation, and is not exhaustive here. 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 (4)

1. An elongated shaft assembly comprises a base, a first jaw and a second jaw, wherein the first jaw and the second jaw are matched with the base, the first jaw comprises a first jaw tail and a first jaw wrist connected with the first jaw tail, the second jaw comprises a second jaw tail and a second jaw wrist connected with the second jaw tail, 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 far ends, and the elongated shaft assembly is characterized in that 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, and the second jaw tail and the second fixing arm form a second rotating pair; the first rotating pair and the second rotating pair can be disassembled, reassembled and sterilized for many times;

the first rotating pair and the second rotating pair are under-constrained rotating pairs;

the driving head comprises a driving block body, a first lug and a second lug, wherein the first lug and the second lug extend to the outside of the block body, the first lug and the first jaw tail form a first cam pair, and the second lug and the second jaw tail form a second cam pair; the driving block body can move in a translation mode along the axis of the slender shaft assembly, so that the first cam pair and the second cam pair are driven to slide, and the first rotating pair and the second rotating pair are driven to rotate;

the elongate shaft assembly includes an extreme condition, a critical condition, and an operating condition, and satisfies the following relationship:

Le1＜Lu1，Lw1≤Le1；

lu1 is the driving head limit displacement;

le1 is the critical displacement of the driving head;

lw1 is the drive head working displacement.

2. The elongate shaft assembly of claim 1, the first revolute pair comprising a first outside pair and a first inside pair, the second revolute pair comprising a second outside pair and a second inside pair; the first outer pair comprises a partial cylindrical mounting surface and a cut-out feature, the first inner pair comprises a partial cylinder and a narrow body feature, the partial cylindrical mounting surface and the partial cylinder form a first rotating pair, and the first rotating pair can be disengaged when the first rotating pair is rotated to align the narrow body feature and the cut-out feature.

3. The elongate shaft assembly as recited in claim 1, wherein the first jaw, the second jaw, the drive head and the base satisfy the following relationship:

Hj1+ Hj2+ Hd1+δ1＝Hb1；

wherein 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.

4. A surgical instrument for minimally invasive surgery, the surgical instrument comprising the elongate shaft assembly of any one of claims 1-3, further comprising a handle assembly mated thereto, the handle assembly comprising a handle shaft and first and second handles that rotate thereabout; the rotating wheel assembly and the button assembly connect the elongated shaft assembly and the handle assembly to form a quick release structure, the driving head further comprises a driving rod and a rod proximal end which are connected with the driving head, the rod proximal end is connected with the second handle, the first handle and the second handle rotate around the handle rotating shaft, so that the rod proximal end is pushed to move, the driving head is pushed to move along the axis, the first cam and the second cam are driven to slide relatively, and the first jaw, the second jaw and the first revolute pair are forced to open or close in a rotating mode.

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