Abstract:
An improved surgical apparatus actuator includes a nail bin assembly ( 1002 ), a nail anvil assembly ( 1001 ) connecting with the nail bin assembly ( 1002 ), and a drive assembly ( 1003 ) controlling the nail bin assembly ( 1002 ) and the nail anvil assembly ( 1001 ) to convert between opening and closing conditions. The nail anvil assembly ( 1001 ) includes a nail anvil plate ( 103 ) and a nail anvil seat ( 102 ), wherein the nail anvil plate ( 103 ) is provided on an inner side ( 1022 ) of the nail anvil seat ( 102 ), the nail anvil seat ( 102 ) has the structure, material and processing technology capable of providing high anti-bending performance, the nail anvil plate ( 103 ) is cold-punched from a thinner stainless steel sheet. Therefore, the processing difficulty of the components is reduced, and meanwhile, the ability of the actuator chuck to resist bending deformation is improved.

Description:
CROSS REFERENCE OF RELATED APPLICATION 
       [0001]    This is a U.S. National Stage under 35 U.S.C 371 of the International Application PCT/CN2013/082025, filed Aug. 22, 2013, which claims priority under 35 U.S.C. 119(a-d) to CN 201210349356.7, filed Sep. 18, 2012. 
     
    
     BACKGROUND OF THE PRESENT INVENTION 
       [0002]    1. Field of Invention 
         [0003]    This invention relates to a surgical apparatus, especially a kind of anastomat for surgical operation. More specifically, it relates to an improved surgical apparatus actuator. 
         [0004]    2. Description of Related Arts 
         [0005]    The working principle of surgical anastomat is to clamp tissues through the closing of two corresponding jaws (which are normally called nail anvil assembly and nail bin assembly) and then push the metal suturing nails in the anastomat nail bin out for molding and suture tissues together. In some anastomats, a cutter is installed to cut off sutured tissues. 
         [0006]    The anastomat with the above functions also includes actuator, intermediate connecting body and controller. The actuator consists of nail anvil assembly, nail bin assembly and drive assembly. The nail anvil assembly includes a nail molding surface which contains multiple rows of nail grooves. The nail groove is used for metal suturing nail molding. The nail bin assembly usually consists of nail bin, suturing nail, nail push block and nail push slide and nail bin seat. The upper surface of the nail bin is the tissue contact surface and the nail bin is installed in the nail bin seat. The nail anvil assembly connects at the near end with the near end of the nail bin assembly in a mobile manner and converts between the opening condition and closing condition. The drive assembly connects with the drive mechanism and is used to convert the triggering operation into actuator closing, triggering and opening operations. Generally, each of the nail anvil assembly and nail bin seat contains also a longitudinal groove. The above longitudinal groove is used to accommodate the drive assembly to allow it to pass. When the drive assembly moves toward the far end of the actuator through the above longitudinal groove, it drives the nail anvil assembly and nail bin assembly to convert from the opening condition to closing condition and drives the nail push slide and nail push block to push out suturing nails for molding in the nail groove of the nail molding surface of the nail anvil assembly. Generally, the drive assembly also includes a cutter, which is used to cut tissues among multiple rows of nail threads after tissues are sutured by suturing nails. The controller is used to control the apparatus operation manually, which usually consists of a fixed handle, a trigger connecting with the fixed handle in a relatively mobile manner and a group of drive mechanisms transmitting the triggering operation to the actuator. The intermediate connecting body connects with the far end of controller in a mobile manner and connects with the near end of the actuator. The intermediate connecting body constitutes a connecting passageway to transmit the triggering operation to the actuator. 
         [0007]    The Endo GIA Universal cutting anastomat from Tyco Healthcare in USA (renamed as Covidien later) and the Echelon cutting anastomat from Ethicon Endo-Surgery in USA are the representative products achieving the above functions. The above products have been sold for years and proved by market as having a good clinical application effect. The actuators of the blue nail bins of the above products can compress human body tissues (such as stomach tissues, lung tissues, intestine tissues, etc.) from a natural thickness of 5 mm-8 mm to a closing thickness of 1.5 mm when the nail anvil assembly and nail bin assembly close. In terms of the product function, the tissue closing thickness should be uniform from the near end of the nail anvil to the far end thereof so as to ensure suturing nails to be highly uniform in molding. Suturing effect can be guaranteed only when suturing nails suture tissues with a stable quality. Therefore, the nail anvil assembly needs to have a high bending strength. In nail anvil assembly manufacturing, the nail groove has a substantial material displacement in mould punching molding and this objectively requires that the material of the nail anvil assembly has good flowability and is easy to create a large-scale plastic deformation. The requirements of the nail anvil assembly for material plasticity and bending strength are contradictory. The technical proposals adopted by the Endo GIA Universal cutting anastomat and the Echelon cutting anastomat solve the above contradiction satisfactorily. However, there are still places requiring perfection, for example: the bending strength of the nail anvil assembly of the Endo GIA Universal cutting anastomat is still not high enough in some clinical applications and the processing technology is highly difficult; the bending strength of the Echelon cutting anastomat is enough, however, the processing technology is complicated with a high cost. 
         [0008]    For example, in U.S. Pat. No. 5,865,361, Tyco Healthcare described the nail anvil assembly of the Endo GIA Universal cutting anastomat. By referring to the description in U.S. Pat. No. 5,865,361 and combining with the design adopted for the real product being sold on market, the nail anvil assembly is welded from nail anvil plate and back cover plate. The empty cavity formed between the upper surface of the back cover plate and the nail anvil plate is the space for cutter holder pin to slide. The function of the back cover plate is to prevent tissues from being injured as a result of pinching by the cutter holder pin in the process of the nail anvil assembly closing tissues and anastomosing. The back cover plate is punched from 0.2 mm-0.3 mm thick stainless steel sheet. The nail anvil plate is punched from stainless steel sheet around 1 mm thick. Both the two spare parts use 304 stainless steel which can be strengthened through heat treatment and can exhibit a conspicuous machining hardening in the process of machining. On the lower surface of the nail anvil plate, a lot of nail grooves formed from cold punching process are distributed. For the Endo GIA Universal nail anvil plate with a 45 mm nail thread specification, 6 rows×11=66 nail grooves with a depth around 0.5 mm are punched (coldly) on the 45 mm×9 mm plane. The nail groove depth reaches half of the nail anvil plate material thickness. This results in the surface of material that the nail anvil plate and the mould punch top contact having serious machining hardening in nail groove cold punch molding, which prevents nail grooves from further molding and also results in aggravated wearing to the mould punch and mould life reduction and thus results in greater nail groove dimension fluctuation, accuracy reduction and eventual influence on the suturing nail molding quality. 
         [0009]    With regard to the above difficulties in nail groove molding, it is speculated that in manufacturing the nail anvil plate of the Endo GIA Universal cutting anastomat, the nail anvil plate uses 304 stainless steel sheet in annealed state to reduce maximally the initial material hardness, upgrade the nail groove molding accuracy and mould life. However, the bending strength of the nail anvil plate made of 304 stainless steel in annealed state is reduced and that thus results in the bending strength of the nail anvil assembly being low. As a result, when that product is applied to some thick tissue anastomosing and cutting occasions, the nail anvil assembly has a serious bending deformation after the nail anvil assembly and nail bin assembly close. As a result, it is unable to ensure the tissues clamped in the jaw to be consistent in compression thickness. Especially, the tissues at the far end of the jaw have an unsatisfactory closing effect due to incomplete compression. This results in tissues being easy to overflow toward the far end of the jaw in cutting and the tissue width after anastomosing being greater than the original tissue compression length. In some cases, it may result in having to increase the amount of nail bins, which implies the increase in medical cost; when serious, it may result in poor suturing nail molding. 
       SUMMARY OF THE PRESENT INVENTION 
       [0010]    With regard to the defects in the existing technology, the purpose of this invention is to provide an improved surgical apparatus actuator and an anastomat containing the actuator. According to the apparatus (i.e. anastomat) provided by this invention, tissue clamping can be achieved and the molding of at least one row of suturing nails can be achieved; in some application conditions, tissue cutting can also be achieved. Tissues can be cut open between multiple rows of suturing nail threads. 
         [0011]    According to one aspect of this invention, an improved surgical apparatus actuator is provided, including a nail bin assembly, a nail anvil assembly connecting with the nail bin assembly, and a drive assembly controlling the nail bin assembly and nail anvil assembly to convert opening and closing conditions. The nail anvil assembly includes a nail anvil plate and a nail anvil seat. The nail anvil plate is provided on an inner side face of the nail anvil seat. The nail anvil plate is cold-punched from stainless steel sheet. A thickness of the stainless steel sheet is lower than a maximum molding depth of nail grooves of the nail anvil plate. The nail anvil plate has a first guide groove provided thereon. The nail anvil seat has a second guide groove provided thereon. The first guide groove and the second guide groove are arranged coaxially. The drive assembly slides under a guide of the first guide groove and the second guide groove. 
         [0012]    Preferably, the nail anvil plate is punched and drawn from stainless steel sheet. 
         [0013]    Preferably, the thickness of the stainless steel sheet is 0.1-0.4 mm. 
         [0014]    Preferably, the thickness of the stainless steel sheet is 0.2-0.3 mm. 
         [0015]    Preferably, a tensile strength of a material used by the nail anvil seat is higher than that of the stainless steel sheet. 
         [0016]    Preferably, the nail anvil seat is processed by a method selected from a group consisting of thermal forging, powder metallurgical molding, casting and mechanical cutting. In which, the powder metallurgical molding process includes metal injection molding technology (MIM) and metal compression molding technology. 
         [0017]    Preferably, a back cover plate is also included, in which, the back cover plate is provided on an outer side face of the nail anvil seat. The outer side face of the nail anvil seat has a guide rail surface. An empty cavity exists between the back cover plate and the guide rail surface of the nail anvil seat. The drive assembly moves along the guide rail surface in the empty cavity. 
         [0018]    Preferably, all components of the nail anvil assembly are connected to form an integral structure through welding and/or mechanical riveting. 
         [0019]    Preferably, the nail grooves on the nail anvil plate are arranged in multiple rows of parallel straight lines or parallel curves selectively. 
         [0020]    Preferably, the nail grooves on the nail anvil plate are arranged into 4 rows or 6 rows. 
         [0021]    According to another aspect of this invention, an improved surgical apparatus is also provided, including a controller, an intermediate connecting body and an actuator, in which the actuator, the intermediate connecting body and the controller are connected in sequence. 
         [0022]    In comparison with the existing technology, this invention has the following beneficial effects: 
         [0023]    1. It mainly uses the nail anvil plate and nail anvil seat made of different materials to constitute the nail anvil assembly. As a result, the requirements of the nail anvil assembly for both material plasticity and bending strength are met. In which, the nail anvil plate uses thin stainless steel sheet for molding through tensile process to improve the difficulty in nail groove molding and provide nail grooves with a high accuracy; the nail anvil seat adopts a structural, material and processing proposal being able to provide a high bending strength to provide a strong bending property to the whole nail anvil assembly; 
         [0024]    2. The tensile strength of the material used by the nail anvil seat is higher than that of the material used by the nail anvil plate, which enables the nail anvil seat to provide a higher tensile strength and a higher bending strength that makes the nail anvil plate easier for molding through drawing. As a result, the problem of tissue overflow and poor suturing nail molding due to insufficient bending strength of the nail anvil assembly existing in the exist apparatus is overcome. 
         [0025]    3. The nail anvil assembly is combined by multiple components with different functions, which enhances the uniformity of the clamped tissues in thickness when the actuator closes tissues. In comparison with the existing product design proposals, the closing effect of the actuator is better, the manufacturing cost is lower and the clinical risk is smaller. 
         [0026]    4. When the thickness t of the stainless steel sheet for processing the nail anvil plate is less than the maximum molding depth h of nail groove, the cold punching process for processing the nail anvil plate can use punch drawing process in place of the impressing process used in nail groove molding on thick sheet. As a result, the nail groove dimension accuracy is increased. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]    By reading and referring to the detailed descriptions made by following figures to the unlimited embodiment, other characteristics, purposes and advantages of this invention will become more conspicuous: 
           [0028]      FIG. 1  is a structural schematic diagram of a surgical apparatus improved according to a first embodiment of this invention; 
           [0029]      FIG. 2  is an exploded structural schematic diagram for the surgical apparatus as shown in  FIG. 1 ; 
           [0030]      FIG. 3  is a partially enlarged structural schematic diagram for an actuator in the surgical apparatus as shown in  FIG. 1 ; 
           [0031]      FIG. 4  is a front structural schematic diagram for a nail anvil assembly in the surgical apparatus as shown in  FIG. 1 ; 
           [0032]      FIG. 5  is a schematic diagram for the three-dimensional structure of the nail anvil assembly in the surgical apparatus as shown in  FIG. 1 ; 
           [0033]      FIG. 6  is a structural schematic diagram for a nail anvil plate in the surgical apparatus as shown in  FIG. 1 ; 
           [0034]      FIG. 7  is a schematic diagram for a partially sectional structure at A-A in  FIG. 6  for the nail anvil plate in the surgical apparatus as shown in  FIG. 1 ; 
           [0035]      FIG. 8  is a structural schematic diagram for a nail anvil seat in the surgical apparatus as shown in  FIG. 1 ; 
           [0036]      FIG. 9  is a front structural schematic diagram for the nail anvil seat as shown in  FIG. 8 ; 
           [0037]      FIG. 10  is a sectional structure schematic diagram at B-B for the nail anvil seat as shown in  FIG. 9 ; 
           [0038]      FIG. 11  is a structural schematic diagram for a nail anvil seat in a surgical apparatus improved according to a second embodiment of this invention; 
           [0039]      FIG. 12  is a sectional structure schematic diagram at D-D for the nail anvil seat as shown in  FIG. 11 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0040]    A detailed description to this invention is to be made in combination with embodiments below. The following embodiment will help the technical people in this field to further understand this invention. However, it does not limit this invention in any form. What should be pointed out is that the ordinary technical people in this field can make a number of variations and improvements under the prerequisite not being divorced from the conception of this invention. All these belong to the protection scope of this invention. 
         [0041]    This invention applies to the actuator of surgical apparatus, uses a special spare part combination proposal, material combination proposal and processing technique proposal to manufacture the actuator to obtain a nail anvil assembly with a better comprehensive bending strength. 
         [0042]      FIG. 1  to  FIG. 10  show the schematic diagrams for the surgical apparatus improved according to the first embodiment of this invention. Specifically, in this embodiment, referring to  FIG. 1-FIG .  2 , the improved surgical apparatus includes a controller  300 , an intermediate connecting body  200  and an actuator  100 , in which the actuator  100 , the intermediate connecting body and the controller  300  are connected in sequence. 
         [0043]    The controller  300  usually includes a first fixed handle  301 , a second fixed handle  302 , a mobile trigger  303 , a trigger reset spring  310  and a drive and motion transfer mechanism transmitting a rotary motion of the trigger  303  to a drive rod  204  of the intermediate connecting body  200  and driving the drive rod  204  to make a straight line motion longitudinally. As shown in  FIG. 2 , the drive and motion transfer mechanism includes a pullout gear  313 , a pullout gear pin  311 , a pullout gear spring  312  and a rack  304 . The rack  304  can be installed in a reciprocating manner in a guide rail inside the first fixed handle  301  and the second fixed handle  302 . The pullout gear  313  can be installed in a rotary motion manner at one end of the trigger  303  through the pullout gear pin  311 . The pullout gear spring  312  keeps the pullout gear  313  deviating all the time for engagement with the rack  304 . When operating the trigger  303 , the rotary motion of the trigger  303  is transmitted to the rack  304  through the pullout gear  313  to drive the rack  304  to make a straight line motion toward a far end. Usually, the controller  300  also includes a set of rack reset mechanism to reset the rack  304  after completing an apparatus function. As shown in  FIG. 2 , the rack reset mechanism includes a first reset cap  305 , a second reset cap  306 , a reset pin  308 , a rack reset spring  309  and a pullout gear disengagement plate  307 . When the rack  304  is divorced from an initial position due to operating the trigger  303 , an operator pulls the first reset cap  305 , the second reset cap  306  toward a near end and drive the first pullout gear disengagement plate  307  to move through the reset pin  308  and bring along the pullout gear  313  to be divorced from a position engaging with the rack  304 ; when continuing to pull the first reset cap  305  and the second reset cap  306 , the reset pin  308  continues to draw back until the reset pin  308  and the rack  304  contact rigidly. When continuing to pull the first reset cap  305 , the second reset cap  306  toward the near end at this point, the rack  304  will move toward the near end with the reset pin  308  until reset. 
         [0044]    The intermediate connecting body  200  is connected at a far end of the controller  300 . In the surgical anastomat embodiment as shown in  FIG. 2 , the intermediate connecting body  200  includes: a first rotating joint  211 , a second rotating joint  212 , a drive rod  204 , a gun pipe  205 , a gun casing pipe  206 , a first nail box inner pipe  202 , a second nail box inner pipe  203 , a nail box casing pipe  201 , etc. An axis of the gun pipe  205 , the first nail box inner pipe  202  and the second nail box inner pipe  203  are co-axial and a direction of the axis constitutes the longitudinal direction of this embodiment. A near end of the gun pipe  205  is connected with the far end of the controller  300  through the first rotating joint  211 , the second rotating joint  212  in a mobile manner The drive rod  204  is arranged in inner cavities of the gun pipe  205  and the first nail box inner pipe  202 , the second nail box inner pipe  203 , and can make a free motion longitudinally in the inner cavities of the gun pipe  205  and the first nail box inner pipe  202 , the second nail box inner pipe  203 . The far end of the drive rod  204  connects with a near end of the drive assembly  109 . The near end of the drive rod  204  connects with the rack  304 . The drive rod  204  can transmit the longitudinal motion of the rack  304  to the drive assembly  109 . 
         [0045]    In the surgical anastomat embodiments as shown in  FIG. 2 , the intermediate connecting body  200  also includes a loading safety mechanism which can unload with the actuator  100 , including: a load reset spring  207 , a load safety block  208  and a load limit block  209 . After the actuator  100  and the intermediate connecting body are loaded together, the load safety block  208  prevents the actuator  100  and the intermediate connecting body  200  from making a relative rotation and unloading under an elastic force of the load reset spring  207 . 
         [0046]    Refer to  FIG. 2-FIG .  3 . The actuator  100  mainly consists of a nail anvil assembly  1001 , a nail bin assembly  1002  and a drive assembly  1003 . The nail bin assembly  1002  usually includes a nail bin  104 , multiple suturing nails  105 , multiple nail push blocks  106 , nail push slides  108  and a nail bin seat  107 . An upper surface of the nail bin  104  is a tissue contact surface. The nail bin  104  is installed in the nail bin seat  107 . The nail anvil assembly  1001  contains the nail anvil plate  103  and the nail anvil seat  102 . 
         [0047]    As shown in  FIG. 6-FIG .  7 , in this embodiment, the nail anvil plate  103  contains a first guide groove  1031  and multiple nail grooves  1032 . The drive assembly  1003  can make guided sliding in the first guide groove  1031 . The nail anvil plate  103  contains multiple rows of nail grooves  1032  on a surface toward clamping tissues. When the suturing nail  105  is driven to move toward the nail anvil plate  103 , the suturing nail  105  enters into the nail groove  1032  and is molded into B shape or similar B shape under the guide of the curved surface inside nail groove  1032 . 
         [0048]    In this embodiment, the nail anvil plate  103  is cold-punched from stainless steel sheet. A thickness t of the stainless steel sheet is lower than a maximum molding depth h of the nail groove  1032  of the nail anvil plate  103 , i.e. t&lt;h. In practical applications, for the suturing nail  105  with a diameter of 0.2 mm-0.25 mm, the maximum molding depth h of the nail groove  1032  is usually in a range of 0.4 mm-0.6 mm to ensure that sufficient guide property is provided during molding of the suturing nail  105 ; for the suturing nail  105  with a diameter of 0.25 mm-0.35 mm, the maximum molding depth h of nail groove  1032  is usually in a range of 0.45 mm-0.7 mm to ensure that sufficient guide property is provided during molding of the suturing nail  105 . When the thickness t of the stainless steel sheet for processing the nail anvil plate  103  is smaller than the maximum molding depth h of the nail groove  1032 , preferably, the cold punch process for processing the nail anvil plate  103  can use punch drawing process in place of the impressing process used in molding of the nail groove  1032  on a thick plate. 
         [0049]    Refer to  FIG. 4 ,  FIG. 8-FIG .  10 . The nail anvil seat  102  includes an inner side face  1022 , an outer side face  1023  and the second guide groove  1021 . The nail anvil plate  103  is arranged on an inner side face  1022  of the nail anvil seat  102 . The first guide groove  1031  of the nail anvil plate  103  and the second guide groove  1021  of the nail anvil seat  102  are arranged along a same axis Z. 
         [0050]    As shown in  FIG. 4 , the axis Z is a straight line. At this point, the nail grooves  1032  of the nail anvil plate  103  are arranged in multiple rows of parallel straight lines selectively. The number of the multiple rows of parallel straight lines includes 2 rows-8 rows and preferably 6 rows or 4 rows. In a variation of this embodiment, the difference from the embodiment shown in  FIG. 4  is that the axis Z is a curve in this variation. At this point, the nail grooves  1032  of the nail anvil plate  103  are arranged in multiple rows of curves selectively. The multiple rows of curves can be multiple concentric arcs and can also be multiple parallel asymptotes, which can also be curves of other types or a combinational curve of multiple types of curves. The number of the multiple rows of curves includes 2 rows-8 rows and preferably 6 rows or 4 rows. The selective arrangement into multiple rows means that the positions of the nail grooves  1032  are arranged in a staggered manner between the adjacent two rows of the nail grooves  1032 . 
         [0051]    To ensure that the nail anvil plate  103  and the nail anvil seat  102  are accurately positioned, as shown in  FIG. 4-FIG .  6 , a positioning hole  1033  is provided on the nail anvil plate  103  and the positioning pin  1024  is provided on the nail anvil seat  102 . The positioning hole  1033  on the nail anvil plate  103  and the positioning pin  1024  on the nail anvil seat  102  are matched for positioning. 
         [0052]    The nail anvil seat  102  is processed through a thermal forging process. In the variation of this embodiment, the nail anvil seat  102  can also be processed through a powder metallurgical molding process or a mechanical cutting process. 
         [0053]    The nail anvil assembly  1001  also includes a back cover plate  101 , which is arranged on an outer side face of the nail anvil seat  102 . 
         [0054]    In an optimum example of this embodiment, the assemblies of the nail anvil assembly can be connected into a whole through welding, mechanical riveting and a combination of both. In which, welding includes laser welding, resistance welding, fusion welding, etc. 
         [0055]    In another optimum example of this embodiment, the nail anvil plate  103  uses 304 stainless steel and nail anvil seat  102  uses 420 stainless steel. The 420 stainless steel can achieve a tensile strength not lower than 1300 MPa after an appropriate heat treatment process. Usually, the tensile strength of 304 stainless steel is not higher than that of 1050 MPa after H1/2 heat treatment. 
         [0056]      FIG. 11  and  FIG. 12  show the schematic diagram of the surgical apparatus improved according to the second embodiment of this invention. The technical people in this field can comprehend the second embodiment as shown in  FIG. 12  as a variation of the first embodiment as shown in  FIG. 1 . Specifically, the difference between this embodiment and the first embodiment as shown in  FIG. 1  is that in this embodiment, the back cover plate is omitted. More specifically, as shown in  FIG. 11-FIG .  12 , the nail anvil assembly  1001  contains the nail anvil plate  103  and the nail anvil seat  102  and does not include the back cover plate. The nail anvil seat  102  includes the inner side face  1022 , the outer side face  1023  and the second guide groove  1021 . The nail anvil plate  103  is arranged on the inner side face  1022  of the nail anvil seat  102 . The first guide groove  1031  of the nail anvil plate  103  and the second guide groove  1021  of the nail anvil seat  102  are arranged along the same axis Z. 
         [0057]    The above describes the embodiments of this invention. What need to understand is that this invention is not limited to the above specific embodiments. The technical people in this field can make different variations or modification within the scope of claims and this does not influence the essential contents of this invention.