Abstract:
A mounting assembly for mounting a surgical instrument to a base, which facilitates positioning a surgical instrument relative to the surgical site so that only the minimum portion of the instrument is positioned in the free space available around the surgical site. A surgical instrument is also provided which includes a handle, a tool member, and a segmented flexible articulating arm which operatively connects the handle and the tool member. Also provided is an instrumentation kit having a surgical instrument which includes an end effector connecting assembly disposed at the distal end portion of an articulating arm to facilitate the removal or attachment of and end effector from the distal end of the articulating arm. The surgical instrumentation kit also includes a number of interchangeable surgical tool end effectors each having a uniform connector portion for interchangeable engagement with the end effector connecting assembly of the surgical instrument.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application claims priority to U.S. Provisional Application Serial No. 60/072,405 filed Jan. 23, 1998 and to U.S. Provisional Application Serial No. 60/105,364 filed Oct. 23, 1998. The contents of each of these applications are hereby incorporated by reference in their entirety. 
     
    
     
       BACKGROUND  
         [0002]    1. Technical Field  
           [0003]    The subject disclosure relates to minimally invasive surgical procedures and apparatus, and more particularly to surgical instrumentation for performing surgery associated with the thoracic cavity.  
           [0004]    2. Background of Related Art  
           [0005]    It is well established that the performance of various types of surgical procedures using less invasive techniques and instrumentation has provided numerous physical benefits to the patient while reducing the overall cost of such procedures. One area, for example, which has experienced a great increase in the performance of less invasive procedures is in the area of heart surgery. In particular, coronary artery bypass graft (CABG) procedures have been performed using less invasive techniques with much success.  
           [0006]    Access to the patient&#39;s thoracic cavity for such procedures in the past was typically achieved by a large longitudinal incision in the chest. This procedure, referred to as a median sternotomy, requires a saw or other cutting instrument to cut the sternum and allow two opposing halves of the rib cages to be spread apart. U.S. Pat. No. 5,025,779 to Bugge discloses a retractor which is designed to grip opposite sternum halves and spread the thoracic cavity apart. The large opening which is created by this technique enables the surgeon to directly visualize the surgical site and perform procedures on the affected organs. However, such procedures that involve large incisions and substantial displacement of the rib cage are often traumatic to the patient with significant attendant risks. The recovery period may be extended and is often painful. Furthermore, patients for whom coronary surgery is indicated may need to forego such surgery due to the risks involved with gaining access to the heart.  
           [0007]    U.S. Pat. No. 5,503,617 to Jako discloses a retractor configured to be held by the surgeon for use in vascular or cardiac surgery to retract and hold ribs apart to allow access to the heart or a lung through an operating window. The retractor includes a rigid frame and a translation frame slidably connected to the rigid frame. Lower and upper blades are rotatably mounted to the rigid frame and the translation frame respectively. Such a “window” approach requires instrumentation that can be inserted into and manipulated within the limited space available in and around the surgical site.  
           [0008]    Therefore, a continuing need exists for more versatile and varied surgical instrumentation which facilitates performing surgical procedures in limited access cavities of a patient during less invasive surgical procedures.  
         SUMMARY  
         [0009]    The present disclosure addresses the above-noted needs while providing surgical instrumentation that has many unique features and advantages over the prior instrumentation. The presently disclosed surgical instrumentation provides greater versatility during surgical procedures which are less invasive than traditional procedures.  
           [0010]    For example, in one embodiment, the present disclosure provides a mounting assembly for mounting a surgical instrument to a base, wherein a clip portion and a cover portion function together to to retain the shaft of a surgical instrument therein and thereby fix the length of the instrument shaft relative to the base and an operative site. This is particularly advantageous in that during surgical procedures where free space in and around the surgical site is at a minimum, the presently disclosed mounting assembly facilitates positioning a surgical instrument relative to the surgical site so that only the minimum portion of the instrument is positioned in the sparse free space.  
           [0011]    In an alternative embodiment, a mounting assembly for mounting a surgical instrument to a base is provided which includes first and second opposed mounting sections. The mounting assembly includes an instrument retaining area configured and dimensioned to removably retain the shaft of a surgical instrument therein.  
           [0012]    In another aspect of the present disclosure, a surgical instrument is provided which includes a handle, a tool member, and an articulating arm which operatively connects the handle and the tool member. The articulating arm includes a number of arm segments and a number of reinforcing segments each of the various segments having a concave surface and a convex surface. The reinforcing segments have a maximum width which is less than a maximum width of the arm segments. In a particularly advantageous feature, the arm segments and reinforcing segments are arranged in a nested series to define a flexible column, wherein a cable extends from the handle through the a passageway in the segments to the distal end of the articulating arm.  
           [0013]    In one aspect of the above embodiment, the reinforcing segments each includes a number of protrusions to facilitate making contact with the inner surface of the adjacent arm segment. In another aspect, each of the protrusions forms a tapered end.  
           [0014]    In another embodiment, the present disclosure provides a surgical instrument including a handle having first and second relatively movable handle portions, a tool member, an articulating arm which operatively connects the handle and the tool member. The articulating arm includes a plurality of arm segments arranged in a series to form a flexible column. A cable is provided which extends from the handle through the passageway to the distal end of the articulating arm such that relative movement of the first and second handle portions to a first predetermined configuration causes the cable to be tensioned a predetermined amount. Finally, a tension adjustment mechanism is provided which includes an actuator and a slide housing operatively associated with the handle, such that upon movement of the actuator within a finite predetermined range of motion, the tension imparted in the cable may be incrementally adjusted and maintained at any magnitude associated with the predetermined range of motion of the actuator.  
           [0015]    In yet another aspect of the present disclosure, a surgical instrument is provided which includes a handle having first and second relatively movable portions, and an articulating arm extending from the handle. The articulating arm includes a number of arm segments arranged in a series to form a flexible column, each of the arm segments defining an aperture therethrough such that a passageway is formed from a proximal end of the articulating arm to a distal end of the articulating arm. A cable is provided which extends from the handle through the passageway to the distal end of the articulating arm such that relative movement of the first and second handle portions to a first predetermined configuration causes the cable to be tensioned a predetermined amount. Finally, the present embodiment includes an end effector connecting assembly disposed at the distal end portion of the articulating arm. The end effector connecting assembly includes a housing, and a coupling member operatively connected to the distal end of the cable and movable relative to the housing from a closed position to an open position. The coupling member is operative to facilitate the removal or attachment of and end effector from the distal end of the articulating arm.  
           [0016]    The present disclosure also provides the user with a uniquely advantageous surgical instrumentation kit including a surgical instrument having a handle, an articulating arm which forms a flexible column, and an end effector connecting assembly disposed at the distal end portion of the articulating arm. The coupling member is capable of retaining a connection portion of an end effector and when disposed in the open position. Preferably, the coupling member facilitates the removal or attachment of and end effector from the distal end of the articulating arm. The surgical instrumentation kit includes a number of interchangeable surgical tool end effectors each having a uniform connector portion for interchangeable engagement with the end effector connecting assembly of the surgical instrument. Finally, the surgical instrumentation kit includes a mounting assembly for mounting the surgical instrument to a base. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    Various preferred embodiments are described herein with reference to the drawings, wherein:  
         [0018]    [0018]FIG. 1 is a perspective view of a first embodiment of a surgical retraction system incorporating a variety of retractors, a heart manipulator and a heart stabilizer, all positioned on a base;  
         [0019]    [0019]FIG. 2 is a perspective view the heart stabilizer of FIG. 1;  
         [0020]    [0020]FIG. 3 is a perspective view showing the instrument mount (holder) of the present disclosure positioned on a base and supporting a heart stabilizer;  
         [0021]    [0021]FIG. 4 is a perspective view showing the instrument holder and the cable locking mechanism, with the integral cable removed for clarity;  
         [0022]    [0022]FIG. 5A is a top perspective view illustrating a first mounting section of the instrument holder;  
         [0023]    [0023]FIGS. 5B and 5C are rear and rear perspective views, respectively, of the first mounting section of FIG. 5A;  
         [0024]    [0024]FIG. 5D is a cross-sectional view of the first mounting section;  
         [0025]    [0025]FIG. 6A is a rear perspective view showing the second mounting section of the instrument holder;  
         [0026]    [0026]FIG. 6B is a perspective view showing the opposite side of the second mounting section of FIG. 6A.  
         [0027]    [0027]FIG. 6C is a cross-sectional view of the second mounting section;  
         [0028]    [0028]FIG. 7 is a cross-sectional view of the screw thread housing of the cable locking mechanism; and  
         [0029]    [0029]FIG. 8 illustrates a side view of the cable of the articulating arm.  
         [0030]    [0030]FIGS. 9 and 10 illustrate perspective and cross-sectional views, respectively, of one of the series of domes mounted on the cable to form an articulating arm;  
         [0031]    [0031]FIG. 11 is a perspective view of an alternative embodiment of a surgical instrument in accordance with the present disclosure;  
         [0032]    [0032]FIG. 12 is a partial perspective view of the underside of a mounting assembly for the embodiment of FIG. 11;  
         [0033]    [0033]FIG. 13 is a partial perspective view illustrating operation of the mounting assembly;  
         [0034]    [0034]FIG. 14 is a partial perspective view illustrating the length adjusting characteristic of the mounting assembly;  
         [0035]    [0035]FIG. 15 is a horizontal cross-sectional view which illustrates a tensioning mechanism which forms a part of the surgical instrument;  
         [0036]    [0036]FIG. 16 is an enlarged view of the indicated area of detail shown in FIG. 15;  
         [0037]    [0037]FIG. 17 is a perspective view with parts separated of one segment of an articulating arm of the present disclosure;  
         [0038]    [0038]FIG. 18 is a perspective view with parts separated showing the relative positioning of two adjacent articulating arm segments;  
         [0039]    [0039]FIG. 19 is a horizontal cross-sectional view similar to FIG. 16, showing operation of the tension adjusting mechanism;  
         [0040]    [0040]FIG. 20 is an enlarged view of the indicated area of detail of FIG. 19;  
         [0041]    [0041]FIG. 21 is a partial perspective view illustrating an end effector mounting structure;  
         [0042]    [0042]FIG. 22 is an enlarged partial perspective view of a connection between an end effector and a distal end portion of the surgical instrument;  
         [0043]    [0043]FIG. 23 is a partial perspective view of a distal end of a heart stabilizer end effector connected to the surgical instrument;  
         [0044]    [0044]FIG. 24 is a view of a bottom surface of the heart stabilizer end effector of FIG. 23;  
         [0045]    [0045]FIG. 25 is a partial perspective view illustrating an alternative embodiment of a heart stabilizing end effector connected to the surgical instrument;  
         [0046]    [0046]FIG. 26 is a partial perspective view illustrating a further alternative heart stabilizing end effector attached to the surgical instrument;  
         [0047]    [0047]FIG. 27 is a partial perspective view illustrating a tissue manipulating end effector connected to the distal end of the surgical instrument;  
         [0048]    [0048]FIG. 28 is a partial perspective view showing an alternative tissue manipulating end effector connected to the distal end of the surgical instrument; and  
         [0049]    [0049]FIG. 29 is a view showing the contents of a kit including a plurality of end effectors and a surgical instrument shown with parts separated. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0050]    The present disclosure is directed to various embodiments of a surgical instrument and assemblies for mounting the surgical instrument to a fixed base such that the length of a shaft of the instrument may be varied relative to the base. Initially, an embodiment of an instrument mounting assembly (holder) will be described with reference to FIGS.  1 - 12 , and will refer to surgical instruments described in a copending application. Thereafter, embodiments of an alternative surgical instrument and mounting assembly will be described with reference to FIGS.  13 - 31 . It is contemplated that the various described mounting assemblies may be used with the various described surgical instruments herein.  
         [0051]    Referring to FIGS.  1 - 12 , the instrument mount (holder) embodiment illustrated therein is designed to enable adjustment of the length of the articulating arm of an instrument such as the heart stabilizer and heart manipulator disclosed in U.S. Pat. application Ser. No. 08/718,283, filed Sept. 20, 1996, the contents of which are incorporated herein by reference in their entirety. FIG. 1 is a drawing from the &#39;283 patent application and shows base  50 , retractors  60 ,  70  and  80 , heart stabilizer  90 , and heart manipulator  100 . A detailed description of these instruments, how they are mounted to the base  50 , and their surgical function is disclosed in the &#39;283 application. FIG. 2 is also a drawing from the &#39;283 application and is included herein for convenience to show a heart stabilizer with an articulating arm  92 .  
         [0052]    Referring to FIGS. 3 and 4, the present disclosure in a first embodiment, includes an instrument holder  10  comprising first and second mounting sections  29  and  30 , respectively which are fitted together by a groove and tongue arrangement. Mounting section  29  includes a lip  12  which is hooked around the front edge  54  of base  50  as shown in FIG. 3. A recess  18 , best shown in FIG. 5, is configured to receive the domes of an articulating arm  62  of heart stabilizer  90 . Referring to FIGS.  5 A- 5 D, articulating arm  62  is positioned in the first mounting section  29  by sliding a cable  47  (FIG. 12) through slot  14  formed in the top of first mounting section  29 . Groove  17  is configured to mount tongue  39  of second mounting section  30  in the manner described below. Bore  19  receives a spring (not shown) which is secured to both mounting sections  29  and  30  to help retain first and second mounting sections  29  and  30  together while allowing them to be pulled slightly away from each other, against the force of the spring, to facilitate mounting to and release from base  50 .  
         [0053]    With reference to FIGS.  6 A- 6 C, second mounting section  30  has a bottom lip  32  with a series of teeth  36  configured to mount to outer edge  56  of base  50  (FIG. 3). A tongue  39  protrudes outwardly from surface  41  to fit within groove  17  of first mounting section  29 . Slot  34 , similar to slot  14  of first mounting section  29 , is configured to receive cable  47  of articulating arm  62  with adjacent domes seated within respective recesses  18  and  38 . Opening  35  is for receiving the biasing spring described above.  
         [0054]    Rotation handle  42  of cable locking mechanism  43  of FIG. 4 is connected to a threaded rod which engages internal threads (not shown) of screw thread housing  44  (FIG. 7). The threaded rod is connected to the proximal end of cable  47  (FIG. 8). Upon rotation of handle  42 , the threaded rod and connected cable  47  are moved out of housing  44  thereby pulling the cable to make articulating arm  62  taut which holds the heart stabilizer in position. For clarity, articulating arm  62  has been omitted from FIG. 4. Articulating arm  62  is formed by a plurality of domes  45 , best shown in FIGS. 9 and 10, mounted on cable  47  (FIG. 8). An opening  46  is formed on each dome  45  to receive the cable therethrough.  
         [0055]    It should be appreciated that while the above structure is described for use with a heart stabilizer it is also contemplated that a heart manipulator or any other instrument which includes the articulating arm  62  can be utilized. Various surgical procedures are also contemplated.  
         [0056]    The use of the instrument holder will now be described in conjunction with a heart stabilizer for convenience. After the user decides where the stabilizer should be positioned, first and second mounting sections  29 ,  30  are pulled slightly apart to allow the lips  12  and  32  to engage the edges of the base  50 . When released, the spring pulls first and second mounting sections  29  and  30  into abutment as shown in FIG. 3. The desired length of the stabilizer is identified and the appropriate portion of the cable  47  is placed through the slots  14  and  34  of first and second mounting sections  29  and  30 . That is, if a shorter length stabilizer is desired, a more distal portion of articulating arm will be inserted through slots  14  and  13 ; if a larger length is desired, a more proximal portion will be inserted. Reference letter “L” and “S” in FIG. 3 provide by way of example, a sample location for a longer or shorter stabilizer, respectively, with respect to the position of FIG. 3. After articulating arm  62  is positioned in first and second mounting sections  29 ,  30 , articulating arm  62  is maneuvered so the heart stabilizer is in the appropriate position. Rotation knob  42  is then rotated to retract the cable  47  to make articulating arm  62  rigid so as to maintain the stabilizer in the desired orientation relative to the heart tissue.  
         [0057]    Referring now to FIGS.  11 - 29 , an alternative embodiment of a surgical instrument generally designated as surgical instrument  200  will now be described in detail. Briefly, similar to the instrument embodiment described above, surgical instrument  200  includes a multi-configurable articulating arm  210  which is operable from a freely flexible condition to a rigid, locked configuration by way of a handle assembly  212 . Surgical instrument  200  further includes a tension adjusting mechanism  214  to vary the degree of tension imparted in a cable of articulating arm  210 . This enables the flexibility of the arm to be selectively adjusted. Surgical instrument  200  is further provided with one or more interchangeable end effectors or tools such as a heart stabilizer end effector  216  as shown in FIG. 11. The present disclosure also provides a mounting member, for example clamp  218 , which provides for the secure and fixed attachment of surgical instrument  200  to a base  220 .  
         [0058]    Referring to FIGS.  11 - 15 , clamp  218  as noted above, serves to removably attach surgical instrument  200  to base  220 . Clamp  218  is secured to a base  220  by snapping lip portions  218   a  and  218   b  of a clip poriton  218   e  over inner and outer rim portions  220   a  and  220   b  of base member  220 , respectively. A key portion  218   c  is formed on the underside of clamp  218  as shown in FIG. 12, and is configured and dimensioned to fit within keyways  220   c  formed around the periphery of base  220 . In this manner, clamp  218  is prevented from sliding along base  220  thereby providing a secure rigid attachment of instrument  210  to base  220 .  
         [0059]    Another particularly advantageous feature is illustrated in FIGS. 13 and 14 wherein the relative length of articulating arm  210  of instrument  200  may be lengthened or shortened with respect to base  220  by way of clamp  218 . In particular, clamp  218  is provided with a pivotally mounted locking cover  218   d . Clamp  218  is preferably molded to form an inner channel when closed to conform to the shape of articulating arm  210 . To adjust the length of articulating arm  210  relative to base  220 , locking cover  218   d  is pivoted open as indicated by arrow “A” in FIG. 13. Articulating arm  210  is moved to the desired length adjusted position, for example, proximally as indicated by arrow “B” in FIG. 14. “Length adjusted position” in this context refers to the length or amount of articulating arm  210  that is distal of the clamp and which extends through the opening of base  220  to the tissue site. Locking cover  218   d  is pivoted closed over the top of clip portion  218   e  so that knurled portions, such as teeth  218   f  formed on the inner surface of locking cover  218   d , mesh with correspondingly shaped knurled portions or teeth  222  formed along periphery of the articulating arm segments. Locking cover  218   d  is secured in the locked position by the engagement of latch  218   g  with lock plate  218   h .  
         [0060]    Alternatively, articulating arm  210  may also be positioned in clamp  218  at any position along the length of articulating arm  210  and then mounting the assembled clamp and instrument to the base without having to subsequently reposition the instrument.  
         [0061]    The structure and operation of the multi-configurable articulating arm  210  will now be described in detail with reference to FIGS.  15 - 20 . Articulating arm  210  includes a series of elements  224  axially disposed about a flexible tensioning member such as cable  226  which is secured at a proximal end in movable tension control member  212   b  and at a distal end to end effector coupling  228 . A coil spring  230  is also disposed on or around cable  226  between coupling  228  and a stepped through-bore  232  formed through coupling housing member  234  which is disposed about a bulbous distal end  236  of cable  226 .  
         [0062]    Tension adjusting mechanism  214  includes housing portion  238  which includes a lateral slot formed therethrough to longitudinally retain a tension adjusting actuator member such as threaded dial  240 , while permitting rotation thereof. Handle assembly  212  includes a distally extending threaded shaft portion  242  which is threadably received within dial  240  to facilitate selective proximal or distal selective movement of handle assembly  212  with respect to housing portion  238 . Referring to FIGS.  16 - 18 , each of articulating arm elements  224  include a dome shaped segment such as arm segment  224   a  and a reinforcing segment such as insert segment  224   b  snap fitted to the outer distal surface of arm segment  224   a . Arm segments  224   a  are preferably formed of a polycarbonate material or the like while insert segments  224   b  are preferably formed of a metal material to provide reinforcing strength to enhance the rigidity of articulating arm  210  when in a tensioned condition. Arm segments  224   a  are preferably provided with molded recessed surfaces on a distal end thereof which correspond to and receive a proximal flange  224   c  of insert segments  224   b . As best shown in FIG. 16, the internal diameter of inserts  224   b  as defined by inner surface  224   d  is much greater than the internal diameter defined by inner surface  224   e  of arm segments  224   a . This construction facilitates flexion of articulating arm  210  so that cable  226  is guided in the general configuration of articulating arm  210  by arm segments  224   a  but permitted to swing through a greater arc prior to contacting inner surfaces  224   d  of inserts  224   b . Furthermore, arm segments  224   a  are provided with shoulder portions  224   f  which serve to prevent significant gaps or pinch points from forming between adjacent articulating arm segments upon flexion thereof. Insert segments  224   b  are further provided with a series of conically shaped protrusions  224   g  which come to a point and serve as sharpened contact engagement points with the proximal surfaces of arm segments  224   a  upon tensioning of articulating arm  210 .  
         [0063]    In operation, as shown in FIGS. 19 and 20, the tension adjusting mechanism may be adjusted to increase or decrease the amount of tension imparted to the cable  226  thereby adjusting the compression in the arm segments  224   a  and insert segments  224   b  and thus the rigidity of articulating arm  210  by way of adjusting dial  240 . For example, dial  240  may be rotated in a clockwise fashion, as viewed from a proximal perspective indicated by arrow “D” in FIG. 19, to increase the amount of tension in cable  226  by moving handle assembly  212  proximally in the direction of arrows “E” with respect to housing section  238 , thus providing a less flexible articulating arm  210 . Conversely, dial  240  may be rotated in the opposite direction to decrease the amount of tension in cable  226 , thus providing a more flexible articulating arm  210 . Therefore, the flexibility of articulating arm  210  may be adjusted to suit the individual user&#39;s preference.  
         [0064]    During a given surgical procedure, articulating arm  210  (which is either initially in a non-locked configuration or is placed in such configuration) is manipulated by the user to the desired configuration and/or position at the surgical site. To lock articulating arm  210  in the desired configuration, tension control lever  212   b  is squeezed toward stationary housing portion  212   a . Cable  226  which is anchored in tension control lever  212   b  is thereby pulled proximally in the direction of arrows “E” of FIG. 19 such that insert segments  224   b , which are axially aligned relative to each other, impinge into the inner surfaces of arm segments  224   a  to enhance the rigidity of articulating arm  210  and reduce the stresses created on arm segments  224   a  by reducing the moment arm length with respect to cable  226 .  
         [0065]    As illustrated in FIGS.  21 - 28 , surgical instrument  200  includes an end effector connecting assembly formed at the distal end of articulating arm  210 . An end effector, such as tissue manipulating attachment  244 , is provided with a connector hub  246  disposed at a proximal end of a shaft portion  248  which is secured to the operative portion of the end effector such as stabilizer contact frame member  250 . Hub portion  246  is received within a laterally directed opening  252  formed through distal end housing segment  234  and coupling member  228  as well as yoke  254  which is retained by coupling member  228  at the open distal end of housing section  234 .  
         [0066]    To attach a particular end effector to the distal end of articulating arm  210 , tension control lever  212   b  is opened to its fully spaced-apart position away from stationary handle section  212   a . Tension adjusting dial  240  is rotated to advance handle assembly  212  to its most closely approximated orientation with respect to slide housing  238  in order to enable spring  230  to bias coupling member  228  distally away from the open end of distal housing section  234 . In this manner, a sufficient gap is formed between coupling  228  and the distal surface of housing  234  to permit the entry of hub  246  in lateral opening  252 . Once the desired end effector is inserted in lateral opening  252 , tension adjusting dial  240  is rotated to effect proximal movement of handle assembly  212  with respect to slide housing  238  in order to move coupling  228  proximally to secure the end effector within the distal end portion of articulating arm  210 .  
         [0067]    Various types of end effectors are contemplated for usage in connection with surgical instrument  200 . Some examples of such end effectors are illustrated throughout FIGS.  23 - 28 . For example, in the case of a procedure performed on the heart, heart stabilizing end effectors such as those shown in FIGS.  23 - 26  may be utilized in conjunction with instrument  200 . In FIG. 23, heart stabilizer  256  is similar to heart stabilizer  216  (FIG. 15) except that mounting hub  246  is disposed away from end effector  256  at an angle significantly different from that of mounting hub  246  of end effector  216 . Thus, when mounted upon instrument  200 , heart stabilizer end effector  256  is oriented relative to the distal end of flexible arm  210  such that leg portions  256   a  and  256   b  extend at a much greater angle relative to a longitudinal axis of distal housing  234  than that of end effector  216 . Although only two different angle settings are illustrated for the mounting of the working portions of the end effectors with respect to articulating arm  210 , many different mounting angle may also be utilized, and are also contemplated by the present disclosure.  
         [0068]    As shown in FIG. 24, it is contemplated that the various heart stabilizer end effectors may have protrusions extending from bottom surfaces of leg portions of the end effectors such as leg portions  216   a  and  216   b  so as to provide a gripping surface to better grip tissue contacted by the leg portions. Protruding portions  258  may be provided as circular flat extended protrusions as shown in FIGS. 15 and 24 or may have other suitable geometrical configurations to enhance gripping with the tissue surface.  
         [0069]    [0069]FIG. 25 illustrates a further alternative heart stabilizer end effector  260  which is similar to heart stabilizer end effector  256  except that leg portions  260   a  and  260   b  are substantially planar in comparison with the arcuately flared leg portions  256   a  and  256   b  of heart stabilizer end effector  256 . Similarly, FIG. 26 features heart stabilizer end effector  262  having substantially planar leg portions  262   a  and  262   b  in contrast to the arcuately flared leg portions  216   a  and  216   b  of heart stabilizer end effector  216  (FIG. 15).  
         [0070]    Referring to FIG. 27, a tissue manipulating end effector  244  is shown attached to the distal end of articulating arm  210 . Tissue manipulating end effector  244  includes a rigid peripheral frame member  264  and a flexible tissue contacting material such as mesh  266 . Other surfaces or materials are contemplated for tissue manipulating end effector  244  such as solid materials of plastic, metal or the like. Referring to FIG. 28, an alternative embodiment of a tissue manipulating member is shown as tissue manipulating end effector  268  which includes a greater surface area over which to contact and manipulate tissue therewith.  
         [0071]    Referring to FIG. 29, one exemplary embodiment of an instrument kit is shown wherein the kit includes a surgical instrument  200  (shown with parts separated for illustrative components of the various structural members) and a number of different end effectors which will provide the surgeon with a greater selection and versatility throughout the surgical procedure. For example, a full range of heart stabilizing end effectors  216 ,  256 ,  262  and  260  having varying mounting orientations and leg configurations may be included. Additionally, differing tissue manipulating end effectors such as end effectors  244  and  268  may be included to also provide the user with a greater range of selection for a particular procedure.  
         [0072]    It will be understood that various modifications may be made to the embodiments shown herein. Therefore, the above description should not be construed as limiting, but merely as exemplications of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the present disclosure.