Abstract:
The present invention relates to a minimally invasive surgical instrument having a shaft including an internal torque transmission member. According to one aspect of the present invention, the minimally invasive surgical instrument comprises a shaft, and an end effector connected to one end of the shaft. The shaft has at least one curved portion, and the at least one curved portion can transmit torque for operating the end effector in a rolling direction by means of a torque-transmission member therein.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a minimally invasive surgical instrument having a shaft including an internal torque transmission member. 
       BACKGROUND 
       [0002]    Minimally invasive surgery is a surgical approach that involves the use of instruments inserted through several tiny incision openings to perform a surgery causing minimal tissue trauma in human or animal bodies. 
         [0003]    The minimally invasive surgery relatively reduces changes in metabolism of a patient in the period of post-surgical care, so it facilitates rapid recovery of the patient. Therefore, the minimally invasive surgery shortens the length of hospitalization of the patient after the surgery and allows the patient to return to normal physical activities in a short period of time. In addition, the minimally invasive surgery causes less pain and leaves fewer scars on the patient&#39;s body after the surgery. 
         [0004]    One of the general forms of the minimally invasive surgery is endoscopy. Among the others, a laparoscopy that involves minimally invasive inspection and operation inside abdominal cavity is known as the most general form of endoscopy. To operate a standard laparoscopic surgery, the abdomen of the patient is insufflated with gas and at least one small incision is formed to provide an entrance for laparoscopic surgical instruments, through which a trocar is inserted. When performing the surgery, it is general that a user puts the laparoscopic surgical instruments into a surgical site or the like through the trocar, and manipulates (or controls) the instruments from the outside of abdominal cavity. In general, the laparoscopic surgical instruments include a laparoscope (for observation of a surgical site) and other working tools. Herein, the working tools are similar to the conventional tools used for small incision surgery, except that the end effector or working end of each tool is separated from its handle or the like by a shaft. For instance, the working tools may include a clamp, a grasper, scissors, a stapler, a needle holder, and so forth. Meanwhile, the user monitors the procedure of the surgery through a monitor that displays the images of the surgical site which are taken by the laparoscope. The endoscopic approaches similar to the above are broadly used in retroperitoneoscopy, pelviscopy, arthroscopy, cisternoscopy, sinuscopy, hysteroscopy, nephroscopy, cystoscopy, urethroscopy, pyeloscopy, and so on. 
         [0005]    The inventor(s) has developed various minimally invasive surgical instruments useful for the above-mentioned minimally invasive surgeries and has already disclosed the features of the structures and effects of the same in Korean Patent Application Nos. 2008-51248, 2008-61894, 2008-79126 and 2008-90560, the contents of which are incorporated herein by reference in its entirety. Additionally, the inventor(s) have also introduced a minimally invasive surgical instrument with improved functionality, which is more advantageous for users and patients, in Korean Patent Application Nos. 2010-115152 and 2011-3192, the contents of which are incorporated herein by reference in its entirety. 
         [0006]    Herein, the inventor(s) now present a minimally invasive surgical instrument that may be more conveniently manipulated by a user while retaining the functional advantages of the minimally invasive surgical instruments disclosed in the above Korean applications. 
       SUMMARY OF THE INVENTION 
       [0007]    One object of the present invention is to solve all the above problems in prior art. 
         [0008]    Another object of this invention is to provide a minimally invasive surgical instrument having a bent shaft wherein an end effector has good characteristics in terms of its roll direction operation. 
         [0009]    Yet another object of this invention is to provide a minimally invasive surgical instrument wherein the collision of end effectors may be avoided when two or more minimally invasive surgical instruments are used together. 
         [0010]    Still another object of this invention is to provide a minimally invasive surgical instrument wherein the interference of handling units may be avoided when two or more minimally invasive surgical instruments are used together. 
         [0011]    According to one aspect of the invention to achieve the objects as described above, there is provided a minimally invasive surgical instrument comprising a shaft and an end effector being connected to one end of the shaft, wherein the shaft comprises at least one bend and the at least one bend is capable of transmitting torque to operate the end effector in a roll direction by means of a torque transmission member therein. 
         [0012]    In addition, there may be provided other ways to implement this invention. 
         [0013]    According to the invention, there is provided a minimally invasive surgical instrument having a bent shaft wherein an end effector has good characteristics in terms of its roll direction operation. 
         [0014]    According to the invention, there is provided a minimally invasive surgical instrument wherein the collision of end effectors may be avoided when two or more minimally invasive surgical instruments are used together. 
         [0015]    According to the invention, there is provided a minimally invasive surgical instrument wherein the interference of handling units may be avoided when two or more minimally invasive surgical instruments are used together. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  shows the overall appearance of a minimally invasive surgical instrument according to one embodiment of the invention. 
           [0017]      FIG. 2  shows the interior of a first bend  131  and a second bend  132  of  FIG. 1 . 
           [0018]      FIG. 3  is a cross-sectional view of a first flexible resin  133  of  FIG. 2 . 
           [0019]      FIG. 4  shows the configuration of the first flexible resin  133  of  FIG. 2  in detail. 
           [0020]      FIG. 5  is an exploded view of a part of a handling unit  110  of  FIG. 1 . 
           [0021]      FIG. 6  shows the interior of a part of a minimally invasive surgical instrument according to another embodiment of the invention. 
           [0022]      FIG. 7  is a cross-sectional view of a part of a first bend  131  of  FIG. 6 . 
           [0023]      FIG. 8  shows how an end effector  100  and a first rotating member  133 ′ of  FIG. 6  are connected. 
           [0024]      FIG. 9  is an exploded view of a part of a handling unit  110  of  FIG. 6 . 
           [0025]      FIG. 10  shows the interior of a part of a minimally invasive surgical instrument according to yet another embodiment of the invention. 
           [0026]      FIG. 11  shows how an end effector  100  and an adjacent rotating member  136 ″ of  FIG. 10  are connected. 
           [0027]      FIG. 12  is an exploded view of some components shown in  FIG. 11 . 
           [0028]      FIG. 13  shows how opening/closing wires (OW) are connected in a minimally invasive surgical instrument according to an embodiment of the invention. 
           [0029]      FIG. 14  shows the interior of a part of a minimally invasive surgical instrument according to still another embodiment of the invention. 
           [0030]      FIGS. 15 and 16  are exploded views showing how a tube unit  136 ′″ of  FIG. 14  is connected to an end effector  100  and a handling unit  110 , respectively. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0031]    In the following detailed description of the invention, references are made to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that the various embodiments of the invention, although different from each other, are not necessarily mutually exclusive. For example, specific shapes, structures, or characteristics described herein may be implemented as modified from one embodiment to another embodiment without departing from the spirit and the scope of the invention. Furthermore, it shall be understood that the locations or arrangements of individual elements within each embodiment may be also modified without departing from the spirit and the scope of the invention. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of the invention is to be taken as encompassing the scope of the appended claims and all equivalents thereof. In the drawings, like reference numerals refer to the same or similar elements throughout the several views. 
         [0032]    Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings to enable those skilled in the art to easily implement the invention. 
       First Embodiment 
       [0033]      FIG. 1  shows the overall appearance of a minimally invasive surgical instrument according to one embodiment of the invention. Further,  FIG. 2  shows the interior of a first bend  131  and a second bend  132  of  FIG. 1   
         [0034]    Reference will be made to  FIG. 1 . The minimally invasive surgical instrument according to the present embodiment may comprise an end effector  100  to perform surgery by using surgical tools (not shown) or functioning itself as a surgical tool; a handling unit  110  to control the operation of the end effector  110  according to a user&#39;s manipulation; a shaft  130  to connect the end effector  100  and the handling unit  110 , wherein the end effector  100  is disposed at one end of the shaft  130  such that it may operate in a roll direction and the handling unit  110  is disposed at the other end; and a first bend  131  and a second bend  132  in the shaft  130 . As shown, the first bend  131  may be disposed close to the end effector  100 , and the second bend  132  may be disposed close to the handling unit  110 . The first bend  131  may be formed in a curved shape as shown so that the collision or the like of the end effectors  100  may be avoided when two or more minimally invasive surgical instruments are used together. The second bend  232  may be formed in a shape spreading outwardly from the longitudinal central axis of the shaft  130  as shown, so that the interference or the like of the handling units  110  may be avoided when two or more minimally invasive surgical instruments are used together. 
         [0035]    Reference will be made to  FIG. 2 . The shaft  130  may include therein a first flexible resin  133 , a second flexible resin  134  and a plurality of linear members  136 . (The flexible resins may be formed from Teflon or the like, and the preferably cylindrical linear members  136  may be formed from a rigid material.) The first flexible resin  133  and the second flexible resin  134  may substantially correspond to the first bend  131  and the second bend  132  of the shaft  130  located outside the flexible resins, respectively, so that they are connected between the end effector  100  and the handling unit  110  by means of the linear members  136 . When the user rotates a roll sprocket  155  included in the handling unit  110  (i.e., applies torque to the roll sprocket  155 ), the flexible resins  133  and  134  may operate the end effector  100  in the roll direction even though the shaft  130  does not operate in the roll direction. (In this case, the flexible resins  133  and  134  and the linear members  136  may also operate in the roll direction together with the end effector  100 .) 
         [0036]      FIG. 3  is a cross-sectional view of the first flexible resin  133  of  FIG. 2 . Further,  FIG. 4  shows the configuration of the first flexible resin  133  of  FIG. 2  in detail. 
         [0037]    Reference will be made to  FIGS. 3 and 4 . As shown in  FIG. 4 , the first flexible resin  133  may have a configuration in which a bending member A bendable in a pitch direction and a bending member B bendable in a yaw direction are alternately arranged. The bending member A may be comprised of two annular members (a1 and a3) and one connecting member (a2) to connect the annular members therebetween. (The connecting member a2 may preferably be disposed on a central axis of the annular members a1 and a3.) The connecting member a2 may allow the bending member A to bend only in the pitch direction. In the same way, the bending member B may be configured to bend only in the yaw direction. 
         [0038]      FIG. 5  is an exploded view of a part of the handling unit  110  of  FIG. 1 . 
         [0039]    Reference will be made to  FIG. 5 . The linear members  136  are connected with the roll sprocket  155  so that when the user rotates the roll sprocket  155 , the rotation may be transmitted to the second flexible resin  134 , the first flexible resin  133  and the end effector  100  connected thereto. In this case, the shaft  130  does not operate in the roll direction while only the flexible resins  133  and  134  and the linear members  136  operate in the roll direction. Eventually, the end effector  100  may operate in the roll direction almost without any other operations. Meanwhile, when the user manipulates a rotatable handle  113  of the handling unit  110 , the opening/closing wires  179  connected thereto are pushed or pulled to open or close the end effector  100 , as disclosed in the above-mentioned Korean applications. 
         [0040]    With regard to the various following embodiments, the configurations which are different or modified from that of the first embodiment will be mainly described below. 
       Second Embodiment 
       [0041]      FIG. 6  shows the interior of a part of a minimally invasive surgical instrument according to another embodiment of the invention. 
         [0042]    Reference will be made to  FIG. 6 . 
         [0043]    The minimally invasive surgical instrument according to the present embodiment may comprise an end effector  100 , a handling unit  110 , a shaft  130 , a first bend  131  and a second bend  132 , in the same manner as the first embodiment. According to the present embodiment, the end effector  100  may also carry out the roll direction and/or opening/closing operations. 
         [0044]    The shaft  130  may include first to fourth rotating members  133 ′- 136 ′ therein. As shown, the first to fourth rotating members  133 ′- 136 ′ may be surrounded by the shaft  130  as they are sequentially connected from the end effector  100  to the handling unit  110 . In order to achieve the unique effects of the present invention, each of the first to fourth rotating members  133 ′- 136 ′ may be connected to an adjacent rotating member as being tilted at an angle relative to the adjacent rotating member. The first bend  131  and the second bend  132  may be the bends in the shaft  130  resulting from such tilt. 
         [0045]    The first to fourth rotating members  133 ′- 136 ′ may act together to transmit the rotation from the handling unit  110  to the end effector  100 , thereby operating the end effector  100  in the roll direction. (In this case, the shaft  130  may not operate in the roll direction.) In order to act together in the above manner, the first to fourth rotating members  133 ′- 136 ′ may have a crown or bevel gear element at at least one of both ends thereof. At least some of the first to fourth is rotating members  133 ′- 136 ′ may be formed from a rigid material having small torsion so as to facilitate the transmission of the rotation. 
         [0046]      FIG. 7  is a cross-sectional view of a part of the first bend  131  of  FIG. 6 . 
         [0047]    Reference will be made to  FIG. 7 . As shown, each of the second and third rotating members  134 ′ and  135 ′ may include a crown gear element at one end which obliquely engages with each other. Typically, since the crown gear elements of the second and third rotating members  134 ′ and  135 ′ do not engage with each other entirely but obliquely, only some cogs thereof may engage with each other. When such mechanical structure is exposed in the body of a patient, it may cause harm to the patient and also get easily damaged. Thus, each of the rotating members  133 ′- 136 ′ and the connecting parts thereof need to be water-tightly surrounded by the shaft  130 . 
         [0048]      FIG. 8  shows how the end effector  100  and the first rotating member  133 ′ of  FIG. 6  are connected. 
         [0049]    Reference will be made to  FIG. 8 . As shown, pin holes (PH) may be formed at one end of the end effector  100  on the opposite side of pincers for holding surgical instruments and at the opposing end of the first rotating member  133 ′. Therefore, the end effector  100  may be attached to or detached from the first rotating member  133 ′ included in the shaft  130  as necessary (by means of a pin (not shown)). 
         [0050]      FIG. 9  is an exploded view of a part of the handling unit  110  of  FIG. 6 . 
         [0051]    Reference will be made to  FIG. 9 . As shown, the fourth rotating member  136 ′ may be connected with the roll sprocket  155  by means of a rotator member  140 . Accordingly, when the user rotates the roll sprocket  155 , the rotation may be transmitted via the rotator member  140  connected thereto and further via the fourth to first rotating members  136 ′- 133 ′ to the end effector  100 . In this case, the shaft  130  does not operate in the roll direction while only the rotating members  133 ′- 136 ′ and the rotator member  140  operate in the roll direction. Eventually, the end effector  100  may operate in the roll direction almost without any other operations. 
         [0052]    Meanwhile, when the user manipulates a rotatable handle (not shown) of the handling unit  110 , the opening/closing wires (not shown) connected thereto are pushed or pulled to open or close the end effector  100 , in the same manner as the first embodiment. To implement such configuration, cavities may be formed within the above-mentioned rotating members  133 ′- 136 ′ and rotator member  140 . 
       Third Embodiment 
       [0053]      FIG. 10  shows the interior of a part of a minimally invasive surgical instrument according to yet another embodiment of the invention. 
         [0054]    Reference will be made to  FIG. 10 . 
         [0055]    The minimally invasive surgical instrument according to the present embodiment may comprise an end effector  100 , a handling unit  110 , a shaft  130 , a first bend  131  and a second bend  132 , in the same manner as the first embodiment. According to the present embodiment, the end effector  100  may also carry out the roll direction and/or opening/closing operations. 
         [0056]    The shaft  130 , particularly the first and second bends  131  and  132  may include therein a plurality of universal joints  139  and a plurality of rotating members  136 ″ being connected to the universal joints  139  at at least one of both ends thereof. In order to achieve the unique effects of the present invention, each of the plurality of rotating members  136 ″ may be connected to each other with a corresponding one of the universal joints  139  being interposed therebetween as illustrated, so that they have tilt angles and lengths suitable to form the first and second bends  131  and  132 . 
         [0057]      FIG. 11  shows how the end effector  100  and the adjacent rotating member  136 ″ of  FIG. 10  are connected. 
         [0058]    Reference will be made to  FIG. 11 . As shown, the end effector  100  and the adjacent rotating member  136 ″ may be connected via the universal joint  139  and the connecting member  138  fixed to the end effector  100 . (In this case, there may be formed in the universal joint  139  a plurality of joint holes (JH) to be described below.) The rotating member  136 ″ may transmit the received rotation to the end effector  100  via the universal joint  139  and the connecting member  138 , almost without causing the end effector  100  to operate in the other directions. In this case, the rotation received by the rotating member  136 ″ may be transmitted from the handling unit  110  via several other rotating members  136 ″ in the same manner. 
         [0059]      FIG. 12  is an exploded view of some components shown in  FIG. 11 . 
         [0060]    Reference will be made to  FIG. 12 . As shown, the universal joint  139  for connecting the connecting member  138  and the rotating member  136 ″ may comprise one cube gimbal  171  and two U-shaped members  172 . The two U-shaped members  172  may be respectively disposed at the ends of the connecting member  138  and the rotating member  136 ″ so that they are connected to each other with the one cube gimbal  171  being interposed therebetween by means of pins (not shown) being inserted into the joint holes (JH) of the cube gimbal  171  and the U-shaped members  172 . 
         [0061]      FIG. 13  shows how opening/closing wires (OW) are connected in a minimally invasive surgical instrument according to an embodiment of the invention. 
         [0062]    Reference will be made to  FIGS. 12 and 13 . As shown, the opening/closing wires (OW) which may perform the same function as discussed with the first embodiment may be connected from the end effector  100  to the handling unit  110  via the connecting member  138 , the universal joint  139 , the rotating member  136 ″ and the like. To implement such configuration, cavities for passing the opening/closing wires (OW) may be formed within the connecting member  138  and the rotating member  136 ″. The opening/closing wires (OW) may traverse the universal joint  139  through the joint holes (JH) thereof. 
       Fourth Embodiment 
       [0063]      FIG. 14  shows the interior of a part of a minimally invasive surgical instrument according to still another embodiment of the invention. 
         [0064]    Reference will be made to  FIG. 14 . 
         [0065]    The minimally invasive surgical instrument according to the present embodiment may comprise an end effector  100 , a handling unit  110 , a shaft  130 , a first bend  131  and a second bend  132 , in the same manner as the first embodiment. According to the present embodiment, the end effector  100  may also carry out the roll direction and/or opening/closing operations. 
         [0066]    The shaft may include therein a long tube unit  136 ′″ to connect the end effector  100  and the handling unit  110 . The tube unit  136 ′″ may be formed from a long strip of metallic or nonmetallic material being wound in a coil shape. In order to achieve the unique effects of the present invention, the tube unit  136 ′″ may have a shape suitable to form the first and second bends  131  and  132 . 
         [0067]    The tube unit  136 ′″ may transmit the rotation received from the handling unit  110  to the end effector  100  almost without causing the end effector  100  to operate in the other directions. 
         [0068]      FIGS. 15 and 16  are exploded views showing how the tube unit  136 ′″ of  FIG. 14  is connected to the end effector  100  and the handling unit  110 , respectively. 
         [0069]    First, as shown in  FIG. 15 , pin holes (PH) are formed at the end of the tube unit  136 ′″ facing the end effector  100  so that the tube unit  136 ′″ may be fixed to the end effector  100  by means of a pin (not shown). 
         [0070]    Further, as shown in  FIG. 16 , the end of the tube unit  136 ′″ facing the handling unit  110  may be formed so that it may be connected to a rotator member  140  included in and connected to the handling unit  110  to receive the rotation thereof. More specifically, a cavity (not shown) may be formed at the central part of the end of the tube unit  136 ′″ facing the handling unit  110 , wherein the cavity has a shape suitable to allow the tube unit  136 ′″ to receive the above rotation from the rotator member  140 . Due to the above configuration, when a rotation of the rotator member  140  is caused in the handling unit  110 , the resulting torque may be transmitted to the end effector  100  via the end of the tube unit  136 ′″ facing the handling unit  110 , a coil-shaped tube of the tube unit  136 ′″ and the end of the tube unit  136 ′″ facing the end effector  100  to allow the end effector  100  to operate in the roll direction. 
         [0071]    Meanwhile, it will be apparent to those skilled in the art that a cavity may also be formed in the tube unit  136 ′″ in the present embodiment so that the opening/closing wires (not shown) may pass through the interior thereof. 
         [0072]    Further, the present embodiment may be considered to encompass the configuration in which the above-described coil-shaped tube of the tube unit  136 ′″ is replaced by a non-coil-shaped tube such as a known torsion tube (not shown). 
         [0073]    Applications 
         [0074]    According to an application of the present invention, at least some of the components such as the handling unit  110  and the like of the minimally invasive surgical instrument may be changed or modified to those suitable to be driven by a motor-based system (not shown) such as a surgical robot, so that the minimally invasive surgical instrument may be configured to be controlled by an automatic (or semi-automatic) manipulation system rather than the user&#39;s manual manipulation. 
         [0075]    For example, an electric motor included in a surgical robot (not shown) may operate the end effector  100  in the roll direction by directly rotating at least one of the linear members  136 , rotating members  136 ′, rotating members  136 ″, tube unit  136 ″, rotator member  140  and roll sprocket  155 . 
         [0076]    For another example, the electric motor may control the opening or closing of the end effector  100  by directly pulling the opening/closing wires (OW). 
         [0077]    For yet another example, a system may fix the rolling state or opening/closing state of the end effector  100  by controlling the drive of the electric motor. 
         [0078]    Although the present invention has been described in terms of specific items such as detailed elements as well as the limited embodiments and the drawings, they are only provided to help general understanding of the invention, and the present invention is not limited to the above embodiments. It will be appreciated by a person of ordinary skill in the art that various modifications and changes may be made from the above description. 
         [0079]    Therefore, the spirit of the present invention shall not be limited to the above-described embodiments, and the entire scope of the appended claims and their equivalents will fall within the scope and spirit of the invention.