Abstract:
The present invention relates to a minimally invasive surgical instrument having an articulation immobilising structure. The present invention is a s minimally invasive surgical instrument and includes a shaft, an end effector connected towards one end of the shaft, a wire for controlling the articulated movement of the end effector, and an immobilising structure adapted to immobilise the state of articulated movement of the end effector. The immobilising structure includes a resilient member covering the wire, and the resilient member holds the wire when an internal space therein contracts.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a minimally invasive surgical instrument having a joint fixing structure. 
       BACKGROUND 
       [0002]    Minimally invasive surgery is a surgical approach that involves the use of instruments inserted through at least one tiny incision opening 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 to be regarded as being 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, 2011-3192, 2011-26243, 2011-29771, 2011-86738, 2011-89854 and the like, the contents of which are to be regarded as being incorporated herein by reference in its entirety. 
         [0006]    Herein, the inventor(s) now present a joint fixing structure having excellent capabilities, which may be widely employed in the minimally invasive surgical instruments disclosed in the aforementioned Korean patent applications or other minimally invasive surgical instruments. 
       SUMMARY OF THE INVENTION 
       [0007]    One object of the present invention is to provide a minimally invasive surgical instrument having a joint fixing structure to hold a wire for controlling joint motion of an end effector so that the state of the joint motion thereof may be firmly fixed. 
         [0008]    According to one aspect of the invention to achieve the object as described above, there is provided a minimally invasive surgical instrument comprising a shaft; an end effector being connected to one end of the shaft; a wire to control joint motion of the end effector; and a fixing structure to fix the state of the joint motion of the end effector, wherein the fixing structure comprises an elastic member surrounding the wire, and the elastic member holds the wire as an internal space thereof is reduced. 
         [0009]    According to the invention, there is provided a minimally invasive surgical instrument having a joint fixing structure to hold a wire for controlling joint motion of an end effector so that the state of the joint motion thereof may be firmly fixed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  shows the overall appearance of a minimally invasive surgical instrument according to one embodiment of the invention. 
           [0011]      FIG. 2  is a partial cross-sectional view of the minimally invasive surgical instrument shown in  FIG. 1 . 
           [0012]      FIG. 3  is a partial cross-sectional view of a fixing structure  100  shown in  FIG. 2 . 
           [0013]      FIG. 4  is a perspective view of a fixing structure  100  according to another embodiment of the invention. to  FIG. 5  shows a C-shaped ring  120  among the components of the fixing structure  100  shown in  FIG. 4 . 
           [0014]      FIG. 6  is a perspective view of a fixing structure  100  according to yet another embodiment of the invention. 
           [0015]      FIG. 7  is a perspective view of a fixing structure  100  according to still another embodiment of the invention. 
           [0016]      FIG. 8  is a perspective view of a wire fixing assistance member  141  among the components of the fixing structure  100  shown in  FIG. 7 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]    In the following detailed description of the present 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 and characteristics described herein may be implemented as modified from one embodiment to another without departing from the spirit and scope of the invention. Furthermore, it shall be understood that the locations or arrangements of individual components within each embodiment may also be modified without departing from the spirit and 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. 
         [0018]    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. 
         [0019]    Meanwhile, it should be understood that the term “connection” herein encompasses a direct connection or an indirect connection (i.e., via separate components) between mechanical or other types of components. For example, a connection between two rotating components may be a direct connection formed by the engagement of corresponding gear elements or the like, but may also be an indirect connection via a separate component such as a cable or a groove. 
         [0020]      FIG. 1  shows the overall appearance of a minimally invasive surgical instrument according to one embodiment of the invention. 
         [0021]    Reference will be made to  FIG. 1 . The minimally invasive surgical instrument may comprise a fixing structure (i.e. joint fixing structure)  100 ; a shaft  200  being connected to the fixing structure  100 ; a handling unit  300  that may be manipulated by a user; a first joint unit  400  being connected and disposed between the fixing structure  100  and the handling unit  300  to cause joint motion or the like of an end effector  600  (to be described below) according to the user&#39;s manipulation of the handling unit  300 ; a second joint unit  500  to allow the end effector  600  to carry out joint motion or the like in cooperation with the first joint unit  400 ; and the end effector  600  being connected to one end of the shaft  200  via the second joint unit  500  to perform surgery by using surgical tools (not shown) or functioning itself as a surgical tool. 
         [0022]    First, the shaft  200  may include a cavity therein to support and pass at least one wire (not shown) or torque transmission member (not shown), in the same manner as those of the minimally invasive surgical instruments disclosed in the aforementioned Korean patent applications of the applicant(s). (The torque transmission member is mainly intended for rolling motion of the end effector  600 , while the shaft  200  may function itself as the torque transmission member in some cases.) The shaft  200  may comprise at least one segment as necessary. Further, the shaft  200  may comprise a bend in at least a part thereof. 
         [0023]    Next, the handling unit  300  may control joint motion, rolling motion, opening/closing motion and the like of the end effector  600  according to the user&#39;s manipulation, in the same manner as those of the minimally invasive surgical instruments disclosed in the aforementioned Korean patent applications of the applicant(s). To allow for such control, the at least one wire or torque transmission member may be connected to the handling unit  300 . 
         [0024]    Next, the first and second joint units  400  and  500  may act together with the at least one wire or torque transmission member to allow the end effector  600  to carry out joint motion, rolling motion and the like, in the same manner as those of the minimally invasive surgical instruments disclosed in the aforementioned Korean patent applications of the applicant(s). 
         [0025]    Next, the end effector  600  may carry out joint motion, rolling motion, opening/closing motion and the like by the action of the at least one wire or torque transmission member passing from the handling unit  300  to the second joint unit  500  via the first joint unit  400  and the shaft  200 , in the same manner as those of the minimally invasive surgical instruments disclosed in the aforementioned Korean patent applications of the applicant(s). The tip of the end effector  600  may be implemented in the form of a clamp, a grasper, a pair of scissors, a stapler, a needle holder, a hook-type electrode or the like. 
         [0026]    Finally, the fixing structure  100  may hold a wire for controlling joint motion or the like of the end effector  600  so that the state of the joint motion of the end effector  600  may be firmly fixed. 
         [0027]      FIG. 2  is a partial cross-sectional view of the minimally invasive surgical instrument shown in  FIG. 1 . The fixing structure  100  will be discussed below with further reference to  FIG. 2 . 
         [0028]    The fixing structure  100  may comprise a spring  110  (preferably in the form of a coil). Further, the fixing structure  100  may comprise a wire guide path (e.g. a groove or pipe) extending from the handling unit  300  via the first joint unit  400 , or may further comprise a wire fixing assistance member  111  that may support the wire and assist it to be fixed. (In connection with one exemplary shape of the wire fixing assistance member  111 , reference may be made to  FIG. 3 .) The spring  110  may surround the outer surface of the wire fixing assistance member  111 . 
         [0029]    One end of the spring  110  may be connected to a rotational motion member  112 . Further, the other end of the spring  110  may be fixed to a case  114  or the like to be described below. Accordingly, a part of the spring  110  is rotated when the rotational motion member  112  carries out rotational motion, so that the spring  100  may be twisted on the whole. The rotational motion member  112  may contact a linear motion member  113 . The above components may be disposed within the case  114 , which surrounds and covers them. 
         [0030]      FIG. 3  is a partial cross-sectional view of the fixing structure  100  shown in  FIG. 2 . Further reference will be made to  FIG. 3 . 
         [0031]    The rotational motion member  112  may comprise a slope  112   a  at the portion contacting the linear motion member  113 , and the linear motion member  113  may also comprise a slope  113   a  at the corresponding portion. Thus, when the slope  113   a  applies a force to the slope  112   a  by the action of the linear motion member  113  (e.g., the action in which the linear motion member  113  carries out linear motion toward the rotational motion member  112  according to the manipulation of the handling unit  300  and then the state of the motion thereof is fixed), the rotational motion member  112  may rotate so that the spring  110  may be rotated and twisted. The slope directions of the two slopes  112   a  and  113   a  may be determined such that the spring  110  is rotated and twisted according to the rotation of the rotational motion member  112 . In case of  FIG. 3 , the slope directions of the slopes  112   a  and  113   a  are determined as illustrated because the spring  110  is rotated and twisted when the rotational motion member  112  rotates counterclockwise (as seen from the linear motion member  113 ). 
         [0032]    When the spring  110  is rotated and twisted by the action of the linear motion member  113  and the rotational motion member  112 , an internal space of the portion where the spring  110  surrounds the outer surface of the wire fixing assistance member  111  may be reduced. The spring  110  may accordingly tighten the wire fixing assistance member  111  and further the wire guided or supported by the wire fixing assistance member  111 , so that the wire may be fixed. 
         [0033]      FIG. 4  is a perspective view of a fixing structure  100  according to another embodiment of the invention. Further,  FIG. 5  shows a C-shaped ring  120  among the components of the fixing structure  100  shown in  FIG. 4 . According to the present embodiment, the C-shaped ring  120  is employed instead of the spring  110  so that an internal space of the portion where it surrounds a wire fixing assistance member  121  may be reduced, thereby fixing the wire. 
         [0034]    The C-shaped ring  120  according the present embodiment (preferably a plurality of the C-shaped rings  120 ) may surround the wire fixing assistance member  121 . The C-shaped ring  120  may comprise protrusions  120   a  at both ends thereof, and the protrusions  120   a  may be disposed in a groove  123   a  formed in a linear motion member  123 . As illustrated, the groove  123   a  may be formed (preferably in the form of a wedge or similar shape) such that an interval between the protrusions  120   a  is reduced by the action of the linear motion member  123  (e.g., when the linear motion member  123  carries out linear motion toward the shaft  200 ) to allow the C-shaped ring  120  to tighten the wire fixing assistance member  121 . Therefore, the present embodiment may also fix the wire as in the above-described embodiment. Meanwhile, the portions of the C-shaped ring  120  and the wire fixing member  121  except the protrusions  120   a  may be covered by covers  122   a  and  122   b,  and one end of the wire fixing assistance member  121  (represented as a cuboid-like shape in  FIG. 4 ) may allow the wire fixing assistance member  121  to be fixed to the covers  122   a  and  122   b  to a certain degree. 
         [0035]      FIG. 6  is a perspective view of a fixing structure  100  according to yet another embodiment of the invention. According to the present embodiment, a spring  130  is employed wherein a linear motion member  132  acts on both ends thereof so that an internal space of the portion where the spring  130  surrounds the outer surface of a wire fixing assistance member  131  may be reduced, thereby fixing the wire. 
         [0036]    The spring  130  according to the present embodiment may surround the outer surface of the wire fixing assistance member  131 . Protrusions  130   a  may be formed at both ends of the spring  130 . Meanwhile, the linear motion member  132  may comprise a front groove  133  and a rear groove  134  to allow the linear motion member  132  to act on the protrusions  130   a  of the spring  130  when it carries out linear motion toward the shaft  120 , so that the spring  130  may tighten the wire fixing assistance member  131 . (The protrusions  130   a  may be inserted in the front and rear grooves  133  and  134 .) As illustrated, the front and rear grooves  133  and  134  may be formed to be inclined with respect to the direction in which the linear motion member  132  carries out linear motion toward the shaft  200 , and to have the opposite inclinations. Therefore, the present embodiment may also fix the wire as in the above-described embodiments. 
         [0037]      FIG. 7  is a perspective view of a fixing structure  100  according to still another embodiment of the invention. Further,  FIG. 8  is a perspective view of a wire fixing assistance member  141  among the components of the fixing structure  100  shown in  FIG. 7 . According to the present embodiment, a spring  140  is employed wherein the spring  140  is twisted by means of two rotational motion members  143  and  144 , which are connected to both ends of the spring  140 , by the action of a linear motion member  142  so that an internal space of the portion where the spring  140  surrounds the outer surface of the wire fixing assistance member  141  may be reduced, thereby fixing the wire. 
         [0038]    The spring  140  according to the present embodiment may surround the outer surface of the wire fixing assistance member  141 . Both ends of the spring  140  may be connected to the first and second rotational motion members  143  and  144 , respectively. Therefore, when the first and second rotational motion members  143  and  144  rotate in the opposite directions, the spring  140  may accordingly be twisted. Meanwhile, the first and second rotational motion members  143  and  144  may comprise protrusions  143   a  and  144   a,  respectively. 
         [0039]    Further, the linear motion member  142  may be further provided. The linear motion member  142  may comprise a first slope  142   a  and a second slope  142   b.  The first and second slopes  142   a  and  142   b  may be respectively inclined in a direction to enable the first and second rotational motion members  143  and  144  to carry out the rotational motion as above. (Correspondingly, the protrusions  143   a  and  144   a  may also comprise slopes.) 
         [0040]    Accordingly, when the linear motion member  142  carries out linear motion toward the shaft  200 , for example, the first slope  142   a  applies a force to the protrusion  143   a  to allow the first rotational motion member  143  to rotate clockwise (as seen from the handling unit  300 ), and the second slope  142   b  applies a force to the protrusion  144   a  to allow the second rotational motion member  144  to rotate counterclockwise. Therefore, the present embodiment may also fix the wire as in the above-described embodiments. Meanwhile, as illustrated in  FIG. 8 , the wire fixing assistance member  141  may comprise a spring fixing unit  141   a,  which may prevent the spring  140  from unnecessarily moving toward the shaft  200  or in the opposite direction or the like. A component such as the spring fixing unit  141   a  may also be used in the above other embodiments employing a spring. 
       Applications 
       [0041]    According to an application of the present invention, those skilled in the art may partially change the form and such of the handling unit or the like so that the wire or torque transmission member of the minimally invasive surgical instrument may be operated or fixed by an electric motor or the like of another motor-based system (not shown) such as a surgical robot, as necessary. 
         [0042]    Although the present invention has been described in terms of specific items such as detailed components 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 those skilled in the art that various modifications and changes may be made from the above description. 
         [0043]    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.