Abstract:
A locking device for use in a trocar inserted into a body cavity. The locking device include various operating components that may be easily manipulated and recognized by a surgeon during complicated surgery, and a locking portion secured in the trocar. The locking portion may include internal threads formed only on a head, a cam operated element, resilient fingers, a collet-type locking device, or a frictional detent or opening, quickly moved into a locking position against any type of instrument passing through the trocar into the body cavity. The portion of the locking device contacting the instrument must be sized and dimensioned to provide a firm grip in the locking position, without damaging or marring the instrument against which it is locked.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to trocars for use in endoscopic surgery, and, more particularly, to locking devices for securing in position an instrument inserted through a trocar into a body cavity, so as to prevent movement of the instrument. 
     2. Description of Related Art 
     As is well known, surgical devices, such as trocars, are widely used in endoscopic surgery. Trocars are devices that are used to provide access to a surgical site within a selected cavity in a patient&#39;s body. A trocar is typically inserted through a small skin incision by pressing the distal end of the trocar against the outer skin of the patient with sufficient force applied to the trocar handle, so that the piercing tip of an obturator effectively penetrates the patient&#39;s skin and underlying fat tissue, fascia, muscle and into a selected internal cavity. The trocar obturator is removed, and the trocar cannula is then used as a passageway to and from the patient&#39;s body cavity. During many procedures, a number of trocars are required so that a number of passageways are formed into the selected body cavity, to enable a surgeon to concurrently use an endoscope and one or more other devices inserted into the body cavity. 
     An example of a known trocar is shown in U.S. Pat. No. 5,256,149 to Banik et al. This patent discloses a trocar constructed from a transparent plastic material, and includes a trocar cannula with a cannula handle, a cannula tube and a trocar obturator passing through the handle and tube. The device also includes a gas inlet, having a valve thereon to enable a gas to be used to insufflate and desufflate a body cavity into which the trocar cannula has been inserted and is held, as well as a handle to operate an interior flap valve to release gas pressure in the trocar. After the obturator is used to pierce a person&#39;s body and form an opening into an underlying body cavity, the trocar cannula may be threaded into the opening formed into the body cavity with a stability thread to aid in securing the trocar cannula in place. The obturator is removed from the trocar cannula, and an instrument, such as an endoscope, an endoscopic needle grasper, a holding device, a manipulating device, or the like, may be inserted through the trocar cannula into the body cavity. 
     During many types of surgery, a number of trocars are inserted so that there are a number of passageways into the selected body cavity. One or more of these passageways may be used to move or position an organ if a further portion thereof must be seen or operated on. In addition, the organ may cover or block another organ, which needs to be examined or operated on. This is usually accomplished by the insertion of a grasping or manipulating device or instrument, into a passageway in one of the trocars. However, the grasping or manipulating instrument is usually loosely aligned in the trocar passageway, and must be held in position or somehow secured, so that any organ, or the like, that is pressing against or supporting, does not move or shift. Since the surgeon and/or assistant must concentrate on specific steps and requirements during a surgical procedure, and often need both of their respective hands, a holding means or another person must help to hold or support the grasping or manipulating device. Often, however, it is left to the surgeon or assistant to try to hold the instrument steady by the use of a surgical clamp between the instrument and a surgical drape on the patient, or somehow jury-rig a means to hold or support the instrument. For numerous reasons, surgeons and their assistants have difficulty in fully or properly holding or supporting such grasping or manipulating device, and problems have occurred. Therefore, a need exists for a simple and effective means for holding a grasping or manipulating device or instrument in place in a trocar during surgical procedures, such as endoscopic surgery. 
     In my U.S. Pat. No. 5,662,613 (“&#39;613”), entitled “Endoscopic Instrument Lock”, there is described and shown a locking device for use in holding an instrument in place in a trocar. This locking device is preferably metallic, and includes an enlarged head that may be easily grasped and recognized by a surgeon during surgery. The device has an elongated shaft portion with self-taping threads formed thereon, secured to the enlarged head. The outer end of the elongated shaft is blunt and soft to prevent damage or marring of an instrument against which it is pressed. The elongated shaft is inserted into the existing gas opening in the wall of the trocar and the enlarged head turned so that the self-tapering threads are threaded into the existing gas opening to lock the device into position with the blunt, soft end against an instrument. The enlarged head is preferably knurled, roughened or serrated to enable the locking device to be easily grasped and turned by the fingertips of a user. The spherical head is also preferably made from or covered with a phosphorescent material so as to be more easily seen in low lighting conditions. Although this locking device has provided significant improvement in the art, there is a possibility that if it is carelessly handled or manipulated, foreign or toxic material might be dislodged or inserted into the gas opening and enter a body cavity of a patient. 
     Furthermore, the locking device of the &#39;613 patent must be stored before or after use, and is not always immediately available for use, unless placed in the gas opening of the trocar or trocars, before, during or after being inserted into a body cavity. 
     Therefore, there still exists a need in the art for easy to use and readily available locking devices for instruments inserted into a trocar, and, in particular, locking devices that are not easily laid aside or misplaced. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is a general object of the present invention to provide an improved instrument locking means. It is a particular object of the present invention to provide an improved instrument-locking device, which is easy to manufacture and use. It is another particular object of the present invention to provide an improved instrument-locking device, which is readily available for use with a trocar. It is yet another particular object of the present invention to provide an improved instrument-locking device, which is formed with or in a trocar. It is a further object of the present invention to provide an improved instrument-locking device, which is readily available and easily operated in a darkened operating room. It is yet another object of the present invention to provide an improved locking device held in a trocar, which locking device is capable of being manufactured with the trocar. And, it is still another particular object of the present invention to provide an improved locking means for trocars, which are secured to the trocar and cannot be misplaced or lost. 
     In accordance with one aspect of the present invention, there is provided a locking element for a trocar, to hold an instrument in place. The locking element is quickly and easily operated, and is held in the trocar, where it may be easily grasped and used by a surgeon or assistant during surgery. The locking element is held in position in the trocar so as to lock an instrument inserted into the trocar, without fumbling or searching for the locking device. The locking device cooperates with the instrument in the trocar, without damaging or marring the instrument. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings, wherein like reference numerals are used throughout the several views, and, in which: 
     FIG. 1 is a perspective view of a prior art trocar inserted into a body cavity with a grasping or manipulating instrument inserted through the trocar into a body cavity, and also showing a first embodiment of the locking device of the present invention, held in a gas opening before it is locked into position in the trocar for locking the instrument in position, and preventing movement thereof; 
     FIG. 2 is a top plan view of a second embodiment of a locking device built into a trocar for locking instrument in the trocar; 
     FIG. 3 is an enlarged cross-sectional view taken along line  3 — 3  of FIG. 2; 
     FIG. 4 is a partial cross-sectional view of a trocar with a grasping or manipulating instrument inserted therein, having a third embodiment of a locking device held in the trocar and in position to be pressed down to lock the instrument in position; 
     FIG. 5 is a partial cross-sectional view, similar to FIG. 4, with the locking device in the locking position around the instrument; 
     FIG. 6 is a partial cross-sectional view of a trocar with a grasping or manipulating instrument inserted therein, and passing through a fourth embodiment of the locking device, in the form of a collet-type lock; 
     FIG. 7 is a cross-sectional view taken along line  7 — 7  of FIG. 6; 
     FIG. 8 is a partial cross-sectional view of a trocar with a grasping or manipulating instrument inserted therein and having a fifth embodiment of the locking device in a locking position against the instrument; and 
     FIG. 9 is a partial cross-sectional view, similar to FIG. 8, with the locking device in an open or unlocked position to allow the instrument to move therein. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to described instrument locking devices or means, identified generally at  10 ,  12 ,  14 ,  18 ,  20  for use in trocars, such as  22 ,  24 ,  26 ,  28 ,  30 . For example, locking device  10  may be inserted in an existing gas opening  32  in the trocar  22  to hold or lock an instrument, such as  34 , with respect to the trocar. For reasons of explanation only, and not by way of limitation, the locking device  10  is described and shown herein for use in a specific trocar, such as described and claimed in U.S. Pat. No. 5,256,149 (“&#39;149”) to Banik et al., having a transparent plastic body. The relevant portions of this &#39;149 patent are incorporated herein, in their entirety, by this reference thereto. It is to be understood, that the present invention provides locking devices or means for use in any existing trocar or similar surgical instrument, and which may be inserted or built into any such surgical instrument, requiring a means or locking device to hold an instrument inserted therein in an immovable or locked position during surgery. 
     Since only one of the gas inlets of a plurality of trocars must be used to insufflate and desufflate the internal body cavity, if a plurality of trocars are inserted into a selected body cavity, one or more of the other gas inlets may be provided with a locking means  10  inserted therein. 
     As shown in FIG. 1 of the drawings, after a trocar cannulas  22  has been inserted through a skin layer, etc.  36 , so as to be connected to an internal cavity  38  and an obturator (not shown) removed in a manner well known to those skilled in the art, the instrument  34  is inserted through a passage in the trocar. After the instrument  34  is inserted and moved or manipulated to a preferred or selected position, the locking means  10  may be turned so as to lock the instrument against further movement, with respect to the trocar. The further locking means  12 ,  14 ,  18  and  20 , described below, are also operated to lock the instrument  34 . The locking of instrument  34  frees up the hands of a surgeon, or the surgeon&#39;s assistant, to perform the rest of the surgical procedure through one or more other trocars, not shown, in an expeditious and safe manner. 
     The locking device or element  10  has an actuating or operating element  40 , such as an enlarged head, with a plurality of grasping elements or vanes  42 . The head  40  is secured to an elongated shaft  44 . A lower end  46  has an internally formed ramp, threads, or the like,  48  formed therein, so as to form a locking element that is termed a “Luer-type Lock”. The “Luer-type Lock”  48  allows the operating element  40  to be easily operated by turning, so that the “Luer-type Lock” moves over an outer end or lip  50  of the gas opening  32 , in a manner well known to those skilled in the art. By using a Luer-type lock, the danger of toxic material entering the trocar  22  is substantially eliminated. 
     As disclosed in the &#39;149 patent, the housing of the trocar cannulas, including the valve and gas opening  14 , are manufactured from plastic. However, the locking device  10 , including head  40 , the shaft  44  and the lock  48  may be formed from any desired material, such as stainless steel, or other plastic or metal material. As is often the case, the material used may be coated or uncoated, as long as it may be easily sterilized and is approved for medical use. The selected material must also allow the locking element  10  to be quickly and easily engaged, when the Luer-type lock  48  is moved over the end  50 , by turning head  40 . The locking device  10  will, therefore, be quickly inserted and then turned, so that the locking element or shaft  44  moves downwardly or inwardly, into the gas inlet  32 , until the lower or outer end  52  is brought into contact with the instrument  34 . The outer end  52  is preferably blunt and softened, so that when it moves into contact with the instrument  34 , it will not damage, mar or mark the same, and so that it will have a larger contact surface which will frictionally engage instrument  34 , to prevent it from moving, with respect to the trocar  22 . 
     Turning now to FIGS. 2 and 3, there shown is a second embodiment of the locking device  12 , which is preferably added to or built into the trocar cannulas  24 . This locking device  12  includes an actuating or operating element  54 , such as a handle, held on the outside of the trocar  24 . The handle  24  is rotatably and sealingly held in an opening  56  in a first wall of trocar cannulas  24 , and is connected to, or formed integrally with a locking element  58 , such as an offset cam element, and a lower holding shaft  60 , which is also rotatably mounted within an opposite or second wall  62  of the trocar cannulas  24 . The offset cam element  58  is moved by turning the handle  54 , between an unlocked position, where it is spaced from the instrument  34 , as shown in broken line in FIG. 2, to a locked position, as shown in solid line in FIGS. 2 and 3, where the cam element  58  is pressed against the instrument  34  to lock the instrument and prevent it from moving. Arrow  64  in FIG. 2 indicates the direction of movement of the handle  54  from the open position (broken line) to the locked position (solid line). 
     Referring now to FIGS. 4 and 5, there shown is a third embodiment of the locking device  14 , which is preferably built into the trocar cannulas  26 . The locking device  14  includes an actuating or operating element  66 , such as a handle or push button, and a locking element having an open, partially curved or cylindrical central portion  68  and a pair of resilient arms or fingers  70 ,  72 . As shown, the operating element  66  is pressed downwardly or inwardly, from the position shown in FIG. 4, into the trocar cannulas  26 , to the position shown in FIG. 5, to lock the instrument  34  against movement. As the operating element  66  moves into the trocar cannulas  26 , angled inner sides  74 ,  76  of the resilient arms or fingers  70 ,  72  contact the instrument  34 . The arms or fingers are cammed or pushed outwardly by the instrument  34 , until the instrument enters open partially cylindrical central portion  68 , where the instrument is clamped, held or locked immovably in position, until the element  66  is pulled out or retracted. It is to be understood, that the open, partially curved or cylindrical central portion  68  and the resilient arms  70 ,  72 , as well as the angled sides  74 ,  76 , are sized and dimensioned so as to cooperate with instruments, such as  34 , which are inserted in trocars, to securely clamp, hold or lock the instrument in place when pushed onto or otherwise forced onto the instrument. Furthermore, the parts of the lower locking element must be sized and dimensioned to enable the resilient arms  70 ,  72  to be sufficiently withdrawn, to release the instrument  34  when element  66  is moved or withdrawn to its open position (FIG.  4 ). 
     FIGS. 6 and 7 show a still further or fourth embodiment of the locking device  18 , built into the trocar cannulas  28 . This locking device  18  is a collet-like device, which is formed in or around an entrance or exit opening of the trocar cannulas  28 . The locking device  18  includes a locking element or portion  78  having a plurality of resilient arms or fingers  80  (four are shown), with angled or tapered outside edges  82 , as shown in FIG.  6 . An actuating or operating element  84 , such as a handle or ring, having internal threads  86  is held on external threads  88  formed on an exterior surface of each of the fingers  80 , adjacent outer ends of the fingers. The turning ring  84  also includes an annular extending portion  90  formed therein, after the internal threaded portion  86 . The annular extending portion  90  includes an internal tapered wall  92 , which cooperates with the angled or tapered outside edges  82  of the fingers  80 . The collet-type locking device  18  is operable between an open position, as shown in FIG. 6, to a locking position, as illustrated in FIG. 7, by turning the handle or ring  84 . That is, when turned in one direction, the threads  86 ,  88  will cooperate to move the annular extending portion  90  inwardly or a first direction, to force the tapered wall  92  against the angled sides  82 , to move the fingers  80  inwardly, to clamp, hold or lock the instrument  34  in position. However, when turned in the other direction, the annular extending portion  90  will move outwardly, or in a second direction, to move the tapered wall  92  away from the angled sides  82  of the resilient fingers  80 , to thereby allow the resilient fingers  80  to move away or spring back from their locked position against the instrument. 
     Turning now to FIGS. 8 and 9, there shown is a fifth embodiment of the locking device  20 , which is preferably built into the trocar cannulas  30 . This locking device  20  includes a locking element  94 , such as a central element or portion having an aperture or opening  96  with a curved or semi-circular top portion  98  formed in the opening. The curved or semi-circular top portion  98  is sized and dimensioned to frictionally cooperate with and hold the instrument  34  in position, when biased or pressed against the same, as shown in FIG.  8 . The central element  94  is preferably sized and dimensioned and made from a material which will engage the instrument  34  with sufficient friction when the curved or semi-circular top portion  98  is biased or pressed against the instrument, to lock or prevent movement thereof. The locking element  94  is connected or secured to two aligned elements or shafts  100 ,  102 , at opposite ends or sides thereof. These shafts are inserted and sealingly held in openings  104 ,  106 , formed in opposite walls of the trocar cannulas  30 . A biasing means  108 , such as a spring  108  is mounted over the first shaft  100 , and normally biases the locking element  94  into the locked position, with the curved or semi-circular end  98  pressed against the instrument  34 , which is inserted in the opening  96 . An actuating or operating element is provided to open or unlock the locking device  20 , for insertion of instrument  34  into opening  96  or movement of the instrument within the trocar cannulas  30 . This actuating or operating element is comprised of an outer end  110  of shaft  102 , which is pressed or pushed inwardly toward the trocar, to compress the spring  108  and move semi-circular end  98  away from instrument  34 , as shown in FIG.  9 . 
     As described above, the locking devices  10 ,  12 ,  14 ,  18 ,  20  of the present invention are inserted into an existing gas opening in a trocar cannulas, or are added to or built into a trocar cannulas. The locking devices  10 ,  12 ,  14 ,  18  and  20  are then readily available and accessible to a surgeon or an assistant during a surgical procedure, for operating or tightening the same. The surgeon or the surgeon&#39;s assistance&#39;s hands are thereby left free for more important tasks. Because of their availability, size and easy operation, the locking devices of the present invention, may be conveniently operated in a trocar in critical situations without requiring any special tools, adjustments, or changes to existing equipment. Furthermore, the locking devices of the present invention are easily and quickly operated to lock or unlock an instrument, as needed. 
     Thus, it can be seen, that the locking devices of the present invention provide locks that are compatible with existing trocar cannulas and/or new trocar cannulas, and which are easily installed at a point-of-use, or by a manufacturer of trocars, at the factory when assembling the trocar cannulas. 
     Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.