Abstract:
A guide wire placement and removal tool is provided that includes a handle mounted to a shaft connected to a wire engagement mechanism disposed opposite the handle. The mechanism includes a housing aligned with the shaft to enable the wire to pass therethrough, and a moveable engagement member biased into a locking position within the housing to engage a wire positioned therein. The mechanism also includes a release member that can be selectively engaged with the engagement member to disengage the engagement member from the wire to allow the wire to move with regard to the tool. Once the release member is released, the engagement member is biased back into a locking engagement with the wire to securely hold the wire within the tool.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from U.S. Provisional Patent Application Ser. No. 60/036,195 filed on Mar. 13, 2008, the entirety of which is expressly incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to surgical tool, and more specifically to a tool capable of placing and removing guide wires utilized in surgical procedures. 
     BACKGROUND OF THE INVENTION 
     In many surgical procedures, screws or other types of fasteners are utilized to hold pieces of a patient&#39;s anatomy together in conjunction with other structural pieces, such as plates or flanges. When using these screws or other fasteners in these procedures, it is imperative that the fasteners be properly positioned in order to achieve the proper result from the procedure. Thus, often the physician will use wire guides to indicate where a particular fastener will be positioned prior to actually securing the fastener to the patient to ensure that the fastener is in the proper location. 
     To utilize these guide wires, a number of different types of devices are employed to properly hold the wires while the wires are positioned within the patient, as well as to engage or remove the wires from the patient. However, prior art devices used for this purpose utilize complex locking mechanisms to securely hold the wire, such as three jaw collets, or rotatable chucks, which can often make the tools difficult to use, especially during delicate surgical procedures. 
     Therefore, it is desirable to develop a tool that can be used to hold, engage and remove the wire that includes a wire engagement mechanism that enables the wire to be either grasped and held or released by the tool in a simple and easy to employ manner. 
     SUMMARY OF THE INVENTION 
     According to a one aspect of the present invention, a tool for releasably engaging a surgical guide wire is provided that includes a wire engagement mechanism having a single release member that is biased to engage a guide wire passing through the tool. To release the wire when desired, the engagement mechanism is simply pressed inwardly with regard to the remainder of the tool, and thereby disengaged from the wire. Also, due to the biasing force exerted on the engagement mechanism, the mechanism can be disengaged from the wire using only one hand, thereby allowing the physician to hold and steady the tool with the remaining hand. Also, the tool can be simultaneously held and have the engagement mechanism disengaged from the wire with only one hand, allowing the physician to use the remaining hand to perform some other function. 
     According to another aspect of the present invention, the engagement mechanism on the guide wire tool can be adjusted to provide different levels of biasing force to the engagement mechanism. As a result, the tool can be configured for use in a particular procedure, and for use with particular wires or other structures to be used in the procedure. This is particularly useful when the tool is also employed to drive and/or remove the guide wire, such that the engagement mechanism can securely hold the wire as the tool is used to move the wire with respect to the patient. 
     Numerous other aspects, features, and advantages of the present invention will be made apparent from the following detailed description together with the drawings figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings illustrate the best mode currently contemplated of practicing the present invention. 
       In the drawings: 
         FIG. 1  is an isometric view of a guide wire positioning tool including the wire engagement mechanism constructed according to the present invention; 
         FIG. 2  is an exploded view of the tool and engagement mechanism of  FIG. 1 ; and 
         FIG. 3  is a cross-sectional view along line  3 - 3  of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference now to the drawing figures in which like reference numerals designate like parts throughout the disclosure, a guide wire positioning tool constructed according to the present invention is indicated generally at  100  in  FIGS. 1 and 2 . The tool  100  includes a handle  102  mounted to one end of a shaft  104  that is secured opposite the handle  102  to a wire engagement mechanism  106 . The handle  102  has a through-bore  103  that is disposed around the shaft  104  to mount the handle  102  to the shaft  104 . The handle  102  can have any desired shape in order to make the handle  102  easy to hold and manipulate, and is preferably mounted to the shaft  104  such that the handle  102  can freely slide and/or rotate along the shaft  104  to provide a “tapping” function when a guide wire  108  engaged by the tool  100  is to be driven into or removed from a patient. However, it is also contemplated that the handle  102  can be fixed to the shaft  104 , when desired, or removably attached to the shaft  104  to enable handles  102  of varying configurations to be secured to the shaft  104  to enable the tool  100  to be utilized in varying situations and environments. 
     Looking now at  FIGS. 1 and 2 , the drive shaft  104  is essentially formed as a hollow tube with a central passage  110  through which the wire  108  can pass. Also, depending upon the manner in which the handle  102  is attached to the shaft  104 , the shaft  104  can have a pair of stops  112 ,  114  disposed at opposite ends  116 ,  118  of the shaft  104 , such that the handle  102  is maintained on the shaft  104  between the stops  112 ,  114  when slidably mounted to the shaft  104 . Additionally, the stops  112 ,  114  are preferably positioned inwardly from the ends  116 ,  118  of the shaft  104 , so that one of the ends  116 ,  118  can be utilized to secure the shaft  104  to the wire engagement mechanism  106 . 
     Referring now to  FIGS. 1-3 , the wire engagement mechanism  106  includes a housing  120  that defines a channel  122  therethrough. The channel  122  includes a pair of opposed end sections  124 ,  126  located at opposite ends of the housing  120 , and a central section  128  disposed between the end sections  124 ,  126 . 
     Each end section  124 ,  126  is generally circular in cross section along the longitudinal axis of the housing  120 , with an inwardly tapering portion  130  located immediately adjacent the central section  128 . The end sections  124 ,  126  each house a ferrule or collet  132  and a spring member  134 . The collet  132  is formed with a wide end  136  defining a flange  138 , and a narrow end  140 . The narrow end  140  includes a number of apertures  142  formed therein in which are disposed bearings  144 , which are preferably circular ball bearings. The apertures  142  intersect a bore  146  that extends completely through the collet  132  and is positioned in alignment with the channel  122  of the housing  120  when the collets  132  are disposed in the end sections  124 ,  126 . The narrow end  140  of each collet  132  has a diameter that enables the narrow end  140  to pass through the tapering portion  130  of each end section  124 ,  126  and partially into the central section  128 . Also, opposite the wide end  136 , the narrow end  140  has a sloped surface  148  surrounding the bore  146 . 
     The spring members  134  are preferably coil springs that each defines a passage  149  therethrough that is aligned with the bore  146  in the collet  132  and the channel  122  in the housing  120 . Further, the springs  134  are each disposed in engagement with the flange  138  on the wide end  136  of the adjacent collet  132 , and are in contact opposite the collet  132  with either the end  118  of the shaft  104  engaged with the housing  120 , or with an end cap  150  engaged with the housing  120  opposite the shaft  104  and including a central passage  151  therein disposed in alignment with bore  103 , channel  122 , bores  146 , and passages  149 . The end  118  of the shaft  104  and the end cap  150  can be adjusted within the channel  122  to alter the amount of compressive force exerted on the spring members  134 , thereby altering the amount of force required to move the collets  132  against the bias of the springs  134 . This is preferably accomplished by making the end cap  150 , movably and more preferably threadedly engageable within the channel  122  in the housing  120 , such that any additional turning of the end cap  150  into or out of the channel  122  will correspondingly affect the compressive force from the spring  134  acting against movement of the collet  132 . The end  118  of the shaft  104  can also be adjusted within the channel  122  in any suitable manner to affect the compressive force of the adjacent spring member  134  in a similar manner, if desired. 
     Within the central section of the channel  122  is disposed a plunger  152 . The plunger  152  has a lower portion  154  that corresponds generally in shape to the cross section of the central section  128 , such that the lower portion  154  can guide the movement of the plunger  152  within the central section  128 . The plunger  152  also includes a central portion  156  that is narrower in diameter than the lower portion  154  and that defines an aperture  158  therein that can be positioned in alignment with the through-bore  103 , the bores  146  in the collets  132 , the passages  149  in the spring members  134 , the passage  151  in end cap  150 , and the channel  122  in the housing  120 . 
     Opposite the lower portion  154 , the central portion  156  is connected to an upper portion  160  that has a diameter similar to that of the lower portion  154  and an inwardly tapering wall  162  extending to the central portion  156 . The upper portion  160  extends outwardly from the central section  128  of the channel  122  and includes a pair of opposed flanges  164  defining a notch  166  therebetween. Each flange  164  includes an opening  168  therein that receives one end of a pin  170  positioned across the notch  166  to movably secure a release member or trigger  172  to the plunger  152 . 
     The trigger  172  includes a first end having a bore  174  formed therethrough and in which a pivot pin  176  is disposed. The pivot pin  176  is affixed at opposite ends within a passage  178  formed in the housing  120  in a direction generally perpendicular to the channel  122 . The passage  178  crosses a recess  179  formed in the housing  120  above, and in alignment with the channel  122 , and in which the trigger  172  is partially disposed to provide the trigger  172  and tool  100  with a reduced cross-sectional profile to enhance the ease of operation of the tool  100 . Opposite the pivot pin  176 , the trigger  172  extends outwardly from the recess  179 , including a pin opening  180  through which pin  170  extends to connect the trigger  172  to the plunger  152 , and an engagement portion  182  located opposite the pivot pin  176 . 
     In operation, initially the engagement portion  182  of the trigger  172  is pressed towards the housing  120 , thereby urging the plunger  152  into the central section  128  of the channel  122 . This, in turn, causes the inwardly tapering wall  162  on the upper portion  160  to engage the sloped surfaces  148  on each collet  132 . When the force exerted on the trigger  172  and plunger  152  is sufficient to overcome the force exerted by the spring member  134 , the upper portion  160  of the plunger  152  urges the collets  132  out of the central section  128  against the bias of the spring members  134 . As the collets  132  are moved in this direction, the ball bearings  144  can move out of the apertures  142  as the end sections  124 ,  126  of the channel  122  widen from the inwardly tapering portion  130 . When the collet  132  has been moved a sufficient distance within the end sections  124 ,  126  to displace the bearings  144  sufficiently out of the bore  146 , the wire  108  can be inserted completely through the tool  100 , namely through the bore  103  in the shaft  104 , the bores  146  in the collets  132 , the passages  149  in the spring members  134 , the passage  151  in the end cap  150 , and the aperture  158  in the plunger  152 . When the trigger  172  is released, the spring members  134  urge the collets  132  back into the central section  128 , causing the bearings  144  to move along the tapering portions  130  of the end sections  124 ,  126  and to re-enter the apertures  142 , consequently engaging the wire  108  therein. This engagement between the bearings  144  and the wire  108  securely retains the wire  108  at that position with regard to the tool  100 , such that the wire  108  can be driven into or removed from the patient in any suitable manner, such as by using a handle  102  slidably mounted to the shaft  104 . 
     When it is desired to remove the wire  108  from the tool  100 , or to adjust the position of the wire  108  with regard to the tool  100 , or vice versa, the trigger  172  is again depressed towards the housing  120  to effect the displacement of the collets  132  and bearings  144  in the manner described previously, such that the bearings  144  no longer contact the wire  108 , which can then move freely through the entire tool  100 . 
     In addition, when the wire  108  is securely engaged by the bearings  144 , when the handle  102  is slidably mounted to the shaft  104 , the tool  100  can be utilized to adjust or drive the wire  108  into the desired position. This is accomplished by sliding the handle  102  away from the housing  120 , and subsequently driving the handle  102  towards the housing  120 , where the handle  102  forcefully strikes the stop  114 . The force of the handle  102  striking the stop  114  is transmitted through the housing  120 , to which the stop  114  is connected, and onto the wire  108  to urge the wire  108  into the substrate within which it is positioned. This “tapping” motion can be repeated by the individual to move the wire  108  into the desired position, at which point the tool  100  can be disengaged from the wire  108  in the manner described previously and removed from the wire  108 . 
     With regard to each of the components of the tool  100 , because the tool  100  is utilized in surgical procedures, the components are each preferably formed from fluid-impervious and sterilizeable materials, such as stainless steel or other suitable materials well known to a person of ordinary skill in the art. Further, the tool  100  can be constructed with only a single collet  132  and spring  134  used to engage the wire  108 . Also, in addition to wires, the tool  100  can be utilized to engage and position other elongate members within other substrates. 
     Various other embodiments of the present invention are contemplated as being within the scope of the filed claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.