Patent Publication Number: US-8992554-B2

Title: Guarded surgical knife handle

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional application of prior application Ser. No. 13/556,673, filed Jul. 24, 2012, which is a continuation application of prior application Ser. No. 12/620,262, filed Nov. 17, 2009 (now U.S. Pat. No. 8,256,331), which claims the benefit of U.S. Provisional Application No. 61/116,497, filed on Nov. 20, 2008, the contents of each being incorporated herein by reference. 
    
    
     SUMMARY 
     In particular embodiments of the present invention, a guarded surgical knife handle includes a handle portion with a blade holder, a chamber within the handle portion, and a slot. The guarded surgical knife handle also includes a guard having an open distal end slidably mounted within the handle portion that can slide longitudinally between an unguarded position and a guarded position. The guard is sized to surround the blade in the guarded position. The guarded surgical knife handle also includes a latch that latches the guard when the guard is slid into the guarded position and a first button that disengages the latch. The guarded surgical knife handle includes a bias member that forces the guard in a proximal direction to an unguarded position when the latch is disengaged along with a second button extending through the slot used to slide the guard in a distal direction into the guarded position. 
     In other embodiments of the present invention, a method for unguarding and guarding a surgical knife includes providing a guarded surgical knife with a handle portion including a blade and a slot. The guarded surgical knife also includes a guard having an open distal end slidably mounted within the handle portion. The guard is latched by a latch in a guarded position. The method also includes disengaging the latch using a button to allow a bias member to force the guard in a proximal direction. The method further includes sliding the guard to the guarded position to re-engage the latch. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a disassembled view of a guarded surgical knife handle according to a particular embodiment of the present invention; 
         FIGS. 2A and 2B  illustrate the guarded surgical knife handle of  FIG. 1  in a guarded and unguarded position, respectively; and 
         FIG. 3  is a flow chart showing an example method of unguarding and guarding a surgical knife according to a particular embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     For purposes of this description, the following conventions are employed in naming various locations of the guarded surgical knife handle. “Longitudinal” describes a direction generally along an axis between one end of the guarded surgical knife that holds a blade in proximity to a patient and the opposite end near the surgeon. “Proximal” describes a location relatively closer to the surgeon than the patient in the longitudinal direction; conversely, “distal” refers to a location that is closer to the patient. “Upper,” “lower,” “top,” and “bottom” describe locations in terms of the orientation of the guarded surgical knife handle as it is held by a surgeon to perform incisions on a patient. “Vertical” describes a direction generally along an axis between the top and bottom of the guarded surgical knife handle, while “height” measures a distance in a vertical direction. “Lateral” describes a direction generally along an axis perpendicular to the longitudinal and vertical directions, corresponding generally to left and right directions from the surgeon&#39;s perspective. 
       FIG. 1  illustrates a disassembled view of various components of a guarded surgical knife handle  100  according to a particular embodiment of the present invention,  FIG. 2A  is a cross-section of the assembled guarded surgical knife  100  in a guarded position, and  FIG. 2B  is a cross-section of the guarded surgical knife  100  in an unguarded position. The guarded surgical knife handle  100  includes a guard  200  with an open distal end  202  slidably mounted in a chamber formed within a handle portion  300  (shown in two pieces in  FIG. 1 ). The handle portion  300  includes a blade holder  302  adapted to hold a blade  304 . 
     The blade  304  may be any sort of blade suitable for surgical incisions and may have a straight or curved edge. In various embodiments of the present invention, the blade  304  may be straight or may be inclined at a particular height and angle (as depicted in  FIG. 1 ), and the guarded surgical knife handle  100  may have colored portions according to a predetermined color code to indicate the type of blade for the guarded surgical knife handle  100 . The guard  200  is sized appropriately for the particular type of blade  304 , which may be done, for example, by increasing the height of the guard  200  at the open distal end  204 . A notch  301  sized to receive the portion of the guard  200  having a greater height may be provided in the handle portion  300 . The relative height of the blade holder  302  above a bottom of the lower handle portion  300  may also be selected to facilitate use of the blade  304  during surgery and to easily fit the guard portion  202  around the blade  304 . For example, a blade holder  302  used to hold a straight blade might hold the point of blade at a height approximately in the middle of guarded surgical knife, while a blade holder  302  for a blade with a larger height might be placed at the bottom of the lower handle portion  300 . 
     The guard  200  may also include additional safety features to further reduce the likelihood of inadvertent contact with the blade  304 . For example, if the guard  200  has a height and/or width sufficiently large to admit a finger at the open distal end  202 , the guard  200  may include narrowing features such as internal ribs (not shown) to prevent the finger from entering the guard  200 . The guarded surgical knife handle  100  may also include features to prevent the guard  200  from being displaced so as to contact the blade  304 . The guard  200  may also be advantageously configured to allow the surgeon to more easily visualize the blade  304 . For example, the guard  200  may be formed partially or entirely from a transparent material, so that the surgeon can see the blade in both the guarded and unguarded positions. 
     The guarded surgical knife handle  100  includes a latch  204  and a bias member  206 . The latch  204  holds the guard  200  in a guarded position, while the bias member  206  forces the guard  200  in a proximal direction when the latch  204  is disengaged. In the depicted embodiment, the bias member  206  is a coil spring, but other suitable mechanical arrangements for forcing the guard  200  in the proximal direction could also be used. In the guarded position, the latch  204  is held against a detent  310  by the force of the bias member  206 . A button  306  is depressed to push the latch  204  down below the detent  310 , thus disengaging the latch  204  and allowing the guard  200  to slide in the proximal direction due to the force exerted by the bias member  206 . 
     To return the guard  200  to the guarded position, a second button  308  is provided that extends through a slot  309  in the handle portion  300 . The second button  308  is used to slide the guard  200  back into the guarded position. As the guard  200  slides forward, the latch  204  is pushed down by the detent  310 . Once the latch  204  passes the detent  310 , the latch  204  pops up to rest behind the detent  310 , thus re-engaging the latch  204  and latching the guard  200  in the guarded position. Although a particular embodiment of the latch mechanism has been described, other alternative embodiments will be readily apparent to one skilled in the art. For example, the button  306  could be a trigger beneath the guarded surgical knife handle  100  that lowers a detent latching the guard  200  in place. In general, any suitable mechanism for holding the guard  200  in place against the force exerted by the bias member  206  may be used for the latch  204 . 
     The buttons  306  and  308  may include textured surfaces to facilitate gripping the guarded surgical knife handle  100  and to provide a tactile indication of the location of the buttons  306  and  308 . Additionally, a bottom grip feature (not shown) may be extend from the bottom of the handle portion  300  to allow a secure finger hold and to permit the surgeon to hold the guarded surgical knife handle  100  more securely while the button  308  is being slid. The bottom grip feature may advantageously include a flattened bottom surface that prevents the guarded surgical knife handle  100  from rolling when it is set down on a level, flat surface. A textured grip surface may also be placed adjacent to the bottom grip feature to make the surgeon&#39;s grip on the guarded surgical knife handle even more secure. 
       FIG. 3  is a flow chart  400  illustrating an example method of unguarding and guarding a guarded surgical knife handle  100  according to a particular embodiment of the present invention. At step  402 , a guarded surgical knife handle  100  is provided with the latch  204  engaged. At step  404 , the latch  204  is disengaged by pressing the button  306 , thus allowing the bias member  206  to force the guard  200  proximally into an unguarded position. At step  406 , the guard  200  is slid using the button  308  back into the guarded position, thus re-engaging the latch  204 . 
     The present invention has been described by reference to certain preferred embodiments; however, it should be understood that it may be embodied in other specific forms or variations thereof without departing from its essential characteristics. The embodiments described above are therefore considered to be illustrative in all respects and not restrictive, the scope of the invention being indicated by the appended claims.