Abstract:
A surgical device including a cutting blade; a guard portion movable with respect to the blade from a first position covering the blade to a second position exposing the blade; an actuator shaft; a biasing element; an integrally formed locking element; and a handle having a cavity configured to receive the locking element.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of the earlier filing date of U.S. Provisional Application No. 60/608,100, filed Sep. 9, 2004, entitled “Surgical Actuator and Locking System,” as well as to now pending application Ser. No. 10/092,560, filed Mar. 8, 2002, which is a continuation-in-part of application Ser. No. 09/598,453, filed Jun. 22, 2000, now issued Pat. No. 6,497,687, the disclosure of each of which is incorporated by reference herein. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The device described here is intended specifically for use in surgical systems which require on-off actuators which control function and in turn allow it to occur only once each time a command is given. In addition to that the described system is intended to display the system readiness and the monitoring of its function throughout each cycle. One intended use for this system of locking is its applicability in the control of trocars used in endoscopic surgical procedures such as the one described in U.S. Pat. No. 6,497,687, as well as many other cases where similar results are desired.  
         [0004]     2. Description of the Related Art  
         [0005]     Most existing trocars used for endoscopic surgical procedures are incapable of truly effective prevention of injuries to internal organs during insertion and manipulation of the trocar. Despite intensive efforts to improve present trocar designs, the results are still disappointing. Present procedures frequently injure internal organs, and the resulting wounds are sometimes serious or even fatal. The need for safer trocars is thus imperative, especially given that endoscopic surgical procedures are likely to become more widespread in the future.  
         [0006]     Endoscopic or minimally invasive surgery presents an opportunity to improve present surgical procedures and instrumentation comparable only to the revolutionary effect of the introduction of anesthetics in the 19th Century.  
         [0007]     Most present day trocars utilize a tip shield, or cover, for the cutting edges which is usually deployed immediately after penetration of the body cavity has taken place. Such penetration is fraught with danger of injury to internal organs. However careful a surgeon may be during penetration of the body cavity, the resistance to penetration drops at the last instant prior to damage to the internal organs. This sudden drop in the resistance to penetration is called a “plunge effect” and occurs prior to any safety feature deployment. In some trocars, the penetration is controlled in some fashion, either taking place in small increments or under some form of approximate direct observation, estimate, or monitoring. In all cases, however, the designs result in much of the piercing tip being inserted to a dangerous depth before any protecting devices is deployed. This is perhaps not surprising since, after all, a hole must be made before any protection is deployed.  
         [0008]     Since in most cases delicate organs are very close to the inside of the skin layer being pierced, it is advisable to perform the penetration after internal cavities have been filled with carbon dioxide to minimize the danger of accidental injury due to contact with the sharp piercing tip or the cutting edges of the instrument. In most cases, however, the force required for penetration and the elastic nature of the muscular layer cause a severe depression at the surgical portal, therefore bringing the penetrating tip of the instrument closer to the internal organs. In some of those cases, the sudden penetration of the cavity wall and the rapid drop in resistance allow the instrument to be propelled far deeper than desired or possible to control. Furthermore, friction between the tissue walls and any protective device retards the deployment of the protective device, and an injury almost inevitably occurs.  
         [0009]     Accordingly, a safer surgical device for use in endoscopic procedures is desired.  
       SUMMARY OF THE INVENTION  
       [0010]     One aspect of the present invention includes a surgical device including a cutting blade; a guard portion movable with respect to the blade from a first position covering the blade to a second position exposing the blade; an actuator shaft extending along an axis of the surgical device from a first end connected to the guard portion to a second end; a biasing element; an integrally formed locking element; and a handle having a cavity configured to receive the locking element.  
         [0011]     Another aspect of the present invention includes a method of using a surgical device including depressing an actuating portion to remove a guide portion of a locking element from a locking notch; moving the locking element from a first position to a second position to uncover a penetrator protected by a guard portion connected to the locking element; piercing a membrane such as the peritoneum of a patient with the penetrator; and moving the locking element from the second position to the first position to recover the penetrator with the guard portion.  
         [0012]     A further aspect of the present invention includes a method of assembling a surgical device including attaching an integrally formed locking element to an actuator shaft; inserting a biasing element into a hub of the locking element; placing the locking element in a first handle portion with one end of the biasing element facing a surface of the first handle portion; and connecting a second mating handle portion to the first handle portion over the locking element. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:  
         [0014]      FIG. 1  is a top plan view of a preferred embodiment of the present invention;  
         [0015]      FIG. 2  is a side elevational view thereof;  
         [0016]      FIG. 3  is a proximal end view thereof;  
         [0017]      FIG. 4  is a perspective view of an integrated actuator button and latch module of an embodiment of the present invention;  
         [0018]      FIG. 5  is a side cross-sectional view of the present invention;  
         [0019]      FIG. 6  is a proximal end cross-sectional view taken along line  6 - 6  of  FIG. 5 ;  
         [0020]      FIG. 7  is a side cross-sectional view of the present invention in a rest position;  
         [0021]      FIG. 8  is an end cross-sectional view taken along line  8 - 8  of  FIG. 7 ;  
         [0022]      FIG. 9  is a side cross-sectional view of the present invention in an arming position;  
         [0023]      FIG. 10  is an end cross-sectional view taken along line  10 - 10  of  FIG. 9 ;  
         [0024]      FIG. 11  is a side cross-sectional view of the hold downs in the arming position;  
         [0025]      FIG. 12  is a side cross-sectional view of the present invention in a release position;  
         [0026]      FIG. 13  is an end cross-sectional view taken along line  13 - 13  of  FIG. 12 ; 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0027]     Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views.  
         [0028]     Referring to the drawings enclosed here,  FIG. 1  is a top plan view,  FIG. 2  is a side view, and  FIG. 3  is a proximal end view of the outside of a trocar  1  according to a preferred embodiment of the present invention.  FIGS. 1-3  offer a context for the details of the locking system inside the handle.  FIGS. 1-3  show a trocar  1  having a distal end  2  and a proximal end  3  and is provided with a blade  6  housed within safety guard tips  13 ,  14 . While the preferred embodiment utilizes a metal blade, it is understood that any sharpened, substantially flat member made of another material such as plastic or a composite material could be utilized. The main element of the mechanism is shown in  FIG. 4  which is called the integrated actuator button and latch module  23 .  FIG. 5  shows the inside of the proximal end of the handle without some of the internal mechanisms to facilitate initial understanding of the context space.  FIG. 6  shows a cross-section taken along line  6 - 6  of  FIG. 5  looking toward the left as indicated by the arrows. The flexible hold-downs  17 ,  17  are shown attached to the housing at their bottom end.  
         [0029]      FIG. 7  shows the complete mechanism within the inside of the handle described above. The system is shown here in its initial, or rest, position prior to actuation.  FIG. 8  shows the inside of the mechanism as seen in the direction of section arrows  8 - 8  in  FIG. 7 .  FIG. 9  shows the internal configuration of the mechanism right after the actuation set up, or arming. The actuator button  23  as shown has been pushed down and it is now free to move. The actuator latch is now out of engagement with a locking notch  16 ′ and is free to move to the right as shown in  FIG. 9 .  FIG. 10  shows the cross-section taken along line  10 - 10  in  FIG. 9 .  FIG. 11  shows an enlarged detail of the ridge of a hold-down  17 ,  17  while holding the latch in the free-to-move position detached from its locking notch  16 .  
         [0030]      FIG. 12  shows the entire actuator button and locking system  23  sliding toward the right after snapping off and shifting upwards from the hold-downs  17 ,  17  and against the bottom sides of its guide groove  16 ″. In that position the actuator button and latch module  23  is able to return under the action of a spring  31  toward the left and lock back into its locking notch  16 , thereby relocking the whole mechanism at its initial position, as shown in  FIG. 7 .  
         [0031]     As shown in  FIGS. 1, 2 , and  3 , element  4  is the top of the cannula handle containing the luer  7  and attached to cannula  15 . Element  12  comprises the tip expander of a penetrator tube  10 . Safety guard tips  13  and  14  are provided as shown. Inside of the cannula  15  are the penetrator tube  10  and the actuator or obturator shaft  11 . Another important element is the actuator button  23  fitted into the groove on the top portion  5  of the proximal housing/handle. The bottom parts  8 ,  9  of the handle are on the distal end side and on the handle proximal end.  
         [0032]     In  FIG. 4  is shown the important elements that integrate the actuator button  23  and the latches  30 . The button  23  is connected through spring portions  25  and  26  to the hub  27  that is attached to the actuator shaft  11 , and to the spring housing  28  and spring guide bore  29 .  
         [0033]      FIG. 5  shows the horns  6  of the trocar and the elements of the penetrator handle housing portion  5  and part  9  which together form the housing for the whole actuator module  23 . The housing portion  5  of the proximal handle also forms a support for the penetrator tube  10 . The housing bottom engages the top portion  5  forming a substantially spherical proximal end well fitted for being grasped by a surgeon&#39;s hand. The proper engagement between the top portion  5  and the bottom  9  of the handle housing is insured by a pin  22  which protrudes from a downwardly extending stud  18  which protrudes from the top portion  5  and fits into a hole  19  in a second stud  21  at the interim portion  20  of the bottom member  9 . That insures precise alignment between the two halves of the handle end. The bottom member  9  also holds the two hold-downs  17 ,  17  protruding into the top space inside  5 , and having protruding rims  17 ′,  17 ′ that in turn engage the surfaces  30 ′ of the latches  30 ,  30  at the sides of the actuator button  23  shown in  FIG. 4  (not shown here). The hold-downs having protruding rims  17 ′,  17  at their tops also have those rims  17 ′,  17 ′ which are beveled with bevels  17 ″,  17 ″, respectively, toward the inside to avoid interference with the passing back and forth of the moving button latches when they are not being held down.  
         [0034]     At the top of handle housing  5  on  FIG. 4  there is a guide space formed between walls  16 ,  16  to guide the actuator button  23 . The guide between the walls  16 ,  16  has a lower edge thereof notched as shown by notch  16 ′ to serve as a locking notch for the actuator latches  30 ,  30  which spring into them to lock the system and prevent motion of the actuator system. That is the purpose for the locking notch  16 ′ being provided.  
         [0035]      FIG. 6  shows the inside of the handle in section as seen from the right in the direction of the arrows in line  6 - 6  appearing in  FIG. 5 . The walls  16  at the sides of the guide have the notch  16 ′ as shown in  FIG. 6  to provide the spaces for the locking latches  30 ,  30  of the actuator button to lock into them at the start or end of each work cycle. As seen in  FIG. 6  the tops of the hold-downs  17 ′ are tilted some 45° toward the inside to match the slope  30 ′ of the latches  30 ,  30  that will engage them and spread them apart when the button  23  is depressed, and the locking is effected when the hold downs rims  17 ′,  17 ′ snap over them. Such action will be discussed in greater detail hereinbelow.  
         [0036]      FIG. 7  shows the full actuator mechanism assembled and in the locked position. The actuator shaft  11  is shown inserted into the hub  27  and a small shear pin  27 ′ is inserted across the hub to fix it in place. A coil spring  31  is inserted into the bore  29  at the right end of the spring housing cylinder  28 . The squared end of the spring  31  is inserted into a seat  32  at the junction between the two handle halves  5  and  9 . The left end of the actuator including spring portion  26  will contact the frontal inside wall of the top portion  5  of the housing and prevent any further leftward movement. The spring portion  25  of the actuator button module will be slightly depressed forcing the actuator button  23  upward and the latches  30 ,  30  into their locking notches  16  such that no axial motion will be possible.  
         [0037]      FIG. 8  shows the inside of the system as seen from the right side across the section plane  8 - 8  of  FIG. 7 . In this figure the button  23  is shown fully protruding above its guide plane. The serrated edge  24  is highly visible. The top of the latch arms  30 ′,  30 ′ are fully inserted into the locking notches  16 ′ and the system is locked onto the guide at each side. At this time there is no contact between the actuator button and locking module shown in  FIG. 4  and the two hold-down arms  17 ,  17 ′. This is the normal locked position of the system prior to arming it.  
         [0038]      FIG. 9  shows what happens when the actuator button  23  is pushed down into the housing. The spring portion  25  of the module bends downward and the locking latch surfaces  30 ′,  30 ′ are forced down against the top of the hold-down top ring  17 ′ tilted 45° inwardly, and the module 45° angle latches  30 ″,  30 ″ slide against them forcing them to open as shown in  FIGS. 10 and 11  until the tips of the latches  30  pass down and the ridges  17 ′,  17 ′ snap and click inwardly over surface  30 ′ catching it as shown in  FIG. 11  and holding it away from the locking notch  16 ′. In that position the system is said to be armed since it can be axially moved by any force applied inwardly against the tip of the safety guards, as when starting a penetration.  
         [0039]      FIG. 12  shows what happens when an inward force is applied to the tip of the safety guards. Since in the armed position there is no structure to stop the motion (there is no locking latch inserted into a notch  16 ′ because the latches are being held down away from the lower edge of the guides  16 ), the whole actuator button  23 , along with the entire sensing system of safety guards and actuator shaft  11  moves to the right until the latches lose contact with the hold-down ridges  17 ′,  17 ′ and snap out and against the lower edge of the guides  16 ″,  16 ″ but far to the right of the locking notch  16 ′, so the module is free to either move right, or return to the left.  
         [0040]     In the position shown in  FIG. 13 , the module latches  30 ′,  30 ′ slide freely against the lower edge of the guides  16 ″,  16 ″ while still touching the slanted tops of arms  17 ,  17  with a slight contact against them, but easily sliding. The hold-down arms  17 ,  17  shown in  FIG. 13  do not close down completely but keep slightly in touch with the latches  30 ,  30  until the latches return and reach the locking notch  16 ′ and snap to lock again at the end of each cycle. To minimize the extent of the initial deflection of the spring  25  which might have to deflect too much from a large gap between latches and hold-downs at the start, the frontal bevels  33  shown facilitate the sliding between the latches  30 ,  30  and the top of the hold-down ridges  17 ′,  17 ′ while upon return to the locking direction. It has been found that the system described here represents the best mode of operation since at no time is there any slack between parts which might induce a malfunction. All parts are in sliding contact throughout critical functions.  
         [0041]      FIG. 5  shows another optimization of arms  17 ,  17  wherein is shown a slight bevel  17 ″ at the right edge of ridge  17 ′. The presence of bevel  17 ″ will facilitate easy entrance of the bevel  33  at the distal edge of the latches  30  on the return trip. Those two latches  30  could also have conical surfaces at the front and bottom instead of the pyramidal structure shown. The choices depend on the materials chosen and their coefficients of friction, and that is more a question of manufacturing preference than inventive requirement. It is also entirely possible to design this system for avoiding contact between the returning latches and the hold-downs, and by so doing also avoid need for the frontal ring  17 ″ and bevel  33 . However, in the interest of good engineering practice the configuration described represents the best mode and that is why it is preferred.  
         [0042]     Basically, the actuation system described here represents an important set of ideals. In the first place, it is the simplest approach to the design of locking systems for disposable medical devices which could be easily reset if so desired. This system is characterized by an integration of functions that are usually far more complicated. The most important element of this system is the actuator button with locking latches, integral spring, locator for driving shaft, housing for external spring, and functional indicator with visual, tactile and acoustic clues. Altogether eight functions in one single element. The rest of this system require simple modifications of parts that already exist in all similar instrument housings, which means that with the insertion of a single new part all the rest of the required functions are obtained. This may sound like an exorbitant claim but it is a physical fact easily verifiable and is hardly contestable.  
         [0043]     Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.