Abstract:
Devices and methods are described to rapidly and easily install a control device in a resecting tool system. The motor portion of the resecting tool can be readily separated from the air conduit to which it is attached. In a preferred embodiment, modular hand-operated control is then inserted between the air conduit and motor and interconnected with both components. The modular hand-control provides a housing with an actuatable lever, or handle, which controls an internal valve assembly.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to surgical instruments used for the resectioning of bone or other tissue. In other aspects, the present invention relates to methods and devices for actuating such surgical instruments. In one particular aspect, the present invention relates to a modular hand-control for use with a pneumatic resecting tool. 
     2. Description of the Related Art 
     Surgical instruments employing fluid-powered motors to rotate cutting or resectioning tools are conventional and well-known in the art. Such surgical tools are used in such delicate surgical operations as brain surgery and microsurgery. These surgical instruments must be capable of sanitary operation without contaminating an operating room environment. Also, because of the delicate nature of surgery, the surgical instrument must be manipulated easily by the surgeon without causing undue fatigue, which could lead to disastrous surgical errors. 
     Pneumatic resecting tools of this type are disclosed, for example, in U.S. Pat. Nos. 5,549,634; 5,352,234; 5,505,737; 5,569,256; 5,439,005; and 5,741,263. Traditionally, these tools are part of a tool system in which the tool is actuated using a foot pump or foot valve which a surgeon operates with his foot. The foot pump is typically located proximate the air pump that provides fluid pressure to operate the tool. 
     There are a number of surgical instrument systems that incorporate hand-operated controls for the instrument. Examples of such systems are discussed in U.S. Pat. Nos. 3,712,386; 3,752,241; 4,530,357; 5,478,093 and Re. 27,032. However, these systems do not permit the hand control to be disconnected from the surgical instrument. Thus, the hand-operated control cannot be removed from the system when it is desired not to use it. 
     Quick release couplings are also known for use with surgical instruments such as this. Examples of these type of release couplings are found in U.S. Pat. Nos. 5,505,737; 5,569,256 and 5,741,263. However, these devices are intended for releasably securing a cutting tool to the spindle shaft of a drive motor. In other words, they are useful for interconnecting the working end of the tool with the motor, thus providing a means of, for example, quickly changing out the tools during operation. They are not, however, designed to provide an interconnection between the motor section and the air conduit for the instrument. Nor do they provide any means for operably associating a hand-operated control with the tool. 
     Some surgeons may, however, prefer to use a hand-operated control rather than a foot-operated control. Where it is desired to begin using foot control, rather than hand control, there is an advantage to removing, or disabling, the hand control, to prevent inadvertent operation or interruptions in operation, of the surgical tool. 
     Therefore, a need exists for devices and methods that permit the quick and easy interconnection of a hand-control for resecting tools and similar devices. 
     SUMMARY OF INVENTION 
     The present invention provides methods and apparatus for a modular device control to be rapidly and easily installed in a resecting tool system. The motor portion of the resecting tool can be readily separated from the air conduit to which it is attached. In a preferred embodiment, modular hand-operated control is then inserted between the air conduit and motor and interconnected with both components. The modular hand-control provides a housing with an actuatable lever, or handle, which controls an internal valve assembly. Preferably, the hand control can be operably associated with the tool system by using quick releases. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic view of a prior art resecting tool system showing a resecting tool having a motor interconnected with the air conduit. 
     FIG. 2 depicts a preferred embodiment of a surgical instrument system of the present invention wherein a modular hand-control has been installed between the air conduit and motor component. 
     FIG. 3 is an exploded view, partially in cross-section, showing portions of the system depicted in FIG. 2 in which one embodiment of a modular hand-control is employed. 
     FIG. 4 is cross-sectional view of the hand control shown in FIG. 3 wherein the control has been actuated to permit fluid flow through the control. 
     FIG. 5 is a cross-sectional view of an alternative embodiment of a modular hand control constructed in accordance with the present invention. 
     FIG. 6 provides an exploded view of the hand control shown in FIG.  4 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring first to FIG. 1, an exemplary prior art surgical tool system  10  is shown schematically. The system  10  includes an air pump or fluid pump  12  associated with an air or fluid conduit  14  to provide pressurized air to a surgical instrument or tool  16 , which is shown in enlarged detail in FIGS. 1 and 2. It is noted that the air conduit  14  is coaxial having an inner conduit, or liner, that defines a passageway that provides pressurized fluid from the pump  12  to the surgical instrument  16  and an outer conduit, or liner that returns fluid from the instrument  16  to the pump  12 . 
     The surgical instrument  16  includes a motor  18  that is affixed to the air conduit  14  by means of threading or pinning (not shown). A base  20  is affixed to the motor  18  by a threaded connection (not shown) as well. A support sleeve  22  extends from and is joined at an end  24  of the base  20 . The support sleeve  22  houses the tool shaft  26  of a resecting tool  28 . At one end of the resecting tool  28  is a cutting element  30 . The cutting element  30  can be a burr, saw blade or drill used in the cutting or removal of tissue. The sleeve  22  may be provided with internal bearings (not shown) to support the tool shaft  26  as the resecting tool  28  is rotated. 
     Mounted around the base  20  is a sleeve engagement collar  32 . The sleeve engagement collar  32  is longitudinally moveable relative to the base  20  and is provided with an annular, lower facing shoulder (not shown). Positioned below the collar  32  is a cylindrical spring housing  34  that surrounds and is joined at its lower end to the base  20 . The wall of the spring housing  34  is spaced apart from the exterior of the base  20  to define and annular space (not shown) for receiving the lower end of an outer coiled spring (also not shown) which surrounds the base  20 . The collar  32  has a lower cylindrical portion or skirt (not shown) which surrounds the upper end of the coiled spring and is received within the spring housing  34 . The skirt of the collar  32  is able to slide within the spring housing  34  for a distance as the collar  32  is moved in relation to the base  20 . It is noted that the collar  32  and spring housing  34 , as well as the coiled spring and associated components, are part of a release arrangement that permits rapid changing out of the resecting tool  28  during operation of the surgical instrument  16 . This type of tool-changing release arrangement, as well as further details concerning operation of the exemplary surgical instrument  16  is described in greater detail in U.S. Pat. No. 5,505,737 issued to Gosselin et al. This arrangement is mentioned here merely for the sake of completeness. It is noted that the use of this or any release arrangement for the removal or replacement of the resecting tool  28  from the motor portion  18  of the surgical instrument  16  is not necessary to the invention and is merely described as background for the present invention. 
     A foot-operated control valve  36  is shown incorporated into the conduit  14  so that a surgeon or other individual can actuate the tool  16  by depressing the valve  36 . The valve  36  is securely, and perhaps permanently, associated with the conduit  14  so that it cannot be readily removed. 
     Referring now to FIG. 2, a preferred embodiment of an improved resecting tool system  100  is shown. For simplicity and clarity, like components between the two described surgical tool systems are numbered alike. Although not shown in FIG. 2, a foot-operated control, such as the control  36  shown in FIG. 1, may or may not be present along conduit  14 . 
     A first exemplary embodiment of a modular hand control  102  is shown between the motor assembly  18  and the conduit  14 . The conduit  14 , as illustrated by FIG. 3, has an inner liner  15  that defines an inner passage  17  through which pressurized fluid is transmitted from the pump  12  toward the instrument  16 . The inner liner  15  is surrounded by an outer liner  19  that defines an outer passage  21  through which fluid can be communicated back to the pump  12 . 
     The hand control  102  is shown in greater detail in FIGS. 3 and 4 and can be seen to have a central cylindrical housing  104  with a central fluid flowbore  106  defined therein and disposed longitudinally therethrough. A second, peripheral fluid flowbore  107  is also disposed longitudinally through the housing  104 , but is not centrally located within the housing. It should be understood that there may be more than one such peripheral fluid flowbore  107 , or the peripheral flowbore  107  may be semicircular in shape so that the flowbore  107  is not blocked by elements of the valve, including piston  134  which will be described. 
     A receptacle  108  is formed in a first end of the housing  104  and contains a groove  110  milled upon its internal wall. The groove  112  is L-shaped so that a longitudinal portion  112  and a lateral portion  114  are provided. The receptacle  108  is shaped and sized to receive the complementary-shaped pin connector  116  that extends from the motor assembly  18 . A lug  118  extends radially from the pin connector  116 . The lug  118  is shaped and sized so as to be slidably received within the groove  112  of the receptacle  108 . 
     A cylindrical fitting  120  is securely affixed to the conduit  14  and contains a receptacle  122  and milled L-shaped groove  124  which are formed in the same manner as the receptacle  108  and groove  110  described earlier. It is preferred that the receptacle  122  and groove  124  have essentially the same dimensions and size as the receptacle  108  and groove  110 , as well. 
     A pin connector  126  is formed in the longitudinal end of the housing  104  opposite the receptacle  108  of the hand control  102 . A lug  128  extends radially from the pin connector  126 . The lug  128  is shaped and sized to be slidably received within the groove  124  of the receptacle  122 . Again, it is preferred that the pin connector  126  and lug  128  be essentially the same size and shape as the pin connector  116  and lug  118 , respectively. The similar sizing of the pin connectors and receptacles, as well as the grooves and lugs, permits the motor assembly  18  of the tool  16  to be affixed either to the modular hand control  102  or else directly to the fitting  120  of the air conduit  14 . Additionally, the fitting  120  can be affixed either to the hand control  102  or directly to the motor assembly  18 . 
     It is also noted that elastomeric O-rings  129  may be present on the pin connectors  116 ,  126  in order to help create fluid sealing of the components. 
     A valve assembly, shown generally at  130 , is operable to control the flow of air or other fluid from the pump  12  to the tool  16 . The valve assembly  130  includes a piston passageway  132  that is disposed through the housing  104 . A piston  134  is reciprocably disposed within the passageway  132  so that it can selectively block the flow of fluid through the flowbore  106 . A lever  136  is pivotally connected to the housing  104  at a pivot point  138 . A linkage  140  interconnects the lever  136  to the piston  134  so that the piston  134  is moved within the passageway  132  as the lever  136  is pivoted about the pivot point  138 . It is preferred that there be a spring (not shown), such as a torsional spring, that biases the lever  136  into a position away from the housing  136  so that the piston  134  is located so as to block the flow of air through the flowbore  106  toward the tool  16 . When the lever  136  is pushed downwardly (preferably by hand), toward the housing  104 , the piston  134  is moved within the passageway  132  so that fluid flow through the flowbore  106  is no longer blocked and the motor  18  of the tool  16  will function to operate the tool  16  as shown in FIG.  4 . Thus, the tool  16  can be selectively operated by operating the valve assembly  130  of the hand control  102 . 
     During operation, the modular hand control  102  may be rapidly installed or removed from the tool system  100 . To install the hand control  102 , the motor section  18  of the tool  16  is affixed to the hand control  102  by disposing the pin connector  116  within the receptacle  108 . The lug  118  is slidingly disposed into the longitudinal portion  112  of the groove  110 . The motor section  18  can be securely locked to the hand control  102  by rotating the motor section  18  with respect to the hand control  102  so that the lug  118  becomes disposed within the lateral portion  114  of the groove  110 . Next, the pin connector  116  is affixed in a locking relation to the fitting  120  of the air conduit  14  in a similar manner. When the hand control  102  is affixed in this manner, the central longitudinal passageway  106  of the housing  104  is aligned with and adjoins inner passage defined by the inner liner  15  of the conduit  14 . The longitudinal passageway  107  of the housing  104  is aligned with and adjoined with the outer passage  21  defines by the outer liner  19  of the conduit  14 . As a result, pressurized fluid from the pump  12  is directed from the inner passage  17  into the central passageway  106  of the housing  104  and, then to the instrument  16 . Fluid returning from the instrument  16  toward the pump  12  is directed through the longitudinal passageway  107  in the housing  104  and then into the outer passage  21  whereby it can return to the pump  12 . 
     The modular hand control  102  may be readily removed from the tool system  100 . This can be done if it is desired to control operation of the tool  16  by some other means, such as by a foot valve (not shown). In order to remove the control  102  from the system  100 , the control  102  is rotated with respect to the fitting  120  and the motor assembly  18  so that the lugs  118 ,  128  are released from the lateral portions of the grooves  110 ,  124 . The connections provided between these components are quick release connections since they do not require time-consuming operations such as the unthreading of threaded connections or the removal of separate pins. 
     Referring now to FIGS. 5 and 6, an alternate exemplary embodiment is depicted for a hand control  200  constructed in accordance with the present invention. This hand control  200  shares many of the same features provided by the hand control  102  described earlier, but also incorporates a check valve assembly designed to prevent unwanted release of fluid pressure when the components of the system are disconnected. The hand control  200  also includes an outer fluid flow passageway for fluid so that the control can be used with coaxial fluid pressure conduits that provide a return passageway whereby fluid is returned from the tool to the air pump  12 . 
     The hand control  200  includes an outer housing  202  that is formed from first and second housing sections  204 ,  206 . The first housing section  204  fits within and is threadedly affixed to the second housing section  206  by threaded connection  208 . An elastomeric O-ring  210  is secured within the threaded connection  208  to assist in creating a fluid seal. The first housing section  204  features a reduced diameter portion  212  and an expanded diameter portion  214 . The reduced diameter portion  212  provides an inwardly-directed annular flange  216  (visible in FIG. 4) with a fluid communication port  218  disposed therethrough. The expanded diameter portion  214  includes a receptacle  219  and a groove  220  which is cut into the material forming the expanded diameter portion  214 . As with the grooves  110 ,  124  described earlier, the groove  220  provides a lateral portion  222  within which a suitably sized and shaped lug can reside. 
     The second housing section  206  includes a receptacle  224  within which the reduced portion  212  of the first housing resides. A coaxial pin connector  226  is provided at the opposite end of the second housing section  206  and is adapted to have a coaxial air conduit  228  (shown in FIG. 5) slipped on to it to form a connection. A lug  227  (visible in FIG. 6) extends radially outwardly from the connector  226 . 
     As is apparent from FIG. 4, the coaxial conduit  228  is made up of an outer conduit member  230  that defines an outer airflow passage  232  and a coaxially-located inner conduit member  234  that defines an inner airflow passage  236  therein. 
     A valve body  240  is retained within the receptacle  224  between the first and second housing section  204 ,  206  when they are assembled. The valve body  240  defines a longitudinal fluid flowbore  242  and a vertical valve chamber  244 . Fluid apertures  246  are provided around the periphery of the valve body  240  so that fluid within the receptacle  224  can be communicated across the valve body  240  and into the pin connector  226 . 
     A valve stem  248  is secured to the valve body  240  by threading or another secure means of affixation. The valve stem  248  includes both an axial fluid opening  250  and radial fluid openings  252 . 
     The valve chamber  244  houses a valve spindle  254  that contains a lateral fluid port  256 . O-rings  258  ensure fluid sealing between the spindle  254  and the chamber  244 . An actuator pin  260  is secured by threaded connection to the valve spindle  254 . The actuator pin  260  includes an elongated shaft  262  and an enlarged head  264 . A spring  266  surrounds the shaft  262  to bias the valve spindle  254  to a lower position within the valve chamber  244 . When so biased, the spindle  254  blocks fluid passage through the passageway  242 . 
     An actuator lever  268  is secured by pintle  270  and pin  272  to the first housing section  204 . The actuator lever  268  has a proximal end  274  adapted to be engaged by a hand and a distal end  276  for operation of the actuator pin  260 . The actuator pin  260  passes through lo the distal end  276  of the lever  268  so that the distal end  276  is disposed beneath the enlarged head  264  of the actuator pin  260  such that when the lever  268  is pivoted about the pivot pin  272 , the actuator pin  260  and valve spindle  254  are moved upwardly within the valve chamber  244  so that the fluid port  256  becomes aligned with the fluid passageway  246 , thereby permitting fluid to be communicated across the valve body  240 . 
     A check valve assembly  274  is incorporated into the hand control  200  so that unwanted fluid escape from the inner airflow passage  236  does not occur when the components are disconnected from one another. The check valve assembly  274  includes a check ball  276  that is biased by spring  278  against a valve seat  280 . The valve seat  280  is affixed to the valve body  240  to retain the spring  278  and check ball  276  within a check valve chamber  282 . The valve seat  280  presents a nipple-type fitting  284  adapted to engage a portion of the motor  18  of instrument  16  by a complimentary interference fit. An O-ring  286  assists in fluid sealing. 
     In operation, the check ball  276  is normally biased by the spring  278  and by fluid pressure against the valve seat  280 . Therefore, fluid is blocked from exiting the valve seat  280  by the check ball  276 . However, when the nipple-type fitting  284  of the valve seat  280  is engaged with the motor  18 , a central protruding portion of the motor  18  will contact the check ball  276  to push it off of the valve seat  280 , thus permitting fluid to pass through the check valve assembly  274 . As a result of the check valve assembly  274 , pressurized fluid can only escape the hand control  200  when the hand control  200  is affixed to the motor  18 . 
     The coaxial pin connector  226  is made up of the outer sleeve  238  of the second housing section  206  and the valve stem  248  which is retained therein. The pin connector  226  is adapted to interconnect with the air conduit  14  of the system so that the valve stem  248  engages the inner liner  234  of the coaxial conduit  228  and the outer sleeve  238  engages the outer liner  230  of the coaxial conduit  228 , thus permitting coaxial air flow between the two components. 
     Other embodiments could include distal or proximal swivels in the modular hand control assembly or in the adjacent assembly to prevent binding or kinking. While the invention has been shown in only one of its forms, it should be apparent to those skilled in the art that it is not so limited, but it is susceptible to various changes without departing from the scope of the invention.