Abstract:
A surgical apparatus and method according to which an assembly is connected to a handpiece and includes a sensing element and a member adapted to move relative to the sensing element to control the operation of a motor in the handpiece.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to a surgical apparatus including a hand-activated, control assembly, and to a method of using same.  
       BACKGROUND  
       [0002]     Many tools for use in surgical procedures take the form of a handpiece driven by an electric motor to which a cutting accessory, such as a drill bit, bur, saw blade, reamer, and the like, is attached, for removing or separating sections of body tissue.  
         [0003]     A hand-activated control switch is usually provided on the handpiece and a sensing element is provided in the handpiece and cooperates with the switch to generate a signal representative of the position of the switch. The signal is sent to a console that converts the available line voltage into a voltage signal and sends the signal to the motor of the handpiece to power the motor.  
         [0004]     However, these types of arrangements are not without limitations. For example, if the sensing element within the handpiece fails prematurely, then hand-activation of the handpiece is not possible until it is repaired. Also, the switch is designed to work with only those handpieces that have a sensing element in the handpiece, and handpieces that do not have an imbedded sensing element cannot be used with a hand-activated control switch. Moreover, if the sensing element is in the form of a Hall-effect sensing element that detects the proximity of a magnet in or on the lever, the sensing element could be inadvertently activated if the handpiece were placed on or near a magnet or a magnetic surface.  
         [0005]     All patents listed in Table 1 below are hereby incorporated by reference herein in their respective entities. As those of ordinary skill in the art will appreciate readily upon reading the Summary of the Invention, Detailed Description of the Preferred Embodiments and Claims set forth below, many of the devices and methods disclosed in the patents of Table 1 may be modified advantageously by using the teachings of the present invention.  
                               TABLE 1                                   Patent/Publication No.   Patented/Published Date   Inventor                           2002/0087179 A1   Jul. 4, 2002   Culp, et al.                      
 
       SUMMARY  
       [0006]     In order to overcome the above problems, and according to an embodiment of the present invention, a surgical apparatus is provided that includes a sensing element and a switch incorporated in a separate, stand-alone, assembly that connects to a hand piece and to a console. Thus, the assembly can be used with a variety of handpieces, and, if the sensing element fails prematurely, the handpiece is not rendered inoperable, but rather the assembly can simply be replaced with a new one. Also, a Hall-effect sensing element can be used without running the risk of inadvertently activating the sensing element if the handpiece were placed on or near a magnet or a magnetic surface.  
         [0007]     Various embodiments of the invention discussed below may possess one or more of the above features and advantages, or provide one or more solutions to the above problems. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  is an exploded isometric view of an embodiment of the present invention.  
         [0009]      FIG. 2  is an enlarged elevational view of a component of the embodiment of  FIG. 1 .  
         [0010]      FIGS. 3-5  are views similar to that of  FIG. 2  but depicting alternate embodiments of the component of  FIG. 2 .  
     
    
     DETAILED DESCRIPTION  
       [0011]     Referring to  FIG. 1  of the drawings, the reference  10  refers, in general, to a handpiece in the form of a tool for use in surgical procedures. The handpiece  10  is driven by an internal motor  10   a , and is adapted to receive a cutting accessory, such as a drill bit, a bur, a saw blade, a reamer, or the like, that can be removably connected to the output shaft of the motor  10   a . When the motor  10   a  is activated in a manner to be described, the output shaft and therefore the cutting accessory are rotated at a predetermined speed for removing or separating sections of body tissue.  
         [0012]     A sensing element/switch assembly  12  is electrically and mechanically connected to one end of the handpiece  10  for the purpose of activating the handpiece. An electrical cable  14  is electrically and mechanically connected between the assembly  12  and a console  16  that contains electrical circuitry that converts the available line voltage into a drive signal suitable for driving the motor  10   a.    
         [0013]     The assembly  12 , when manually actuated under conditions to be described, produces signals that are transmitted, via the cable assembly  14 , to the console  16  via the cable assembly  14 . The console  16  responds to these signals and, in turn, produces the above drive signals that are transmitted to the motor  10   a , via the cable assembly  14 , so as to cause the motor to operate in a manner to be described.  
         [0014]     The assembly  12  is shown in detail in  FIG. 2  and includes a housing  20  having a male electrical plug, or jack,  20   a  extending from one end thereof that mechanically and electrically engages a corresponding female socket (not shown) provided in the corresponding end of the handpiece  10  ( FIG. 1 ). A female socket  20   b  is formed in the other end of the housing  20  for receiving a corresponding plug, or jack,  14   a  on the corresponding end of the cable assembly  14 . These connections enable signals from the assembly  12  to pass to the console  16  via the cable assembly  14 , and signals from the console  16  to pass to the handpiece  10  through the housing  20  and, since they are conventional, they will not be described in any further detail.  
         [0015]     A lever  22  is pivotally mounted between two spaced mounting flanges extending from the housing  20 , with one of the flanges being referred to by the reference numeral  20   c . It is understood that a biasing member (not shown), such as a leaf spring or the like, can be provided that biases the lever in a direction away from the housing  20  and provides resistance to movement towards the housing, in a conventional manner.  
         [0016]     A Hall-effect sensing element  24  is disposed in the housing  20  with the upper surface of the sensing element extending flush with the upper surface of the housing, as viewed in  FIG. 2 . A magnet  26  is provided in the lever  22  in alignment with the sensing element  24 , with the lower surface of the magnet extending flush with the lower surface of the lever. The sensing element  24  is conventional and, as such, responds to movement of the lever  22 , and therefore the magnet  26 , proximate to the sensing element, and outputs a corresponding signal, as will be described in detail. When the lever  22  is released, the above-mentioned leaf spring forces it back to its original position.  
         [0017]     The cable assembly  14  ( FIG. 1 ) contains a plurality of electrical conductors (not shown) that electrically connect the sensing element  24  to the console  16 , and the console to the motor  10   a , via the housing  20 . Thus, a signal emitted by the sensing element  24  is transmitted to the console  16 , causing a drive signal to be transmitted from the console to the motor  10   a  to drive the motor  10   a . Preferably the latter signal is in the form of a DC voltage that can vary, depending on the position of the magnet relative to the sensing element, to enable the speed of the motor  10   a  to be varied accordingly.  
         [0018]     In operation, the surgeon attaches a cutting tool to the handpiece  10  and when ready, manually pushes, or forces, the lever  22  towards the housing  20  so that the magnet  26  approaches the sensing element  24 . The sensing element  24  is calibrated to output a signal when the magnet  26  gets within a predetermined distance of the sensing element, and the signal is transmitted to the console  16 , via the corresponding conductors in the cable assembly  14 .  
         [0019]     The above-mentioned electrical circuitry in the console  16  responds to the signal received from the assembly  12 , and generates a signal that is passed to the motor  10   a , via the corresponding conductors in the cable assembly  14 . The signal drives the motor  10   a  and enables the speed of the motor to be varied, depending on the position of the magnet relative to the sensing element  24 , as discussed above.  
         [0020]     An alternate embodiment of an assembly is referred to, in general, by the reference numeral  28  in  FIG. 3  and includes a housing  30  having a male electrical plug, or jack,  30   a  extending from one end thereof that mechanically and electrically engages a corresponding female socket (not shown) provided in the corresponding end of the handpiece  10  ( FIG. 1 ). A female socket  30   b  is formed in the other end of the housing  30  for receiving a corresponding plug, or jack (not shown) on the corresponding end of the cable assembly  14 . These connections electrically connect the assembly  12  to the console  16 , and the console to the handpiece  10  through the housing  30  and, since they are conventional, they will not be described in any further detail.  
         [0021]     A lever  32  is pivotally mounted between two spaced mounting flanges extending from the housing  30 , with one of the flanges being referred to by the reference numeral  30   c.    
         [0022]     A strain gauge  34  is disposed in the housing  30  with the upper surface of the strain gauge extending flush with the upper surface of the housing, as viewed in  FIG. 3 . The strain gauge  34  is conventional and, as such, is calibrated to respond to a predetermined force exerted on it and to output a corresponding signal, as will be described in detail.  
         [0023]     A helical compression spring  36  extends between the latter surface and the upper surface of the strain gauge  34  so as to normally urge the lever away from the housing  30 . When the lever  32  is manually pivoted towards the housing  30 , it exerts a force on the spring  36 , which compresses the spring and, in turn, exerts a force on the strain gauge  34 . When the lever  32  is released, the spring forces it back to its original position.  
         [0024]     The cable assembly  14  ( FIG. 1 ) contains electrical conductors (not shown) that electrically connect the strain gauge  34  to the console  16 , and the console to the motor  10   a  in the handpiece  10 , via the housing  30 . Thus, a signal emitted by the strain gauge  34  is transmitted to the console  16 , causing a signal to be transmitted from the console to the motor  10   a  to drive the motor. Preferably, the latter signal is in the form of a DC voltage that can vary, depending on the force exerted on the strain gauge  34 , to enable the speed of the motor  10   a  to be varied accordingly.  
         [0025]     In operation, the surgeon attaches a cutting tool to the handpiece  10  and when ready, manually pushes, or forces, the lever  32  towards the housing  30  against the force of the spring  36  so that a corresponding force is exerted on the strain gauge  34 . The strain gauge  34  is calibrated to output a signal when the latter force reaches a predetermined value, and the signal is transmitted to the console  16 , via the corresponding conductors in the cable assembly  14 .  
         [0026]     The above-mentioned electrical circuitry in the console  16  responds to the signal received from the assembly  12 , and generates a signal that is passed to the motor  10   a , via the corresponding conductors in the cable assembly  14 . The signal drives the motor and enables the speed of the motor to be varied, depending on the force exerted on the strain gauge  34 , as discussed above.  
         [0027]     Another alternate embodiment of an assembly is referred to, in general, by the reference numeral  38  in  FIG. 4  and includes a housing  40  having a male electrical plug, or jack,  40   a  extending from one end thereof that mechanically and electrically engages a corresponding female socket (not shown) provided in the corresponding end of the handpiece  10  ( FIG. 1 ). A female socket  40   b  is formed in the other end of the housing  40  for receiving a corresponding plug, or jack (not shown) on the corresponding end of the cable assembly  14 . These connections electrically connect the assembly  12  to the console  16 , and the console to the handpiece  10  through the housing  40  and, since they are conventional, they will not be described in any further detail.  
         [0028]     A lever  42  is pivotally mounted between two spaced mounting flanges extending from the housing  40 , with one of the flanges being referred to by the reference numeral  40   c . It is understood that a biasing member (not shown), such as a leaf spring or the like, can be provided that biases the lever  42  in a direction away from the housing  40  and provides resistance to movement towards the housing in a conventional manner.  
         [0029]     One portion  44   a  of an inductively coupled circuit is mounted in the lever  42  and another portion  44   b  of the circuit is mounted in the housing  40  and in alignment with the circuit portion  44   a . The circuit portion  44   a  is in the form of a resonant circuit (RLC) and the circuit portion  44   b  includes an inductor. Thus, the circuit portion  44   a  interacts with the circuit portion  44   b  to induce an output signal voltage in the circuit portion  44   b  when the circuit portion  44   a  is within a predetermined distance of the circuit portion  44   b  as a result of the lever  42  being pivoted towards the housing  40 . When the lever  42  is released, the above-mentioned leaf spring forces it back to its original position.  
         [0030]     The cable assembly  14  ( FIG. 1 ) contains electrical conductors (not shown) that electrically connect the circuits  44   a  and  44   b  to the console  16 , and the console to the motor  10   a  in the handpiece  10 , via the housing  40 . Thus, a signal emitted by the assembly  38  in the above manner is transmitted to the console  16 , causing a signal to be transmitted from the console to the handpiece motor  10   a  to drive the motor. Preferably the latter signal is in the form of a DC voltage that can vary, depending on the relative positions of the circuit portions  44   a  and  44   b , to enable the speed of the motor  10   a  to be varied accordingly.  
         [0031]     In operation, the surgeon attaches a cutting tool to the handpiece  10  and manually pushes, or forces, the lever  42  towards the housing  40 . The inductively coupled circuit portions  44   a  and  44   b  are calibrated to output a signal when the lever  42 , and therefore the circuit portion  44   a , gets within a predetermined distance of the circuit portion  44   b  in the housing  40 , and the signal is transmitted to the console  16 , via the corresponding conductors in the cable assembly  14 .  
         [0032]     The above-mentioned electrical circuitry in the console  16  responds to the signal received from the assembly  12 , and generates a signal that is passed to the motor  10   a , via the corresponding conductors in the cable assembly  14 . The signal drives the motor  10  and enables the speed of the motor to be varied, depending on the relative positions of the circuit portions  44   a  and  44   b , as discussed above.  
         [0033]     Another alternate embodiment of an assembly is referred to, in general, by the reference numeral  48  in  FIG. 5  and includes a housing  50  having a male electrical plug, or jack,  50   a  extending from one end thereof that mechanically and electrically engages a corresponding female socket (not shown) provided in the corresponding end of the handpiece  10  ( FIG. 1 ). A female socket  50   b  is formed in the other end of the housing  50  for receiving a corresponding plug, or jack (not shown) on the corresponding end of the cable assembly  14 . These connections electrically connect the assembly  12  to the console  16 , and the console to the handpiece  10  through the housing  50  and, since they are conventional, they will not be described in any further detail.  
         [0034]     A strain gauge  52  is disposed in an opening in the housing  50  with the upper surface of the strain gauge extending slightly below the upper surface of the housing, as viewed in  FIG. 5 . The lower portion of a manually-actuatable button  54  also extends in the latter opening over the strain gauge  52 , with the lower surface of the button in contact with the upper surface of the strain gauge  52 . The upper portion of the button  54  projects outwardly from the upper surface of the housing  50  so that it can be manually engaged, or pressed.  
         [0035]     The strain gauge  52  is conventional and, as such, responds to a force exerted on it by a manual pressing of the button  54  downwardly as viewed in the drawing, and is calibrated to output a corresponding output signal. In this context, it is understood that the button  54  is conventional, and, as such, includes a mechanism to return it to its previous position after being pushed downwardly in the above manner.  
         [0036]     The cable assembly  14  ( FIG. 1 ) contains electrical conductors (not shown) that electrically connect the strain gauge  52  to the console  16 , and the console to the motor  10   a  in the handpiece  10 , via the housing  50 . Thus, a signal emitted by the assembly  48  in the above manner is transmitted to the console  16 , causing a signal to be transmitted from the console to the handpiece motor  10   a  to drive the motor. Preferably the latter signal is in the form of a DC voltage that can vary, depending on the position of the magnet relative to the sensing element, to enable the speed of the motor  10   a  to be varied accordingly.  
         [0037]     In operation, the surgeon attaches a cutting tool to the handpiece  10  and manually pushes the button  54  towards the strain gauge  52  to exert a force on the strain gauge  52 . The strain gauge  52  is calibrated to output a signal when the latter force reaches a predetermined value, and the signal is transmitted to the console  16 , via the corresponding conductors in the cable assembly  14 .  
         [0038]     The above-mentioned electrical circuitry in the console  16  responds to the signal received from the assembly  12 , and generates a drive signal that is passed to the motor  10   a , via the corresponding conductors in the cable assembly  14 . The signal drives the motor  10   a  and enables the speed of the motor to be varied, depending on the amount of force exerted on the strain gauge  52  by the button  54 .  
         [0039]     Since, in each of the above embodiments the sensing element and switch are both incorporated in a single, separate, stand-alone, assembly that connects to the hand piece and to the console, the assembly can be used with a variety of handpieces. Also, if the sensing element fails prematurely, the handpiece is not rendered inoperable, but rather the sensing element\assembly can simply be replaced with a new one. Further, in the embodiment of  FIGS. 1 and 2  there is no risk of inadvertently activating the sensing element if the handpiece were placed on or near a magnet or a magnetic surface.  
       Variations  
       [0040]     It is understood that several variations may be made in the foregoing without departing from the scope of the invention. For example, the sensing element/switch assembly discussed above could be connected directly to the handpiece  10  in manners other than discussed above, such as by mounting or clamping the assembly directly on the handpiece, and electrically connecting the sensing element of the assembly to the console, via the cable assembly  14  described above, or by another cable assembly. Also, the switch in the above embodiments could be replaced by toggle switches, push buttons, or finger/button interfaces. Further, sensing elements other than the ones described above can also be used. Still further, the console can be eliminated if it is not necessary to house the above-described electrical circuit. Moreover, the output shaft of the motor  10   a  can be oscillated, reciprocated, or the like, rather than rotated, as discussed above. Also, the present invention is not limited to surgical instruments employing a cutting element, but may find further applications in which a relatively small instrument is powered from an external console.  
         [0041]     The preceding specific embodiments are illustrative of the practice of the invention. It is to be understood that other expedients known to those skilled in the art or disclosed herein, may be employed without departing from the invention or the scope of the appended claims.  
         [0042]     In the following claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts a nail and a screw are equivalent structures.