Patent Publication Number: US-2006020258-A1

Title: Surgical apparatus with a manually actuatable assembly and a method of operating same

Description:
CROSS-REFERENCE  
      This application claims priority of provisional application Ser. No. 60/589,399, filed Jul. 20, 2004. 
    
    
     FIELD OF THE INVENTION  
      This invention relates to a surgical tool assembly utilizing a manually-controlled switch assembly, and a method of operating same.  
     BACKGROUND  
      Many surgical tool assemblies include a motorized handpiece to which a cutting accessory, such as a drill bit, bur, saw blade, reamer, or the like, is attached, for removing or separating sections of body tissue. The handpiece is often connected to a separate switch for activating the handpiece, and to a separate, stand-alone, console. The console is connected to a source of AC power and contains electronics that converts the AC line voltage to a voltage suitable for driving and controlling the operation of the handpiece.  
      However, the console is bulky, somewhat complicated to set up, and is not very mobile. Also, at least two electric cables must be connected between the console and the switch, and between the console and the handpiece, respectively.  
      Other arrangements of the above type do not use a console but rather mount the above electronics in the handpiece. However, the handpiece must be autoclaved before each use to sterilize it, which can have a deleterious effect on the electronics.  
      All patents and patent applications listed in Table 1 are hereby incorporated by reference herein in their respective entireties. 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               Serial No.   Date/Filed   Inventor                          2004/0155132 A1   August 12, 2004   McPherson et al.           10/699,474   October 31, 2003   Farrow et al.                      
 
     SUMMARY  
      The above problems are solved by an embodiment of the present invention, in which the console is eliminated and a manually-actuatable switch assembly is provided that contains a portable source of electrical energy, and is adapted to control the operation of the motor. This assembly is relatively small, utilizes only one cable, is relatively easy to set up and is more mobile for office-based procedures, as well as procedures in remote settings. Also, the assembly does not have to be sterilized.  
      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  
       FIG. 1  is a partial elevational/partial diagrammatic view of an embodiment of the present invention.  
       FIG. 2  is a plan view of a component of the embodiment of  FIG. 1 .  
       FIG. 3  is a diagrammatic view of the electrical connections between the components of  FIG. 1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Referring to  FIGS. 1 and 2  of the drawings, the reference  10  refers, in general, to a handpiece in the form of an electrically powered tool for use in surgical procedures, such as the removal or separation of body tissue. The handpiece  10  is driven by an internal electrical motor  10   a , and is adapted to receive a cutting accessory (not shown), 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  in a conventional manner. When the motor  10   a  is activated in a manner to be described, the output shaft, and therefore the cutting accessory, are rotated, reciprocated, and/or oscillated at a predetermined speed to enable the surgical procedure to be performed.  
      A switch and control assembly  12  is provided for activating the motor  10   a  and controlling the operation of the handpiece  10  in a manner to be described. An electrical cable assembly  14  is electrically and mechanically connected between the assembly  12  and the handpiece  10 , and includes a plurality of insulated electrical conductors that function in a manner to be described.  
      As shown in  FIGS. 1 and 2 , the assembly  12  includes a housing, or base member,  16  located a distance from the handpiece. A pedal  18  is pivotally mounted to the base member  16  in a manner so that at least a portion of the pedal is elevated relative to the base member. The pedal  18  is shown in its normal, non-pressed position but can be manually pressed downwardly towards the base member  16 , by the foot or hand of the operator. After being pushed downwardly and released, the pedal  18  will return to its raised, or inactive, position by a spring, or other biasing device (not shown).  
      A switch  18   a  is mounted in the base member  16 , is electrically connected in an electrical circuit  20  provided in the base member, and responds to movement of the pedal  18  for changing an electrical characteristic of the circuit in a manner to be described.  
      A portable source of electrical energy, such as DC power,  22  is also contained in the base member  16  and is connected in the electrical circuit  20 . Preferably, the source  22  is a reusable or rechargeable energy source which could be in the form of a rechargeable battery, such as a lithium ion or nickel cadmium battery. To this end, it is understood that the base member  16  can include a jack, or terminal, (not shown) for receiving a cable leading from a electrical charger (not shown) which can be a dedicated charger or a charger from another surgical device, for charging the source  22 .  
      One or more of the electrical conductors in the cable assembly  14  are connected between the electrical circuit  20  and the motor  10   a  of the handpiece  10  to establish a path for the flow of electrical energy from the source  22  to the motor. The design is such that when the pedal  18  is in its normal, raised position shown in  FIG. 1 , the switch  18   a , and therefore the electrical circuit  20 , are open; and when the pedal  18  is manually pressed downwardly towards the base member  16  by the operator, the switch  18   a  and the electrical circuit  20  are closed. In this closed condition of the electrical circuit, electrical energy from the source  22  flows through the electrical circuit  20  and to the motor  10   a  to power, or energize the motor. It is understood that the switch  18   a  and the electrical circuitry  20  associated with the pedal  18  can allow the speed of the motor  10   a  to be varied within its selected range by varying the degree of pressing of the pedal, in a conventional manner.  
      A series of four push-button/switch assemblies  26   a,    26   b,    26   c,  and  26   d  are provided on the base member  16  and are connected to the electrical circuit  20  to control various operational modes of the motor  10   a , including changes in direction of movement, speed, speed ranges, and the like. The push button of each assembly  26   a - 26   d  can be manually pressed downwardly towards the base member  16  by the foot of the operator, and, after being released, will return to its raised, or inactive, position by a spring, or other biasing device (not shown). Each assembly  26   a - 26   d  includes an electrical switch (not shown) which is normally open but closes when the associated push button is pressed downwardly to control one of the above operating modes of the handpiece  10 . Since the assemblies  26   a - 26   d  are conventional they will not be described in further detail. The electrical circuit  20  contains electronics that respond to the closing of the switch assemblies  26   a,    26   b,    26   c,  and  26   d  and send a corresponding signal to the motor  10   a , via the electrical conductors of the cable assembly  14 , to control one of the above-mentioned operational modes.  
      In operation, the surgeon attaches a cutting tool to the handpiece  10  and manually presses, or forces, the pedal  18  downwardly with his or her foot or hand. This closes the switch  18   a  and thus allows the electrical energy from the source  22  to flow to the motor  10   a,  via the electrical circuit  20  and the cable assembly  14 , to activate the motor. Each push button assembly  26   a - 26   d  can be selectively activated by pressing it downwardly in the above manner to control one of the above-mentioned operational modes of the handpiece  10 .  
      Thus, the arrangement of the present invention provides for activation and control of the operation of the handpiece  10  without the need for a console. Also, the above embodiment is relatively easy to set up, is mobile, and requires only a single cable assembly. Further, the electrical energy source and the control electronics are located in the housing that contains the pedal, which does not have to be autoclaved.  
     Variations  
      It is understood that several variations may be made in the foregoing without departing from the scope of the invention including the following. 
          (1) The pedal  18  and its associated switch  18   a  are not limited to the particular types described above but rather can be one of many other conventional designs such as multi-pedal, snap action, slow action, potentiometer, air switch, etc., and can function to include maintained contact, single stage, two stage, three stage, mechanical interlock, and variable stage. Also the switch  18   a  can include two or more momentary type contacts which are sequentially activated as the pedal  18  is pressed.     (2) The movement of the tool that is attached to the handpiece  10  is not limited to a rotation, but rather can be an oscillation or reciprocation, and the like, or can use a water jet, or the like.     (3) The switch  18   a  and the switches associated with the assemblies  26   a - 26   d  can be connected in electrical circuitry that is normally closed and opened when the pedal and the associated push button assembly is pressed down in the above-described manner.     (4) The electrical circuit  20  may be contained in the handpiece  10  rather than in the base member  16 .     (5) The push-button/switch assemblies  26   a - 26   d  can vary in number, depending on the number of operating modes desired, and can even be eliminated.     (6) Although the energy source  22  would typically be a reusable or rechargeable energy source, such as a battery, is could also be in the form of a disposable energy source.     (7) When replacement, reusable or rechargeable, or primary/disposable energy sources, such as the types of batteries discussed above, are not available, it would be possible to provide electrical power via an AC to DC power converter module, which would receive 120 volt AC power and convert it to the appropriate voltage for the surgical device. A cabled plug or jack from the converter would plug into a receiving plug on the base member  16 .     (8) An embedded display could be incorporated into the base member  16  for status conditions (battery management, motor condition), surgeon preferred device settings, and/or current speed.     (9) Rather than have one pedal (18), the assembly  12  can include multiple pedals for providing separate functions of the type discussed above, in which case the number of buttons could be reduced.     (10) The pedal  18  and the push button assemblies  26   a - 26   d  can be either foot or hand operated.     (11) The energy source can be a hybrid layer capacitor, rather than a battery.        

      The preceding specific embodiments are illustrative of the practice of the invention. It is to be understood, therefore, 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. For example, the present invention is not limited to any particular power driven surgical tool and further includes within its scope methods of making and using the system described hereinabove.  
      In the 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.