Patent Document

CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This is a divisional of prior U.S. application Ser. No. 12/658,300, filed Feb. 9, 2010, which claims the benefit of U.S. Provisional Application Serial No. 61/210 311, filed Mar. 17, 2009, the disclosures of which are hereby incorporated by reference in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention is related generally to an electrosurgical system having a controller for selectively changing the intensity of power applied to an electrosurgical probe in a cutting mode and providing a constant power to the probe in a coagulation mode. The system can include a mechanically powered tool that shares a control console with the electrosurgical probe. 
       BACKGROUND OF THE INVENTION 
       [0003]    Endoscopy in the medical field allows internal features of the body of a patient to be viewed without the use of traditional, fully-invasive surgery. Endoscopic imaging systems enable a user to view a surgical site and endoscopic cutting tools enable non-invasive surgery at the site. For instance, an RF generator provides energy to a distal end tip of an RF probe within the surgical site. In one mode, the RF probe provides RF energy at a power level to ablate or otherwise surgically remove tissue. In another instance, RF energy is provided to the RF probe in order to coagulate the tissue at the surgical site to minimize bleeding thereat. 
         [0004]    Tissue ablation is achieved when a high power electrical signal having a sufficiently large voltage is generated by a control console and directed to an attached probe. Application of the high power signal to the probe results in a large voltage difference between the two electrodes located at the tip of the probe (presuming a bipolar probe), with the active electrode being generally 200 volts more than the passive or return electrode. This large voltage difference leads to the formation of an ionized region between the two electrodes, establishing a high energy field at the tip of the probe. Applying the tip of the probe to organic tissue leads to a rapid rise in the internal temperature of the cells making up the neighboring tissue. This rapid rise in temperature near instantaneously causes the intracellular water to boil and the cells to burst and vaporize, a process otherwise known as tissue ablation. An electrosurgical “cut” is thus made by the path of disrupted cells that are ablated by the extremely hot, high energy ionized region maintained at the tip of the probe. An added benefit of electrosurgical cuts is that they cause relatively little bleeding, which is the result of dissipation of heat to the tissue at the margins of the cut that produces a zone of coagulation along the cut edge. 
         [0005]    In contrast to tissue ablation, the application of a low power electrical signal having a relatively low voltage to the active electrode located at the tip of the probe results in coagulation. Specifically, the lower voltage difference established between the active and return electrodes results in a relatively slow heating of the cells, which in turn causes desiccation or dehydration of the tissue without causing the cells to burst. 
         [0006]      FIG. 1  corresponds to  FIG. 1  of U.S. Patent Publication No. 2007/0167941, owned by the same assignee hereof, the disclosure of which is hereby incorporated by reference. 
         [0007]    As illustrated in  FIG. 1 , a typical electrosurgical system  10  includes an electrosurgical probe  12  (hereafter referred to simply as “probe”) and a control console or controller  14 . Interface  15  enables configuration of various devices connected to the console  14 . The probe  12  generally comprises an elongated shaft  16  with a handle or body  18  at one end and a tip  20  at the opposite end. A single active electrode  19  is provided at the tip  20  if the probe  12  is of a “monopolar” design. Conversely, the probe  12  may be provided with both an active electrode  19  and a return electrode  21  at the tip  20  if the probe is “bipolar” in design. The probe  12  connects to control console  14  by means of a detachable cable  22 . The current for energizing the probe  12  comes from control console  14 . When actuated, the control console  14  generates a power signal suitable for applying across the electrode(s) located at the tip  20  of the probe  12 . Specifically, current generated by the control console  14  travels through the cable  22  and down the shaft  16  to tip  20 , where the current subsequently energizes the active electrode  19 . If the probe  12  is monopolar, the current will depart from tip  20  and travel through the patient&#39;s body to a remote return electrode, such as a grounding pad. If the probe  12  is bipolar, the current will primarily pass from the active electrode  19  located at tip  20  to the return electrode  21 , also located at tip  20 , and subsequently along a return path back up the shaft  16  and through the detachable cable  22  to the control console  14 . 
         [0008]    After configuration of the control console  14  is carried out by means of the interface  15 , actuation and control of the probe  12  by the surgeon is accomplished by one or more switches  23 , typically located on the probe  12 . One or more remote controllers, such as, for example, a footswitch  24  having additional switches  25 - 28 , respectively, may also be utilized to provide the surgeon with greater control over the system  10 . In response to the surgeon&#39;s manipulation of the various switches  23  on the probe  12  and/or remote footswitch  24 , the control console  14  generates and applies various low and high power signals to electrode  19 . 
         [0009]    Actuation of coagulation switch  26  of footswitch  24  results in coagulation of the tissue adjacent the tip  20  of the probe  12 . While operating in coagulation mode, the control console  14  of the prior art system shown in  FIG. 1  is configured to drive the electrosurgical probe at a low, but constant, power level. Due to inherent varying conditions in tissue (i.e., the presence of connective tissue versus fatty tissue, as well as the presence or absence of saline solution), the impedance or load that the system experiences may vary. According to Ohm&#39;s law, a change in impedance will result in a change in current levels and/or a change in voltage levels, which in turn, will result in changing power levels. If the operating power level of the system changes by more than a predefined amount, the control console  14  will attempt to compensate and return the power back to its originally designated level by regulating either the voltage and/or current of the power signal being generated by the console and used to drive the attached probe  12 . 
         [0010]    Electrosurgical systems  10  also have a cutting mode for cutting tissue. Actuation of cutting switch  25  of the footswitch  24  places the electrosurgical system  10  in the cutting or ablation mode by application of a high energy signal to probe  12 . In the cutting mode, the controller  14  outputs constant energy to the electrosurgical probe  12  while an operator maintains at least a predetermined force to actuate the cutting switch  25 . 
         [0011]    In a cutting operation, to change the power level of energy applied to the electrosurgical probe  12 , the cutting switch  25  must be off. Then a user actuates either of switches  27 ,  28  on the footswitch  24 , which function as controls for increasing and decreasing the power intensity output level, respectively. The electrosurgical system  10  senses actuation of increase switch  27  for increasing the power intensity value for output by the control console  14  depending on the original intensity value setting and the number of times the switch  27  is pressed. Likewise the electrosurgical system senses actuation of decrease switch  28  for decreasing the power intensity value from a previous value. Then, upon actuation of switch  25 , the RF generator in the console  14  applies power to the probe  12  at the newly selected power level. 
         [0012]    While the system shown in  FIG. 1  adjusts cutting energy that is output from an RF generator in the control console  14 , the changes in power level are made while the RF generator is off. Thus, a cutting operation must be interrupted or discontinued to change the power level.  FIG. 2  shows one example wherein eleven separate discrete power levels are selectable for an electrosurgical system. Turning off energy to the electrode  19  to change power levels increases the length of time required to perform a surgery, which can be detrimental to the patient. 
         [0013]    In the electrosurgical system  10  shown in  FIG. 1 , a non-volatile memory device (not shown) and reader/writer (not shown) can be incorporated into the handle  18  of the electrosurgical probe  12 , or alternatively, incorporated into or on the cable  22  that is part of the probe  12  and which is used to connect the probe  12  to the control console  14  of the system. Alternatively, the memory device may be configured so as to be incorporated into or on the communication port that is located at the free end of the cable  22  and which is used to interface the cable with a corresponding port on the control console  14 . 
         [0014]    During manufacturing of the probe shown in  FIG. 1 , data representing probe-specific operating parameters is loaded into the memory device. Upon connection of the probe  12  to the control console  14  of the electrosurgical system  10 , the data stored in the probe&#39;s non-volatile memory can be accessed by a reader and forwarded on to the control console  14 . As such, once an electrosurgical probe  12  is connected, the control console  14  accesses the configuration data of the specific probe  12  and automatically configures itself based on the operating parameters of the probe. 
         [0015]    Beyond probe-specific operating parameters, the memory device within each attachable probe  12  can store additional data concerning usage of the probe. This usage data includes a variety of information. For example, usage data may represent the number of times an electrosurgical probe  12  has been used, or the duration of the time that the probe has been activated overall or operated at different power levels. Additional usage data may restrict the amount of time that a specific attachable probe can be used. In addition to usage data, the prior art memory device can store information concerning any errors that were encountered during use of the probe  12 . 
         [0016]    One embodiment of the invention is directed to a system for an electrosurgical probe that dynamically adjusts power output from the probe without deactivating and then reactivating an RF generator. This arrangement can minimize the length of time for an operating procedure. 
         [0017]    One embodiment of the invention disclosed herein is directed to improving cutting of tissue by an electrosurgical probe, such as by manually adjusting or varying the intensity of power delivered to tissue by a generator without temporarily interrupting the application of power. This arrangement also includes an actuator for coagulating tissue at a constant power level. 
         [0018]    In another embodiment of the invention, operation of an electrosurgical system is obtained by providing a controller to vary the intensity of power applied to an electrosurgical probe without disruption in a first variable mode, and by providing a second fixed mode wherein energy to the RF probe is discontinued to allow a user to change the power level. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  depicts an electrosurgical system that includes an electrosurgical probe connected to a control console, along with a footswitch. 
           [0020]      FIG. 2  is a graph showing output power at a plurality of set points having corresponding different power levels. 
           [0021]      FIG. 3  depicts an electrosurgical system of the invention that includes a foot controller, an electrosurgical probe and a powered surgical handpiece for attachment to a control console. 
           [0022]      FIG. 4  is a block diagram of the electrosurgical system. 
           [0023]      FIG. 5  is a top perspective view of the foot controller shown in  FIG. 3 . 
           [0024]      FIG. 6  is a flow chart showing steps for controlling power to an electrosurgical probe depending on selected operating modes. 
           [0025]      FIG. 7  is a flow chart for a variable mode subroutine that provides varying power levels to an electrosurgical probe without discontinuing power to the probe. 
           [0026]      FIG. 8  illustrates a graph showing delivered power versus percentage of pedal press of an actuator. 
           [0027]      FIG. 9  is a flow chart for a fixed mode subroutine that requires no application of power to an electrosurgical probe to change a power level value. 
           [0028]      FIG. 10  is a tool/probe routine which includes selecting the device to be operated. 
           [0029]      FIG. 11  is a flow chart showing a second embodiment for controlling an electrosurgical probe. 
           [0030]      FIG. 12  is a flow chart of a cutting subroutine for the embodiment of  FIG. 11 . 
       
    
    
     DETAILED DESCRIPTION 
       [0031]      FIG. 3  shows a surgical system  30  including a console  32  having a visual display screen  33 , a footswitch receiving port  34 , a handpiece receiving port  36 , an RF probe receiving port  38  and control console selectors. The visual display screen  33  displays devices connected to the receiving ports  36 ,  38 . The display screen  33  is capable of displaying a plurality of modes for selection in response to actuation of selected ones of the console selectors. The footswitch receiving port  34  provides a connection to the control console  32  for a foot controller  40 . Handpiece receiving port  36  receives the connection jack of a powered surgical handpiece  42  with a cutting element attached thereto, for instance a mechanical cutting tool or cutting element  43 , such as a burr. The powered surgical handpiece  42  can control oscillation or rotation speed of the mechanical cutting tool  43  secured thereto in response to actuation of the foot controller  40 . RF probe receiving port  38  receives a connecting jack of an RF or electrosurgical probe  44  having an electrode  46 . In some embodiments, control console selectors include push buttons that control or scroll through menus shown on the visual display screen  33  of the control console  32 . In some instances, one or more of the selectors select user preferences for particular operating modes of the surgical handpiece  42  with a mechanical cutting element  43 , such as a burr secured thereto or the electrosurgical probe  44  of the surgical system  30 . 
         [0032]    The handpiece  42  of the surgical system  30  includes a transceiver (not shown) and a non-volatile memory device (not shown). The transceiver acts as a reading device for reading cutter-specific data from the cutting element  43 . 
         [0033]    One embodiment of the RF probe structure generally corresponds to the probe structure illustrated in  FIG. 1 , except additional probe-specific data, described later herein, is provided on a one-wire memory  48  as shown in  FIG. 4  for reading by the control console  32 . The control console  32  includes a processing device  50  for processing the data received from the one-wire memory device  48 . The processing device  50  shown in  FIG. 4  controls an RF generator  52  that provides RF energy to the electrosurgical probe  44  to power the electrode  46  disposed at the distal end thereof. 
       Controller 
       [0034]    The foot controller  40  illustrated in  FIGS. 3-5  is similar in structure to the remote console disclosed in U.S. Patent Publication No. 2006/0116667, owned by the same assignee hereof, the disclosure of which is hereby incorporated by reference. 
         [0035]    As shown in  FIG. 5 , the foot controller  40  includes a device selection actuator  56 , a power decrease actuator  58  and a power increase actuator  60 . The device selection actuator  56  chooses between a powered surgical handpiece  42  and an electrosurgical probe  44  that are connected to the control console  32  for operation thereof. Further, the controller  40  includes a cutting power actuator  62  and a coagulation actuator  64  for operating the electrosurgical probe  44  when the probe is selected. In the fixed cutting mode, the actuator  62  acts as a switch that enables cutting by the electrosurgical probe  44 . In the variable cutting mode, the actuator  62  provides a changing output value depending on the total force applied thereto. Detailed operation of the foot controller  40  for the surgical system  30  is discussed below. 
       Electrosurgical Probe Routine 
       [0036]      FIG. 6  is a flow chart representing an electrosurgical probe routine  68  for a processing device  50  operating the RF generator  52  that supplies power to the electrosurgical probe  44 . In one embodiment of the invention, selectors of the control console  32  enable an operator to select between a variable mode and a fixed mode for operation of the electrosurgical probe  44 . 
         [0037]    The probe routine  68  illustrated in  FIG. 6  begins at start  70 . A user selects the variable mode or the fixed mode. Further, other modes for selection, such as a device configuration mode are contemplated. In another embodiment, a user selects a menu entry that initializes settings of the surgical system  30  using the stored preference information for a particular user. In other embodiments, a selection switch is provided to select the operating mode. 
         [0038]    At step  72 , the processing device  50  determines if the variable mode or the fixed mode has been selected. If the variable mode is chosen by a user, the processing device advances to step  74 . 
       Variable Mode Subroutine 
       [0039]    When variable mode subroutine  74  is selected, the processing device  50  executes the variable subroutine illustrated in  FIG. 7 . From start  76 , the variable mode subroutine  74  advances to coagulation decision step  78 . If the coagulation actuator  64  provides a coagulation signal, the processing device  50  advances to step  80  and outputs a constant predetermined power value from the RF generator  52 . The RF generator  52  provides the constant predetermined coagulation power value to the electrosurgical probe  44  to coagulate tissue. The processing device  50  then returns to decision step  78  and determines if the coagulation actuator  64  continues to be pressed. 
         [0040]    In the instance when the coagulation actuator  64  is not depressed, the variable mode subroutine  74  of the processing device  50  advances to step  82 . At step  82 , the processing device  50  determines whether the dual purpose power actuator  62  is depressed, and if depressed, a measured force or control value from the dual purpose power actuator  62  is provided to the processing device  50 . At step  83 , depending on the amount of force applied to the actuator  62 , such as a foot pedal, the processing device  50  controls the RF generator  52  to output a discrete power level from the electrosurgical probe  44  that is proportional with respect to the measured force or sensed control value received from the actuator  62 . So long as the actuator  62  is depressed, at decision step  82  the routine advances to execute at step  83  and then returns to step  82  of the variable mode subroutine  74  and repeats same. When the actuator  62  is not depressed at decision step  82 , the variable mode subroutine  74  advances to return  84  and the variable mode subroutine ends. 
         [0041]    The variable mode enables an operator to select from the various power level outputs illustrated in  FIG. 8  while being capable of providing different power levels to the electrosurgical probe  44  without first discontinuing power to the probe. The pedal press or force applied to the actuator  62  provides essentially instantaneous variable power control of the power output from the RF generator  52 . As shown in the embodiment of  FIG. 8 , the percentage of applied pedal force/pressure or pedal travel extends from 0% to 100% and corresponds to eleven different discrete power levels or values that depend on the force applied to the actuator  62 . In another embodiment, the amount of movement of a pedal of the actuator  62  controls the power level provided by the RF generator  52 . 
         [0042]    Returning to  FIG. 6 , when the power actuator  62  no longer receives at least a predetermined force, the processing device  50  advances to probe reset decision step  90 . At step  90 , the processing device  50  determines if a selector of the control console  32  has been operated to select the other electrosurgical probe operating mode, a configuration routine or other operating mode for execution by processing device  50 . If one of the electrosurgical probe mode subroutines  74 ,  92  is or remains selected, the processing device  50  advances to step  72 . 
         [0043]    In one embodiment, the actuator  62  includes a hall effect sensor that determines the movement or position of a pedal of the actuator and controls the power levels as illustrated in  FIG. 8 . Further, in some embodiments the actuator  62  is a force transducer or pressure transducer for sensing force applied thereto, without necessarily having significant movement of a foot pedal or other element thereof. In these embodiments the power level output can be linear with respect to the force applied to the pedal of the actuator  62 . In other embodiments the power level output is non-linear with respect to the force applied to the pedal. 
         [0044]    In some embodiments the actuator  62  is a position sensor including a series of position responsive switches actuated in response to the amount of movement of a pedal of the actuator to provide a linear increase in the power level with respect to movement of the pedal. In some embodiments the power level output is non-linear with respect to foot travel distance or movement of the actuator  62 . 
         [0045]    While  FIG. 8  shows eleven discrete power levels for the variable mode of operation, fewer or more power levels can be provided. For example, in some embodiments twenty or more power levels are correlated with the force applied to the actuator  62  and provided to processing device  50  to obtain a more precise output power level control. As discussed above, the variable mode results in less cutting delay and thus a less time consuming surgical procedure. 
         [0046]    In some embodiments, a default to the variable mode or to the fixed mode for the electrosurgical probe  44  is provided when the surgical system  30  is initially powered on. 
       Fixed Mode Subroutine 
       [0047]    At decision step  72  in probe routine  68  shown in  FIG. 6 , if the variable mode is not indicated at decision step  72 , the processing device  50  advances to fixed mode subroutine  92  shown in  FIG. 9 . 
         [0048]    The fixed mode subroutine  92  shown in  FIG. 9  executes by advancing from start  94  to coagulation decision step  96 . In the fixed mode subroutine  92 , if the coagulation actuator  64  is depressed, the processing device  50  advances to step  98 . At step  98 , the processing device  50  operates to provide an essentially constant coagulation power value from the RF generator  52  to the electrosurgical probe  44 . As shown in  FIG. 9 , from step  98 , the processing device  50  returns to coagulation decision step  96 . At step  96 , if the coagulation actuator  64  is not actuated, the coagulation power value is no longer output and the processing device  50  advances to step  100 . 
         [0049]    At step  100 , the processing device determines if any of actuators  58 ,  60  and  62  are depressed. If actuator  62  is depressed, the RF generator  52  provides power to the electrosurgical probe  44  at an initial power value or level provided at system start-up or at a power level previously set by a user operating the control console  32 . If the actuator  62  is depressed to enable power to the electrosurgical probe  44 , actuators  58 ,  60  are disabled and do not function. Thus the power level provided by the RF generator  52  to the electrosurgical probe  44  remains essentially constant. 
         [0050]    At step  100 , if power increase actuator  60  is depressed with actuator  62  not operative, the discrete power level to be output by the RF generator  52  is increased. In some embodiments, the power level increases in a manner corresponding to the various set points for discrete power level as shown in  FIG. 2 , for each actuation of actuator  60  that is sensed by foot controller  40  and provided to the processor device  50 . 
         [0051]    If the power decrease actuator  58  is operated at step  100  with actuator  62  not operative, the discrete power level value is decreased for each actuation thereof. The power level decreases in a manner generally corresponding to the various set points for discrete power level as illustrated, for example, in  FIG. 2  for each actuation of the actuator  58 . At return step  102 , the fixed mode subroutine  92  returns to the electrosurgical probe routine  68  shown in  FIG. 6 . 
       Tool/Probe Routine 
       [0052]      FIG. 10  is a flow chart directed to a tool/probe routine  108  for the processing device  50 . The routine  108  begins at start  110  and advances to a tool decision step  112 . When tool operation is selected at decision step  112 , the processing device  50  advances to tool routine  114 . Tool routine  114  is a known method of operating the cutting element  43  mounted to the powered surgical handpiece  42 . U.S. Patent Publication No. 2006/0116667 discloses an arrangement wherein various elements are operated with one controller. Thus, the tool routine  114  will not be discussed in detail herein. 
         [0053]    In tool routine  114 , the actuators on the foot controller  40  control the powered surgical handpiece  42  to power a cutting element  43  to cut tissue. After tool routine  114 , operation of the processing device  50  advances to decision step  116 . At step  116 , if a different device or mode is not selected, the processing device  50  returns to tool routine  114  and continues to operate the mechanical cutting tool or cutting element  43  that is mounted to the powered handpiece  42 . 
         [0054]    When a device reselection has been determined at step  116 , the processing device  50  returns to tool decision step  112 . At tool decision step  112 , if the tool is not selected, the processing device  50  advances to probe decision step  115 . If an electrosurgical probe operation is selected by the actuator  56 , the processing device  50  advances to electrosurgical probe routine  68  illustrated in  FIG. 6 . The probe routine  68  operates as discussed above until electrosurgical probe operation is discontinued as illustrated at step  120  in  FIG. 6  and can eventually return to the tool decision step  112  illustrated in  FIG. 10 . 
         [0055]    In  FIG. 10 , if the electrosurgical probe is not selected at decision step  115 , the processing device  50  can advance to select state  124 . 
         [0056]    The term “select state” references a state wherein a large number of additional modes can be operated, such as configuration modes or the like. 
         [0057]    One mode, as discussed in  FIG. 1 , includes reading of one-wire memory devices  48  or reading of RFID chips disposed in the electrosurgical probe  44  or in the powered surgical handpiece  42 . Such data is received by the processing device  50  and stored therein to assist in operation thereof. For instance, data related to the operating parameters of the cutting element  43  mounted to the powered surgical handpiece  42 , or related to the electrosurgical probe  44  having an electrode  46 , may be stored by the processing device  50  to ensure proper operation thereof. 
         [0058]    In other embodiments, additional operating modes or subroutines enable control of both the cutting element  43  and electrode  46  simultaneously with actuators on at least one of the handpiece  42 , the electrosurgical probe  44  and the control console  32 , along with the controller  40 . 
       Alternative Electrosurgical Probe Routine 
       [0059]      FIG. 11  is a flow chart representing a second embodiment of an electrosurgical probe routine. The electrosurgical probe routine  200  shown in  FIG. 11  is executed by processing device  50  to control the RF generator  52  that supplies power to the electrosurgical probe  44 . The electrosurgical probe routine  200  begins at start  202 . In one embodiment, at start  202  the processing device  50  already has stored therein available default preferences for a particular user with regard to pre-selection of the variable or fixed operating mode and properties of the particular electrosurgical probe  44  connected to the console. 
         [0060]    From start  202 , the routine  200  advances to coagulation decision step  204 . The processor  50  determines if the coagulation actuator  64  is enabled. If so, the processor  50  advances to step  206 . At step  206 , the processor  50  controls the RF generator  52  to supply coagulation power to the electrosurgical probe  44  so long as the actuator  64  is enabled. When the actuator  64  is disengaged, the processor  50  advances to return step  208  and returns to start  202 . 
         [0061]    Returning to coagulation decision step  204 , when the processor  50  determines that the coagulation actuator  64  is not enabled, the probe routine  200  advances to increase power level decision step  210 . At decision step  210 , the processor  50  determines if the power increase actuator  60  is enabled. When the power increase actuator  60  is enabled, the routine  200  advances to step  212 . At step  212 , the stored power level value for the cutting operation is increased or incremented by a discrete power level value. 
         [0062]    In some embodiments, if the discrete power level is at a maximum value and thus cannot be further increased, enabling of the power increase actuator  60  selects the fixed cutting mode for operation instead of the variable cutting mode or maintains the fixed cutting mode. In other embodiments, the processor  50  changes the electrosurgical probe arrangement from the fixed cutting mode to the variable cutting mode, or remains in the variable cutting mode, when the power increase actuator  60  is enabled while at the maximum power level value. 
         [0063]    After the power increase actuator  60  is disengaged, the processor  50  advances to return step  214  and returns to start  202 . 
         [0064]    Returning to decision step  210  shown in  FIG. 11 , when the processor  50  determines that the power increase actuator  60  is not enabled, the routine  200  advances to decrease power level decision step  216 . At decision step  216 , the processor  50  determines if the power decrease actuator  56  is enabled. When the power decrease actuator  56  is enabled, the probe routine  200  advances to step  218 . At step  218 , the power level value for the cutting operation is decreased by a discrete power level value. When the decrease actuator  56  is disabled, the routine  200  advances to return step  220  and then returns to start step  202 . 
         [0065]    Returning to decision step  216 , when the power decrease actuator  56  is not enabled, the electrosurgical probe routine  200  advances to cutting subroutine  230  shown in  FIG. 12 . The cutting subroutine  230  begins at block  232  shown in  FIG. 12  which represents a NO output from decision step  216  of the electrosurgical probe routine  200  shown in  FIG. 11 . 
         [0066]    In the cutting subroutine  230 , the processor  50  advances from block  232  to cutting decision step  234 . At decision step  234 , the processor  50  determines if the cutting actuator  62  is enabled. When the cutting actuator  62  is not enabled, the processor  50  advances to return step  236  and returns to start step  202  illustrated in  FIG. 11 . 
         [0067]    When the cutting actuator  62  is actuated, the processor  50  advances from cutting decision step  234 , to variable mode decision step  238 . At decision step  238 , the processor  50  determines if the electrosurgical probe arrangement is set in the variable operating mode. 
         [0068]    In some embodiments, variable mode is preset for the console as a user preference at start up of the control console  32 . As discussed above, in some embodiments the power increase actuator  60  selects the variable mode. In other embodiments, a separate actuator (not shown) selects between the variable and fixed operating mode for the electrosurgical probe  44 . 
         [0069]    At the variable mode decision step  238 , when the processor  50  determines that the variable mode has been set or selected, the cutting subroutine  230  advances to variable cut step  240  to provide a variable power output from the RF generator  52  to the electrosurgical probe  44  so long as the cutting actuator  62  is operated. 
         [0070]    As discussed in the first embodiment shown in  FIGS. 6 ,  7  and  9 , the cutting power actuator  62  can vary the power from a low value to a maximum value based upon measurement of the force applied thereto. In another embodiment, movement of the actuator  62  against a biasing device, such as a spring element, controls the amount of power supplied from the RF generator  52  to the electrosurgical probe  44 . In some embodiments, the power decrease actuator  58  and the power increase actuator  60  can select a maximum power value for use during variable operation of the electrosurgical probe  44 . 
         [0071]    When the cutting power actuator  62  is disabled, power output by the RE generator  52  is discontinued and the processor  50  advances to return step  242 . At step  242 , the cutting subroutine  230  returns to start block  202  of the probe routine  200  illustrated in  FIG. 11 . 
         [0072]    Returning to decision step  238 , when the processor  50  determines the electrosurgical arrangement is not in the variable mode, the processor  50  advances to constant power level cutting step  244 . At cutting step  244 , the RF generator  52  provides the pre-selected constant power level to the electrosurgical probe  44  until the cutting power actuator  62  is deactivated. After deactivation, the RF generator  52  stops providing power and the processor  50  advances to return step  246 . At step  246 , the cutting subroutine  230  returns to start step  202  of the probe routine  200  illustrated in  FIG. 11 . 
       Alternatives 
       [0073]    While the above embodiments disclose a specific control pattern or function for each of the actuators  56 ,  58 ,  60 ,  62 ,  64  on the controller  40 , which in this embodiment is a foot controller, other embodiments of actuators provided on a controller  40  are contemplated. In some embodiments, the actuators are repositioned or the functions of specific individual actuators on a foot controller can be changed. 
         [0074]    As set forth above, the actuator  62  enables power to the electrosurgical probe  44  in both a variable mode and a fixed mode. Thus, the actuator  62  may be considered a variable/fixed mode power actuator. In some embodiments, other actuators provide the same, different, or multiple functions. 
         [0075]    While  FIGS. 4 and 5  only show a foot operated controller  40 , other embodiments are contemplated. For instance, the electrosurgical probe  44  illustrated in  FIG. 3  may have a grouping of three or more actuators disposed thereon that perform essentially the same functions as the actuators on the foot controller  40 . Further, in another embodiment, the actuators illustrated in  FIG. 5  are provided as control buttons on the control console  32  as illustrated in  FIG. 3 . 
         [0076]    In some embodiments, various actuators disposed on the controller  40  or disposed on the electrosurgical probe  44  may perform similar functions or share control of the electrosurgical probe. In one embodiment, an operator utilizes the foot controller  40  to select a variable power cutting mode or a fixed power cutting mode. Then, one of the actuators on the electrosurgical probe  44  shown in  FIG. 3  is operated to provide various discrete power levels to the electrode  46  in a similar manner as the actuators disposed on the foot controller  40 . 
         [0077]    In some embodiments the control console  32  provides an audible and/or visual indication of the selected device and the selected mode. 
         [0078]    While  FIGS. 2 and 8  disclose power values at various settings, in some embodiments a power value corresponds to an output voltage value that essentially remains constant regardless of the output resistance or load of the electrosurgical probe  44  and the electrode  46 . Thus, throughout the instant specification and claims, terms such as discrete power level, power value, fixed power, variable power and the like are intended to include predetermined voltage values or voltage levels output by the RF generator  52 . 
         [0079]    The routines and subroutines illustrated in  FIGS. 6 ,  7  and  9 - 12  are for purposes of describing various embodiments of the invention. Additional embodiments of the invention are contemplated wherein the routines and subroutines operate in a different order and/or have additional steps that provide similar operating results as the specific routines and subroutines disclosed herein. 
         [0080]    Although particular preferred embodiments of the invention are disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangements of parts, lie within the scope of the present invention.

Technology Category: 1