Patent Publication Number: US-10780265-B2

Title: Drill assembly for accessing bone

Description:
RELATED APPLICATION 
     The present application is a continuation patent application and claims priority benefit, with regard to all common subject matter, of earlier-filed U.S. patent application Ser. No. 14/948,603, filed Nov. 23, 2015, entitled “DRILL ASSEMBLY FOR ACCESSING BONE,” and now issued as U.S. Pat. No. 10,118,029 on Nov. 6, 2018 (“the &#39;029 Patent”). The &#39;029 Patent is a continuation patent application and claims priority benefit, with regard to all common subject matter, of earlier-filed U.S. patent application Ser. No. 14/230,534, filed Mar. 31, 2014, entitled “SYSTEM AND METHOD FOR STABILIZING IMPLANTED SPINAL CORD STIMULATORS,” and now issued as U.S. Pat. No. 9,192,759 on Nov. 24, 2015 (“the &#39;759 Patent”). The above-referenced patents are hereby incorporated by reference into the present application in their entirety. 
    
    
     BACKGROUND 
     1. Field 
     Embodiments of the invention provide a system and method for stabilizing implanted spinal cord stimulators implanted in the epidural space of a spinal cord of a patient. 
     2. Related Art 
     Spinal cord stimulators (“SCSs” or “stimulators”) output electrical pulses to control chronic back pain. The stimulator generally comprises an implantable pulse generator (IPG), a plurality of implanted stimulating electrodes, and conducting lead wires connecting the electrodes to the generator. The electrodes are positioned on a lead that is implanted in the epidural space of the spinal column proximate the spinal cord, and multiple leads may be implanted. The IPG is implanted subcutaneously proximate the lumbar region of the back and includes a power supply and remote controls. The electrodes commonly come in two forms—percutaneous form and paddle form. Embodiments of the invention are primarily directed to percutaneous type electrodes. The lead wires are coupled to the percutaneous leads having an array of electrodes and are fed through the spinal column and to the IPG implanted in the lumbar region. A patient can then control an amount of voltage and current exerted by the electrodes to address chronic pain or other disorders. 
     Percutaneous electrodes comprise a very long, thing wire (also known as a “lead wire” or “lead line”) connected to the lead(s). A plurality of leads may extend from the single wire, or multiple wires with one or more leads may be implanted in the epidural space. Because the percutaneous electrodes extend axially through the spinal column, the electrodes are susceptible to axial movement within or dislodgement from the spinal column when the patient moves. This may be undesirable if the electrodes move out of position relative to the location where the voltage should be applied. 
     SUMMARY 
     Embodiments of the invention relate to spinal cord stimulators and systems and methods for implanting the stimulators and preventing or limiting axial movement of the stimulators once implanted in a patient&#39;s epidural space of the spinal column. Embodiments of the invention are specially adapted for use with percutaneous leads, although embodiments may be used with paddle stimulators. The stimulators generally comprise at least one lead and at least one lead wire connected to the lead. The system of embodiments of the invention broadly comprises a drill assembly, a guide wire assembly, and a guide wire receiver. The drill assembly includes a cannula, a drill, and an incremental drill adjuster. The guide wire assembly includes a hollowed guide wire sleeve presenting a guide wire sleeve lumen and a guide wire housed within the sleeve lumen. A magnet is disposed on a proximal end of the guide wire assembly. 
     The cannula has a handle and a hollowed cannula shaft coupled to and extending from the handle. The hollowed cannula shaft presents a cannula lumen. The drill has a drill handle and a hollowed drill shaft presenting a drill lumen, wherein the drill shaft has proximal and distal ends. A drill bit is provided on the proximal end of the shaft, and the drill shaft is configured to be inserted in the cannula lumen. The incremental drill adjuster is configured to advance the drill shaft by a pre-set distance upon rotation of the drill handle by 360 degrees or other pre-set rotation angle. 
     The guide wire receiver comprises a handle and an elongated shaft, and the shaft has a handle end coupled to the handle and a receiving end opposite the handle end. The guide wire receiver shaft is semi-cylindrical along a portion of its length to present an open lumen, and at least a portion of the open lumen at the receiving end of the shaft is widened to provide a scoop for receipt of the magnet on the proximal end of the guide wire assembly. 
     The above components, in addition to other components not discussed above in this brief summary, are utilized in the method of embodiments of the invention. The method of embodiments of the invention broadly comprises the below-discussed steps. First, a surgeon accesses the patient&#39;s epidural space at the lumbar region of the patient to create a first access point and accesses the user&#39;s epidural space at the thoracic region of the patient to create a second access point. The epidural space is accessed at the thoracic region using the drill assembly. In contrast, the epidural space at the lumbar region may be accessed using the drill assembly or, if penetrating only soft tissue and not bony lamina, a needle and stylet. 
     After creating the first and second access points, the surgeon then inserts the guide wire assembly through the second access point and into the epidural space at the thoracic region of the patient. The guide wire assembly has proximal and distal ends, and the proximal end of the guide wire is an end closest to the patient when the guide wire is inserted through the second access point, and the distal end of the guide wire is opposite the proximal end and closest to a surgeon when the guide wire is inserted through the second access point. The surgeon then inserts the guide wire receiver into the first access point at the lumbar region of the patient. The surgeon captures the guide wire assembly with the guide wire receiver by positioning the proximal end of the guide wire assembly within the scoop of the guide wire receiver. 
     Upon capturing the guide wire assembly via the guide wire receiver, the surgeon pulls, from the lumbar region, the guide wire assembly through the epidural space to expose a portion of the guide wire assembly external to the first access point at the lumbar region. The surgeon then removes the magnet from the guide wire assembly and removes the guide wire housed within the guide wire sleeve lumen. The surgeon feeds at least one monofilament through the guide wire sleeve lumen from one of the lumbar or thoracic regions and to an other of the lumbar or thoracic regions. Once the monofilament is fed through the patient&#39;s epidural space along the axial length of the patient&#39;s back, the surgeon removes the guide wire sleeve from the epidural space and leaves in place the at least one monofilament in the epidural space. A first length of the at least one monofilament is then exposed and external to the first access point, and a second length of the at least one monofilament is exposed and external to the second access point. 
     To insert the percutaneous leads into the epidural space, the surgeon couples one end of the at least one monofilament to an end of a percutaneous lead of a spinal cord stimulator. The surgeon pulls the percutaneous lead through at least a portion of the epidural space of the spinal cord by pulling on an other of the ends of the at least one monofilament to which the percutaneous lead is not coupled. The surgeon then positions the percutaneous lead at the desired position within the epidural space by pulling on said other end of the at least one monofilament until the lead is in said desired position. Finally, the surgeon anchors one of said first or second lengths of the at least one monofilament exposed outside of the one of said first or second access points and anchors the percutaneous lead wire exposed outside of the other of said first and second access points. 
     This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Other aspects and advantages of the present invention will be apparent from the following detailed description of the embodiments and the accompanying drawing figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       Embodiments of the present invention are described in detail below with reference to the attached drawing figures, wherein: 
         FIG. 1  is a schematic view of a patient&#39;s posterior side, including an illustration of the patient&#39;s spinal column and indicating a lumbar region and a thoracic region on the patient; 
         FIG. 2  is an exploded perspective view of a cannula and a trocar of embodiments of the invention; 
         FIG. 3  is an exploded perspective view of a drill assembly of embodiments of the invention, particularly illustrating the cannula, a drill, and a drill stylet; 
         FIG. 4  is a fragmentary perspective view of the drill of  FIG. 3  and particularly illustrating a cutout in a drill handle; 
         FIG. 5  is a perspective view of the drill and drill stylet of  FIG. 3  and particularly illustrating the drill stylet seated within a notch of the drill handle; 
         FIG. 6  is a perspective view of a drill shaft of the drill of  FIG. 3  and illustrating various segments of the shaft; 
         FIG. 7  is a fragmentary front end view of a cannula handle of the cannula of  FIG. 3 , the drill handle, and the drill stylet; 
         FIG. 8  is a cross-sectional view taken through line  7 - 7  of  FIG. 7 ; 
         FIG. 9  is an exploded perspective view of a needle and a needle stylet of embodiments of the invention; 
         FIG. 10  is a fragmentary perspective view of a guide wire assembly of embodiments of the invention and particularly illustrating a guide wire sleeve and a guide wire housed within the sleeve; 
         FIG. 11  is a fragmentary exploded perspective view of the needle and needle stylet of  FIG. 9  and the guide wire assembly of  FIG. 10  housed within the needle stylet; 
         FIG. 12  is an exploded perspective view of an introducer and introducer stylet of embodiments of the invention; 
         FIG. 13  is a perspective view of a guide wire receiver of embodiments of the invention; 
         FIG. 14  is an exploded perspective view of a first angiocath of embodiments of the invention being fed over the guide wire assembly of  FIG. 10 ; 
         FIG. 15  is a fragmentary perspective view of the introducer and introducer stylet combination of  FIG. 12  being fed over the guide wire assembly of  FIG. 10 ; 
         FIG. 16 a    is a first end view of a scoop located on a proximal end of the guide wire receiver of  FIG. 13 ; 
         FIG. 16 b    is a second end view of a scoop located on a proximal end of the guide wire receiver of  FIG. 13 ; 
         FIG. 16 c    is a third end view of a scoop located on a proximal end of the guide wire receiver of  FIG. 13 ; 
         FIG. 16 d    is a first perspective view of the scoop and particularly illustrating the scoop in a fully-folded position; 
         FIG. 16 e    is a second perspective view of the scoop and particularly illustrating the scoop in a fully-open position; 
         FIG. 17  is an exploded perspective view of the guide wire receiver housed within the introducer, and the combined guide wire receiver and introducer being fed into the cannula; 
         FIG. 18  is a fragmentary perspective view of the scoop of the guide wire receiver catching a magnet coupled to the proximal end of the guide wire assembly; 
         FIG. 19  is an exploded perspective view of a second angiocath of embodiments of the invention having a magnet coupled to its proximal end and being fed through the introducer stylet and introducer; and 
         FIG. 20  is a perspective view of a lead wire of a percutaneous stimulator, a connector, and the monofilament of embodiments of the invention. 
     
    
    
     The drawing figures do not limit the invention to the specific embodiments disclosed and described herein. The drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention. 
     DETAILED DESCRIPTION 
     The following detailed description of embodiments of the invention references the accompanying drawings that illustrate specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense. The scope of the invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled. 
     In this description, references to “one embodiment,” “an embodiment,” or “embodiments” mean that the feature or features being referred to are included in at least one embodiment of the technology. Separate references to “one embodiment,” “an embodiment,” or “embodiments” in this description do not necessarily refer to the same embodiment and are also not mutually exclusive unless so stated and/or except as will be readily apparent to those skilled in the art from the description. For example, a feature, structure, act, etc. described in one embodiment may also be included in other embodiments but is not necessarily included. Thus, the present technology can include a variety of combinations and/or integrations of the embodiments described herein. 
     Turning now to the drawings, embodiments of the invention comprise a system and a method for implanting and stabilizing or otherwise securing percutaneous spinal cord stimulators  10 . As shown in  FIG. 20 , the stimulators  10  generally comprise one or more leads  12 , with the one or more leads comprising at least one electrode (not shown) that emits an electrical voltage. The leads  12  are connected to a lead wire  14 , and the lead wire is coupled with an implantable pulse generator  16  (IPG) (see,  FIG. 1 ) that is implanted subcutaneously in a patient&#39;s back. Referring to  FIG. 1 , the patient&#39;s back has a lumbar region or end  18  and a thoracic region or end  20  with the spinal column  22  axially positioned between the two regions. The IPG  16  is normally implanted at the flank region or the lumbar region  18 . A stabilizing system  24  of embodiments of the invention secures the lead  12  within the epidural space of the spinal column  22 . In embodiments, the system  24  broadly comprises a plurality of various medical devices that are used to perform the method of embodiments of the invention. In particular, the stabilizing system  24  comprises a drill assembly  26 , a guide wire assembly  28 , and a guide wire receiver  30 . Other components of the system will be described herein. 
     The following description will reference various orientations of the components of the stabilizing system. Reference to a proximal end of a particular component refers to the end closest to the patient when the component is in use. In contrast, reference to a distal end refers to the end opposite the proximal end and closest to the surgeon using the component. Reference to a vertical axis of a component refers to the axis along the component&#39;s length, and reference to a transverse axis of a component refers to the axis along the component&#39;s width. If the reference directions of “proximal” and “distal” are not suitable for a particular component, such as if the component is within the spinal column, then reference will be made to a thoracic end and a lumbar end, with the thoracic end being the end closest to the thoracic region  20  of the patient (i.e., closer to the patient&#39;s neck), and the lumbar end being the end closest to the lumbar region  18  of the patient (i.e., closer to the patient&#39;s buttocks). Finally, many of the components of the system  24  comprise medical devices that have hollowed shafts. The term “lumen” will be used herein to refer to the hollowed area or bore formed by the respective shaft, and each respective shaft&#39;s lumen will not be given a separate reference numeral. 
     Many, if not most, of the components described herein are radio-opaque so that they can be viewed under X-ray. Unless otherwise stated, it is to be assumed that in embodiments of the invention, a component is radio-opaque. 
     Turning now to  FIGS. 2-8 , the drill assembly  26  of embodiments comprises a cannula  32 , a drill  34 , and an incremental drill adjuster  36 . The cannula  32  comprises a cannula handle  38  and a cannula shaft  40  that is hollowed to present a cannula lumen. A trocar  42  having a trocar cap  44  and pointed shaft  46  is configured to fit within the cannula lumen. A proximal end  48  of the pointed shaft  46  extends outside a proximal end  50  of the cannula shaft  40  when the trocar  42  is housed within the cannula  32 . 
     The cannula handle  38  includes grasping bars  52  and a cutout  54  formed in a top of the handle  38  for receipt and capturing of the trocar cap  44  of the trocar  42  when the trocar  42  is coupled with the cannula  32 . The cutout  54  includes at least one horizontally-oriented channel  56  formed in a sidewall  58  of the cutout  54  for receipt of a tab  60  horizontally extending from the trocar cap  44 . A user (who is commonly a surgeon or interventional pain physician) may position the trocar shaft  46  in the cannula lumen and then rotate the trocar cap  44  to guide the tab  60  into the channel  56 . The trocar  42  will then not be easily dislodged or moved with respect to the cannula  32  until the user reverses rotation of the trocar cap  44  to expose the tab  60  from the channel  56 . In embodiments, the cutout  54  may include opposing channels formed in opposing sidewalls of the cutout to receive two tabs extending from the trocar. The cannula handle  38  further includes a ball detent assembly that will be discussed further below and that is part of the incremental drill adjuster  36 . 
     In some steps of the method of embodiments of the invention, the trocar  42  will not be housed within the cannula  32 , but it is still desirable that the cannula be capped. In such instances, the cannula  32  will include a cannula cap  62  that is separate from the trocar cap  44  attached to a distal end of the trocar  42 . However, the cannula cap  62  will be substantially the same as the trocar cap  44 , except that the cannula cap  62  will include an axial cylindrical chamber  64  (see  FIG. 8 ) therethrough to provide a passage for accessing the cannula lumen, as described below. Additionally, the cannula cap  62  may include an axial tab (not shown) similar to the tab  60  on the trocar cap  44  to assist with interfitting the cap  62  with the cannula handle  38  via a friction fit. 
     The drill  34  of embodiments of the invention is illustrated in  FIGS. 3-8  and comprises a drill handle  66  and a drill shaft  68  coupled to the drill handle  66  and extending therefrom. The drill shaft  68  is hollowed to present a drill lumen. A drill stylet  70  having a handle  72  and shaft  74  extending therefrom is configured to fit within the drill lumen, i.e., the hollowed drill shaft  68 . A proximal end  76  of the drill stylet shaft  74  is configured to extend outside a proximal end  78  of the drill shaft  68  when the drill stylet  70  is housed within the drill  34 , as discussed in more detail below. Similar to the cannula handle  38 , the drill handle  66  includes grasping bars  80  and a cutout  82  formed in a top of the handle for receipt and capturing of the drill stylet handle  72  when the drill stylet  70  is coupled with the drill  34 . However, the drill handle cutout  82  is shaped differently than the cutout  54  on the cannula handle  38 . 
     In particular, the drill handle cutout  82  includes a seat  84 , sidewalls  86  extending distally from the seat  84 , and a notch  88  extending proximally from the seat  84 . The sidewalls  86  are complementally shaped to fit and receive the drill stylet handle  72 . Referring to  FIGS. 3 and 7 , the drill stylet handle  72  has a generally horizontally oriented shelf  90  and sidewalls  92  extending from the shelf  90 . Two tabs  94  extend horizontally from the shelf  90  on opposing front and rear sides of the shelf  90 . The sidewalls  92  are angled or otherwise shaped to be received within the cutout  54  formed in the drill handle  66 , such that the sidewalls  92  of the drill stylet handle  72  closely match the angle and shape of the sidewalls  58  of the drill handle cutout  54 . 
     To position the drill stylet  70  in the drill  34 , the user rotates the drill stylet  70 , such that a width of the stylet handle  72  is non-parallel to a width of the drill handle  66 . The user then inserts the drill stylet shaft  74  within the drill lumen. Once inserted, the user can rotate the drill stylet handle  72  to a position where the drill stylet handle width is generally parallel to the drill handle width, as best shown in  FIG. 7 . Upon rotation, the sidewalls  86  of the drill stylet handle  72  will closely match with the sidewalls  58  of the drill handle cutout  54 , as shown in  FIG. 7 . Moreover, the two tabs  94  extending from the drill stylet shelf  90  will overlap a portion of the drill handle  66  to prevent removal or dislodgement of the drill stylet  70  from the drill  34 , referred to as a locked position of the drill stylet  70 . In embodiments, upon rotation of the drill stylet handle  72  relative to the drill handle  66  to have the widths of the drill stylet handle and drill handle be substantially parallel, the tabs  94  may slightly catch to provide a further frictional securement. In this position, the shelf  90  of the drill stylet handle  72  sits atop the seat  84  of the drill handle  66 , as shown in  FIG. 7 . To remove the drill stylet  70  from the drill  34 , the user reverses rotation of the drill stylet handle  72 , such that the drill stylet handle width is non-parallel to the drill handle width. The user can then remove the drill stylet shaft  74  from the drill lumen. 
     When the drill stylet handle  72  is seated within the cutout  54  of the drill handle  66 , the drill stylet handle  72  does not fill the notch  88  that extends proximally from the seat  84 . That is, the notch  88  still presents an open cavity  96 , as best seen in  FIG. 7 . The purpose of the notch  88  is to allow the drill stylet shaft  74  to be advanced farther within the drill lumen. In particular, if the user reverses rotation of the drill stylet handle  72 , such that the drill stylet handle is non-parallel to the drill handle  66 , and the user continues reversal of rotation until the drill stylet handle  72  is approximately perpendicular to the drill handle  66 , the user can then set a portion of the shelf  90  of the drill stylet handle  72  within the notch  88 , as shown in  FIG. 5 . This is accomplished by the front to rear depth of the drill stylet handle  72  being less than the transverse width of the notch  88 . When the drill stylet shelf  90  is fit within the notch  88 , this in turn extends the proximal end  78  of the drill stylet shaft  74  outside of the proximal end  78  of the drill shaft  68  by an axial length of the notch  88 . In embodiments of the invention, the axial length of the notch (i.e., the length of the notch along a vertical axis) is approximately 0.5-5 mm, approximately 1-4 mm, approximately 2-3.5 mm, or approximately 3 mm. As discussed below in the method of embodiments of the invention, the user may desire to extend the drill stylet shaft  74  outside of the proximal end  78  of the drill shaft  68  to test whether the user has accessed the epidural space. 
     The drill shaft  68  is best illustrated in  FIG. 6  and presents the proximal end  78  and a distal end  98 , a drill bit segment  100  (also referred to herein as a “drill bit”) at the proximal end  78 , a straight-sided segment  102 , a detent segment  104 , and a shank segment  106  at the distal end  98 . The segments  100 , 102 , 104 , 106  are integral to each other, such that the drill shaft  68  is formed of a rigid, biocompatible material, such as steel, titanium, etc. The drill bit segment  100  includes a plurality of flutes  108  that assist in drilling into lamina of the patient&#39;s spinal column  22 . Upon rotation of the drill shaft  68 , as described in more detail below, the flutes  108  serve to create an access point into the spinal column  22 . The straight-sided segment  102  provides a length for the drill shaft  68 , such that the straight-sided segment  102  may be different lengths depending on the use of the drill  34  or preferences of a user of the drill. The detent segment  104  is described in more detail immediately below. The shank segment  106 , or a portion of a length of the shank segment, is mounted within the drill handle  66 . 
     The detent segment  104  is a component of the incremental drill adjuster  36 . The detent segment  104  provides a body  110  that is generally cylindrical along its length, except that a plurality of adjacent detents  112  or grooves is formed along at least a portion of a length of the detent segment  104 . In particular, the plurality of adjacent detents  112  is formed on one side of the generally cylindrical detent segment body  110 . The detents  112  are arranged side-by-side and are spaced approximately 0.1-0.8 mm apart, approximately 0.2-0.5 mm apart, or approximately 0.25 mm apart. That is, a length of a single detent  112  from a proximal end of the detent to a distal end of the detent is 0.1-0.8 mm, approximately 0.2-0.5 mm, or approximately 0.25 mm. The length of the detent segment  104  at the area comprising the detents generally forms a longitudinal channel in the detent segment body  110 , and the detents are formed in the longitudinal channel. The detents  112  are formed from slightly projecting walls  114 , as best illustrated in  FIG. 6 . Each pair of adjacent walls  114  extends from the detent segment body  110  to form a detent  112  therebetween, and each detent  112  presents a trough for receipt of a portion of a ball of the ball detent assembly discussed in more detail below. 
     As noted above, the detents  112  are formed in the longitudinal channel. Extending outside the channel and circumscribing the detent segment body  110  is a plurality of flutes  116 , with each flute  116  generally corresponding and aligning with a formed detent  112 . Each flute  116  presents a flute wall  118  that extends from the detent segment body  110 . As discussed in more detail below, as the drill  34  is rotated during insertion in the lamina, the user of the drill may apply enough force to dislodge the ball from a particular detent  112 ; in response to rotation of the drill handle  66 , guide the ball along a flute  116  adjacent to the detent  112  in which the ball was just located; and set the ball in one of the other detents  112 . 
     As shown in  FIGS. 7 and 8 , the drill shaft  68  is sized and configured to fit within the cannula cap  62 , through the cannula handle  38 , and through the cannula lumen. Thus, the drill stylet  70  is housed within the drill lumen, and the drill shaft  68  is housed within the cannula lumen. Each of these components collectively operates together, as described in more detail below. 
     Returning to the cannula handle  38 , the incremental drill adjuster  36  will now be described. The adjuster  36  allows for adjusting the drill  34  forward a set amount and in discrete movements so that the user is able to control proximal movement of the drill  34  and by the set amount. The incremental drill adjuster  36  comprises a ball detent assembly  120  and the detent segment  104 . The ball detent assembly  120  includes a ball  122  and a spring  124  that loads the ball  122  in each detent  112 . The detent segment  104 , which was described above, includes the plurality of adjacent detents  112  formed in the detent segment of the drill shaft and the corresponding flutes  116 . The ball detent assembly  120  is positioned in the cannula handle  38 , as best shown in  FIG. 8 . A side of the cannula handle  38  is hollowed to provide a chamber  126  to receive the ball  122  and spring  124 . A cap  128  is fitted onto the cannula handle  38  to close off the chamber  126  once the ball  122  and spring  124  are position in the chamber  126 . In embodiments, an end of the spring  124  may be secured to an inside of the cap, as shown in  FIG. 8 . In alternative embodiments, the ball  122  and spring  124  may be formed in the cannula cap  62  or one of the ball and spring may be formed in the cannula cap  62 . Therefore, it is not intended as limiting that a portion of the detent assembly  120  is described above as formed in the cannula handle  38 . 
     The ball  122  is spring-loaded, in that application of a force or pressure against the ball will compress or retract the spring  124  within the chamber  126 . Upon the spring  124  returning to its fully extended position within the chamber  128 , as shown in  FIG. 8 , the spring  124  seats a portion of the ball  122  in one of the detents  112  described above. To actuate the drill  34  forward, the user will apply sufficient force or pressure against the drill handle  66  to overcome the force of the spring  124  and push the ball  122  into the chamber  126 . Due to the ball  122  being spring-loaded, the user will be able to intuitively feel the force of the spring  124  pushing the ball forward into the adjacent detent. 
     To actuate proximal movement of the drill  34  (i.e., advance the drill into the lamina or other bone), the user first locates the drill stylet  70  within the drill handle  66  and in the locked position noted above. The locked position is shown in  FIG. 7  and occurs when the shelf  90  of the drill stylet handle  72  sits atop the seat  84  of the drill handle  66 . The drill shaft  68  is then positioned through the cannula cap  62  and into the cannula lumen, as shown in  FIGS. 7 and 8 . The user then inserts the drill shaft  68  through the cannula lumen and to the desired location and then releases any rotational force applied to the drill handle  66 . The release of the rotational force will seat the ball  122  into one of the detents  112 , as shown in  FIG. 8 . The user can then place the proximal end  78  of the drill shaft  68  proximate the desired location on the patient, e.g., proximate the lamina. The user will then rotate the drill handle  66  to begin drilling into the lamina. In embodiments of the invention, every 360 degree rotation of the drill handle  66  will advance the drill bit approximately 1 mm, although the drill assembly  26  can be sized to advance the drill shaft  68  less or more upon a single 360 degree rotation. At the initial stage of drilling, the user will likely be applying significant rotational force to advance the drill shaft  68  through the lamina. However, upon drilling through the lamina, not as much force is required to advance the drill shaft. At this stage, the user will take advantage of the incremental drill adjuster  36  to advance the drill shaft  68  in set amounts. In particular, the user may choose to advance the drill shaft  68  by only one detent length, such that the drill shaft  68  is advancing in relatively small but discrete amounts. This is desirable if the user is attempting to access the epidural space but without impacting the spinal cord, which is dangerous and painful for the patient. If in embodiments the drill shaft  68  advances approximately 1 mm for every 360 degree rotation, then approximately every quarter-turn or every approximately 90 degrees will seat the ball  122  in the next adjacent detent  112  and advance the drill shaft  68  by approximately 0.25 mm. The user can then incrementally adjust the drill  34  to obtain a precise drilling advancement into the access point. 
     The drill  34  described herein is for use in inserting the stimulators  10 . However, it should be appreciated that the drill  34  of embodiments of the invention could be used for other medical procedures and for drilling through bone on other areas of a patient (both human and animal). 
     In some instances the spinal column  22  can be accessed without needing to drill through the lamina. For example, in the lumbar region  18  of the patient, there is more room between adjacent lamina, which allows more room for the user to maneuver between the lamina to establish an access point within the spinal column. In this instance, the user need only penetrate soft tissue in the back to create the access point. However, in some instances in the lumbar region  18 , the patient may have arthritis or other issues that require drilling through the lamina. 
     In the instances where only soft tissue need be penetrated and the drill  34  is not required, embodiments of the invention use a needle  130  and needle stylet  132 , as illustrated in  FIG. 9 . The needle  130  presents a small handle  134  and a hollowed needle shaft  136  extending therefrom and presenting a needle lumen. The needle handle  134  has a generally cylindrical, axial opening (not shown) therethrough for the needle stylet  132 . The needle stylet  132  also includes a handle  138  and a needle stylet shaft  140 , although the needle stylet shaft  140  is not hollowed to present a lumen. A proximal end  142  of the needle stylet shaft  140  is pointed to assist in penetrating soft tissue. In operation, the needle stylet shaft  140  is fed through the opening in the needle handle  134  and through the needle lumen, and in embodiments, the pointed proximal end  142  of the needle stylet shaft  136  extends outside a proximal end  144  of the needle shaft  136 . 
     Turning now to  FIG. 10 , the guide wire assembly  28  of embodiments of the invention comprises an elongated guide wire  146 , a wound-wire sleeve  148  surrounding the guide wire  146 , and a magnet  150  coupled to a proximal end  152  of the guide wire assembly  28 . The elongated guide wire  146  is a long, thin section of wire that in embodiments is approximately 0.1-1.0 mm in diameter, approximately 0.2-0.8 mm in diameter, or approximately 0.3 mm in diameter. The wire  146  is flexible, such that it can be bent approximately 180 degrees in any direction. A length of the wire  146  is dependent on an axial length of the patient&#39;s spinal column  22 , such that the length of the wire should be long enough to extend axially through the patient&#39;s spinal column  22  from the lumbar region  18  and to the thoracic region  20  (or vice-versa) and with a working section (discussed below) extending from each region. Given the length of the guide wire  146 , the drawings illustrate the guide wire length in fragment, such as shown in  FIG. 10 . 
     The wound-wire guide wire sleeve  148 , as shown in  FIG. 10 , substantially covers the guide wire  146 . The sleeve  148  is formed of wire that is tightly wound to present a lumen in which the guide wire  146  is inserted. The sleeve  148  provides rigidity to the guide wire assembly  28  that is helpful during insertion of the guide wire assembly  28  into the spinal column  22 . However, the combined guide wire  146  and sleeve  148  are still flexible enough to be bent up to 180 degrees. The sleeve  148  is sized and configured to be easily slidable along the length of the guide wire  146 , so that the user can easily insert and remove the guide wire  146  into the sleeve lumen. The combined guide wire  146  and sleeve  148  are also sized and configured to easily slide within the needle lumen, as shown in  FIG. 11 , the guide wire receiver, as shown in  FIG. 17 , or an angiocath, as shown in  FIG. 13  and discussed in more detail below. 
     The guide wire assembly  28  further includes the magnet  150  coupled to the proximal end  152  of the guide wire assembly  28  and, in particular, the guide wire sleeve  148  (as opposed to the guide wire  146 ), as best illustrated in  FIG. 10 . The magnet  150  may be coupled to the end of the sleeve  148  via any method that secures the magnet  150  and prevents it from becoming dislodged from the end of the sleeve  148 . An exemplary securement method is an adhesive applied to the sleeve  148  and/or the magnet  150 . In embodiments, the magnet  150  may present a hollowed chamber (not shown) at one end so that the end of the sleeve  148  may be fitted within the hollowed chamber of the magnet. In embodiments, the magnet is approximately 1-3 mm in length or approximately 2 mm in length. The magnet  150  provides sufficient magnetic attraction to a magnet on an end of an angiocath (discussed below) to draw the two magnets together when the guide wire assembly  28  and angiocath are inserted into the epidural space. 
     Some steps of the method of embodiments of the invention may use a combined guide wire  146  and wound-wire sleeve  148  surrounding the guide wire  146 , but in such steps, the combination guide wire  146  and sleeve  148  does not include a magnet  150 , or, at the least, a magnet is required. That is, in some steps, a combination guide wire  146  and sleeve  148  can be used that does not include a magnet. In some embodiments of the invention, a kit that is provided with the components of the invention includes a combination guide wire  146  and sleeve  148  that does not include a magnet and a combination guide wire  146  and sleeve  148  that does include a magnet  150 . But, in other embodiments of the invention, the provided kit includes two combination guide wires  146  and sleeves  148 , each with a magnet. Even though the magnet is not required for one of the steps, as described below, two combination guide wires and sleeves with a magnet may still be provided for ease of manufacturing and not having to source two different components. In yet further embodiments, two combination guide wires and sleeves with no magnets are provided as a component of the kit. 
     Turning now to  FIGS. 13, 16   a - e ,  17 , and  18 , the guide wire receiver  30  will be described. The guide wire receiver  30  is inserted into the epidural space at the lumbar region  18 . The guide wire assembly  28  is inserted into the epidural space at the thoracic region  20 . In general but discussed in more detail below, the user feeds the guide wire assembly  28  through the spinal column  22  and to the guide wire receiver  30 . The receiver  30  is then sized and configured to easily catch or receive the guide wire assembly  28  so that the guide wire assembly  28  can be pulled through the access point at the lumbar region  18  of the patient&#39;s spine. 
     Referring to  FIG. 13 , the guide wire receiver  30  broadly comprises a handle  154 , a semi-cylindrical body  156  extending from the handle  154 , and a receiving section  158 . The handle  154  is hollowed to present a handle lumen that connects with a guide wire receiver lumen through the body  156 . A distal end  160  of the body  156  is completely closed about the cylindrical body; however, a majority of a length of the body  156  is open to present a semi-cylindrical body section  162 . As such, the guide wire receiver lumen at the semi-cylindrical body section  162  presents an open lumen. The receiving section  158  is integrally formed with and extends from the semi-cylindrical body section  162 . The receiving section  158  is at a proximal end  164  of the guide wire receiver  30 . The semi-cylindrical body section  162  widens at the receiving section  158  to present a scoop  166  comprising the receiving section and for receipt of the magnet  150  on the end of the guide wire assembly  28 , as shown in  FIG. 18 . 
     In more detail, the receiving section  158  of the guide wire receiver  30 , and namely, the scoop  166 , is flexible and configured to be rolled from an unfolded condition to a folded condition, as illustrated in  FIGS. 16 a -16 e   . The scoop  166  extends from the distal end  160  of the semi-cylindrical body section  162  to present sidewalls  168  and a proximal-most end  170 . The sidewalls  168  of the scoop  166  are angled outwards as the proximal-most end  170  of the scoop  166  is approached, such that the proximal-most end  170  of the scoop  166  is wider than the semi-cylindrical body section  162  of the guide wire receiver  30 . In the scoop&#39;s fully unfolded condition, illustrated in  FIG. 16 a   , the scoop&#39;s sidewalls  168  are generally raised as the sidewalls  168  extend from the semi-cylindrical body section  162  of the guide wire receiver  30 . However, as the sidewalls  168  widen as the proximal-most end  170  of the scoop  166  is approached, the sidewalls begin to flatten out, as illustrated in  FIG. 16 e   . As can be seen in  FIG. 16 a   , the sidewalls  168  of the scoop  166  are not completely flat, however, even in the fully unfolded condition, so as to present a flared proximal end. 
     The scoop  166  is flexible and especially designed to be “rolled up.” That is, the sidewalls  168  of the scoop  166  may be curved upwards from the fully unfolded position, as shown in  FIGS. 16 a  and 16 e   , to a fully-folded condition, as shown in  FIG. 16 d   . In the fully-folded condition, proximal ends of the sidewalls  168  of the scoop  166  are almost touching (see  FIG. 16 d   ), are touching (not shown), or are overlapping (not shown). The scoop  166  is thus foldable, and this foldable feature serves to capture the magnet  150  of the guide wire assembly  28  upon the magnet  150  being received in the unfolded scoop  166 . In other instances, the scoop  166  may not need to be either fully folded or full unfolded, and in such instances, the scoop may be folded to intermediate positions, as shown in  FIGS. 16 b  and 16 c   . The scoop  166  thus provides sufficient flexibility to be rolled from the unfolded to the fully-folded condition but also enough rigidity to hold a particular folded incremental position during use. Use of the guide wire receiver  30  will be described in more detail below. 
     As described below and as shown in  FIG. 17 , the guide wire receiver  30  is fed through a lumen of an introducer  172  or epiducer. During insertion, the scoop  166  is operable to roll to the fully-folded condition so that it can be inserted into the introducer lumen. To insert the guide wire receiver  30  into the introducer lumen, the user simply places the scoop  166  (which is presently in its fully-unfolded condition) against a distal end  174  of the introducer  172  and begins pushing the guide wire receiver  30  through the introducer lumen. When the scoop  166  is not inserted in a lumen, it is in a rest or natural state of the fully unfolded position of  FIG. 16 a   . However, upon the user beginning to insert the scoop  166  into the lumen, the scoop will begin to fold to the fully-folded position of  FIG. 16 d    for placement within the lumen. A length of the guide wire receiver  30  is longer than a length of the introducer  172 , such that the scoop  166  extends beyond a proximal end  176  of the introducer, as shown in  FIG. 17 . 
     The system  24  for securing spinal cord stimulators  10  also includes various other components. In particular and referring to  FIGS. 12, 14, 15, and 19-21 , the system  24  further comprises the introducer  172  (or epiducer), an introducer stylet  178 , a first angiocath  180 , a second angiocath  182  having a magnet  184  at one end, at least one monofilament  186 , and a connector  188  for connecting the monofilament  186  to the lead  12  of the percutaneous stimulators  10 . 
     The introducer  172  of embodiments of the invention may also be what is known in the art as an epiducer. Both the introducer  172  and epiducer include a handle  190  and a hollowed shaft  192  extending from the handle  190  and presenting a lumen. As is known in the art, an introducer typically has a cylindrical shaped shaft, whereas an epiducer has an oval or oblong shaped shaft when viewed in horizontal cross section. As discussed herein, the term “introducer” is defined to include both cylindrically shaped and oval or oblong shaped shafts, and as such, the term “introducer” is intended to encompass both the typical introducer and epiducer known in the art. Although not shown in the drawings, the introducer handle  190  is hollowed so that the introducer lumen and hollowed introducer handle can receive another component therethrough, as shown in  FIG. 17 . 
     As illustrated in  FIG. 12 , the introducer stylet  178  is configured to be inserted into the introducer lumen. The introducer stylet  178  comprises a handle  194 , a luer  196  for removably coupling the introducer stylet  178  with the introducer  172 , and a hollowed introducer stylet shaft  198  that includes a taper  200  at a proximal end. The introducer stylet shaft  198  extends from the handle  194  and through the luer  196 , and because the shaft is hollowed, the introducer stylet has a lumen. The shaft  198 , and specifically the taper  200 , is slightly flexible to provide some flexing upon application of pressure. A length of the introducer stylet shaft  198  is longer than a length of the introducer shaft  192 , such that when the introducer stylet  178  is housed within the introducer lumen, the taper  200  extends out from the proximal end of the introducer  172 . The luer  196  serves to couple the introducer stylet  178  with the introducer  172  by fitting the luer  196  over a portion of a distal end of the introducer  172  and rotating the luer  196  to obtain a friction fit. 
     The system  24  of embodiments employs at least two and potentially additional angiocaths. In embodiments, the first angiocath  180 , illustrated in  FIG. 14 , is a conventional angiocath having a handle  202  and a shaft  204  extending therefrom. The shaft  204  is generally flexible to allow an approximately 5-45 degree radius of movement about an axial length of the shaft. In the first angiocath  180  shown in  FIG. 14 , a proximal end  206  of the angiocath is substantially straight. However, the system  24  of embodiments of the invention contemplates including a plurality of angiocaths having proximal ends with various curvatures, such that the proximal end  206  is angled at a particular degree. Exemplary first angiocaths  180  include proximal ends  206  angled at 0 degrees (i.e., a straight proximal end), 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, and 30 degrees. The system may comprise a kit that includes some or all of the plurality of first angiocaths. 
     The second angiocath  182 , which is illustrated in  FIG. 19 , is substantially the same as the first angiocath (like reference numerals are used to indicate like structure), except that the second angiocath  182  includes the magnet  184  coupled to the proximal end  206  of the angiocath shaft  204 . The magnet  184  may be secured to the proximal end  206  via adhesive or other suitable securement method. The magnet  184  on the second angiocath  182  is configured to be attracted to the magnet  150  on the guide wire assembly  28 , as discussed above. As discussed in more detail below, during the method of stabilizing the spinal cord stimulators  10  in the patient, the magnet  184  on the second angiocath  182  is positioned proximate the magnet  150  on the guide wire assembly  28  so that the magnets are magnetically attracted to each other to removably couple the guide wire assembly to the second angiocath to allow for pulling of the guide wire assembly through the epidural space. 
     Similar to the first angiocath  180 , the system  24  may also include a plurality of second angiocaths  182 , with each second angiocath having a proximal end with a different radius of curvature. In particular, the proximal ends of each of the second angiocaths may be angled at 0 degrees (i.e., a straight proximal end), 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, and 30 degrees. The system  24  may comprise a kit that includes some or all of the plurality of second angiocaths. The purpose of the angled proximal ends will be discussed in more detail below. 
     Referring now to  FIG. 20 , the monofilament  186  is shown coupled to the lead  12  of the spinal cord stimulators  10 . The monofilament  186  is a single or multiple line of thin wire that is flexible and can be rolled or coiled upon itself, as shown in  FIG. 20 . However, the monofilament  186  also has enough rigidity to be guided into location and manipulated within the epidural space. In embodiments, the monofilament  186  is thinner in diameter than a diameter of the guide wire  146 . The monofilament  186  is biocompatible, and in embodiments, the monofilament  186  is formed of carbothane. The monofilament  186  is of a length that can extend the length of the patient&#39;s back and provide additional extraneous length at both the lumbar and thoracic regions  18 , 20 . In embodiments, a plurality of monofilaments  186  may be provided with the system  24  if multiple leads  12  are also used. 
     The connector  188  is also shown in  FIG. 20  and is, in embodiments, a relatively small piece of carbothane tubing that is configured to couple the monofilament  186  to the percutaneous lead  12 . In embodiments, the connector  188  is a cylindrical section of tubing that can receive an end of the monofilament  186  in one end of the connector  188 , and an end of the lead  12  in the other end of the connector  188 . The respective ends of the monofilament and lead are operable to be friction fit within the connector. The user can apply adhesive or another permanent coupling solution to securely couple the monofilament with the connector and the lead with the connector. In embodiments, the connector  188  is biocompatible, as it will be permanently implanted in the patient&#39;s epidural space, as discussed in more detail below. 
     The method of embodiments of the invention will now be described. The method comprises steps for using the system  24  of embodiments to secure and stabilize the percutaneous spinal cord stimulators  10  in the patient&#39;s spinal column  22 . The steps of the method need not be performed in the order presented below, unless expressly stated otherwise. Additionally, it should be appreciated that some steps may be combined into a single step, and some steps may be skipped altogether. Due to the nature of performing an invasive surgery on a patient, the user of the system may decide during the surgery to alter the performed steps described below. 
     To begin, the user (who is commonly a surgeon or other physician trained in spinal surgery and who will be referred to below as a surgeon) prepares the lumbar region  18  of the patient and creates a first access point. As noted above, the lumbar region  18  is at the tail of the patient&#39;s spine near the patient&#39;s buttocks. The surgeon will evaluate whether the drill assembly  26  is needed to access the epidural space through the patient&#39;s lamina. As noted above, in some patients the space between vertebrae is small, such as may be due to arthritis, which requires the surgeon to access the epidural space via the lamina. Because the lamina is bone, the drill assembly  26  of embodiments of the invention is required. However, for other patients, the surgeon may be able to access the epidural space through the soft tissue between adjacent lamina. In this instance, only the needle  130  and needle stylet  132  combination of embodiments of the invention is needed. 
     If the drill assembly  26  is needed to access the epidural space, the surgeon will locate the cannula  32  and trocar  42  combination on the lamina. The trocar  42  is then removed from the cannula  32 , leaving only the cannula  32 . The drill  34  and drill stylet  70  combination is then inserted into the cannula  32 . To initiate drilling through the lamina, the surgeon will apply an appropriate rotational force to the drill handle  66  to rotate the drill handle. As discussed above, an approximate 360 degree rotation of the drill handle  66  will effect an approximate 1 mm advanced of the drill shaft  68  through the lamina. As can be appreciated, drilling through the bony lamina will require an appropriate force applied to the drill handle  66  from the surgeon as compared to advancing the drill shaft  68  through soft tissue, for example, or incrementally advancing the drill shaft once the epidural space is reached. Once the surgeon successfully drills through the lamina, the surgeon will then take advantage of the incremental drill adjuster  36  to advance the drill shaft  68  in set amounts, as discussed above. Once the lamina, or most of the lamina, is penetrated, the epidural space is reached to create a first access point. The surgeon must be careful to fully access the epidural space and provide a clean and open access point but also not advance the drill shaft  68  so far into the epidural space as to touch the spinal cord. The incremental drill adjuster  36  allows for this fine precision once the majority of the lamina is drilled through. The surgeon will rotate the drill handle  66  to advance the ball  122  to the next adjacent detent  112 , as discussed above. Advancement by one detent length corresponds to approximately a one-quarter turn of the handle and 0.25 mm drill shaft advancement. The surgeon is normally performing the operation under X-ray so that the surgeon can see where the drill bit segment  100  is in relation to the lamina and when the drill bit segment  100  penetrates the lamina and enters the epidural space. Once the lamina is fully penetrated, the surgeon uses a blunt probe (not shown) to insure a clean and fully-open access point to the epidural space. 
     In embodiments of the invention, the surgeon may alternatively use the drill stylet  70  to insure that the epidural space is reached. As discussed above, the drill stylet  70  is inserted into the drill lumen. The drill stylet  70  and drill handle  66  are configured to allow the drill stylet  70  to be housed within the drill lumen in two positions. A first position, shown in  FIG. 7 , is where the drill stylet shelf  90  is seated on the drill handle seat  84 , such that the open cavity  96  of the notch  88  notch is exposed. A second position is shown in  FIG. 5  and is where the drill stylet  70  is rotated 90 degrees (from the position shown in  FIG. 7 ), such that a portion of the drill stylet handle  72  is seated within the notch  88 . In this position, the proximal end of the stylet  76  extends outside of the proximal end of the drill shaft  78  (i.e., outside a proximal end of the drill bit segment  100 ), as also shown in  FIG. 5 . Moving the drill stylet  70  to the second position with respect to the drill  34  allows the surgeon to insure that the epidural space is identified and accessed without touching the spinal cord, which as noted above, is dangerous and painful for the patient. Due to a length of the notch  88  in the drill handle  66 , the proximal end  76  of the drill stylet  70  is allowed to advance outside the proximal end  78  of the drill shaft  68  by approximately the length of the notch  88 . This length is enough for the surgeon to identify under X-ray that the epidural space is accessed, but not enough length to touch the spinal cord. 
     Once the surgeon identifies the epidural space, the surgeon then removes the drill  34  from the cannula  32 , leaving only the cannula  32 . The surgeon will then feed the guide wire assembly  28  through the cannula  32  and through first access point. The surgeon removes the cannula  32  distally, leaving only the guide wire assembly  28  penetrating the first access point. The surgeon then insures that the introducer stylet  178  is housed within the introducer lumen. As shown in  FIG. 15 , the combination introducer  172  and introducer stylet  178  are then fed over the guide wire assembly  28  penetrating the first access point so that the introducer and introducer stylet penetrate through the first access point. The surgeon then removes the guide wire assembly  28  from the introducer  172  and introducer stylet  178  combination by pulling the guide wire assembly  28  distally through the introducer stylet lumen. The purpose of first placing the guide wire assembly  28  through the first access point prior to placement of the introducer  172  and introducer stylet  178  combination is to provide rigidity to the introducer  172  and introducer stylet  178  combination to prevent the introducer stylet tapered end  200  from touching or penetrating the spinal cord and to further provide a guide for insertion of the introducer and introducer stylet combination. 
     If the drill  34  is not needed to access the epidural space at the lumbar region  18 , such as may be the case if the surgeon can access the epidural space through soft tissue, then the surgeon may optionally only use the needle  130  and needle stylet  132  illustrated in  FIG. 9 . The surgeon inserts the stylet  132  through the needle lumen and then uses the needle  130  and stylet  132  combination to penetrate the soft tissue to create the first access point. The surgeon then removes the stylet  132  and inserts the guide wire assembly  28  through the needle lumen, as shown in  FIG. 11 . Once the guide wire assembly  28  is inserted through the first access point, the surgeon removes the needle  130 , leaving only the guide wire assembly  28 . The surgeon then performs the following steps, similar to if the drill  34  was used to create the first access point, as described above. In particular, the surgeon then insures that the introducer stylet  178  is housed within the introducer lumen. The combination introducer  172  and introducer stylet  178  are then fed over the guide wire assembly  28  penetrating the first access point so that the introducer and introducer stylet penetrate through the first access point, as shown in  FIG. 15 . The surgeon then removes the guide wire assembly  28  from the introducer  172  and introducer stylet  178  combination by pulling the guide wire assembly  28  distally through the introducer stylet lumen. The surgeon removes the introducer stylet  178 , leaving only the introducer  172  at the first access point. 
     The surgeon next creates a second access point at the patient&#39;s thoracic region  20 . As should be appreciated, the surgeon may first create an access point at the thoracic region and then create an access point at the lumbar region, or vice-versa. Reference to first and second access points is not intended to imply that one access point must be surgically be performed before another access point. 
     The surgeon will prepare the surgical area on the patient at approximately T4 or T5 in the thoracic region  20 . Once the surgeon identifies a preferred second access point, the surgeon inserts the combined cannula  32  and trocar  42  onto the lamina. Similar to the lumbar region  18  and creation of the first access point with the drill  34 , the surgeon removes the trocar  42  from the cannula  32  and inserts the drill  34  and the drill stylet  70  into the cannula lumen. The surgeon then advances the drill  34  through the lamina to create the second access point. In embodiments that set the drill at advancement of 1 mm based on a single 360 degree rotation of the drill handle  66 , the surgeon will normally advance the drill in 1 mm increments. Advancement of the drill is substantially similar to the steps described above for the lumbar region. Upon drilling through, or almost through, the lamina, the surgeon may choose to advance the drill in 0.25 mm increments using the incremental drill adjuster  36 , as described above. Once the epidural space is identified, the surgeon will then use a blunt probe (not shown) to test for the epidural space or use the drill stylet  70 , as described above for the lumbar region  18 . 
     After the surgeon creates the second access point at the thoracic region  20 , the surgeon removes the drill  34  and drill stylet  70  from the cannula lumen, leaving the cannula  32  on the lamina. At this next step, the surgeon inserts the guide wire assembly  28  through the cannula  32 , into the second access point, and into the epidural space at the thoracic region  20 . In some circumstances, the surgeon may have difficulty in inserting the guide wire assembly  28  through the cannula  32  and into the epidural space. In particular, the angle of insertion through the second access point and into the epidural space may not allow for easy insertion. In such circumstances, the surgeon may insert one of the plurality of first angiocaths  180  through the cannula lumen. As noted above, the system  24  of embodiments of the invention includes the plurality of first angiocaths  180 , with each angiocath having a proximal end with a different angle of curvature. Under X-ray, the surgeon will be able to view the required angle of curvature. Upon inserting the first angiocath  180  into the epidural space, the surgeon inserts the guide wire assembly  28  through the angiocath lumen, as shown in  FIG. 14  (note that for ease of illustration,  FIG. 14  does not illustrate the first angiocath  180  into the cannula lumen, as described above). The guide wire assembly  28  is inserted with the magnet  150  at the proximal end, so that the magnet  150  is inserted first through the first angiocath  180 . The first angiocath&#39;s proximal end then assists in positioning the guide wire assembly  28  into the epidural space and axially through the spinal column. The surgeon then uses the first angiocath  180  to direct the guide wire assembly  28  into the midline of the thoracic epidural space. Once the guide wire assembly  28  is in place, the surgeon removes the first angiocath  180 . 
     Returning to the lumbar region  18 , recall that the introducer  172  alone is positioned at the first access point. The guide wire assembly  28  has been removed from the introducer  172 . At this point, the surgeon inserts the guide wire receiver  30  through the introducer lumen and into the first access point. Operating under X-ray, the surgeon advances the guide wire assembly  28 , which is inserted through the second access point at the thoracic region  20 , towards the guide wire receiver  30  inserted through the first access point at the lumbar region  18 . The surgeon uses the guide wire receiver  30  to catch the guide wire assembly  28  being pushed from the thoracic end  20  and towards the lumbar end  18 , as shown in  FIG. 18 . The sidewalls  168  of the scoop  166  of the guide wire receiver  30  surround and hold the magnet  150  of the guide wire assembly  28  within the scoop  166  as the surgeon advances the guide wire assembly  28  into the semi-cylindrical body section  162  of the guide wire receiver  30 . 
     In some instances, the surgeon may have difficulty catching the guide wire assembly  28  with the scoop  166  alone. In such circumstances, the surgeon inserts one of the plurality of second angiocaths  182  through the guide wire receiver lumen, as shown in  FIG. 19 . Recall that the second angiocath  182  has the proximal end provided with the magnet  184 . When the proximal end of the second angiocath  182  extends outside the guide wire receiver lumen (e.g., when the magnet  184  is proximate the scoop  166 ), the magnet  184  on the second angiocath  182  is magnetically attracted to the magnet  150  on the guide wire assembly  28 . Upon the two magnets  150 , 184  magnetically coupling, the surgeon can pull the second angiocath  182  distally from the guide wire receiver  30  to position the proximal end of the guide wire assembly  28  within the scoop  166  and into the guide wire receiver lumen. Once the guide wire assembly  28  is captured within the guide wire receiver  30 , the surgeon pulls the guide wire receiver  30  distally from the introducer lumen to pull the guide wire assembly  28  distally through the first access point. The surgeon thus removes the guide wire receiver  30  from the introducer lumen, leaving only the introducer  172  fed over the guide wire assembly  28 . At this time, the guide wire assembly  28  extends through the patient&#39;s spinal column and both of the first and second access points. 
     Working at the lumbar region  18 , the surgeon next cuts the proximal end  152  of the guide wire assembly  28  external to the first access point proximal the magnet  150 . In essence, the surgeon cuts the magnet  150  off of the guide wire assembly&#39;s proximal end  152 . Due to the relatively small diameter of the guide wire assembly  28 , the surgeon can easily cut through the guide wire sleeve  148  and guide wire  146  with surgical scissors or wire cutters. Once the magnet  150  is cut off the guide wire assembly  28 , the guide wire  146  internal to the guide wire sleeve  148  is exposed. The surgeon removes the guide wire  146  from the sleeve  148  to leave only the guide wire sleeve  148  extending through the patient&#39;s spinal column. Note that in embodiments of the invention, a distal end of the guide wire assembly  28  is not closed, such that the guide wire  146  within the guide wire sleeve  148  is exposed. Therefore, the surgeon may remove the guide wire  146  from either the lumbar  18  or thoracic ends  20  of the patient&#39;s back. In alternative embodiments where the guide wire assembly  28  is closed at the distal end, the surgeon cuts the guide wire assembly proximate the distal end to expose the guide wire  146  within the sleeve  148 , as is done for the proximal end  152 , in the event the surgeon desires to remove the guide wire  146  from the sleeve  148  via the thoracic end  20 . 
     The surgeon then feeds the monofilament  186  through the guide wire sleeve  148  from the lumbar end  18  and to the thoracic end  20 . Once the monofilament  186  is fed through the guide wire sleeve  148 , the monofilament  186  extends through the patient&#39;s spinal column  22  and external both the first and second access points. The surgeon then removes the guide wire sleeve  148  from the patient&#39;s spinal column through either the first or second access point. The guide wire sleeve  148  provides a sufficient stiffness through the epidural space to allow the monofilament  186  to be positioned in the epidural space. At this time, the monofilament  186  is positioned through the first access point, through the epidural space of the patient&#39;s spinal column, and through the second access point at the thoracic region  20 . 
     The surgeon is now ready to insert the spinal cord stimulator  10  into the patient&#39;s epidural space. As discussed above, the stimulator  10  may have a plurality of leads  12  (otherwise known as an array of leads) that is one or more electrodes. Each lead  12  is attached to a lead wire  14  that is eventually coupled with the IPG  16 . To feed each lead  12  through the epidural space of the patient&#39;s spinal column  22 , the surgeon uses the connector  188  to connect the lead  12  with the monofilament  186 . In instances where more than one lead  12  is used, the surgeon may insert multiple monofilaments  186  through the epidural space, so that each lead  12  is individually coupled with a monofilament  186 . It should be appreciated that in embodiments of the invention, there is a one-to-one ratio of leads to monofilaments. It is common for the surgeon to place a plurality of leads through the epidural space, and therefore, embodiments of the invention contemplate positioning a plurality of monofilaments through the epidural space. Note that in alternative embodiments, one lead wire  14  may be connected to a plurality of leads  12 . 
     Working at the lumbar region  18 , the surgeon couples an end of each lead  12  of the stimulator  10  to the exposed end of the monofilament  186  using the connector  188 . As shown in  FIG. 20 , the end of the lead  12  is inserted through one end of the connector  188  and held via a friction fit, and the end of the monofilament  186  is inserted through the other end of the connector  188  and held via a friction fit. The surgeon may choose to permanently couple the connector  188  with the lead  12  of the stimulator  10  and the monofilament  186  by applying a small amount of adhesive to each end of the connector and the coupled lead/monofilament. Once the monofilament  186  is coupled with the lead  12  via the connector  188 , the surgeon then turns to the thoracic region  20 . The surgeon pulls the exposed monofilament  186  at the thoracic end  20  distally to pull the monofilament  186  through the epidural space. This in turn pulls the lead  12  connected to monofilament  186  through the epidural space. The surgeon is the able to position the lead  12  within the desired location of the spinal column  22  by pulling the monofilament  186  from the thoracic end  20 . 
     As noted above, there may be multiple leads with multiple wires, and therefore, multiple monofilaments. Once each monofilament is coupled to its respective lead, and each lead is positioned within the epidural space, the surgeon excises the skin at the lumbar region and removes the introducer  172  located at the first access point. The surgeon then applies a sylastic anchor (not shown) to secure the lead wire  14  at the patient&#39;s lumbar region. The surgeon prepares a pocket in the patient&#39;s lumbar region for the IPG  16 , connects the first access point and the pocket for the IPG with a tunneling instrument (not shown), pulls the lead wire  14  through the tunneling instrument, and connects the lead wire to the IPG. As discussed above, the IPG  16  controls application of voltage to the leads  12 , and the signal is sent through the lead wire  14 . 
     The surgeon then turns to the thoracic region  20  to secure the exposed monofilament  186 . Similar to the lead wire at the lumbar end  18 , the surgeon trims the monofilament  186  as needed. However, the surgeon leaves an exposed monofilament, referred to as a tension relief portion. The surgeon will use this exposed tension relief portion to move the lead  12  within the epidural space during the patient&#39;s ongoing use of the stimulator  10 . Prior to securing the tension relief portion within an excised portion of skin in the patient, the surgeon removes the cannula  32 . To secure the tension relief portion, the surgeon forms a loop or otherwise gathers the exposed tension relief portion. The surgeon excises the skin at the thoracic end and prepares a pocket for securing the exposed tension relief portion. The surgeon secures the tension relief portion using sylastic anchors (not shown). Thus, the lead is secured, via the monofilament, at the thoracic end of the patient. 
     In embodiments of the invention, the surgeon can move the lead(s) within the epidural space by gathering or releasing either or both of the lead wire(s)  14  connected to the leads  12  at the lumbar region  18  or the monofilament(s)  186  at the thoracic region  20 . Because each percutaneous lead  12  is coupled to its respective monofilament  186  at the thoracic end  20 , and the lead wire  14  is coupled to the lead  12  at the lumbar end  18 , the leads will not move axially within the epidural space once the lead wire and monofilament are secured with the anchors. However, the surgeon can move the lead within the epidural space as desired. 
     Although the invention has been described with reference to the embodiments illustrated in the attached drawing figures, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims. Having thus described various embodiments of the invention, what is claimed as new and desired to be protected by Letters Patent includes the following: