Abstract:
A detachable handle includes a handle body that is substantially tubular and defines a hollow center region extending at least a portion of a longitudinal length of the handle body. The handle body is configured and arranged to receive a portion of a stylet handle within the hollow center region and removably attach to the stylet handle. The handle body includes an external gripping surface extending at least a portion of an exterior surface of the handle body.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This Application is a Non-Provisional of Provisional (35 USC 119(e)) application 61/038,671 filed on Mar. 21, 2008, the disclosures of which are herein incorporated by reference in their entirety. 
     
    
     FIELD 
       [0002]    The present invention is directed to the area of implantable electrical stimulation systems and methods of making and using the systems. The present invention is also directed to detachable handles for implantable electrical stimulation systems, as well as methods of making and using the detachable handles. 
       BACKGROUND 
       [0003]    Implantable electrical stimulation systems have proven therapeutic in a variety of diseases and disorders. For example, spinal cord stimulation systems have been used as a therapeutic modality for the treatment of chronic pain syndromes. Deep brain stimulation has also been useful for treating refractory chronic pain syndromes and has been applied to treat movement disorders and epilepsy. Peripheral nerve stimulation has been used to treat chronic pain syndrome and incontinence, with a number of other applications under investigation. Functional electrical stimulation systems have been applied to restore some functionality to paralyzed extremities in spinal cord injury patients. Moreover, electrical stimulation systems can be implanted subcutaneously to stimulate subcutaneous tissue including subcutaneous nerves such as the occipital nerve. 
         [0004]    Stimulators have been developed to provide therapy for a variety of treatments. A stimulator can include a control module (with a pulse generator), one or more leads, and an array of stimulator electrodes on each lead. The stimulator electrodes are in contact with or near the nerves, muscles, or other tissue to be stimulated. The pulse generator in the control module generates electrical pulses that are delivered by the electrodes to body tissue. 
       BRIEF SUMMARY 
       [0005]    In one embodiment, a detachable handle includes a handle body that is substantially tubular and defines a hollow center region extending at least a portion of a longitudinal length of the handle body. The handle body is configured and arranged to receive a portion of a stylet handle within the hollow center region and removably attach to the stylet handle. The handle body includes an external gripping surface extending at least a portion of an exterior surface of the handle body. 
         [0006]    In another embodiment, an electrical-stimulation implantation system includes a lead having a proximal end and a central lumen, a stylet having a stylet handle and an insertion rod, and a detachable handle attachable to a portion of the stylet handle. The insertion rod is insertable into the central lumen of the lead. The detachable handle includes a handle body that is substantially tubular and defines a hollow center region extending at least a portion of a longitudinal length of the handle body. The handle body is configured and arranged to receive a portion of a stylet handle within the hollow center region and removably attach to the stylet handle. The handle body includes an external gripping surface extending at least a portion of an exterior surface of the handle body. 
         [0007]    In yet another embodiment, a method for implanting an electrical-stimulation system includes inserting an insertion rod of a stylet with a stylet handle into a central lumen of a lead with a proximal end, attaching a detachable handle to a portion of the stylet handle, and using the detachable handle to guide the lead and coupled stylet into a previously-created surgical incision. The detachable handle includes a handle body that is substantially tubular and defines a hollow center region extending at least a portion of a longitudinal length of the handle body. The handle body is configured and arranged to receive a portion of a stylet handle within the hollow center region and removably attach to the stylet handle. The handle body includes an external gripping surface extending at least a portion of an exterior surface of the handle body. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following drawings. In the drawings, like reference numerals refer to like parts throughout the various figures unless otherwise specified. 
           [0009]    For a better understanding of the present invention, reference will be made to the following Detailed Description, which is to be read in association with the accompanying drawings, wherein: 
           [0010]      FIG. 1  is a schematic view of one embodiment of an electrical stimulation system, according to the invention; 
           [0011]      FIG. 2  is a schematic view of another embodiment of an electrical stimulation system, according to the invention; 
           [0012]      FIG. 3A  is a schematic side view of one embodiment of a detachable handle for an electrical-stimulation implantation system, according to the invention; 
           [0013]      FIG. 3B  is a schematic perspective view of the embodiment of the detachable handle shown in  FIG. 3A , according to the invention; 
           [0014]      FIG. 3C  is a schematic longitudinal cross-sectional view of the embodiment of the detachable handle shown in  FIG. 3A , according to the invention; 
           [0015]      FIG. 4  is a schematic side view of one embodiment of an electrical-stimulation implantation system, according to the invention; 
           [0016]      FIG. 5  is a schematic side view of the embodiment of the electrical-stimulation implantation system shown in  FIG. 4  with an insertion rod inserted in a proximal end of a lead, according to the invention; 
           [0017]      FIG. 6A  is a schematic side view of the embodiment of the electrical-stimulation implantation system shown in  FIG. 4  with a stylet handle disposed in a detachable handle, according to the invention; 
           [0018]      FIG. 6B  is a schematic side view of the embodiment of the electrical-stimulation implantation system shown in  FIG. 4  with both a stylet handle and a proximal end of a lead disposed in a detachable handle, according to the invention; 
           [0019]      FIG. 7A  is a schematic longitudinal cross-sectional view of the embodiment of the detachable handle shown in  FIG. 3C  with a portion of a stylet handle disposed entirely in a hollow center region of the detachable handle, according to the invention. 
           [0020]      FIG. 7B  is a schematic longitudinal cross-sectional view of the embodiment of the detachable handle shown in  FIG. 3C  with a portion of a stylet handle disposed partially in a hollow center region of the detachable handle, according to the invention. 
           [0021]      FIG. 7C  is a schematic longitudinal cross-sectional view of the embodiment of the detachable handle shown in  FIG. 3C  with a portion of a stylet handle and a proximal end of a lead each disposed in a hollow center region of the detachable handle, according to the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    The present invention is directed to the area of implantable electrical stimulation systems and methods of making and using the systems. The present invention is also directed to detachable handles for implantable electrical stimulation systems, as well as methods of making and using the detachable handles. 
         [0023]    Suitable implantable electrical stimulation systems include, but are not limited to, an electrode lead with one or more electrodes disposed on a distal end of the lead and one or more terminals disposed on a proximal end of the lead. Electrode leads include, for example, percutaneous leads and paddle leads. Examples of electrical stimulation systems with electrode leads are found in, for example, U.S. Pat. Nos. 6,181,969; 6,516,227; 6,609,029; 6,609,032; and 6,741,892; and U.S. patent application Ser. Nos. 11/238,240; 11/319,291; 11/327,880; 11/375,638; 11/393,991; and 11/396,309, all of which are incorporated by reference. 
         [0024]      FIG. 1  illustrates schematically one embodiment of a stimulation system  100 . The stimulation system includes a control module (e.g., a stimulator or pulse generator)  102  and an array of electrodes  134  disposed at or near the distal end of a lead body  106  forming a percutaneous lead. The percutaneous lead may be isodiametric along the length of the percutaneous lead. The control module  102  typically includes an electronic subassembly  110  and optional power source  120  disposed in a sealed housing  114 . The control module  102  typically includes a port  144  into which the proximal end of the lead body  106  can be plugged to make an electrical connection via contacts (not shown in  FIG. 1 ) on the control module  102  and lead body  106 . In addition, one or more lead extensions (not shown) can be disposed between the lead and the control module  102  to extend the distance between the control module  102  and the lead body  106 . It will be understood that the stimulation system can include more, fewer, or different components and can have a variety of different configurations including those configurations disclosed in the stimulation system references cited herein. For example, as shown in  FIG. 2 , instead of an array of electrodes disposed at or near the distal end of a lead body  106 , a lead may include a paddle body  104 , and at least one lead body  106  coupling the control module to the paddle body. Collectively, the paddle body  104  and the lead body  106  form a paddle lead. The paddle body  104  typically includes an array of electrodes  134 . 
         [0025]    The stimulation system or components of the stimulation system, including one or more of the lead body  106  and the control module  102 , are typically implanted into the body. The stimulation system can be used for a variety of applications including, but not limited to, brain stimulation, neural stimulation, spinal cord stimulation, muscle stimulation, and the like. 
         [0026]    The electrodes  134  can be made using any conductive material. Examples of suitable materials include metals, alloys, conductive polymers, conductive carbon, and the like, as well as combinations thereof. The number of electrodes  134  in the array of electrodes  134  may vary. For example, there can be two, four, six, eight, ten, twelve, fourteen, sixteen, or more electrodes  134 . As will be recognized, other numbers of electrodes  134  may also be used. 
         [0027]    The electrodes of a lead are typically disposed in a non-conductive, biocompatible material including, for example, silicone, polyurethane, polyetheretherketone (PEEK), epoxy, and the like or combinations thereof. A lead may be formed in the desired shape by any process including, for example, molding (including injection molding), casting, and the like. The non-conductive material typically extends from the distal end of the lead to the proximal end. When a paddle body  104  is incorporated into a lead, the non-conductive, biocompatible material of the lead body  106  and paddle body  104  may be the same or different, and the lead body  106  and the paddle body  104  may be a unitary structure or can be formed as two separate structures that are permanently or detachably coupled together. 
         [0028]    Conductive contacts are typically disposed at the proximal end of a lead for connection to a corresponding conductive contact in the control module  102  (or to conductive contacts on a lead extension). Conductive wires extend from the conductive contacts to the electrodes  134 . Typically, one or more electrodes are electrically connected to a contact. In some embodiments, each contact is only connected to one electrode. The conductive wires may be embedded in the non-conductive material of the lead or can be disposed in one or more lumens extending along the lead. In some embodiments, there is an individual lumen for each conductive wire. In other embodiments, two or more conductive wires may extend through a lumen. There may also be one or more lumens that open at, or near, the distal end of the lead, for example, for infusion of drugs or medication into the site of implantation of the lead. 
         [0029]    Leads can be implanted into an implantee using a stylet that includes an insertion rod and a stylet handle. An insertion rod can be slid into the proximal end of a lumen of a lead and used to stiffen the lead in order to facilitate maneuvering of the lead within the implantee. Once an insertion rod is placed within a lead, a health care professional can insert the lead (with the insertion rod) into an incision in the implantee and use the stylet handle to guide the lead to a desired implantation site. Once the insertion rod and the lead are in the desired implantation site, the insertion rod can subsequently be removed from the lead and conductive contacts within the proximal end of the lead can be coupled to corresponding conductive contacts in the control module  102  to establish an electrical connection between the control module  102  and the electrodes  134  at the distal end of the lead. 
         [0030]    Implanting an electrical stimulation system can require a high degree of surgical skill. Such skill may be needed to use a stylet handle to safely and precisely maneuver a lead within an implantee to a desired implantation site. Unfortunately, stylet handles are often small and may not provide enough tactile feedback for at least some health care professionals. 
         [0031]      FIG. 3A  is a schematic side view of one embodiment of a detachable handle for an electrical-stimulation implantation system, according to the invention. A detachable handle  302  includes a handle body  304  with a first end  306  and a second end  308 . The handle body  304  further includes an external gripping surface  310  with a plurality of tactile features, such as tactile feature  312 , and an annular feature  314  between the first end  306  and the external gripping surface  310 . In the embodiment shown in  FIG. 3A , the tactile features are disposed along a longitudinal axis, across a portion of the external gripping surface  310 . In other embodiments, the tactile features are disposed along axes other than the longitudinal axis or disposed in multiple axes that either include or do not include the longitudinal axis. In yet other embodiments, the tactile features are of other shapes suitable for providing tactile feedback to a user gripping the external gripping surface  310 . In some embodiments, the handle body  304  is sized to accommodate a hand of a user, either customized for individual use or manufactured in one or more sizes designed to fit a wide selection of average-hand-sized users. 
         [0032]      FIG. 3B  is a schematic perspective view of the embodiment of the detachable handle shown in  FIG. 3A , according to the invention. The handle body  304  includes a hollow center region  316  that extends along a longitudinal axis of the handle body  304 . In some embodiments, the hollow center region  316  extends the entire longitudinal length of the handle body  304  while, in other embodiments, the hollow center region  316  extends only a portion of the handle body  304 . In  FIG. 3B , the hollow center region  316  is shown having a cross-sectional shape which is round. In other embodiments, the cross-sectional shape of the hollow center region  316  is a shape other than round. In various embodiments, the cross-sectional shape of the hollow center region  316  may be varied to accommodate the cross-sectional shapes of components received by the hollow center region  316 . In some embodiments, various portions of the hollow center region  316  have various different cross-sectional shapes and sizes when, for example, the hollow center region  316  is receiving two or more components with different cross-sectional shapes and/or sizes. 
         [0033]      FIG. 3C  is a schematic longitudinal cross-sectional view of the embodiment of the detachable handle shown in  FIG. 3A , according to the invention. In  FIG. 3C , the hollow center region  316  extends the entire longitudinal length of the handle body  304  and includes a first reduced-caliber region  318  at the first end  306  and a second reduced-caliber region  320  at the second end  308 . In alternate embodiments, the hollow center region  316  extends through only a portion of the handle body  304 . In other alternate embodiments, the first reduced-caliber region  318  is in proximity to the first end  306  and/or the second reduced-caliber region  320  is in proximity to the second end  308 . In some embodiments, there are more than two reduced-caliber regions while in other embodiments there is only one reduced caliber region. In various embodiments, the longitudinal length and the caliber of the reduced-caliber regions may vary. For example, in one embodiment the reduced-caliber regions of a handle body collectively comprise approximately half or less of the longitudinal length of the handle body, while in another embodiment the reduced-caliber regions of a handle body collectively comprise approximately one-third or less of the longitudinal length of the handle body. Additionally, in various embodiments, the shape of the reduced-caliber regions may have a cross-sectional shape that is not round. For example, in one embodiment the cross-sectional shape of a reduced-caliber region is oblong. In another embodiment the cross-sectional shape of a reduced-caliber region is rectangular. 
         [0034]    A detachable handle may be formed as a unitary structure or may be formed as two or more separate structures that are permanently or detachably coupled together. A detachable handle can be fabricated in a desired shape by any process, for example, molding, casting, and the like. In some embodiments, a detachable handle is disposed in a compliant material, such as silicone rubber, and the like, which can be used to create an interference fit with components received by a hollow center region, as discussed below, with reference to  FIGS. 7A-7C . 
         [0035]    A detachable handle can be used to facilitate maneuverability of a lead during implantation of an electrical stimulation system. In one embodiment, a stylet handle is disposed in a detachable handle. In another embodiment, both a stylet handle and a proximal end of a lead are disposed in a detachable handle. Accordingly, the embodiments described above, with relation to  FIGS. 3A-3C , may provide an advantage by incorporating a detachable handle, preferably with improved tactile feedback, and also may provide an advantage by making available the option to engage only a stylet handle or to engage both a stylet handle and a lead. 
         [0036]      FIG. 4  is a schematic side view of one embodiment of an electrical-stimulation implantation system, according to the invention. An electrical-stimulation implantation system includes a detachable handle  302 , a stylet  402 , and a lead  404 . The stylet  402  includes a stylet handle  406  and an insertion rod  408 . The lead  404  includes a proximal end  410  and one or more lumens  412  disposed in at least a portion of a longitudinal length of the lumen  412 . In  FIG. 4 , the insertion rod  408  of the stylet  402  is shown as an elongated rectangle. For clarity of illustration, in several subsequent figures the insertion rod  408  is shown as a line. Also for clarity of illustration, in several subsequent figures the lumen  412  is omitted. 
         [0037]    In various embodiments of the present intention, the cross-sectional shape of the stylet  402 , the insertion rod  408 , the stylet handle  406 , the lead  404 , and/or the lumen  412  of the lead  404  may be of many different shapes, including, circular, oblong, square, rectangular, triangular, or other suitable shape. In at least some embodiments, the cross-sectional shape of the stylet handle  406  and the proximal end  410  of the lead  404  match the cross-sectional shape of the hollow center region ( 316  in  FIG. 3B ) of the detachable handle ( 302  in  FIG. 3A ). Additionally, in at least some embodiments, the cross-sectional shape of the lumen  412  matches the cross-sectional shape of the insertion rod  408 . In  FIG. 4 , and in subsequent figures, the lead  404  is shown as a percutaneous lead. In various other embodiments, the lead  404  is a paddle lead ( 104  in  FIG. 2 ), or some other type of lead. 
         [0038]      FIG. 5  is a schematic side view of the embodiment of the electrical-stimulation implantation system shown in  FIG. 4  with an insertion rod inserted in a proximal end of a lead, according to the invention. The insertion rod  408  of the stylet  402  is partially inserted into the lumen (not shown in  FIG. 5 ) of the lead  404  and the stylet handle  406  is in proximity to the proximal end  410  of the lead  404 . The detachable handle  302  is attached to neither the stylet handle  406  nor the proximal end  410  of the lead  404 . 
         [0039]    In some embodiments, a stylet handle is disposed in a detachable handle while a corresponding lead is not.  FIG. 6A  is a schematic side view of the embodiment of the electrical-stimulation implantation system shown in  FIG. 4  with a stylet handle disposed in a detachable handle, according to the invention. In  FIG. 6A , the stylet  402  is disposed in the detachable handle  302 . Specifically, the stylet handle  406  is disposed in the hollow center region ( 316  in  FIG. 3B ) of the detachable handle  302 . In the embodiment shown in  FIG. 6A , a portion of the stylet handle  406  extends out of the second end  308  of the detachable handle  302 . In other embodiments, the stylet handle  406  does not extend out of the second end  308  of the detachable handle  302 . 
         [0040]    In other embodiments, both a stylet handle and a proximal end of a lead are disposed in a detachable handle.  FIG. 6B  is a schematic side view of the embodiment of the electrical-stimulation implantation system shown in  FIG. 4  with both a stylet handle and a proximal end of a lead disposed in a detachable handle, according to the invention. In  FIG. 6B , the stylet  402  and the lead  404  are disposed in the detachable handle  302 . Specifically, the stylet handle  406  and the proximal end  410  of the lead  404  are disposed in the hollow center region ( 316  in  FIG. 3B ) of the detachable handle  302 . In the embodiment shown in  FIG. 6B , a portion of the stylet handle  406  extends out of the second end ( 308  in  FIG. 3A ) of the detachable handle  302 . In other embodiments, the stylet handle  406  does not extend out of the second end ( 308  in  FIG. 3A ) of the detachable handle  302 . 
         [0041]    Once a desired portion of a stylet handle is disposed in a detachable handle, the detachable handle may be used to create one or more interference fits with the disposed stylet handle.  FIG. 7A  is a schematic longitudinal cross-sectional view of the embodiment of the detachable handle shown in  FIG. 3C  with a portion of a stylet handle disposed entirely in a hollow center region of the detachable handle, according to the invention. In  FIG. 7A , a portion of the stylet handle  406  is shown disposed entirely in the hollow center region  316  of the detachable handle  302 . The two reduced-caliber regions  318  and  320  of the hollow center region  316  contact the stylet handle  406  and provide an interference fit, at least when the detachable handle is squeezed, around each portion of an outer surface of the stylet handle  406  contacting the reduced-caliber regions  318  and  320 . 
         [0042]    When a user grips the outer gripping surface  310  of the detachable handle  302 , the reduced-caliber regions  318  and  320  can be compressed against the portions of the stylet handle  406  contacting the reduced-caliber regions  318  and  320 , causing a frictional fastening, or an interference fit, between the detachable handle  302  and the stylet handle  406 . In alternate embodiments, the stylet handle  406  is disposed in the hollow center region  316  so as to only contact one reduced-caliber region or to contact more than two reduced-caliber regions. 
         [0043]    In one embodiment, a detachable handle is fabricated from a material that is compliant enough, such as silicone rubber, to form an interference fit by the compression created by application of a grip, or at least a squeeze, by a user to the outer gripping surface  310  of the detachable handle  302 . Typically, the tighter a user&#39;s grip around the outer gripping surface  310 , the greater the compression of the detachable handle  302  against the stylet handle  406  and, consequently, the stronger the interference fit. The strength of an interference fit can also be affected by the types of materials used to fabricate the outer surface of the stylet handle, as well as the types of materials used to fabricate a detachable handle. Thus, variable-strength interference fits can be created by fabricating detachable handles with materials of variable compliances. 
         [0044]      FIG. 7B  is a schematic longitudinal cross-sectional view of the embodiment of the detachable handle shown in  FIG. 3C  with a portion of a stylet handle disposed partially in a hollow center region of the detachable handle, according to the invention. In  FIG. 7B , the stylet handle  406  is shown contacting the reduced-caliber region  318  of the detachable handle  302  without contacting the reduced-caliber region  320  or extending out of the second end  308  of the detachable handle  302 . An interference fit may be created between the detachable handle  302  and the stylet handle  406  by a user gripping the outer gripping surface  310 , as described above, with reference to FIG.  7 A. In alternate embodiments, the stylet handle  406  is placed in contact with more than one reduced-caliber region without extending out of the second end  308  of the detachable handle  302 . 
         [0045]    In other embodiments, once a desired portion of a stylet handle and a proximal end of a lead each are disposed in a detachable handle, the detachable handle may be used to create one or more interference fits with both the engaged stylet handle and the proximal end of the lead.  FIG. 7C  is a schematic longitudinal cross-sectional view of the embodiment of the detachable handle shown in  FIG. 3C  with a portion of a stylet handle and a proximal end of a lead each disposed in a hollow center region of the detachable handle, according to the invention. In  FIG. 7C , the stylet handle  406  and the proximal end  410  of the lead  404  both are disposed in the hollow center region  316  of the detachable handle  302 . The stylet handle  406  is contacting the reduced-caliber region  320 , while the proximal end  410  of the lead  404  is contacting the reduced-caliber region  318 . Consequently, when the outer gripping surface  310  is gripped, or at least squeezed, by a user, an interference fit may be created with both the stylet handle  406  and the proximal end  410  of the lead  404 , as discussed above, with reference to  FIG. 7A . In some embodiments, the stylet handle  406  and/or the proximal end  410  of the lead  404  are disposed so as to be in contact with more than one reduced-caliber region. In some other embodiments, the proximal end  410  of the lead  404  contacts one or more reduced-caliber regions, while the stylet handle  406  is disposed so as to not contact a reduced-caliber region. 
         [0046]    The above specification, examples and data provide a description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention also resides in the claims hereinafter appended.