Patent Publication Number: US-2020282202-A1

Title: Method and apparatus for temporarily anchoring sensory nerve stimulator (sns) leads to the skin of a patient during sns trialing and/or for temporarily anchoring other elongated flexible elements to the skin of a patient

Description:
REFERENCE TO PENDING PRIOR PATENT APPLICATIONS 
     This patent application: 
     (1) is a continuation-in-part of pending prior U.S. patent application Ser. No. 15/801,898, filed Nov. 2, 2017 by Anchor Innovation Medical, Inc. and Peter Sorensen et al. for METHOD AND APPARATUS FOR TEMPORARILY ANCHORING SENSORY NERVE STIMULATOR (SNS) LEADS TO THE SKIN OF A PATIENT DURING SNS TRIALING AND/OR FOR TEMPORARILY ANCHORING OTHER ELONGATED FLEXIBLE ELEMENTS TO THE SKIN OF A PATIENT (Attorney&#39;s Docket No. SUTURECONCEPTS-0708), which patent application claims benefit of:
         (i) prior U.S. Provisional Patent Application Ser. No. 62/416,527, filed Nov. 2, 2016 by Suture Concepts Inc. and Peter Sorensen et al. for METHOD AND APPARATUS FOR TEMPORARILY ANCHORING SENSORY NERVE STIMULATOR (SNS) LEADS TO THE SKIN OF A PATIENT DURING SNS TRIALING (Attorney&#39;s Docket No. SUTURECONCEPTS-7 PROV); and   (ii) prior U.S. Provisional Patent Application Ser. No. 62/428,186, filed Nov. 30, 2016 by Suture Concepts Inc. and Peter Sorensen et al. for METHOD AND APPARATUS FOR TEMPORARILY ANCHORING SENSORY NERVE STIMULATOR (SNS) LEADS TO THE SKIN OF A PATIENT DURING SNS TRIALING (Attorney&#39;s Docket No. SUTURECONCEPTS-8 PROV); and       

     (2) claims benefit of pending prior U.S. Provisional Patent Application Ser. No. 62/851,836, filed May 23, 2019 by Anchor Innovation Medical, Inc. and Peter Sorensen et al. for METHOD AND APPARATUS FOR TEMPORARILY ANCHORING SENSORY NERVE STIMULATOR (SNS) LEADS TO THE SKIN OF A PATIENT DURING SNS TRIALING AND/OR FOR TEMPORARILY ANCHORING OTHER ELONGATED FLEXIBLE ELEMENTS TO THE SKIN OF A PATIENT (Attorney&#39;s Docket No. SUTURECONCEPTS-11 PROV). 
     The four (4) above-identified patent applications are hereby incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to sensory nerve stimulators (SNS) in general, and more particularly to methods and apparatus for temporarily anchoring sensory nerve stimulator (SNS) leads to the skin of a patient during SNS trialing. This invention also relates to other elongated flexible elements, and for temporarily anchoring such other elongated flexible elements to the skin of a patient. 
     BACKGROUND OF THE INVENTION 
     In sensory nerve stimulation therapy (sometimes also referred to as “neuro modulation”), electrical leads are positioned adjacent to selected nerves of a patient and used to deliver electrical stimulation to those nerves so as to provide pain relief to the patient. 
     In one significant application of sensory nerve stimulation therapy, sensory nerve stimulator (SNS) leads are disposed adjacent to nerves in the spinal column of a patient, whereby to deliver electrical stimulation to those nerves and thereby provide pain relief to the patient. See, for example,  FIGS. 1 and 2 , which show an SNS system  5  disposed adjacent to the spinal column of a patient. SNS system  5  generally comprises SNS leads  10  and an SNS electrical pulse generator  15 . In use, SNS leads  10  are disposed in the spinal column of a patient so that the distal ends of the SNS leads (i.e., the ends of the leads containing the electrodes) lie adjacent to the nerves which are to be treated, and SNS electrical pulse generator  15  applies appropriate electrical pulses to the SNS leads so as to provide sensory nerve stimulation therapy to the patient. 
     In practice, it is common to conduct a “trial” of the SNS system so as to verify proper electrode placement and appropriate analgesic efficacy for the patient. After proper electrode placement and appropriate analgesic efficacy have been verified by trialing, the SNS system is thereafter permanently installed in the patient. 
     More particularly, during such “trialing”, the distal ends of the SNS leads (i.e., the ends of the leads containing the electrodes) are positioned adjacent to appropriate nerves in the spinal column of the patient, and the proximal ends of those SNS leads are brought out through the skin of the patient for connection to an SNS electrical pulse generator. During the trialing, the proximal ends of the SNS leads are held to the skin of the patient using tape, sutures, etc., and the SNS electrical pulse generator is secured to the skin of the patient using tape. After proper electrode placement and appropriate analgesic efficacy have been verified (e.g., typically after a week or so of trialing), the “permanent” SNS leads and the “permanent” SNS electrical pulse generator may then be implanted internally within the torso of the patient. 
     Unfortunately, the current practice of using tape and/or sutures to hold the SNS leads to the skin of the patient during trialing is not completely satisfactory. By way of example but not limitation, tape and/or sutures may allow unintended movement of the SNS leads during trialing, which could displace the SNS leads from their position adjacent to the appropriate nerves in the spinal column of the patient. By way of further example but not limitation, sutures may cause additional trauma to the patient. 
     Therefore, a primary object of the present invention is to provide an improved method and apparatus for temporarily anchoring SNS leads to the skin of a patient during SNS trialing. 
     SUMMARY OF THE INVENTION 
     The present invention comprises the provision and use of a novel method and apparatus for temporarily anchoring SNS leads to the skin of a patient during SNS trialing. More particularly, the present invention comprises the provision and use of a novel trial lead skin fixation device for temporarily anchoring SNS leads to the skin of a patient during SNS trialing. The trial lead skin fixation device is intended to be secured to the skin of the patient, and then an SNS lead is secured to the trial lead skin fixation device, during trialing. When trialing is completed and the SNS system is to be permanently installed in the body, the trial lead skin fixation device (with the SNS lead still attached thereto) is detached from the skin of the patient and the SNS lead is pulled from the body of the patient. The “permanent” SNS leads and the “permanent” SNS electrical pulse generator may then be implanted internally within the torso of the patient. 
     The present invention may also be used for temporarily anchoring other elongated flexible elements to the skin of a patient. 
     In one form of the invention, there is provided apparatus for securing an elongated flexible element to a patient, the apparatus comprising: 
     a base comprising an outer face and an inner face; 
     an adhesive applied to the inner face of the base; and 
     at least one pillar upstanding from the outer face of the base. 
     In another form of the invention, there is provided a method for securing an elongated flexible element to a patient, the method comprising: 
     providing apparatus comprising:
         a base comprising an outer face and an inner face;   an adhesive applied to the inner face of the base; and   at least one pillar upstanding from the outer face of the base;       

     securing the inner face of the base to the skin of the patient; and 
     securing the elongated flexible element to the apparatus, wherein the step of securing the elongated flexible element to the apparatus comprises positioning the elongated flexible element alongside the at least one pillar and against the outer face of the base. 
     In another form of the invention, there is provided apparatus for securing an elongated flexible element to a patient, the apparatus comprising: 
     a base comprising an outer face and an inner face; 
     an adhesive applied to the inner face of the base; and 
     a passageway formed in the outer face of the base, wherein the passageway is sized to receive the elongated flexible element. 
     In another form of the invention, there is provided a method for securing an elongated flexible element to a patient, the method comprising: 
     providing apparatus comprising:
         a base comprising an outer face and an inner face;   an adhesive applied to the inner face of the base; and   a passageway formed in the outer face of the base, wherein the passageway is sized to receive the elongated flexible element;       

     securing the inner face of the base to the skin of the patient; and 
     securing the elongated flexible element to the apparatus, wherein the step of securing the elongated flexible element to the apparatus comprises positioning the elongated flexible element within the passageway. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein: 
         FIGS. 1 and 2  are schematic views showing an SNS system disposed in the body of a patient; 
         FIGS. 3 and 4  are schematic views showing the top and bottom sides, respectively, of a novel trial lead skin fixation device formed in accordance with the present invention; 
         FIGS. 5 and 6  are exploded schematic views showing the top and bottom sides, respectively, of the trial lead skin fixation device of  FIGS. 3 and 4 ; 
         FIGS. 7 and 8  are schematic views showing the top and bottom sides, respectively, of the base and the cover of the trial lead skin fixation device of  FIGS. 3 and 4 ; 
         FIGS. 9-14  are schematic views showing use of the trial lead skin fixation device of  FIGS. 3 and 4 ; 
         FIG. 15  is a schematic view showing another trial lead skin fixation device formed in accordance with the present invention; 
         FIG. 16  is a schematic view showing still another trial lead skin fixation device formed in accordance with the present invention; 
         FIGS. 17-26  are schematic views showing yet another trial lead skin fixation device formed in accordance with the present invention; and 
         FIGS. 27-35  are schematic views showing still another trial lead skin fixation device formed in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention comprises the provision and use of a novel method and apparatus for temporarily anchoring SNS leads to the skin of a patient during SNS trialing. More particularly, the present invention comprises the provision and use of a novel trial lead skin fixation device for temporarily anchoring SNS leads to the skin of a patient during SNS trialing. The trial lead skin fixation device is intended to be secured to the skin of the patient, and then an SNS lead is secured to the trial lead skin fixation device, during trialing. When trialing is completed and the SNS system is to be permanently installed in the body, the trial lead skin fixation device (with the SNS lead still attached thereto) is detached from the skin of the patient and the SNS lead is pulled from the body of the patient. The “permanent” SNS leads and the “permanent” SNS electrical pulse generator may then be implanted internally within the torso of the patient. 
     The Novel Trial Lead Skin Fixation Device 
     More particularly, and looking now at  FIGS. 3-8 , there is shown a novel trial lead skin fixation device  20  formed in accordance with the present invention. Trial lead skin fixation device  20  generally comprises a base  25  and a cover  30 . A hinge  35  movably secures cover  30  to base  25 . 
     Base  25  has an outer (or front) face  40  and an inner (or rear) face  45 . A pair of notches  47  are formed in opposing ends of base  25 . A layer of adhesive (not shown in  FIGS. 3-8 ) covers outer face  40  of base  25 . A plurality of pillars (or posts)  55  are disposed on outer face  40  of base  25 . Pillars  55  preferably have a height greater than the diameter of the SNS leads (or other elongated flexible elements) which are to be secured to the skin of the patient. Pillars  55  are preferably formed of a compressible foam (e.g., foam formed out of polyurethane, polyethylene, etc.). Caps  60  are disposed on the tops of pillars  55 . Caps  60  are preferably formed out of a relatively stiff material, e.g., a sheet of plastic such as polyethylene terephthalate (PET). A plurality of lead-ins  65  are also disposed on outer face  40  of base  25 . Lead-ins  65  are preferably also formed of a compressible foam (e.g., foam formed out of polyurethane, polyethylene, etc.). Lead-ins  65  comprise slots  70 . Slots  70  in lead-ins  65  are aligned with notches  47  formed in base  25 . Caps  75  are disposed on the tops of lead-ins  65 . Caps  75  are preferably formed out of a relatively stiff material, e.g., a sheet of plastic such as polyethylene terephthalate (PET). Note that caps  75  do not cover slots  70  in lead-ins  65 . 
     Cover  30  has an outer (or front) face  80  and an inner (or rear) face  85 . A layer of adhesive (not shown in  FIGS. 3-8 ) covers inner face  85  of cover  30 . A plurality of holes  90  are formed in cover  30 . Note that holes  90  are sized and positioned such that when cover  30  is rotated about hinge  35  so that inner face  85  of cover  30  opposes outer face  40  of base  25 , pillars  55  and their caps  60  may be received in holes  90 . Note also that cover  30  is sized, relative to base  25 , such that cover  30  can fit between lead-ins  65  on base  25  when cover  30  is rotated about hinge  35  so that inner face  85  of cover  30  opposes outer face  40  of base  25 . 
     Hinge  35  generally comprises flexible elements  92  extending between base  25  and cover  30 . In one preferred form of the present invention, trial lead skin fixation device  20  comprises three flexible elements  92  separated by a pair of slots  93 . 
     Base  25 , cover  30  and hinge  35  are preferably formed out of a single sheet of material which is firm enough to enable base  25  and cover  30  to behave like stiff panels but flexible enough to allow elements  92  of hinge  35  to flex. In one preferred form of the invention, base  25 , cover  30  and hinge  35  are formed out of an ethylene-vinyl acetate (EVA) foam material. 
     A release liner  95  is disposed over outer (or front) face  40  of base  25  and inner (or rear) face  85  of cover  30 . Release liner  95  comprises holes  100  aligned with pillars  55  of base  25  and holes  105  aligned with holes  90  in cover  30 . Note that release liner  95  is sized, relative to base  25 , such that the release liner can fit between lead-ins  65  when the release liner is secured to base  25  and cover  30 . Release liner  95  also comprises a “pull tab”  107 . 
     An adhesive layer  110  is secured to inner face  45  of base  25 . More particularly, adhesive layer  110  is preferably in the form of an adhesive sheet which comprises an outer (or front) face  115  and an inner (or rear) face  120 . Adhesive layer  110  has its outer face  115  secured to inner face  45  of base  25 . A pair of notches  122  are formed in opposing ends of adhesive layer  110 . Notches  122  in adhesive layer  110  are aligned with notches  47  of base  25 . Adhesive layer  110  comprises an aggressive, pressure-sensitive adhesive adapted to adhere to the skin of a patient and to stay adhered to the skin of the patient for the full length of the trialing period, e.g., approximately one week. 
     A release liner  125  is mounted to inner face  120  of adhesive layer  110 . More particularly, release liner  125  comprises an outer (or front) face  130  and an inner (or rear) face  135 . Outer face  130  of release liner  125  is secured to inner face  120  of adhesive layer  110 . Release liner  125  comprises a “pull tab”  137 . 
     Use of the Novel Trial Lead Skin Fixation Device 
     In use, after a spinal needle has been used to advance an SNS lead through the skin of the patient and down to the appropriate nerve in the spinal column of the patient, novel trial lead skin fixation device  20  may be used to anchor that SNS lead to the skin of the patient during trialing. 
     More particularly, when a trial lead skin fixation device  20  is to be used to anchor an SNS lead to the skin of a patient, release liner  125  is first removed (e.g., using pull tab  137 ) from inner face  120  of adhesive layer  110  ( FIGS. 9 and 10 ). Then trial lead skin fixation device  20  is secured to the skin of the patient so that an SNS lead  10  emerging from the skin of the patient is disposed in one of a pair of aligned notches  47 ,  122  and adjacent to a lead-in  65 . Next, release liner  95  is removed (e.g., using pull tab  107 ) from outer face  40  of base  25  and inner face  85  of cover  30  ( FIGS. 11 and 12 ). Then the SNS lead is drawn through slot  70  of a lead-in  65 , woven in a “serpentine” manner around pillars  55 , and then out through slot  70  of the other lead-in  65 . This is preferably done while the SNS lead is held under a light tension so that pillars  55  compress radially inwardly somewhat so that the SNS lead slips under caps  60  of pillars  55 . Note that slots  70  of lead-ins  65  are preferably sized slightly smaller than the diameter of the SNS lead so that the SNS lead is lightly captured within slots  70 , beneath caps  75  of lead-ins  65 . See  FIG. 13 . 
     Note also that the adhesive positioned on outer face  40  of base  25  of trial lead skin fixation device  20  helps hold the SNS lead to outer face  40  of base  25 . 
     Next, cover  30  is rotated about hinge  35  so that inner face  85  of cover  30  engages outer face  40  of base  25 . As this occurs, pillars  55  and their caps  60  of base  25  are received in holes  90  of cover  30 , and the SNS lead is securely captured between outer face  40  of base  25  and inner face  85  of cover  30 . See  FIG. 14 . Note that as inner face  85  of cover  30  engages outer face  40  of base  25 , the adhesive on those faces helps hold cover  30  securely against base  25 . 
     During the trialing period, the aggressive, pressure-sensitive adhesive of adhesive layer  110  keeps trial lead skin fixation device  20  securely adhered to the skin of the patient for the complete trialing period, e.g., approximately one week. Note also that during the trialing period, the SNS lead is kept securely locked in position between cover  30  and base  25 , with the adhesive on inner face  85  of cover  30  and outer face  40  of base  25  keeping the cover “locked down” against the base, capturing the SNS lead therebetween. 
     Significantly, inasmuch as the SNS lead is woven about pillars  55  in a serpentine manner while under light tension, a capstan effect is created between the SNS lead and pillars  55 . More particularly, wrapping the SNS lead around the pillars  55  with at least partial turns causes the holding forces on the SNS lead to increase exponentially due to the capstan effect. This capstan effect significantly enhances the immobilization of the SNS lead relative to pillars  55  of trial lead skin fixation device  20  (and hence enhances the immobilization of the SNS lead relative to the skin of the patient). Stated another way, the capstan forces created between the SNS lead and pillars  55  provide high holding forces which significantly enhance the capture of the SNS lead to trial lead skin fixation device  20 , and hence significantly enhance capture of the SNS lead to the skin of the patient. 
     At the conclusion of the trialing period, trial lead skin fixation device  20  (with the SNS lead still attached thereto) is removed from the skin of the patient (note that the adhesives used to secure cover  30  to base  25  is so “sticky” that trial lead skin fixation device  20  would need to be cut open in order to release the SNS lead from the trial lead skin fixation device). Once trial lead skin fixation device  20  has been removed from the skin of the patient, the SNS lead is pulled from the body of the patient. The “permanent” SNS lead and the “permanent” SNS electrical pulse generator may then be implanted internally within the torso of the patient. 
     In connection with the foregoing, it will be appreciated that SNS therapy typically utilizes two SNS leads, so during trialing, two trial lead skin fixation devices  20  would typically be used, i.e., one trial lead skin fixation device  20  for each of the SNS leads. However, it should also be appreciated that, if desired, more than one trial lead skin fixation device  20  may be used for each SNS lead, e.g., such as for situations where increased “holding power” is desired. 
     Note that cover  30  need not be hingedly mounted to base  25 . More particularly, if desired, cover  30  may be formed separately from base  25 , and cover  30  may be united with base  25  by simply setting cover  30  over base  25 . 
     Additional Novel Trial Lead Skin Fixation Devices 
     Looking next at  FIG. 15 , there is shown another trial lead skin fixation device  200  formed in accordance with the present invention. Trial lead skin fixation device  200  is generally similar to trial lead skin fixation device  20  described above, except that release liner  95  of trial lead skin fixation device  20  is replaced by a first release liner  201  and a second release liner  202 , as will hereinafter be discussed in further detail. In addition, the base of the trial lead skin fixation device has a stiffening region  203 , as will also hereinafter be discussed in further detail. 
     More particularly, trial lead skin fixation device  200  generally comprises a base  205  and a cover  210 . A hinge  215  movably secures cover  210  to base  205 . 
     Base  205  has an outer (or front) face (not shown in  FIG. 15 , but analogous to outer face  40  of trial lead skin fixation device  20 ) and an inner (or rear) face (not shown in  FIG. 15 , but analogous to inner face  45  of trial lead skin fixation device  20 ). A pair of notches (not shown in  FIG. 15 , but analogous to notches  47  of trial lead skin fixation device  20 ) are formed in opposing ends of base  205 . A layer of adhesive (not shown in  FIG. 15 ) covers the outer face of base  205 . A plurality of pillars (or posts)  230  are disposed on the outer face of base  205 . Pillars  230  preferably have a height greater than the diameter of the SNS leads (or other elongated flexible elements) which are to be secured to the skin of the patient. Pillars  230  are preferably formed of a compressible foam (e.g., foam formed out of polyurethane, polyethylene, etc.). Caps  235  are disposed on the tops of pillars  230 . Caps  235  are preferably formed out of a relatively stiff material, e.g., a sheet of plastic such as polyethylene terephthalate (PET). A plurality of lead-ins  240  are also disposed on the outer face of base  205 . Lead-ins  240  are preferably also formed of a compressible foam (e.g., foam formed out of polyurethane, polyethylene, etc.). Lead-ins  240  comprise slots  245 . Slots  245  in lead-ins  240  are aligned with the aforementioned notches formed in base  205 . Caps  250  are disposed on the tops of lead-ins  240 . Caps  250  are preferably formed out of a relatively stiff material, e.g., a sheet of plastic such as polyethylene terephthalate (PET). Note that caps  250  do not cover slots  245  in lead-ins  240 . 
     Cover  210  has an outer (or front) face (not shown in  FIG. 15 , but analogous to outer face  85  of trial lead skin fixation device  20 ) and an inner (or rear) face (not shown in  FIG. 15 , but analogous to inner face  80  of trial lead skin fixation device  20 ). A layer of adhesive (not shown in  FIG. 15 ) covers the inner face of cover  210 . A plurality of holes  265  are formed in cover  210 . Note that holes  265  are sized and positioned such that when cover  210  is rotated about hinge  215  so that the inner face of cover  210  opposes the outer face of base  205 , pillars  230  and their caps  250  may be received in holes  265 . Note also that cover  210  is sized, relative to base  205 , such that cover  210  can fit between lead-ins  240  on base  205  when cover  210  is rotated about hinge  215  so that the inner face of cover  210  opposes the outer face of base  205 . 
     Hinge  215  generally comprises flexible elements  270  extending between base  205  and cover  210 . In this form of the invention, trial lead skin fixation device  200  comprises three flexible elements  270  separated by a pair of slots  275 . 
     Base  205 , cover  210  and hinge  215  are preferably formed out of a single sheet of material which is firm enough to enable base  205  and cover  210  to behave like stiff panels but flexible enough to allow elements  270  of hinge  215  to flex. In this preferred form of the invention, base  205 , cover  210  and hinge  215  are formed out of an ethylene-vinyl acetate (EVA) foam material. If desired, base  205  may comprise a stiffening region  203  which has enhanced stiffness so as to facilitate bending of cover  210  about hinge  215  without causing base  205  to bend. 
     A first release liner  201  is disposed over the outer face of base  205 . First release liner  201  comprises holes  285  aligned with pillars  230  of base  205 . Note that first release liner  201  is sized, relative to base  205 , such that the first release liner can fit between lead-ins  240  when the first release liner is secured to base  205 . First release liner  201  also comprises a “pull tab”  286 . A second release liner  202  is disposed over the inner face of cover  210 . Second release liner  202  comprises holes  292  aligned with holes  265  in cover  210 . Second release liner  202  comprises a “pull tab”  295 . 
     An adhesive layer (not shown in  FIG. 15 , but analogous to adhesive layer  110  of trial lead skin fixation device  20 ) is secured to the inner face of base  205 . This adhesive layer is preferably in the form of an adhesive sheet. A pair of notches (not shown in  FIG. 15 ) are formed in opposing ends of the adhesive layer. These notches in the adhesive layer are aligned with the notches of base  205 . The adhesive layer comprises an aggressive, pressure-sensitive adhesive adapted to adhere to the skin of a patient and to stay adhered to the skin of the patient for the full length of the trialing period, e.g., approximately one week. 
     A release liner (not shown in  FIG. 15 , but analogous to release liner  125  of trial lead skin fixation device  20 ) is mounted to the adhesive layer. The release liner comprises a “pull tab” (not shown in  FIG. 15 ). 
     In use, after a spinal needle has been used to advance an SNS lead through the skin of the patient and down to the appropriate nerve in the spinal column of the patient, novel trial lead skin fixation device  200  may be used to anchor that SNS lead to the skin of the patient during trialing. 
     More particularly, when a trial lead skin fixation device  200  is to be used to anchor an SNS lead to the skin of a patient, the release liner is removed from the adhesive layer and trial lead skin fixation device  200  is positioned against the skin of the patient so that the SNS lead  10  emerging from the skin of the patient is disposed in a notch formed in base  205  and adjacent to a lead-in  240 . Then first release liner  201  is removed (e.g., using pull tab  286 ) from the outer face of base  205 . Then the SNS lead is drawn through slot  245  of a lead-in  240 , woven in a “serpentine” manner around pillars  230 , and then out through slot  245  of the other lead-in  240 . This is preferably done while the SNS lead is held under a light tension so that pillars  230  compress radially inwardly somewhat so that the SNS lead slips under caps  235  of pillars  230 . Note that slots  245  of lead-ins  240  are preferably sized slightly smaller than the diameter of the SNS lead so that the SNS lead is lightly captured within slots  245 , beneath caps  250  of lead-ins  240 . 
     Next, second release liner  202  is removed (e.g., using pull tab  295 ) from the inner face of cover  210 . Cover  210  is then rotated about hinge  215  so that the inner face of cover  210  engages the outer face of base  205 . As this occurs, pillars  230  and their caps  235  of base  205  are received in holes  265  of cover  210 , and the SNS lead is securely captured between the outer face of base  205  and the inner face of cover  210 . Note that as the inner face of cover  210  engages the outer face of base  205 , the adhesive on those faces helps hold cover  210  securely against base  205 . 
     During the trialing period, the aggressive, pressure-sensitive adhesive of the adhesive layer on the inner face of base  205  keeps trial lead skin fixation device  200  securely adhered to the skin of the patient for the complete trialing period, e.g., approximately one week. Note also that during the trialing period, the SNS lead is kept securely locked in position between cover  210  and base  205 , with the adhesive on the inner face of cover  210  and the outer face of base  205  keeping the cover “locked down” against the base, capturing the SNS lead therebetween. 
     Significantly, inasmuch as the SNS lead is woven about pillars  230  in a serpentine manner while under light tension, a capstan effect is created between the SNS lead and pillars  230 . More particularly, wrapping the SNS lead around the pillars  230  with at least partial turns causes the holding forces on the SNS lead to increase exponentially due to the capstan effect. This capstan effect significantly enhances the immobilization of the SNS lead relative to pillars  230  of trial lead skin fixation device  200  (and hence enhances the immobilization of the SNS lead relative to the skin of the patient). Stated another way, the capstan forces created between the SNS lead and pillars  230  provide high holding forces which significantly enhance the capture of the SNS lead to trial lead skin fixation device  200 , and hence significantly enhance capture of the SNS lead to the skin of the patient. 
     At the conclusion of the trialing period, trial lead skin fixation device  200  (with the SNS lead still attached thereto) is removed from the skin of the patient (note that the adhesives used to secure cover  210  to base  205  is so “sticky” that trial lead skin fixation device  200  would need to be cut open in order to release the SNS lead from the trial lead skin fixation device). Once trial lead skin fixation device  200  has been removed from the skin of the patient, the SNS lead is pulled from the body of the patient. The “permanent” SNS lead and the “permanent” SNS electrical pulse generator may then be implanted internally within the torso of the patient. 
     In connection with the foregoing, it will be appreciated that SNS therapy typically utilizes two SNS leads, so during trialing, two trial lead skin fixation devices  200  would typically be used, i.e., one trial lead skin fixation device  200  for each of the SNS leads. However, it should also be appreciated that, if desired, more than one trial lead skin fixation device  200  may be used for each SNS lead, e.g., such as for situations where increased “holding power” is desired. 
     Note that cover  210  need not be hingedly mounted to base  205 . More particularly, if desired, cover  210  may be formed separately from base  205 , and cover  210  may be united with base  205  by simply setting cover  210  over base  205 . 
     Looking next at  FIG. 16 , there is shown another trial lead skin fixation device  300  formed in accordance with the present invention. Trial lead skin fixation device  300  is generally similar to trial lead skin fixation device  20  described above except that lead-ins  65  (and their caps  75 ) of trial lead skin fixation device  25  are omitted, and except that pillars  55  (and their caps  60 ) of trial lead skin fixation device  20  are laterally offset from notches  47  of base  25 . In addition, the base of the trial lead skin fixation device may have a stiffening region, as will also hereinafter be discussed in further detail. 
     More particularly, trial lead skin fixation device  300  generally comprises a base  305  and a cover  310 . A hinge  315  movably secures cover  310  to base  305 . 
     Base  305  has an outer (or front) face  316  and an inner (or rear) face (not shown in  FIG. 16 , but analogous to inner face  45  of trial lead skin fixation device  20 ). A pair of notches  326  are formed in opposing ends of base  305 . Alternatively, another pair of notches  328  are formed along one edge of base  305 . A layer of adhesive covers outer face  316  of base  305 . A plurality of pillars (or posts)  330  are disposed on the outer face of base  305 . Pillars  330  preferably have a height greater than the diameter of the SNS leads (or other elongated flexible elements) which are to be secured to the skin of the patient. Pillars  330  are preferably formed of a compressible foam (e.g., foam formed out of polyurethane, polyethylene, etc.). Caps  335  are disposed on the tops of pillars  330 . Caps  335  are preferably formed out of a relatively stiff material, e.g., a sheet of plastic such as polyethylene terephthalate (PET). 
     Cover  310  has an outer (or front) face (not shown in  FIG. 16 , but analogous to outer face  85  of trial lead skin fixation device  20 ) and an inner (or rear) face  336 . A layer of adhesive covers inner face  336  of cover  210 . A plurality of holes  350  are formed in cover  310 . Note that holes  350  are sized and positioned such that when cover  310  is rotated about hinge  315  so that the inner face of cover  310  opposes the outer face of base  305 , pillars  330  and their caps  335  may be received in holes  350 . 
     Hinge  315  generally comprises flexible elements  355  extending between base  305  and cover  310 . In this form of the invention, trial lead skin fixation device  300  comprises three flexible elements  355  separated by a pair of slots  360 . 
     Base  305 , cover  310  and hinge  315  are preferably formed out of a single sheet of material which is firm enough to enable base  305  and cover  310  to behave like stiff panels but flexible enough to allow elements  355  of hinge  315  to flex. In this preferred form of the invention, base  305 , cover  310  and hinge  315  are formed out of an ethylene-vinyl acetate (EVA) foam material. If desired, base  305  may comprise a stiffening region  363  which has enhanced stiffness so as to facilitate bending cover  310  about hinge  315  without causing base  305  to bend. 
     A first release liner (not shown in  FIG. 16 ) is disposed over outer face  316  of base  305 . The first release liner comprises holes aligned with pillars  330  of base  305 . The first release liner may also comprises a “pull tab”. A second release liner (not shown in  FIG. 16 ) is disposed over inner face  336  of cover  310 . The second release liner comprises holes aligned with holes  350  in cover  310 . The second release liner may also comprises a “pull tab”. 
     An adhesive layer (not shown in  FIG. 16 , but analogous to adhesive layer  110  of trial lead skin fixation device  20 ) is secured to the inner face of base  305 . This adhesive layer is preferably in the form of an adhesive sheet. A plurality of notches (not shown in  FIG. 16 ) are formed in the adhesive layer. These notches in the adhesive layer are aligned with notches  326 ,  328  of base  305 . The adhesive layer comprises an aggressive, pressure-sensitive adhesive adapted to adhere to the skin of a patient and to stay adhered to the skin of the patient for the full length of the trialing period, e.g., approximately one week. 
     A release liner (not shown in  FIG. 16 , but analogous to release liner  125  of trial lead skin fixation device  20 ) is mounted to the adhesive layer. The release liner may also comprise a “pull tab” (not shown in  FIG. 16 ). 
     In use, after a spinal needle has been used to advance an SNS lead through the skin of the patient and down to the appropriate nerve in the spinal column of the patient, novel trial lead skin fixation device  300  may be used to anchor that SNS lead to the skin of the patient during trialing. 
     More particularly, when a trial lead skin fixation device  300  is to be used to anchor an SNS lead to the skin of a patient, the release liner is removed from the adhesive layer and trial lead skin fixation device  300  is positioned against the skin of the patient so that the SNS lead  10  emerging from the skin of the patient is disposed in a notch formed in base  305 . Then the first release liner is removed (e.g., using a pull tab) from outer face  316  of base  305 . Then the SNS lead is woven in a “serpentine” manner around pillars  330 . This is preferably done while the SNS lead is held under a light tension so that pillars  330  compress radially inwardly somewhat so that the SNS lead slips under caps  335  of pillars  330 . 
     Next, the second release liner is removed (e.g., using a pull tab) from inner face  336  of cover  310 . Cover  310  is then rotated about hinge  315  so that the inner face of cover  310  engages the outer face of base  305 . As this occurs, pillars  330  and their caps  335  of base  305  are received in holes  350  of cover  310 , and the SNS lead is securely captured between outer face  316  of base  305  and inner face  336  of cover  310 . Note that as inner face  336  of cover  310  engages outer face  316  of base  305 , the adhesive on those faces helps hold cover  310  securely against base  305 . 
     During the trialing period, the aggressive, pressure-sensitive adhesive of the adhesive layer on the inner face of base  305  keeps trial lead skin fixation device  300  securely adhered to the skin of the patient for the complete trialing period, e.g., approximately one week. Note also that during the trialing period, the SNS lead is kept securely locked in position between cover  310  and base  305 , with the adhesive on the inner face of cover  310  and the outer face of base  305  keeping the cover “locked down” against the base, capturing the SNS lead therebetween. 
     Significantly, inasmuch as the SNS lead is woven about pillars  330  in a serpentine manner while under light tension, a capstan effect is created between the SNS lead and pillars  330 . More particularly, wrapping the SNS lead around the pillars  330  with at least partial turns causes the holding forces on the SNS lead to increase exponentially due to the capstan effect. This capstan effect significantly enhances the immobilization of the SNS lead relative to pillars  330  of trial lead skin fixation device  300  (and hence enhances the immobilization of the SNS lead relative to the skin of the patient). Stated another way, the capstan forces created between the SNS lead and pillars  330  provide high holding forces which significantly enhance the capture of the SNS lead to trial lead skin fixation device  300 , and hence significantly enhance capture of the SNS lead to the skin of the patient. 
     At the conclusion of the trialing period, trial lead skin fixation device  300  (with the SNS lead still attached thereto) is removed from the skin of the patient (note that the adhesives used to secure cover  310  to base  305  is so “sticky” that trial lead skin fixation device  300  would need to be cut open in order to release the SNS lead from the trial lead skin fixation device). Once trial lead skin fixation device  300  has been removed from the skin of the patient, the SNS lead is pulled from the body of the patient. The “permanent” SNS lead and the “permanent” SNS electrical pulse generator may then be implanted internally within the torso of the patient. 
     In connection with the foregoing, it will be appreciated that SNS therapy typically utilizes two SNS leads, so during trialing, two trial lead skin fixation devices  300  would typically be used, i.e., one trial lead skin fixation device  300  for each of the SNS leads. However, it should also be appreciated that, if desired, more than one trial lead skin fixation device  300  may be used for each SNS lead, e.g., such as for situations where increased “holding power” is desired. 
     Note that cover  310  need not be hingedly mounted to base  305 . More particularly, if desired, cover  310  may be formed separately from base  305 , and cover  310  may be united with base  305  by simply setting cover  310  over base  305 . 
     Looking next at  FIGS. 17-19 , there is shown yet another trial lead skin fixation device  400  formed in accordance with the present invention. Trial lead skin fixation device  400  generally comprises a base  405 . 
     Base  405  has a top (or outer or front) surface  410  and a bottom (or inner or rear) surface  415 . A series of intertwining passageways  420  are formed in top surface  410  of base  405 . Passageways  420  preferably have a depth greater than the diameter of the SNS leads (or other elongated flexible elements) which are to be secured to the skin of the patient. Passageways  420  may define a pillar (or post)  422  in top surface  410  of base  405 . A plurality of slots  425  are also formed in base  405 . Slots  425  in base  405  intersect passageways  420  formed in base  405 . In one preferred form of the invention, base  405  is formed out of a compressible material. 
     An adhesive layer  430  is secured to bottom surface  415  of base  405  (see  FIG. 19 ). More particularly, adhesive layer  430  is preferably in the form of an adhesive sheet which comprises an outer (or front) face  435  and an inner (or rear) face  440 . Adhesive layer  430  has its outer face  435  secured to bottom surface  415  of base  405 . Adhesive layer  430  comprises an aggressive, pressure-sensitive adhesive adapted to adhere to the skin of a patient and to stay adhered to the skin of the patient for the full length of the trialing period, e.g., approximately one week. 
     A release liner  445  is mounted to inner face  440  of adhesive layer  430 . Release liner  445  may comprise a “pull tab”. 
     In use, and looking now at  FIGS. 20-24 , after a spinal needle has been used to advance an SNS lead through the skin of the patient and down to the appropriate nerve in the spinal column of the patient, novel trial lead skin fixation device  400  may be used to anchor that SNS lead to the skin of the patient during trialing. 
     More particularly, when a trial lead skin fixation device  400  is to be used to anchor an SNS lead to the skin of a patient, release liner  445  is first removed (e.g., using a pull tab) from inner face  440  of adhesive layer  430 . Then trial lead skin fixation device  400  is secured to the skin of the patient so that an SNS lead  10  emerging from the skin of the patient is disposed in a slot  425  (see  FIG. 20 ). Next, the SNS lead is drawn, under slight tension, through passageways  420  and then out of base  405 . More particularly, and looking now at  FIGS. 21-23 , SNS lead  10  is slid, under slight tension, through passageways  420 , wrapped around pillar  422  twice, and crossed over slot  425  (via passageway  420 ) and exited out of trial lead skin fixation device  400 . It will be appreciated that SNS lead  10  can be tightened around pillar  422  by pulling on SNS lead  10  until there is no “slack”. Note that passageways  420  and slots  425  are preferably sized slightly larger than the diameter of the SNS lead so that the SNS lead is closely received within passageways  420  and slots  425 . Note also that where base  405  is formed out of a compressible material, passageways  420  and slots  425  can be sized so that base  405  can lightly grip the SNS lead received within passageways  420  and slots  425 . 
     Significantly, inasmuch as the SNS lead is woven through passageways  420  and about pillar  422  of base  405  in a serpentine manner while under light tension, a capstan effect is created between the SNS lead and pillar  422 . More particularly, wrapping the SNS lead around the pillar  422  with at least a partial turn causes the holding forces on the SNS lead to increase exponentially due to the capstan effect. This capstan effect significantly enhances the immobilization of the SNS lead relative to pillar  422  of trial lead skin fixation device  400  (and hence enhances the immobilization of the SNS lead relative to the skin of the patient). Stated another way, the capstan forces created between the SNS lead and pillar  422  provide high holding forces which significantly enhance the capture of the SNS lead to trial lead skin fixation device  400 , and hence significantly enhance capture of the SNS lead to the skin of the patient. 
     Lastly, a bandage  465  is placed over trial lead skin fixation device  400 . See  FIG. 24 . Bandage  465  provides additional holding power for securing trial lead skin fixation device  400  against the skin of the patient. 
     During the trialing period, the aggressive, pressure-sensitive adhesive of adhesive layer  430  and bandage  465  keep trial lead skin fixation device  400  securely adhered to the skin of the patient for the complete trialing period, e.g., approximately one week. Note also that during the trialing period, the SNS lead is kept securely locked in position within passageways  420 , particularly due to the capstan effect created with pillar  422 . 
     At the conclusion of the trialing period, trial lead skin fixation device  400  and bandage  465  (with the SNS lead still attached thereto) are removed from the skin of the patient. Once trial lead skin fixation device  400  has been removed from the skin of the patient, the SNS lead is pulled from the body of the patient. The “permanent” SNS lead and the “permanent” SNS electrical pulse generator may then be implanted internally within the torso of the patient. 
     In connection with the foregoing, it will be appreciated that SNS therapy typically utilizes two SNS leads, so during trialing, two trial lead skin fixation devices  400  would typically be used, i.e., one trial lead skin fixation device  400  for each of the SNS leads. By way of example but not limitation, two trial lead skin fixation devices  400  can be aligned side by side (see  FIG. 25 ) and/or in a staggered configuration (see  FIG. 26 ) on the skin of a patient. However, it should also be appreciated that, if desired, more than one trial lead skin fixation device  400  may be used for each SNS lead, e.g., such as for situations where increased “holding power” is desired. 
     Looking next at  FIGS. 27-35  there is shown another trial lead skin fixation device  500  formed in accordance with the present invention. 
     Trial lead skin fixation device  500  is generally similar to the trial lead skin fixation device shown in  FIGS. 3-14 , except that, among other things: 
     (i) one of the notches  47  in the base of the trial lead skin fixation device is omitted, and the other of the notches  47  in the base of the trial lead skin fixation device extends further into base  25  of the trial lead skin fixation device, and is wider at its mouth and tapers inwardly along its length—this tapering of notch  47  facilitates positioning the lead exiting from the patient into the notch and moving the lead down the length of the notch to the closed end of the notch; 
     (ii) the lead-in  65  associated with the extended, tapered notch  47  is omitted in order to provide the user with a direct, clear view of the extended, tapered notch, whereby to facilitate the user introducing the lead into the extended, tapered notch and moving the lead down the length of the extended, tapered notch to the closed end of the extended, tapered notch; and 
     (iii) the pair of slots  93  (which form a hinge line for the trial lead skin fixation device shown in  FIGS. 3-14 , so that cover  30  can be easily folded over base  25 ) are replaced by one or more depressions  505  located at the joinder of cover  30  and base  25  (see  FIGS. 30, 31 and 34 ) so as to define a hinge line for trial lead skin fixation device  500  (this hinge line allows cover  30  to be easily folded over base  25 ). 
     Note that in this form of the invention, during use, the lead extending out of the patient, through the extended, tapered notch  47 , around the pillars (or posts)  55  upstanding from base  25 , and then passing through slot  70  of the remaining lead-in  65 , is completely concealed by cover  30  of trial lead skin fixation device  500  until the lead emerges from the end of the trial lead skin fixation device. 
     Use of the Present Invention for Other Applications 
     It should be appreciated that the present invention may be used for applications other than temporarily anchoring SNS leads to the skin of a patient during SNS trialing. By way of example but not limitation, the present invention may also be used to secure other electrical leads, intravenous (IV) lines, catheters, sutures, and/or substantially any other elongated, flexible element, etc. to the skin of a patient. Significantly, by wrapping these leads, lines, catheters, sutures, and/or other elongated flexible elements at least partially around one or more curved objects (e.g., pillars, etc.), a capstan effect may be created which provides high holding forces for securing the leads, lines, catheters, sutures, and/or other elongated flexible elements to a patient. 
     Modifications of the Preferred Embodiments 
     It should be understood that many additional changes in the details, materials, steps and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the present invention, may be made by those skilled in the art while still remaining within the principles and scope of the invention.