Abstract:
The present invention involves a magnetic embolization apparatus for embolizing an aneurysm of a blood vessel. The apparatus includes a coiled element adapted for insertion within an aneurysm of a blood vessel, the coiled element shaped to be retained within the aneurysm, and one or more permanent magnetic segments carried by the coiled element to internally induce a magnetic field from within the aneurysm to control a magnetic field controllable embolic to embolize the aneurysm.

Description:
FIELD OF THE INVENTION 
     The invention relates, in general, to an apparatus and method for forming an occlusion in a mammalian body, and, in particular to an apparatus and method for internally inducing a magnetic field in an aneurysm to embolize the aneurysm with a magnetically-controllable substance. 
     BACKGROUND 
     Like all parts of the body, the brain is composed of living cells that require a blood supply to provide oxygen and nutrients. A hemorrhage in a blood vessel in the brain or in the space closely surrounding the brain is a common cause of strokes. Hemorrhage refers to bleeding into the brain, usually because of a problem with a blood vessel. The problem is often an aneurysm. 
     An aneurysm is an abnormal bulging outward of blood vessel wall. The wall may smoothly bulge outward in all directions (a fusiform aneurysm) or it may form a sack arising from one wall (a saccular aneurysm). If the aneurysm ruptures, a hemorrhage occurs. This can compress and irritate the surrounding blood vessels, resulting in a reduced supply of oxygen and nutrients to the cells, possibly causing a stroke. 
     Aneurysms can be treated from outside the blood vessel using surgical techniques or from inside the blood vessel using endovascular techniques. Endovascular treatment of an aneurysm is performed using a catheter. X-ray, magnetic resonance imaging (MRI) equipment, or other visualization equipment may be used to view the progress during the procedure. 
     A magnetically directable embolic such as an acrylic, iron-containing glue as to fill or obliterate aneurysms. The embolic is delivered by means of a catheter and is directed into an aneurysm with an external magnetic field generated by a permanent magnet or electromagnetic device used for Stereotaxis procedures such as a prototype device made by Stereotaxis Inc. of St. Louis, Mo. An example of such a device is shown and described in U.S. Pat. No. 6,014,580 to Blume, et al. Problems with this approach include that the Stereotaxis machine is cumbersome and expensive and, in some cases, the external magnetic field produced by the Stereotaxis machine is not strong enough to control delivery of the iron-containing, magnetically-directable glue into the aneurysm. 
     SUMMARY OF THE INVENTION 
     An aspect of the present invention involves a magnetic embolization apparatus for embolizing an aneurysm of a blood vessel. The apparatus includes a coiled element adapted for insertion within an aneurysm of a blood vessel, the coiled element shaped to be retained within the aneurysm, and one or more permanent magnetic segments carried by the coiled element to internally induce a magnetic field from within the aneurysm to control a magnetic field controllable embolic to embolize the aneurysm. 
     An additional aspect of the present invention involves a magnetic embolization apparatus for embolizing an aneurysm of a blood vessel. The apparatus includes a coiled element adapted for insertion within an aneurysm of a blood vessel, the coiled element shaped to be retained within the aneurysm, and one or more permanent magnetic segments carried by the coiled element to internally induce a magnetic field from within the aneurysm to control a magnetic field controllable embolic to embolize the aneurysm. 
     A further aspect of the present invention involves a magnetic embolization apparatus for embolizing an aneurysm of a blood vessel. The apparatus includes an element adapted for insertion within an aneurysm of a blood vessel, the element shaped to be retained within a dome of the aneurysm, and one or more permanent magnetic segments carried by the element in a location so as to be located in a top, central part of the dome of the aneurysm and adapted to internally induce a magnetic field from within the aneurysm to control a magnetic field controllable embolic to embolize the aneurysm. 
     Another aspect of the invention involves a magnetic embolization apparatus for embolizing an aneurysm of a blood vessel. The apparatus includes an element adapted for insertion within an aneurysm of a blood vessel, an electromagnet carried by the element to internally induce a magnetic field from within the aneurysm to control a magnetic field controllable embolic to embolize the aneurysm, and a guide wire having a lead wire for supplying electrical current to the electromagnet and a return wire for returning electrical current from the electromagnet. 
     An additional aspect of the invention involves a magnetic embolization apparatus for embolizing an aneurysm of a blood vessel. The apparatus includes a catheter including a distal portion adapted for insertion within an aneurysm of a blood vessel, and an electromagnet carried by the distal portion of the catheter to internally induce a magnetic field from within the aneurysm to control a magnetic field controllable embolic to embolize the aneurysm. 
     A further aspect of the invention involves a magnetic embolization apparatus for embolizing an aneurysm of a blood vessel. The apparatus includes a catheter having a distal portion adapted for insertion within an aneurysm of a blood vessel, and a permanent magnet carried by the distal portion of the catheter to internally induce a magnetic field from within the aneurysm to control a magnetic field controllable embolic to embolize the aneurysm. 
     Another aspect of the invention involves a magnetic embolization apparatus for embolizing an aneurysm of a blood vessel. The apparatus includes a guide wire including a distal end, a catheter including a distal portion adapted for insertion within an aneurysm of a blood vessel and an elongated lumen slidably receiving the guide wire and adapted to deliver a magnetic field controllable embolic to the aneurysm, an element connected to the distal end of the guide wire, the element adapted for insertion within the aneurysm, and a magnet carried by the element to internally induce a magnetic field from within the aneurysm to control the magnetic field controllable embolic to embolize the aneurysm. 
     A further aspect of the present invention involves a magnetic embolization apparatus for embolizing an aneurysm of a blood vessel. The apparatus includes a guide wire having a distal end, a catheter including a distal portion adapted for insertion within an aneurysm of a blood vessel and including first and second lumens, the first lumen slidably receiving the guide wire and the second lumen adapted to deliver the magnetic field controllable embolic to the aneurysm, an element connected to the distal end of the guide wire, the element adapted for insertion within the aneurysm, and a magnet carried by the element to internally induce a magnetic field from within the aneurysm to control the magnetic field controllable embolic to embolize the aneurysm. 
     An additional aspect of the present invention involves a method of embolizing an aneurysm of a blood vessel. The method includes delivering a magnetic embolization apparatus into an aneurysm with a lumen of a catheter, delivering a magnetic-field controllable embolic within the aneurysm with the same lumen of the catheter, and internally inducing a magnetic field with the magnetic embolization apparatus from within the aneurysm to control the magnetic-field controllable embolic to embolize the aneurysm. 
     Another aspect of the present invention involves a method of embolizing an aneurysm of a blood vessel. The method includes delivering a magnetic embolization apparatus into an aneurysm with a first lumen of a catheter, delivering a magnetic-field controllable embolic within the aneurysm with a second, different lumen of the same catheter, and internally inducing a magnetic field with the magnetic embolization apparatus from within the aneurysm to control the magnetic-field controllable embolic to embolize the aneurysm. 
     A still further aspect of the present invention involves a method of embolizing an aneurysm of a blood vessel. The method includes delivering a magnetic embolization apparatus into an aneurysm with a first catheter, delivering a magnetic-field controllable embolic within the aneurysm with a second, different catheter, and internally inducing a magnetic field with the magnetic embolization apparatus from within the aneurysm to control the magnetic-field controllable embolic to embolize the aneurysm. 
     Other features and advantages of the invention will be evident from reading the following detailed description, which is intended to illustrate, but not limit, the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings illustrate the design and utility of preferred embodiments of the present invention, in which similar elements are referred to by common reference numerals. 
     FIG. 1 is a side-elevational view of an embodiment of a catheter that may be used with the magnetic embolization apparatus. 
     FIG. 2 is a side-elevational view of a distal portion of the catheter illustrated in FIG. 1 in a blood vessel with an embodiment of the magnetic embolization apparatus shown disposed in an aneurysm. 
     FIGS. 3-5 illustrate alternative embodiments of the magnetic embolization apparatus. 
     FIG. 6 is a view similar to FIG. 2, but with a magnetically directable embolic delivery catheter shown next to the magnetic embolization apparatus catheter. 
     FIG. 7 is view similar to FIG. 2, but with an embodiment of a dual lumen catheter shown. 
     FIG. 8 is side-elevational view of a distal portion of a catheter with a further embodiment of a magnetic embolization apparatus shown. 
     FIG. 9 is a cross-sectional view of a distal portion of a catheter including a further embodiment of a magnetic embolization apparatus disposed therein. 
     FIG. 10 is a cross-sectional view of a distal portion of a catheter including a still further embodiment of a magnetic embolization apparatus disposed therein. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to FIG. 1, an exemplary multi-section catheter  100  that may be used to deliver and deploy a magnetic embolization apparatus  105 , which is constructed in accordance with an embodiment of the invention, at a targeted aneurysm  107  (FIG. 2) will now be described. Although the invention will be described in terms of aneurysm treatment, it may also be adaptable for endovascular occlusion in arteries, veins, vascular malformations, and arteriovenous fistulas. The invention may also be used for forming an occlusion in other areas of a mammalian body. 
     The catheter  100  includes a distal section  110 , an intermediate section  120 , and a proximal section  130 . The sections decrease in flexibility from the proximal section  130  to the distal section  110 . 
     The distal section  110  is very flexible and soft to allow deep penetration into the extraordinary convolutions of the neurological vasculature without trauma. The magnetic embolization apparatus  105  is deployed from the distal section  110  of the catheter  100  at a distal end  135 . The distal section  110  may include one or more radio-opaque bands  140  to allow viewing of the position of the distal section under fluoroscopy. 
     A luer assembly  150  at the proximal section  130  of the catheter  100  accomodates a pusher, core, or guide wire  160 . The wire  160  may be made of any well-known guide wire material in the art such as stainless steel. The magnetic embolization apparatus  105  may be attached to a distal end of the wire  160 . The luer assembly  150  may also include a fluid port  165  for introducing and/or removing a magnetically controllable embolization substance and a power port  170  for connecting the catheter  100  to a power supply. The catheter  100  may also include any well-known steering assembly in the art for delivering the magnetic embolization apparatus  105  to the targeted aneurysm  107 . 
     With reference to FIG. 2, an embodiment of the magnetic embolization apparatus  105  will now be described. The apparatus  105  includes one or more magnetic segments  200  attached to an element shaped to retain or secure the apparatus  105  within the aneurysm  107 . The permanent magnetic segments  200  (and the permanent magnets described below) may be made out of a material that safely dissolves over time or loses its magnetization over time so that MRJ may be used post surgery. In the embodiment shown, the element is a Guglielmi Detachable Coil (GDC®) assembly  205  made of platinum and sold by Target Therapeutics, Inc. of Fremont, Calif. When the coil assembly  205  is deployed into the aneurysm  107 , the coil assembly  205  preferably has a convoluted configuration. This three-dimensional, convoluted configuration helps to secure the apparatus  105  in the aneurysm  107 . 
     In a preferred embodiment, the coil assembly  205  is detachably coupled to the wire  160  by a detachment mechanism  250 . Examples of detachment mechanisms that may be used include a mechanical detachment mechanism such as that described in U.S. Pat. No. 5,250,071 (“the &#39;71 patent”) to Palermo and an electrolytic detachment mechanism such as those described in U.S. Pat. No. 5,122,136 (“the &#39;136 patent”) to Guglielmi, et al. and U.S. Pat. No. 6,123,714 (“the &#39;714 patent) to Gia, et al. The &#39;71, &#39;136, and &#39;714 patents are incorporated by reference as though set forth in full. Preferably, an electrolytic detachment mechanism similar to those described in the &#39;136 patent or the &#39;714 patent is used. An electrolytic detachment mechanism includes an electrolytic, sacrificial joint that separates when a small electric current is applied therethrough. The &#39;136 patent describes a soldered electrolytic, sacrificial joint and the &#39;714 patent describes a solderless electrolytic, sacrificial joint. The wire  160  is preferably fine enough to allow an embolic to be delivered through the same lumen that the wire  160  is disposed within. 
     Although the magnetic embolization apparatus  105  has been described as having a three-dimensional, convoluted configuration, in alternative embodiments, the apparatus  105  may include other configurations. For example, with reference to FIG. 3, the magnetic embolization apparatus  105  may have a generally bullet-shaped configuration with a partially spherical magnetic section  252 . Alternatively, the apparatus  105  illustrated in FIG. 3 may have a completely spherical configuration and magnetic section. With reference to FIG. 4, the apparatus  105  may have an umbrella-like configuration with magnetic segments  254  located on struts  256  of the apparatus  105 . To deploy or retract the struts  256 , a reciprocating base  258  may be coupled to a control device (not shown) for controlling arms  260  of the apparatus  105 . Alternatively, struts may carry a magnetic, generally hemispherical dome member. With reference to FIG. 5, the apparatus  105  may include a diamond-shape fibered platinum coil assembly  262  sold by Target Therapeutics, Inc. of Fremont, Calif. All of the embodiments of the apparatus  105  described above have advantageous configurations because, once deployed in the aneurysm  107 , they concentrate the magnetic field near a central part of the dome  390  of the aneurysm  107 . This helps to draw the magnetically controllable embolic deeper into the aneurysm  107 , away from a neck  385  of the aneurysm  107 . This reduces the chances of the embolic escaping the aneurysm  107  or the embolic or portions of the embolic dislodging from the aneurysm  107 . It should also be noted that the apparatus  105  may come in a variety of sizes to accommodate different size aneurysms  107  and/or a variety of configurations to accommodate aneurysms  107  having different shapes. 
     With reference back to FIG. 2, the magnetic embolization apparatus  105  will now be described in use. The catheter  100  is introduced into the vasculature of a patient via a cannula or introducer sheath and snaked through the vasculature of the patient to the targeted aneurysm  107  by any well-known method in the art. X-ray, fluoroscopy or other well-know visualization techniques may be used to assist the physician in directing the catheter  100  to the targeted aneurysm  107 . The catheter  100  may be introduced over a guide wire such as the guide wire  106  to facilitate delivery of the catheter  100  to the targeted aneurysm  107 . During delivery of the distal portion  110  of the catheter  100  to the aneurysm site, the apparatus  105  may be located in the catheter  100 , for example, in the distal portion  110  of the catheter  100 . Alternatively, the apparatus  105  may be introduced through the catheter  100  with the help of the wire  160  after the catheter  100  is directed to the targeted aneurysm site. The distal end  135  of the catheter  100  may be positioned at the aneurysm site adjacent the neck  385  of the aneurysm  107 , at the neck  385  of the aneurysm  107 , or within the aneurysm  107 . 
     Once the distal end  135  of the catheter  100  is delivered to the aneurysm  107 , the apparatus  105  may be deployed within the aneurysm  107 . This may be accomplished by advancing the pusher wire  160  distally through the catheter  100 . Preferably, the apparatus  105  has a pre-shaped memory so that the apparatus  105  will automatically deploy into the convoluted, three-dimensional configuration shown in FIG. 2 when the apparatus  105  is advanced into the aneurysm  107 . In an alternative embodiment, the catheter  100  may include a sheath that is retracted to deploy the apparatus  105 . In the embodiments of the apparatus  105  illustrated in FIGS. 3-5, the apparatus  105  is positioned in the aneurysm  107  so that the magnet portion  252 ,  254 ,  260  is positioned near a top center of the dome  390  of the aneurysm  107 . The configuration of the apparatus  105  helps to secure the apparatus  105  within the aneurysm  107 . 
     Next, the distal end  135  of the catheter  100  is centered within the dome  390  of the aneurysm  107 , and a magnetically controllable embolic such as an acrylic, iron-containing glue that hardens over time is delivered to the aneurysm  107  via the same lumen of the catheter  100  as that through which the apparatus  105  and the wire  160  are introduced. In an alternative embodiment, the embolic may have a different composition. For example, the embolic may be made of a composition that loses its magnetic controllability so that MRI may be used post surgery. The one or more permanent magnets  200  of the apparatus  105  internally attracts, from within the aneurysm  107 , the iron-containing embolic to the one or more magnets  200  at the dome  390  of the aneurysm  107 , filling the aneurysm  107 . The apparatus  105  may be detached from the wire  160  using the detachment mechanism  250  before or after the embolic is delivered to the aneurysm  107 . Further, if the apparatus  105  is detached from the wire  160  after the embolic is delivered to the aneurysm  107 , the apparatus  105  may be detached from the wire  160  after the embolic has sufficiently hardened or polymerized in the aneurysm  107 . 
     The apparatus  105  is left in the aneurysm  107  and the catheter  100  is withdrawn from the patient&#39;s body. In an alternative embodiment, the apparatus  105  may not be detached from the wire  160  (no detachment mechanism  250 ) after the apparatus  105  is deployed in the aneurysm  107 . The magnetically controllable embolic may be introduced into the aneurysm  107  after the apparatus  105  is deployed in the aneurysm  107 , and after a period of time that is sufficient to magnetically induce the embolic to fill the aneurysm  107  and allow the embolic to partially polymerize, the apparatus is retracted into the distal portion  110  of the catheter  100  and the catheter  100  is withdrawn with the apparatus  105  therein. 
     With reference to FIG. 6, in an alternative apparatus and embolic delivery method, the catheter  100  may be used to deliver and deploy the apparatus  106  to the targeted aneurysm site in the manner described above, and, instead of deliverying the magnetically controllable embolic through the same catheter, a separate embolic delivery catheter  265  may be used to deliver the embolic to the aneurysm  107 . 
     With reference to FIG. 7, in a further embodiment, the catheter  100  may be a dual-lumen catheter defined by respective lumen walls. The apparatus  105  may be delivered to the targeted aneurysm  107  using the wire  160  via a first lumen  267 , and the magnetically controllable embolic may be delivered to aneurysm  107  via a second lumen  269 . 
     Although the magnetic embolization apparatus  105  has been described as including a permanent magnet  200 , in alternative embodiments, the detachable embolization apparatus may include an electromagnet that is used to internally induce a magnetic field within the aneurysm  107  for embolizing the aneurysm  107  by running electrical current through the electromagnet. 
     For example, with reference to FIG. 8, an embodiment of an electromagnetic detachable embolization apparatus  500  is shown. The apparatus  500  includes a curvilinear, toroid-shaped electromagnet  503  and a pair of wire loops  520  to help secure the apparatus  500  within the aneurysm  107 . In alternative embodiments, the electromagnet may have different configurations besides a toroidal, curvilinear configuration. The electromagnet  503  and the wire loops  520  are coupled to a guide wire  522 . The guide wire  522  may include an insulated lead wire  505  and return wire  515  coupled to a power source  517  near the proximal section  130  of the catheter  100 . Although not shown, the guide wire  522  may include a detachment mechanism, as described above. 
     The electromagnet  503  includes a main wire  525 , an insulated structural support wire  535 , a first insulating separator  545 , and a second insulating separator  555 . The main wire  525  has a lead end  565  electrically connected to the lead wire  505  and a return end  575  electrically connected to the return wire  515 . The first insulating separator  545  connects the lead wire  505  to a first portion  585  of the insulated structural support wire  535  and the second insulating separator  555  connects the return wire  515  to a second portion  595  of the insulated structural support wire  535 . The main wire  525  includes numerous coils  600  that together form the curvilinear, toroid shape of the electromagnet  503 . 
     In use, the catheter  100  is snaked through the vasculature of the patient to a targeted aneurysm  107  with the electromagnetic embolization apparatus  500  collapsed within the distal portion  100  of the catheter  100 . The apparatus  500  is deployed within the aneurysm  107  so that the electromagnet  503  is positioned near a top center of the dome  390  of the aneurysm  107 . The wire loops  520  hold the apparatus  500  securely within the aneurysm  107 . Current supplied by the power source  517  through the insulated lead wire  505  flows through the electromagnet  503 , electromagnetically and internally inducing a magnetic field in the aneurysm  107 . The current returns throughout the return wire  515 . In an alternative embodiment, the current may be returned through a return wire in the catheter body; however, returning the current through the wire  160  is more efficient. 
     Next, the magnetically controllable embolic is delivered to the aneurysm  107 . This may be done via the same catheter  100  as illustrated in FIG. 2, a separate embolic deliver catheter  265  as illustrated in FIG. 6, or a dual lumen catheter  100  as illustrated in FIG.  7 . The electromagnet  503  of the apparatus  500  attracts the iron-containing embolic to the electromagnet  503 , filling the aneurysm  107 . Once the aneurysm  107  is filled a sufficient amount and the embolic has hardened or polymerized a sufficient amount, the apparatus  500  may be detached, if a detachment mechanism exists, and left impregnated in the hardened embolic, within the aneurysm  107 . 
     In an alternative embodiment, the apparatus  500  may not be detached from the guide wire  522  (no detachment mechanism) after the apparatus  500  is deployed in the aneurysm  107 . The magnetically controllable embolic may be introduced into the aneurysm  107  after the apparatus  500  is deployed in the aneurysm  107 , and after a period of time that is sufficient to magnetically induce the embolic to fill the aneurysm  107  and allow the embolic to polymerize, the apparatus  500  is retracted into the distal portion  110  of the catheter  100  and the catheter  100  is withdrawn with the apparatus  500  therein. 
     With reference to FIG. 9, an embodiment of a magnetic embolization apparatus  700  constructed in accordance with a further embodiment of the invention will now be described. The apparatus  700  includes a coiled electromagnet  710  located in the catheter body in the distal portion  110  of the catheter  100 . Electrical current is supplied to the electromagnet  710  by a power source  720  via a lead wire  730  and is returned by a return wire  740 . A radio-opaque marker  750  may be located in the catheter body at the distal end  135  of the catheter  100  to assist in locating the distal portion  110  of the catheter  100  in the vasculature of the patient using fluoroscopy. A plug  760  may be located in the distal end  135  of the catheter  100  to prevent the magnetically directable embolic from being magnetically drawn into the distal portion  110  of the catheter  100  when the electromagnet  710  is actuated. 
     In use, the catheter  100  is snaked through the vasculature of the patient to the targeted aneurysm  107 . At the aneurysm  107 , the distal end  135  of the catheter  100  is positioned into the aneurysm  107 , near the dome  390 . The radio-opaque marker  135  may be used with conventional fluoroscopy equipment to assist in positioning the distal end  135  of the catheter  100 . The distal end of a separate embolic deliver catheter  265 , as illustrated in FIG. 6, may be positioned in the aneurysm  107 , adjacent the catheter  100 , for delivering a magnetically controllable embolic to the aneurysm  107 . Alternatively, as illustrated in FIG. 7, the catheter  107  may be a dual lumen catheter with one lumen/lumen wall having a configuration similar to the catheter  100  illustrated in FIG.  9  and an adjacent lumen/lumen wall configured to deliver the embolic to the aneurysm  107 . Current is supplied by the power source  720  through the lead wire  730  to actuate the electromagnet  710 , electromagnetically and internally inducing a magnetic field  760  in the aneurysm  107 . The current returns throught the return wire  740 . The magnetically controllable embolic is delivered to the aneurysm  107 . The electromagnet  710  of the apparatus  500  attracts the iron-containing embolic along the magnetic field lines  760  induced by the electromagnet  503 , filling the aneurysm  107 . Once the aneurysm  107  is filled a sufficient amount and the embolic has hardened or polymerized a sufficient amount, the magnetic field  760  may be terminated by cutting off power to the electromagnet  710 , and the catheter  100  may be withdrawn. Advantages of this embodiment include a guide wire is not required to deliver the magnetic embolization apparatus, the apparatus  700  is not left in the aneurysm  107  after embolization, and the apparatus  700  does not have to be withdrawn through a partially or fully polymerized embolic in the aneurysm  107 . 
     With reference to FIG. 10, an embodiment of a magnetic embolization apparatus  800  constructed in accordance with a still further embodiment of the invention will now be described. The apparatus  800  includes a coiled permanent magnet  810  located in the catheter body in the distal portion  110  of the catheter  100 . Although magnetic configurations other than a coiled magnet may be used, a coiled magnet configuration or similar configuration is advantageous for providing the distal portion  110  of the catheter  100  with the requisite flexibility and to minimize catheter tip stiffness. A radio-opaque marker  850  may be located in the catheter body at the distal end  135  of the catheter  100  to assist in locating the distal portion  110  of the catheter  100  in the vasculature of the patient using fluoroscopy. A plug  860  may be located in the distal end  135  of the catheter  100  to prevent the magnetically directable embolic from being magnetically drawn into the distal portion  110  of the catheter  100 . 
     The method of use for the permanent magnetic embolization apparatus  800  is the same as that for the electromagnetic embolization apparatus  700 , except that current is not supplied to the permanent magnet  810  to induce a magnetic field because a magnetic field always exists at the distal portion  100 . 
     In a further embodiment of the invention, the electromagnet  710  of FIG. 9 may be combined with the permanent magnet  810  of FIG. 10 in the distal portion  110  of the catheter  100  to induce a stronger magnetic field in the aneurysm  107 . 
     The above-described embodiments of the invention internally induce a magnetic field, from within the aneurysm, to embolize the aneurysm with a magnetically-directable embolic. This eliminates the needs for a cumbersome and expensive superconducting electromagnetic device or large permanent magnet such as those used for Stereotaxis procedures and produces a stronger and more efficient magnetic field at the point of interest than that produced by such devices. 
     While embodiments and applications of this invention have been shown and described, it would be apparent to those in the field that many more modifications are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the appended claims.