Magnet removal and replacement apparatus and methods for use with cochlear implants

Abstract

Apparatus and methods for installing a MR-compatible magnet apparatus into a cochlear implant.

1 - 31 . (canceled) 
     
     
         32 . A magnet apparatus insert for use with a cochlear implant, the cochlear implant including a housing with an antenna portion formed from a resilient elastomer, an antenna within the antenna portion, and an aperture within the antenna portion that extends at least partially through the cochlear implant housing, the magnet apparatus insert comprising:
 a housing portion replacement having a magnet housing formed from a resilient elastomer and configured to fit within the aperture; and   an MRI-compatible magnet apparatus embedded at least partially within the magnet housing.   
     
     
         33 . A magnet apparatus insert as claimed in  claim 32 , wherein
 the magnet housing of the housing portion replacement defines an outer perimeter and first and second longitudinal ends; and   the magnet apparatus insert further comprises a disk-shaped base associated with the first longitudinal end that extends radially beyond the outer perimeter.   
     
     
         34 . A magnet apparatus insert as claimed in  claim 33 , wherein
 the magnet apparatus insert further comprises a plurality of flanges that extend radially from the second longitudinal end of the magnet housing.   
     
     
         35 . A magnet apparatus insert as claimed in  claim 33 , wherein
 the magnet apparatus insert further comprises a flap that extends from the base to a location over the second longitudinal end of the housing.   
     
     
         36 . A magnet apparatus insert as claimed in  claim 32 , wherein
 the magnet housing of the housing portion replacement defines first and second longitudinal ends; and   the magnet apparatus insert further comprises a plurality of flanges that extend radially from at least one of the first and second longitudinal ends of the magnet housing.   
     
     
         37 . An apparatus as claimed in  claim 36 , wherein
 the MRI-compatible magnet apparatus includes a case and at least one protrusion, with an aperture that is configured to receive a bone screw, that extends outwardly from the case.   
     
     
         38 . A magnet apparatus as claimed in  claim 32 , wherein
 the MRI-compatible magnet apparatus comprises a case and at least one magnet within the case that is moveable relative to the case.   
     
     
         39 . A magnet apparatus as claimed in  claim 32 , wherein
 the MRI-compatible magnet apparatus comprises a case and a plurality of magnetic material particles within the case that are moveable relative to the case and to one another.   
     
     
         40 . A magnet apparatus as claimed in  claim 32 , wherein
 the housing portion replacement comprises a drug eluting housing portion replacement.   
     
     
         41 - 59 . (canceled) 
     
     
         60 . A method for use with a cochlear implant in a patient, the cochlear implant including a housing with an antenna portion formed from a resilient material and having a top side that faces skin and a bottom side that faces bone, an antenna within the antenna portion, a magnet pocket within the antenna portion, and a magnet within the magnet pocket, the method comprising the steps of:
 forming an incision in the skin;   removing the magnet from the housing without removing the cochlear implant from the patient; and   replacing the magnet with an MRI-compatible magnet apparatus.   
     
     
         61 . A method as claimed in  claim 60 , wherein
 the step of forming an incision comprising forming an incision that is either directly over the antenna portion or in front of the antenna portion.   
     
     
         62 . A method as claimed in  claim 60 , wherein
 the step of removing the magnet comprises removing a portion of the resilient material from the cochlear implant housing along with the magnet; and   the step of replacing the magnet with an MRI-compatible magnet apparatus comprises inserting an insert, including a housing portion replacement and an MRI-compatible magnet apparatus that is at least partially embedded within the housing portion replacement, into the cochlear implant housing from which resilient material has been removed.   
     
     
         63 . A method as claimed in  claim 62 , wherein
 the housing portion replacement comprises a drug eluting housing portion replacement.   
     
     
         64 - 82 . (canceled) 
     
     
         83 . A magnet apparatus for use with an implantable medical device, the magnet apparatus comprising:
 a case;   at least one magnetic element within the case that is rotatable relative to the case; and   a bone anchor associated with the case that is configured to anchor the case to bone.   
     
     
         84 . A magnet apparatus as claimed in  claim 83 , wherein
 the bone anchor comprises a bone screw.   
     
     
         85 - 89 . (canceled) 
     
     
         90 . A magnet apparatus as claimed in  claim 83 , wherein
 the case is at least partially embedded within a housing portion replacement.   
     
     
         91 . A magnet apparatus as claimed in  claim 90 , wherein
 the housing portion replacement comprises a drug eluting housing portion replacement.   
     
     
         92 . A magnet apparatus as claimed in  claim 83 , further comprising:
 a stiff strap with an anchor aperture secured to the case.   
     
     
         93 - 94 . (canceled) 
     
     
         95 . A magnet apparatus as claimed in  claim 83 , further comprising the step of
 a protrusion for mechanically interconnecting the case to a portion of the implantable medical device.   
     
     
         96 . A magnet apparatus as claimed in  claim 83 , wherein
 the case defines a central axis;   a magnet frame is located within the case and rotatable relative to the case about the central axis; and   the at least one magnetic element comprises a plurality of elongate diametrically magnetized magnets that are located in the magnet frame, the magnets defining a longitudinal axis and a N-S direction and being freely rotatable about the longitudinal axis relative to the magnet frame.   
     
     
         97 - 102 . (canceled)