Implant magnet system

Abstract

A magnetic alignment system that can form part of a cochlear implant system. The magnetic alignment system prevents substantial movement of a magnet of an implanted component during an MRI procedure or allows for easy removal of the magnet to facilitate the MRI procedure.

1 - 20 . (canceled) 
     
     
         21 . An apparatus, comprising:
 a mounting element comprising a central cavity; and   a magnet apparatus located in the central cavity, wherein   the magnet apparatus is releasably held within the mounting element via an arrangement that has, when the magnet apparatus is releasably held within the mounting element, a male portion extending into a female portion,   the magnet apparatus includes an extension at a topmost portion of the magnet apparatus that extends outwardly in a lateral direction, a top of the extension being at a topmost portion of the magnet apparatus,   the apparatus is a receiver component of a cochlear implant.   
     
     
         22 . The apparatus of  claim 21 , wherein:
 the female portion is part of the magnet apparatus.   
     
     
         23 . The apparatus of  claim 21 , wherein:
 the male portion remains with a remainder of the apparatus when the magnet apparatus is removed from the mounting element, and the female portion is removed with the magnet apparatus when the magnet apparatus is removed from the mounting element.   
     
     
         24 . The apparatus of  claim 21 , wherein:
 the male portion is curved; and   the female portion is curved.   
     
     
         25 . The apparatus of  claim 21 , wherein:
 the male portion has a curved section lying on a plane normal to a longitudinal axis of the magnet apparatus; and   the female portion has a curved section lying on a plane normal to the longitudinal axis of the magnet apparatus.   
     
     
         26 . The apparatus of  claim 21 , wherein:
 the male portion has a curved section lying on a plane normal to a longitudinal axis of the magnet apparatus; and   the female portion has a curved section lying on the plane normal to the longitudinal axis of the magnet apparatus.   
     
     
         27 . The apparatus of  claim 21 , wherein:
 the male portion and the female portion establish an interference fit to retain the magnet assembly in the mounting element.   
     
     
         28 . The apparatus of  claim 21 , wherein:
 a spring-type force is provided to aid in a fit of the magnet apparatus in the mounting element.   
     
     
         29 . An apparatus, comprising:
 an implantable MRI-compatible assembly of a cochlear implant configured to remain implanted during an MRI procedure, the assembly including an antenna configured to receive a coded signal and power from an external device and an electrode array configured to stimulate a recipient of the assembly; and   a removable magnet apparatus located in the assembly, the removable magnet apparatus being configured to be removed from the assembly prior to an MRI procedure with the assembly remaining implanted, wherein   with respect to a cross-section of the magnet apparatus lying on and parallel to a longitudinal axis of the magnet apparatus, starting from a bottom of the magnet apparatus, an outer profile of the magnet apparatus on the cross-section has a first straight section that extends upwards from a base of the magnet apparatus, and then, contiguous with the first straight section, the outer profile has a portion that is inboard of the first straight section, and then, contiguous with the portion that is inboard of the first straight section, the outer profile has a second straight section located a distance from the longitudinal axis that is further outboard than an inboard most portion of the portion inboard of the first straight section,   the assembly includes a portion that extends into the outer profile that has a portion inboard of the first straight section,   the cross-section includes a portion that extends outboard beyond the first and second straight sections, the portion that extends outboard being the outboard-most portion of the magnet apparatus, the portion that extends outboard being contiguous with the second straight section, and   the magnet apparatus is releasable held within the assembly.   
     
     
         30 . The apparatus of  claim 29 , wherein:
 the second straight section is located a distance from the longitudinal axis that is the same as that of the first straight section.   
     
     
         31 . The apparatus of  claim 29 , wherein:
 the cross-section includes a mirror image, relative to the longitudinal axis, of the first straight section, the portion inboard of the first straight section, and the second straight section.   
     
     
         32 . The apparatus of  claim 29 , wherein:
 the cross-section includes a flat portion that extends normal to the longitudinal axis, the flat portion extending from the first straight section to beyond the longitudinal axis.   
     
     
         33 . The apparatus of  claim 32 , wherein:
 the portion that extends outboard that is the outboard-most portion of the magnet apparatus is located at a topmost portion of the magnet apparatus.   
     
     
         34 . The apparatus of  claim 29 , wherein:
 the portion inboard of the first straight section is located in a bottom half of the magnet apparatus.   
     
     
         35 . The apparatus of  claim 29 , wherein:
 the portion inboard of the first straight section is the most inboard portion of the magnet apparatus.   
     
     
         36 . The apparatus of  claim 29 , wherein:
 magnet apparatus is located in a hole in the assembly;   the cross-section includes a portion that extends outboard beyond the first and second straight sections, the portion that extends outboard being the outboard-most portion of the magnet apparatus;   the assembly includes a cross-section lying on and parallel to the longitudinal axis of the magnet apparatus, the cross-section having a boundary of the hole; and   most of the boundary of the hole of the cross-section of the assembly, for most of the length of the hole as measured in the direction of the longitudinal axis, is located inboard of the outboard-most portion of the magnet apparatus.   
     
     
         37 . An implantable apparatus of a hearing prosthesis, comprising:
 means for retaining an external component of the hearing prosthesis against skin of a recipient of the implantable apparatus, the means for retaining includes an extension at a topmost portion of the means for retaining that extends outwardly in a lateral direction, a top of the extension being at a topmost portion of the means for retaining;   means for removable retaining the means for retaining to a remainder of the implantable apparatus; and   means for receiving a coded signal and power from the external component, wherein   the means for retaining is removable retained in the means for removably retaining.   
     
     
         38 . The implantable apparatus of  claim 37 , wherein:
 the apparatus is configured so that the means for retaining is removable from the means for removably retaining via the use of a tool.   
     
     
         39 . The implantable apparatus of  claim 37 , wherein:
 the apparatus is configured so that the means for retaining is removable from the means for removably retaining by drawing the means for retaining up and out of the means for removable retaining.   
     
     
         40 . The implantable apparatus of  claim 37 , wherein:
 the means for removably retaining includes a recess; and   the apparatus is configured so that the means for retaining is removable from the means for removably retaining by drawing the means for retaining up and out of the recess.   
     
     
         41 . The implantable apparatus of  claim 37 , wherein:
 the implantable apparatus is configured to be MRI-compliant by removing the means for retaining from a remainder of the implantable apparatus while the remainder of the implantable apparatus remains implanted in a recipient who is to undergo an MRI procedure.   
     
     
         42 . The implantable apparatus of  claim 37 , wherein:
 the implantable apparatus includes a stimulator unit of a cochlear implant in signal communication with the means for receiving the coded signal and power.   
     
     
         43 . The implantable apparatus of  claim 37 , wherein:
 the means for removably retaining includes a means for compression that removably retains the means for retaining.   
     
     
         44 . The implantable apparatus of  claim 37 , wherein:
 the means for removably retaining includes a means for interfering with the means for retaining to removably retain the means for retaining.