MRI-Safe Implant Electronics

Abstract

A power supply arrangement for an implantable electronic system is described. An MRI power supply arrangement cooperates with an implantable power supply circuit to provide a high output impedance for implanted circuitry during magnetic resonance imaging (MRI).

What is claimed is: 
     
         1 . A power supply arrangement for an implantable electronic system comprising:
 an implantable MRI power supply arrangement configured to cooperate with an implantable main power supply circuit and provide a high output impedance for implanted circuitry during magnetic resonance imaging (MRI).   
     
     
         2 . A power supply arrangement according to  claim 1 , wherein the MRI power supply arrangement includes an implantable MRI power supply circuit coupled to the implantable main power supply circuit and configured for providing a power supply voltage to the implanted circuitry during MRI. 
     
     
         3 . A power supply arrangement according to  claim 1 , wherein the MRI power supply arrangement includes an external MRI power supply circuit configured to be coupled to the implantable main power supply circuit to provide a power supply voltage to the implanted circuitry during MRI. 
     
     
         4 . A power supply arrangement according to  claim 3 , wherein the external MRI power supply circuit is battery powered. 
     
     
         5 . A power supply arrangement according to  claim 3 , wherein the external MRI power supply circuit is powered by RF pulses generated during MRI. 
     
     
         6 . A power supply arrangement according to  claim 3 , further comprising:
 an external holding magnet configured to cooperate with a corresponding implant magnet to establish a correct position of the external MRI power supply circuit with respect to the implantable power supply circuit.   
     
     
         7 . A power supply arrangement according to  claim 6 , wherein the external holding magnet is configured to be removable. 
     
     
         8 . A power supply arrangement according to  claim 1 , wherein the implanted circuitry is for a cochlear implant system. 
     
     
         9 . A method for providing electrical power to an implantable electronic system, the method comprising:
 cooperating between an implantable MRI power supply arrangement and an implantable main power supply circuit to provide a high output impedance for implanted circuitry during magnetic resonance imaging (MRI).   
     
     
         10 . A method according to  claim 9 , wherein the MRI power supply arrangement includes an implantable MRI power supply circuit configured to be coupled to the implantable main power supply circuit to provide a power supply voltage to the implanted circuitry during MRI. 
     
     
         11 . A method according to  claim 9 , wherein the MRI power supply arrangement includes an external MRI power supply circuit configured to be coupled to the implantable main power supply circuit to provide a power supply voltage to the implanted circuitry during MRI. 
     
     
         12 . A method according to  claim 11 , wherein the external MRI power supply circuit is arranged to be battery powered. 
     
     
         13 . A method according to  claim 11 , wherein the external MRI power supply circuit is arranged to be powered by RF pulses generated during MRI. 
     
     
         14 . A method according to  claim 11 , further comprising:
 cooperating between an external holding magnet and a corresponding implant magnet to establish a correct position of the external MRI power supply circuit with respect to the implantable power supply circuit.   
     
     
         15 . A method according to  claim 14 , wherein the external holding magnet is configured to be removable. 
     
     
         16 . A method according to  claim 9 , wherein the implanted circuitry is for a cochlear implant system. 
     
     
         17 . A power supply arrangement for an implantable electronic system comprising:
 means for cooperating between an MRI power supply arrangement and an implantable power supply circuit to provide a high output impedance for implanted circuitry during magnetic resonance imaging (MRI).   
     
     
         18 . A power supply arrangement according to  claim 17 , wherein the MRI power supply arrangement includes an implantable MRI power supply circuit coupled to the implantable power supply circuit for providing a power supply voltage to the implanted circuitry during MRI. 
     
     
         19 . A power supply arrangement according to  claim 17 , wherein the MRI power supply arrangement includes an external MRI power supply circuit coupled to the implantable power supply circuit for providing a power supply voltage to the implanted circuitry during MRI. 
     
     
         20 . A power supply arrangement according to  claim 19 , wherein the external MRI power supply circuit is arranged to be battery powered. 
     
     
         21 . A power supply arrangement according to  claim 19 , wherein the external MRI power supply circuit is arranged to be powered by RF pulses generated during MRI. 
     
     
         22 . A power supply arrangement according to  claim 19 , further comprising:
 means for cooperating between an external holding magnet and a corresponding implant magnet to establish a correct position of the external MRI power supply circuit with respect to the implantable power supply circuit.   
     
     
         23 . A power supply arrangement according to  claim 22 , wherein the external holding magnet is removable. 
     
     
         24 . A power supply arrangement according to  claim 17 , wherein the implanted circuitry is for a cochlear implant system.