Method and device to obstruct propagation of electromagnetic radiation induced in implanted electrical stimulators

Abstract

A device to improve the safety of head, heart, muscle and organ electrical stimulation devices during MRI scanning. The device consists of introducing an alternative second loop containing an energy dissipating device, with the possible addition of means to divert most of the induced energy during the MRI scanning into the second loop and into the energy dissipating device, thereby protecting the electrodes, the battery and the controlling electronics of the electrical stimulation device.

What is claimed is: 
     
         1 . A method of mitigating the effects of an electromagnetic energy induced on an implanted electrical stimulating device implanted in an animal, the implanted electrical stimulating device implanted in the animal with a surface and a volume, the implanted electrical stimulating device comprising:
 an at least one electrode, an at least one electric energy storage system and an at least one controlling electronics adapted to produce a desired stimulating signal at a desired stimulating frequency, and wires connecting as a first loop the at least one electrode, the at least one energy storage means and the at least one electronics controlling unit, the method comprising:   the act of adding at least one energy dissipating loop, the energy dissipating loop containing at least one energy dissipating device and at least one wire from the first loop wherein;   the at least one energy dissipating device is connected in parallel with the at least one electrode or with the at least one energy storage device or with the controlling electronics.   
     
     
         2 . The method of  claim 1  with an added at least one first device capable of offering a high impedance to the electromagnetic energy induced in the implanted electrical stimulating device, wherein,
 the first device capable of offering a high impedance to the electromagnetic energy induced in the implanted electrical stimulating device is connected in series with the at least one electrode and within the first loop. 
 
     
     
         3 . The method of  claim 2  wherein the at least one first device capable of offering a high impedance to the electromagnetic energy induced in the implanted electrical stimulating device is a coil or an active filter that is designed to block the electromagnetic energy induced in the implanted electrical stimulating device. 
     
     
         4 . The method of  claim 2  wherein the at least one first device capable of offering a high impedance to the electromagnetic energy induced in the implanted electrical stimulating device is an electric switch wherein the electric switch is configured to have a conductive state and a non-conductive state. 
     
     
         5 . The method of  claim 4  wherein the electric switch is configured to switch from the conductive state to the non-conductive state, or from the non-conductive state to the conductive state following electric command from either an external agent or from commando from the controlling electronics. 
     
     
         6 . The method of  claim 1  with an added at least one second device capable of offering a low impedance to the electromagnetic energy induced in the implanted electrical stimulating device while offering a high impedance to the desired stimulating signal at the desired stimulating frequency, wherein,
 the second device capable of offering a low impedance to the electromagnetic energy induced in the implanted electrical stimulating device is connected in series with the energy dissipating device and within the at least one energy dissipating loop. 
 
     
     
         7 . The method of  claim 6  wherein the at least one second device capable of offering a low impedance to the electromagnetic energy induced in the implanted electrical stimulating device is a capacitor or an active filter that is designed to block the stimulating signals at the desired stimulating frequency. 
     
     
         8 . The method of  claim 6  wherein the at least one second device capable of offering a low impedance to the electromagnetic energy induced in the implanted electrical stimulating device is an electric switch, wherein the electric switch is configured to have a conductive state and a non-conductive state which are mutually exclusive. 
     
     
         9 . The method of  claim 6  wherein the electric switch is configured to switch from the conductive state to the non-conductive state, or from the non-conductive state to the conductive state following electric command from either an external agent or from a commando from the controlling electronics. 
     
     
         10 . The method of  claim 1  with an added at least one third device capable of offering a high impedance to the electromagnetic energy induced in the implanted electrical stimulating device, wherein,
 the third device capable of offering a high impedance to the electromagnetic energy induced in the implanted electrical stimulating device is connected within the first loop, in series with the at least one energy storage device or with the at least one electronics controlling unit. 
 
     
     
         11 . The method of  claim 10  wherein the at least one third device capable of offering a high impedance to the electromagnetic energy induced in the implanted electrical stimulating device is either a coil or an op-amp configured to offer high impedance to the electromagnetic energy induced in the implanted electrical stimulating device while offering a low impedance to the desired stimulating signal at the desired stimulating frequency. 
     
     
         12 . The method of  claim 10  wherein the at least one third device capable of offering a high impedance to the electromagnetic energy induced in the implanted electrical stimulating device is an electric switch wherein the electric switch is configured to have a state one which is electrically conducting and a state two which is electrically insulating. 
     
     
         13 . A device for mitigating the effects of an electromagnetic energy induced on an implanted electrical stimulating device implanted in an animal, the device comprising:
 a first electrical network forming a first loop comprising at least one electrode implanted in the animal, at least one energy storage means at least one electronics controlling unit adapted to produce a desired stimulating signal at a desired stimulating frequency, and with wires to interconnect the at least one electrode, the at least one energy storage means and the at least one electronics controlling unit as the first loop,   a second electrical network forming a second loop, said second loop including at least an energy dissipation device and at least one of the wires that interconnect the at least one electrode implanted in the animal, the at least one energy storage means and the at least one electronics controlling unit,   wherein the energy dissipation device part of the second electrical network forming the second loop is connected in parallel electrical connection with the one electrode implanted in the animal or with the at least one energy storage means or with the at least one electronics controlling unit,   
     
     
         14 . The system according to  claim 13 , with an added at least first device capable of offering a high impedance to the electromagnetic energy induced in the implanted electrical stimulating device wherein,
 the first device capable of offering a high impedance to the electromagnetic energy induced in the implanted electrical stimulating device is within the first loop and connected in series with the at least one electrode or in series with the at least one energy storage means or in series with the at least one controlling electronics.   
     
     
         15 . The system according to  claim 14 , wherein the first device capable of offering a high impedance to the electromagnetic energy induced in the implanted electrical stimulating device is either a coil or an active filter that is designed to block the electromagnetic energy induced in the implanted electrical stimulating device and to pass the desired stimulating signal at the desired stimulating frequency. 
     
     
         16 . The system according to  claim 14 , wherein the first device capable of offering a high impedance to the electromagnetic energy induced in the implanted electrical stimulating device is an electric switch capable of either offering a low impedance to the electric current within the first loop or offering a high impedance to the electric current within the first loop. 
     
     
         17 . The system according to  claim 16 , wherein the continuity states of the at least one second electrical switch are controlled by a human operator via an action-at-a-distance as a radio wave or by the implanted electronics controlling unit. 
     
     
         18 . The system according to  claim 13 , further comprising at least one capacitor or one op-amp configured to provide a small impedance for the energy electromagnetic energy induced on the implanted electrical stimulating device, while configured to provide a large impedance for the desired stimulating signal at the desired stimulating frequency, the at least one capacitor or the at least one op-amp connected in series with the at least one energy dissipating device and configured to be part of the second loop. 
     
     
         19 . The system according to  claim 13 , wherein the at least one energy dissipation device is a resistor. 
     
     
         20 . The system according to  claim 13 , wherein the electromagnetic energy induction device is an MRI system. 
     
     
         21 . The system according to  claim 13 , wherein the one or more electrodes is/are configured to provide electrical stimulation in a brain. 
     
     
         22 . The system according to  claim 13 , wherein the one or more electrodes is/are configured to provide electrical stimulation in a heart. 
     
     
         23 . The system according to  claim 13 , wherein the one or more electrodes is/are configured to provide electrical stimulation in an animal organ.