Mri-compatible implantable device

Abstract

A medical device containing a device for connecting the medical device to a substrate, for furnishing electrical impulses from the medical device to the substrate, for ceasing the furnishing of electrical impulses to the substrate, for receiving pulsed radio frequency fields, for transmitting and receiving optical signals, and for protecting the substrate and the medical device from currents induced by the pulsed radio frequency fields. The medical device contains a control circuit comprised of a parallel resonant frequency circuit.

1 - 40 . (canceled) 
     
     
         41 . A medical lead system, comprising:
 a lead wire configured for insertion into a venous system or tunneled through biological tissue, connecting at one end to an implantable medical device, and at an opposite end to an electrode in contact with biological cells; and   a bandstop filter associated with the lead wire, for attenuating current flow through the lead wire over a range of frequencies, the bandstop filter having an overall circuit Q wherein the resultant 3 db bandwidth is on the order of MHz, and wherein the bandstop filter comprises a capacitor in parallel with an inductor, said parallel capacitor and inductor placed in series with the lead wire, wherein values of capacitance and inductance are selected such that the bandstop filter is resonant at a selected center frequency.   
     
     
         42 . The system of  claim 41 , wherein the range of frequencies comprises a plurality of MRI pulsed frequencies. 
     
     
         43 . The system of  claim 41 , wherein the lead wire comprises a proximal section extending from the device, and a distal section, and wherein the bandstop filter is disposed between the proximal and distal sections. 
     
     
         44 . The system of  claim 41 , wherein the lead wire comprises a cardiac lead. 
     
     
         45 . The system of  claim 44 , wherein the cardiac lead incorporates the bandstop filter therein. 
     
     
         46 . The system of  claim 41 , wherein the lead wire comprises a stimulating lead. 
     
     
         47 . The system of  claim 46 , wherein the stimulating lead incorporates the bandstop filter therein. 
     
     
         48 . A medical lead system, comprising:
 a lead wire having a proximal end, and an electrode in contact with biological cells at a distal end; and   a bandstop filter associated with the lead wire, for attenuating current flow through the lead wire over a range of frequencies, the bandstop filter having an overall circuit Q wherein the resultant 3 db bandwidth is on the order of MHz, and wherein the bandstop filter comprises a capacitor in parallel with a conductor, said parallel capacitor and inductor placed in series with the lead wire wherein values of capacitance and inductance are selected such that the bandstop filter is resonant at a selected center frequency.   
     
     
         49 . A medical lead system, comprising:
 a lead wire having a proximal end, and an electrode in contact with biological cells at a distal end; and   a bandstop filter associated with the lead wire, for attenuating current flow through the lead wire over a range of frequencies, the bandstop filter having an overall circuit Q wherein the resultant 3 db bandwidth is on the order of MHz, and wherein the bandstop filter comprises a capacitor in parallel with an inductor, said parallel capacitor and inductor placed in series with the lead wire wherein values of capacitance and inductance are selected such that the bandstop filter is resonant at a selected center frequency.   
     
     
         50 . The system of  claim 48  or  49 , wherein the lead wire comprises a cardiac lead or a stimulating lead. 
     
     
         51 . The system of  claim 50 , wherein the cardiac lead or stimulating lead incorporates the bandstop filter therein. 
     
     
         52 . The system of  claim 50 , wherein the bandstop filter is disposed adjacent to the electrode. 
     
     
         53 . A medical lead system, comprising:
 a lead wire for insertion through biological tissue, connecting at one end to an implantable medical device, and at an opposite end to an electrode for contact with tissue; and   a resonant circuit operatively connected to the lead wire, for attenuating current flow through the lead wire over a range of frequencies, the resonant circuit having an overall circuit Q wherein the resultant 3 db bandwidth is on the order of MHz, and wherein the resonant circuit comprises a capacitor in parallel with an inductor, said parallel capacitor and inductor placed in series with the lead wire, wherein values of capacitance and inductance are selected such that the resonant circuit is resonant at a clinical scanner frequency.   
     
     
         54 . The system of  claim 53 , wherein the range of frequencies comprises a plurality of MRI frequencies. 
     
     
         55 . The system of  claim 53 , wherein the lead wire comprises a proximal section extending from the device, and a distal section, and wherein the resonant circuit is disposed between the proximal and distal sections. 
     
     
         56 . The system of  claim 53 , wherein the lead wire comprises a cardiac lead. 
     
     
         57 . The system of  claim 56 , wherein the cardiac lead incorporates the resonant circuit therein. 
     
     
         58 . The system of  claim 56 , wherein the resonant circuit is adjacent an electrode of the cardiac lead. 
     
     
         59 . The system of  claim 53 , wherein the lead wire comprises a stimulating lead. 
     
     
         60 . The system of  claim 59 , wherein the stimulating lead incorporates the resonant circuit therein. 
     
     
         61 . A medical lead system, comprising:
 a lead wire of an implantable medical device having a proximal end, and an electrode for contact with tissue at a distal end; and   a resonant circuit operatively connected to the lead wire, for attenuating current flow through the lead wire over a range of frequencies, the resonant circuit having an overall circuit Q wherein the resultant 3 db bandwidth is on the order of MHz, and wherein the resonant circuit comprises a capacitor in parallel with an inductor, said parallel capacitor and inductor placed in series with the lead wire wherein values of capacitance and inductance are selected such that the resonant circuit is resonant at a clinical scanner frequency.   
     
     
         62 . The system of  claim 61 , wherein the lead wire comprises a cardiac lead or a stimulating lead. 
     
     
         63 . The system of  claim 62 , wherein the cardiac lead or the stimulating lead incorporates the resonant circuit therein. 
     
     
         64 . The system of  claim 62 , wherein the resonant circuit is disposed adjacent to the electrode. 
     
     
         65 . A medical lead system, comprising:
 a lead wire, connecting at one end to an implantable medical device, and at an opposite end to an electrode in contact with a substrate; and   a parallel-resonant circuit associated with the lead wire, for preventing current at or near a resonant frequency from passing, the parallel-resonant circuit having an overall circuit Q wherein the resultant 3 db bandwidth is on the order of MHz, and wherein the parallel-resonant circuit comprises a capacitor in parallel with an inductor, said parallel capacitor and inductor placed in series with the lead wire, wherein values of capacitance and inductance are selected such that the parallel-resonant circuit is resonant at a clinical scanner frequency.   
     
     
         66 . The system of  claim 65 , wherein the current is reduced over a plurality of frequencies. 
     
     
         67 . The system of  claim 65 , wherein components of the parallel-resonant circuit are chosen so that the overall circuit Q will provide a desired amount of current flow at frequencies off of the resonant frequency. 
     
     
         68 . The system of  claim 65 , wherein the lead wire comprises a proximal section extending from the device, and a distal section, and wherein the parallel-resonant circuit is disposed between the proximal and distal sections. 
     
     
         69 . The system of  claim 65 , wherein the parallel-resonant circuit is disposed adjacent the electrode. 
     
     
         70 . The system of  claim 65 , wherein the lead wire comprises a cardiac lead. 
     
     
         71 . The system of  claim 70 , wherein the cardiac lead incorporates the parallel-resonant circuit therein. 
     
     
         72 . The system of  claim 65 , wherein the implantable medical device comprises a cardiac assist device and the substrate comprises a heart. 
     
     
         73 . The system of  claim 65 , wherein the lead wire comprises a stimulating lead. 
     
     
         74 . The system of  claim 73 , wherein the stimulating lead incorporates the parallel-resonant circuit therein. 
     
     
         75 . A medical lead system, comprising:
 a lead wire of an implantable medical device having a proximal end, and an electrode in contact with a substrate at a distal end; and   a parallel-resonant circuit associated with the lead wire, for preventing current at or near a resonant frequency from passing, the parallel-resonant circuit having an overall circuit Q wherein the resultant 3 db bandwidth is on the order of MHz, and wherein the parallel-resonant circuit comprises a capacitor in parallel with an inductor, said parallel capacitor and inductor placed in series with the lead wire wherein values of capacitance and inductance are selected such that the parallel-resonant circuit is resonant at a clinical scanner frequency.   
     
     
         76 . The system of  claim 75 , wherein the lead wire comprises a cardiac lead or a stimulating lead. 
     
     
         77 . The system of  claim 76 , wherein the cardiac lead or stimulating lead incorporates the parallel-resonant circuit therein. 
     
     
         78 . The system of  claim 76 , wherein the parallel-resonant circuit is disposed adjacent to the electrode. 
     
     
         79 . The system of  claim 75 , wherein the implantable medical device comprises a cardiac assist device and the substrate comprises a heart. 
     
     
         80 . The system of  claim 75 , wherein components of the parallel-resonant circuit are chosen so that the overall circuit Q will provide a desired amount of current flow at frequencies off of the resonant frequency. 
     
     
         81 . A medical lead system, comprising:
 a lead wire, connecting at one end to an implantable medical device, and at an opposite end to an electrode in contact with a substrate; and   a resonant circuit associated with the lead wire, for preventing current at or near a resonant frequency from passing, and wherein the resonant circuit comprises a capacitor in parallel with an inductor, said parallel capacitor and inductor placed in series with the lead wire, wherein values of capacitance and inductance are selected such that the resonant circuit is resonant at a frequency in the range of about 21.3 megahertz (MHz) to about 651 MHz.   
     
     
         82 . The system of  claim 81 , the resonant circuit having an overall circuit Q wherein the resultant 3 db bandwidth is on the order of MHz. 
     
     
         83 . The system of  claim 81 , wherein components of the parallel-resonant circuit are chosen so that the overall circuit Q will provide a desired amount of current flow at frequencies off of the resonant frequency. 
     
     
         84 . The system of  claim 81 , wherein components of the parallel-resonant circuit are chosen to choose a Q of the resonant circuit wherein a resultant 3 db bandwidth is on the order of MHz. 
     
     
         85 . The system of  claim 81  or  82 , wherein the current is reduced over a plurality of frequencies. 
     
     
         86 . The system of  claim 81  or  82 , wherein the lead wire comprises a proximal section extending from the device, and a distal section, and wherein the resonant circuit is disposed between the proximal and distal sections. 
     
     
         87 . The system of  claim 81  or  82 , wherein the resultant circuit is placed adjacent the electrode. 
     
     
         88 . The system of  claim 81  or  82 , wherein the lead wire comprises a cardiac lead. 
     
     
         89 . The system of  claim 88 , wherein the cardiac lead incorporates the resonant circuit therein. 
     
     
         90 . The system of  claim 81  or  82 , wherein the lead wire comprises a stimulating lead. 
     
     
         91 . The system of  claim 90 , wherein the stimulating lead incorporates the resonant circuit therein. 
     
     
         92 . A medical lead system, comprising:
 a lead wire of an implantable medical device having a proximal end, and an electrode in contact with a substrate at a distal end; and   a resonant circuit associated with the lead wire, for preventing current at or near a resonant frequency from passing, and wherein the resonant circuit comprises a capacitor in parallel with an inductor, said parallel capacitor and inductor placed in series with the lead wire wherein values of capacitance and inductance are selected such that the resonant circuit is resonant at frequency in the range of about 21.3 megahertz (MHz) to about 651 MHz.   
     
     
         93 . The system of  claim 92 , the resonant circuit having an overall circuit Q wherein the resultant 3 db bandwidth is on the order of MHz. 
     
     
         94 . The system of  claim 92 , wherein components of the parallel-resonant circuit are chosen so that the overall circuit Q will provide a desired amount of current flow at frequencies off of the resonant frequency. 
     
     
         95 . The system of  claim 92 , wherein components of the parallel-resonant circuit are chosen to choose a Q of the resonant circuit wherein a resultant 3 db bandwidth is on the order of MHz. 
     
     
         96 . The system of  claim 92  or  93 , wherein the lead wire comprises a cardiac lead or a stimulating lead. 
     
     
         97 . The system of  claim 96 , wherein the cardiac lead or stimulating lead incorporates the resonant circuit therein. 
     
     
         98 . The system of  claim 96 , wherein the resonant circuit is disposed adjacent to the electrode.