Medical lead system utilizing electromagnetic bandstop filters

Abstract

Medical lead systems utilizing electromagnetic bandstop filters are provide which can be utilized in a magnetic resonance imaging (MRI) environment for patients who have implanted medical devices. The medical lead system includes an implanted lead having at least one bandstop filter associated therewith, for attenuating current flow through the lead over a range of frequencies. The bandstop filter has an overall circuit Q wherein the resultant 3 dB bandwidth is at least 10 kHz. The values of capacitance and inductance of the bandstop filter are selected such that the bandstop filter is resonant at a selected center frequency. Preferably, the bandstop filter has an overall circuit Q wherein the resultant 10 dB bandwidth is at least 10 kHz. Such bandstop filters are backwards compatible with known implantable deployment systems and extraction systems.

1 . A medical lead system, comprising:
 a conductor lead having a proximal end, and an electrode in contact with biological cells at a distal end; and   at least one bandstop filter associated with the conductor, for attenuating current flow through the lead over a range of frequencies, the bandstop filter having an overall circuit Q wherein the resultant 3 dB bandwidth is at least 10 KHz, and wherein the bandstop filter comprises a capacitor in parallel with an inductor, said parallel capacitor and inductor placed in series with the conductor wherein values of capacitance and inductance are selected such that the bandstop filter is resonant at a selected center frequency.