Mri compatible medical leads

An MRI compatible lead, comprising:

• an elongated member having a proximal end and a distal end, the elongated member configured and arranged for insertion into a patient;
• at least one frequency dependent circuit comprising a first conductor and a second conductor, the first conductor comprising a first inductor defined by a first coiled conductor segment and the second conductor comprising a second inductor defined by a second coiled conductor segment;
• a first electrode in electrical communication with the first conductor, wherein the first electrode is disposed at the distal end of the elongated member;
• and a second electrode in electrical communication with the second conductor, wherein the second electrode is disposed at the distal end of the elongated member such that the second electrode is disposed axially from the first electrode;
• wherein the at least one frequency dependent circuit is configured to have a high impedance at an MRI scanner operating frequency in the MHz frequency range to thereby inhibit unwanted MRI related RF-induced tissue heating by the first electrode or the second electrode;
• wherein the first coiled conductor segment and the second coiled conductor segment are both disposed at the distal portion of the elongated member.

An MRI compatible lead, comprising:

• a single elongated member having a proximal end and a distal end, the elongated member configured and arranged for insertion into a patient;
• at least one RF filter disposed at least partially within the elongated member, the at least one RF filter comprising a frequency dependent circuit residing at a distal portion of the elongated member, the frequency dependent circuit comprising a first electrode coupled to a first conductor and a second electrode coupled to a second conductor, wherein the first electrode is disposed at the distal end of the elongated member, wherein the second electrode is disposed at the distal end of the elongated member such that the second electrode is disposed axially from the first electrode, wherein the RF filter is configured to:
• (a) have a high impedance at an MRI scanner operating frequency in the MHz frequency range to thereby inhibit unwanted tissue heating from at least one of the first electrode or the second electrode when in an MRI system;
• and (b) to allow at least one of (i) energy in the KHz range to be delivered along at least one of the first conductor or the second conductor to at least one of the first or the second electrode, and (ii) at least one of the first electrode or the second electrode to detect electrophysiology signals at low frequency and transmit the detected signals along at least one of the first conductor or the second conductor.

An MRI compatible lead, comprising:

• a first elongate conductor having opposing distal and proximal end portions;
• a first electrode attached to the distal end portion of the first conductor;
• and
• a frequency dependent circuit comprising an inductor and a capacitor in parallel, the frequency dependent circuit being in series with the first conductor and residing distal to the first elongate conductor, wherein the inductor and capacitor values are selected so that the frequency dependent circuit is a resonant circuit tuned to an MRI scanner operating frequency so that the frequency dependent circuit has a high impedance at the MRI scanner operating frequency in the MHz frequency range to thereby inhibit unwanted MRI related RF-induced tissue heating by the first electrode.