MEDICAL DEVICE WITH AN ELECTRICALLY CONDUCTIVE ANTI-ANTENNA MEMBER
A lead includes a conductor having a distal end and a proximal end and a resonant circuit connected to the conductor. The resonant circuit has a resonance frequency approximately equal to an excitation signal's frequency of a magnetic resonance imaging scanner or a resonance frequency not tuned to an excitation signal's frequency of a magnetic resonance imaging scanner so as to reduce the current flow through a tissue area, thereby reducing tissue damage. The resonant circuit may be included in an adapter that provides an electrical bridge between a lead a medical device such as an electrode, sensor, or signal generator. The resonant circuit may also be included directly in the housing of a medical device.
1 . A lead, comprising:
a conductor having a distal end and a proximal end; and
a resonant circuit operatively connected to said conductor;
said resonant circuit having a resonance frequency approximately equal to an excitation signal's frequency of a magnetic resonance imaging scanner.
2 . The lead as claimed in claim 1 , wherein said resonant circuit is located at said distal end of said conductor.
3 . The lead as claimed in claim 1 , wherein said resonant circuit is located at said proximal end of said conductor.
4 . The lead as claimed in claim 1 , wherein said resonant circuit is an inductor connected in parallel with a capacitor.
5 . The lead as claimed in claim 1 , wherein said resonant circuit is an inductor connected in parallel with a capacitor and a resistor, said resistor and capacitor being connected in series.
6 . The lead as claimed in claim 1 , wherein said resonant circuit has a resonance frequency of about 64 MHz.
7 . The lead as claimed in claim 1 , further comprising:
a second resonant circuit operatively connected to said resonant circuit;
said second resonant circuit having a resonance frequency approximately equal to an excitation signal's frequency of a second magnetic-resonance imaging scanner.
8 . The lead as claimed in claim 7 , wherein said second resonant circuit is an inductor connected in parallel with a capacitor.
9 . The lead as claimed in claim 7 , wherein said second resonant circuit is an inductor connected in parallel with a capacitor and a resistor, said resistor and capacitor being connected in series.
10 . The lead as claimed in claim 7 , wherein said second resonant circuit has a resonance frequency of about 128 MHz.
11 . The lead as claimed in claim 2 , further comprising:
a second resonant circuit operatively connected to said resonant circuit;
said second resonant circuit having a resonance frequency approximately equal to an excitation signal's frequency of a second magnetic-resonance imaging scanner.
12 . The lead as claimed in claim 3 , further comprising:
a second resonant circuit operatively connected to said resonant circuit;
said second resonant circuit having a resonance frequency approximately equal to an excitation signal's frequency of a second magnetic-resonance imaging scanner.
13 . The lead as claimed in claim 6 , further comprising:
a second resonant circuit operatively connected to said resonant circuit;
said second resonant circuit having a resonance frequency equal to about 128 MHz.
14 . The lead as claimed in claim 1 , further comprising:
a heat receiving mass;
said heat receiving mass being located adjacent to said resonant circuit and dissipating the heat generated by said resonant circuit in a manner that is substantially non-damaging to surrounding tissue.
15 . The lead as claimed in claim 2 , further comprising:
a heat receiving mass;
said heat receiving mass being located adjacent to said resonant circuit and dissipating the heat generated by said resonant circuit in a manner that is substantially non-damaging to surrounding tissue.
16 . The lead as claimed in claim 3 , further comprising:
a heat receiving mass;
said heat receiving mass being located adjacent to said resonant circuit and dissipating the heat generated by said resonant circuit.
17 . The lead as claimed in claim 1 , further comprising:
a heat dissipating structure;
said heat dissipating structure being located adjacent to said resonant circuit and dissipating the heat generated by said resonant circuit in a manner that is substantially non-damaging to surrounding tissue.
18 . The lead as claimed in claim 2 , further comprising:
a heat dissipating structure;
said heat dissipating structure being located adjacent to said resonant circuit and dissipating the heat generated by said resonant circuit in a manner that is substantially non-damaging to surrounding tissue.
19 . The lead as claimed in claim 3 , further comprising:
a heat dissipating structure;
said heat dissipating structure being located adjacent to said resonant circuit and dissipating the heat generated by said resonant circuit.
20 . The lead as claimed in claim 7 , further comprising:
a third resonant circuit operatively connected to said resonant circuit;
said third resonant circuit having a resonance frequency approximately equal to an excitation signal's frequency of a third magnetic-resonance imaging scanner.
21 . The lead as claimed in claim 20 , further comprising:
a fourth resonant circuit operatively connected to said resonant circuit;
said fourth resonant circuit having a resonance frequency approximately equal to an excitation signal's frequency of a fourth magnetic-resonance imaging scanner.
22 . The lead as claimed in claim 21 , further comprising:
a fifth resonant circuit operatively connected to said resonant circuit;
said fifth resonant circuit having a resonance frequency approximately equal to an excitation signal's frequency of a fifth magnetic-resonance imaging scanner.
23 . The lead as claimed in claim 1 , wherein said resonant circuit is located near said distal end of said conductor.
24 . The lead as claimed in claim 1 , wherein said resonant circuit is located near said proximal end of said conductor.
25 . The lead as claimed in claim 1 , wherein the conductor is a conductor in a bipolar pacing lead circuit.
26 . The lead as claimed in claim 23 , wherein the conductor is a conductor in a bipolar pacing lead circuit.
27 . The lead as claimed in claim 24 , wherein the conductor is a conductor in a bipolar pacing lead circuit.
28 . The lead as claimed in claim 1 , wherein the conductor is a conductor in a unipolar pacing lead circuit.
29 . The lead as claimed in claim 1 , wherein the conductor is a conductor in a cardiac defibrillator lead.
30 . The lead as claimed in claim 1 , wherein the conductor is a conductor in a deep brain stimulating lead.
31 . The lead as claimed in claim 1 , wherein the conductor is a conductor in a nerve stimulating lead.
32 . The lead as claimed in claim 1 , wherein said resonant circuit is located between said proximal and distal ends of said conductor.
33 . A lead, comprising:
a conductor having a distal end and a proximal end;
said conductor being a coiled conductor having a resonant circuit thereof;
said resonant circuit having a resonance frequency approximately equal to an excitation signal's frequency of a magnetic resonance imaging scanner.
34 . The lead as claimed in claim 33 , wherein said resonant circuit is located at said distal end of said conductor.
35 . The lead as claimed in claim 33 , wherein said resonant circuit is located at said proximal end of said conductor.
36 . The lead as claimed in claim 33 , wherein said resonant circuit includes a capacitor connected to two distinct loops of said coiled conductor.
37 . The lead as claimed in claim 33 , wherein said resonant circuit includes an inductor formed from a portion of said coiled conductor and a capacitor connected to two distinct loops of said coiled conductor.
38 . The lead as claimed in claim 33 , wherein said resonant circuit includes an inductor formed from a portion of said coiled conductor and a capacitor and a resistor, said resistor and capacitor being connected to two distinct loops of said coiled conductor.
39 . The lead as claimed in claim 33 , wherein said resonant circuit has a resonance frequency of about 64 MHz.