Intravascular device including high voltage coaxial conductor wiring
Wiring is disclosed herein that is configured to supply IRE ablation signals through a catheter body and is resistant against dielectric breakdown, arcing, and noise during ablation. The wiring includes a highly conductive core, a conductive cover surrounding the core that has lower electrical and/or thermal conductivity than the core, and an insulative jacket surrounding the conductive cover. A catheter including such wiring may be suitable for supplying electrical signals to tissue to perform IRE ablation. In some examples, such a catheter can also be suitable for reversible electroporation and/or RF ablation.
1 . An intravascular device comprising:
an elongated shaft extending along a longitudinal axis and sized to traverse vasculature;
a distal section comprising a plurality of electrodes configured to deliver at least 900VDC for irreversible electroporation; and
a plurality of wires each electrically joined to a respective electrode of the plurality of electrodes, each of the wires of the plurality of wires extending through at least a portion of the elongated shaft, and each of the wires of the plurality of wires respectively comprising:
an electrically conductive core material comprising a first electrical conductivity,
an electrically conductive cover material comprising a second electrical conductivity less than the first electrical conductivity, the electrically conductive cover material circumscribing the electrically conductive core material, and
an insulative jacket circumscribing the electrically conductive cover material such that no electrical arc is generated between the plurality of wires during delivery of at least 900 Volts to each electrode.
2 . The intravascular device of claim 1 , the electrically conductive core material comprising about 12% to about 50% of silver.
3 . The intravascular device of claim 2 , the electrically conductive core material comprising about 28% to about 33% of silver.
4 . The intravascular device of claim 1 , the electrically conductive core material comprising about 12% to about 50% of copper.
5 . The intravascular device of claim 1 , the first electrical conductivity being about 4×10 7 S/m to about 6×10 7 S/m when measured at 20° C.
6 . The intravascular device of claim 1 , the second electrical conductivity being about 1×10 6 S/m when measured at 20° C.
7 . The intravascular device of claim 1 , the first electrical conductivity being at least ten times greater than the second electrical conductivity when measured at 20° C.
8 . The intravascular device of claim 1 ,
the electrically conductive core material comprising a first thermal conductivity, and
the electrically conductive cover material comprising a second thermal conductivity less than the first thermal conductivity.
9 . The intravascular device of claim 8 , the first thermal conductivity being about 300 W/mK to about 400 W/mK.
10 . The intravascular device of claim 8 , the second thermal conductivity being about 11.2 W/mK.
11 . The intravascular device of claim 8 , the first thermal conductivity being at least ten times the second thermal conductivity.
12 . The intravascular device of claim 1 , each of the wires of the plurality of wires comprising a resistance per length of wire measuring about 1.4 Ω/ft (4.6 Ω/m) to about 1.8 Ω/ft (5.8 Ω/m).
13 . The intravascular device of claim 1 , each of the wires of the plurality of wires comprising a wire resistance of about 10 Ω to about 12 Ω.
14 . The intravascular device of claim 1 , each of the electrically conductive cover material of the plurality of wires comprising a diameter measuring between about 0.0031 inches (79 micrometers) to about 0.0040 inches (102 micrometers).
15 . An intravascular device comprising:
an elongated shaft extending along a longitudinal axis and sized to traverse vasculature;
a distal section comprising a plurality of electrodes; and
a plurality of wires each electrically joined to a respective electrode of the plurality of electrodes, each of the wires of the plurality of wires extending through at least a portion of the elongated shaft, and each of the wires of the plurality of wires respectively comprising:
a plurality of strands, each strand respectively comprising an electrically conductive core material comprising a first electrical conductivity and an electrically conductive cover material comprising a second electrical conductivity less than the first electrical conductivity, the electrically conductive cover material circumscribing the electrically conductive core material, and
an insulative jacket circumscribing the plurality of strands so that no electrical arc is generated between the plurality of wires when at least 900 Volts is provided to each electrode.
16 . The intravascular device of claim 15 , the electrically conductive core material of each of the strands comprising about 41% silver (Ag).
17 . The intravascular device of claim 15 , each strand comprising a diameter measuring about 0.002 inches (51 micrometers).
18 . The intravascular device of claim 15 , at least a portion of the wires of the plurality of wires comprising exactly four (4) strands.
19 . The intravascular device of claim 15 , at least a portion of the strands of the plurality of strands comprising a resistance of about 20 Ω.
20 . The intravascular device of claim 19 , each of the plurality of wires being configured to withstand bipolar pulses resulting in a voltage difference of about 1,500 volts to about 2,000 volts between two wires in the plurality of wires.