CPC A61B 18/02 (2013.01) [G01R 33/285 (2013.01); A61B 2018/00041 (2013.01); A61B 2018/00791 (2013.01); A61B 2018/0212 (2013.01); A61B 2018/0262 (2013.01); A61B 2018/0293 (2013.01); A61B 18/08 (2013.01)] | 25 Claims |
1. A cryoprobe, comprising:
a probe shaft having a proximal section and a distal section opposite to the proximal section, the distal section being insertable into a patient, the probe shaft being made of a first material having a magnetic susceptibility of less than about 0.001 in S.I. units;
a cryofluid supply tube located within the probe shaft, the cryofluid supply tube being configured to receive a cryofluid from a cryofluid source, the cryofluid supply tube being configured to supply the cryofluid toward the distal section for cooling and/or freezing patient tissue; and
an electrical resistance heater wound around the cryofluid supply tube and comprising resistive elements having counter-wound helical coils located within the probe shaft, the counter-wound helical coils comprising a first set of coils wound in a direction counter to a second set of coils such that the first and second sets of coils are abutting and axially interspaced along the cryofluid supply tube, a number of coils of the first set of coils being balanced by a number of coils of the second set of coils such that when a single current is supplied to the electrical resistance heater, a first magnetic field generated by the first set of coils is counteracted and/or opposite to a second magnetic field generated by the second set of coils, the electrical resistance heater being made of a second material having a magnetic susceptibility less than about 0.0005 in S.I. units, the electrical resistance heater being configured to heat and thereby thaw, and/or cauterize tissue, when current is supplied thereto,
whereby the electrical resistance heater is configured to provide electrical resistive heating of tissue when positioned in a magnet room of a magnetic resonance imaging (MRI) system.
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