A magnetic field generating assembly, configured to be associated with a table supporting a body, the assembly comprising: a first plurality of elongate conductive elements arranged in a first plane , wherein each of the first plurality of elongate conductive element winds around a first central axis, extending perpendicular to the first plane , in a first spiral formation; and a second plurality of elongate conductive elements arranged in a second plane (57B 2 ), the second plane (57B 2 ) being substantially parallel to the first plane , wherein each of the second plurality of elongate conductive element winds around a second central axis, extending perpendicular to the second plane (57B 2 ), in a second spiral formation; wherein each of the first plurality of elongate conductive elements is interlaced with a corresponding one of the second plurality of elongate elements; wherein each of the first plurality of elongate conductive elements is electrically connected to the corresponding one of the second plurality of elongate conductive elements; wherein each of the first and second spiral formations is rectangular in shape; wherein a plurality of gaps is formed proximate each approximately 90 degree turn of the first and second spiral formations in which one of the first or second spiral formations crosses under the other of the first or second spiral formations, each gap being between successive windings of at least one of the first plurality of elongate conductive elements and the second plurality of elongate conductive elements; and wherein i) a width of each of the first plurality of elongate conductive elements is equal to or greater than a width of each of the plurality of gaps, or ii) a width of each of the first plurality of elongate conductive elements is less than a width of the each of the plurality of gaps, and wherein an isolated pattern of conductive elements fills each of the plurality of gaps . a first plurality of elongate conductive elements arranged in a first plane , wherein each of the first plurality of elongate conductive element winds around a first central axis, extending perpendicular to the first plane , in a first spiral formation; and a second plurality of elongate conductive elements arranged in a second plane (57B 2 ), the second plane (57B 2 ) being substantially parallel to the first plane , wherein each of the second plurality of elongate conductive element winds around a second central axis, extending perpendicular to the second plane (57B 2 ), in a second spiral formation; wherein each of the first plurality of elongate conductive elements is interlaced with a corresponding one of the second plurality of elongate elements; wherein each of the first plurality of elongate conductive elements is electrically connected to the corresponding one of the second plurality of elongate conductive elements; wherein each of the first and second spiral formations is rectangular in shape; wherein a plurality of gaps is formed proximate each approximately 90 degree turn of the first and second spiral formations in which one of the first or second spiral formations crosses under the other of the first or second spiral formations, each gap being between successive windings of at least one of the first plurality of elongate conductive elements and the second plurality of elongate conductive elements; and wherein i) a width of each of the first plurality of elongate conductive elements is equal to or greater than a width of each of the plurality of gaps, or ii) a width of each of the first plurality of elongate conductive elements is less than a width of the each of the plurality of gaps, and wherein an isolated pattern of conductive elements fills each of the plurality of gaps . <EOS>